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Eco-Environmental Vulnerability Evaluation in the Yellow River Basin,China

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Pedosphere 2008年第2期18卷 171-182页

作者： WANG Si-Yuan LIU jing-Shi yang Cun-Jian Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 （China） Institute of Electronics Chinese Academy of Sciences Beijing 100080 （China） Centre of RS and GIS Applications Sichuan Normal University Chengdu 610066 （China）

Using remote sensing(RS)data and geographical information system(GIS),eco-environmental vulnerability and its changes were analyzed for the Yellow River Basin,*** objective of this study was to improve our understanding of eco-environmental changes so that a strategy of sustainable land use could be *** environmental numerical model was developed using spatial principal component analysis(SPCA)*** model contains twelve factors that include variables of land use,soil erosion,topography,climate,and *** this model,synthetic eco- environmental vulnerability index(SEVI)was computed for 1990 and 2000 for the Yellow River *** SEVI was classified into six levels,potential,slight,light,medium,heavy,and very heavy,following the natural breaks classification. The eco-environmental vulnerability distribution and its changes over the ten years from 1990 to 2000 were analyzed and the driving factors of eco-environmental changes were *** results show that the eco-environmental vulnerability in the study area was at medium level,and the eco-environmental quality had been gradually improved on the ***,the eco-environmental quality had become worse over the ten years in some *** the study area,population growth,vegetation degradation,and governmental policies for eco-environmental protection were found to be the major factors that caused the eco-environmental changes over the ten years.

关键词： eco-environmental vulnerability geographic information system (GIS) remote sensing (RS) spatial principal component analysis Yellow River Basin

Phylogenetic diversity of TypeⅠpolyketide synthase genes from sediments of Ardley Island in Antarctica

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Acta Oceanologica Sinica 2011年第6期30卷 104-111页

作者： ZHAO jing yang Ning CHEN Xinglin JIANG Qingru ZENG Runying Department of Marine Technology and Ocean Engineering College of Oceanography and Environmental Science Xiamen University Xiamen 361005 China Key Laboratory of Marine Biogenetic Resources Third Institute of Oceanography State Oceanic Administration Xiamen 361005 China

The diversity of modular polyketide synthase （PKS） genes in sediments of Ardley Island in Antarctica, was studied by restriction fragment length polymorphism （RFLP） analysis. Phylogenetic analysis of 14 amino acid （AA） sequences indicates that the identified ketosynthase （KS） domains were clustered with those from diverse bacterial groups, including Cyanobacteria, γ-Proteobacteria, Actinobacteria, Firmicutes, and some unidentified microorganisms from marine sponge, bryozoan and other environmental samples. The obtained KS domains showed 43%–81% similarity at the AA level to reference sequences in GenBank. Six identified KS domains showed diverse sequences of the motif （VQTACSTS） that was used to identify the hybrid PKS/nonribosomal peptide synthetase （NRPS） enzyme complex, and formed a new branch. These results reveal a high diversity and novelty of PKS genes in antarctic sediments.

关键词： polyketide synthase diversity Antarctica

A stable staggered-grid finite-difference scheme for acoustic modeling beyond conventional stability limit

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Petroleum Science 2024年第1期21卷 182-194页

作者： jing-Yi Xu yang Liu National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing 102249China China University of Petroleum(Beijing) Karamay CampusKaramay 834000XinjiangChina

Staggered-grid finite-difference(SGFD)schemes have been widely used in acoustic wave modeling for geophysical *** improved methods are proposed to enhance the accuracy of numerical ***,these methods are inevitably limited by the maximum Courant-Friedrichs-Lewy(CFL)numbers,making them unstable when modeling with large time sampling intervals or small grid *** solve this problem,we extend a stable SGFD scheme by controlling SGFD dispersion relations and maximizing the maximum CFL ***,to improve modeling stability,we minimize the error between the FD dispersion relation and the exact relation in the given wave-number region,and make the FD dispersion approach a given function outside the given wave-number area,thus breaking the conventional limits of the maximum CFL ***,to obtain high modeling accuracy,we use the SGFD scheme based on the Remez algorithm to compute the FD *** addition,the hybrid absorbing boundary condition is adopted to suppress boundary reflections and we find a suitable weighting coefficient for the proposed *** derivation and numerical modeling demonstrate that the proposed scheme can maintain high accuracy in the modeling process and the value of the maximum CFL number of the proposed scheme can exceed that of the conventional SGFD scheme when adopting a small maximum effective wavenumber,indicating that the proposed scheme improves stability during the modeling.

