28 September 2016, Volume 34 Issue 18
    

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  • Metamaterials to build the future
    ZHU Yehua
    Science & Technology Review. 2016, 34(18): 14-26. https://doi.org/10.3981/j.issn.1000-7857.2016.18.001
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    Metamaterial is a special kind of artificial composite materials or structures. Through orderly design the key physical size of the structure, we can design our own "atoms" to create the special material with unprecedented effective properties that have not yet been found in nature. Metamaterial like left-hand materials and photonic crystal have a wide range of applications in military and civil field. This paper reviewed the research progress and application of metamaterial.
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  • Recent advances on metamaterials
    MEI Zhonglei, ZHANG Li, CUI Tiejun
    Science & Technology Review. 2016, 34(18): 27-39. https://doi.org/10.3981/j.issn.1000-7857.2016.18.002
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    In this paper the current research and development of electromagnetic metamaterials are reviewed. Firstly, the definition, properties and classification of metamaterials are given. Secondly, commonly used effective medium theories are summarized, including Clausius-Mossoti equation, Maxwell-Garnett equation and its generalization, Bruggemann effective-medium expression, and the Polder-van Santen formula. Then, two retrieval methods for characterising electromagnetic parameters of metamaterials are presented, i.e., the method based on scattering parameters and another based on waveguide measurement. As for possible implementations of metamaterials, six types are demonstrated in the review, namely PCB based metamaterial, graphene based metamaterial, dc metamaterial, transmission-line based metamaterial, metamaterial using dielectric resonators, and anisotropic metamaterials using isotropic layered materials. Moreover, a twodimensional metamaterial, i.e. metasurface, and its working mechanism are also explained. More importantly, several typical applications of metamaterials are illustrated, which are the ultra-thin carpet cloak, microwave gateway, conformal surface plasmon polaritons, digital and programmable metasurface, dc cloak, and graphene based ultra-thin cloak, Luneburg lens, etc. Finally, future development of metamaterials is predicted.
  • Research progress of microwave tunable metamaterial absorber
    ZHOU Qian, YIN Xiaowei, ZHANG Litong, CHENG Laifei
    Science & Technology Review. 2016, 34(18): 40-46. https://doi.org/10.3981/j.issn.1000-7857.2016.18.003
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    With the development of electromagnetic interference protection technique and military stealth technique, absorbing materials have become an important subject of scientific research. In this paper, the principle of metamaterial absorber as well as the classification of absorbing materials is introduced, and the progress of microwave metamaterial absorbers designed for microwave frequencies is outlined. Particularly, theoretic and experimental studies on tunable metamaterial absorbers are summarized, and the development trend of metamaterial in tunable absorbers is prospected.
  • Exploration of 3D periodic structure frequency selective fabric based on U-taped velvet
    XIAO Hong, CHENG Huanhuan, SHI Meiwu, GUAN Fuwang, WANG Yajing, WANG Qun, TANG Zhanghong
    Science & Technology Review. 2016, 34(18): 47-53. https://doi.org/10.3981/j.issn.1000-7857.2016.18.004
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    This paper has prepared a three-dimensional periodic structure frequency selective fabric (3D FSF) based on U velvet by velvet weaving method, with the silver yarns as the conductive material. Compared with the planar dipole periodic structure with the same U velvet bottom length size, the U velvet of the 3D FSF is extended in the two ends of the dipole along the Z direction and has double frequency resonance in the 2~18 GHz. With the increase of the U velvet bottom length, the resonant frequency moves to the lower frequency. The number of U connectings does not affect the resonant frequency with the same bottom length. The resonance peak of the sample with silver fiber as the conductive material is sharper than that of the sample with stainless steel fiber as conductive material. For further study, a cross-shaped 3D FSF made of clustered U velvet unit is proposed. It is demonstrated that the design and control of the 3D FSF is very flexible.
  • Left-handed materials with ferromagnetic medium: A review
    LI Yang, LIU Chuanbao, BAI Yang, QIAO Lijie, ZHOU Ji
    Science & Technology Review. 2016, 34(18): 54-65. https://doi.org/10.3981/j.issn.1000-7857.2016.18.005
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    Metamaterials have been a hot issue in the international research community over the past decade, among which the left-handed material (LHM) is the most typical one that possesses simultaneously negative permittivity and permeability and has unique electromagnetic properties. Although the physical nature of the LHM is equivalent to the continuous medium, in fact LHM is made of artificial metal structure and the physical properties are determined by the parameters of the structure rather than the intrinsic property of the material. Utilizing directly the functional materials'intrinsic physical properties which can generate negative electromagnetic parameters so as to obtain the left-handed properties can greatly enrich the physical characteristics of the LHM and jump out of the scope of design of metamaterial, which is also the characteristic research field in the research field of the LHM. There have been many studies on LHM with ferromagnetic medium in recent years. In this article, we will review the progress of LHM with ferromagnetic medium.
  • Preparation and characterization of a bio-inspired ultra-black coating
    PAN Lei, LI Na, ZHANG Dayong, SUN Yunyong, LI Yao
    Science & Technology Review. 2016, 34(18): 66-69. https://doi.org/10.3981/j.issn.1000-7857.2016.18.006
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    The optical properties and microstructures of several black butterfy wings is investigated. The enhancement of optical absorption raised by the microstructures of black butterfly wings is universally observed. A general mechanism of this enhancement is proposed, based on which a bio-inspired ultra-black coating is fabricated with SiO2@C microspheres as absorbent. Through optimizing the coating formulation, the highest solar absorption ratio of the bio-inspired ultra-black coating is 0.9773, which is evidently higher than that of the traditional black coating with similar chemical ingredient.
