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Progress in Natural science:Materials International 2006年第4期16卷 366-372页

作者： XIE Baoen and CHEN Sanfeng State Key Laboratory for Agrobiotechnology, college of Biological sciences, china agricultural university, beijing 100094, china State Key Laboratory for Agrobiotechnology College of Biological Sciences China Agricultural University Beijing 100094 China

To bring more information about synthesis of indole-3-acetic acid (IAA) from Azospirillum brasilense, a Tn5-insertion library of A. brasilense Yu62 was constructed and subjected to screening for IAA producing mutants. Two mutants with decreased IAA levels, named as A3 and A24, were isolated. The sequence analysis of loci tagged showed that the Tn5-1063a was located in the atrA gene encoding GntR family transcriptional regulator and trpE gene encoding component I of anthranilate synthase respectively. At the same time. atrB encoding phosphotransferase and atrC encoding aminotransferase were cloned downstream the atrA gene and atrA, atrB and atrC were clustered in an operon. Mutagenesis and complementation studies showed that atrA and atrC were involved in IAA synthesis. IAA levels of trpE mutant and wild-type strain could be improved by adding anthranilate into the medium.

关键词： indole-3-acetic acid (IAA) IAA mutants Azospirillum brasilense atrABC cluster trpE Tn5 transposon.

Analysis on the positioning precision of CAPS

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science china(Physics,Mechanics & Astronomy) 2009年第3期52卷 328-332页

作者： JI YuanFa1,2 & SUN XiYan1,2 1 National Astronomical Observatories, Chinese Academy of sciences, beijing 100012, china 2 Applied science and technology college, Guilin university of Electronic technology, Guilin 541004, china National Astronomical Observatories Chinese Academy of Sciences Beijing China Applied science and technology college Guilin University of Electronic Technology Guilin China

As a newly developed satellite positioning system, the Chinese Area Positioning System (CAPS) is a typical direct sequence spread spectrum ranging system like GPS. The positioning precision of such navigation signals depends on many factors, including the pseudo-code rate, the signal to noise ratio, the processing methods for tracking loops and so on. This paper describes the CAPS link budget, the solution approach for CAPS positioning, focusing on the autocorrelation function feature of C/A code signals. The CAPS signal measurement precision is studied by the software approach together with theoretical analysis of the range resolution. Because the conventional Delay Lock Loop (DLL) is vul- nerable to the impact of noise, a narrow correlator and multiple correlators as well as the corresponding discrimination methods of phases are proposed, which improves the robustness of DLL and the code-phase resolution of the measurement. The results show that the improvement of the DLL structure and the discrimination method are the most important way to improve the ranging resolution. Theoretical analysis and experimental results show that a CAPS receiver could reach a 20-m positioning precision by using three satellites with a supported height from an altimeter.

关键词： satellite navigation receiver narrow correlation tracking loop

Construction and characterization of the transformation-competent artificial chromosome (TAC) libraries of Leymus multicaulis

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science china(Life sciences) 2008年第7期51卷 604-613页

作者： XU YueYu 1,2,3,ZHOU YuLei 4,5 ,SONG LinLin 6 ,ZHANG Yan 3 &ZHAO MaoLin 1 1 beijing Agro-Biotechnology Research Center,beijing Academy of Agriculture and Forestry science,beijing 100097,china 2 Department of Chemistry and Chemical Engineering,Hunan Institute of Engineering,Xiangtan 411104,china 3 college of Life science,Capital Normal university,beijing 100037,china 4 college of Life science,Zhongkai university of Agriculture and technology,Guangzhou 510225,china 5 college of Grassland science,Gansu agricultural university,Lanzhou 730070,china 6 Department of Biology,Henan Institute of science and technology,Xinxiang 453003,china beijing Agro-Biotechnology Research Center Beijing Academy of Agriculture and Forestry Science Beijing China Department of Chemistry and Chemical Engineering Hunan Institute of Engineering Xiangtan China college of Life science Capital Normal University Beijing China college of Life science Zhongkai University of Agriculture and Technology Guangzhou China college of Grassland science Gansu Agricultural University Lanzhou China Department of Biology Henan Institute of Science and Technology Xinxiang China

