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chinese Physics B 2013年第7期22卷 533-541页

作者：肖啸鲁远甫于峰崎金雷 shenzhen institutes of {2. Technology Chinese Academy of SciencesShenzhen 518055China chinese University of Hong Kong

A 1550-nm linearly tunable continuous wave （CW） single-mode external cavity diode laser （ECDL） based on a singlecavity all-dielectric thin-film Fabry-Pérot filter （s-AFPF） is proposed and realized in this paper. Its internal optical components as well as their operation mechanisms are introduced first, and then its longitudinal mode output characteristic is theoretically analyzed. Afterwards, we set up the experimental platform for the output characteristic measurement of this tunable ECDL; under different experimental conditions, we execute accurate and real-time measurements for the output central wavelength, output optical power, output longitudinal mode distribution, and the line-width of the tunable ECDL in its tuning process. By summing up the optimal experimental condition from the measured data, we obtain the optimal tunable ECDL relevant parameters： the tunable ECDL has a linear mode-hop-free wavelength tuning region of 1547.2.3 nm-1552.42. nm, a stable output optical power in the range of 40 μW-50 μW, and a stable output longitudinal mode distribution of a single longitudinal mode with a line-width in the range of 100 MHz-150 MHz. This tunable ECDL can be used in environmental gas monitoring, atomic and molecular laser spectroscopy research, precise measurements, and so on.

关键词： thin-film optical properties tunable external cavity diode laser laser spectroscopy

Optical characteristics and environmental pollutants detection of porous silicon microcavities

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Science china Chemistry 2011年第8期54卷 1348-1356页

作者： HUANG JianFeng, LI Sha, CHEN QingWei & CAI LinTao CAS Key Laboratory of Health Informatics shenzhen Key Laboratory of Cancer Nanotechnology Institute of Biomedical and Health Engineering, shenzhen Institute of {2. Technology, chinese academy of sciences, shenzhen 518055, china 1. CAS Key Laboratory of Health Informatics shenzhen Key Laboratory of Cancer Nanotechnology Institute of Biomedical and Health Engineering Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China

Porous silicon microcavities (PSM) optical crystals consisting of a Fabry-Perot microcavity embedded between two distributed Bragg reflectors have been fabricated by electrochemical etching. Scanning electron microscopy (SEM) clearly depicted their physical sandwich construction. The optical feature of the PSM structure was tuned by varying the anodization parameters. Through proper thermal oxidation and surface chemical modifications, the resulting structures were employed as optical sensors for the detection of environmental pollutants including volatile organic vapors (i.e. acetonitrile, toluene, cyclohexane, chloroform, acetone and ethanol) and interior decoration gases (i.e. toluene, ammonia and formaldehyde). Fourier transform infrared spectroscopy (FTIR) spectra confirmed the effective thermal annealing and surface modification chemistry, and the sensing process was accompanied by recording the modified structures' optical responses when exposed to target analytes. The PSM optical sensors showed good stability, sensitivity and selectivity, implying promising applications in gas sensing and en- vironmental monitoring.

关键词： porous silicon microcavity optical sensor thermal oxidation surface modification environmental pollutants detection

Perceptual video hashing robust against geometric distortions

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Science china(Information sciences) 2012年第7期55卷 1520-1527页

作者： XIANG ShiJun 1,4 ,YANG JianQuan 2.& HUANG JiWu 3 1 School of Information Science and Technology,Jinan University,Guangzhou 510632.china 2.shenzhen {2. of advanced Technology,chinese academy of sciences,shenzhen 518055,china 3 School of Information Science and Technology,Sun Yat-sen University,Guangzhou 5102.5,china 4 State Key Laboratory of Information Security,Institute of Software,chinese academy of sciences,Beijing 100049,china 1. School of Information Science and Technology Jinan University Guangzhou 510632 China4. State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing 100049 China2. Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China3. School of Information Science and Technology Sun Yat-sen University Guangzhou 510275 China

In this paper,we propose a robust perceptual hashing algorithm by using video luminance histogram in *** underlying robustness principles are based on three main aspects:1) Since the histogram is independent of position of a pixel,the algorithm is resistant to geometric deformations; 2. the hash is extracted from the spatial Gaussian-filtering low-frequency component for those common video processing operations such as noise corruption,low-pass filtering,lossy compression,etc.; 3) a temporal Gaussian-filtering operation is designed so that the hash is resistant to temporal desynchronization operations,such as frame rate change and *** a result,the hash function is robust to common geometric distortions and video processing *** results show that the proposed hashing strategy can provide satisfactory robustness and uniqueness.

