08 October 2014, Volume 32 Issue 28/29

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  • LU Yongxiang
    Science & Technology Review. 2014, 32(28/29): 15-26. https://doi.org/10.3981/j.issn.1000-7857.2014.28/29.001
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    Human is going into a green, low carbon, sustainable energy era, which will mainly rely on renewable energy. To promote the construction of green, low carbon, smarter, safety and sustainable energy systems, this article reviews the development history of clean, renewable energy utilization from a viewpoint that almost all energy sources on earth mainly come from the solar energy. A brief history of energy utilization is included and the development potential and future of renewable energy are discussed. The paper also points out that in the future human should further innovate to develop solar energy, strive to develop wind power, continue to develop water power, adjust measures to local conditions for the development of biomass energy, and actively develop the hydrogen energy and nuclear power on a basis of secure and efficiency.
  • Articles
  • FAN Bin, CHU Deren, SHANG Zhaocong
    Science & Technology Review. 2014, 32(28/29): 32-38. https://doi.org/10.3981/j.issn.1000-7857.2014.h1.003
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    The most wildly used analytical method for determination of water-soluble potassium content in fertilizers and soil conditioners, namely the potassium tetraphenylborate gravimetric method, is systematically studied and improved, and the procedure of masking ammonium by adding formaldehyde is abolished. Comparative experiments on both reference materials and a series of fertilizer samples show that the newly-developed method is more accurate than the former method, and of compatible precision. Recommended by the ISO Technical Committee 134 (Fertilizers and Soil Conditioners), an international ring test with 14 participating labs around the world is conducted by the Shanghai Research Institute of Chemical Industry. Statistical analysis reveals that the new method is both universal and precise, thus it will be approved as the next-generation analytical method for the new ISO standard.
  • WUSHUER Palidan, HIZBILLA Mawlanjan, AMAT Nurmuhammat, UPUR Halmurat
    Science & Technology Review. 2014, 32(28/29): 39-47. https://doi.org/10.3981/j.issn.1000-7857.2014.h2.004
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    To investigate the metabolic characteristics of alzheimer's disease (AD) rat model with abnormal savda syndrome, an abnormal savda rat model with multiple factors is established according to the theory of Uighur traditional medicine, and Aβ1-40 ventricle injection is carried out to establish the alzheimer's disease rat model with abnormal savda syndrome. Then, serum samples from all group rats are analyzed by nuclear magnetic resonance (1H-NMR) spectroscopy (600 MHz), and their spectral profiles are projected by orthogonal projections to latent structures (OPLS-DA) for multivariate statistics. The OPLS-DA analysis shows that compared to the normal group, the pure AD group serum has higher levels of lactic acid, glycoproteins, acetone, VLDL, formic acid and unsaturated lipids, yet a lower level of malonic acid. The abnormal savda syndrome group serum has higher levels of glycoproteins and β-glucose, but lower levels of valine, tyrosine, phenylalanin, and 1-methyl-histidine. The anormal savda syndrome AD group serum has a higher level of unsaturated lipids, but lower levels of glycine, phenylalanine, 1-methyl-histidine, methionine, malonic acid, α-glucose and β-glucose (P<0.05). Compared to the pure AD group, the abnormal savda syndrome group serum has lower levels of leucine, valine, alanine, tyrosine, α-glucose, β-glucose, carnitine, citric acid and unsaturated lipids. The abnormal savda syndrome AD group serum has lower levels of alanine and acetone, but higher levels of β-glucose and creatine (P<0.05). Compared with the abnormal savda syndrome group, the abnormal Savda syndrome AD group serum has higher levels of α-glucose, β-glucose, carnitine and citric acid (P<0.05). It is concluded that the abnormal savda syndrome has certain relevance to the development of alzheimer's disease; compared with the abnormal savda syndrome group and pure AD group, the alerted metabolits and metabolic pathway related with disordered glucose metabolism and energy dysmetabolism have variations during the pathological changing process of disease, and the variation of metabolism in the body of abnormal savda syndrome AD rat is more complex.
  • WANG Weihua, WANG Xiaojin, JIANG Haitao, YAN Zhe, LI Shuangrong
    Science & Technology Review. 2014, 32(28/29): 48-53. https://doi.org/10.3981/j.issn.1000-7857.2014.h2.005
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    The effect of crack inclination angle on strength, failure mode, failure process, law of crack initiation and propagation is studied by uniaxial compression test on rocklike specimens with single pre-existing cracks of different inclination angles. It has been found that the stress-strain curve of the cracked specimen goes through five stages: compressive densification stage, stable linear elastic stage, crack extension stage, strain softening stage and residual strength stage, which is similar to the intact sample. The peak compressive strength of the cracked sample changes as a V-shaped curve with the increase of the crack inclination angle, and the minimum peak compressive strength is at the angle of 45° and the maximum compressive strength at angle 0°or 90°. The crack initiation angle decreases gradually with the increase of the crack inclination angle; on the contrary, the initiation speed and stable propagation speed of the crack increase with the crack inclination angle. The crack starts to expand with the increasing load gradually. The crack extension is stable and not obvious at first, when the load reaches a certain value, the crack expands quickly until the cracked specimen is broken completely.
