中国科学院机构知识库网格系统: 检索

Microstructure and mechanical properties of directionally solidified Mg-Zn alloy as a biomaterial 期刊论文 OAI收割
MATERIALS SCIENCE AND TECHNOLOGY, 2019, 页码: 8
作者: Jia, Hongmin; Feng, Xiaohui; Yang, Yuansheng

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收藏 | 浏览/下载：19/0 | 提交时间：2021/02/02

Directional solidification biomedical Mg alloy microstructure evolution mechanical property cell-dendrite transition growth rate cooling rate performance requirement

Dietary manganese requirement of juvenile yellow catfish Pelteobagrus fulvidraco, and effects on whole body mineral composition and hepatic intermediary metabolism 期刊论文 OAI收割
AQUACULTURE, 2012, 卷号: 326, 期号: -, 页码: 68-73
作者: Tan, Xiao-Ying; Xie, Ping; Luo, Zhi; Lin, Hei-Zhao; Zhao, Yan-Hong

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收藏 | 浏览/下载：14/0 | 提交时间：2012/09/25

Growth Performance Hepatic Intermediary Metabolism Mineral Composition Pelteobagrus Fulvidraco Manganese Requirement

Lightweight design and analysis of support structure of certain UAV engine (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Electrical Insulating Materials and Electrical Engineering, EIMEE 2012, May 25, 2012 - May 27, 2012, Shenyang, Liaoning, China
Xing X.; Liu B.; Han X.; Jia H.

收藏 | 浏览/下载：31/0 | 提交时间：2013/03/25

Support structure of UAV (Unmanned Aerial Vehicle) engine is the important support for UAV engine playing a support role and bearing extremely complex load so its lightweight strength and dynamic characteristics have a great influence on high performance of UAV. This paper focuses on UAV having the requirement of high performance and stability to the support structure of engine and uses the software of MSC.Patran and MSC.Nastran and topology optimization criterion to lightweight design and analysis the support structure of UAV engine under the premise condition of existing constraints. Then the static strength and modal are analyzed for the result of lightweight design and the strength of the model and dynamic characteristics are verified. (2012) Trans Tech Publications Switzerland.

Design and simulation of CMOS star sensor lens with large relative aperture and wide field (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
Zhong X.; Jin G.

收藏 | 浏览/下载：60/0 | 提交时间：2013/03/25

A 50mm focal length F/1.25 Gaussian type optical system is designed in this paper which has 20field of view. Actual star image adding optical cross-talk effect of CMOS(Complementary Metal Oxide Semiconductor) detector is simulated by non-sequential ray tracing in ZEMAX optical design and analysis software to evaluate its performance. The distortion relative to image spot centriod is introduced and calculated by simulated star images which is less than 0.03% of lens in this paper. Thermal adaptability is discussed by opt-mechanic thermal analysis which shows the RMS spot radius of marginal filed changes less than 0.7m under 10C temperature gradient and changes less than 1m during homogeneous temperature changing from 40C to 40C. The results of analyses and simulations show the design of this lens can achieve the requirement of high precision CMOS star sensor well. 2011 IEEE.

Evaluation of the operating range for ground-based infrared imaging tracking system (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Zhang Z.-D.

收藏 | 浏览/下载：47/0 | 提交时间：2013/03/25

Ground-based infrared imaging tracking system (GIITS) is of great importance for aerial target warning and guard. The operating range is one of the key performance specifications on the other which should be calculated calculate the radiation power received on the detector in order to analysis whether the output signal meets the detection requirements or not analyzed and studied during the whole GIITS design process. The operating range is mostly influenced by a few factors without considering the effect of the background radiation. By improving of the traditional method including atmospheric attenuation a new operating range calculation model of the GIITS was established based on two requirements. One is that the image size of observed target should meet the requirement of the processor signal extraction. The number of the pixel occupied by target image should be more than 9. The other is that the signal noise ratio (SNR) of the GIITS should not be less than 5 to meet the requirements of the target detection probability and spatial frequency. The SNR calculation equation in form of energy is deduced and the radiation characteristic of the observed target and background are analyzed. When evaluate the operating range of the GIITS using the new method the performance of GIITS and feature of target and background. This paper firstly makes analysis and summarization on the definite localizations of the traditional operating range equation of the GIITS. The localizations are mainly in two aspects. On one hand we should successively calculate two operating range values according to two requirements mentioned above and choose the minimum value as the analytic result. In the end the dispersion of the image and the effect of image dispersion are not considered in the traditional method an evaluation of operating range for fighter aircraft is accomplished as an example. The influence factors in every aspect on operating range were explored by the calculated result. The new operating range calculation model provides the theoretical basis for the design and applications as well as the comprehensive evaluation of a GIITS. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

The stability design and realization of airborne platform based on TMS320F2812 (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011, August 19, 2011 - August 22, 2011, Jilin, China
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：40/0 | 提交时间：2013/03/25

Airborne electro-optical stable platform can isolate movement and vibration of the airframe stabilizes the optic axis of the photoelectic detector realize the observation and tracking for the object. It has comprehensive application value in army and cicil field. Most of present airborne platforms are analogic control system digital control system can improve the system general performance digital control is the development direction of platform systems. In view of the requirements of isolating disturbances and stabilizing optical axis of high-precision photoelectric guidance system a three-axis stabilized platform system centering on the rate gyro was designed. The disturbance-isolation theory of the stabilized platform was analyzed and the control structure including multiple closed-loops was designed. At last a controller of the servo system based on TMS320F2812 DSP has been designed. Experiment results meet the technical index and precision requirement and illustrate the practicability and effectiveness of the scheme. 2011 IEEE.

