检索结果-南通市图书馆

china CDC weekly 2024年第11期6卷 203-207,I0001-I0003页

作者： Chi Shen xi Chen School of Public Policy and Administration Xi’an Jiaotong UniversityXi’an CityShaanxi ProvinceChina Department of Health Policy and Management Yale School of Public HealthNew HavenCTU.S Department of Economics Yale UniversityNew HavenCTU.S

What is already known about this topic?There is mounting evidence indicating that the aging process initiates during early life stages,with in utero the individual’s environment playing a significant ***,it is crucial to comprehend the enduring effects of early life circumstances on health in old *** is added by this report?In this study,we conducted a meta-analysis to examine the effects of the Chinese Famine(1959–1961)on the health of older *** also explored potential mechanisms underlying these *** are the implications for public health practice?The complex interplay between early life circumstances,multiple health-related sectors,and healthy aging necessitates a comprehensive life-course approach and strategic interventions to enhance public health in an aging society.

关键词： life aging mount

Synthesis of Monodisperse Poly(chloromethylstyrene divinylbenzene)Particle and Its Applications

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 1998年第11期9卷 0-0,0-0页

作者： Yin Mao WEI xin Du GENG (Institute of modern Separation Science, Key Laboratory of modern Separation Science in Shaanxi Province, northwest university, xi’an 710069) Inst. of modern Separation Science Key Lab. Modem Separation Sci. S.P. Northwest University Xi'an 710069 China

Monodisperse poly (chloromethylstyrene divinylbenzene) particles were prepared by a two-step swelling method. It was demonstrated that the packings have comparative advantages for biopolymer separation with high column efficiency, low interstitial volume and low back pressure to the packings prepared with suspension polymerization method. Using size exclusionchromatography and weak ion exchange chromatography as examples, it was shown that these packings could be modified chemically more easily than poly (styrene divinylbenzene) packings.

关键词： Monodisperse poly (chloromethylstyrene divinylbenzene) particles synthesis size exclusion chromatography weak cation exchange chromatography rotein separation

Electronic structure and magnetism of Fe-doped SiC nanotubes

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2010年第9期53卷 1582-1589页

作者： ZHANG WeiHu1,2,3,ZHANG FuChun3,ZHANG ZhiYong4,LU ShuYuan5 & YANG YanNing3 1 xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,xi’an 710068,china 2 Graduate university of Chinese Academy of Sciences,Beijing 100049,china 3 College of physics and Electronic Information,Yan’an university,Yan’an 716000,china 4 Information Science and Technology Institution,northwest university,xi’an 710127,china 5 Department of Telecommunications,xi’an Institute of Posts and Telecommunications,xi’an 710121,china xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an China Graduate university of Chinese Academy of Sciences Beijing China College of physics and Electronic Information Yan’an University Yan’an China Information Science and Technology Institution Northwest University Xi’an China Department of Telecommunications Xi’an Institute of Posts and Telecommunications Xi’an China

The electronic structure and magnetic properties of Fe-doped SiC nanotubes are investigated by using the first-principles method based on density functional theory(DFT) in the local spin density approximation(LSDA).The calculation results indicate that the SiC nanotube of Fe substitution for C exhibits antiferromagnetism while ferromagnetism features prominently when Fe substitutes *** is a kind of half-metal magnetic *** formation energy calculation results show that the formation energy of ferromagnetic structure is 3.2 eV lower than that of antiferromagnetic *** atoms are more likely to replace Si ***-orbit coupling induces electron spin polarization in the ground ***,the doping Fe atoms make relaxation towards the outside of the tube to some extent and larger geometric distortion occurs when Fe substitutes C,but the whole geometric structure of SiC nanotubes is not damaged due to the *** is revealed in the calculation of energy band structure and density of states that more dispersed distribution of energy levels is produced near the Fermi *** Fe substitution for Si,obviously there are spin-split and intense p-d hybrid effects by Si 3p electron spins and Fe 3d electron spins localized at the exchanging interactions between magnetic transitional metal(TM) *** electronic density results indicate that system magnetic moments are mainly generated by the unpaired 3d electrons of Fe *** these results show that the transition metal doping SiC nanotube could be a potential route to fabricating the promising magnetic materials.

关键词： SiC nanotube the first-principles doped magnetic properties

STUDIES　ON　THE　DETERMINATION　METHOD　OF　TRACE　ELEMENTS　IN　THE　FOSSIL　OF　DINOSAURIANEGG（Ⅰ）

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1996年第8期7卷 733-734页

作者： Hong Tao YAN and Sheng Ke YANG(Department of Chemistry, northwest university, xi’an, 710069) Department of Chemistry Northwest University Xi'an 710069

A new method for the determination of trace iridium with catalytic theer thermallensing spectrometry was developed. The method has been applied to the determination ofthe trace iridium in the fossil of dinosaurian egg...

