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   Science & Technology Review
2014, Vol.32, No. 22
08 August 2014

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Science & Technology Review. 2014, 32 (22): 0-0.
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Science & Technology Review. 2014, 32 (22): 1-1.
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Science & Technology Review. 2014, 32 (22): 7-7.
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Science & Technology Review. 2014, 32 (22): 9-9.
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Science & Technology Review. 2014, 32 (22): 11-11.
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Science & Technology Review. 2014, 32 (22): 12-12.
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Science & Technology Review. 2014, 32 (22): 84-84.
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Science & Technology Review. 2014, 32 (22): 87-87.
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Science & Technology Review. 2014, 32 (22): 88-88.
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Science & Technology Review. 2014, 32 (22): 89-89.
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Science & Technology Review. 2014, 32 (22): 6-6.
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Science & Technology Review. 2014, 32 (22): 10-10.
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Science & Technology Review. 2014, 32 (22): 13-13.
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Science & Technology Review. 2014, 32 (22): 14-14.
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Science & Technology Review. 2014, 32 (22): 85-85.
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Science & Technology Review. 2014, 32 (22): 93-95.
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Articles

Characteristic Analysis of Stochastic Open Quantum Systems via Lyapunov-based Control

CONG Shuang, HU Longzhen, XUE Jingjing, WEN Jie
Science & Technology Review. 2014, 32 (22): 15-22. ;  doi: 10.3981/j.issn.1000-7857.2014.22.001
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Abstract ( 199 )
Quantum measurement brings a stochastic term to deterministic open quantum systems, which makes the systems display some unique characteristics distinguished from the Markovian and non-Markovian open quantum systems. These characteristics bring some new roles to and effect on the stochastic open quantum system. Based on the related work on the global stability for stochastic open quantum systems via Lyapunov stabilization theorem established recently, the characteristic analysis without control fields and the state transfer with the switching control and continuous control are studied, respectively. Numerical simulation experiments are implemented under the Matlab environment. The simulation results demonstrate that the system without the action of the control will randomly converge to some eigenstate of the measurement operator and the numbers of eigenstates and diagonal non-zero elements of the initial state's density matrix are equal, and that under the action of the control, the stochastic open quantum system can transfer the state from an arbitrary initial pure state to the desired target eigenstate.However, compared to the switching control, the continuous control system performance has a faster convergence speed and a shorter transfer time.

Numerical Simulation of Mixed Scavenging Methods for Two-stroke Diesel Aero Engines

CHEN Qiangen, ZHANG Xiangjian, PAN Zhongjian, XU Xiaolong
Science & Technology Review. 2014, 32 (22): 23-28. ;  doi: 10.3981/j.issn.1000-7857.2014.22.002
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Abstract ( 267 )
This paper establishes a three-dimensional scavenging model and a gas flow mathematical model of the inner cylinder for one type of two-stroke diesel aero engine, and analyzes the structure of the gas ports. The calculation domain of the model is meshed by the methods of the multiple block coupling and bonding technology, and the boundary conditions are set by the GT-power. The Fluent software is applied to simulate the three-dimensional gas flow in the inner cylinder. The research results show that the cross scavenging easily produces scavenging blind spots at the weak flow area; the loop scavenging can form a preferable backflow at the radial direction, but the axial velocity is lower, decreasing the scavenging efficiency; The mixed scavenging reduces the scavenging blind spots and forms better spiral vortexes and higher axial swirls, and increases the exhaust velocity by 12.6% and 125.2%, respectively compared with the loop scavenging and the cross scavenging.

