Collect | Home Page 
   
Office Online  
Journal Online
· Forthcoming Articles
· Current Issue
· Archive
· Advanced Search
· View by Fields
· Archive By Subject
· Special Issues
· Download Articles
· Read Articles
· Email Alert
· Recommended
Links
·
·
·
·
·
·
·
·
·
·
·
   Science & Technology Review
2015, Vol.33, No. 2
28 January 2015


Select | Export to EndNote

Hot!

Science & Technology Review. 2015, 33 (2): 4-4.
Full text: HTML (122 KB)  PDF  (1210 KB)  ( 89 )
Abstract ( 254 )

Science & Technology Review. 2015, 33 (2): 1-2.
Full text: HTML (41 KB)  PDF  (398 KB)  ( 130 )
Abstract ( 233 )

Top advances of science, technology and engineering from China in 2014

CHEN Guangren, WU Xiaoli, LIU Zhiyuan, TIAN Tian, SU Qing, SHI Yongchao
Science & Technology Review. 2015, 33 (2): 14-27. ;  doi: 10.3981/j.issn.1000-7857.2015.02.001
Full text: HTML (802 KB)  PDF  (8011 KB)  ( 278 )
Abstract ( 1047 )
Based on the event every year for selecting the annual top advances in science, technology and engineering held by Science & Technology Review, top 10 scientific achievements, top 10 technological achievements and top 10 engineering achievements from China in 2014 during January 1 to December 31, are selected respectively from a lot of scientific researchespublished in influential academic journals and scientific newspapers. The selection procedure involved screening and recommending candidate internally, followed by appraisal from experts including editorial board members and external reviewers. These achievements are introduced as the time sequence of publishing.

Spatial-temporal characteristics of coastline in Jiaozhou Bay during the period of 1944-2012

WU Ting, HOU Xiyong
Science & Technology Review. 2015, 33 (2): 28-34. ;  doi: 10.3981/j.issn.1000-7857.2015.02.002
Full text: HTML (1 KB)  PDF  (4758 KB)  ( 674 )
Abstract ( 416 )
In order to depict the overall trend and the spatio-temporal characteristics of coastline changes of Jiaozhou Bay, the coastlines of Jiaozhou Bay in 1944, 1954, 1986, 2001, 2006, 2009 and 2012, respectively, are extracted from topographic maps and remote sensing imageries, and the end point rate, the average rate, the weighted linear regression rate are then calculated based on transects. The results are as follows: 1) The end point rate and the weighted linear regression rate can equally detect the spatiotemporal characteristics of coastline changes in Jiaozhou Bay during 1944-2012, nevertheless, the latter, with regard to the confidence interval and the correlation coefficient, is more reliable; 2) During the period of 1944-2012, the coastline of Jiaozhou Bay shows a prevailing trend of advancing seaward. Segments in the east of Baisha River are straightened and have an advancing trend but with a small magnitude; Segments near the Baisha River, Dagu River and Yang River advance in the form of the salt pan and the aquaculture pond expansion; Afterwards the coastline shifts to the seaward edge of Huangdao after it becomes a land-tied island, segments near Huangdao advances seaward in the form of the reclamation due to the vigorous development of the harbor and the harbor industry, and consequently becomes the hotspots of the coastline expansion in Jiaozhou Bay during nearly the past 30 years; 3) Coastline changes of Jiaozhou Bay see remarkable periodical characteristics, and it is shown that the eco-social development is the main driven factor of the coastal zone change: At the beginning of the New China, the construction and the expansion of salt fields are the predominant mode of coastline change, and during the period of 1980s to 1990s, both the extent and the expansion rate of aquaculture exceed the salt industry, and then, in the 21st century, the coastline development driven by the construction of harbor and harbor industry becomes the primary mode. This study provides a comprehensive understanding of the coastal utilization history of Jiaozhou Bay and its impacts on eco- environmental system, which could be used in the scientific planning and the integrated management of the coastal zone.