  • New applications of metamaterials in tuning Casimir force
    YE Yingqi, GUO Hong, ZHAO Qian, MENG Yonggang
    Science & Technology Review. 2016, 34(18): 70-78. https://doi.org/10.3981/j.issn.1000-7857.2016.18.007
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    Along with the miniaturization of MEMS (micro-electro-mechanical system) components, the influence of adhesion failure in micro/nano systems caused by Casimir attraction becomes more and more important. An effective method to solve this problem is to reduce the attraction and achieve repulsion. In this paper the resource of Casimir force, its theoretical calculation, and the influence of electromagnetic parameters are studied, especially the application of electromagnetic metamaterials in Casimir force adjustment. The development of electromagnetic materials brings both opportunity and challenge to design and adjustment of Casimir force, along with controversial comments. More researches on general and systematical theoretical calculation, new construction of metamaterial models and experimental measurement with extra precision are desperately needed. The application of Casimir force will be universalized with these improvements.
    • Articles
  • Effects of femtosecond laser parameters on state populations of three-level ladder molecule
    GUO Wei, FENG Xiaojing
    Science & Technology Review. 2016, 34(18): 84-88. https://doi.org/10.3981/j.issn.1000-7857.2016.18.009
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    The effects of the pump intensity, the wavelength and the pulse width on the state populations of the three-level ladder K2 molecule driven by intense femtosecond pump-probe pulses are investigated by employing the time-dependent wave packet approach and are thus quantified. The Rabi oscillation is affected by the pump intensity, the wavelength and the pulse width, and its variation results in a periodical change of the populations in the ground state and the excited state. Quantifying their effects on the population of the excited state verifies the periodical nature and shows that the frequency varies with the increasing pump intensity and pulse width. The results illustrate that the needed population in the electronic state of interest can be obtained by controlling these parameters, which provides some important basis for light manipulation of molecular processes.
  • Magnetism of ferrofluids based on Ni-Fe oxide composite magnetic nanoparticles
    HAN Shaona
    Science & Technology Review. 2016, 34(18): 89-93. https://doi.org/10.3981/j.issn.1000-7857.2016.18.010
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    Ni-Fe oxide composite magnetic nanoparticles prepared by chemical co-precipitation method are introduced and ionic ferrofluids without surface-active agent is made by Massart method. The microstructure and grain size are analyzed through XRD, EDX, XPS and TEM, and the magnetization vs. magnetic field is measured by vibrating sample magnetometer (VSM, HH-15). The magnetizing curves have been fitted by using Langevin theory and gas-like compression model, respectively. The results indicate that there is an obvious deviation between Langevin theory and experimental data while the gas-like compression model can fit well, and that the compression parameter γ increases with the increasing ferrofluids volume fraction. The magnetization behaviors of Ni2O3/γ-Fe2O3 ferrofluids can be well illustrated by the field induced aggregation effect.
  • Metabonomic study of abnormal Savda rat model with asthma
    MAMTIMIN Batur, KURBANTAY Nazuk, HIZBULLA Mawlanjan, YOU Li, UPUR Halmurat
    Science & Technology Review. 2016, 34(18): 94-100. https://doi.org/10.3981/j.issn.1000-7857.2016.18.011
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    In order to standardize the syndrome of traditional Uyghur medicine, abnormal Savda rat model with asthma is selected as study subject and metabolic changes are investigated in animal model and clinical patient to reveal the similarity and difference between them. Sprague Dawley (SD) rats are subjected to abnormal Savda-producing conditions, followed by induction of asthma. Clinical patients of abnormal Savda with asthma are also selected as study subjects. Serum samples are collected from each test group and analyzed by nuclear magnetic resonance (NMR). Spectral profiles are analyzed by multivariate analysis using orthogonal projection to latent structure with discriminant analysis (OPLS-DA). Results show that compared with healthy controls, leucine, isoleucine, valine, alanine, lipid related metabolites like VLDL, and unsaturated lipids concentration in plasma of patients are decreased, but acetic acid, acetone, acetoacetate and carnitine are significantly increased; glutamate in patients also shows a significant increase while creatine, creatinine, scyllo-inositol and lactate are significantly reduced. For animal models, the change in concentration of lipid related metabolites and lactate, carnitine and glutamine is consistent with the clinical patient, but the amino acid displays an opposite trend. Alanine and creatinine concentrations are higher in plasma of abnormal Savda rat model compared to abnormal Savda with asthma rat model. It is concluded that although the amino acid metabolism in rat model is different from that in clinical patient, their changes of lipid related metabolites contents are highly consistent. Fat related metabolites may be considered biomarkers of abnormal Savda.
  • Investigation on aging and anti-aging of SBS modified asphalt
    HAN Mingzhe, LI Zuzhong, ZHAO Zepeng, ZHOU Hao
    Science & Technology Review. 2016, 34(18): 101-105. https://doi.org/10.3981/j.issn.1000-7857.2016.18.012
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    During the service of SBS modified asphalt, which is affected by interactions with heat, oxygen, light and traffic load, its road performance is degraded. Therefore, investigating its aging behavior is significant. This paper analyzes the influence factors of SBS modified asphalt aging, elaborates the evaluation indexes and methods of asphalt aging, and summarizes the thermo-oxidation aging mechanism and thermo-photo-oxidation aging mechanism for SBS modified asphalt. The results indicate that during the aging of SBS modified asphalt, asphalt components are aging themselves, meanwhile SBS is degraded, including transformation of light components into heavy components. Furthermore, improving the polymeric structure of SBS or blending stabilizers such as nanocomposites can effectively delay aging of SBS modified asphalt.
  • The physical environment of villages and towns in severe cold regions in China
    KANG Jian, JIN Hong, SHAO Teng
    Science & Technology Review. 2016, 34(18): 106-112. https://doi.org/10.3981/j.issn.1000-7857.2016.18.013
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    The outdoor physical environment of villages and towns in severe cold regions in China has not been paid a sufficient attention in the design and construction process. The traffic noise pollution, the loss of traditional soundscapes and the unsatisfactory wind environment are the major problems. Improvement of the physical environment is important to the living environment as well as the building energy reduction. This paper reviews the research progress of an on-going scientific and technical project in the national 12th five-year plan, including the noise control, the soundscape design and the wind environment improvements. The land-use pattern, the planning layout mode, the arterial road grade and form, the residential courtyard design, the plant configuration, and the protection and utilisation of natural sounds are discussed.