Realization of the Viscoelastic Boundary Conditions Based on Wave Equations in Ansys Software

LIN Yi, WANG Zhaoling, LIU Zhengping, NIU Dongxing
Science & Technology Review. 2014, 32 (22): 29-33. ;  doi: 10.3981/j.issn.1000-7857.2014.22.003
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Abstract ( 356 )
This paper researched boundary conditions of numerical simulation of seismic wave field in the application of finite element software Ansys. We propose a viscoelastic boundary conditions based on wave equation. Deduced from the wave equation and a viscoelastic boundary conditions theoretical foundation established, we selected damping Combin 14 unit as load finite element method, adopted APDL code successfully to apply viscoelastic boundary conditions in Ansys. The examples set up a virtual detector in the model boundaries, loaded Ricker wavelet source, extract wave field snapshot and time recording. Compared results demonstrate that viscoelastic boundary conditions imposed can well absorb boundary reflection, it shows the effectiveness of the viscoelastic model boundary conditions.

Analysis of Cement Pillar Stability Based on Hyperstatic Structure Theory and Numerical Simulation

YU Jian, WANG Guihuang
Science & Technology Review. 2014, 32 (22): 34-37. ;  doi: 10.3981/j.issn.1000-7857.2014.22.004
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Abstract ( 208 )
In order to evaluate the stability of cement pillar scientifically and accurately, an analytic evaluation method that is based on the theory of statically indeterminate structure and numerical simulation is proposed. An artificial pillar is simplified to a statically indeterminate structure and the maximum stress is calculated by an indeterminate model using the comprehensive action of tailings backfill lateral pressure, top loose rock pressure and its own gravity. The pillar stability is tested by uniaxial compressive test data on cemented waste-rock and the finite element analysis software Midas, which is used to simulate the loading force and output the effective stress and strain-displacement. The cement pillar of Dahongshan copper mine is used as an example, and it is shown that the maximum stresses by statically indeterminate theory and simulation software are 6.27 MPa and 3.55 MPa, respectively, the maximum strain-displacement is 40.46 mm, and the cemented waste-rock uniaxial compressive strength is 10.9 MPa. All of the above shows that it is feasible to test the pillar stability by the method of statically indeterminate and numerical simulation.

Control Standard of CFG Pile Treatment of Highway Soft Ground Based on Isostatic Settlement

WANG Huan, WANG Xuancang, GAO Zhiwei
Science & Technology Review. 2014, 32 (22): 38-41. ;  doi: 10.3981/j.issn.1000-7857.2014.22.005
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Abstract ( 207 )
To propose a control standard of highway soft ground isostatic settlement, the relationships of the pile spacing, length, modulus and the maximum settlement on the top soft ground are analyzed using the established CFG pile treatment model of highway soft ground by ANSYS finite element. The results show that with the increase of CFG pile spacing the maximum settlement on the top soft ground increases correspondingly, while the maximum settlement on the top soft ground reduces correspondingly with the increase of length and modulus. The greatest impact on the maximum settlement on the top soft ground is the CFG pile spacing, therefore the pile spacing is taken as the control standard of CFG Pile treatment of highway soft ground settlement. Different control standards of highway soft ground isostatic settlement of combinations of CFG pile spacings are proposed.

Riding Stability of Urban Straddle-type Monorail Vehicles Under Lateral Wind

ZHAO Shuen, LIU Xi, DU Zixue, LI Yuling
Science & Technology Review. 2014, 32 (22): 42-46. ;  doi: 10.3981/j.issn.1000-7857.2014.22.006
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Abstract ( 217 )
This research focuses its attention on the riding stability of straddle-type monorail vehicles under the lateral wind condition by means of the multi-body dynamics analysis software Adams to set up a "car body-tire-track beam" coupled system model for the straddle-type monorail vehicle. Then, based on the principles of aerodynamics and considering that the wind pressure center changes as a result of the movement of the vehicle, calculation and contrastive analysis of the riding stability of straddle-type monorail vehicle under various car speeds, wind speeds and track shapes are performed through simulation. Finally, the conclusion is arrived at that changes of car speed and wind speed can exert a great influence on the transverse acceleration of straddle-type monorail vehicles affected by lateral wind, and an excessive speed of vehicle or wind may result in imbalance of the vehicle, which can possibly act as a reference for further exploring the crosswise riding stability and safety of straddle-type monorail vehicle under lateral wind.

