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   Science & Technology Review
2013, Vol.31, No. 34
08 December 2013

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卷首语

Science & Technology Review. 2013, 31 (34): 3-3. ;  doi:
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Abstract ( 86 )
科技风云

Science & Technology Review. 2013, 31 (34): 7-7. ;  doi:
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特别栏目

Science & Technology Review. 2013, 31 (34): 8-8. ;  doi:
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Science & Technology Review. 2013, 31 (34): 8-8. ;  doi:
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Science & Technology Review. 2013, 31 (34): 10-10. ;  doi:
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Science & Technology Review. 2013, 31 (34): 11-11. ;  doi:
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Science & Technology Review. 2013, 31 (34): 12-12. ;  doi:
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Science & Technology Review. 2013, 31 (34): 14-14. ;  doi:
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Science & Technology Review. 2013, 31 (34): 81-81. ;  doi:
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Science & Technology Review. 2013, 31 (34): 82-82. ;  doi:
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Science & Technology Review. 2013, 31 (34): 82-82. ;  doi:
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Science & Technology Review. 2013, 31 (34): 86-88. ;  doi:
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Science & Technology Review. 2013, 31 (34): 89-89. ;  doi:
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Science & Technology Review. 2013, 31 (34): 90-92. ;  doi:
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Science & Technology Review. 2013, 31 (34): 94-94. ;  doi:
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Science & Technology Review. 2013, 31 (34): 95-95. ;  doi:
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Science & Technology Review. 2013, 31 (34): 96-96. ;  doi:
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科技事件

Science & Technology Review. 2013, 31 (34): 9-9. ;  doi:
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Abstract ( 68 )
Exclusive

Probing the Origin of Masses and the 2013 Nobel Prize in Physics

KUANG Yuping;HE Hongjian
Science & Technology Review. 2013, 31 (34): 15-17. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.001
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Abstract ( 172 )
We first briefly review the Higgs mechanism proposed in 1964 by Peter Higgs and Francois Englert et al. together with its important role in the construction of the electroweak standard model, showing why the 2013 Nobel Prize in Physics is awarded to Englert and Higgs after the discovery of a Higgs resonance in 2012. We then point out that it is important to probe how this Higgs boson may deviate from the standard model prediction, and discover the possible new physics. The LHC upgrades and future high energy colliders are crucial for this goal. Finally we review the perspectives of particle physics.

Computer Simulation of Complex Systems:the 2013 Nobel Prize in Chemistry

HU Hao
Science & Technology Review. 2013, 31 (34): 18-21. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.002
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Abstract ( 409 )
The 2013 Nobel Prize in Chemistry is awarded to three scientists (Martin Karplus, Michael Levitt and Arieh Warshel) for the dvelopment of multiscale models of complex chemical systems. Their work is based on the development of theoretical and computational chemistry, and the 2013 Nobel Prize in Chemistry is awarded to theoretical chemistry worker has special significance. In this paper, we discuss their works in detail.

Mechanism of Vesicle Traffic:Commentary on the 2013 Nobel Prize in Physiology or Medicine

ZHANG Chen;ZHOU Zhuan
Science & Technology Review. 2013, 31 (34): 22-23. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.003
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Abstract ( 223 )
The 2013 Nobel Prize in Physiology or Medicine honours three scientists (Randy Schekman, James Rothman and Thomas SÜdhof) who have solved the mystery of how the cell organizes its transport system. Here we brifely introduce their work on the vesicle traffic, and how their findings expand our understandings of nature.
Articles

A Method of Soft Object Collision Detection Based on Spherical and Distance Fields

FANG Yanhong;WU Bin;YANG Zhengyi
Science & Technology Review. 2013, 31 (34): 24-28. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.004
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Abstract ( 172 )
This paper presents a novel method of real-time collision detection in virtual environments based on spherical harmonics and distance fields. Fundamentals of spherical harmonics modeling virtual object are initially proposed for representing complex objects with different degrees of spherical harmonics in the spherical coordinate system. Distances between virtual objects and space mesh are then projected onto the spherical surface to generate a distance map. Approximate collision detection is performed at the low scale, while accurate detection is performed at the high scale. Experimental results show that computational complexities and memory requirements are reduced significantly compared with those encountered in, for example, SQ-map method and the adaptive distance field, due to the fact that in this case the bounding sphere and the virtual object represented by spherical harmonics are in the same spherical reference system.

