检索结果-南通市图书馆

Cardiac nonrigid motion analysis from image sequences

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第10期16卷 1115-1118页

作者： LIU Huafeng (State Key Laboratory of modern Optical Instrumentation, Zhejiang university, Hangzhou 3.0027, china) State Key Laboratory of modern Optical Instrumentation Zhejiang University Hangzhou 310027 China

Noninvasive estimation of the soft tissue kinematics properties from medical image sequences has many important clinical and physiological implications, such as the diagnosis of heart diseases and the understanding of cardiac mechanics. In this paper, we present a biomechanics based strategy, framed as a priori constraints for the ill-posed motion recovery problems, to realize estimation of the cardiac motion and deformation parameters. By constructing the heart dynamics system equations from biomechanics principles, we use the finite element method to generate smooth estimates of heart kinematics throughout the cardiac cycle. We present the application of the strategy to the estimation of displacements and strains from in vivo left ventricular magnetic resonance image sequence.

关键词： cardiac motion and deformation continnum mechanics model finite element method.

Teleconnection between the Indian summer monsoon onset and the Meiyu over the Yangtze River Valley

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2008年第7期51卷 1021-1035页

作者： LIU YunYun1,2,3.& DING YiHui2 1 Chinese Academy of Meteorological Sciences, Beijing 100081, china 2 National Climate center, Beijing 100081, china 3.Graduate {3. of Chinese Academy of Sciences, Beijing 100049, china Chinese Academy of Meteorological Sciences Beijing China National Climate center Beijing China Graduate university of Chinese Academy of Sciences Beijing China

Based on the Indian and Chinese precipitation data and the NCEP-NCAR reanalysis circulation data, the relationship between the Indian summer monsoon (ISM) onset and the Meiyu over the Yangtze River Valley has been discussed by the methods of correlation analysis and composite analysis. The results show that the date of ISM onset over Kerala in the southwestern coast of the Indian Peninsula is about two weeks earlier than the beginning of the Meiyu over the Yangtze River Valley. After the outbreak of ISM, the teleconnection mode sets up from the western coast of India via the Bay of Bengal (BOB) to the Yangtze River Valley and southern Japan. It is different both in time and space from the telecon- nection mode which is from the northwest of India via the Tibetan Plateau to northern {3.. The for- mer mode is defined as the "south" teleconnection of the Asian summer monsoon, forming in the pe- riod of ISM onset; while the latter mode is called the "north" teleconnection, mainly occurring in the Asian monsoon culminant period. During the process of the "south" teleconnection’s formation, the Asian monsoon circulation has experienced a series of important changes: ISM onset, the northward movement of the south Asia high (SAH), the onset vortex occurrence, the eastward extension of the stronger tropical westerly belt, and the northeastward jump of the western Pacific subtropical high (WPSH), etc. Consequently, since ISM sets up over Kerala, the whole Asian continent is covered by the upper SAH after about two weeks, while in the mid- and lower troposphere, a strong wind belt forms from the Arabian Sea via the southern India, BOB and the South {3. Sea (SCS), then along the western flank of WPSH, to the Yangtze River Valley and southern Japan. With the northward moving of the subtropical jet streams, the upper westerly jet stream and the low level jet have been coupled ver- tically over east Asia, while the Yangtze River Valley happens to locate in the ascending motion

关键词： Indian summer monsoon (ISM) the Meiyu over the Yangtze River Valley teleconnection mode

Phylogeographic analysis of human papillomavirus 58

在线全文

学校读者我要写书评

暂无评论

Science china(Life Sciences) 2009年第12期52卷 1164-1172页

作者： LI YanYun1, LI ZuoFeng2, HE YiFeng1, KANG Yu1, ZHANG XiaoYan1, CHENG MingJun1, ZHONG Yang2, 3. & XU CongJian1· 1 Obstetrics and Gynecology Hospital of Fudan university, Shanghai 200011, china 2 Shanghai Bioinformation Research center, Shanghai 20023., china 3.School of Life Sciences, Fudan university, Shanghai 20043., china Obstetrics and Gynecology Hospital of Fudan university Shanghai China Shanghai Bio-information Research center Shanghai China School of Life Sciences Fudan University Shanghai China