  • Experimental study on anti erosion of ecological slope in Qinghai-Tibet Plateau
    CEN Guoping, LI Lin, LIU Jiying, ZHAO Yun, LONG Xiaoyong
    Science & Technology Review. 2016, 34(18): 113-117. https://doi.org/10.3981/j.issn.1000-7857.2016.18.014
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    In order to decrease the impact of traffic engineering construction on the ecological environment of Qinghai-Tibetan Plateau, we have worked out the rainstorm intensity formula of three cities through analysis of the rainstorm characteristics of Qinghai-Tibetan Plateau area. Slope erosion tests of pure turf and three dimensional mesh cushion grass are performed, respectively with typical soil of the Qinghai-Tibetan Plateau. Thus we have gained two kinds of turf scouring velocities, which are compared with that of Xi'an loess. Considering the influence of slope micro topography, the slope flow is generalized as parabolic shallow channeling, and the relevant parameters are determined through field measurement.. In addition, combind with indoor scouring test's results an ecological slope protection scheme for the four regions is proposed, with calculation of slope flow parameters of Xining, Yushu, Lhasa, Delingha.
  • Identification of moisture sources in Junggar Basin and its implication for groundwater recharge
    LI Jie, PANG Zhonghe, TURSUN Gulbostan, KONG Yanlong, HUANG Tianming, BAI Guoying, ZHAO Hongyi, ZHOU Dong, YANG Zhongshan
    Science & Technology Review. 2016, 34(18): 118-124. https://doi.org/10.3981/j.issn.1000-7857.2016.18.015
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    Precipitation is the input of the water cycle, and stable isotopes of precipitation (18O and 2H) are powerful tools in tracing moisture sources and trajectories. In this paper, the characteristics of stable isotopes and deuterium excess in the precipitation are analyzed in the North Xinjiang based on observation data of four precipitation stations and HYSPLIT model. The local meteoric water line (LMWL) is established as δD=7.3δ18O+3.5, indicating the specific regional meteorological conditions. The Tianshan area and Altay area showed different isotopic characteristics due to different moisture sources. The monthly deuterium values in Tianshan area are low in summer and high in winter, which can be attributed to the seasonal drift of the westerlies. The monthly deuterium values in Altay area are constant due to the effect of arctic air mass. Although the monthly δ18O values in both areas are high in summer and low in winter, the amount-weighted averages are diverse, which makes it possible for identifying groundwater recharge areas. The intersection point of the evaporation line near Kelameili Mountain and LMWL has similar values of stable isotopes to the precipitation from Altay station, indicating that groundwater recharge from Kelameili Mountain. Groundwaters near East Tianshan Mountain have similar δ18O values, similar to the precipitation from Urumqi station, which suggesting groundwater in this area is recharged from East Tianshan Mountain.
  • On defending effects of different forest belt structures in Ulan Buh Desert
    DUAN Na, LIU Fang, XU Jun, CHEN Hailing, ZHANG Ge, HAO Yuguang
    Science & Technology Review. 2016, 34(18): 125-129. https://doi.org/10.3981/j.issn.1000-7857.2016.18.016
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    According to observations on wind velocities of different shelterbelts in Ulan Buh Desert, the paper shows that the defending effect varies with forest belt structure, height and porosity. Wind defending effect of sparse structure shelterbelt is the best, which is 41.37%, porous structure takes the second place, 29.58%, and ventilation structure is the worst, 23.92%. Shelterbelt with a porosity of 40%~50% has the best wind defending effect. With the increase of porosity, the defending effect decreases remarkably. So the structure should be sparse with a porosity of 30%~50%, and the porosity of forest canopy should be 30%~50% and the porosity of trunk, 50%.
  • Influence of Beijing vehicle restriction rule on air quality of hypo-artery road
    TAO Shuangcheng, DENG Shunxi, LIU Ning, GAO Shuohan, YAO Jialin
    Science & Technology Review. 2016, 34(18): 130-136. https://doi.org/10.3981/j.issn.1000-7857.2016.18.017
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    In order to investigate the effect of traffic restriction on ambient air quality in urban hypo-artery road, concentrations of PM2.5, NO2, O3, CH4 and NMHC (non-methane hydrocarbons) were constantly monitored during Aug. to Sep. 2015. Meanwhile, traffic flow was calculated, and the impact from the 2015 Beijing Parade traffic restriction on vehicle operating conditions and air quality in urban roads were studied. The limiting effects were obviously shown on buses and heavy trucks; 35.36%, 45.12%, and 94.23% traffic reductions were found on minibuses, medium buses, and heavy trucks, respectively during that period; while taxis and public transport increased. Pollutant concentrations varied significantly during and after traffic restriction. There was less change in methane concentration while concentrations of nitrogen dioxide and non-methane hydrocarbon were increased by 127% and 33.3%, respectivey. The ozone concentration was decreased by 27.7%. Pearson analysis reflected that the traffic flow had 1) a significant negative correlation with CH4 hourly concentration; 2) no significant correlation with PM2.5 concentration. A comparative analysis between monitoring data from background control point suggests that the traffic flow has significant correlation with the net contributions of NO2 and O3 concentrations from motor vehicles. During the Parade traffic restriction period, the average cut range of NO2 concentration on the monitored section was 51.25% while the average increase range of O3 concentration was 82.99%. Under the restriction and regional comprehensive emission reduction measures, an average cut range of 34.72% on PM2.5 was met.
