中国科学院机构知识库网格系统: 检索

Communication synchronization in wireless optical link (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Control Engineering and Communication Technology, ICCECT 2012, December 7, 2012 - December 9, 2012, Shenyang, Liaoning, China
作者: Guo J.; Guo J.; Wang H.; Wang H.; Wang H.

收藏 | 浏览/下载：31/0 | 提交时间：2013/03/25

An FPGA based transceiving synchronization method is demonstrated for Free Space Optical (FSO) communication system which is discussed separately as the transmitting protocol and the receiving protocol. During the discussion of these two parts the co-operation of them is also discussed. The transmitting protocol interfaces the outer input data with a parallel port buffers the input data encodes the input data stream serializes the parallel data and outputs the serialized data. It also has an output management unit to manage the activity of each part of the transmitting protocol. The receiving protocol filters and synchronizes the input serial data stream parallels the serial data stream decodes the input data checks received error handles transmission exception and interfaces the outer receiver with a parallel port. The entire transceiving protocol could be programmed into a single FPGA chip to improve system integrity and reduce the system cost. The presented protocol could be taken as "protocol transparent" for outer interfaces meaning that when interfacing the presented system to an outer system users don't have to consider what protocol the outer system transceiving data stream is under for example the TCP/IP protocol or anything else in the case that its I/O interface is a parallel port. Simulation and final experiment prove that the protocol presented is a working solution at a certain bit rate scale. 2012 IEEE.

Physical layer design for free space optical communication (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Control Engineering and Communication Technology, ICCECT 2012, December 7, 2012 - December 9, 2012, Shenyang, Liaoning, China
作者: Wang H.; Zhang Q.; Guo J.; Guo J.; Wang H.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

A small size Free Space Optical Communication System is introduced including the hardware and the hardware specified physical layer protocol. In detail the rapid synchronization method to reduce the handshake bandwidth requirement is demonstrated. The hardware of the system includes the laser driver system the signal amplifying and shaping system the data interface system. The hardware specified physical layer protocol is used to interface the outer data serialize and deserialize the data stream check transmission errors and schedule the data transmission. The overall system is a FIFO-like system and the user can use it as if he's operating a FIFO. The system is designed mainly for terrestrial FSO link whose signal channel is the atmosphere. Due to the complex composition and activity of the atmosphere this signal channel brings in great influence on the transmitting laser in it for example the absorption and scattering of the atmosphere molecules and aerosols the scintillation of received laser power caused by the turbulence of the atmosphere all of which results in a much higher Bit Error Rate (BER) of the communication system than wired communication systems leading to frequent resynchronization. In our system the sampling clock is generated locally using multi-phase sampling technique rather than PLLbased clock recovery which helps to rapid synchronization. 2012 IEEE.

A Biological Perspective of The Hypomagnetic Field: From Definition Towards Mechanism 期刊论文 OAI收割
PROGRESS IN BIOCHEMISTRY AND BIOPHYSICS, 2012, 卷号: 39, 期号: 9, 页码: 835-842
Mo WeiChuan; Liu Ying; 刘缨; He Rongqiao; 赫荣乔

收藏 | 浏览/下载：22/0 | 提交时间：2013/12/24

hypomagnetic field outer space biological effect HMF simulation system HMF responding mechanism

Research on lightweight outer baffle for coaxial space camera (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
作者: Zhang L.; Zhang L.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

Stray light is non-imaging light that reach the optical system imaging plane. The non-imaging light can be received by detector if it is not effectively controlled and stray light which directly irradiates on the detector has great influence on the imaging quality. Stray light can be effectively inhibited if the outer baffle of space camera is designed optimally. Carbon fiber composite material is chosen as main material to meet requirements of a coaxial space optical system. The outer baffle should have advantages such as lightweight high stiffness and dimensional stability etc. Using optimization design tools the lightweight outer baffle is designed. And finite element method is used to check the structure. Development and test results show that the outer baffle with a diameter of 620mm and a total length of 1200mm only weighs 7.3kg. And the baffle's natural frequency reaches 88Hz and it can satisfy the requirements of the space camera. 2011 IEEE.

