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Cloning and sequencing of nifBHDKENX genes of Paenibacillus massiliensis T7 and its nif promoter analysis

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Science China(Life Sciences) 2006年第2期49卷 115-122页

作者： ZHAO Hongxin1,2,3. XIE Baoen2 & CHEN Sanfeng1,2 1. State key Laboratory for Agrobiotechnology and Biological School, China Agricultural university, beijing 100094, China 2. key Laboratory for Agro-Microbial Resource and Application of Agriculture Ministry, China Agricultural university, beijing 100094, China 3. Chemical and Biological School, ShenYang normal university, Shenyang 11003., China State key Laboratory for Agrobiotechnology and Biological School China Agricultural University Beijing China key Laboratory for Agro-Microbial Resource and Application of Agriculture Ministry China Agricultural University Beijing China Chemical and Biological School ShenYang Normal University Shenyang China

A 3.4 bp of nifH fragment was PCR amplified from Paenibacillus massiliensis T7 using the universal degenerate primers. The PCR-amplified nifH fragment was labeled with DIG; then used as a probe in Southern blot analysis. Southern blot result showed that there were two positive signals, indicating that there might be two copies of nifH in P. massiliensis T7. A total of 10254 bp DNA sequence containing purD; nifBHDKENX was obtained by five rounds of inverse-PCR amplification. The predicted proteins of nifBHDKENX had high homology with those from other nitrogen-fixing bacteria. Only one putative σ[54]-dependent promoter sequence was detected upstream of the nifB gene; nifBHDKENX were likely to be organized in one operon. Assays of β-galactosidase activity of P. massiliensis T7PB carrying a nifB-lacZ fusion under different concentrations of NH4 [+]; O2 showed that the expression of nifB-lacZ was strongly inhibited by O2.

关键词： Paenibacillus massiliensis T7, nifBHDKENX, nifB-lacZ, inverse-PCR.

Isomerization of B_6,B_6^- and B_6^+ clusters

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Science China Chemistry 2010年第1期53卷 202-209页

作者： WEI GongMin1,PU ZhiFeng2,ZOU Rong3.LI GuoLiang2,3.& LUO Qiong2,3.1Department of Physics,Capital normal university,beijing 100048,China 2State {3. Laboratory of Explosion Science and Technology beijing Institute of Technology,beijing 100081,China 3.enter for Computational Quantum Chemistry,South China normal university,Guangzhou 51063.,China Department of Physics Capital Normal University Beijing China State key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing China Center for Computational Quantum Chemistry South China Normal University Guangzhou China

The interconversions between isomers with the same spin multiplicity of neutral B6 and charged B6-and B6+ clusters have been investigated at the B3.YP/6-3.1+G level of theory,including determination of the minimum energy pathways with transition states connecting the corresponding reactants and *** dynamic calculations,26 isomers were optimized,including 11 novel *** order to further refine the energies,single-point B3.YP/6-3.1+G(3.f) calculations were carried out on the corresponding B3.YP/6-3.1+G geometries of all isomers of B6,B6-and B6+ and the corresponding isomerization transition *** stability of each isomer of B6(singlet and triplet states),B6-(doublet state) and B6+(doublet state) was analyzed from both thermodynamic and dynamic viewpoints.

关键词： B6 transition state intrinsic reaction coordinate barrier height

Matrix calculation of high-dimensional cross product and its application in automatic recognition of the endmembers of hyperspectral imagary

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Science China(Information Sciences) 2011年第1期54卷 197-203页

作者： GENG XiuRui1,ZHAO YongChao1,LIU SuHong2 & WANG FuXiang3.1key Laboratory of Technology in Geo-spatial Information Processing and Application System, Institute of Electronics,Chinese Academy of Sciences,beijing 100080,China 2State key Laboratory of Remote Sensing Science,Jointly Sponsored by beijing normal university and the Institute of Remote Sensing Applications of Chinese Academy of Sciences, School of geography,beijing normal university,beijing 100875,China 3.chool of Electronics and Information Engineering,Beihang university,beijing 100191,China key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences State key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and the Instit

This paper gives the definition of the high-dimensional cross product and its calculation by extending the 3.D cross product definition into the high-dimensional vector *** on the properties of the cross product,the volume variance index(VVI)is proposed to be used in extracting automatically the endmembers of the hypherspectral imagery which eliminates the shortcoming of the traditional method of using simplex only where the extraction results were easily impacted by the abnormal pixels.A case study of endmembers extraction experiment using the VVI method with the AVIRIS data for Cuprite has shown a very good result.