  • Analysis of domestic haze research using mapping knowledge domain
    YAN Peisheng, YUAN Yongjiu
    Science & Technology Review. 2016, 34(18): 137-143. https://doi.org/10.3981/j.issn.1000-7857.2016.18.018
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    Taking the data of documents from CNKI database as the research sample, this article obtains a series of knowledge maps for the haze research of China. The results indicate that the research strengths are scattered. Although there are some collaborative researchers, but there is lack of long-term cooperation among the partners. The obvious core research strength in China has not been constructed. The main focuses of current haze research are mostly on the following issues:the causes of haze, the protection in haze whether, the harm of haze, the governance of haze and the early warning of haze.
  • Discussion on water environment problems and comprehensive countermeasures for Dongting Lake area
    TIAN Shiqiang, YANG Yi, LU Shaoyong
    Science & Technology Review. 2016, 34(18): 144-148. https://doi.org/10.3981/j.issn.1000-7857.2016.18.019
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    Based on the data from environmental monitoring and survey, several water environmental issues are identified in Dongting Lake area. The primary reasons causing these issues are analyzed from the aspects of hydrology change, pollution sources and environmental management. Furthermore, this paper also investigates the following ways to deal with these issues:increasing water environment carrying capacity by smoothing water network, reducing the amount of water pollutant generated, performing pollution source control and key areas renovating strategy, reducing the pollution from upstream areas, innovating environmental renovation mechanism and advancing the reform practice of ecological civilization system.
  • Water environment status and diagnosis of Sanxian Lake
    TIAN Shiqiang, CHEN Fangxin, LU Shaoyong, ZHAO Bin, YANG Yi, HUANG Chunlin, LI Yuanzhao, FENG Chuanping
    Science & Technology Review. 2016, 34(18): 149-155. https://doi.org/10.3981/j.issn.1000-7857.2016.18.020
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    Sanxianhu Lake's water quality and quantity relates to the drinking water in Nanxian County of Hunan province and the surrounding area's strategic security. For the watershed protection planning and policy making, surveys have been carried out to analyze Sanxianhu Lake water environment situation and diagnose its ecological environment problems. Results show that Sanxianhu Lake average concentration of total phosphorus is 0.18 mg/L and average concentration of total nitrogen is 1.26 mg/L, both meeting the V class of water quality. Compared with other major domestic lakes, it follows that Sanxianhu lake < Dongtinghu Lake < Poyanghu Lake < Taihu Lake in terms of total nitrogen, and Poyanghu Lake < Dongtinghu Lake < Sanxianhu Lake < Taihu Lake in terms of total phosphorus. Moreover, the polluted effect in sediments caused by total nitrogen is higher than that by total phosphorus. Compared with major domestic lakes in sediments, Dongtinghu Lake < Sanxianhu Lake < Poyanghu Lake < Taihu Lake in total nitrogen values, and Sanxianhu Lake < Poyanghu Lake < Dongtinghu Lake < Taihu Lake in phosphorus values. Sanxianhu lake is suffering from pollution problems including agricultural nonpoint source pollution, sediment deposition, internal pollution release risk, free range livestock and the fertilized pond fisheries.
  • Evaluation of ecosystem services function of the north shore of West Dianchi Lake Wetland Park
    MA Lan, LU Shaoyong, LU Yifeng, WANG Mengyun, MA Lijuan
    Science & Technology Review. 2016, 34(18): 156-161. https://doi.org/10.3981/j.issn.1000-7857.2016.18.021
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    Dianchi Lake is a famous plateau freshwater lake. Dianchi Lake Wetland Park is also the ecological resource with unique features and profound effects. Its function of ecosystem services contains nine kinds of values, which cover habitats, water quality purification, tourism and leisure, scientific research and education, air conditioning, biodiversity conservation, material production and water and soil conservation. Shadow engineering method, replacement method, and the results of reference method are adopted to evaluate the function values. It has been showed that the north shore of West Dianchi Lake Wetland Park provides 16.44 billion yuan annually, of which the maximum value belongs to the ecological habitat, accounting for 11.97 billion yuan annually. It may to great extent demonstrate a reference to assessing the value of ecosystem services for a similar case, so as to promot scientific and rational protection and sustainable development.
  • Research progress on the speciation of heavy metals in lake sediments
    BI Bin, LU Shaoyong, YU Yajun, REN Shanshan, GUO Likai, LIU Xiaohui
    Science & Technology Review. 2016, 34(18): 162-169. https://doi.org/10.3981/j.issn.1000-7857.2016.18.022
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    This paper reviews the recent research advances in heavy metal speciation in the sediments of lakes, and summarizes the morphological speciation characteristics of heavy metals in sediments from typical lakes in China. The percentages of heavy metals that can be extracted from sediments are different:the extractable Pb accounts for more than 50%, extractable Cd for more than 70%, and other extractable elements for much small percentages, most of which are in residual states. Different continuous extraction methods including Tessier, original BCR and improved BCR are compared. It is shown that the improved BCR has the best extraction effect, thus is being used widely, but its shortcoming is long extraction time. Using ultrasonic and microwave assisted method can greatly shorten the extraction time. The paper also describes the factors that influence heavy metal speciation in sediments, such as pH, oxidation reduction potential, particle size, organic matter content, etc. The advantages, disadvantages and applicable scopes of various evaluation methods are discussed based on speciation and biotoxicity. Finally, future extraction and analysis technology for heavy metal speciation in sediments and corresponding evaluation methods are prospected.
  • Watershed water environment pollution models and their application
    SUN Lifeng, WANG Yufan, LIU Xiaohui, LIU Ying, LU Shaoyong
    Science & Technology Review. 2016, 34(18): 170-175. https://doi.org/10.3981/j.issn.1000-7857.2016.18.023
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    The basin water environmental model is an important tool for water environment problem of river basin, which can provide a decision basis for planning and management. In this paper we firstly review river basin models of water environment pollution and water quality risk assessment. Secondly, on the basis of river basin water environment pollution load influence and water quality simulation for whole basin planning, we discuss and summarize the characteristics and applicability of various models of water environment including water pollution load model, water quality simulation model and water quality assessment. Thirdly, combined with agricultural areal source and urban areal source pollution load model, steady-state and dynamic water quality model, certainty and uncertainty evaluation model for water quality simulation, we analyze the development and importance of research and application in river basin water environment models. It is pointed out that we can provide reference data for total control by estimating the watershed pollutant emissions using water pollution load model; we can provide support for river basin water environment pollution control decision-making by effectively distinguishing the rules of migration of pollutants in the water with the water quality simulation model; and we can put forward new risk prevention and control strategies by identifying pollutant source and key risk areas through quality evaluation of water environment.