关键词： Acoustic wave Staggered-grid finite-difference(SGFD) modeling Courant-friedrichs-lewy(CFL)number Stability

A Type II Diabetic Model-from Insulin Resistance to Diabetes

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生物医学工程学杂志 2005年第S1期22卷 43-44页

作者： Yong WU~(1,2) jing-Ping OU yang~1 jing-Fang ZHANG~1 Ke WU~11(Department of Pathophysiology, Medical College of Wuhan University, Wuhan 430071, China)2(Department of Physiology, Hubei College of Traditional Chinese Medicine, Wuhan 430061, China)

Fixed-Time Sliding Mode Control With Varying Exponent Coefficient for Modular Reconfigurable Flight Arrays

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 514-528页

作者： Jianquan yang Chunxi yang Xiufeng Zhang jing Na Faculty of Mechanical and Electrical Engineering Kunming University of Science and TechnologyKunming 650500 Yunnan International Joint Laboratory of Intelligent Control and Aoolication of Advanced Equipment Kunming 650500China IEEE

The modular system can change its physical structure by self-assembly and self-disassembly between modules to dynamically adapt to task and environmental requirements. Recognizing the adaptive capability of modular systems, we introduce a modular reconfigurable flight array(MRFA) to pursue a multifunction aircraft fitting for diverse tasks and requirements,and investigate the attitude control and the control allocation problem by using the modular reconfigurable flight array as a platform. First, considering the variable and irregular topological configuration of the modular array, a center-of-mass-independent flight array dynamics model is proposed to allow control allocation under over-actuated situations. Secondly, in order to meet the stable, fast and accurate attitude tracking performance of the MRFA, a fixed-time convergent sliding mode controller with state-dependent variable exponent coefficients is proposed to ensure fast convergence rate both away from and near the system equilibrium point without encountering the singularity. It is shown that the controller also has fixed-time convergent characteristics even in the presence of external disturbances. Finally,simulation results are provided to demonstrate the effectiveness of the proposed modeling and control strategies.

关键词： Control allocation dynamic model fixed-time stabilization modular reconfigurable flight array(MRFA) sliding mode

Dissection of genetic overlap of salt tolerance QTLs at the seedling and tillering stages using backcross introgression lines in rice

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Science China(Life Sciences) 2008年第7期51卷 583-591页

作者： ZANG JinPing 1 ,SUN Yong 1 ,WANG Yun 1 ,yang jing 1 ,LI Fang 1 ,ZHOU YongLi 1 ,ZHU LingHua 1 , Reys JESSICA2,Fotokian MOHAMMADHOSEIN 2,XU JianLong 1&LI ZhiKang 1,2 1Institute of Crop Sciences/National Key Facility for Crop Gene Resources&Genetic Improvement,Chinese Academy of Agricul- tural Sciences,Beijing 100081,China 2International Rice Research Institute,DAPO Box 7777,Metro Manila,Philippines 1. Institute of Crop Sciences/National Key Facility for Crop Gene Resources & Genetic Improvement Chinese Academy of Agricultural Sciences Beijing 100081 China 2. International Rice Research Institute DAPO Box 7777 Metro Manila Philippines

