Science & Technology Review CONTENTS	Vol.25  No.22  2007 (Sum No. 244)
	This issue published on 25. Nov., 2007
Forward
1  The "973 Program" Gained Great Achievements in Its 10-years History ZHOU Guangzhao
News Round
7  Birth and Death: Permanencies in Science HUANG Yongming
Suggestion
8  Straw-fired Power Generation: Problems and Suggestions
Special to S&T Review
17  The Awards in Science and Technology of the Societies under the China Association for Science and Technology CHEN Guangren, QI Zhihong, ZHU Yu, et al.
Articles
22  Bifurcations and Analyses of Route to Chaos of Mathieu-Duffing Oscillator by the Incremental Harmonic Balance Method CHEN Shuhui, SHEN Jianhe Abstract: A systematic procedure is presented for analyzing the bifurcations and the route to chaos of nonlinear systems. In this procedure, the periodic solutions are obtained by the Incremental Harmonic Balance (IHB) method. The stability of the periodic solutions and bifurcations are examined according to Floquet theory.  After the bifurcation value is determined, the new basic harmonic functions are constructed according to the types of bifurcations, then the IHB method and Floquet theory are employed to calculate and determine the periodic solutions and its stability until the next bifurcation point is detected. By repeating the procedure, a series bifurcation points in the transition to chaos can be determined one by one and therefore the route to chaos can be demonstrated. The bifurcation analysis of Mathieu-Duffing oscillator is taken as an example to show the efficiency and accuracy. A series period-doubling points and the threshold value at the onset of chaos are obtained. They are in good agreement with those obtained by Mathematica simulation. Key Words: incremental harmonic balance method; Mathieu-Duffing oscillator; bifurcation; route to chaos CLC Number: O322  Document Code: A  Article ID: 1000-7857(2007)22-0022-05
27  Study on the Agglomeration Kinetics of Gibbsite Particles LI Wangxing, YIN Jianguo Abstract: A further study on the effect of gibbsite particle size on its agglomeration kinetics is in order, since previous studies tell us different results. Based on a binary collision model of the agglomeration process, an agglomeration model is proposed, where particles of different sizes ri-1, ri and ri+1 are used as reactants and the method of exhaustion is adopted.  Equations of  the agglomeration rate are derived from the model and the total agglomeration rates are worked out according to the experimental data by a difference method. Equations of agglomeration rates for different particles are established. It is shown that particles of the same size have larger rate constants of agglomeration than the ones of different sizes. For particles of the same size, the particles with the smallest size have the maximum rate constants and the rate constants decrease with particle size. For particles of different sizes, the more diverse the particle sizes, the less the rate constant is. There is a good agreement between calculated kinetics results and experimental results. Key Words: kinetics; agglomeration; particle size distribution; aluminum hydroxide; seeded precipitation CLC Number: TF801.1  Document Code: A  Article ID: 1000-7857(2007)22-0027-05
32  Nonlinear Vibration Analysis of Microcantilevers in Atomic Force Microscopy HU Qingquan, TANG Qian, CHEN Liqun Abstract: Nonlinear vibration is analyzed for microcantilevers with the Lennard-Jones interaction potential. Based on the governing equation derived with Galerkin method, the near-resonant amplitude-frequency response is obtained by the method of multiple scales. The periodical motion is determined by the amplitude-frequency response. Key Words: atomic force microscopy; nonlinear system; numerical analysis CLC Numbers: TH742.9, O316  Document Code: A  Article ID: 1000-7857(2007)22-0032-04
36  A New Technique of Top Cementing Pulsation DING Shidong, GAO Deli, ZHANG Kejian, et al. Abstract: A new technique of Top Cementing Pulsation (TCP) is developed to improve the bonding quality and prevent annular gas migration in the cementing operation. A new patented hydraulic pulsation test instrument is developed to test the performance of the cement slurry under the pulsation treatment. By means of the instrument, the properties of different cement slurries were tested. The results indicate that the performance of the cement slurry can be greatly improved with the pulsation treatment, and the bonding strength and the compressive strength of cement are increased by 11～22 percent and 10～14 percent on average, respectively, and the time of initial set, the time interval between initial set and finial set, the consistence factor K are reduced by 3 percent, 12～17 percent, 16～63 percent on average, respectively.  With core analysis techniques such as electron microscope, X-ray diffraction and mercury intrusion method, the microstructure change of the cement stone and its hydration product and the pore characteristics were studied. Experimental results reveal that pulsation vibration can accelerate the hydration of the cement slurry and improve its microstructure. In addition, based on the analysis of the hydration of cement, the property of cement weight loss during the hydration and the relation between the static gel strength and the weight loss of cement slurry, the mechanism of pulsation in improving the static shear strength of cement slurry, diminishing the cement slurry weight loss and preventing gas migration is clarified in this paper.  A patented surface pulsation cementing device was developed and were used in more than 10 wells, which indicates that the cement slurry bonding quality is greatly improved and the annular gas migration is effectively prevented after cementing. Key Words: pulsation cement; cementing; cement slurry; bonding quality; annular gas migration CLC Number: TE256.+  Document Code: A  Article ID: 1000-7857(2007)22-0036-07
