中国科学院机构知识库网格系统: 检索

Planktonic ciliate community structure and its distribution in the oxygen minimum zones in the Bay of Bengal (eastern Indian Ocean) 期刊论文 OAI收割
JOURNAL OF SEA RESEARCH, 2022, 卷号: 190, 页码: 15
作者: Wang, Chaofeng; Zhao, Yanchu; Du, Ping; Ma, Xiao; Li, Suheng

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收藏 | 浏览/下载：32/0 | 提交时间：2023/02/01

Planktonic ciliate Oxygen minimum zone Community structure Environmental variables Bay of Bengal Eastern Indian Ocean

Graph-based parallel large scale structure from motion 期刊论文 OAI收割
PATTERN RECOGNITION, 2020, 卷号: 107, 页码: 11
作者: Chen, Yu; Shen, Shuhan; Chen, Yisong; Wang, Guoping

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收藏 | 浏览/下载：34/0 | 提交时间：2020/08/31

Clustering Structure from motion Minimum spanning tree

Properties of Solar Wind Dynamic Pressure Pulses at 1 AU during the Deep Minimum between Solar Cycles 23 and 24 期刊论文 OAI收割
SOLAR PHYSICS, 2015, 卷号: 290, 期号: 6, 页码: 1835-1849
作者: Xie, Y. Q.; Zuo, P. B.; Feng, X. S.; Zhang, Y.

收藏 | 浏览/下载：24/0 | 提交时间：2015/09/28

Solar wind dynamic pressure pulse The deep solar minimum Pressure balance structure Large-scale solar wind transient

Effect of design parameters on the reduction of top piston ring friction (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Computer-Aided Design, Manufacturing, Modeling and Simulation, CDMMS 2012, September 21, 2012 - September 23, 2012, Chongqing, China
作者: Wang P.

收藏 | 浏览/下载：142/0 | 提交时间：2013/03/25

In order to reduce ring-liner interface friction power loss this paper focuses on the structure parameters of the top ring and investigates how the value of those parameters will influence top ring-liner friction power loss and the minimum thickness of oil film at top ring-liner interface. A mixed lubrication model is developed to simulate the effect of varying design parameters on ring-liner friction. Case study shows that ring-liner friction power loss will be reduced with decreased axial ring height and barrel height. This study provides a theoretical basis for design the top ring with reduced friction power loss at ring-liner interface. (2013) Trans Tech Publications Switzerland.

Study on ultra-light secondary baffle for coaxial two-mirror 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: Zhang L.; Zhang L.

收藏 | 浏览/下载：70/0 | 提交时间：2013/03/25

The coaxial two-mirror telescope consists of two mirrors facing each other. Classical two-mirror arrangements are Gregorian and Cassegrain. These systems are usually applied to space telescopes and often have optical baffles to prevent stray light from entering the focal plane. The optical baffles consist of concentric rings suspended between the secondary and the primary mirror. The secondary baffle for a large two-mirror optical system is designed and analyzed in this paper. According to mission of a telescope the structure should have high stiffness and high reliability and light weight. Compared with invar aluminum alloy and titanium alloy carbon fiber composite is currently the best material in terms of weight-to-strength ratio. It also has advantages of high temperature tolerance and low thermal expansion. So carbon fiber composite is chosen as material to meet requirements of the coaxial telescope. In this paper optimization method based on finite element analysis (FEA) is used for design the secondary baffle. Minimum weight of the baffle is chosen as an objective function. Thicknesses of former tube and vanes are chosen as variables. Analysis results show that the designed secondary baffle has maximum diameter of 180mm total length of 120mm and weighs 142g. And its fundamental frequency reaches 651Hz. Therefore the baffle has many advantages such as ultra-light weight high stiffness and dimensional stability etc. The optimization method and the baffle design can be helpful to other coaxial telescopes such as Cassegrain Gregorian and their subdivisions. 2012 IEEE.

Double inverted pendulum control based on three-loop PID and improved BP neural network (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Digital Manufacturing and Automation, ICDMA 2011, August 5, 2011 - August 7, 2011, Zhangjiajie, Hunan, China
作者: Fan Y.

收藏 | 浏览/下载：43/0 | 提交时间：2013/03/25

To deal with the defects of BP neural networks used in balance control of inverted pendulum such as longer train time and converging in partial minimum this article reaLizes the control of double inverted pendulum with improved BP algorithm of artificial neural networks(ANN) builds up a training model of test simulation and the BP network is 6-10-1 structure. Tansig function is used in hidden layer and PureLin function is used in output layer LM is used in training algorithm. The training data is acquried by three-loop PID algorithm. The model is learned and trained with Matlab calculating software and the simuLink simulation experiment results prove that improved BP algorithm for inverted pendulum control has higher precision better astringency and lower calculation. This algorithm has wide appLication on nonLinear control and robust control field in particular. 2011 IEEE.