Bioinformatic analysis of SH2D7 and its encoded protein

YANG Hua, YANG Fengqin, LIAO Guoling, LIU Xueying
Science & Technology Review. 2015, 33 (2): 35-38. ;  doi: 10.3981/j.issn.1000-7857.2015.02.003
Full text: HTML (1 KB)  PDF  (1748 KB)  ( 405 )
Abstract ( 226 )
The bioinformatic software is used to predict the nucleotide sequence of SH2D7 and the second structure of its encoding protein. It is shown that SH2D7 is located on the human chromosome 15q25.1, containing six exons and five introns. SH2D7 protein is mainly involved in the regulation of the gene expression and the signal transduction. Its molecular weight is 49.8 kD and the isoelectric point is 5.99. SH2D7 is a hydrophilic protein mainly located in the nucleus and there are 35 phosphorylation sites and 22 epitopes bit in the SH2D7 protein sequence.

Hardware design and implementation of GPS data acquisition system for track inspection

FU Qinyi, LIU Zhiping, JIA Yan
Science & Technology Review. 2015, 33 (2): 39-44. ;  doi: 10.3981/j.issn.1000-7857.2015.02.004
Full text: HTML (1 KB)  PDF  (3967 KB)  ( 576 )
Abstract ( 263 )
Owing to the low efficiency and the high cost of the traditional track inspection system, a new track inspection system is designed on the basis of the GPS global positioning technology and the GPRS wireless communication technology. Four primary modules of the hardware of the GPS data acquisition system are designed and explained in detail, including the GPS data acquisition module, the GPRS communication module, the single-chip microcomputer minimum system and the power transition module. The GPS data acquisition module consists of four GPS modules in the base station and a GPS node in the moving station that realizes the unity of the relative and absolute measurements and improves the positioning accuracy. It is shown that the GPS data acquisition operates in real-time and is accurate, and the data update rate is as high as 50 Hz; The application of the GPRS communication module makes the data transmission convenient and quick; The data are firstly cached in the flash storage, are uploaded to the upper computer for storage and processing afterwards, the system capacity is up to 500 G, the data processing is simple and efficient.

Simulation of helicopter blade characteristics based on multi-body dynamics

HE Jilin, TAN Yao, MA Yunrong, XU Lei
Science & Technology Review. 2015, 33 (2): 45-48. ;  doi: 10.3981/j.issn.1000-7857.2015.02.005
Full text: HTML (1 KB)  PDF  (2149 KB)  ( 673 )
Abstract ( 285 )
In view of the actual demand in upgrading performance improvements for unmanned aerial vehicle blade, the 200 kg unmanned aerial vehicle rotor is used as the prototype model, and with the COMOSOL software, the characteristics of helicopter blades are simulated. The mathematical model of the blade lift is based on the blade element approach, to overcome aerodynamic loading headaches in the conventional rotor dynamics simulation analysis. The blade attack angle and lift, and the tip displacement against the total distance and the cycle variable pitch are obtained through the coupling relationship between the space rotation movement of the helicopter rotor blade and the elastic deformation, and the results are compared with those of the conventional numerical analysis. The accuracy of the simulation results is verified. According to the simulation results, specific suggestions for improvement of the blade angle, the blade leading edge stiffness etc. are made, that provides a reference for improving the design of the blade.

Numerical simulation of transient flow performance during starting and stopping processes in centrifugal pump by varied-speed method

HUANG Si, ZHANG Jie, ZHANG Xuejiao, OU Guowei
Science & Technology Review. 2015, 33 (2): 49-53. ;  doi: 10.3981/j.issn.1000-7857.2015.02.006
Full text: HTML (1 KB)  PDF  (3346 KB)  ( 247 )
Abstract ( 254 )
The starting and stopping processes of a centrifugal pump are essentially transient processes, where the hydraulic performance changes with the rotational speed of the pump. In this paper, the CFD simulation is made by changing the impeller rotational speed over time for the type IS125 centrifugal pump to study the transient internal flow field and the external performance of the pump during starting and stopping processes. The entire simulation consists of four stages, including the startup, the normal running, the stopping and post-stopping of the pump. The variations of the flow field are obtained from the transient simulation. The flow-rate, the head and other external performance parameters against time are also obtained, which can be used in pump designs and actual operations.

