中国科学院机构知识库网格系统: 检索

Programming chain-growth copolymerization of DNA hairpin tiles for in-vitro hierarchical supramolecular organization 期刊论文 OAI收割
NATURE COMMUNICATIONS, 2019, 卷号: 10, 期号: -, 页码: —
作者: Zhang, HL; Wang, Y; Zhang, H; Liu, XG; Lee, A

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收藏 | 浏览/下载：49/0 | 提交时间：2019/12/30

TARGETED TRANSPORT ACCURATE DESIGN NANOTECHNOLOGY NANOTUBES POLYMERIZATION NANOPARTICLES HYDROGELS DELIVERY TUBE

Design of semi-physical simulation for small satellite by virtual display (EI CONFERENCE) 会议论文 OAI收割
2011 3rd International Conference on Mechanical and Electronics Engineering, ICMEE 2011, September 23, 2011 - September 25, 2011, Hefei, China
Xu K.; Lv Y.; Jin G.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

Semi-physical simulation of attitude control system is the more synthetically test and verify for designing of small satellite control system. It is an important means of small satellite development. However the results of current semi-physical simulation system have a lot of non-intuitive. Compare with the actual environment the simulation environment still has striking disparity. So the shortcomings affect precision of simulation. Based on the virtual display technology the group semi-physical simulation system has been constructed for attitude control of small satellite due to the combination with xPC real-time environment the simulation computer high-precision single-axis air-bearing turntable reaction wheel air thrust device fiber gyroscopes sensors synchronizer power subsystem and wireless devices virtual display computer etc. Semi-physical simulation achieved the visual simulation in orbit and tracked new information of virtual environment of space into real-time simulation computer. Simulation results show that the simulation system for real-time attitude and orbit position of small satellite semi-physical simulation has an excellent display effect. At the same time Real-time transfuse of orbit information provides a more accurate space environment simulation. The simulation system of small satellite attitude control to design and evaluate the more direct and convenient. (2012) Trans Tech Publications Switzerland.

Design of thermostat system based on Proteus simulation software (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
Han Z.; Song K.

收藏 | 浏览/下载：39/0 | 提交时间：2013/03/25

In order to solve the problem of precise temperature control the thermoelectric cooler (TEC) principle widely used is analyzed for the design of the whole control process and selection of control parameters and then accurate simulation model of the TEC is established in Proteus simulation software. Moreover combined with the traditional circuit simulation model the temperature control loop is designed and the response characteristics of the system are tested using an input signal similar to the unit-step function to achieve the precise temperature control. Simulation results show that the proposed control circuits can precisely convert error signal to output voltage sent to TEC model and TEC model behaves approximately like a two-pole system. The first pole starts at 20mHz and a second pole at 1Hz. 2011 IEEE.

Establishment of airplane flight model and simulation analysis of landing behavior (EI CONFERENCE) 会议论文 OAI收割
2nd Annual Conference on Electrical and Control Engineering, ICECE 2011, September 16, 2011 - September 18, 2011, Yichang, China
作者: Li L.; Li M.

收藏 | 浏览/下载：25/0 | 提交时间：2013/03/25

This paper create a high fidelity plant model of an aircraft landing gear to inclusion into a full aircraft flight simulation for accurately analyzing the performance and influence of landing gear system. The use of domain specific modeling software enables detailed modeling of the physics and facilitates accurate computational simulation of the flight dynamic aerodynamic landing gear dynamic and mechanical loads that occur when the landing gear are deployed and retracted during landing and take-off operations. The parameter design space is easily searched by considering a number of different landing scenarios including touching down on one wheel first to optimize the design. The simulation results show that the aircraft landing gear system mathematical model established appropriately reflects the change of force and moment in the process of taking off and landing and it is actual in the physical process. 2011 IEEE.

Aircraft landing gear simulation using multidomain modeling technology (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Information Technology, Computer Engineering and Management Sciences, ICM 2011, September 24, 2011 - September 25, 2011, Nanjing, Jiangsu, China
作者: Li M.

收藏 | 浏览/下载：41/0 | 提交时间：2013/03/25

In order to accurately analyze the performance and influence of landing gear system this paper presents a high fidelity plant model of an aircraft landing gear to inclusion into a full aircraft flight simulation. The use of domain specific modeling software enables detailed modeling of the physics and facilitates accurate computational simulation of the flight dynamic aerodynamic landing gear dynamic and mechanical loads that occur when the landing gear are deployed and retracted during landing and take-off operations. The parameter design space is easily searched by considering a number of different landing scenarios including touching down on one wheel first to optimize the design. The simulation results show that the aircraft landing gear system mathematical model established appropriately reflects the change of force and moment in the process of taking off and landing and it is improve the precision of flight simulation. 2011 IEEE.

