中国科学院机构知识库网格系统: 检索

Numerical study of the influence of thermal radiation on measuring semi-transparent thermal insulation material with hot wire method 期刊论文 OAI收割
International Communications in Heat and Mass Transfer, 2021, 卷号: 121
作者: Zhang, H.; Ma, Y.X.; Wang, X.; Tang, G.H.

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收藏 | 浏览/下载：27/0 | 提交时间：2021/02/03

Semi-transparent material Thermal conductivity Hot wire method Thermal radiation Test accuracy

碳氮稳定同位素比值在潮间带大型底栖动物组织间差异性研究 期刊论文 OAI收割
海洋学报, 2019, 卷号: 41, 期号: 4, 页码: 74-82
作者: 李宝泉

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收藏 | 浏览/下载：25/0 | 提交时间：2020/06/17

潮间带大型底栖动物碳氮稳定同位素食源和营养级分析采样部位选取 intertidal zone macrobenthos carbon and nitrogen stable isotopes food sources and trophic levels study,sampling parts The technique of stable isotope analysis has been widely applied for the field of food web studies in recent years.However,few researches concerned about the impacts of different tissues used for analysis on the food web building.With the purpose of accuracy and comparability in the food web studies,the sampling tissues should be standardized.In this study,10macrobenthic species from the intertidal zone of the Yellow River Delta and Yantai were chosen as the target object to test the isotopic characteristic variations ofdelta~(13)C anddelta15 N at different body parts (whole bodies,muscles and gills).Our results show thatdelta~(13)C anddelta15 N values vary in different sampling tissues for most species,which indicates the different tissues used for analysis impact the food web building.To achieve a more accuracy and comparability result,suitable tissue should be primarily chosen for their food sources and trophic levels analysis.Namely,when the organism as predator,their muscles should first be chosen,for examples,adductor and foot muscles of mollusks,leg muscles of crabs and back muscles of fishes when the organism as prey, most of their tissues,except for indigestible part(for polychaetes,the digestive tract contents should be removed) should be chosen for analysis on food sources and trophic levels of the secondary consumer,for example,whole soft parts of mollusks,the mixture of muscles and gills of crabs.

Control and accuracy assessment for the space station sun directional unit test system 会议论文 OAI收割
Sydney, Australia, December 2-4, 2019
作者: Bai XL(白鑫林); Li QS(李秋实); Zhang X(张啸); Zhao, Zhen; Liu MY(刘明洋)

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收藏 | 浏览/下载：56/0 | 提交时间：2020/05/03

Torque Control Accuracy Assessment Space Station Ground Test System

Structural design of large aperture rectangular mirror for space telescope (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Civil Engineering and Transportation, ICCET 2012, October 27, 2012 - October 28, 2012, Guilin, China
作者: Li Z.; Li Z.

收藏 | 浏览/下载：42/0 | 提交时间：2013/03/25

Structural design of large aperture mirror is one of the key technologies for space telescope development. To meet the requirements of high stiffness strength and thermal dimensional stability some factors such as support scheme materials selection lightweight design and flexible support design were taken into account. The three supports location of the mirror was determined according to the modal analytical solution. By adjusting the parameters of flexure hinge influences of gravity assembly stress and thermal stress on the mirror were reduced obviously. Finite element analysis (FEA) results indicate that the surface accuracy reach to rms10.2nm and 10.8nm under the gravity along optical axis direction and 5C uniform temperature rise respectively the fundamental frequency of the mirror component is 268Hz. Dynamics test shows that the first order natural frequency is 256Hz which shows an error less than 5% compared to FEA results. (2013) Trans Tech Publications Switzerland.

A new algorithm for solving the best-fit sphere of optical aspherical surface (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Advances in Materials and Manufacturing, ICAMMP 2011, December 16, 2011 - December 18, 2011, Guilin, China
作者: Lin J.; Lu M.

收藏 | 浏览/下载：38/0 | 提交时间：2013/03/25

To solve the best-fit sphere (BFS) accurately is one of the technological keys for the generating and testing of optical aspherical surfaces. This paper presents a new algorithm for solving the BFS of aspherical surfaces to suppress some deficiencies in the existing BFS algorithms. In the proposed approach it is not only suitable for the conic surface a BFS is constructed but also for higher order aspheres. The obtained asphericity and material removal function is more suitable for the machining and test. (2012) Trans Tech Publications which passes through both sides of endpoints in the section o -?xy of the aspherical surfaces Switzerland. the center of the BFS is shifted along the x-axis and its radius of curvature is automatically computed. The variable step size method is proposed to speed up the convergence of the iteration. Through numerically solving the BFS of conic and cubic surface the advantages of the proposed approach are verified. The results show that the proposed approach is of rapid convergence and high accuracy