Main controlling factors in hydrocarbon accumulation of lower Sha 3 in Yingzijie area of Linnan Sag

FENG Dongxiao
Science & Technology Review. 2015, 33 (2): 54-58. ;  doi: 10.3981/j.issn.1000-7857.2015.02.007
Full text: HTML (1 KB)  PDF  (3956 KB)  ( 145 )
Abstract ( 283 )
Although Yingzijie area is near the hydrocarbon generation center, because of its simple structure and the lack of structural traps, traditionally, the exploration potential is considered not great. In order to overcome the exploration obstacles, the sedimentary evolution and the facies types are studied in this paper. Based on the dominant sand-body types, the hydrocarbon source rock pressure and the subtle traps, the main controlling factors in the hydrocarbon accumulation of lower Sha 3 in Yingzijie area are analyzed. It is shown that there are two kinds of dominant sand-bodies: The sheet sand and the turbidite fan sand. These sand-bodies are surrounded by the source rock with the reservoir types being subtle lithologic, where the hydrocarbon accumulation factors are controlled by the overpressure of the source rock and the effective reservoirs. The oil fullness degree of the reservoirs are controlled by the overpressure of the source rock and the oil scale is controlled by the effective reservoirs in the region of the overpressure of the source rock, and the accumulation model can thus be built, as the self-source and the self-reservoir and the overpressure controlling accumulation.

Fuzzy comprehensive evaluation model for early warning of production running in water flooding oilfield during high water-cut period

XIAO Wu, JIANG Hanqiao, FANG Wenchao, LI Junjian
Science & Technology Review. 2015, 33 (2): 59-63. ;  doi: 10.3981/j.issn.1000-7857.2015.02.008
Full text: HTML (1 KB)  PDF  (1643 KB)  ( 145 )
Abstract ( 307 )
Maintaining stable production is difficult for a water flooding oilfield during the high water-cut period, which usually brings about losses to the oilfield company due to the abnormal fluctuation of production. In order to provide a basis for the adjustment strategy, making oilfields more risk- resistant, a 2- level fuzzy comprehensive evaluation model for early warning of production running is established. The model includes dual functions: The early warnings in production composition and production integration. Ten significant indexes influencing the production are chosen related with the production composition, the reservoir energy complement and the management; Meanwhile the influences of these indexes are analyzed. Index weight vector is calculated by using the production data, and the membership matrix is maintained by using the (0,1) membership degree method. The established model is validated through historical production data of A and B oil extraction factories in Shengli Oilfield. It is shown that the early warning for situations of production's abnormal decrease is accurate. The model also provides a risk reference from probabilistic prospective. Besides, the early warning in production composition can help analyze the production's abnormal decrease to determine the direction of the production adjustment.

Flow of hydrate slurry in a horizontal elbow pipe

JIANG Guoye, WANG Xiaoya
Science & Technology Review. 2015, 33 (2): 64-68. ;  doi: 10.3981/j.issn.1000-7857.2015.02.009
Full text: HTML (1 KB)  PDF  (1779 KB)  ( 344 )
Abstract ( 127 )
In order to study the flow characteristics of hydrate slurry, two-fluid Euler models based on the kinetic theory of the granular flow are established, in which the RNG k-ε model is used to simulate the turbulence movement and the drag force is used to express the interaction between the liquid phase and the solid phase. It is shown that secondary flows can clearly seen to arise in the elbow, and the maximum velocity occurs close to the inner side of the cross section; the hydrate slurry's turbulence kinetic energy in the 90° elbow is enhanced and the kinetic energy distribution is homogenized because of the hydrate particles; the presence of the elbow pipe and hydrates has a remarkable effect on the pressure energy losses. It is also shown that the pressure gradient of the hydrate slurry increases with its average velocity rising at the same hydrate's volume fraction, and that the pressure gradient of the hydrate slurry sees a slowly-growing zone, a transient zone and a rapidly-growing zone in turns with hydrate's volume fraction rising at the same velocity. The pressure gradient zoning and rheology diversity as well as the hydrate volume fraction have to be investigated from the point of microcosmic characteristics changes in hydrate's growth to early predict the pipeline plug risk.