Using bidirectional binary particle swarm optimization for feature selection in feature-level fusion recognition system (EI CONFERENCE) 会议论文 OAI收割
2009 4th IEEE Conference on Industrial Electronics and Applications, ICIEA 2009, May 25, 2009 - May 27, 2009, Xi'an, China
作者: Wang D.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

In feature-level fusion recognition system the other is optimizing system sensor design to get outstanding cost performance. So feature selection become usually necessary to reduce dimensionality of the combination of multi-sensor features and improve system performance in system design. In general there are two main missions. One is improving the recognition correct rate as soon as possible the optimization is usually applied to feature selection because of its computational feasibility and validity. For further improving recognition accuracy and reducing selected feature dimensions this paper presents a more rational and accurate optimization Bidirectional Binary Particle Swarm Optimization (BBPSO) algorithm for feature selection in feature-level fusion target recognition system. In addition we introduce a new evaluating function as criterion function in BBPSO feature selection method. At the last we utilized Leave-One-Out method to validate the proposed method. The experiment results show that the proposed algorithm improves classification accuracy by two percentage points while the selected feature dimensions are less one dimension than original Particle Swarm Optimization approach with 16 original feature dimensions. 2009 IEEE.

Equivalent lenses of supersonic seeker's outflow refractive index field obtained by simulation and experiment (EI CONFERENCE) 会议论文 OAI收割
2008 International Conference on Optical Instruments and Technology: Optical Systems and Optoelectronic Instruments, November 16, 2008 - November 19, 2008, Beijing, China
Qun W.; Hongguang J.; Ming X.

收藏 | 浏览/下载：25/0 | 提交时间：2013/03/25

In order to decrease the aerodynamic drag of supersonic image guide missile and design a non-spherical dome the outflow field of the missile's dome is simulated using FLUENT. Based on the simulated results the accurate density field of the outflow field at all kinds of flight conditions is obtained and then the refractive index field of the outflow field is gotten according to the Gladstone-Dale law. The results show that the shock wave induces the heterogeneity of the refractive index field and the turbulent causes distortion. The outflow field is divided into several zones which are taken as equivalent lenses for aberration analysis. 2009 SPIE.

Imaging analysis of a novel compound diffractive telescope system (EI CONFERENCE) 会议论文 OAI收割
Optical Manufacturing and Testing VIII, August 4, 2009 - August 5, 2009, San Diego, CA, United states
作者: Liu H.; Liu Y.; Liu Y.; Liu Y.; Zhang H.

收藏 | 浏览/下载：35/0 | 提交时间：2013/03/25

The main feature of the compound diffractive telescope is the combination of diffractive optics with compound structure arranged eyepieces. In this paper a design of the compound diffractive telescope is firstly introduced and a 4.2 FOV is obtained with one primary lens and twenty-one eyepieces. Secondly image characteristic of different channels is analyzed with the design wavelength in ASAP and one modified phase function model of diffractive optical element is introduced to analyze the MTF curves for 0 FOV which provides a more accurate prediction of the performance of the system. Then the system is tested by the star image test and the diffraction limit images are got within 2 FOV. And finally two pictures taken from the adjacent FOV proved to be able to be spliced together. All the results above demonstrate that a good performance of the compound diffractive telescope. 2009 SPIE.

Application of CMOS APS star tracker with large FOV in attitude and angular velocity determination (EI CONFERENCE) 会议论文 OAI收割
Advanced Sensor Systems and Applications III, November 12, 2007 - November 14, 2007, Beijing, China
Lu D.; Guang J.; Shaoju W.; Tao C.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

The paper deals with the spacecraft attitude determination problem using a new kind of star tracker with large FOV based on CMOS APS. Star tracker has been developed since 1970s and proved to be the most accurate sensor ever used in the spacecraft attitude determination systems. But the traditional CCD star tracker also has some disadvantages such as small FOV high power consumption low sample rate and low working angular rate limit which prevent the use of CCD star tracker in attitude large angle maneuvering process. The new kind of star tracker based on CMOS APS has no such disadvantages and is more applicable on modern low-cost agile small satellites. Its higher sample rate and working angular rate limit over traditional CCD star tracker make it more adapt for spacecraft angular velocity determination. Because of the large FOV of the star tracker the mathematical model of traditional CCD star tracker with a small FOV is not appropriate. So a new mathematical model was quoted to fit the star tracker with a large FOV. An alternative adaptive algorithm was also introduced in the paper. It can help the EKF algorithm work lacking of accurate covariance of the observation noise. An optimal estimation algorithm was used to estimate the angular velocity directly from the star tracker measurements. Mathematic simulation results indicate the CMOS APS star tracker can give accurate attitude information and estimated angular rate. The method can be used as the chief attitude determination system design of low-cost satellite without gyros or be used as a backup strategy in the event of gyro failures to enhance the reliability of the attitude determination system.

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：28/0 | 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.