Human papillomavirus 58 (HPV58) is one type of HPV with high risk of causing cervical cancer. Unusually high prevalence of HPV58 has been reported in Asia, Africa and some other areas. However, due to the scattered distribution of global data, in addition to the lack of data of some HPV58 high-incidence nations and regions, like china's Mainland, a comprehensive analysis of the global geographical distribution of HPV58 remains blank so far. In this study, HPV58 from the human cervical cancer tissue was detected in china's Mainland, and 14 new HPV58-E6/L1 gene sequences were obtained. Moreover, phylogeographic analysis has been conducted combining the HPV58 sequences that have been deposited in GenBank since 1985. The study result shows that the sequences detected from the Shanghai, Jiangsu and Sichuan areas are homologous with those found in the past from Hong Kong and Xi'an, china, as well as Japan and other Southeast Asian areas. Furthermore, Western Africa is considered to be the "root" source of the HPV58 variant, while china's Mainland and Southeast Asia are "transit points" and the new sources of HPV58 after receiving the isolates from the "root" source; like HPV16 and HPV18, the HPV58 might also be one of the major HPV types associated with the development and spread of cervical cancer.

关键词： human papillomavirus 58 (HPV58) cervical cancer phylogeography molecular evolution

Anion coordination complex [ClPt(bpt)_4]Cl (bpt= N,N'-bis(3.pyridylmethyl)-2-thiourea)

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2009年第4期52卷 471-474页

作者： LI Xin1,LI Hui2,YU ShuYan1,4 & LI YiZhi3.1 Laboratory for Self-Assembly Chemistry,Department of Chemistry,Renmin university of china,Beijing 100872,china 2 School of Materials Science and Engineering,East china university of Science and Technology,Shanghai 20023.,china 3.State Key Laboratory of Coordination Chemistry,Coordination Chemistry Institute,nanjing university,nanjing 2.0093.china 4 State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 3.0002,china Laboratory for Self-Assembly Chemistry Department of Chemistry Renmin University of China Beijing China School of Materials Science and Engineering East China University of Science and Technology Shanghai China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fuzhou China State Key Laboratory of Coordination Chemistry Coordination Chemistry Institute Nanjing University Nanjing China

The anion coordination complex,[ClPt(bpt)4]Cl (bpt=N,N'-bis(3.pyridylmethyl)-2-thiourea),was synthesized and studied by X-ray crystal structure analysis,NMR and FAB mass spectra. In the solid state,the Pt(bpt)4 anion receptor adopts a cone conformation to bind the chloride anion through hydrogen bonds and electrostatic interaction in which the four branches of the thiourea ligands bind the chloride anion to form N-H…Cl-hydrogen bonds (3.49-3.81). The entraped chloride anion is situated above the Pt(Ⅱ) center at 3.52 . Further second-sphere coordination assemby from the Pt(bpt)4 core with 8 zinc(Ⅱ) tetraphenylporphyrins (ZnPr) is discussed.

关键词： anion coordination platinum(Ⅱ) complex supramolecular chemistry hydrogen bonds second-sphere coordination

Ab initio Structure Determination of [Co(NH_3._5Br]Br_2 Using Conventional X-ray Powder Diffraction

维普期刊数据库评论

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 Chemical Letters 1997年第7期8卷 647-648页

作者： Hong Xiang WU and Li Dun MA(center for analysis and Measuremnt, Fudan university, Shanghai, 20043.)(Project supported by the National Natural Science Foundation of {3.(NSFC) NO. 29573.98) center for analysis and Measurement Fudan University Shanghai 200433 China

The crystal structure of [Co(NH3.5Br]Br2 has been determined ab initio from the conventional X-ray powder diffraction data. The approximate structure with all 7 indeyendent non-H atoms was solved by direct methods. The final orthorhombic unit-cell parameters after Rietveld refinement are: a=13.6927, b=10.7071, c=6.9400A, V=1017.47A3. F3.=93.0.0075,43., M20=49, Z=4. Space group is Pnma. The structure agreement factors are: Rp=0.066,Rwp=0.090, RF=0.041, RB=0.042.