Research on Reliability Design Method of Airport Runway Width

CEN Guoping, LU Song, HONG Gang, LIN Kexin, XU Feng
Science & Technology Review. 2014, 32 (22): 47-51. ;  doi: 10.3981/j.issn.1000-7857.2014.22.007
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Abstract ( 199 )
In order to adapt to the development of modern aircraft and design the dimension of airport runway more reasonably, the problem of airport runway width is studied systematically. A computing method of the plane's basic demand for the airport runway width is elaborated. The theory of reliability is drawn into the design of runway width, which makes up for the deficiency of just relying on the flying requirement and experience to design the width. Based on the statistical analysis of meteorological data and transverse distribution of aircraft landing marks of a airport, the crosswind without a part of 0 wind is subject to the extreme I type distribution and landing marks are subject to normal distribution. According to the Monte Carlo method, the runway width is calculated under different failure probabilities by Matlab, followed by the reliability evaluation of the present runway width. The result shows that the runway width isn't sensitive to the change of air density and the theoretic failure probability is close to the actual failure probability, which is practically significant.

Quality Classification of Rock Mass Based on Attribute Recognition Model of Entropy Weight

LIU Zhixiang, WU Diemei, TANG Zhixiang
Science & Technology Review. 2014, 32 (22): 52-56. ;  doi: 10.3981/j.issn.1000-7857.2014.22.008
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Abstract ( 180 )
In order to overcome subjective and erroneous tendency problems existing in expert determination methods in assessment of classification for rock mass quality, an attribute recognition model for rock mass quality classification criterion is established based on the entropy weight theory which can confirm the relevant entropy coefficients of evaluation indexes and combines the attribute recognition theory. The model chooses rock uniaxial compressive strength, RQD, structural face interval, friction coefficient, rock drilling speed and acoustic velocity of rock mass as the comprehensive evaluation indexes. The paper takes seven stopes of Sanshan island gold mine as the research background to develop the model. And it has successfully given an attribute measure for each index based on its weight, and obtained the ranking and classification of rock quality according to the criterions of confidence degree and rating. The result shows that the attribute recognition results are more accurate than those of RMR method, and that the evaluation results are objective and reliable.

Research on Mining Area Transition Mode in Mengdong Western No. 2 Surface Coal Mine

BAI Runcai, LI Chengsheng, LIU Guangwei
Science & Technology Review. 2014, 32 (22): 57-61. ;  doi: 10.3981/j.issn.1000-7857.2014.22.009
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Abstract ( 468 )
A large coal field is usually divided into several mining areas in surface coal mine, therefore the steering transition problem between adjacent mining areas must be considered. This paper first analyzes five kinds of steering transition modes and compares the specific characteristics of these steering modes. Considering the actual production status of a surface mine, SMCAD, a computer-aided-design platform, is used for 3D geological modeling to study the mining. The advantages and disadvantages of four kinds of continuous steering transition modes are compared, and the variation of stripping ratio, transient time, load distance and total cost for each transition mode are revealed. Finally, a right angle turn left ditch optimal program is determined as the optimal scheme. This research achievement has a guiding significance for practical production in surface coal mine.

Relationship Between Fractures and Hydrocarbon Accumulation of Triassic Tight Sandstones in the North of Dongpu Depression