关键词： endmember simplex hyperspectral imagery cross product

A distributed hydrological model with its application to the Jinghe watershed in the Yellow River Basin

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Science China(Technological Sciences) 2004年第z1期47卷 60-71页

作者： WANG Zhonggen1, ZHENG Hongxing1, LIU Changming1, , WU Xianfeng2 2 & ZHAO Weimin3.1. key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, China 2. Institute of Environmental Science, beijing {3. university, beijing 100875, China 3. Water Resources Conservation Committee of Yellow River, Zhengzhou 450003. China key Laboratory of Water Cycle & Related Land Surface Processes Institute of Geographic Science and Natural Resources Research Chinese Academy of Sciences Institute of Environmental Science Beijing Normal University

For the purpose of water resources management in the Yellow River Basin with highly spatial difference, a daily distributed hydrological model was proposed, of which the determination of spatially-distributed parameters and model inputs processing were performed by means of GIS/RS. In the model, the computation of runoff yield was based on the topography index method and flow routing was modeled by Maskingum method. The operation of the model is followed by means of “command structure” technique based upon the topography of river network. A case study using the model was conducted for the Jinghe watershed, which locates at the middle Yellow River Basin. The simulation of the hydrological processes in 1996 has shown that water quantity balance errors were less than 5% and the Nash-Sutcliffe coefficient arrived at 0.7, indicating that the model structure is justifiable, and the precision of the model can satisfy the purpose of water resources management.

关键词： distributed hydrological model, structure and equation, GIS and RS, Jinghe Basin, Yellow River Basin.

Spatio-temporal pattern analysis of single-trial EEG signals recorded during visual object recognition

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Science China(Information Sciences) 2011年第12期54卷 2519-2527页

作者： WANG ChangMing 1 , HU XiaoPing 3., YAO Li 1,2 , XIONG Shi 2 & ZHANG JiaCai 2 1 National key Laboratory of Cognitive Neuroscience and Learning, beijing normal {3., beijing 100875, China 2 College of Information Science and Technology, beijing normal {3., beijing 100875, China 3.Biomedical Imaging Technology Center, Emory {3./Georgia Institute of Technology, Atlanta 3.3.2, USA National key Laboratory of Cognitive Neuroscience and Learning Beijing Normal University College of Information Science and Technology Beijing Normal University

Object discrimination is a fundamental cognitive function for human brains. In this study, we utilized an analysis approach for single-trial electroencephalography (EEG) to analyze the spatio-temporal activation patterns of visual objects processing in human brains, and attempted to apply it to discriminate different visual objects. The spatial patterns were respectively extracted from scalp EEG and the reconstructed cortical sources, while the experiment participants were perceiving 4 different categories of visual objects (faces, buildings, cats and cars). By classifying the patterns extracted from single-trial EEG, the presented visual objects could be discriminated by a computer, and the classification accuracies may provide a quantitative index to evaluate the spatial differences of the brain activations related to different visual objects. Our results demonstrated that the spatial patterns on both the scalp and the sources levels resulted in higher classification accuracies than chance rate. We also examined the classification results using temporally non-overlapping time intervals of different event-related potential (ERP) components. The temporal changes of classification accuracies may reflect the temporal distribution of the discriminative information in the EEG responses. The present pattern extraction and classification methods may compose a computational model for single-trial EEG data analysis in investigations of the spatio-temporal activation patterns for object recognition. These spatio-temporal patterns in EEG may be useful to identifying the discriminative spatial areas and time stages to improve the accuracies and efficiencies of object discrimination. In addition, investigating and utilizing humans'cognitive mechanisms of object recognition may improve computers' processing efficiency of visual information.