Transformation-competent artificial chromosome system is able to clone and transfer genes efficiently in *** order to clone genes highly tolerant to barley yellow dwarf virus(BYDV),Aphids,drought and salt from Leymus multicaulis,the two TAC genomic libraries I and II were constructed in vector pYLTAC17 and pYLTAC747H/sacB,which contain about 165000 and 236000 recombinant clones *** genome coverage of the two libraries was totally estimated to be about 3―5 haploid genome equivalents,as size selection of genomic DNA fragments was approximately from 9 to 300 *** of the genomic libraries were collected as bulked pools each containing 500 clones or so,stored in twelve 96-deep-well plates and then were gridding in triplicate onto a high-density colony hybridization filter with a 3×3 pattern using a GeneTAC?G3 arraying robot after being transferred manually into three 384-well *** 2501 and 2890 clones of Library in pYLTAC17 and in pYLTAC747H/sacB were stored individually in fourteen 384-well plates and then were automatically gridding in duplicate onto a high-density colony hybridization filter with a 6×6 pattern after a replication of *** positive clones were detected by using the probe glutahione reductase gene of *** libraries constructed here can be used to isolate genomic clones containing target genes,and to carry out genome walking for positional *** the target TAC clones were isolated,they could be immediately transferred into plant genomes with the Agrobacterium system.

关键词： Leymus multicaulis megabase-size DNA transformation-competent artificial chromosome(TAC) genomic library

Computational theory of cavitating flows for hydraulic turbomachinery with consideration of influence of water quality

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science china(Technological sciences) 2010年第12期53卷 3341-3348页

作者： WANG Lei1,2 & CHANG JinShi2 1 Huadian Electric Power Research Institute, Hangzhou 310030, china 2 college of Water Conservancy and Civil Engineering, china agricultural university, beijing 100083, china Huadian Electric Power Research Institute Hangzhou China college of Water Conservancy and Civil Engineering China Agricultural University Beijing China

Previously it was assumed that the pressure within the cavity or on the cavity surface remained constant and the vapor pressure of clean water at 20°C and 0 m altitude was utilized as the computational boundary for cavitating flows in hydraulic turbomachinery. Cavitation was confused with vaporization, and the effect of water quality on cavitation pressure characteristics was not taken into account. In recent years, lots of experiments of cavitation pressure characteristics of different water qualities including different sand concentrations of sand water and different altitudes of clean water have been performed by the authors, and the important influences of water quality on cavitation pressure characteristic have been validated. Thus the water quality should be involved in the cavitating flows computation. In the present paper, the effect of water quality on the cavitation pressure characteristic is analyzed and the computational method and theory of cavitating flows for hydraulic turbomachinery that considers the influence of water quality are proposed. The theory is suitable for both the potential flow method and the two-phase flow method for cavitating flows simulation. Finally, the validation results for cavitating flows in a hydraulic tur- bine indicate the significant influences of water quality on the cavitating flow performance.

关键词： cavitating flows cavitation pressure water quality hydraulic turbomachinery

A heuristic path-estimating algorithm for large-scale real-time traffic information calculating

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science china(Technological sciences) 2008年第S1期51卷 165-174页

作者： L WeiFeng1,ZHU TongYu1,WU DongDong2,DAI Hong3 & HUANG Jian1 1 State Key Laboratory for Software Development Environment,Beihang university,beijing 100083,china 2 beijing Transportation Information Center,beijing 100055,china 3 college of Arts & science,beijing Union university,beijing 100083,china State Key Laboratory for Software Development Environment Beihang University Beijing China beijing Transportation Information Center Beijing China college of Arts & science Beijing Union University Beijing China

As the original Global Position System (GPS) data in Floating Car Data have the accuracy problem,this paper proposes a heuristic path-estimating algorithm for large-scale real-time traffic information calculating. It uses the heuristic search method,imports the restriction with geometric operation,and makes comparison between the vectors composed of the vehicular GPS points and the special road network model to search the set of vehicular traveling route candidates. Finally,it chooses the most optimal one according to weight. Experimental results indicate that the algorithm has considerable efficiency in accuracy (over 92.7%) and com-putational speed (max 8000 GPS records per second) when handling the GPS tracking data whose sampling rate is larger than 1 min even under complex road network conditions.

