检索结果-南通市图书馆

Chinese Quarterly Journal of Mathematics 2008年第3期23卷 360-367页

作者： CHEN Qing-jiang LIU Hong-yun School of Science Xi＇an University of Architecture and Technology Xi＇an 710055 China Institute of Higher vocational Education Shangqiu Vocational and Technical College Shangqiu 476000 China

The notion of vector-valued multiresolution analysis is introduced and the concept of orthogonal vector-valued wavelets with 3-scale is proposed. A necessary and sufficient condition on the existence of orthogonal vector-valued wavelets is given by means of paraunitary vector filter bank theory. An algorithm for constructing a class of compactly supported orthogonal vector-valued wavelets is presented. Their characteristics is discussed by virtue of operator theory, time-frequency method. Moreover, it is shown how to design various orthonormal bases of space L^2（R, C^n） from these wavelet packets.

关键词： orthogonal Hermitian matrix vector-valued multiresolution analysis vector-valued scaling functions vector-valued wavelets vector-valued wavelet packets

Effective components of Chinese herbs reduce central nervous system function decline induced by iron overload

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2015年第5期10卷 778-785页

作者： xian-hui Dong jiang-tao Bai Wei-na Kong xiao-ping He Peng Yan Tie-mei Shao Wen-guo Yu xi-qing Chai Yan-hua Wu Cong Liu Chengde Medical University Hebei Chemical and Pharmaceutical vocational and technical college The 266 Hospital of Chinese PLA

Abnormally increased levels of iron in the brain trigger cascade amplification in Alzheimer＇s dis- ease patients, resulting in neuronal death. This study investigated whether components extracted from the Chinese herbs epimedium herb, milkvetch root and kudzuvine root could relieve the abnormal expression of iron metabolism-related protein in Alzheimer＇s disease patients. An APPs,~JPSI^E9 double transgenic mouse model of Alzheimer＇s disease was used. The intragas- tric administration of compounds from epimedium herb, milkvetch root and kudzuvine root improved pathological alterations such as neuronal edema, increased the number of neurons, downregulated divalent metal transporter 1 expression, upregulated ferroportin 1 expression, and inhibited iron overload in the cerebral cortex of mice with Alzheimer＇s disease. These com- pounds reduced iron overload-induced impairment of the central nervous system, indicating a new strategy for developing novel drugs for the treatment of Alzheimer＇s disease.

关键词： nerve regeneration neurodegenerative diseases Alzheimer's disease transgenic animalmodels mice epimedium herb milkvetch root kudzuvine root divalent metal transporter 1 ferroportin 1 neural regeneration

Decondensation behavior of DNA chains induced by multivalent cations at high salt concentrations:Molecular dynamics simulations and experiments

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第11期24卷 610-618页

作者：蒋杨伟冉诗勇何林李王向红章林溪 Department of Physics Zhejiang University Department of Physics Wenzhou University Department of Electrical and Electronic Engineering Wenzhou Vocational and Technical College

Using molecular dynamics simulations and atomic force microscopy （AFM）, we study the decondensation process of DNA chains induced by multivalent cations at high salt concentrations in the presence of short cationic chains in solutions. The typical simulation conformations of DNA chains with varying salt concentrations for multivalent cations imply that the concentration of salt cations and the valence of multivalent cations have a strong influence on the process of DNA decondensation. The DNA chains are condensed in the absence of salt or at low salt concentrations, and the compacted conformations of DNA chains become loose when a number of cations and anions are added into the solution. It is explicitly demonstrated that cations can overcompensate the bare charge of the DNA chains and weaken the attraction interactions between the DNA chains and short cationic chains at high salt concentrations. The condensation-decondensation transi- tions of DNA are also experimentally observed in mixing spermidine with X-phage DNA at different concentrations of NaCl/MgCl2 solutions.

关键词： DNA decondensation salt concentration multivalent cations molecular dynamics simulation

Confirmed Diagnosis by RT-PCR and Phylogenetic Analysis of Peste des Petits Ruminants Viruses in Tibet, China

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2009年第6期24卷 573-578页

作者： Wen-hua ZHAO Shi-biao YANG Jian-qiang HAN Mei jiang Hua-chun LI Nian-zu ZHANG Qi-han LI Laboratory of Tropical and Subtropical Animal Virology of MOA National Exotic Animal Disease Diagnostic Laboratory Kunming 650224 China Yu xi Agriculture vocational technical college Yu Xi 653100 China Peking Union Medical college Tsinghua University Kunming Jiaoling Road 3 79# Kunming 65011 8 China

This paper reports the confirmed diagnosis by nested RT-PCR of PPR cases in Tibet, China in 2007, and results of phylogenetic analysis. Results showed that the 11 tested samples were PPRV positive by nested RT-PCR, of which 2 samples were genetically close to the X7443 strain (Nigeria 75/1) of lineage I, and 3 samples close to the strain AY560591 (Sungri96) of linage IV with 96.6%、97.3%、97.6% and 98% nucleotide sequence homogeneity respectively, based on partial sequencing of the F gene from 5 samples and complete sequencing of the N/M/F/H genes from one sample. This study suggested that there are at least 2 origins of PPRV in China.

关键词： Peste des petitis ruminants virus (PPRV) Tibet RT-PCR Open reading frame (ORF) Phylogenetic analysis

Capacitive micromachined ultrasonic transducer as a resonant temperature sensor

在线全文

学校读者我要写书评

暂无评论

Instrumentation 2014年第3期1卷 67-74页

作者： LI Zhikang Rahman hebibul ZHAO Libo YE Zhiying ZHAO Yulong jiang Zhuangde State Key Laboratory for Manufacturing Systems Engineering Collaborative Innovation Center of Suzhou Nano Science and TechnologyXi'an Jiaotong UniversityXi'an710049China Department of Mechanical Engineering University of California at BerkeleyBerkeleyCA 94720USA School of Automotive Mechanical and Electrical EngineeringXinjiang Vocational&Technical College of CommunicationsUrumqi831401China

Resonant temperature sensors have drawn considerable attention for their advantages such as high sensitivity,digitized signal output and high *** paper presents a new type of resonant temperature sensor,which uses capacitive micromachined ultrasonic transducer(CMUT)as the sensing element.A lumped electro-mechanical-thermal model was established to show its working principle for temperature *** theoretical model explicitly explains the thermally induced changes in the resonant frequency of the ***,the finite element method was used to further investigate the sensing *** numerical results agree well with the established analytical model *** numerical results show that the resonant frequency varies linearly with the temperature over the range of 20℃to 140℃ at the first four vibrating ***,the first order vibrating mode shows a higher sensitivity than the other three higher *** working at the first order vibrating mode,the temperature coefficient of the resonance frequency(TCf)can reach as high as-1114.3 ppm/℃ at a bias voltage equal to 90%of the collapse voltage of the *** corresponding nonlinear error was as low as 1.18%.It is discovered that the sensing sensitivity is dependent on the applied bias voltages.A higher sensitivity can be achieved by increasing the bias voltages.

关键词： Resonant temperature sensor CMUT finite element method bias voltages