关键词： EEG spatio-temporal pattern object recognition single-trial analysis visual information processing

Level Set interface treatment and its application in Euler method

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Science China(Physics,Mechanics & Astronomy) 2010年第2期53卷 227-236页

作者： WU KaiTeng1,2,HAO Li3.WANG Cheng4 & ZHANG Li1,2 1 Numerical Simulation Sichuan Higher School key Laboratory,Neijiang normal university,Neijiang 641112,China 2 College of Mathematics and Information Science,Neijiang normal university,Neijiang 641112,China 3.College of Science,beijing university of Civil Engineering and Architecture,beijing 100044,China 4 State key Laboratory of Explosion Science and Technology,beijing Institute of Technology,beijing 100081,China Neijiang normal university Numerical Simulation Sichuan Higher School Key Laboratory Neijiang China (GRID:grid.464376.4) (ISNI:***) Neijiang normal university College of Mathematics and Information Science Neijiang China (GRID:grid.464376.4) (ISNI:***) beijing university of Civil Engineering and Architecture College of Science Beijing China (GRID:grid.411629.9) (ISNI:***) beijing Institute of Technology State Key Laboratory of Explosion Science and Technology Beijing China (GRID:grid.43555.32) (ISNI:***)

Level Set interface treatment method is introduced into Euler method,which is employed for interface treatment method for multi-materials. Combined with the ghost fluid method,the moving interface is tracked. Fifth-order WENO spatial discretization and third-order TVD Runge-Kutta time discretization methods are used. Shock-wave action on bubble,implosion and velocity field Shock effect bubbles; implosion and velocity field are simulated by means of LS-MMIC3. programmed by C++. Nu-merical results show that the Level Set interface treatment method is effective and feasible for multi-material interface treatment in comparison with the WENO method.

关键词： Euler method Level Set method shock-wave action on bubble implosion numerical simulation

Synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data

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Science China(Technological Sciences) 2008年第S2期51卷 176-187页

作者： BAO YunFei1,2,CAO ChunXiang1,ZHANG Hao1,CHEN ErXue3.HE QiSheng1,2,HUANG HuaBing1,LI ZengYuan3.LI XiaoWen1,4 & GONG Peng1 1 State key Laboratory of Remote Sensing Science,jointly sponsored by the Institute for Remote Sensing Applications of Chinese Academy of Sciences and beijing normal {3.,beijing 100101,China 2 Graduate {3. of the Chinese Academy of Sciences,beijing 100049,China 3.Institute of Forest Resource Information Technique,the Chinese Academy of Forestry,beijing 100091,China 4 Research Center for Remote Sensing and GIS,Department of geography and beijing key Laboratory for Remote Sensing of Environment and Digital Sites,beijing normal {3.,beijing 100875,China State key Laboratory of Remote Sensing Science jointly sponsored by the Institute for Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing China Graduate university of the Chinese Academy of Sciences Beijing China Institute of Forest Resource Information Technique the Chinese Academy of Forestry Beijing China Research Center for Remote Sensing and GIS Department of Geography and Beijing Key Laboratory for Remote Sensing of Environment and Digital Sites Beijing Normal University Beijing China

We proposed a method to separate ground points and vegetation points from discrete return,small footprint airborne laser scanner data,called skewness change *** method,which makes use of intensity of laser scanner data,is especially applicable in steep,and forested *** does not take slope of forested area into account,while other algorithms consider the change of slope in steep forested *** ground points and vegetation points can be used to estimate digital terrain model(DTM) and fractional vegetation cover,respectively.A few vegetation points which were classified into the ground points were removed as noise before the generation of *** method was tested in a test area of 10000 square meters.A LiteMapper -5600 laser system was used and a flight was carried out over a ground of 700―800 *** this tested area,a total number of 1546 field measurement ground points were measured with a total station TOPCON GTS-602 and TOPCON GTS -7002 for validation of DTM and the mean error value is -18.5 cm and the RMSE(root mean square error) is ±20.9 cm.A data trap sizes of 4m in diameter from airborne laser scanner data was selected to compute vegetation fraction *** of fractional vegetation cover was carried out using 15 hemispherical photographs,which are georeferenced to centimeter accuracy by differential *** gap fraction was computed over a range of zenith angles 10° using the gap light analyzer(GLA) from each hemispherical *** R2 for the regression of fractional vegetation cover from these ALS data and the respective field measurements is *** this study presents a method for synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data.