关键词： path-estimating floating car data (FCD) road network vector GPS

Theory and techniques of data mining in CGF behavior modeling

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science china(Information sciences) 2011年第4期54卷 717-731页

作者： YIN YunFei 1,2,GONG GuangHong 2 & HAN Liang 2 1 college of Computer science,Chongqing university,Chongqing 400044,china 2 School of Automation science and Electrical Engineering,beijing university of Aeronautics and Astronautics,beijing 100083,china college of Computer science Chongqing University Chongqing China School of Automation science and Electrical Engineering Beijing University of Aeronautics and Astronautics Beijing China

For the large quantity of data,rules and models generated in the course of computer generated forces (CGFs) behavior modeling,the common analytical methods are statistical methods based on the tactical rules,tactical doctrine and empirical ***,from the viewpoint of data mining,we can find many of these analytical methods are also each-and-every different data mining *** this paper,we survey the data mining theory and techniques that have appeared in the course of CGF behavior modeling from the viewpoint of data ***,we redefine and reclassify these theories and techniques according to the research requirements of data mining (the knowledge structure of data mining).We aim to help the CGF investigators to learn the key points and the research methods of the data intelligent processing in the CGF behavior modeling,and thus we can provide the references for the colleagues who are engaged in the research and practice of the CGF behavior modeling by this *** also introduce our ongoing work on the CGF behavior modeling based on data mining.

关键词： CGF CGF behavior modeling data mining theory and techniques

Arbitrarily long distance quantum communication using inspection and power insertion

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Chinese science Bulletin 2009年第1期54卷 158-162页

作者： WANG WanYing1,2,WANG Chuan1,2,ZHANG GuangYu1,3 & LONG GuiLu1,2 1 Department of Physics,Tsinghua university,beijing 100084,china 2 Tsinghua National Laboratory for Information science and technology,Tsinghua university,beijing 100084,china 3 college of Applied science,Harbin university of science and technology,Harbin 150080,china Department of Physics Tsinghua University Beijing China Tsinghua National Laboratory for Information science and technology Tsinghua University Beijing China college of Applied science Harbin University of Science and Technology Beijing China

The biggest obstacle for long distance quantum communication is the channel loss and the channel noise on photons. In this paper,a method to solve this problem was analyzed using inspection and power insertion (IPI). It is proved that quantum communication may be established over arbitrarily long distance using this technology. The amount of resources required is a polynomial function of the dis-tance. IPI is proposed as a general technique to prolong quantum secure direct communication where secret messages are transmitted directly over a quantum channel.

关键词：长距离量子通信量子安全通信量子密匙分布噪声

A new class of impulse stochastic control models with non-negative control quantity

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science china(Information sciences) 2011年第3期54卷 638-652页

作者： LIU XiaoPeng & LIU KunHui college of science, beijing Jiaotong university, beijing 100044, china college of science Beijing Jiaotong University Beijing China

This paper advances and studies a new class of impulse stochastic control models. Its state structure is defined by a linear stochastic differential equation of the semi-martingale, its control cost function is a twovariable function of pre-control state quantity and control quantity, and its control quantity is kept non-negative. First this paper constructs a new type of variational equations and proves its solution exists. Using a series of stochastic analysis methods to research the solution function of this type of variational equations, this paper proves the existence of optimal control and analyzes its structure in depth. Because of the big difference between the model in this paper and stochastic control models in previous papers, the analysis method here is quite different from previous ones. It is expected that this paper will have important theoretical significance for stochastic control research, along with wide applicative value in finance control and security management.