Effects of a hypogeomagnetic field on gravitropism and germination in soybean 期刊论文 OAI收割
ADVANCES IN SPACE RESEARCH, 2011, 卷号: 47, 期号: 9, 页码: 1616-1621
作者: Mo, Wei-chuan; Zhang, Zi-jian; Liu, Ying; Zhai, Guang-jie; Jiang, Yuan-da

收藏 | 浏览/下载：31/0 | 提交时间：2014/12/15

Hypogeomagnetic field Soybean Gravitropism Germination Outer space

Effects of a hypogeomagnetic field on gravitropism and germination in soybean 期刊论文 OAI收割
ADVANCES IN SPACE RESEARCH, 2011, 卷号: 47, 期号: 9, 页码: 1616-1621
Mo, Weichuan; Zhang, Zijian; Liu, Ying; 刘缨; Zhai, Guangjie; Jiang, Yuanda; He, Rongqiao; 赫荣乔

收藏 | 浏览/下载：26/0 | 提交时间：2013/12/25

Hypogeomagnetic field Soybean Gravitropism Germination Outer space

Transceiving protocol designc for a free space optical communication system (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
Hualong W.; Wanxin S.; Zhongbao X.

收藏 | 浏览/下载：58/0 | 提交时间：2013/03/25

A new transceiving protocol is demonstrated for a Free Space Optical (FSO) communication system and it's discussed in two parts: the transmitting protocol and the receiving protocol. During the discussion of these two parts the cooperation of them is also discussed. Different from wired communication an FSO system modulates the data on a narrow beam of laser transmitting through the free space or the atmosphere and the protocol presented in this paper is mainly optimized for terrestrial Free Space Optical links in which the signal channel of the system is mainly the atmosphere. Due to the complex composition and activity of the atmosphere this signal channel brings in great influence on the transmitting laser in it for example the absorption and scattering of the atmosphere molecules and aerosols the scintillation of received laser power caused by the turbulence of the atmosphere all of which results in a much higher Bit Error Rate (BER) of the communication system. Thus in designing a protocol for an FSO system more effort should be taken in the encoding of the data stream the synchronization of the data stream error checking and exception handling. The main function of the transmitting protocol includes interfacing the outer input data with a parallel port buffering the input data encoding the input data stream serializing the parallel data and output the serialized data. It also has an output management unit to manage the activity of each part of the transmitting protocol. The main function of the receiving protocol includes filtering and synchronizing the input serial data stream paralleling the serial data stream decoding the input data error checking exception handling and interfacing the outer receiver with a parallel port. The entire transceiving protocol could be programmed into a single FPGA chip to improve system integrity and reduce the system cost. The presented protocol could be taken as "protocol transparent" for outer interfaces meaning that when interfacing the presented system to an outer system you don't have to consider what protocol the outer system transceiving data stream is under for example the TCP/IP protocol or anything else in the case that its I/O interface is a parallel port. Simulation and final experiment prove that the protocol presented is working fine at a certain bit rate scale. 2009 SPIE.

Early effects of carbon-ion irradiation on murine lymphocytes and thymocytes 期刊论文 OAI收割
ADVANCES IN SPACE RESEARCH, 2007, 卷号: 40, 期号: 4, 页码: 563-567
作者: Xie, Yi; Zhang, Hong; Dang, Bingrong; Bing, Tao; Hao, Jifang

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收藏 | 浏览/下载：26/0 | 提交时间：2010/10/29

(12)c(6+) Heavy Ion Cell Cycle Apoptosis Immunocyte Outer Space Mouse

A new method of image reconstruction with high resolution in X-ray coded aperture imaging (EI CONFERENCE) 会议论文 OAI收割
Laser-Generated, Synchrotron, and Other Laboratory X-Ray and EUV Sources, Optics, and Applications II, August 2, 2005 - August 4, 2005, San Diego, CA, United states
作者: Sun Y.; Sun Y.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

In the processing diagnosis of the inertia confinement fusion (ICF) the ring coded aperture imaging technique is applied in order to gain high space and time resolutions simultaneously. The key of acquiring high spatial resolution is how to obtain a point spread function of an imaging system. The common method is the firsthand projection method which is an approximate one. The x-ray diffraction effect is neglected in the method so the resolution of reconstructed image is decreased. We have derived the point spread function (PSF) of the ring coded aperture from scalar diffraction theory. And the Wiener filter is fabricated on the basis of the PSF. In National Key Laboratory of Laser Fusion at China Academy of Engineering Physics the imaging experiment on the diagnosis of ICF is completed using the ring coded aperture plate with inner diameter d1 = 250m and outer diameter d2 = 260m . The obtained coded image is processed by the Wiener filter which diffractive effect is considered. The processed results have shown that resolution and modulation contrast of acquired image are evidently better than the results obtained by the firsthand projection method.

Semi-insulating gaas grown in outer space 期刊论文 iSwitch采集
Materials science and engineering b-solid state materials for advanced technology, 2000, 卷号: 75, 期号: 2-3, 页码: 134-138
作者: Chen, NF; Zhong, XR; Lin, LY; Xie, X; Zhang, M

收藏 | 浏览/下载：30/0 | 提交时间：2019/05/12

Gaas Outer space Microgravity Integrated circuit