  • Groundwater pollution simulation analysis in chemical industry zone by means of GMS
    SUN Lifeng, WANG Chuang
    Science & Technology Review. 2016, 34(18): 176-181. https://doi.org/10.3981/j.issn.1000-7857.2016.18.024
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    GMS is the important groundwater numerical software to simulate groundwater flow distribution, migration of groundwater contaminants, etc. This paper takes the chemical plant zone as an example and uses GMS to predict the concentration of pollutants and the polluted area after generalizing the geological model, parameter identification, and adjusting-parameter processes. The effect of spread of the plant leachate on downstream pumping wells is studied, and.a factory model of groundwater flow and solute transport model are set up. Results show that the regional groundwater flows from north to south, and along the flow direction the water level decreases relatively moderately. Groundwater descent funnel is formed in the downstream pumping well. Pollutant concentration continues to increase, with local pollutant concentration as high as 4.1mg/L, which has gradually exceeded the scope of pollution. The pollution area is about 823509.67m2 and the downstream diffusion length is about 1084.64m. In the vertical direction, plant pollutants have spread to the second-level deep aquifer. If not controlled, the water output will intensify the pollutant diffusion velocity.
  • Research on widening visible light photocatalytic activity of TiO2 and application
    LIU Ying, LI Jianzhi, LU Chenggang, LIU Xiaohui, ZHANG Lingli, WANG Yufan, WANG Weiliang
    Science & Technology Review. 2016, 34(18): 182-189. https://doi.org/10.3981/j.issn.1000-7857.2016.18.025
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    In this paper, the mechanism of TiO2 photocatalytic reaction and the present modifying methods of TiO2 photocatalysis are discussed, including doping modifying, surface chelation and derivation, semiconductor compound, dye-photosensitization and conducting polymer modifying. And the effects of modifying methods on TiO2 photocatalysis activity are analyzed. Applications of modified TiO2 photocatalysis oxidation are reviewed. At the end of the paper, research and application prospect of titanium dioxide are depicted.
  • Experiment and numerical simulation of lignite for spontaneous combustion
    ZHANG Xiaoming, ZHANG Hemeng, WANG Zhuo, WANG Yongjun, SASAKI Kyuro
    Science & Technology Review. 2016, 34(18): 190-193. https://doi.org/10.3981/j.issn.1000-7857.2016.18.026
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    This paper investigates the characteristics of lignite spontaneous combustion, with coal samples piled in cube mesh-boxes of three different sizes, placed in a constant temperature chamber and tested by the isothermal heating method. The temperature-time traces and the critical self-ignition temperature in different size coal piles are obtained. The critical self-ignition temperature is lower for larger stockpile volumes. The heating curves of coal will reach the ignition point when the set ambient air temperature is higher than the critical self-ignition temperature. On the other hand, the coal sample will not be self-ignited. Based on the conditions of the experiment, the temperature field, the air seepage field and the oxygen concentration field are simulated by the Fluent software. The three fields change with time and interact with each other in the entire experiment process.
  • Sedimentary composition and forming models of Miocene reef carbonate: A case study of Xisha waters
    ZHAO Xinwei, XU Hong
    Science & Technology Review. 2016, 34(18): 194-202. https://doi.org/10.3981/j.issn.1000-7857.2016.18.027
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    The characteristics of sedimentary composition and evolution models of the Miocene reef are studied by combining the latest drilling data and seismic data. The reef-building organisms in the studied area are mainly calcareous alga, followed by hexacorallia; and accessory reef organisms mainly consist of the foraminifera and ostracod. According to the development of reef-building organism rocks which can be divided into reef skeleton-framestone and non-reef skeleton-framestone, the former includes red coral and reef framework dolomite and red algal-halimedadolomite, and the non-reef skeleton-framestone mainly consists of bioclastic limestone, grain of marl and packstone. The sedimentary facies include reef framework, reef flat, lagoon, backreef bank and bioclastic facies. The sedimentary evolution of Miocene organic reef follows the rising of the relative sea level, then a set of aggradation-retrogradation reef sedimentary cycles. The reef development can be mainly divided into four stages:the foundation, initial prosperity, peak and expose recession. During the fourth stage for reef and development, the favorable reservoir in studied area was formed by extensive dolomitization of exposure shoals.
  • Storm deposits in wide and shallow lacustrine environment in Yanchang Formation, Ordos Basin
    ZHOU Xiaofeng, LIU Lili, WANG Jianguo, DAI Jinyou, LAN Chaoli
    Science & Technology Review. 2016, 34(18): 203-208. https://doi.org/10.3981/j.issn.1000-7857.2016.18.028
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    Through the core observations, storm deposits are found in Chang 8 of Yanchang Formation, Ordos Basin, with features including the etching structure, the hummocky cross stratification, the ailochthonous coal, the storm lag deposit, and the Fugichnia. The deposits are developed by the tempestuous currents retransporting and redepositing the delta sediment near the lacustrine shoreline. Their vertical sedimentary sequence consists of seven lithofacies units from A to G. Toward the lacustrine centre, the storm lag deposits and the massive sandstones gradually decrease and correspondingly, the hummocky cross stratification and ripples increase. It is shown that the distinctive storm deposits are developed in the wide and shallow lacustrine environment. The multi-stage deposits are overlain in the vertical section and the fully reconstructed shallow delta sediment is in the horizontal section, with rich sandstones being raised in the whole basin to provide a new reservoir. This study is conducive to the formation of the large lithologic reservoirs and to a new field for the petroleum exploration in Ordos Basin.