Influence of effective stress on permeability of different rank coals

XUE Pei, ZHENG Peiyu, XU Wenjun, REN Xiaolong, HUANG Chen, DU Jiangmin
Science & Technology Review. 2015, 33 (2): 69-73. ;  doi: 10.3981/j.issn.1000-7857.2015.02.010
Full text: HTML (1 KB)  PDF  (1552 KB)  ( 155 )
Abstract ( 387 )
Based on the stress sensitivity experiments of various rank coals, the influence of the effective stress on the permeability of different rank coals is studied. It is shown that in the same range of the effective stress variation, the decrease of the low-rank coal permeability is larger than that of the medium-rank and high-rank coals; The permeability variations of the low-rank and high-rank coals more consistently follow an exponential law than the medium-rank coal; In the low effective stress range, the damage coefficient of the permeability and the stress sensitive coefficient of the low-rank coal are greater than those of the medium-rank and high-rank coals; Under the identical effective stress, the cleat compressibility of the low-rank coal is greater than that of the medium-rank and high-rank coals; The cleat compressibility decreases with the increase of the effective stress, and it is not constant. Fitting results of evaluation parameters of the stress sensitivity show that the damage coefficient of the permeability and the cleat comperssibility of the low-rank and medium-rank coals follow an exponential law, but for the high-rank coal, they follow a linear function; the stress sensitive coefficient of various rank coals follows an exponential law.

Effect of coal seam gas seepage on gas pressure distribution

YUE Gaowei, YUE Jiwei, XU Mengfei
Science & Technology Review. 2015, 33 (2): 74-79. ;  doi: 10.3981/j.issn.1000-7857.2015.02.011
Full text: HTML (1 KB)  PDF  (3426 KB)  ( 230 )
Abstract ( 334 )
Many experiments indicate that for the gas seepage in the porous media, not only the threshold pressure gradient is important, but also the slippage effects should be considered. Based on the characteristics of the gas seepage in coal seams, a nonlinear seepage mathematical model through the coal seam is built, with consideration of the threshold pressure gradient and the slippage effects, to numerically simulate the gas pressure distribution in the process of the coal seam gas seepage. It is shown that the slippage has a larger effect on the gas pressure in a certain coal seam depth, and with the increase of the depth and the passing of the time, the difference gets more obvious. The change of the slip factor b directly affects the gas pressure distribution in the coal seam, and with the increase of the slip factor, the gas pressure reduces and the slippage gets more obvious. As compared with the case without considering the slippage effect (the Darcy solution), the gas pressure distribution curves in the coal seam, with considering the slippage effect, are closer to the measured data, as is consistent to the actual gas seepage, which indicates that the slippage effect is very important in the process of the coal seam gas seepage. Some internal structural characteristics and the slippage flow mechanism in the coal seam are revealed, which will help for the theoretical prediction of the lane coal seam emission's width and for the coalbed methane industrialization in hypotonic reservoirs.

Constant pressure water-supplying system based on fuzzy PID for dust-reducing spray at fully mechanized coalface

ZHANG Qiang, LI Hongfeng, WANG Haijian, QI Xiu
Science & Technology Review. 2015, 33 (2): 80-85. ;  doi: 10.3981/j.issn.1000-7857.2015.02.012
Full text: HTML (1 KB)  PDF  (2922 KB)  ( 165 )
Abstract ( 264 )
This paper proposes a strategy of fuzzy PID control for constant pressure water-supplying system to reduce the dust by spray at fully mechanized coalface. Simulation analysis of the system was carried out under different working conditions using SIMULINK software. The simulation results show that the time for the system to reach a stable value using fuzzy PID control was 5 s shorter than that using fuzzy PID control, and the speed for the system to restore stability after disturbance was 36% higher than that using PID control, and the former had no major overshoot phenomenon. The proposed strategy improved the static and dynamic performance of the system, thus met the requirement of constant pressure water-supplying system for dust-reducing spray at fully mechanized coalface, demonstrating its feasibility.

