检索结果-南通市图书馆

Growth of Carbon Encapsulated Long Nickel Nanorods on Bulk Nickel Substrate

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) 2011年第1期26卷 28-32页

作者：宾晓蓓 college of Resources & Environment Engineering Wuhan University of Technology

Carbon nanotube encapsulated nickel nanorods were catalytic grown via pyrolysis of oil on a bulk nickel wire substrate. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy were employed to characterize the as-prepared sample. The results show that, carbon nanotubes possess several microns in length, the filled metallic nickel nanorods with a uniform diameter of 35 nm were tightly encapsulated by the carbon capsules. The detailed formation mechanism for the carbon nanotubes encapsulated nickel nanorods were discussed briefly.

关键词： carbon nanotube nickel nanorod pyrolysis core-shell

Molecular dynamics simulations on the structures and properties of ε-CL-2.-based PBXs ——Primary theoretical studies on HEDM formulation design

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2007年第6期50卷 737-745页

作者： XU XiaoJuan1,2. XIAO JiJun1, HUANG Hui3, LI JinShan3 & XIAO HeMing1 1 department of chemistry, Nanjing University of Science and Technology, Nanjing 2.0094,{2. 2.department of chemistry, Yancheng Teacher’s college, Yancheng 2.4002.{2. 3 Institute of Chemical Materials,{2. Academy of Engineering Physics, Mianyang 62.900,{2. department of chemistry Nanjing University of Science and TechnologyNanjing 210094China department of chemistry Yancheng Teacher''s CollegeYancheng 224002China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900

Five polymer bonded explosives(PBXs)with the base explosive epsilon-CL-2.(hexanitrohexaazaisowurtzi-tane),the most important high energy density compound(HEDC),and five polymer binders(Estane 5703,GAP,HTPB,PEG,and F_(2.14))were *** dynamics(MD)method was employed to investigate their binding energies(E_(bind))2./PEG 2./ Estane5703 ≈ epsilon-CL-2./GAP 2./HTPB 2./F_(2.14).By pair correlation function g(r)analyses,hydrogen bonds and vdw are found to be the main interactions between the two *** elasticity and isotropy of PBXs based epsilon-CL-2. can be obviously improved more than pure epsilon-CL-2. *** is not by changing the molecular structures of epsilon-CL-2. for each binder to affect the *** safety and energetic properties of these PBXs are mainly influenced by the thermal capability(C_p^(deg))and density(p)of binders,respectively.

关键词： high energy density material (HEDM), hexanitrohexaazaisowurtzitane (CL-2.), polymer bonded explosives (PBXs), molecular dynamics (MD), compatibility, safety properties, mechanical properties, energetic properties

Algorithm of graph isomorphism with threedimensional DNA graph structures

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第2期15卷 86-89页

作者： LIU Guangwu 1,2., YIN Zhixiang 1,3, XU Jin1 and DONG Yafei1(1. department of Control Science and Engineering, Hua Zhong University of Science and Technology, Wuhan 430074, china 2. {2. of Transportation, Wuhan University of Technology, Wuhan 430063, china 3. department of Mathematics and Physics, Anhui University of Science and Technology, Huainan 2.2.01, china) department of Control Science and Engineering Hua Zhong University of Science and Technology Wuhan 430074 China. college of Transportation Wuhan University of Technology Wuhan 430063 China. department of Mathematics and Physics Anhui University of Science and Technology Huainan 232001 China

An algorithm for solving the graph isomorphism problem with 3-D DNA structures is proposed in this paper. The k-armed branched junction molecules are used to code k-degree vertices. Double stranded molecules are used to code edges. Then the molecules are mixed in a tube to be ligated. The result can be detected by gel electrophoresis. The time complexity of the algorithm is O(n2., where n is the number of vertices of the graph.

关键词： DNA computing DNA graph structure graph isomorphism

Phytoestrogen genistein decreases contractile response of aortic artery in vitro and arterial blood pressure in vivo

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第3期25卷 59-64页

作者： Hong-fang LI1,Long-de WANG2.Song-yi QU department of Physiology,Lanzhou Medical college,Lanzhou 730000 2.ffiliated Hospital,Gansu Chinese Medical college,Lanzhou 73002.,china department of Physiology Lanzhou Medical College Affiliated Hospital Gansu Chinese Medical College