Parameters estimation of BLDC motor for energy storage system (EI CONFERENCE) 会议论文 OAI收割
10th World Congress on Intelligent Control and Automation, WCICA 2012, July 6, 2012 - July 8, 2012, Beijing, China
Wu J.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

This paper presents a statistical method to estimate the parameters of the brushless dc (BLDC) motor of a flywheel system for energy storage. The principle of the estimation is based on least square estimation under a reasonable constraint. Method is suitable to avoid using complicated test apparatus. Torque constant static friction coefficient vicious friction coefficient and inertia moment can be estimated. Furthermore copper loss iron loss mechanical loss and other loss can be computed from these estimation and measurement data. By the proposed method it is demonstrated experimentally that accuracy estimation can be achieved. 2012 IEEE.

Design and experimental research of a new type focus mechanism used in space-based telescope (EI CONFERENCE) 会议论文 OAI收割
2012 9th IEEE International Conference on Mechatronics and Automation, ICMA 2012, August 5, 2012 - August 8, 2012, Chengdu, China
作者: Wang D.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

The position of focal plane will be changed because of temperature fluctuation and vacuum environment. In order to make the telescope work well positioning accuracy of the mechanism is 0.008mm. The performance satisfies the need of precision a focusing mechanism is needed. To majority of large space-based telescopes and the scheme design is reasonable and practicable. 2012 IEEE. the general way to do this would be to use a reflector which was located in the backfocal distance. One of typical schemes of this mechanism was introduced however because of the big axial size the mechanism can't be used when the size of the enclosure was limited. A new type of focusing mechanism was introduced which has such advantages of small size high accuracy and low mass. The design and test methods had been discussed. According to the results the repeatability positioning accuracy is 0.0025mm

Simulation test research of using the Ritchey-Common method for the detection of large flat mirror (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Frontiers of Advanced Materials and Engineering Technology, FAMET 2012, January 4, 2012 - January 5, 2012, Xiamen, China
作者: Zhang X.

收藏 | 浏览/下载：16/0 | 提交时间：2013/03/25

In the detection of large flat mirror the Ritchey-Common test can achieve high accuracy measurement. A method which expands the compressed images due to Ritchey Angle and rotates the plane under test is presented achieve two sets of influence functions through this we can built two equations according to two different angular positions we can solve the equations by least squares method. Then through fitting the coefficients we can get the flat errors this paper describe the simulation test of the method in order to prove the feasibility and reliability of this method. (2012) Trans Tech Publications.

Study of horizontal shafting with spherical four-way structure (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Optoelectronics and Microelectronics, ICOM 2012, August 23, 2012 - August 25, 2012, Changchun, China
作者: Yang L.; Yang L.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

Altazimuth photoelectric theodolite level shaft U-type and T-type structure but with the expanding field of applications of photoelectric theodolite the horizontal shaft structure occur great changes. For example in the marine environment shipboard conditions the instrument has a waterproof corrosion-resistant easy maintenance and other functions while carrier-based optoelectronic devices from a single visible television configure the development of integrated infrared system and ranging system as one of the single-station measurement system due to the spherical structure has sufficient internal space exactly adapted to this need. In this paper the horizontal axis of a spherical four-way structure. From aspects of the spherical four-way split in the form and shafting design and finite element analysis of the detailed design. A spherical four-way horizontal axis system diameter 550mm weight 19kg sphere in the 40kg load the maximum deformation of 3.3m fully meet the requirements. The shaft of the structure of the shaking is less than 2 arc seconds the vibration test the re-examination instrument accuracy change is less than 1 arc seconds. Verify that the structure is stable and reliable. 2012 IEEE.

Adaptive control at launching using three loop autopilot (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011, July 15, 2011 - July 17, 2011, Inner Mongolia, China
作者: Zhang Y.

收藏 | 浏览/下载：25/0 | 提交时间：2013/03/25

In order to guarantee the precise initial flight trajectory control the missile disturbance of large disturbance torque three loop adaptive autopilot was researched. The characteristics of the projectile and three loop autopilot instruction formation characteristics were analysed. From equivalent pitching angle of lateral acceleration feedback loop combined with the instruction of generalized error autopilot structure was simplified and three loop autopilot adaptive control law and stability were designed. The test data show that when disturbance torque was 600Nm the attitude angle generalized error was -4.4. In the time lasted about 15s late trajectory accuracy was within 1.0.Three loop autopilot adaptive control law was able to control the disturbance of initial trajectory and adapt to dynamic characteristics changes control system stability. It was the initial trajectory accurate solution method of flight. 2011 IEEE.