  • YANG Zhaopeng, SHA Yanhong, LIU Shangqi, HAN Bin, YANG Yuanming, LIU Jian, LIANG Guangyao
    Science & Technology Review. 2014, 32(28/29): 54-58. https://doi.org/10.3981/j.issn.1000-7857.2014.h2.006
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    The gas percolation mechanism is a theoretical basis for accurately establishing the seepage model, evaluating productivity and developing gas reservoirs. The mechanisms of stress sensitivity, slippage effect, and high-speed flow in the Sulige tight gas reservoir are studied in order to confirm the flow behavior of the single-phase gas. The method of confining pressure unchanging-pore pressure changing is adopted to evaluate the stress sensitivity of the Sulige tight gas reservoir. The stress sensitivity of tight gas reservoir is proved to be strong. The effective stress coefficients of Suilge tight gas reservoir samples are obtained through Brace method. The minimum pressures in which the slippage effect will disappear are studied in the condition that the effective stresses on rock samples are constant. The minimum pressure decreases with the increase of reservoir permeability. Seven rock samples are adopted in the experiment to study the high-speed flows in tight gas reservoir and low permeability gas reservoir. In the low permeability rock samples, the gas flow exhibits the high-speed non-Darcy behavior. But due to the very low permeability, the gas flow rate is restricted in tight gas reservoirs, and the flow still belongs to Darcy-flow under a sufficiently high pressure difference. Thus, there exists no high-speed flow in the matrix of tight gas reservoirs.
  • ZHAO Yuji, WANG Xuewu, LING Haochuan
    Science & Technology Review. 2014, 32(28/29): 59-63. https://doi.org/10.3981/j.issn.1000-7857.2014.h2.007
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    Based on the precise measurement of the micro flow by the photo-electric micro meter, a method to measure the differential pressure flow curves of tight oil cores is proposed in this paper. The influence factors, such as throat radius, micro fracture and fluid property, on the porous flow law of tight oil reservoir and the start-up pressure gradient are analyzed. The results are as follows. The essence of nonlinear flow in tight oil core is that the cores are composed of different levels of the throats. The real startup pressure gradient and the maximum throat radius have a good power-law relationship, and the pseudo start-up pressure gradient also has a power-law relationship with the average throat radius. The core with micro facture has smaller real & pseudo start-up pressure gradients than the core without any micro fracture. The real and pseudo start-up pressure gradients will be greater when using formation oil than those when using formation water in the experiment. The lower the permeability of the core, the greater difference of the real and pseudo start-up pressure gradients.
  • WANG Shenglan, LIU Hui
    Science & Technology Review. 2014, 32(28/29): 64-69. https://doi.org/10.3981/j.issn.1000-7857.2014.h2.008
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    The Kaiping Depression is located on the western Zhujiangkou Basin. It is a Paleogene faulted basin in the NE-ENE direction. Based on results obtained from drills and seismic reflections, five sedimentary facies are identified in the Enping Formation. The shallow lake facies is seismic facies characterized by medium frequency, strong amplitude, continuity and parallel sheet, distributed in the center depression. Littoral lake facies includes seismic facies characterized by medium-high frequency, medium amplitude, continuity, and sub-parallel sheet, on-lap seismic facies characterized by medium frequency, medium-week amplitude and medium continuity, and micro-waved seismic facies characterized by medium-high frequency, week amplitude and medium continuity, deposited on the southwestern depression. Delta facies includes progradation seismic facies characterized by high frequency, varying amplitude and medium continuity and weak-progradation seismic facies characterized by medium-high frequency, medium-week amplitude and medium continuity, mainly developed on the east and northeast. Fan delta facies is tangle-some wedge seismic facies,,characterized by low frequency, week amplitude, and low continuity, distributed on the down-thrown sides of west depression-controlling faults. Alluvial fan facies is tangle-some filling seismic facies, characterized by low frequency, week amplitude, low continuity, limited on the up-thrown side of a west depression-controlling fault.