AIM: To determine the mechanisms of effects of phytoestrogen genistein on the contracted rabbit aortic arteries in vitro, and observe the effect of genistein and 17-β estradiol on mean arterial pressure (MAP) in ovariectomized (OVX) rats. METHODS: (1) Strips of rabbit aortic smooth muscle were suspended in organ baths containing Kreb’s solution, and then isometric tension was measured. (2. Female mature Wistar rats underwent a bilateral ovariectomy (OVX). Sham-operated rats (SHAM) were used as controls. After administration of genistein (0.4 mg·kg-1·d-1, sc), 17-β estradiol (1 mg·kg-1·d-1, sc) or theirvehicle sesame oil for 2. d,MAP was measured. RESULTS: (1) Similar to 17-β estradiol, genistein could dose-dependently relax 40 mmol/L KCl-precontracted arterial strips. Incubation with Nω-L-nitro-arginine (L-NNA), methylene blue (MB), indomethacin, propranolol or endothelium removal did not affect relaxation induced by genistein. In calcium-free solution containing 0.01mmol/L egtazic acid (EGTA), genistein inhibited not only the first phase contraction induced by noradrenaline (NA), but also the second contraction induced by CaCl2. In addition, genistein could reduce the contractile responses of NA, KCl and CaCl2. and shift their cumulative concentration-response curves rightward. (2. MAP in OVX rats was significantlyhigher compared with that of SHAM rats. However,after chronically treatment with genistein or 17-β estradiol for 2. d the baseline MAP in OVX rats was reduced significantly. CONCLUSIONS: (1) The vasodilator effect of genistein in vitro is endothelium independent and not related to the nitric oxide, its mechanisms being probably due to inhibition of Ca2. influx through calcium channels in a noncompetitive manner and Ca2. release from intracellular store induced by NA. (2. Administration of genistein or 17-β estradiol can chronically decrease MAP in OVX rats.

关键词： genistein aorta smooth muscle muscle relaxation calciumchannel vascular endothelium blood pressure

Special magnetic phenomena in heavily doped La_(0.7-x)Dy_xSr_(0.3)MnO_3 system

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(Physics,Mechanics & Astronomy) 2008年第1期51卷 90-97页

作者： LIU Ning 1,2.,YAN GuoQing 1,3 ,CAI ZhiRang 1 ,PI Li 2.,ZHANG Bei 2.&TONG Wei 2.1 department of Physics,Suzhou college,Suzhou 2.4000,{2. 2.Structure Research Laboratory,University of Science and Technology of china,Hefei 2.002.,{2. 3 National Laboratory of Solid State Microstructures,Physics department,Nanjing University,Nanjing 2.0093,{2. 1. department of Physics Suzhou College Suzhou 234000 China 2. Structure Research Laboratory University of Science and Technology of China Hefei 230026 China 3. National Laboratory of Solid State Microstructures Physics Department Nanjing University Nanjing 210093 China

The magnetism in heavily Dy doped La0.7-xDyxSr0.3MnO3(0.40≤x≤0.70)system is studied in this *** M-T relation seems to be complicated with the increase of *** sample with x=0.40,AFM behavior exists at T≤TN and M-T curves under zero field cooling(ZFC)and field cooling(FC)exhibit typical behavior of spincluster glass state above *** the sample with x=0.50,the M-T curve under ZFC exhibits a valley at a low temperature while the M-T curve under FC exhibits the negative magnetization below *** samples with x=0.60,0.70,their ZFC M-T curves are similar to that of x=0.50,but the FC M-T curves do not exhibit negative values any *** the peculiar phenomena above are well explained by Néel double-lattice model combined with M-H relation at typical *** molecular field theory fits well the negative magnetization for x=0.50.

关键词： heavily doped special magnetic phenomena double-lattice model

Orientation angle rotatability of planar serial n-link manipulators

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第6期53卷 1620-1637页

作者： LI RuiQin1,XIAO DengHong1 & DAI Jian S2.1 college of Mechanical Engineering and Automation,North University of china,Taiyuan 030051,{2. 2.department of Mechanical Engineering,King’s college London,University of London,London WC2. 2.S,UK 1. college of Mechanical Engineering and Automation North University of China Taiyuan 030051 China2. Department of Mechanical Engineering King’s College London University of London London WC2R 2LS UK

This paper presents a new method of analyzing the orientation angle rotatability of a planar serial n-link manipulator by examining the rotatability of its virtual equivalent *** orientation boundary region decomposition is proposed based on the polynomial discriminant derived from a serial three-link *** angle workspace indicates a set of angle ranges by which the end-effector can reach with certain orientation for every point in the reachable position *** introducing a virtual equivalent mechanism,the open-chain kinematic problem is converted into a close-chain mechanism,and the Grashof-type condition is used to examine the rotatability of the end-effector *** reachable position workspace can be divided into several Grashof intervals and non-Grashof intervals based on the extreme positions and singular configurations of a *** derived equations in this paper can be used to calculate the variation rule of the orientation angle workspace of any given planar serial n-link manipulator on the basis of its link *** orientation angle rotatability of a seven-link serial manipulator is solved by the proposed method and graphical representations of the orientation angle workspaces are mapped onto a three-dimensional coordinate *** theoretical approach has practical significance for the design of a highly dexterous serial n-link manipulator with proposed link relations.