QTLs for salt-tolerance(ST)related traits at the seedling and tillering stages were identified using 99 BC2F8 introgression lines(IL)derived from a cross between IR64(indica)as a recurrent parent and Binam(japonica)from Iran as the donor *** QTLs affecting survival days of seedlings(SDS), score of salt toxicity of leaves(SST),shoot K + concentration(SKC)and shoot Na + concentration(SNC) at the seedling stage and 22 QTLs underlying fresh weight of shoots(FW),tiller number per plant(TN) and plant height(PH)at the tillering stage were *** QTLs detected at the tillering stage showed obvious differential expression to salt stress and were classified into three types based on their differential *** I included 11 QTLs which were expressed only under the non-stress *** II included five QTLs expressed in the control and the salt stress conditions,and three of them(QPh5,QPh8 and QTn9)had similar quantity and the same direction of gene effect,suggesting their expression was less influenced by salt *** III included six QTLs which were detectable only under salt stress,suggesting that these QTLs were apparently induced by the *** QTLs affecting trait difference or trait stability of ILs between the stress and non-stress conditions were identified and the Binam alleles at all loci except QPh4,QTn2 and QFw2a decreased trait *** three QTLs less influenced by the stress and 13 QTLs affecting trait stability were considered as ST QTLs which contributed to *** the distribution of QTLs detected at the seedling and tillering stages,most(69%)of them were genetically *** four were the same or adjacent regions on chromosomes 1,2,8 and 11 harboring ST QTLs detected at the two stages,suggesting that partial genetic overlap of ST across the two stages *** is likely,therefore,to develop ST rice variety for both stages by pyramiding of ST QTLs of different stages or selection against the ove

关键词： rice salt tolerance(ST) quantitative trait loci(QTL) genetic overlap

Autonomous navigation method of satellite constellation based on adaptive forgetting factors

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Chinese Journal of Aeronautics 2024年第7期37卷 317-332页

作者： Dong WANG jing yang Kai XIONG School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control EngineeringBeijing 100094China

To address the problem that model uncertainty and unknown time-varying system noise hinder the filtering accuracy of the autonomous navigation system of satellite constellation,an autonomous navigation method of satellite constellation based on the Unscented Kalman Filter with Adaptive Forgetting Factors(UKF-AFF)is *** process noise covariance matrix is estimated online with the strategy that combines covariance matching and adaptive adjustment of forgetting *** adaptive adjustment coefficient based on squared Mahalanobis distance of state residual is employed to achieve online regulation of forgetting factors,equipping this method with more *** intersatellite direction vector obtained from photographic observations is introduced to determine the constellation satellite orbit together with the distance measurement to avoid rank deficiency *** that the number of available measurements varies online with intersatellite visibility in practical applications such as time-varying constellation configurations,the smooth covariance matrix of state correction determined by innovation and gain is adopted and constructed *** analysis of the proposed method is also *** effectiveness of the proposed method is verified by the Monte Carlo simulation and comparison *** estimation accuracy of constellation position and velocity of UKF-AFF is improved by 30%and 44%respectively compared to those of the extended Kalman filter,and the method proposed is also better than other several adaptive filtering methods in the presence of significant model uncertainty.

关键词： Constellation autonomous navigation Unscented Kalman filter Adaptive forgetting factor Model uncertainty Stability analysis

Parametric“non-nested”discriminants for multiplicities of univariate polynomials

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Science China Mathematics 2024年第8期67卷 1911-1932页

作者： Hoon Hong jing yang Department of Mathematics North Carolina State UniversityRaleighNC 27695USA SMS-HCIC-School of Mathematics and Physics Center for Applied Mathematics of GuangxiGuangxi Minzu UniversityNanning 530006China

We consider the problem of complex root classification,i.e.,finding the conditions on the coefficients of a univariate polynomial for all possible multiplicity structures on its complex *** is well known that such conditions can be written as conjunctions of several polynomial equalities and one inequality in the *** polynomials in the coefficients are called discriminants for *** is also known that discriminants can be obtained using repeated parametric greatest common *** resulting discriminants are usually nested determinants,i.e.,determinants of matrices whose entries are determinants,and so *** this paper,we give a new type of discriminant that is not based on repeated greatest common *** new discriminants are simpler in the sense that they are non-nested determinants and have smaller maximum degrees.

关键词： parametric polynomial complex roots discriminant multiplicity resultant

Center of the yangian double in type A

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Science China Mathematics 2024年第9期67卷 1957-1988页

作者： Fan yang Naihuan jing Department of Mathematics Jiaying UniversityMeizhou 514000China Department of Mathematics North Carolina State UniversityRaleighNC 27695USA

We prove that the R-matrix and Drinfeld presentations of the yangian double in type A are *** central elements of the completed yangian double in type A at the critical level are *** images of these elements under a Harish-Chandra-type homomorphism are calculated by applying a version of the Poincaré-Birkhoff-Witt theorem for the R-matrix *** images coincide with the eigenvalues of the central elements in the Wakimoto modules.

关键词： yangian double Harish-Chandra homomorphism Wakimoto module