WANG Pingxia, GONG Lei, DU Yijing, GAO Shuai, WENG Jianqiao, SU Hui, HUANG Jianguo
Science & Technology Review. 2014, 32 (22): 62-66. ;  doi: 10.3981/j.issn.1000-7857.2014.22.010
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Abstract ( 283 )
The distribution of the natural fractures controls the distribution and the accumulation of the hydrocarbon reservoir in the Triassic of Wenmingzhai area, Dongpu depression. The formation time of the fractures and the relationship between the effective evolution law and the hydrocarbon generation peak determine the behavior of the hydrocarbon reservoir. Based on the data of outcrops, cores, thin sections, logs, sound emission experiments, fluid inclusion analyses, oil component analyses and carbon isotope analyses, the distribution characteristics of the fractures, the fracture sequence and the relationship between the fractures and the hydrocarbon accumulation are discussed. The results show that the structural fracture is the dominant fracture type in the reservoirs of Triassic tight sandstone in the north of Dongpu Depression. The average porosity of the fractures and the related dissolved pores is 2.25%, and the average permeability is about 40×10-3 μm2. The fractures and the related dissolved pores are important storage spaces and seepage channels. The fractures of the tight sandstone reservoir of Triassic are formed in two stages. The oil sources of Triassic are the source rocks of Sha3 and Sha4 Member of Palaeogene whose peak period of the hydrocarbon generation is the period when the Dongying-Guantao Formation is formed. But the diagenesis was completed before Cenozoic. The period of the hydrocarbon generation is well matched with the effective fractures, while it is poorly matched with the pores. It follows that the oil is contained in the fractures rather than in pores. The distribution of oil reservoirs is controlled by the development of fractures and high part of the structure.

Quantitative Characterization of Permeability Based on the Pore and Throat Distribution Constraint

ZHANG Jianmin, JIANG Yuanpeng, HUANG Kai, SU Yanchun
Science & Technology Review. 2014, 32 (22): 67-72. ;  doi: 10.3981/j.issn.1000-7857.2014.22.011
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Abstract ( 267 )
Low permeability reservoirs are becoming a focus of the offshore oilfield development technologies. The permeability can be controlled by the pore structure, and the quantitative characterization of the permeability can be established based on the relationship between the porosity and the permeability However, this kind of relationship is not very reliable, which reduces the accuracy of the permeability calculation. This paper proposes a new method of the permeability quantitative characterization based on the pore and throat distribution constraints. The pore space is divided into different types based on the size of the pore throat radius, which are given different weights to characterize the effect of the pore throat radius, and the sum of all weighted pore spaces is defined as the pore throat volume coefficient. Compared with the traditional method, the coefficient of the permeability has a better correlation. Through the introduction of the NMR logging in the new method, for a continuous distribution of the permeability interpretation, the application results show that the permeability explained by the new method enjoys a high accuracy, therefore, this method provides a viable technology for the permeability characterization of low permeability reservoirs.

Preparation and Performance of Composite MAO Film with Nano-ZrO2 Particles on Pure Aluminum Alloy

OUYANG Xiaoqin, ZHOU Linyan, YU Bin, WAN Ying, ZHANG Binbin, HU Shuilian, FENG Changjie
Science & Technology Review. 2014, 32 (22): 73-76. ;  doi: 10.3981/j.issn.1000-7857.2014.22.012
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Abstract ( 348 )
In this paper, aluminum is used as substrate and micro-arc oxidation (MAO) films are prepared on pure aluminium in the electrolyte with ZrO2 particles. The surface morphologies and composition of micro-arc oxidation composite film are investigated by means of SEM and EDS. This paper studies the effects of nano-particle ZrO2 added in micro-arc oxidation composite film on the microhardness and corrosion resistance of the film. The results show that the surface of micro-arc oxidation film and its composite membrane are rough, and that the ZrO2 nano-particles which are added in the film can reduce crack, decrease pore size, and improve the microhardness and corrosion resistance of the micro-arc oxide film.
Reviews

Research Progress of the Precious Metal-support Interaction in CeO2-based Catalysts

WENG Duan, LI Min
Science & Technology Review. 2014, 32 (22): 77-83. ;  doi: 10.3981/j.issn.1000-7857.2014.22.013
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Abstract ( 173 )
Precious metal (PM)-support interaction is one of the most attractive directions in current research on PM supported ceriabased catalysts. In this paper, the possible mechanisms that explain the occurrence of PM-support interaction, the influence of this interaction on catalytic reactions as well as the corresponding research progress in control of this interaction are summarized. Moreover, potential research orientations on PM-support interaction in the future are prospected.

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