  • Characteristics and origins of mixed sediments in Batken region of Fergana basin
    ZHANG Liyuan, LIU Ying, BU Xiaoyang, LIU Ke, GAO Fei, CHEN Lingling, LIU Zhen
    Science & Technology Review. 2016, 34(18): 209-220. https://doi.org/10.3981/j.issn.1000-7857.2016.18.029
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    By means of various data and measurements such as rock cores, well logging, mud logging, cast thin-sections and scanning electron microscope, this paper investigates the characteristics and origins of mixed sediments and their relation with petroleum-gas resources from Cretaceous-Paleocene in Batken region of Fergana basin in the central Asia. It is considered that mixed sediments from Cretaceous-Paleocene in the research area developed with two forms:mixed rocks and mixed layer series. The mixed rocks are dominantly terrigenous clastic bearing-carbonate rock and terrigenous clastithic-carbonate rock. And the mixed layer series are mainly carbonate rockmixed rock layer series and terrigenous clastic rock-mixed rock layer series. The mixed sediments in the research area are widely distributed in various environments, including restricted platform, evaporated platform, barrier coast and neritic shelf. Furthermore, the main origin of the mixed sediments is facies mixing, followed by in situ mixing and punctuated mixing. In addition, the mixed sediments in the research area made some contribution to source-reservoir-cap rocks. To be more specific, the marlite of Paleocene is one of the main source rocks as well as regional cap rocks for the research area. Besides, the limestone reservoirs of Paleogene and Cretaceous are not pure carbonate rocks. Instead, most of them are mixed rocks or part of the mixed layer series.
  • Zircon U-Pb dating and its trace element analysis applied to geology
    YANG Fu, CHEN Gang, ZHANG Wenlong, TIAN Wen, TIAN Tao, ZHAO Xuejiao
    Science & Technology Review. 2016, 34(18): 221-229. https://doi.org/10.3981/j.issn.1000-7857.2016.18.030
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    Zircon U-Pb dating and trace elements in situ microanalysis is one of the most widely used methods of geological dating. The zircon morphology, internal structure and geochemistry significance in-depth study are the key to properly understanding and interpreting the meaning of in situ microanalysis zircon dating. By zircon cathodoluminescence, backscattered electron images, combined with zircon Th/U ratios and the characteristic of REE distribution patterns, we can determine different types of zircon. Zircon trace elements can reflect genetic types and environment of host rocks. Zircon Ti thermometer may limit the depth of the magma source rock range. Combining zircon host rock types and the study of deep source inclusion in host rocks may further reflect the parent magma origin. Combination of zircon UPb dating and trace elements is an important method that has been successfully applied to determining maximum depositional age, provenance analysis, closure time of the paleo-ocean and so on. There is a strong development prospect for it.
  • Characteristics and geological significance of calcite dissolution under acetic acid conditions
    WANG Mingge, SONG Tushun, XU Jiuhua, LI Zhanfang, TIAN Zhuang, LIU Shengchang
    Science & Technology Review. 2016, 34(18): 230-235. https://doi.org/10.3981/j.issn.1000-7857.2016.18.031
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    Since it is difficult to identify microscopic petrographic features of calcite dissolution, we take, pure calcite as the research object, and base on the Fuyu reservoir geological conditions of Songliao basin to study the calcite dissolution characteristics and geological significance through acetic acid-calcite interaction experiments. Results show the followings. Ccalcite is found of having different scale dissolutions and mass losses in different temperatures; ion concentration show regular changes, with Ca2+ ion concentration being 684.68~1255.25 mg/L, HCO3- ion concentration 2239~3821 mg/L, salinity 3088~5456 mg/L; calcite dissolution microscopic features include residual cone, residual fine crystal imbricate arrangement, dentate residual cone, tumor residual cone, residual sharp cone, etc.; under the acetic acid condition the most suitable temperature for calcite dissolution is 100~130℃. This study provides a certain theoretical basis for the identification of geological features of calcite dissolution reservoir and the function of reservoir into rock, and secondary porosity prediction.
  • Research progress in reservoir automatic history matching
    WANG Mingchuan, DUAN Taizhong, SUN Hongjun, ZHANG Junfa
    Science & Technology Review. 2016, 34(18): 236-245. https://doi.org/10.3981/j.issn.1000-7857.2016.18.032
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    Automatic history matching (AHM) of reservoir has made great progress in both theory and application since its proposal more than 50 years ago. In order to summarize the research progress and key technologies, this paper takes the development history of AHM for the mainline and the technical progress of AHM as the core, and divides AHM into four stages:germination, formation, development and rapid development. It then systematically discusses the general optimization methods and the potential optimization methods. A comparison for these optimization algorithms is given in terms of characteristics and applicable scopes. and problems existing in current research are also presented. Finally, future direction of AHM is put forward.
  • Experimental study of mechanical properties of rocklike specimens containing single cracks of different inclination angles under SHPB loading
    WANG Weihua, LI Kun, WANG Xiaojin, JIANG Haitao, YAN Zhe
    Science & Technology Review. 2016, 34(18): 246-250. https://doi.org/10.3981/j.issn.1000-7857.2016.18.033
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    In order to study the influence of the crack obliquity on the strength, the deformation, the crack propagation and the failure process of rocklike specimens, the SHPB loading test is carried out for rocklike specimens, with prefabricated cracks containing different inclinations. It is found that the strain phase segment is not obvious under the SHPB loading and the strain softening stage and residual strength section are almost of non-existence. Under the SHPB loading, the peak strength of the rock specimens is almost the same as that under the static loading, that is, it is in a V shape against the angle of the rocklike specimens and it increases before it decreases. The peak strength of the specimens is the minimum, when the crack obliquity is 45°, and the peak strength of the specimens is very close to that of the complete specimens when the crack obliquity is 0° or 90°. The strength of the rocklike specimens under the SHPB loading increases slowly and the peak strength is less than the peak strength under the static loading under the same condition. The crack angles decrease with the increase of the prefabricated crack inclinations. When the prefabricated crack inclinations are relatively small (0°,15°), the crack angle is close to 90°. This trend is consistent with the static loading. The SHPB loading process is different from that of the static loading, it lasts about 2s from the beginning of the loading to the complete failure of the rocklike specimens, with an extremely fast speed.