  • ZHANG Xinchao, SUN Zandong
    Science & Technology Review. 2014, 32(28/29): 70-74. https://doi.org/10.3981/j.issn.1000-7857.2014.h2.009
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    A new method for fracture prediction is proposed in this paper, to identify the distribution of carbonate fractures developed under the multi-stage stress action in the North Slope, Tazhong area. Studies show that fractures are developed in a single-azimuth set and a multiple-azimuth set in carbonate rock there. The predicted fractures with the post-stack coherent attribute are mostly distributed around faults, and developed in fault-fracture zones. These fractures are always in a multiple-azimuth set, because they are developed in two main directions by the relief of dipole-stresses. And the fractures predicted by the P-wave azimuth AVO inversion are always developed in the tops of the anticline and the uplift belt. They are always in a single-azimuth set, because they are developed by a persistent and single northeast directional stress relief. Further analysis shows that the prediction results with the post-stack coherent attribute could be used to describe the relation between fractures and faults, while the results of the pre-stack method could be used to describe the fracture distribution between faults. And the integrated prediction results not only more accurately reflect the fracture distributions, but also are consistent with the geological conditions of the North Slope in Tazhong area.
  • LI Jun, QIN Chaokui, YAN Mingqing
    Science & Technology Review. 2014, 32(28/29): 75-78. https://doi.org/10.3981/j.issn.1000-7857.2014.h2.010
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    Urban gas facility is one of the urban lifeline engineering and many variables affect buried gas pipeline failure. To analyze the influence of randomness and uncertainty of variables on the safe operation of urban gas pipeline, the reliability theory and its application in pipeline are studied. Moreover, buried pipe failure model is established and various factors affecting the structural reliability of the urban high-pressure gas pipeline are analyzed, under the design pressure of 4.0 MPa, using the advanced First Order Second Moment (FOSM). The results show that, the influences of variables on the buried gas pipeline reliability are in the following descending order: the material yield strength, the pipe wall thickness, the internal fluid pressure, the vertical load, the bendingmoment coefficient, the pipe diameter, the deflection coefficient, the elastic modulus and any other factors. Keeping the variation coefficients at a constant of 0.05, the pipe reliability index increases with the material yield strength, the pipe wall thickness, the deflection coefficient, and decreases with other variables mentioned above. At the same time, the reliability index is related with the variation coefficient, the greater the variation coefficient, the smaller the reliability index. This conclusion is substantiated not only for the parameters positively correlated with the failure probability, but also for the parameters inversely related to the probability. Finally, some suggestions are provided to improve the structural reliability analysis of the urban high-pressure gas pipeline.
  • LUO Zhouquan, QI Feixiang, TAN Langlang
    Science & Technology Review. 2014, 32(28/29): 79-84. https://doi.org/10.3981/j.issn.1000-7857.2014.h2.011
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    In a certain underground lead-zinc mine, an urgent task is to decrease the dilution and the loss of the pillar stope mining as much as possible and to mine the pillar mineral resources fully. In order to control the stope complicated boundary, the explicit dynamic analysis software LS-DYNA is used for the numerical simulation optimization of the charging structure of side holes,and the spacings of sides and both ends of pillar stopes. The comparison of the x-direction vibration velocity variances of four interval charging structure plans at the boundary measurement points shows that the blasting vibration is the most uniform by the optimal hole charging structure scheme with the interval proportion of 0.588. The optimal hole spacings of sides and both ends are, respectively, 1.6 m and 1.2m with the minimum destruction of rock and backfill based on the Fourth Strength Theory. Applying the research result to the trial pillar stope, the feasibility of the pillar stope dilution and loss control is verified
  • ZHAO Chenhao, LIU Yonglan, ZHAO Jie
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    This paper proposes a new method for the shortest path planning of UAV coverage searching in irregular regions. First, the mission area was dispersed with rasterisation by using the detection range of airborne sensor, and the path planning problem of area coverage searching was translated into a travelling salesman problem that can be solved. Then, the genetic algorithm was improved by using the multi-group parallel algorithm frame and elitist strategy, and the fitness function of the algorithm was redesigned. The parallel elitist genetic algorithm was put forward to solve the TSP problem. Experimental results show that the proposed method is applicable to the path planning problem of UAV area coverage searching. The proposed PEGA algorithm had a high convergence speed and the optimal solution had satisfactory quality. Improving the fitness function reduced the case of long distance between two points connected, apparently optimizing the path planning results.
  • LI Shaohua, WU Jinyi
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    A fuzzy-logic controller system is designed for improving the heavy vehicle's yaw stability in this paper. The control objectives of this system are the yaw rate and the body sideslip angle. With the differential braking, a corrective yaw moment is generated to improve the vehicle's yaw stability significantly. A vehicle virtual prototype model is established with the application of the Adams/Car. A fuzzy controller is designed for the yaw stability control system in the Matlab/Simulink environment and is combined with the vehicle mode1. The vehicle responses at various running speeds, brake decelerations, road frictional coefficients and road curve radii are analyzed by co-simulations. The results show that the proposed differential braking fuzzy controller can reduce the yaw rate, the body sideslip angle and the lateral acceleration noticeably and thus improve the vehicle's yaw stability effectively. With the increase of the brake deceleration and the road curve radius, the control effect is enhanced. Even on a low frictional coefficient road, the controller can also have an excellent performance in reducing the danger of the vehicle going out of control.
