检索结果-南通市图书馆

Science China Earth Sciences 2008年第1期51卷 114-122页

作者： Fu Rong hu Liang Gu GuoJun Li YaoDong Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China School of Earth and Atmospheric Sciences Georgia Institute of Technology Atlanta GA 30332 USA Goddard Earth Sciences and Technology Center University of

Summer-time synoptic-scale waves in South China and the Yangtze River basin are quantified and compared by means of analyzing the 6-year (1998–2004) TRMM Multi-Satellite Precipitation Analysis (TMPA) daily product. A... 详细信息

关键词： TRMM 3-dimensional spectrum analysis synoptic-scale waves South China Yangtze River basin

Residual-based a posteriori error estimates for symmetric conforming mixed finite elements for linear elasticity problems

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2018年第6期61卷 973-992页

作者： Long Chen Jun hu Xuehai huang Hongying Man Department of Mathematics University of California at Irvine LMAM and School of Mathematical Sciences Peking University College of Mathematics and Information Science Wenzhou University School of Mathematics and Statistics Beijing Institute of Technology

A posteriori error estimators for the symmetric mixed finite element methods for linear elasticity problems with Dirichlet and mixed boundary conditions are proposed. Reliability and efficiency of the estimators are p... 详细信息

关键词： symmetric mixed finite element linear elasticity problems a posteriori error estimator adaptivemethod

A two‐branch network with pyramid‐based local and spatial attention global feature learning for vehicle re‐identification

在线全文

学校读者我要写书评

暂无评论

CAAI Transactions on Intelligence Technology 2021年第1期6卷 46-54页

作者： Jucheng Yang Di Xing Zhiqiang hu Tong Yao College of Artificial Intelligence Tianjin University of Science and TechnologyTianjinPeople’s Republic of China

In recent years,vehicle re‐identification has attracted more and more *** to learn the discriminative information from multi‐view vehicle images becomes one of the challenging problems in vehicle re‐identification *** example,when the viewpoint of the image changes,the features extracted from one image may be lost in another image.A two‐branch network with pyramid‐based local and spatial attention global feature learning(PSA)is proposed for vehicle re‐identification to solve this ***,one branch learns local features at different scales by building pyramid from coarse to fine and the other branch learns attentive global features by using spatial attention ***,pooling operation by using global maximum pooling(GMP)for local features and global average pooling(GAP)for global feature is ***,local feature vectors and global feature vector extracted from the last pooling layer,respectively,are employed for identity re‐*** experimental results demonstrate that the proposed method achieves state‐of‐the‐art results on the VeRi‐776 dataset and VehicleID dataset.

关键词： branch pyramid learning

Variable selection in near infrared spectroscopy for quantitative models of homologous analogs of cephalosporins

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2014年第4期7卷 91-100页

作者： Yan-Chun Feng Zhen Ni Chang-Qin hu National Institutes for Food and Drug Control(NIFDC)Beijing 100050 P.R.China Tibet Institute for the Control of Food and Pharmaceutical Products Lhasa 850000 P.R.China

Two universal spectral ranges(4550-4100 cm^(-1) and 6190-5510 cm^(-1))for construction of quantitative models of homologous analogs of cephalosporins were proposed by evaluating theperformance of five spectral ranges and their combinations,using three data sets of cephalos-porins for injection,ie.,cefuroxime sodium,cetriaxone sodium and cefoperazone ***,the proposed ranges were validated by using eight calibration sets of otherhomologous analogs of cephalosporins for injection,namely cefmenoxime hydrochloride,ceftezole sodium,cefmetazole,cefoxitin sodium,cefotaxime sodium,cefradine,cephazolin sodium and ceftizoxime *** the constructed quantitative models for the eight kinds of cephalosporinsusing these universal ranges could fulill the requirements for quick *** that,competitive adaptive reweighted sampling(CARS)algorithm and infrared(IR)-near infrared(NIR)two-dimensional(2D)correlation spectral analysis were used to determine the scientific basis of these two spectral ranges as the universal regions for the construction of quantitativemodels of *** CAR.S algorithm demonstrated that the ranges of 4550-4100 cm^(-1) and 6190-5510 cm^(-1) included some key wavenumbers which could be attributed to content changes of *** IR-NIR 2D spectral analysis showed that certain wavenumbersin these two regions have strong correlations to the structures of those cephalosporins that wereeasy to degrade.

关键词： Near infrared spectroscopy cephalosporins quantitation spectral range selection

Irreducible function bases of isotropic invariants of a third order three-dimensional symmetric and traceless tensor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2019年第1期14卷 1-16页

作者： Yannan CHEN Shenglong hu Liqun QI Wennan ZOU School of Mathematical Sciences South China Normal University Guangzhou 510631 China Department of Mathematics School of Science Hangzhou Dianzi University Hangzhou 310018 China Department of Applied Mathematics The Hong Kong Polytechnic University Hong Kong China Institute for Advanced Study Nanchang University Nanchang 330031 China

Third order three-dimensional symmetric and traceless tensors play an important role in physics and tensor representation theory. A minimal integrity basis of a third order three-dimensional symmetric and traceless tensor has four invariants with degrees two, four, six, and ten, respectively. In this paper, we show that any minimal integrity basis of a third order three-dimensional symmetric and traceless tensor is also an irreducible function basis of that tensor, and there is no syzygy relation among the four invariants of that basis, i.e., these four invariants are algebraically independent.