关键词： Grashof criterion planar serial manipulator orientation angle workspace virtual equivalent mechanism

Piecewise-Koszul algebras

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2007年第12期50卷 1795-1804页

作者： Jia-feng L■~1 Ji-wei HE~2.Di-ming LU~(1+) ~1 department of Mathematics,Zhejiang University,Hangzhou 31002.,china ~2.department of Mathematics,Shaoxing college of Arts and Sciences,Shaoxing 312.00,china department of Mathematics Zhejiang University Hangzhou 310027 China department of Mathematics Shaoxing College of Arts Sciences Shaoxing 312000 China

It is a small step toward the Koszul-type *** piecewise-Koszul algebras are, in general,a new class of quadratic algebras but not the classical Koszul ones,simultaneously they agree with both the classical Koszul and higher Koszul algebras in special *** give a criteria theorem for a graded algebra A to be piecewise-Koszul in terms of its Yoneda-Ext algebra E(A),and show an A_∞-structure on E(A).Relations between Koszul algebras and piecewise-Koszul algebras are *** particular,our results are related to the third question of Green-Marcos.

关键词： (d-)Koszul algebras A_∞-algebras Yoneda-Ext algebras

Metallomics:An integrated biometal science

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2009年第12期52卷 2055-2070页

作者： GE RuiGuang1,2.& SUN HongZhe1 1 department of chemistry and Open Laboratory of Chemical Biology,The University of Hong Kong,Hong Kong,{2. 2.Laboratory of Integrative Biology,college of Life Sciences,Sun Yat-Sen University,Guangzhou 510006,{2. department of chemistry and Open Laboratory of Chemical Biology The University of Hong Kong Hong Kong China Laboratory of Integrative Biology College of Life Sciences Sun Yat-Sen University Guangzhou 510006 China

Metallomics is an emerging scientific area integrating the research fields related to the understanding of the molecular mechanisms of metal-associated life processes and the entirety of metal and metalloid species within a cell or tissue type. In metallomics,metalloproteins,metalloenzymes and other metal-containing biomolecules in a biological system are referred to as metallomes,similar to genomes and proteomes in genomics and proteomics,respectively. This review discusses the concept of metallomics with a focus on analytical techniques and methods,particularly the so-called hyphenated techniques which combine a high-resolution separation technique (gel electrophoresis/laser ablation,chromatography or capillary electrophoresis) with a highly sensitive detection method such as elemental (inductively coupled plasma,ICP) or molecular (electron spray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI)) mass spectrometry,or nuclear X-ray fluorescence/absorption spectrometry. The applications of these advanced analytical methods in the identification of metallo-/phospho-/seleno-proteins,probing of relationships between structure and function of metal-loproteins,and study of clinically used metallodrugs will be selectively outlined,along with their advantages and limitations.

关键词： metallomics metallome metallodrug metalloprotein chemical speciation

Grey Markov chain and its application in drift prediction model of FOGs

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2005年第2期16卷 388-393页

作者： Fan Chunling 1,2., Jin Zhihua1, Tian Weifeng1 & Qian Feng11. department of Information Measurement Technology and Instrument, Shanghai Jiaotong University,Shanghai 2.0030, P. R. china 2. {2. of Automation and Electric Engineering, Qingdao University of Science and Technology,Qingdao 2.6042. P. R. china department of Information Measurement Technology and Instrument Shanghai Jiaotong University Shanghai 200030 P. R. China college of Automation and Electric Engineering Qingdao University of Science and Technology Qingdao 266042 P. R. China

A novel grey Markov chain predictive model is discussed to reduce drift influence on the output of fiber optical gyroscopes (FOGs) and to improve FOGs' measurement precision. The proposed method possesses advantages of grey model and Markov chain. It makes good use of dynamic modeling idea of the grey model to predict general trend of original data. Then according to the trend, states are divided so that it can overcome the disadvantage of high computational cost of state transition probability matrix in Markov chain. Moreover, the presented approach expands the applied scope of the grey model and makes it be fit for prediction of random data with bigger fluctuation. The numerical results of real drift data from a certain type FOG verify the effectiveness of the proposed grey Markov chain model powerfully. The Markov chain is also investigated to provide a comparison with the grey Markov chain model. It is shown that the hybrid grey Markov chain prediction model has higher modeling precision than Markov chain itself, which prove this proposed method is very applicable and effective.

关键词： grey model Markov chain FOG drift.