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Study on the atmospheric photochemical reaction of CF_3 radicals using ultraviolet photoelectron and photoionization mass spectrometer

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Science china Chemistry 2008年第4期51卷 316-321页

作者： YAO Li1,2. DU Lin1,2. YIN Shi1,2.& GE MaoFa1 1 beijing National Laboratory for Molecular sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry,{2., beijing 100080, china 2.graduate University of{2., beijing 100080, china 1. beijing National Laboratory for Molecular sciences (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China 2. graduate University of chinese academy of sciences Beijing 100080 China

A study of the atmospheric photochemical reaction of CF3 radical with CO and O2.was performed by using a homemade ultraviolet photoelectron spectrometer-photoionization mass spectrometer (PES- PIMS). The electronic structures and mechanism of ionization and dissociation of CF3OC(O)OOC(O)- OCF3 were investigated. It was indicated that the two bands on the photoelectron spectrum of CF3OC(O)OOC(O)OCF3 are the result of ionization of an electron from a lone pair of oxygen and a fluo- rine lone pair of CF3 group. The outermost electrons reside in the oxygen lone pair. The experimental and theoretical first vertical ionization energy is 13.2. and 13.178 eV, respectively, with the PES and OVGF method. They are in good agreement. The photo ionization and dissociation processes were discussed with the help of theoretical calculations and PES-PIMS experiment. After ionization, the parent ions prefer the dissociation of the C-O bond and giving the fragments CF3OCO+ and CF3+. It demonstrated that the ultraviolet photoelectron and photoionization mass spectrometer could be ap- plied widely in the study of atmospheric photochemical reaction.

关键词： photochemical reaction CF3 radical ultraviolet photoelectron and photoionization mass spectroscopy transient species

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Testing local realism in P → VV decays

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Science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 870-875页

作者： LI JunLi1 & QIAO CongFeng1,2.1Department of Physics,graduate University of chinese academy of sciences,{2. 100049,china 2.heoretical Physics Center for Science Facilities(TPCSF),chinese academy of sciences,{2. 100049,china 1. Department of Physics Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Theoretical Physics Center for Science Facilities (TPCSF) Chinese Academy of Sciences Beijing 100049 China

It was found that the vector meson pair from the pseudoscalar decays can form an entangled *** this work we give out detailed explanations on the polarization correlation of the two entangled vector *** is demonstrated that an experimental test of the Clauser-Horne inequality can be carried out through measuring the azimuthal distribution of four pseudoscalars in the cascade decay ηc→ VV →(PP)(PP),and the measurement of this process is feasible with the current running experiments in tau-charm ***,a brief discussion on the polarization correlation of the two vector mesons from B → VV decays is also presented.

关键词： nonlocality test high energy experiment meson decays

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The establishment of crystal position look-up table for positron emission tomography with block detectors

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Science china(Technological sciences) 2009年第8期52卷 2418-2423页

作者： CHAI Pei1,2.& SHAN BaoCi1 1 Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, chinese academy of sciences, beijing 100049,{2. 2.graduate University of chinese academy of sciences, beijing 100049,{2. Key Laboratory of Nuclear Analytical Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China graduate University of chinese academy of sciences Beijing 100049 China

A method has been developed to establish the crystal position look-up table for positron emission tomography with block detectors. It is based on the principle that the counts in crystal position histogram obey the Gaussian mixture model (GMM). This method has taken full consideration of the characteristics of the GMM and the detector itself. The experimental results have proved that it is simple, reliable, and universal.

关键词： positron emission tomography position look-up table 2.D position histogram

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Contributions of phosphatase and microbial activity to internal phosphorus loading and their relation to lake eutrophication

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Science china Earth sciences 2006年第z1期49卷 102-113页

作者： SONG Chunlei, CAO Xiuyun, LI Jianqiu, LI Qingman, CHEN Guoyuan & ZHOU Yiyong Institute of Hydrobiology, chinese academy of sciences, Wuhan 430072. china {2. school of the chinese academy of sciences, beijing 100039, china 1. Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China 2. graduate school of the chinese academy of sciences Beijing 100039 China