  • Hydrodynamic performance research of offshore oil and gas exploitation TLP
    GUO Ting, QIN Hongde, LI Xiaoyong, WANG Chong
    Science & Technology Review. 2016, 34(18): 251-257. https://doi.org/10.3981/j.issn.1000-7857.2016.18.034
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    The offshore oil and gas exploitation TLP's hydrodynamic performance is computed, and analyzed by using 3-D potential theory, API of wind and JONSWAP of wave in terms of hydrodynamic coefficients, 1st-order wave load, 1st-order motion response and 2ndorder difference frequency wave load. The results indicate that the 1st-order wave load on TLP of the out-of-plane presents a rapid decreasing trend with the increase of wave frequency. Heave/roll/pitch reach their peaks at the wave frequency 0.4 rad/s, the heave displacement is no more than 5% of water depth and the roll angle less than 5°. It is shown that TLP can effectively avoid wave/wind frequency concentrated areas, and safely work in variety of sea conditions. The 2nd-order difference frequency wave load in the y direction is about 4 times as large as the force in the x direction. Compared with the 1st-order wave loads, the 2nd-order difference frequency wave load is relatively small, but the damage for TLP can not be ignored.
  • Research and test on China high-speed railway earthquake early-warning system
    LU Chunfang, ZHOU Li, ZHANG Zhifang
    Science & Technology Review. 2016, 34(18): 258-264. https://doi.org/10.3981/j.issn.1000-7857.2016.18.035
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    The urgent development target of the China high-speed railway earthquake early-warning system (CRES) is analyzed, and the latest progress on the research and test verification are introduced in this article. At the same time, the research target and early-warning methods are described. Based on the breakthrough of P wave early-warning method and earthquake emergency treatment method, the reasonability of CRES has been verified by laboratory experiment, and field tests on Fuxia high speed railway (Fuzhou-Xiamen), Chengguan high speed railway (Chengdu-Guanxian), and Daxi high speed railway (Datong-Xian), as well as by the field experience about natural earthquake. The results show that its functionality and performance can meet the corresponding requirements, and that the stage target is reached. At last, the development direction is proposed.
  • Inverted robot design and realization with rapid control prototyping
    LÜ Qiang, ZHANG Yang, WANG Guosheng, GUO Feng
    Science & Technology Review. 2016, 34(18): 265-269. https://doi.org/10.3981/j.issn.1000-7857.2016.18.036
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    Rapid control prototyping is introduced in terms of its generation, development and advantage. A hardware platform for inverted robot's rapid control prototyping is established and its design flow is summarized. Then a Matlab/Simulink model is designed and automatic code generation is realized to control the inverted robot. Simulation results show that the inverted robot can keep balance in the range between -2 and 2 degrees, which demostrates the advantage of the rapid control prototyping. In the initial step of the design procedure the Matlab/Simulink model can be tested in real situation so as to reduce the design cycle, save cost and speed up development efficiency.
  • Measuring FAST cabin-cable system model's vibrations using binocular camera's technology
    CUI Ximin, WANG Qiang, LI Hui, FAN Shenghong, ZHENG Ke, QI Xiaotong
    Science & Technology Review. 2016, 34(18): 270-274. https://doi.org/10.3981/j.issn.1000-7857.2016.18.037
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    It is the foundation to realize closed loop control that the FAST telescope feed cabin-cable's location and vibration frequency are dynamically measured. Due to the fact that traditional measurement methods for FAST telescope cabin-cable scaled model's vibration frequency measuring are of complicated operation, large disturbance, and difficult to realize, a high-speed dynamic frequency-measuring method based on binocular camera is put forward to cope with the characteristics of continuous changes in the vibrating object to be measured, It calculates object's three-dimensional coordinates, and uses fast Fourier transform to obtain the spectrum of real-time discrete point locations. Then the vibration frequency is analyzed. Experiments show that in the case of frequency's resolution being 0.04 Hz, the repeated measurement and time-segmented measuring errors of binocular camera high-speed dynamic frequency measuring are not greater than 0.08 Hz and 0.04 Hz, respectively, indicating that for low frequency vibrating objects like the feed cabin cable, this method can effectively satisfy the requirement of dynamic frequency measuring.
  • A visual navigation control system for autonomous multi-rotor aircraft
    WANG Guosheng, GUO Feng, LÜ Qiang, ZHANG Yang
    Science & Technology Review. 2016, 34(18): 275-278. https://doi.org/10.3981/j.issn.1000-7857.2016.18.038
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    Aimming at multi-rotor aircraft localization and autonomous fight in GPS-denied environments, we describe a multi-rotor unmanned aircraft control system based on visual navigation. Our system is equipped with a popular pixhawk flight control module and monocular visual localization algorithm, and a communication network system is established based on robot operating system(ROS). We use an onboard computer with low power consumption which deals with all the necessary real-time operations for the system.. Test results show that our multi-rotor aircraft platform can achieve accurate visual localization and autonomous flight.