关键词： LIDAR intensity skewness synchronous DTM fractional vegetation cover

Redevelopment of liftoff rates of saltating sand grains based on a simple optimization model

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Science China Earth Sciences 2010年第4期53卷 568-574页

作者： CHENG Hong & ZOU XueYong State key Laboratory of Earth Surface Processes and Resource Ecology,beijing normal {3.,beijing 100875,China MOE Engineering Center of Desertification and Blown-sand Control,beijing normal {3.,beijing 100875,China key Laboratory of Environmental Change and Natural Disaster of the Ministry of Education of China,beijing normal {3.,beijing 100875,China State key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Beijing China MOE Engineering Center of Desertification and Blown-sand Control Beijing Normal University Beijing China key Laboratory of Environmental Change and Natural Disaster of the Ministry of Education of China Beijing Normal University Beijing China

This paper is a redevelopment result of liftoff rates of saltating sand grains based on our previous *** sand flow is a complex multi-phase flow because of a special two-phase gas-solid flow near ground *** extensive research on the movement of blowing sand,no model fully characterizes aeolian sand flow,and large differences often exist between simulations of aeolian sand movement and field *** key problem is a few of sufficient research on liftoff rates of saltating sand grains(also called the number of liftoff sand grains per unit time and per unit bed area).It is necessary to re-search in advance liftoff rates of saltating sand *** redeveloped liftoff rates of saltating sand grains by establishing an optimization model based on the flux of aeolian sand flow at different heights of the sampler in wind tunnel and the simulated capture of saltating sand grains by different heights of the sampler that are from different liftoff position(distance from the sampler) in order to revise previous inversion condition of liftoff rates of saltating sand *** rates increased rapidly with increasing wind *** frictional wind velocities of u=0.67,0.77,0.82,0.83.and 0.87 m s-1,liftoff rates were 3.40,954502,523.114,5499407,and 7696291 sand grain s-1 m-2,*** rates could be expressed as the square of the instantaneous frictional wind velocity and a constant(0.663. that differs from the critical(threshold) frictional wind velocity at which saltation *** our results require additional experimental validation and the simple optimization model must be improved,they nonetheless provide a strong basis for future research.

关键词： liftoff rates of saltating sand grains optimization model wind tunnel two-phase gas-solid flow

Exotic structure of the third excited state in^(21)Na

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Chinese Science Bulletin 2005年第23期50卷 2677-2680页

作者： LI Xihan1,2,3. LIANG Yujie1,2,3. DENG Fuguo1,2,3. LIU Zuhua1,4 & ZHOU Hongyu1,2,3.1. key Laboratory of Beam Technology and Material Modification of Minister of Education, beijing normal {3., beijing 100875, China 2. Institute of Low Energy Nuclear Physics, and Department of Material Science and Engineering, beijing normal {3., beijing 100875, China 3. beijing Radiation Center, beijing 100875, China 4. China Institute of Atomic Energy, beijing 102413. China key Laboratory of Beam Technology and Material Modification of Minister of Education Beijing Normal University Beijing 100875 China Institute of Low Energy Nuclear Physics and Department of Material Science and Engineering Beijing Normal University Beijing 100875 China beijing Radiation Center Beijing 100875 China China Institute of Atomic Energy Beijing 102413 China

The probability of the last proton being out of the binding potential, P and the root-mean-square (rms) ra- dius (1/2= of the third excited state in 21Na are calcu- lated by means of asymptotic normalization coefficie... 详细信息

The probability of the last proton being out of the binding potential, P and the root-mean-square (rms) ra- dius (2>1/2= of the third excited state in 21Na are calcu- lated by means of asymptotic normalization coefficient (ANC) method with the experimental date existing. The results are P=54.73. and 2>1/2=5.28 fm respectively. The P value and the contribution of the asymptotic part to the 2>1/2 are compared with those of several other low energy states in 21Na. It is found that the valence particle in the third excited state has an obvious larger P than those of other states. The density distribution of the valence proton in this state is also compared with the nucleons in the nuclear core 20Ne, and a far extended tail can be seen clearly. These results show that the third ex- cited state in 21Na is a proton halo state.

关键词：钠第三激发态外部结构有效半径密度分布渐近标准化系数