关键词： impulse stochastic control control quantity variational equation optimal control semi-martingale

RNA-binding Domain of the Key Structural Protein P7 for the Rice dwarf virus Particle Assembly

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Acta Biochimica et Biophysica Sinica 2005年第1期37卷 55-60页

作者： Bo-Xiong ZHONG~(1,2*) Yan-Wei SHEN~1 Toshihiro OMURA~2 ~1 Department of Bioresource science.college of animal science,Zhejiang university,Hangzhou 310029,china ~2National agricultural Research Center,Tsukuba.Ibaraki 305,Japan Department of Bioresource science College of Animal Science Zhejiang UniversityHangzhou 310029 China National agricultural Research CenterTsukuba Ibaraki 305 Japan

The Rice dwarf virus(RDV)P7 structural protein is the key protein in the RDV *** P7 protein was digested partially or completely by Staphylococcus aureus V8 protease and/orPseudomonas fragi Asp-N *** molecular mass and the N-terminal amino acid sequence of thepolypeptide fragments of the P7 protein were determined by SDS-PAGE and the Edman degradation method,*** the polypeptides were located in the deduced amino acid sequence of the RDV P7 proteinbased on the nucleotide sequence information,with the knowledge of the specific cleavage sites of theStaphylococcus aureus V8 and Pseudomonas fragi Asp-N protease,and the two RNA-binding domains in theP7 protein were *** 1 was located in the residue 128-249 containing 122 amino acids anddomain 2 was located in the residue 325-355 containing 31 amino ***,these two domains may playan important role in the virus particle assembly by contributing to the packaging of viral dsRNAs inside *** two domains may be novel RNA-binding domains,because no amino acid sequences highlysimilar to the conservative sequences of known dsRNA-binding domains reported so *** similaritybetween the motif of domain 1 and the motif of the DNA-binding protein suggests that the DNA-bindingactivity of the RDV P7 protein may be due to this *** similarity between the motif of domain 1 andthe motif of the RNA polymerase domain suggests that the P7 protein may also play a role in RNA synthesis,besides its function in the assembly and subsequent packaging of viral dsRNA into core particles.

关键词： RDV RNA-binding protein protein functional domain virion assembly RNA polymerase

Efficient production of omega-3 fatty acid desaturase (sFat-1)-transgenic pigs by somatic cell nuclear transfer

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science china(Life sciences) 2010年第4期53卷 517-523页

作者： PAN DengKe1, ZHANG Li1, ZHOU YanRong2, FENG Chong1, LONG Chuan1, LIU Xiao1, WAN Rong3, ZHANG Jian3, LIN AiXing3, DONG EnQiu4, WANG ShuChen4, XU HouGang4 & CHEN HongXing2 1 Institute of animal sciences, Chinese Academy of agricultural sciences, beijing 100193, china 2 beijing Institute of Biotechnology, beijing 100071, china 3 china agricultural university, beijing 100193, china 4 Yutian Breeding Swine Farms, Yutian 064104, china Institute of animal sciences Chinese Academy of Agricultural Sciences Beijing China beijing Institute of Biotechnology Beijing China china agricultural university Beijing China Yutian Breeding Swine Farms Yutian China

Omega-3(ω-3) fatty acid desaturase transgenic pigs may improve carcass fatty acid composition. The use of transgenic pigs is also an excellent large animal model for studying the role of ω-3 fatty acids in the prevention and treatment of coronary heart disease and cancer. Transgenic pigs carrying synthesized fatty acid desaturase-1 gene (sFat-1) from Caenorhabditis briggsae by somatic cell nuclear transfer (SCNT) were produced for the first time in china. Porcine fetal fibroblast cells were transfected with a sFat-1 expression cassette by the liposome-mediated method. Transgenic embryos were reconstructed by nuclear transfer of positive cells into enucleated in vitro matured oocytes. A total of 1889 reconstructed embryos were transferred into 10 naturally cycling gilts. Nine early pregnancies were established, 7 of which went to term. Twenty-one piglets were born. The cloning efficiency was 1.1% (born piglets/transferred embryos). The integration of the sFat-1 gene was confirmed in 15 live cloned piglets by PCR and Southern blot except for 2 piglets. Expression of the sFat-1 gene in 12 of 13 piglets was detected with RT-PCR. The data demonstrates that an efficient system for sFat-1 transgenic cloned pigs was developed, which led to the successful production of piglets expressing the sFat-1 gene.

关键词： sFat-1 nuclear transfer ovulation status transgenic pig