关键词：

Preface to the Special Issue in Celebration of Professor Shouwen Yu’s 85th Birthday

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第3期37卷 361-362页

作者： xi-Qiao Feng Qunyang Li Department of Engineering Mechanics Tsinghua UniversityBeijing100084China

Shouwen Yu,Emeritus Professor of Applied Mechanics at Tsinghua university,was born on May 4,1939 in xianyou County,Fujian Province,*** pursued his undergraduate studies from 1955 to 1958 in the Department of Civil Str... 详细信息

关键词： Fujian Preface pursue

TECTONIC SIGNIFICANCE OF THE WEST KUNLUN FOLD-THRUST-BELT AND THE TARIM SOUTHWEST DEPRESSION

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

地学前缘 2000年第S1期7卷 84-86页

作者： Luo Jinhai (Department of Geology, northwest university, xi′an 710069,china)

The evolution of the Tarim southwest depression lying at the piedmont of the West Kunlun orogen differs completely from the evolution of the main part of Tarim basin after Later Palaeozoic because the former strongly subsides many times.. Subsidence is related closely to the West Kunlun fold thrust\|belt, thus the evolution of the Depression and the fold\|thrust\|belt reflects clearly the formation and evolution of the West Kunlun and even the Tibet.1 Evolution of the West Kunlun fold\|thrust\|belt\;Thrusting of the fold\|thrust\|belt can be classified into three stages:(1) Devonian thrusting:This is the oldest thrusting distinguished in the northern margin of the West Kunlun while the Silurian—Devonian thrusting was discriminated a few years ago by seismic data in the northern part of the East Kunlun. The Devonian thrusting is proved by the Upper Devonian dynamometamorphic rocks outcropping at the core of the anticline in the Sangzhu lying at the fold\|thrust\|belt. The rocks consist of slightly metamorphic clastic rock and have always been regarded as the Mid\|Proterozoic strata. But they are actually Upper Devonian strata according to the amount of perfect plant fossils that we found recently in the metamorphic rock, and they are overburdened `with an angular unconformity by another reliable Upper\|Devonian conglomerate in the core of the Aqike anticline. A possible explanation for this and its limited lined distribution parallel to the West Kunlun orogen is that they are subjected to metamorphism during the Later Devonian thrusting.

关键词： evolution West Kunlun fold\|thrust\|belt Tarim southw est depression correspondence

Capture Efficiency Analysis in the Circular Restricted Three-body Problem

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第5期24卷 198-210页

作者： Yu-Xuan Miao xi-Yun Hou Department of Astronomy and Space Science Nanjing UniversityNanjing 210023China Institute of Space Environment and Astrodynamics Nanjing UniversityNanjing 210023China Key Laboratory of modern Astronomy and Astrophysics Ministry of EducationNanjing 210023China

Temporary capture efficiency is studied in the framework of the circular restricted three-body problem in two ***, a non-uniform distribution of test particles around the secondary's orbit is obtained by fully accounting the secondary's gravitational influence. Second, the capture efficiency is computed based on the non-uniform distribution. Several factors influencing the result are discussed. By studying the capture efficiency in the circular restricted three-body problem of different mass ratios, a power-law relation between the capture efficiency(p) and the mass ratio(μ) is established, which is given by p ≈ 0.27 × μ^(0.53), within the range of 3.0035 ×10^(-6)≤ μ ≤ 3.0034 × 10^(-5). Taking the Sun–Earth system as an example, the influence from the orbit eccentricity of the secondary on the non-uniform distribution and the capture efficiency is studied. Our studies find that the secondary's orbit eccentricity has a negative influence on the capture efficiency.