  • Reviews
  • SHE Maoyun, YIN Guixiang, DU Lipu, ZHANG Pingzhi, YE Xingguo
    journal1. 2014, 32(28/29): 97-103. https://doi.org/10.3981/j.issn.1000-7857.2014.28/29.014
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    Plant regeneration performance during tissue culture in vitro is affected by many factors. To improve plant regeneration efficiency, the previous strategies focused on genotype screening, optimization on media components, and combination of plant growth regulators, while paying little attention to the significant impact of environmental stress on plant regeneration. This paper summarizes the recent research progress on different stress-induced effects on plant regeneration during tissue culture in vitro, including oxidative stress, osmotic stress, wounding, and cold stress. The oxidative stress plays a dual role in the plant regeneration process, i.e., induction of relevant stress antioxidant enzymes synthesis contributing to plant regeneration positively and changes on cell membrane permeability caused by oxidative stress leading to cell death negatively. The short-term osmotic stress significantly promotes the plant regeneration potential. Wounding has a positive effect on somatic embryogenesis by activating the relevant gene expression. The effect of temperature on the development of plant embryonic cells depends on the plant developmental stage and treatment intensity, and moderate temperature pretreatment can induce more embryonic calli. Therefore, appropriate stress pretreatment on explants used for tissue culture may contribute to the formation of embryogenic calli greatly, and may ultimately help to improve plant regeneration capacity during tissue culture in vitro.
  • JI Jianghui, YU Liangliang
    journal1. 2014, 32(28/29): 104-108. https://doi.org/10.3981/j.issn.1000-7857.2014.28/29.015
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    In this work, we review two kinds of thermophysical models widely adopted in the thermophysical investigations of asteroids, i.e., TPM and ATPM, and further discuss their scientific applications and applicable scopes in the investigations. In general, TPM can be used to derive thermal inertia of the asteroid, whereas ATPM can not only be applied to the of thermophysical characteristics of the asteroids such as thermal inertia, surface roughness, etc., but also reveal the YORP effect of asteroids. It is shown that TPM and ATPM are applicable to effective exploration of the asteroids'thermophysical properties in terms of present observation accuracy. The likely engineering application for future asteroid missions is also briefly discussed.
  • WANG Haochen, LU Feng, WU Jilei, ZHENG Xiaoying
    journal1. 2014, 32(28/29): 109-116. https://doi.org/10.3981/j.issn.1000-7857.2014.28/29.016
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    This paper reviews the studies of features of climate change in China, as well as direct or indirect effects of climate change on population health, to highlight the changes in the incidence rate and spread of communicable diseases, and the direct impacts of temperature change on the morbidity and mortality rate of non-communicable diseases and on vulnerable groups like children and the elderly. The paper also introduces indirect effects of environmental change and crop yields on population health. As temperature rises, the incidence rate and spatial and temporal scales of communicable diseases increase. Heat wave or cold spell will increase the morbidity and mortality of different types of non-communicable diseases and cause negative impacts. Children, the elderly and other valnerable groups have a lower resistance to extreme weather, thus are prone to negative health effects when facing climate change. Climate change causes negative impacts on air, water and soil, which could bring harm to human health. Crop yield has a large fluctuation during the period of climate change, which needs more attention to study its impact on population nutritional intake. Finally, suggestions for further research in this field are provided, including health impacts besides diseases, research objects in different social and economic status, and impacts of urbanization from the perspective of research direction, and strengthening the empirical research, cross-disciplinary construction and strengthening study on theories and methods of intervention from the perspective of methodology.
  • Focus
  • REN Shengli, NING Bi, CHENG Weihong
    journal1. 2014, 32(28/29): 117-124. https://doi.org/10.3981/j.issn.1000-7857.2014.28/29.017
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    Based on the 2013-edition Journal Citation Report (JCR) issued by Thomson Reuters, we analyzed the main bibliometric indexes of the 165 SCI-covered journals published in Mainland China and Hong Kong Area. Compared with the data of 2012-edition JCR, the average total citation and average impact factor are increased by 17.7% and 10.8%, respectively, which are significantly higher than the corresponding values (8.0% and 3.5%) of the 8474 journals included in JCR. Of the 165 journals, there are 13 and 5 journals in the first quartile (Q1) and top 10% of impact factor partitions, respectively, showing some Chinese SCI journals have relatively higher impact in certain disciplines. We also made a comparative analysis between the 67 journals supported by the project "Plan of Promoting International Influence for Chinese Scientific Journals" and the 83 journals which are not supported by this project.