关键词： video hashing geometric distortion histogram Gaussian filtering

Antisense expression of a rice cellular apoptosis susceptibility gene (OsCAS} alters the height of transgenic rice

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Progress in Natural Science:Materials International 2007年第1期17卷 39-43页

作者： XU Chunxiao and HE Chaozu ( National Key Laboratory of Plant Genomics, Institute of Microbiology, chinese academy of sciences, Beijing 100080, china Graduate University of chinese academy of sciences, Beijing 100039, china shenzhen Laboratory of Superhybrid Rice Research, Graduate School at shenzhen, Tsinghua University, shenzhen 518055, china) [a]National Key Laboratory of Plant Genomics Institute of Microbiology Chinese Academy of Sciences Beijing China [b]Graduate University of chinese academy of sciences Beijing China

Cellular apoptosis susceptibility (CAS) gene plays important roles in mitosis, development and export of importin a from the nucleus, but its function in plant is unknown. In this study, a rice CAS ortholog (OsCAS), which encodes a predicted protein of 983 amino acids with 62. similarity to human CAS, was identified. DNA gel blot analysis revealed a single copy of OsCAS in the rice genome. A 973 bp fragment at the 3' end of OsCAS cDNA was cloned from rice cDNA library and transferred into rice in the antisense direction under the control of CaMV 35S promoter via Agrobacterium-mediated transformation method, 105 transgenic lines were obtained. Expression of OsCAS was suppressed in the antisense transgenic lines as revealed by semi-quantitative RT-PCR. The antisense transgenic lines showed dwarf phenotypes. The results indicated that OsCAS was involved in culm development of rice.

关键词： antisense dwarf ortholog OsCAS rice.

A flexible framework for HMM based noise robust speech recognition using generalized parametric space polynomial regression

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Science china(Information sciences) 2011年第12期54卷 2501-2511页

作者： CHENG Ning 1 , LIU XunYing 1,2.& WANG Lan 1 1 shenzhen institutes of {2. Technology, chinese academy of sciences/The chinese University of Hong Kong, Hong Kong, china 2.Cambridge University Engineering Department, Cambridge CB2.1PZ, UK 1. shenzhen institutes of {2. Technology Chinese Academy of Sciences/The Chinese University of Hong Kong Hong Kong China2. Cambridge University Engineering Department Cambridge CB2 1PZ UK

Handling variable, non-stationary ambient noise is a challenging task for automatic speech recognition (ASR) systems. To address this issue, multi-style, noise condition independent (CI) model training using speech data collected in diverse noise environments, or uncertainty decoding techniques can be used. An alternative approach is to explicitly approximate the continuous trajectory of Gaussian component mean and variance parameters against the varying noise level, for example, using variable parameter hidden Markov model (VP-HMM). This paper investigates a more generalized form of variable parameter HMMs (GVP-HMM). In addition to Gaussian component means and variances, it can also provide a more compact trajectory modeling for tied linear transformations. An alternative noise condition dependent (CD) training algorithm is also proposed to handle the bias to training noise condition distribution. Consistent error rate gains were obtained over conventional VP-HMM mean and variance only trajectory modeling on a media vocabulary Mandarin chinese in-car navigation command recognition task.

关键词： non-stationary noise generalized variable parameter HMM noise robust speech recognition

Wind vector retrieval using dual polarization imagery of ASAR

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Progress in Natural Science:Materials International 2006年第11期16卷 1183-1187页

作者： SONG Guiting~ 1,2., HOU Yijun~1** and QI Peng~1(1. Institute of Oceanology, chinese academy of sciences, Qingdao 2.6071, china 2. Graduate School, chinese academy of sciences, Beijing 100039, china) [a]Institute of Oceanology Chinese Academy of Science Qingdao China [b]Graduate School Chinese Academy of Sciences Beijing China

A new algorithm for retrieving wind vector using dual polarization imagery of advanced synthetic aperture radar (ASAR) is developed and tested. Based on the combination of co-polarization and cross-polarization, this new algorithm effectively eliminates the 180° ambiguity which occurs when using single imagery of the ASAR to retrieve wind vector. This algorithm also solves the problem that the retrieval results will break down on very small spatial scales. The results retrieved from dual polarization imagery of ASAR show that the wind speed and direction are in agreement with the data from Quikscat and buoy measurements. The root mean square errors of wind direction and speed between the retrieved results and data from Quikscat are 2.2.° and 0.53 m/s, respectively. Comparisons between the new method and the traditional method show that the new methods fit the buoy data and Quikscat data a little better than the traditional method in this image.

关键词： wind vector retrieval ASAR dual polarization.

Heterotrophic bacteria of the Dapeng Bay in the South china Sea: community structure,abundance,and the relationships of culturablity with environmental factors

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Acta Oceanologica Sinica 2010年第4期29卷 88-97页

作者： JIANG Fajun HU Zhangli HU Chaoqun South china Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China Guangxi academy of sciences Nanning 530007 China College of Life sciences Shenzhen University Shenzhen 518060 China

The community composition,abundance and culturablity of heterotrophic bacterioplankton in the Dapeng Bay of the South china Sea were investigated by morphological method,bacterial cultivation and biochemical methods over an annual *** and Pseudomonas were the predominant genera among the Gram-negative *** bacterioplankton abundance fluctuated from 2.07×10 8 to 2.44×10 9 cells/dm 3 ,and culturable bacteria abundance ranged between 0.1×10 6 and 16.07×10 6 CFU/dm 3 .The Culturablity of heterotrophic bacteria ranged between 0.01% and 1.31%.The relationship between bacterial culturablity and the environmental factors was also studied in different sites of the Dapeng *** the bay,a significantly positive relationship was evidenced between bacterial culturability and temperature,meanswhile bacterial culturability was significantly inversely related with *** positive relationship was shown at the central bay while a negative relationship was observed at the bay mouth and there was no significant correlation at top bay between bacterial culturablity and chlorophyll a of sea water.A positive relationship was found between culturability and DIN all the bay,but DIP showed a significantly negative relationship with bacterial culturability only at the mouth of the bay.