关键词： methods numerical-celestial mechanics-planets and satellites dynamical evolution and stability

Synthesis of GoldMag particles with assembled structure and their applications in immunoassay

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2006年第6期49卷 534-540页

作者： CUI Yali1, ZHANG Lianying1, SU Jing1, ZHANG Caifeng3, LI Qi2, CUI Ting3, JIN Boquan2 & CHEN Chao1,3 1. Biochip Research and Development Center, northwest university (National Engineering Research Center for Miniaturized Detection System), xi’an 710069, china 2. Department of Immunology, The Fourth Military Medical university, xi’an 710032, china 3. Shaanxi Lifegen Co., Ltd., xi’an 710069, china Biochip Research and Development Center Northwest University (National Engineering Research Center for Miniaturized Detection System) Xi’an China Shaanxi Lifegen Co. Ltd. Xi’an China Department of Immunology The Fourth Military Medical University Xi’an China

Micrometer-sized Fe3O4 particles and nano-sized gold particles were first synthesized by methods of self-aggregation of surface-chemically modified Fe3O4 nanoparticles and citrate reduction of the Au3+ to Au0, respectively. Interaction between these two types of particles resulted in the assembly of nano-sized gold particles on the surface of the micrometer-sized Fe3O4 particles, forming an assembled structure with the Fe3O4 core particles around which are attached nano-sized gold parti- cles. The Fe3O4/Au structure is named GoldMag particles with assembled structure. The synthetic process, structure, and magnetic property of the GoldMag particles were analyzed. GoldMag particles with assembled structure have an irregular shape, rough surface with a diameter of 2―3 μm. These particles exhibit the superparamagnetic property with saturated magnetization of 41 A·m2/kg. In a single step, antibodies could be readily immobilized onto the surface of the particles with a high binding capacity. The GoldMag particles can be used as a novel carrier in immunoassays. The maximum quantity of human IgG immobilized onto GoldMag particles was 330 μg/mg. In order to validate the quality of the GoldMag particles as immunoassay carriers, an immunoassay system was used. The relative amount of immobilized human IgG was measured by HRP-labeled anti human IgG. The coefficient of variation within parallel samples of each group was below 6% and the coefficient of variation of means between five groups carried out separately was below 7%. Based on the sandwich method, the Hepatitis B surface antigen (HBsAg) and interleukin-8 (IL-8) were also analyzed by qualitative and quantitative detection, respectively. The result indicated that the GoldMag particles with assembled structure were an ideal carrier in immunoassay.

关键词： GoldMag particles with assembled structure, synthesis, carrier, immunoassay.

Free Volume Changes in γ-Irradiated Polyethylene and Polytetraflourethylene

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2000年第3期16卷 302-304页

作者： xianyi ZHOU (Dept. of modern physics, university of Science and Technology of china, Hefei 230027, china) Linhua ZHAI (Department of physics, Anhui Normal university, Wuhu 241000, china) Jiangfeng DU and Rongdian HAN (Department of modern physics, Univers Department of modern physics University of Science and Technology of China Hefei 230027 China Department of physics Anhui Normal University Wuhu 241000 China

Positron lifetime spectrum was measured and the change of the free volume was studied for commercial polyethylene (PE) and polytetrafluoroethylene (PTFE) during 7-irradiation processing up to 265 kGy. The free volume size increases but the crystallinity decreases as irradiation dose increases in PE. Both qualities (free volume size and crystallinity) in PTFE display an opposite behavior. The fractional free volume reduces monotonically with increasing irradiation dose in both PE and PTFE. The competition between the crosslinkmg and the splitting decomposition in polymers can be used to understand the free volume changes with irradiation dose.

关键词： PTFE Irradiated Polyethylene and Polytetraflourethylene

The essential ability of sparse reconstruction of different compressive sensing strategies

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2012年第11期55卷 2582-2589页

作者： ZHANG Hai1,2,LIANG Yong3,GOU HaiLiang1 & XU ZongBen1 1 Institute for Information and System Science,xi'an Jiaotong university,xi'an 710049,china 2Department of Mathematics,northwest university,xi'an 710069,china 3university of Science and Technology,Macau 999078,china Institute for Information and System Science Xi’an Jiaotong University Xi’an China Department of Mathematics Northwest University Xi’an China university of Science and Technology Macau China

We show the essential ability of sparse signal reconstruction of different compressive sensing strategies,which include the L1 regularization,the L0 regularization(thresholding iteration algorithm and OMP algorithm),the Lq(0 < q ≤ 1) regularizations,the Log regularization and the SCAD *** phase diagram as the basic tool for analysis,we find that(i) the solutions of the L0 regularization using hard thresholding algorithm and OMP algorithm are similar to those of the L1 regularization;(ii) the Lq regularization with the decreasing value of q,the Log regularization and the SCAD regularization can attain sparser solutions than the L1 regularization;(iii) the L1/2 regularization can be taken as a representative of the Lq(0 < q < 1) *** 1/2 < q < 1,the L1/2 regularization always yields the sparsest solutions and when 0 < q < 1/2 the performance of the regularizations takes no significant *** results of this paper provide experimental evidence for our previous work.

关键词： compressive sensing regularization sparsity L1/2 regularization