Application of FFT spectrum analysis to identify microseismic signals

JIANG Wenwu, YANG Zuolin, XIE Jianmin, LI Jiafu
Science & Technology Review. 2015, 33 (2): 86-90. ;  doi: 10.3981/j.issn.1000-7857.2015.02.013
Full text: HTML (1 KB)  PDF  (2561 KB)  ( 354 )
Abstract ( 318 )
To identify large scale stopping blasting and large magnitude micro-seismic signals, the FFT spectral analysis method is used. The analysis of the stopping blasting and macro-scale rock fracture signals is made through power spectrum and magnitudefrequency characteristics. The distribution difference of the energy on the frequency brand can be revealed. It is shown that in the frequency brand distribution of the large magnitude micro-seismic signal, the amplitude value takes the maximum at about 10 Hz and 30~50 Hz. The large scale stopping blasting is in a narrow frequency brand. Its amplitude value is higher than the normal signal. It reaches the top amplitude at 10 Hz. From the energy distribution, the energy distribution of the blasting signal mostly in the 0-30 Hz low frequency area. It is because the blasting is always accompanied with an enormous energy, which is released very fast. The microseismic energy is distributed mostly in the range of 30-50 Hz. So for the two kinds of signal identifications, two kinds of signal spectrum characteristics may be used.

Research progress on molecular mechanism of plant regeneration from cultured tissues via organogenesis

SHE Maoyun, YIN Guixiang, ZHAO Pei, DU Lipu, ZHANG Pingzhi, YE Xingguo
Science & Technology Review. 2015, 33 (2): 91-98. ;  doi: 10.3981/j.issn.1000-7857.2015.02.014
Full text: HTML (1 KB)  PDF  (1488 KB)  ( 595 )
Abstract ( 494 )
The progress of plant regeneration in vitro in molecular level is reviewed in this paper, including the main stages of plant tissue culture of explants, the molecular mechanisms of dedifferentiation of differentiated tissues, shoot regeneration and root regeneration, as well as the cytogenetic basis of regeneration traits in cereal crops. It is summarized that the limitation of plant genotypes with high and stable regeneration performance, shortage of cloned key genes associated with regeneration traits, and weak function of identified genes related to somatic embryogenesis in other plants are the main problems in the investigation of plant regeneration in molecular biology. In future the identification or development of the plant genotypes with desirable regeneration ability should be stressed by using various strategies to expand the gene resource for the exploration of the corresponding phenotype. The aim of this review is to deepen the awareness of the importance of molecular investigation in plant regeneration, and to boost the characterization of more plant regeneration-relevant genes for the further understanding of molecular mechanism of underlying plant organogenesis during plant tissue culture in vitro and the development of plant genetic engineering breeding.

Progress in regenerative cryocoolers

HU Jianying, LUO Ercang
Science & Technology Review. 2015, 33 (2): 99-107. ;  doi: 10.3981/j.issn.1000-7857.2015.02.015
Full text: HTML (1 KB)  PDF  (3290 KB)  ( 583 )
Abstract ( 276 )
Many physical phenomena are accompanied with low temperature. Cryogenic technologies have been applied in many fields. Regenerative cryocooler is one of the two mainstream cryocoolers. It mainly includes three configurations: Stirling cryocooler, GM cryocooler and pulse tube cryocooler. The first two configurations have been well studied. Their disadvantages are short lifetime or low efficiency. Pulse tube cryocooler possesses high reliability and high efficiency, and has attracted much attention. Thermoacoustic theory explains the working mechanism of regenerative cryocoolers from the viewpoint of interactions between the pressure wave and solid surface, gradually becoming a universal theoretical tool for regenerative refrigerators. It also gave birth to thermoacoustic cryocoolers. The so-called double-acting thermoacoustic cryocooler possesses high efficiency and high reliability. It may be a good choice for future applications. Now, quite a few hotspots have arisen in the study of regenerative cryocoolers. Various research has been carried out in this field in the hope of improving the configuration and expanding the applications of regenerative cryocoolers.

Empirical mode decomposition and analysis of its evaluation criteria

GAO Jing, DENG Jiahao
Science & Technology Review. 2015, 33 (2): 108-112. ;  doi: 10.3981/j.issn.1000-7857.2015.02.016
Full text: HTML (1 KB)  PDF  (612 KB)  ( 18881 )
Abstract ( 235 )
The empirical mode decomposition (EMD), that provides a multi-scale and highly adaptable method, scores a breakthrough in the signal processing field. This paper gives a brief review of research advances of the theoretical foundation of the EMD algorithm based on the concept of the EMD. Furthermore, a comparison of various improved EMD methods is made. The applications of the EMD and the directions for further research are discussed.