Phosphatase may accelerate the process of lake eutrophication through improving phosphorus bioavailability. This mechanism was studied in three chinese eutrophic shallow lakes (Lake Taihu, Lake Longyang and Lake Lianhua). Phosphatase activity was related to the concentration of soluble reactive phosphorus (SRP) and chlorophyll a. Stability of dissolved phosphatase in reverse micelles may be attributed to molecular size, conformation and active residues of the *** the site with Microcystis bloomed in Lake Taihu, dissolved phosphatase activity was higher and more stable in micelles, SRP concentrations were lower in interstitial water, the contents of different forms of phosphorus and the amounts of aerobic bacteria were lower while respiration efficiency was higher in sediments. Phosphobacteria, both inorganic and organic and other microorganisms were abundant in surface water but rare in sediments. Therefore, internal phosphorus may substantially flux into water column by enzymatic hydrolysis and anaerobic release, together with mobility of bacteria,thereby initiating the bloom. In short, biological mechanism may act in concert with physical and chemical factors to drive the internal phosphorus release and accelerate lake eutrophication.

关键词： dissolved phosphatase, reverse micelle, internal loading, phosphorus form of sediment, microbiology, eutrophication, Microcystis bloom.

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A formula on linear complexity of highest coordinate sequences from maximal periodic sequences over Galois rings

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Progress in Natural Science:Materials International 2006年第9期16卷 998-1001页

作者： HU Lei and SUN Nigang (State Key Laboratory of Information Security, graduate school of{2., beijing 100049, china) [a]State Key Laboratory of Information Security Graduate School of Chinese Academy of Sciences Beijing China

Using a polynomial expression of the highest coordinate map, we deduce an exact formula on the linear complexity of the highest coordinate sequence derived from a maximal periodic sequence over an arbitrary Galois ring of characteristic p2., where p is a prime. This generalizes the known result of Udaya and Siddiqi for the case that the Galois ring is Z4.

关键词： Galois ring highest coordinate sequence linear complexity.

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Recent progress in fingerprint recognition

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Progress in Natural Science:Materials International 2006年第3期16卷 231-240页

作者： TIAN Jie, CHEN Xinjian, ZHANG Yangyang, YANG Xin, HE Yuliang, LI Liang, XIE Weihua and ZHENG Zhipeng (Center for Biometrics and Security Research, Key Laboratory of Complex Systems and Intelligence Science, Institute of Automation, chinese academy of sciences, beijing 100080,{2. graduate school of the chinese academy of sciences, beijing 100080,{2.) [a]Center for Biometrics and Security Research Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Beijing China [b]graduate school of the{2. Beijing China

Fingerprint recognition has been increasingly used to realize personal identification in civilian' s daily life, such as ID card, fingerprints hard disk and so on. Great improvement has been achieved in the on-line fingerprint sensing technology and automatic fingerprint recognition algorithms. Various fingerprint recognition techniques, including fingerprint acquisition, classification, enhancement and matching, are highly improved. This paper overviews recent advances in fingerprint recognition and summarizes the algorithm proposed for every step with special focuses on the enhancement of low-quality fingerprints and the matching of the distorted fingerprint images. Both issues are believed to be significant and challenging tasks. In addition, we also discuss the common evaluation for the fingerprint recognition algorithm of the Fingerprint Verification Competition 2.04 (FVC2.04) and the Fingerprint Vendor Technology Evaluation 2.03 (FpVTE2.03), based on which we could measure the performance of the recognition algorithm objectively and uniformly.

关键词： biometrics fingerprint enhancement matching minutia image registration similarity measures.

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Properties and applications of cold supersonic gas jet

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Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 709-715页

作者： ZHANG Shaofeng1,2.MA Xinwen1,2.LIU Huiping2.LI Bin1,2.& ZHU Xiaolong1,2.1. Institute of Modern Physics,chinese academy of {2.,Lanzhou 730000,china 2. graduate University of chinese academy of sciences,beijing 100049,china 1. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China 2. graduate University of chinese academy of sciences Beijing 100049 China

By analyzing the formation mechanism of a supersonic gas jet,a set of equations which describe the atomic beam properties were established. The influence of initial temperature,initial pressure,background gas pressure and pumping speed was discussed in detail. A simulation program was developed based on the equations,and the results under different initial conditions were obtained. The results are in good agreement with the experimental data,and suggest that,in order to get much smaller transverse momentum in collision experiments,it is necessary to lower the initial temperature and the initial pressure of the supersonic gas jet,together with increasing the pumping speed. These results are very instructive for construction of a new generation of cold supersonic gas jets.

关键词： cold supersonic gas jet,zone of silence,nozzle,skimmer.

