Jiuquan Satellite Launching Center

Jiuquan, China

Jiuquan Satellite Launching Center

Jiuquan, China
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Peng Y.,China Maritime Police Academy | Hu Z.-H.,Jiuquan Satellite Launching Center | Shen H.-R.,Academy of Equipment Command and Technology
Dianzi Yu Xinxi Xuebao/Journal of Electronics and Information Technology | Year: 2013

Jousselme advanced the distance of evidence to measure the degree of difference between evidence that represents the identification result and evidence that represents the real solution. The distance of evidence becomes smaller with the increase of dispersion of evidence's basic probability assignment. And for two totally different evidences, the distance is less than one unless the two evidences are both category ones. Therefore, the distance of evidence proposed by Jousselme is unsuitable to measure the difference between two evidences. Aiming at this problem, a modified distance of evidence is put forward. Numerical examples indicate that the modified distance of evidence extendes the application scope of distance proposed by Jousselme for measuring the difference between evidences.


Zhao D.,Academy of Equipment Command and Technology | Zhao D.,Jiuquan Satellite Launching Center | Yang H.,Academy of Equipment Command and Technology | Jiang J.,Jiuquan Satellite Launching Center | And 2 more authors.
Proceedings - 2011 International Conference of Information Technology, Computer Engineering and Management Sciences, ICM 2011 | Year: 2011

Aiming at the problems of the centrality of article edit collective in wikipedia, under the direction of the idea of networked data mining, featured articles in wikipedia were analyzed by text processing to find the difference of sentences between adjacent versions and identify the edit interaction connection between editors, then the article edit interaction networks were constructed, where the node is editor and the link is the edit interaction connection between editors, then degree, betweenness and closeness and topology potential were used to analyze empirically the local centrality of article edit interaction networks. Results show that the cumulative distributions for degree, betweenness and topology potential of nodes follow shifted power law distribution, closeness follows normal distribution, and there are many nodes with small degree and betweenness but big closeness, there are few nodes with big degree, betweenness and closeness. There isn't an absolute center in the networks. However the edit collective have strong heterogeneity and local community structure and topology potential can synthetically characterize the centrality of nodes. The method can effectively find the central nodes in the networks and the research deepens the knowledge of the characteristic of collective edit interaction and collective intelligence. © 2011 IEEE.


Ma S.-N.,Academy of Armored force Engineering | Suo X.-B.,Jiuquan Satellite launching Center | Qiu J.,Academy of Armored force Engineering | Zhu H.-Y.,Academy of Armored force Engineering
Hangkong Cailiao Xuebao/Journal of Aeronautical Materials | Year: 2012

Al 2O 3 coatings embedded with SiO 2 nanoparticles were produced on 7A52 aluminum alloy by adding SiO 2 nanoparticles into the electrolyte. The effect of n-SiO 2 on the growth kinetics of the micro-arc oxidized coating under the two modes of constant voltage and constant current was investigated. The results show that nano-SiO 2 increased the growth rate of micro-arc oxidized coating and the current efficiency. Nano-SiO 2 is formed impurity energy level and narrowed band gap, so that impurity discharge is existed during the breakdown process and promoted the micro-arc oxidation process of electrical breakdown, resulting in the improvement of the growth efficiency of micro-arc oxidized coating.


Wang T.,Shijiazhuang Mechanical Engineering College | Ma L.,Shijiazhuang Mechanical Engineering College | Jia J.,Jiuquan Satellite Launching Center | Li S.,Shijiazhuang Mechanical Engineering College
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2012

The damages of a substructure were identificated by the proposed identification method. Numerical simulation examples indicate that the damage location and severity in structures, with single damage or multiple ones, can be detected efficiently by GMFCD through only a few of the lower order modal parameters. Compared to the aforementioned flexibility indicators, such as the change in flexibility, flexibility differential curvature method, the effectiveness and advantages of GMFCD are shown.


Chen L.,Wuhan Naval University of Engineering | Wang J.,Wuhan Naval University of Engineering | Wang J.,Jiuquan Satellite Launching Center | Sun F.,Wuhan Naval University of Engineering
International Journal of Sustainable Energy | Year: 2011

In this paper, the power density, defined as the ratio of power output to the maximum specific volume in the cycle, is taken as the objective for performance analysis of an endoreversible closed intercooled regenerated Brayton cycle coupled to variable-temperature heat reservoirs from the viewpoint of finitetime thermodynamics (FTT) or entropy generation minimization. The analytical formulae for the relations between power density and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers, the intercooler, and the regenerator. Some results in the recent FTT literature are replicated. The intercooling pressure ratio is optimized for dimensionless power density. The effects of component (the intercooler, the regenerator, and the hot- and cold-side heat exchangers) effectivenesses, the thermal capacity rate of the working fluid, the heat reservoir inlet temperature ratio, and the inlet temperature ratio of the cooling fluid in the intercooler and the cold-side heat reservoir on maximum power density and its corresponding efficiency and intercooling pressure ratio are analysed using detailed numerical examples. The obtained results are compared with those obtained by using the maximum power criterion, including the cycle efficiencies, the normalized maximum specific volumes, and the normalized maximum specific volume differences at two design objectives. The advantages and disadvantages of maximum power density design are obtained via comparison of the main parameters of the cycle at maximum power and maximum power density conditions. The regeneration makes the maximum dimensionless power density decrease, and the intercooling makes the maximum dimensionless power density increase. The finite thermal capacity rates of the heat reservoirs do affect the performance of the variable-temperature heat reservoir cycle even for reversible cycles free of heat transfer irreversibility in general. The maximum power density design has the advantage of smaller size, but it requires a higher pressure ratio and has a lower efficiency than the maximum power design. © 2011 Taylor & Francis.