Status quo, problems and reasons of science popularization in universities: A micro-political analysis

ZHAI Jiequan, REN Fujun
Science & Technology Review. 2015, 33 (2): 113-119. ;  doi: 10.3981/j.issn.1000-7857.2015.02.017
Full text: HTML (87 KB)  PDF  (861 KB)  ( 112 )
Abstract ( 589 )
This paper analyzes the attitude of university leaders and teachers towards science popularization from a micro-political perspective. Universities have abundant scientific and technological resources, research facilities and human resources. Therefore, they possess advantages and play an important role in science popularization. In recent years, all sectors of society and universities themselves attach importance to science popularization in universities, while its development is unsatisfactory with many problems demanding prompt solution. The reasons are complicated. From the micro-political perspective, the evaluation system inside and outside universities has immediate impact on the attitude of university leaders and teachers towards science popularization, which is the main cause for the problems.

Science & Technology Review. 2015, 33 (2): 8-8.
Full text: HTML (36 KB)  PDF  (347 KB)  ( 454 )
Abstract ( 411 )

Science & Technology Review. 2015, 33 (2): 10-10.
Full text: HTML (36 KB)  PDF  (348 KB)  ( 153 )
Abstract ( 391 )

Science & Technology Review. 2015, 33 (2): 13-13.
Full text: HTML (36 KB)  PDF  (352 KB)  ( 160 )
Abstract ( 779 )

Science & Technology Review. 2015, 33 (2): 122-122.
Full text: HTML (84 KB)  PDF  (826 KB)  ( 119 )
Abstract ( 427 )

Science & Technology Review. 2015, 33 (2): 123-123.
Full text: HTML (54 KB)  PDF  (534 KB)  ( 75 )
Abstract ( 477 )

Science & Technology Review. 2015, 33 (2): 125-125.
Full text: HTML (73 KB)  PDF  (720 KB)  ( 74 )
Abstract ( 190 )

Science & Technology Review. 2015, 33 (2): 126-126.
Full text: HTML (70 KB)  PDF  (691 KB)  ( 106 )
Abstract ( 516 )

Science & Technology Review. 2015, 33 (2): 127-127.
Full text: HTML (38 KB)  PDF  (366 KB)  ( 226 )
Abstract ( 707 )

Science & Technology Review. 2015, 33 (2): 127-127.
Full text: HTML (38 KB)  PDF  (366 KB)  ( 155 )
Abstract ( 695 )

Science & Technology Review. 2015, 33 (2): 7-7.
Full text: HTML (104 KB)  PDF  (1025 KB)  ( 53 )
Abstract ( 353 )

Science & Technology Review. 2015, 33 (2): 9-9.
Full text: HTML (80 KB)  PDF  (791 KB)  ( 48 )
Abstract ( 263 )

Science & Technology Review. 2015, 33 (2): 11-11.
Full text: HTML (71 KB)  PDF  (699 KB)  ( 67 )
Abstract ( 444 )

Science & Technology Review. 2015, 33 (2): 120-120.
Full text: HTML (67 KB)  PDF  (657 KB)  ( 131 )
Abstract ( 756 )

Science & Technology Review. 2015, 33 (2): 121-121.
Full text: HTML (79 KB)  PDF  (780 KB)  ( 160 )
Abstract ( 619 )

Science & Technology Review. 2015, 33 (2): 124-124.
Full text: HTML (72 KB)  PDF  (708 KB)  ( 200 )
Abstract ( 301 )

Science & Technology Review. 2015, 33 (2): 128-128.
Full text: HTML (147 KB)  PDF  (1457 KB)  ( 188 )
Abstract ( 823 )

Copyright © Editorial office of Science & Technology Review
Tel: +86-10-62138113 Fax: +86-10-62138113 E-mail: jdbbjb@cast.org.cn
京ICP备14028469号-1