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SAR IMAGING SIMULATION OF HORIZONTAL FULLY TWO-DIMENSIONAL INTERNAL WAVES

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Journal of Hydrodynamics 2006年第3期18卷 294-302页

作者： SHEN Hui HE Yi-Jun Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China graduate school of the{2. Beijing 100039 China

Based on the research of Lynett and Liu, a new horizontal fully two-dimensional internal wave propagation model with rotation effect was deduced, which can be used to simulate the characteristics of internal waves in a horizontal fully two-dimensional plane. By combining the imaging mechanism of Synthetic Aperture Radar（SAR）, a simulation procedure was fatherly acquired, which can simulate the propagation characteristics of oceanic internal waves into SAR images. In order to evaluate the validity of the proposed simulation procedure, case studies are performed in South china Sea and results from simulation procedure are analyzed in detail. A very good consistency was found between the simulation results and satellite images. The proposed simulation procedure will be a possible foundation for the quantitative interpretation of internal waves from fully two-dimensional satellite images.

关键词： oceanic internal waves imaging simulation,Synthetic Aperture Radar (SAR)

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Aridity/humidity status of land surface in china during the last three decades

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Science china Earth sciences 2005年第9期48卷 1510-1518页

作者： WU Shaohong1, YIN Yunhe1,2. ZHENG Du1 & YANG Qinye1 1. Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences (CAS), {2. 100101, china 2. graduate school of the CAS, {2. 100039, china 1. Institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences (CAS) 100101 Beijing China 2. graduate school of the CAS 100039 Beijing China

To clarify aridity/humidity status of land surface is helpful for studying environmental background and regional differences, seeking causes of environmental change, and providing a scientific basis for researches on climate change in the future. In this paper, the authors calcu- lated potential evapotranspiration of china using data from 616 meteorological stations during the period of 1971―2.00 with the Penman-Monteith model recommanded by FAO in 1998. Vy- sothkii’s model was used to calculate aridity/humidity index. Then the calculated results of sta- tions were interpolated to land surface using ArcGIS. Results show that the annual average po- tential evapotranspiration is 400―1500 mm in the whole country, 600―800 mm in most parts of it; and 350―1400 mm in growing season (April―Octobor), which is nearly 2.0 mm less than the annual average. According to the aridity/humidity indexes of 1.0, 1.5 and 4.0, the aridity/humidity status is categorized to four types, namely, humid, subhumid, semiarid and arid. A majority of stations (76%) are more humid in growing season than the annual average. Results of com- prisons between the distribution map of aridity/humidity index with that of precipitation and vegetation indicate a good consistence of aridity/humidity status with natural environment. Therefore potential evapotranspiration calculated with modified FAO’s Penman-Monteith model in combination with aridity/humidity index that considers water balance can more reasonably explain the actual land surface aridity/humidity status of china.

关键词： potential evapotranspiration, aridity/humidity status, land surface, regional differences, Penman-Monteith.

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A cumulant-based parameter estimation algorithm for near-field sources

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Progress in Natural Science:Materials International 2007年第8期17卷 900-905页

作者： Liang Junli~(1,2.) Yang Shuyuan~(1,2. Zhang Junying~3 (1.Institute of Acoustics,chinese academy of {2.,beijing 100080,china 2.graduate school,chinese academy of {2.,beijing 100039,china 3.National Laboratory of Radar Signal Processing,Xidian University,Xi'an 710071,china) [a]Institute of Acoustics Chinese Academy of Sciences Beijing China [b]graduate school Chinese Academy of Sciences Beijing China [c]National Laboratary of Radar Signal Processing Xidian University Xi'an China

To efficiently use the array aperture and avoid the complicated parameter pairing computation,this paper proposes a new cumulant-based algorithm for localizing near-field narrowband ***,this algorithm proposes a symmetric uniform linear ar- ray (ULA),and constructs three cumulant matrices by using the fourth-order cumulants of some properly chosen sensor outputs;second- ly,unlike the conventional parallel factor (PARAFAC) analysis models in data or subspace domain,it forms a three-way array (TWA) in the fourth-order cumulant domain using the three matrices,and analyzes the uniqueness of its low-rank decomposition;thirdly,it jointly estimates the frequency,the direction-of-arrival (DOA),and the range of each near-field source from the matrices via the low-rank de- composition of the *** simulation results are presented to validate the performance of our proposed method.

关键词： array signal processing localization cumulant parallel factor (PARAFAC) analysis three-way array (TWA)

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