关键词： heterotrophic bacteria culturable bacteria culturablity environmental factors

Some key technics of drop tower experiment device of National Microgravity Laboratory (china) (NMLC)

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Science china(Technological sciences) 2005年第3期48卷 305-316页

作者： ZHANG Xiaoqian 1 , YUAN Longgen 1 , WU Wendong 1 , TIAN Lanqiao 2.& YAO Kangzhuang 2.1. Institute of Engineering Thermophysics, chinese academy of sciences, Beijing 100080, china 2. Institute of Mechanics, chinese academy of sciences, Beijing 100080, china 1. Institute of Engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. Institute of Mechanics Chinese Academy of Sciences 100080 Beijing China

Drop tower is an important ground based facility for microgravity science experiment. The technical performances of the drop tower NMLC are advanced compared with similar facilities in the US, Germany and Japan. The main components such as drop capsule, deceleration devices, release mechanism present its advantages and creativities.

关键词： drop tower facility,drop capsule,deceleration devices,release mechanism.

Numerical simulation of Meiyu front and the diagnosis of moist vorticity vector

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Progress in Natural Science:Materials International 2007年第11期17卷 1341-1347页

作者： Ping Fan1,2.and Luo Zhexian2.1. Institute of Atmospheric Physics, chinese academy of sciences, Beijing 10002., china 2. Nanjing University of Information {2. & Technology, Nanjing 2.0044, china) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Nanjing University of Information sciences & Technology Nanjing 210044 China

Moist vorticity vector is introduced to study the development and evolution of mesoscale convective vortex (MCV) in the Meiyu front precipitation with the advanced Regional Predication System (ARPS). In this study, the heavy rainfall is simulated to investigate the genesis, development and dissipation of middle scale convective vortex, which occurred from 0000 UTC 3 July to 12.0 UTC 5 July over the Jianghuai River valley. Moist vorticity vector (MVV) has zonal, radial and vertical components in its 3D spatial distribution. The simulation shows that the vertical component of moist vorticity vector well demonstrates the spatial distribution characteristics of middle scale convective vortex, especially in the process of Meiyu front precipitation. Diagnosis upon zonal, radial averaged and mass-integrated quantities of MVV shows that its vertical component and the surface precipitating ratio are in phase with a correlation coefficient of 0.68, indicating that the vertical component of MVV is closely associated with the Meiyu front precipitation. In addition, the tendency of the vertical component of MVV is mainly determined by the interaction between the vorticity and the zonal and radial gradient of condensational or depositional heating.

关键词： moist vorticity vector mesoscale convective vortex Meiyu front precipitation

Cure of experimental botulism and antibotulismic effect of toosendanin

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Acta Pharmacologica Sinica 2004年第6期25卷 137-146页

作者： Yu-liang SHI2. Zhong-feng WANG Key laboratory of Neurobiology, Shanghai institutes for Biological sciences, {2. academy ofScience, Shanghai2.0031, china Key laboratory of Neurobiology Shanghai Institutes for Biological Sciences Chinese Academy of Science Shanghai 200031 Chin

Botulinum neurotoxins (BoNTs), a group of bacterial proteins that comprise a light chain disulfide linked a heavy chain, are the most lethal biotoxins known to mankind. By inhibiting neurotransmitter release, BoNTs cause severe neuroparalytic disease, botulism. A series of important findings in the past 10 years which displayed the molecular targets of BoNTs and hence proposed a four-step action mechanism to explain BoNT intoxication greatly advanced the study of antibotulismic drug. In this article, we reviewed these progresses and anti-botulismic compounds found in recent years. These compounds function due to their facilitation on neurotransmitter release or to their interference on the binding, internalization, translocation, and endopeptidase activity of the toxins. Toosendanin is a triterpenoid derivative extracted from a digestive tract-parasiticide in chinese traditional medicine. chinese scientists have found that the compound is a selective prejunctional blocker. In spite of sharing some similar action with BoNT, toosendanin can protect botulism animals that have been administrated with lethal doses of BoNT/A or BoNT/B for several hours from death and make them restore normal activity. The neuromuscular junction preparations isolated from the rats that have been injected with toosendanin tolerate BoNT/A challenge. Toosendanin seems to have no effect on endopeptidase activity of BoNT, but blocks the toxin approach to its enzymatic substrate.

关键词： toosendanin botulinum toxins botulism synaptic transmission neurotransmitter triterpene chinese traditional medicine