Design and Algorithm of Ballistic Trajectory Simulation System of Antiaircraft Gun

XUE Qing;QIN Li;LIU Minxia;WU Xiangdong
Science & Technology Review. 2013, 31 (34): 29-33. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.005
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Abstract ( 246 )
The system that displays and controls antiaircraft gun projectile flight characteristics uses data from host computers to realize 3D ballistic trajectory simulation, then compares the results with ideal ballistic trajectories in order to judge whether the accuracy of ballistic trajectory satisfies the requirements and to evaluate whether the firepower technology achieves the expected results. This paper briefly introduces the basic framework and functions of the system and presents a cubic spline interpolation fitting algorithm for 3D ballistic trajectory simulation. The algorithm decomposes the 3D discrete characteristic data into two 2D trajectories separately in the launch plane and the horizontal plane, then interpolates and fits them by a piecewise cubic spline interpolation algorithm respectively, and finally plots the 3D ballistic trajectory according to the interpolation results. The algorithm is realized by Microsoft Visual C++ 6.0. Through an evaluation instance, the 3D ballistic trajectory is shown to be smooth and can pass through each characteristic point, meeting the fitting condition as well as the requirement of trajectory simulation.

Prediction of Backfill Drill-hole Life Based on Combined Model of GA-SVM and Neural Network

ZHANG Qinli;CHENG Jian;CHEN Qiusong;HU Wei;ZHOU Bihui
Science & Technology Review. 2013, 31 (34): 34-38. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.006
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Abstract ( 249 )
The backfill of a drill-hole is a throat engineering process in which the filling slurry is transported to the underground stope from the surface to ensure the safety of the mine normal operation. To predict the service life of the mine backfill drill-hole, a combination forecasting model of the Support Vector Machine (SVM) and the BP neural network is established in this paper. The mean square error of the value is taken as a fitness function of the SVM. Then, the SVM model parameters are optimized through the Genetic Algorithm(GA). Then, the optimized SVM is applied to predict the prediction set. The final forecast result is obtained by means of the revision of the residual error through the BP neural network. A certain mine is taken as an example, its drill-hole life is predicted through the combination forecasting model, and the optimal parameters are obtained. The adaptive value (mean square error mse) is 0.0111; the penalty coefficient C is 47.0768; the kernel function parameter σ is 2.2638. The accuracy of the model is analyzed. The relative error of the predicted results is about 3%. Compared with the single prediction model, the combination forecasting model enjoys a higher accuracy.

Dynamic Modification of Super Short Term Numerical Wind Forecast Based on Neural Networks at Wind Farm

WU Xi;WANG Binbin;ZHOU Hai;YU Jiang;CUI Fang
Science & Technology Review. 2013, 31 (34): 39-44. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.007
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Abstract ( 217 )
For effective planning and scheduling and for Wind Power Prediction (WPP) at 70 meters above the ground and 0-4h super short term wind speed forecasting, this paper uses the NWP wind speed of MM5 grids from the National Meteorological Center to analyze the prediction error at the wind tower height in a wind farm which is located off the coast. Based on the meteorological data from the wind tower and after data statistical analysis, it is found that the numerical forecast wind speed errors have correlations with themselves and the prediction errors are caused by the elements of sustainability. A method using earlier observation errors and turbulent index to revise the wind speed forecasting of MM5 is discussed and an ANN dynamic modification model for super short term forecasting is set up. The results show that after correction of the forecast wind speed, the mean absolute error is reduced and the prediction accuracy is improved effectively. It is also shown that the error index decreases about 40%, and the prediction curve can better reflect the high frequency of wind speed fluctuations, which better agrees with the measured wind speed curve. Update can be done once every four hours, satisfying the requirements of power grid dispatching. The method is simple and economic and can be used widely in small and medium-sized wind farms. It will help effective use of wind power as well as safe operation of power companies.