关键词： Minimal integrity basis irreducible function basis symmetric and traceless tensor syzygy

Model updating based on incomplete modal data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第7期54卷 1737-1747页

作者： LI huaJun WANG JunRong hu Sau-Lon James Shandong Provincial Key Lab of Ocean Engineering Ocean University of China Qingdao 266100 China CNOOC Research Institute China National Offshore Oil Corporation Beijing 100027 China Department of Ocean Engineering University of Rhode Island Narragansett RI 02882-1197 USA

The objective of model updating is to improve the accuracy of a dynamic model based on the correlation between the measured data and the analytical (finite element) model. In this paper, we intend to update the mass and stiffness matrices of an analytical model when only modal frequencies or spatially incomplete modal data are available. While the proposed method is systematic in nature, it also preserves the initial configuration of the analytical model, and physical equality and/or inequality constraints can be easily incorporated into the solution procedure. Numerical examples associated with a simple 5-DoF (degree of freedom) mass-spring system are chosen to illustrate the detailed procedure and the effectiveness of the proposed method. Numerical scenarios ranging from the updating for stiffness terms only to that for all mass and stiffness terms based on various kinds of incomplete modal data are studied. The obtained model updating results are excellent when the measured modal data are noise-free. Uncertainty studies are also conducted based on simulations of corrupted modal data, but a thorough theoretical analysis of the noise effect on the proposed method is still needed.

关键词： model updating model reduction modal expansion incomplete mode

On the Solutions of the Matrix Equations in Optimal Stochastic Control

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 1999年第3期10卷 38-43页

作者： Deng, Feiqi hu, Gang Liu, Yongqing Feng, Zhaoshu South China Univ of Technology Guangzhou China

In this paper, the matrix algebraic equations involved in the optimal control problem of time-invariant linear Ito stochastic systems, named Riccati- Ito equations in the paper, are investigated. The necessary and sufficient condition for the existence of positive definite solutions of the Riccati- Ito equations is obtained and an iterative solution to the Riccati- Ito equations is also given in the paper thus a complete solution to the basic problem of optimal control of time-invariant linear Ito stochastic systems is then obtained. An example is given at the end of the paper to illustrate the application of the result of the paper.

关键词： Computational methods Control system analysis Control system synthesis Iterative methods Linear control systems Matrix algebra Optimal control systems Riccati equations

Envelope and Classification of Global Structures of Solutions for a Class of Two-dimensional Conservation Laws

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2016年第3期32卷 579-590页

作者： Gao-wei CAO Kai hu Xiao-zhou YANG Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences

Two-dimensional Riemann problem for scalar conservation law are investigated and classification of global structure for its nomselfsimilar solution is given by analysis of structure and classification of envelope for non-selfsimilar 2D rarefaction wave. Initial data has two different constant states which are separated by initial discontinuity. We propose the concepts of plus envelope, minus envelope and mixed envelope, and some new structures and evolution phenomena are discovered by use of these concepts.

关键词： shock wave rarefaction wave cylinder face envelope non-selfsimilar solution

A power fluctuation evaluation method of PV plants based on RankBoost ranking

在线全文

学校读者我要写书评

暂无评论

Protection and Control of Modern Power Systems 2021年第1期6卷 347-356页

作者： Weiyi Xia Zhouyang Ren hui Li Bo hu The State Key Laboratory of Power Transmission Equipment&System Security and New Technology School of Electrical EngineeringChongqing UniversityChongqing400044PR China

Fluctuation evaluation is an important task in promoting the accommodation of photovoltaic (PV) power generation. This paper proposes an evaluation method to quantify the power fluctuation of PV plants. This consists of an index system and a ranking method based on the RankBoost algorithm. Eleven indices are devised and included in the index system to fully cover diverse fluctuation features. By handling missing and invalid data effectively, the ranking method fuses multiple indices automatically and provides a systematic and comprehensive comparison of power fluctuation. Simulation results based on power data from six PV plants indicate that the evaluation list obtained by the RankBoost ranking method is better represented and more comprehensive than that derived by the equal weight method.

关键词： Fluctuation evaluation Photovoltaic power RankBoost ranking algorithm

Direct Electrochemistry of Horseradish Peroxidase Immobilized in a Low Molecular Weight Gel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2014年第3期32卷 263-268页

作者： Yan hu Yanwen Sun Lu Lu Xirong huang Key Laboratory of Colloid&Interface Chemistry of the Education Ministry of China Shandong UniversityJinanShandong 250100China

The ternary system of dodecylpyridinium bromide(DDPB)/acetone/H2O with appropriate composition can form a gel spontaneously and the gel is stable in hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophos-phate([Bmim]PF_(6)).Based on the gelation phenomenon we observed,the low molecular weight gelator(LMWG)was first tried to immobilize horseradish peroxidase(HRP)on glassy carbon electrode(GCE).The scanning elec-tron microscope(SEM)images,the UV-Vis spectra and the bioactivity measurement indicate that the gel is suitable for the immobilization of *** direct electrochemistry of the HRP-gel modified GCE(HRP-gel/GCE)in[Bmim]PF_(6)shows a pair of well-defined and quasi-reversible redox peaks with the heterogeneous electron transfer rate constant(ks)being 14.4 s^(−1),indicating that the direct electron transfer between HRP and GCE is *** HRP-gel/GCE is stable and *** the electrode exhibits good electrocatalytic effect on the reduction of trichloroacetic acid(TCA),showing good promise in bioelectrocatalysis.

关键词： low molecular weight gelator horseradish peroxidase electron transfer bioelectrocatalysis biosensors