43  On the Construction of Intelligent Gas Early-warning System WANG Li, TIAN Shuicheng Abstract: The control and prevention of gas hazard is an important issue of safety in coal mines. There are certain limitations in information-based safety management such as gas monitoring systems at present, for example, not standardized communication protocol, poor reliability of monitoring information, not fully intelligent systems, etc. The present situation and limitations of gas monitoring systems in coal mines as well as the concepts of gas early-warning system are reviewed and discussed in this paper. The model of accident-cause theory based on three types of hazards is presented, and the structure of gas early-warning system and major modules with their basic functions are described. Finally, the methods and key points in system design are presented in order to provide some new approaches in controlling gas hazard and improving the safety in coal mines. Key Words: gas accidents; intelligent early-warning; information fusion CLC Number: TD712  Document Code: A  Article ID: 1000-7857(2007)22-0043-05
48  Real Body Modelling and Simulation of Steering Mechanism Handling Used Steering Wheel of Two Power Flow Tracked Vehicle SUN Yong, FU Tianzhi, ZHANG Hongqiong, et al. Abstract: CATIA is developed by Dassault Systems of France, as an integrated software of CAD / CAE / CAM. 3-D model building-up process for the control body and its parts is discussed in detail using CATIA in the paper, for tracked vehicles with double power flow differential turning mechanism, and the visual assembling is carried out. The movement simulation has validated the characteristics and the calculated movement of the mechanism. With CATIA 3-D as the design software platform, the electronic prototype technology is simulated, using DMU Kinematics function in Digital Mockup package.  Interference detection has been carried on whole device considering interference between parts in motion. Key Words: CATIA; tracked vehicle; two power flow steering; setting mold; motion simulation CLC Number: S219.032.3  Document Code: A  Article ID: 1000-7857(2007)22-0048-04
52  The Integration of Traffic Flow State Recognition System LIU Zhiping, WANG Fengqun, SHAN Gang Abstract: Traffic flow state recognition is one of the important issues of Intelligent Transportation Systems (ITS), especially Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems (ATIS). As an important prerequisite for taking correct measures, it is necessary to analyze road conditions, evaluate dynamical traffic information, and identify the future and real-time traffic states under different conditions timely and accurately. According to the structure of Intelligent Transportation System in our country, based on the basic concepts of dynamical traffic management, a framework of traffic state recognition system is proposed. In presenting the traffic state recognition system, the paper  puts the emphasis on the key nonparametric theory and methods used in the system. Related algorithms were tested with the field data and simulation data from the traffic simulation system software VISSIM, and the results indicate that these algorithms and models  enjoy good performance and can be used for the development of the traffic state recognition system. Key Words: traffic flow; state recognition; framework; pattern identification CLC Number: U491  Document Code: A  Article ID: 1000-7857(2007)22-0052-06
Perspectives
58  Discussion on Security of GM Food WANG Yongjia, LIAN Lixia
Reviews
63  Electrolyte in Solid Dye-sensitized Solar Cells LIN Hong, ZHUANG Dongtian, LI Xin, et al.
68  Progress in Studies on Tin-based Alloy and Composites Anode Materials for Lithium Ion Batteries LU Zhichao, LIU Zhijian, XIA Jianhua, et al.
76  The Filtration Effect of the Cigarette Filters Made of Different Fiber Filtrational Materials in Reducing Tar and Other Harmful Components HUO Xiaohui, WANG Yulin, HU Xiufeng, et al.
81  Notes on Reviews in Chinese Science Abstracts(Chinese Edition)
Science Reports
82  Is Simulation the Third Way to Know and Change the World in this Information Age?
Commentary
85  A Revelation to Chinese National Science Week from Experiences of Science Festival Management in European Countries  YU Jie, WU Yishan
86  Opening "Opening Pandora's Box" PAN Rui
87  Books Appraisal
Editor-in-chief's Thoughts
89  How to Pound the Foundation of Postgraduates Successful Research Career (XIV) FENG Changgen
Special Columns
6  Cover Story
9  Voice of Scientific Communit
10  Half-month News Briefs
12  International Journal Highlights
13  Domestic Journal Highlights
14  Scientific Community Briefs
16  Guidance for Contributors to Science and Technology Review
84  Events
88  Readers' Letters
90  Entertainment
92  Digest of Chinese Newspapers and Journals
93  Career
95  Global Jobs