Wang J.,Wuhan Naval University of Engineering | Wang J.,Jiuquan Satellite Launching Center | Chen L.,Wuhan Naval University of Engineering | Sun F.,Wuhan Naval University of Engineering
International Journal of Low-Carbon Technologies | Year: 2010

In this paper, the power density, defined as the ratio of power output to the maximum specific volume in the cycle, is taken as objective for performance analysis of an endoreversible, closed, intercooled regenerated Brayton cycle coupled to constant-temperature heat reservoirs in the viewpoint of finitetime thermodynamics or entropy generation minimization. The analytical formulae about the relations between power density and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers, the intercooler and the regenerator. The intercooling pressure ratio is optimized for dimensionless power density. The effects of effectivenesses of the intercooler and the regenerator on the optimal dimensionless power density and its corresponding efficiency are analyzed by detailed numerical examples. The obtained results are compared with those results obtained by using the maximum power criterion, including the cycle efficiencies, the normalized maximum specific volumes and the normalized maximum specific volume differences at two design objectives. The advantages and disadvantages of maximum power density design are obtained via the comparison of the main parameters of cycle at the maximum power and maximum power density conditions. The effects of turbine and compressor losses on the cycle performance are analyzed. © The Author 2010. Published by Oxford University Press. All rights reserved.


Wang J.,Wuhan Naval University of Engineering | Wang J.,Jiuquan Satellite Launching Center | Chen L.,Wuhan Naval University of Engineering | Ge Y.,Wuhan Naval University of Engineering | Sun F.,Wuhan Naval University of Engineering
International Journal of Sustainable Energy | Year: 2014

An endoreversible closed modified simple Brayton cycle model with isothermal heat addition coupled to variable-temperature heat reservoirs is established using finite-time thermodynamics. Analytical expressions of dimensionless power output, thermal efficiency, dimensionless entropy generation rate and dimensionless ecological function are derived. Influences of cycle thermodynamic parameters on ecological performance and optimal compressor pressure ratio, optimal power output, optimal cycle thermal efficiency and optimal entropy generation rate corresponding to maximum ecological function are obtained and compared with those corresponding to maximum power output. The results show that cycle thermal efficiency improvement and entropy generation rate reduction are obtained at the expense of higher compressor pressure ratio and a little sacrifice of power output at maximum ecological function. The compromises between power output and entropy generation rate and between power output and cycle thermal efficiency, respectively, are achieved. © 2013 Taylor & Francis.


Hu Z.-H.,National University of Defense Technology | Hu Z.-H.,Jiuquan Satellite Launching Center | Zhu J.-B.,National University of Defense Technology | He F.,National University of Defense Technology | Liang D.-N.,National University of Defense Technology
Dianzi Yu Xinxi Xuebao/Journal of Electronics and Information Technology | Year: 2012

The performance of Direction-Of-Arrival (DOA) estimation of classical algorithms may degrade substantially in the presence of mutual coupling. In this paper, a blind source separation based algorithm is proposed for DOA estimation using uniform linear array. Firstly, the generalized array manifold matrix is estimated using blind source separation techniques; Then, based on the property that the mutual coupling matrix of uniform linear array can be modeled by a symmetric Toeplitz matrix, DOA estimation problem is transformed into multiple separable nonlinear least squares problems, and DOAs can be obtained by multiple one-dimensional peak searching. The proposed algorithm does not need multidimensional peak searching or multidimensional iteration, and imposes weaker constraints on the number of non-zero coefficients in the mutual coupling matrix. Besides, the proposed algorithm is applicable even if the number of non-zero coefficients in the mutual coupling matrix is unknown. Simulation results demonstrate the effectiveness of the proposed algorithm.


Jia L.-D.,Jiuquan Satellite Launching Center | Wang J.-A.,Jiuquan Satellite Launching Center | Yang Z.-T.,Jiuquan Satellite Launching Center | Tu G.-Y.,Jiuquan Satellite Launching Center
Yuhang Xuebao/Journal of Astronautics | Year: 2012

Leak-testing room is an important equipment for the spaceship leaking analysis in the launching site. First, the basic structure and elements of the spaceship leak-testing rooms are introduced, and the mathematical model of the leaking process is built by using a pinhole-leaking model, and simulated by using MATLAB. After that, the leak paths of the labyrinth packing structure of the spaceship leak-testing room is analyzed, and a failure tree model of all possible leak factors is built. Leaking positions, causes and mechanism are specified through excludable experiments. After the aimed maintenances, the leakage of the spaceship leak-testing room can be controlled in <100 Pa/24 h, which satisfies the original requirement (<150 Pa/24 h). Experiments indicate that the method is simple and effective.


Li T.,Jiuquan Satellite Launching Center
Journal of Mechanical Design, Transactions of the ASME | Year: 2012

The spherical gear is a gear-driven mechanism with two degrees of freedom (DOF), which can transfer spatial motion. The spherical gear pairs have two types of basic assembly structures including an ideal mechanism and a gimbal mechanism, and whose kinematic characteristics are analyzed. The 2-DOF gearing principle of conjugate tooth surfaces of the spherical gear pair is introduced first. Then, the relative slide between two tooth surfaces in the mesh is analyzed. Finally, the equations of the meshing coned surface and the conjugate surface are established based on the meshing models of the spherical gear pairs. Furthermore, the sliding ratios of the tooth surfaces of the spherical gear pairs are obtained when they mesh in different meshing conditions based on two-parameter movement analysis. The computational results show that the sliding ratios of the spherical gear teeth are related to the angle velocity ratio in the ideal mechanism and they are not only related with angle velocity ratio but also related with the assembly axes in the gimbal mechanism, which are useful in theory for further studying the wear of the spherical gear. © 2012 American Society of Mechanical Engineers.

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