Petrological Characteristics and Sedimentary Environment of the Middle Ordovician Lashizhong Formation at Zhuozishan Area, Inner Mongolia Autonomous Region

XIAO Bin;HE Youbin;LUO Jinxiong;YUAN Bochao
Science & Technology Review. 2013, 31 (34): 45-51. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.008
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Abstract ( 367 )
The middle Ordocivian Lashizhong Formation in Zhuozishan area contains mainly dark-gray shale, grayish-green sandstone, siltstone and taupe-gray conglomerate, which could be divided into three members. Based on an analysis of the lithologic character, sedimentary structure, palaeobiologic fossils and geochemical indicators, it is believed that the sedimentary environment of Lashizhong Formation is a deep-water slope to basin margin environment. The results of sedimentary facies analysis show that the slope facies and basin margin facies are main depositional facies in the study area, which can be further divided into two subfacies: the upper slope and lower of slope sediments, and three microfacies: proximal channel, distal channel and levee sediments. The litho-section on the whole covers a complete sedimentation cycle of marine transgression and marine ingression.

Production Decline Laws for Vertical Fracture Well in Low-permeability Oil Reservoirs

XIONG Jian;DAN Tao;CHEN Qing;ZHOU Cheng
Science & Technology Review. 2013, 31 (34): 52-55. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.009
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Abstract ( 231 )
The vertical fracture is asymmetrical about the wellbore or the two wings of the fracture are not certainly in a line for the complex geo-stress in the possession of fracturing of oil gas reservoirs. In view of the low-permeability reservoir after fracturing developing the asymmetrical vertical fractures and non-coplanar fractures, based on the non-steady seepage theory, and using the potential function theory, superimposition principle and numerical analysis method, a dynamical prediction model for the vertical fracture in low-permeability oil reservoirs is deduced with the pressure drop superposition principle. The production decline laws are analyzed with practical cases. The result shows that the production of the vertical fracture well is initially high but soon followed by a sharp decline. Then, the production keeps in a relatively stable state and declines slowly in the middle and later. The fracture asymmetry factor has a little effect on the oil well productivity. The non-coplanar angles have a greater effect on the oil well productivity in the initial stage. The reservoir heterogeneity has a significant effect on the oil well productivity. The longer the fracture length and the bigger the flow conductivity, the higher the oil well production and the faster the decline rate will be. However, the increase amplitude will be getting smaller and smaller with the increasing fracture length and flow conductivity.

Preparing Mullite Powders by Solid-state Reaction Utilizing Waste Silica Fume

TIE Shengnian;WANG Tao;WANG Chang'an
Science & Technology Review. 2013, 31 (34): 56-59. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.010
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Abstract ( 180 )
The mullite powders are prepared through solid-state reaction of manufactured alumina and silica fume in air atmosphere. The influences of calcination temperature and different Al2O3/SiO2 ratios of the amount of substance on the crystalline phases are discussed. The results show that the powder has the maximum mullite content of 95% by K calculating when the Al2O3/SiO2 ratio of the amount of substance and the calcination temperature are 3:2.5 and 1450℃, respectively. On this basis, the relationship between the mullite powders property and the milling time is investigated using particle size distribution analyzer, BET tester and field emission scanning electron microscopy. The average size of mullite powders diminishes with the milling time, with the diameter distribution evolving from unimodal distribution to bimodal distribution. The average size of as-prepared mullite powders is 0.58μm and its BET value is 9.26m2/g. The as-received mullite powders present an irregular shape of polygon.

Effect of Applying Melilotus Officinalis Sligen 1 on Improving Degradated Soil

LI Yuefen;GONG Heyang;LIN Nianfeng;LASOUKANH Viengsouk;ZHAO Yiying
Science & Technology Review. 2013, 31 (34): 60-64. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.011
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Abstract ( 196 )
Soil degradation is a worldwide environment problem, and China is one of the countries with most serious soil degradation problem. The Songnen Plain is a typical area in degenerating, where degradation of different degrees, i.e., desertification, has so far taken place in around 22 percent areas. At present there is no effective method to improve the degenerated soil in such an inmense area. Therefore, Melilotus officinalis Sligen 1 has been introduced from Russia, and the experiments on planting, reproducing, soil improvement, etc. are being conducted all successfully. This article studies the effects of planting Melilotus offcinalia on improving the degraded soil through the analysis of the physical and chemical properties of soil. The results show that planting Melilotus offcinalia can increase organic matter, total N, and hydrolytic N. After planting Melilotus offcinalia, the desalinization rate is very high and total salt content, pH and exchangeable sodium percentage in soil all decrease. In addition, after planting Melilotus offcinalia, selenium and molybdenum in soil present a downward trend. The planting of Melilotus offcinalia can effectively improve the ventilation of soil, and the soil bulk density decreases while total porosity of soil increases. Water content and field capacity both increase, showing that the water-holding capacity increases. In a word, to plant Melilotus officinalis Sligen 1 could enhance the fertility, improve the physical properties, prevent or decrease the loss of water and soil, and offer abundant high quality pastures whose seeds are valuable for economy exploitation.
Reviews