Research on model reference sliding mode control in roll stabilization of aerocraft (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
Chu H.-R.

收藏 | 浏览/下载：43/0 | 提交时间：2013/03/25

Aimed at aerospace roll stabilization control arithmetic based on model reference sliding mode variable structure theory and chattering reduction arithmetic are formulated. Correctness and validity of arithmetic are analyzed. With flight dynamics the roll-loop mathematic model and reference model are established. Sliding hyperplane is deduced based on model reference sliding mode variable structure theory. Combing with reaching law control law is derived and stability of roll-loop is analyzed. Chattering of aileron instructions is alleviate by using boundary layer approach. Digital flying simulation result shows that variable structure control arithmetic realized roll stabilization control the roll angle is less than 5.3 under powered flight and that of unpowered flight is less than 0.5 respectively. The command fin angle is less than 1.5. High frequency chattering of fin command nearby the minimum velocity was trailed off by chattering reduction arithmetic. The sliding mode control arithmetic show good performance when aerodynamic coefficients varies 20%. The control arithmetic is easy to be implemented for its simplicity. 2011 IEEE.

The application of Genetic Algorithm to CSAMT inversion for minimum structure 期刊论文 OAI收割
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION, 2008, 卷号: 51, 期号: 4, 页码: 1234-1245
作者: Li Di-Quan; Wang Guang-Jie

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收藏 | 浏览/下载：23/0 | 提交时间：2018/09/26

CSAMT genetic algorithm minimum structure inversion fitting

The application of Genetic Algorithm to CSAMT inversion for minimum structure 期刊论文 OAI收割
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION, 2008, 卷号: 51, 期号: 4, 页码: 1234-1245
作者: Li Di-Quan; Wang Guang-Jie; Di Qing-Yun; Wang Miao-Yue; Wang Ruo

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收藏 | 浏览/下载：25/0 | 提交时间：2018/09/26

CSAMT genetic algorithm minimum structure inversion fitting

Research on the support structure of the primary mirror of large-aperture telescope (EI CONFERENCE) 会议论文 OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
Yang W.; Jingxu Z.

收藏 | 浏览/下载：35/0 | 提交时间：2013/03/25

Large-aperture telescope can be used in surveying battlefield researching landform searching object real-time monitoring imaging detecting and identifying spatial targets and so on. A large-aperture telescope for achieving high resolution power is designed to monitor spatial target and image in real time. Real-time monitoring plays an important role in military conflicts. The orbit parameter of object quantity geometrical shape parameter and so on can be obtained by detect spatial target. With the development of optical technology people require larger aperture in optics-electronic (OE) system. By increasing optical aperture the ability of collecting light and resolution power in the system can be enhanced. But the support structure of the primary mirror of large-aperture telescope will be a very difficult problem. With the increase of primary mirror aperture the weight of the primary mirror will become larger than before. The root mean square (rms) of the primary mirror is affected by many factors such as deadweight deformation of heat environment and so on. Due to the primary mirror of telescope is an important component of telescope system. By reducing the weight of primary mirror precision of the system is ensured. During the designing phase one can consider the supporting project of the primary mirror synthetically and analyze it roundly according to technical requirement of optical system and the effect factors. The final structural design can be reasonable. In an astronomical telescope the surface of reflector is an important part for collecting dark radiation of celestial bodies. Its surface shape will have an effect on collecting efficiency of telescope radiant energy directly. So the rms must be very high. Optical system of large aperture small wavelength and small focus can receive maximal light intensity. For ground-based optical astronomical telescope the design proposed in the paper can satisfy the requirement of the possible minimum atmosphere seeing at astronomical observatory site and exert the use efficiency of the telescope adequately. So the accuracy of the traditional surface of reflector can assure that 90% of all the light energy can be focused on within the angle diameter range of the minimum atmosphere seeing then 100% of light energy should be focused on the angle diameter range of minimum atmosphere seeing. Because the rms of mirror is very high precise surface machining and accurate the support of mirror are very important tasks during designing and manufacturing the telescope. In the paper various support techniques of a large-aperture telescope primary mirror are discussed and a 3.5 meter telescope system at the Starfire Optical Range (SOR) overviewed simply which was operated by the Directed Energy Directorate of the Air Force Research Laboratory Kirtland AFB NM USA from the ground-based O-E system for the observations of spatial target. We also analyze Theoretical elastic deformation of the Steward Observatory 2.3 meter mirror is analyzed.