High precision test method for dynamic imaging of space camera (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE International Conference on Advanced Computer Control, ICACC 2010, March 27, 2010 - March 29, 2010, 445 Hoes Lane - P.O.Box 1331, Piscataway, NJ 08855-1331, United States
作者: Jin L.-X.; Zhang K.; Zhang K.; Zhang K.; Zhang K.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

A test method for dynamic imaging of space TDICCD (Time Delay and Integration Charge Coupled Devices) camera was presented in this paper. The test method adopted the PLL (Phase Locked Loop) technology and CMAC (Cerebella Model Articulation Controller) friction compensation as control strategy. Furthermore According to this method a test system for dynamic imaging of space TDICCD camera was designed and implemented. The system simulated the movement of the ground objects relative to the space aerocraft to validate the capability of image speed match and the dynamic imaging quality of TDICCD camera. The design adopted a precision turntable and a drift turntable to simulate the movement around the earth and the drift motion in different latitude due to the rotation of earth of the aerocraft. The turntables were drived by permanent magnet torque motor which was powered by PWM (Pulse Width Modulation). The system adopted DSP (Digital Signal Processor) as the control core and reached a very high performance. The experimental results showed that the steady speed error was better than 0.01 % and the instantaneous speed error reached 0.0267%. The precision of the test system designed met the requirement for dynamic imaging of TDICCD camera. 2010 IEEE.

The design of high-speed optical fiber communication system based on PCI bus (EI CONFERENCE) 会议论文 OAI收割
2010 2nd IEEE International Conference on Advanced Management Science, ICAMS 2010, July 9, 2010 - July 11, 2010, Chengdu, China
作者: Zhang L.-G.; Zhang L.-G.; He X.

收藏 | 浏览/下载：53/0 | 提交时间：2013/03/25

In order to increase the transmission distance and reduce noise effectively a communication system with the optical fiber interface is developed in this paper. In the system the PCI bus is adopted as the connection bus between the underlying optical fiber transceiver module circuitry and host computer using the WDM driver. The FPGA is the core logic of the whole system responsible for data transmission and timing logic control. The module structure and the design method of the PCI bus the principle and the design of optical interface module and the bottom-driven development are described in this paper. The experiment results show that the system has basically meet requirement targets. It can achieve the maximum transfer rate of 40MBps when running in the DMA mode. With long transmission distance strong antiinterference and high scalability this system has stable and reliable performance. 2010 IEEE.

The application of TMS320c64x DSP assembly language in correlation tracking algorithms (EI CONFERENCE) 会议论文 OAI收割
2010 3rd International Congress on Image and Signal Processing, CISP 2010, October 16, 2010 - October 18, 2010, Yantai, China
Huang D.; Wu Z.; Liang M.; Dong Y.; Peng T.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

In order to improve the real-time performance of the conventional correlation tracking algorithm based on full search method for its huge computation amount and vast correlation matching times in the process of searching an optimal matching position a method of combining the TMS320C64x DSP assembly language and software pipelining is proposed to realize template matching which costs the most time of the algorithm. Choose high performance DSP chip TMS320DM642 as the core processor of the hardware platform and schedule each one of the instruction in the algorithm to maximize performance using the instruction-level parallelism of the DSP. The experimental results indicate the time of template image matching implemented in assembly language has decreased from 49.36ms to 0.62ms. It is concluded that the correlation tracking adopting proposed method can meet the real-time and stability requirement of the target tracking. 2010 IEEE.

Storage and compression design of high speed CCD (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, November 19, 2008 - November 21, 2008, Chengdu, China
Cai X.; Zhai L. P.

收藏 | 浏览/下载：57/0 | 提交时间：2013/03/25

In current field of CCD measurement large area and high resolution CCD is used to obtain big measurement image so that speed and capacity of CCD requires high performance of later storage and process system. The paper discusses how to use SCSI hard disk to construct storage system and use DSPs and FPGA to realize image compression. As for storage subsystem Because CCD is divided into multiplex output SCSI array is used in RAID0 way. The storage system is composed of high speed buffer DMA controller control MCU SCSI protocol controller and SCSI hard disk. As for compression subsystem according to requirement of communication and monitor system the output is fixed resolution image and analog PAL signal. The compression means is JPEG2000 standard in which 9/7 wavelets in lifting format is used. 2 DSPs and FPGA are used to compose parallel compression system. The system is composed of FPGA pre-processing module DSP compression module video decoder module data buffer module and communication module. Firstly discrete wavelet transform and quantization is realized in FPGA. Secondly entropy coding and stream adaption is realized in DSPs. Last analog PAL signal is output by Video decoder. Data buffer is realized in synchronous dual-port RAM and state of subsystem is transfer to controller. Through subjective and objective evaluation the storage and compression system satisfies the requirement of system. 2009 SPIE.