全文获取类型
收费全文 | 199篇 |
免费 | 1篇 |
专业分类
化学 | 102篇 |
晶体学 | 1篇 |
力学 | 13篇 |
数学 | 18篇 |
物理学 | 66篇 |
出版年
2022年 | 2篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 8篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 13篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 1篇 |
1982年 | 10篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有200条查询结果,搜索用时 15 毫秒
71.
The effectiveness of steering in simple dissociation reactions has been studied by performing classical and quantum simulations on a wide range of model potentials. By parametrically varying the PES landscape, it is shown how trends in the translational energy dependence of the dissociation probability may be related to particular topographical features. The relationship between the strength of attractive and repulsive regions determines the force which a molecule feels, but in addition we show that the range of the force helps determine the degree of repositioning and reorientation. The presence of wells along the reaction coordinate is considered, and it is shown how the snarled trajectories which frequently result relate to precursor-like behaviour even in the absence of dissipative processes. 相似文献
72.
73.
74.
Liverton NJ Holloway MK McCauley JA Rudd MT Butcher JW Carroll SS DiMuzio J Fandozzi C Gilbert KF Mao SS McIntyre CJ Nguyen KT Romano JJ Stahlhut M Wan BL Olsen DB Vacca JP 《Journal of the American Chemical Society》2008,130(14):4607-4609
Molecular modeling of inhibitor bound full length HCV NS3/4A protease structures proved to be a valuable tool in the design of a new series of potent NS3 protease inhibitors. Optimization of initial compounds provided 25a. The in vitro activity and selectivity as well as the rat pharmacokinetic profile of 25a compare favorably with the data for other NS3/4A protease inhibitors currently in clinical development for the treatment of HCV. 相似文献
75.
Zuo T Walker K Olmstead MM Melin F Holloway BC Echegoyen L Dorn HC Chaur MN Chancellor CJ Beavers CM Balch AL Athans AJ 《Chemical communications (Cambridge, England)》2008,(9):1067-1069
Although there are 51 568 non-IPR and 24 IPR structures for C84, the egg-shaped endohedral fullerenes Tm3N@C(s)(51 365)-C84 and Gd3N@C(s)(51 365)-C84 utilize the same non-IPR cage structure as found initially for Tb3N@C(s)(51 365)-C84. 相似文献
76.
Chaur MN Melin F Elliott B Athans AJ Walker K Holloway BC Echegoyen L 《Journal of the American Chemical Society》2007,129(47):14826-14829
High-performance liquid chromatography was used to isolate two new trimetallic nitride endohedral fullerenes, Gd3N@C2n (n = 42 and 44), and they were characterized by MALDI-TOF mass spectrometry, UV-vis-NIR, and cyclic voltammetry. It was found that their electronic HOMO-LUMO gaps depend pronouncedly on the size of the cage, from a large band gap for Gd3N@C80 (2.02 V) to a small band gap for Gd3N@C88 (1.49 V). The electrochemical properties also change dramatically with the size of the cage, going from irreversible for the C80 cage to reversible for Gd3N@C88. The latter is the largest trimetallic cluster inside C88 isolated and characterized to date. Gd3N@C88 has one of the lowest electrochemical energy gaps for a nonderivatized metallofullerene. 相似文献
77.
This review covers almost 290 heterobinuclear Pt derivatives. When the heterometals (M) are non transition and the binuclear
are found both with and without a metal to metal bond. Where M is a transition metal or actinide, only those with a metal-metal
bond have been included here. There are thirteen non-transition metals (Sn, Hg, Ge, Sb, Tl, Zn, Pb, Cd, Na, K, Ga, Ca and
In). The shortest Pt-M bond distance is 235.2(1) (Pt-Ge). There are eighteen transition metals (Fe, W, Rh, Re, Pd, Ag, Ir,
Mo, Mn, Re, Co, Cu, Cr, Au, Ni, Ti, Ta and V). The shortest Pt-M bond distance is 249.5(2) pm (Pt-Cr). There is one example
of an actinide, Pt-Th at 298.4(1) pm. The Pt atom has oxidation numbers 0, +2 and +4. The Pt coordination geometries include
square planar (most common), trigonal bipyramidal, pseudo octahedral (Pt(IV)) and a few prevalently capped trigonal prismatic
seven coordinate species. There are at least two types of isomerism distortion and polymerisation. Factors affecting bond
lengths and angles are discussed and some ambiguities in coordination polyhedra are outlined.
相似文献
78.
van Berkel C Gwyer JD Deane S Green NG Green N Holloway J Hollis V Morgan H 《Lab on a chip》2011,11(7):1249-1255
Counting the different subpopulations of cells in a fingerprick of human blood is important for a number of clinical point-of-care (PoC) applications. It is a challenge to demonstrate the integration of sample preparation and detection techniques in a single platform. In this paper we demonstrate a generic microfluidic platform that combines sample processing and characterisation and enumeration in a single, integrated system. Results of microfluidic 3-part differential leukocyte (granulocyte, lymphocyte and monocyte) counts, together with erythrocyte and thrombocyte (platelet) counts, in human blood are shown and corroborated with results from hospital clinical laboratory analysis. 相似文献
79.
Milan Melnik Ondrej Sprusansky Clive E. Holloway 《Central European Journal of Chemistry》2012,10(6):1709-1759
This review covers almost two hundred and twenty heterobinuclear platinum compounds in which Pt?M separation is over 3.0 ?. The M is a transition metal (Cu, Ag, Au, Ti, V, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni and Pd). There is an example of a lanthanide, Yb and a actinide, U. The Pt atom has oxidation numbers 0, +2 and +4. The Pt coordination geometries include trigonal planar Pt(0); square planar Pt(II); trigonal bipyramidal, and pseudo octahedral Pt(IV), with the most frequent being square planar. The most common ligands for Pt are P and C donor atoms, as well as a chlorine atom. The Pt ?? Ag distance of 3.002(1) ? is the shortest found in this series. There are examples which contain two crystallographically independent molecules, which differ mostly by degree of distortion and even one unique example, which contains eight such molecules. These are examples of distortion isomerism. Factors affecting bond lengths and angles are discussed and some ambiguities in coordination polyhedral are outlined. 相似文献
80.
Charles A. Holloway 《Mathematical Programming》1974,6(1):14-27
The Frank and Wolfe method of feasible directions is shown to be a case of the more general computational approach of inner linearization followed by restriction. An extension is proposed based on this observation. The extended procedure converges, and under certain conditions the asymptotic convergence rate is geometric. Limited computational experience comparing the two procedures is reported.The author is grateful to Mr. Peter Friesen for help with the computational work and to the Graduate School of Business, Stanford University for their support of this research. 相似文献