  • Dynamic responses of a concrete slab subjected to air and underwater explosions
    KONG Xiangqing, ZHAO Qian, QU Yandong, ZHANG Wenjiao
    Science & Technology Review. 2016, 34(18): 279-286. https://doi.org/10.3981/j.issn.1000-7857.2016.18.039
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    The numerical simulation models for explosions in air and water are established by using the finite element software ANSYS/LSDYNA. The explosion shock wave speeding characteristics in different media are compared, and the dynamic responses of the reinforced concrete slab in a typical air explosion and an underwater explosion are investigated. Furthermore, the dynamic response of the air and underwater explosive loads is analyzed in the cases with different amounts of explosive and at different initiation distances. It is shown that the explosion shock wave propagation is faster in the air than in the water; and the shock wave pressure is more quickly attenuated in the water. But the pressure peak of the shock wave in the water is larger than in the air. An underwater explosion may cause a significant damage to the concrete slab. The dynamic response of a concrete slab subjected to an underwater explosion is significantly higher than that for an air blast with the same mass of charge, both on the surface and on the back of blasting.
  • Simulation study on position and force feedback control for active suspension system with electro-hydrostatic actuator
    ZHANG Peipei, YU Qiang, LEI Liangyu, ZHAO Xiangjun, ZHOU Chenyu
    Science & Technology Review. 2016, 34(18): 287-292. https://doi.org/10.3981/j.issn.1000-7857.2016.18.040
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    This paper discusses a multi-closed loop control strategy for an active suspension system of a quarter car model operated by an electro-hydrostatic actuator to trade-off between vehicle handling stability and passenger comfort. In order to provide a desirable dynamic behavior of hydraulic active suspension, the closed loop control strategy using fuzzy position feedback controller and linearization force feedback controller and referring to robot compliant control is proposed. The fuzzy position controller is to track a desired body displacement given by the impedance control and the linearization force controller to track a desired force. By using Matlab/Simulink, a vehicle model of suspension system for B road with 0.1 m hump road disturbance is simulated. The result shows that the root mean square values (RMS) of body vertical acceleration, suspension dynamic deflection and tire dynamic load of the active suspension system have been reduced compared to the passive suspension, greatly improving the vehicle handling stability and passenger comfort.
  • Multi-objective decision-making methed in liquid cargo replenishment schemes
    DENG Wei, HAN Duanfeng, YAO Jingzheng, JIN Xin
    Science & Technology Review. 2016, 34(18): 293-298. https://doi.org/10.3981/j.issn.1000-7857.2016.18.041
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    For solving decision problem about liquid cargo replenishment scheme, the mathematic model of scheme-decision problem is built based on weighting method. In order to simplify the model, the multi-objective problem (MOP) can be change into a single objective problem (SOP). The weight matrix of three sub-object is determined through analysis hierarchy process (AHP). Permutation and combination method is used to find all possible replenishment schemes and technique for order preference by similarity to an ideal solution (TOPSIS) theory and particle swarm optimization (PSO) algorithm are taken into the mathematic model to calculate best solutions from possible replenishment schemes respectively. The simulated numerical results indicate that the effectiveness of mathematic model and reliability of algorithm proposed in this paper, also can improve efficiency and security of liquid cargo replenishment.
  • Smart grid practices in Germany
    LI Huijie
    Science & Technology Review. 2016, 34(18): 299-303. https://doi.org/10.3981/j.issn.1000-7857.2016.18.042
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    Germany keeps a leading place in renewable energies, where the smart grid plays a key role in managing the demand and the volatile green energy supply. Germany and China face many similar challenges in energy issues, therefore, China might learn from the German experience with respect to the smart grid development:making full use of local renewable resources and then reducing the use of fossil fuels, to not only cut down CO2 emissions, but also improve the air quality, and less energy import means more energy independence and more security. Some big events or policies relevant to the smart grid development in Germany are reviewed in this paper. Field tests relevant to smart grid applications in Germany are found to focus mainly on the integrated system and the customer behavior. The smart meter as a key part of a smart grid has received some attention too. And the grid automation distribution, the grid automation transmission and the storage technology demonstration are planned to be tested in practice. In the field projects, apart from the traditional big four utility companies, Germany pays more attention to involve customers and small and medium-sized enterprises, which is an indispensable part of the innovation diffusion. Smart appliances need smart consumers. Besides the policy incentive, the user experience matters a great deal for a new product. The green energy creates many job opportunities. More investment possibilities like in the cooperatives could be provided in wind or solar parks. Supported by users and investors, new technologies have a better chance to hold a place in the market. In addition, German E-energy pilot projects provide some precious experience in the smart grid. The information and communication technology makes the energy system transparent and intelligent with respects to regional marketplaces to bring together consumers with shiftable loads, producers, energy service providers and grid operators. Electronic meters could provide the real-time information on major parts of the grid, which helps the optimization of the whole system. The demand side management (DSM) as one kind of flexibility resource, is very important for balancing the electricity generation and consumption. The potential of the DSM in the Chinese residential sector is great.
  • Evaluation system and relative green degree of environmentally oriented design based on fuzzy AHP-TOPSIS
    CHEN Jian, ZHANG Shengliang, LI Xin, CHEN Kun
    Science & Technology Review. 2016, 34(18): 304-313. https://doi.org/10.3981/j.issn.1000-7857.2016.18.043
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    To solve the problems of the index's fuzziness and the corresponding weight's incompleteness in the evaluation of various schemes of mechanical products in an environmentally oriented design, a synthetical study method of the relative green degree based on the fuzzy AHP-TOPSIS is developed to improve the related solutions. The advantages of the fuzzy AHP and the fuzzy TOPSIS are well combined. Firstly the fuzzy AHP is applied to divide the indexes into an orderly hierarchy to determine the weight of each hierarchy level. Then the fuzzy AHP-TOPSIS is established combined with the fuzzy AHP to determine the optimal scheme according to the degree of closeness between certain qualitative and quantitative indices of benefit and of cost and the ideal solution. Both the quantitative and qualitative indices of benefit and of cost are distinguished strictly, and the principle and the systems of index evaluation of mechanical products by environmentally oriented design are established based on the full life circle. The case analysis shows that it is reasonable in theory and functional in practice, as a result, it is effective and feasible.

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