关键词： Br2 Using Conventional X-ray Powder Diffraction Ab initio Structure Determination of NH3

Preparation of Chelating Cellulose Filters and Their Application to the Separation and Enrichment of Trace Elements

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 1995年第4期11卷 299-305页

作者： LIU Chun-ming(Department of Changchun Normal College, Changchun,13.03.)GUO Yi-hang and ZHAO Xiao-liang(center for analysis and Testing, Northeast Normal university, Changchun, 13.024) DING Lan(center for analysis and Testing ,Jilin university, Changchun, CHANGCHUN NORMAL COLL DEPT CHEM CHANGCHUN 130032 PEOPLES R CHINA NE NORMAL UNIV CTR ANAL & TESTING CHANGCHUN 130024 PEOPLES R CHINA JILIN UNIV CTR ANAL & TESTING CHANGCHUN 130023 PEOPLES R CHINA

hreekinds of chelating cellulose filters were prepared and ten trace elements were preconcentrated simultaneously on the microcolumn that was filled with the chelating cellulose filters. Alkali and alkaline earth metal ions were quantitatively separated as matrix elements at the selected pH values. The microcolumn has high enrichment factors and recoveries.

关键词： Chelating cellulose Microcolumn Inductively coupled plasma atomic emission spectrometry Separation and enrichment

The study of two-color excitation upconversion of Pr(0.5)Yb(3.:ZBLAN

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2006年第2期49卷 169-177页

作者： CHEN Xiaobo1 & SONG Zengfu2 1. Applied Optics Beijing Area Major Laboratory, analysis and testing center, Beijing Normal university, Beijing 100875, {3. 2. Peking university, Physics School, Beijing 100871, {3. Applied Optics Beijing Area Major Laboratory Analysis and testing center Beijing Normal University Beijing China Physics School Peking University Beijing China

The excited state absorption upconversion of Pr(0.5)Yb(3.:ZBLAN glass material, under two-color excitation of the 960 nm semiconductor laser and the Xe lamp light simultaneously, is reported in this article. It was found that the upconversion emission spectra of 480.1, 519.0, 601.9 and 63..8 nm coincide with the common emission spectra. Meanwhile, the upconversion-excitation spectrum has three obvious peaks under two-color excitation, and they respectively correspond to the 856.0 nm upconversion ex-citation transition [1G4(Pr3.)→1I6(Pr3.) and 1G4(Pr3.)→3.1(Pr3.)], the 789.0 nm upconver-sion excitation transition 1G4(Pr3.)→3.2(Pr3.), and the 803.7 nm upconversion excitation transition 3.6(Pr3.)→1D2(Pr3.). The upconversion excitation transition 1G4(Pr3.)→1I6(Pr3.) is strong because its oscillator strength f = 23.040×10?6 is large, which results in a large peak appearing in the upconversion excitation spectrum. That is just the new interesting two-color excitation upconversion luminescence phenomenon of Pr(0.5)Yb(3.:ZBLAN induced by one laser and one continuous normal light simultaneously.

关键词： upconversion volumetric three-dimensional display two-color excitation.

Rietveld Quantitative analysis of Carbides Precipitation in Normalized-tempered 2.25Cr-1Mo-0.25V Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials Science) 2009年第6期24卷 922-926页

作者：张永涛张汉谦 School of Materials Science and Engineering Shanghai Jiaotong University Research Institute Baoshan Iron & Steel Co.Ltd.

The quantitative determination of the mass fractions of precipitates in steels is very difficult using traditional materials characterization techniques. The Rietveld full-pattern fitting algorithm was introduced to solve this problem. The precipitated multicomponents’ mass fraction of M3., MC, M7C3.and M23.6 were evaluated precisely and relatively quickly. It is found evolution of carbides apparently occurs during tempering at high temperatures, and a two-step transformation mechanism is proposed for M7C3.during early tempering treatment. The method is an effective way on the investigation of precipitation kinetics, which may play a promising role in propertities’ enhancement and design of the heat-resistant steels.

关键词： 2.25Cr-1Mo-0.25V steel rietveld quantitative analysis precipitates

Interaction of Alisols and Hemoglobin using spectroscopic and molecular modeling methods

在线全文

学校读者我要写书评

暂无评论

Interaction of Alisols and Hemoglobin using spectroscopic an...