Development Status of Piston Aviation Heavy Oil Engine

PAN Zhongjian;HE Qinghua;YANG Jing
Science & Technology Review. 2013, 31 (34): 65-68. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.012
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Abstract ( 436 )
The development and manufacturing of piston aviation heavy oil engines remains a blank area in China at present, since the aviation gasoline is used in piston engines. The study of the piston aviation heavy oil engine is of great significance to the aviation for both general and military uses. The development stutus of researches abroad is reviewed,the performance parameters of 4 types of advanced engines are compared. The problems of combustion efficiency and control system are the keys of researches in China according to the advanced foreign technology. This review provides a technical reference for the development of the general aviation in our country.

Advances of Green Radical Nitration

SONG Jinhong;ZHOU Zhiming
Science & Technology Review. 2013, 31 (34): 69-74. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.013
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Abstract ( 233 )
The nitration reaction is an important reaction in synthesis of medicine, explosives, dyes, pesticides, and it plays a very important role in organic synthesis. Advances of the new green radical nitration are introduced. The new non-traditional nitric acid nitration systems mainly include two types: NO2+N-hydroxyphthalimide(NHPI) nitration system, and NO2+O3/O2+ inorganic catalyst nitration systems. The development, mechanism and application of the two nitration systems with different nitrating agents are also introduced. Moreover, the mechanism and application of some recent radical nitration reactions are summarized. Green radical nitration is not only environmentally friendly but also has high atom economy and selectivity, offering the possibility of selective nitration of C atoms in heterocyclic compounds. The new green radical nitration is expected to become a valuable trend in the research of nitration.

Progress of Research on Properties and Mechanism of SBL Modified Cement Based Materials

HENG Yanyang;ZHAO Wenjie
Science & Technology Review. 2013, 31 (34): 75-79. ;  doi: 10.3981/j.isnn.1000-7857.2013.34.014
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Abstract ( 304 )
The styrene-butadiene latex (SBL) modified cement based materials have good mobility, water retention, cohesiveness to base material, water tightness, durability, resistance to chemical corrosion, freezing and thawing resistances, good mechanical strength and extension properties. They are low cost and easy to use, therefore, are becoming more widely used. In this paper, the mixed mode and mechanism research on SBL modified cement-based materials are reviewed; the physical and mechanical properties of cement-based materials are introduced for the SBL separate modification, SBL and other latex blending modification, the SBL and fiber modification, and the SBL and admixture modification, respectively. The modified mechanisms of the SBL are discussed from three aspects: the influence of SBL on cement hydration process is due to the interactions of physics and chemistry; the latex particle dispersion and the formation of polymer film are the major cause of the effect of SBL on the microstructure; SBL changes the pore diameter, average pore diameter, pore size distribution, the most probable aperture, and the porosity of the cement based material, increasing the cohesion strength of the material. Finally, the analysis indicates that the SBL modified cement-based materials are cost-effective and environment friendly, and have a long service life and recycling value.
书评

Science & Technology Review. 2013, 31 (34): 80-80. ;  doi:
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Abstract ( 91 )
主编心语

Science & Technology Review. 2013, 31 (34): 83-83. ;  doi:
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Abstract ( 131 )
科技纵横捭阖

Science & Technology Review. 2013, 31 (34): 84-84. ;  doi:
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Abstract ( 61 )
科技职场

Science & Technology Review. 2013, 31 (34): 85-85. ;  doi:
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Abstract ( 101 )

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