全文获取类型
收费全文 | 1313篇 |
免费 | 45篇 |
国内免费 | 10篇 |
专业分类
化学 | 888篇 |
晶体学 | 14篇 |
力学 | 25篇 |
数学 | 176篇 |
物理学 | 265篇 |
出版年
2022年 | 10篇 |
2021年 | 24篇 |
2020年 | 21篇 |
2019年 | 19篇 |
2018年 | 19篇 |
2017年 | 12篇 |
2016年 | 30篇 |
2015年 | 31篇 |
2014年 | 19篇 |
2013年 | 64篇 |
2012年 | 70篇 |
2011年 | 105篇 |
2010年 | 52篇 |
2009年 | 36篇 |
2008年 | 75篇 |
2007年 | 84篇 |
2006年 | 69篇 |
2005年 | 67篇 |
2004年 | 65篇 |
2003年 | 46篇 |
2002年 | 40篇 |
2001年 | 23篇 |
2000年 | 20篇 |
1999年 | 15篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 14篇 |
1993年 | 16篇 |
1992年 | 19篇 |
1991年 | 9篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1985年 | 10篇 |
1984年 | 11篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 18篇 |
1978年 | 19篇 |
1976年 | 10篇 |
1975年 | 7篇 |
1974年 | 18篇 |
1973年 | 14篇 |
1972年 | 9篇 |
1971年 | 7篇 |
1970年 | 7篇 |
排序方式: 共有1368条查询结果,搜索用时 31 毫秒
1.
2.
Curtis T. Mcmullen 《Acta Mathematica》2003,191(2):191-223
3.
Curtis T. McMullen 《Journal of the American Mathematical Society》2003,16(4):857-885
This paper exhibits an infinite collection of algebraic curves isometrically embedded in the moduli space of Riemann surfaces of genus two. These Teichmüller curves lie on Hilbert modular surfaces parameterizing Abelian varieties with real multiplication. Explicit examples, constructed from L-shaped polygons, give billiard tables with optimal dynamical properties.
4.
Lisa A. Liotta Irene Medina Jennifer L. Robinson Po-Shen Pan Jennifer V.C. Johnston Fiona A. Curtis Shelli R. McAlpine 《Tetrahedron letters》2004,45(46):8447-8450
Described are the syntheses of 15 macrocyclic peptides designed to trap Holliday junctions (HJs) in bacteria during site-specific and homologous recombination. This leads to inhibiting bacterial growth. These second generation macrocycles were based on the C-2 symmetrical HJ. They were synthesized using a strategy that permits elucidation of the amino acid role in binding HJs. The syntheses of these macrocycles are an important step in the development of a new class of antibiotics. 相似文献
5.
Curtis Bennett Kathy J. Dempsey Bruce E. Sagan 《Journal of Algebraic Combinatorics》1994,3(3):261-283
We construct a family of partially ordered sets (posets) that are q-analogs of the set partition lattice. They are different from the q-analogs proposed by Dowling [5]. One of the important features of these posets is that their Whitney numbers of the first and second kind are just the q-Stirling numbers of the first and second kind, respectively. One member of this family [4] can be constructed using an interpretation of Milne [9] for S[n, k] as sequences of lines in a vector space over the Galois field F
q. Another member is constructed so as to mirror the partial order in the subspace lattice. 相似文献
6.
N J Curtis P J Dortmans J Ciuk 《The Journal of the Operational Research Society》2006,57(11):1300-1312
The essential first step of any OR investigation is to ensure that the ‘right problem’ is studied. Our approach is to propose a set of six ‘rights’ or questions whereby achievement against particular aspects of a problem space is made and these provide the basis for scoping the context, understanding the system, and proposing sound options to the decision-maker. This style of problem structuring is an essential element of the Defence problem domain, and especially so for the Land Force, where there exist multiple degrees of freedom for poorly defined problems in an environment of uncertainty and ambiguity. Central to this is performing conceptual rather than analytical modelling, as perturbations then provide a basis for exploring a space, rather than solving a problem. 相似文献
7.
Gabriel M. Rebeiz Curtis C. Ling David B. Rutledge 《International Journal of Infrared and Millimeter Waves》1989,10(8):931-936
An accurate monolithic power meter has been developed for millimeter-wave applications. The detector is a large-area Bismuth bolometer, integrated on a fused-Quartz substrate. It simply measures the temperature change caused by the absorption of millimeter-wave radiation. The power meter is simple to fabricate, inexpensive, and can be easily calibrated using a low-frequency network. The measured responsivity for a 50 bolometer, with an area of 1×1cm, at a bias of 1V. and a video modulation of 100Hz, is 1mV/W. The noise spectrum exhibits a 1/f rolloff till 1KHz, and is limited by the Johnson noise for higher frequencies. The NEP of the detector is 3WHz–1/2 at a video modulation of 1KHz. It is possible to decrease the current NEP by fabricating bolometers with higher responsivities. Possible application areas are absolute power calibration and localized power density measurements at millimeter and submillimeter wavelengths. 相似文献
8.
The Pd(OAc)2/O2/DMSO catalyst system displays impressive versatility in the aerobic oxidation of organic substrates, ranging from alcohols to olefins. This report details mechanistic insights into these reactions. Dimethyl sulfoxide (DMSO) plays no redox role in the chemistry, and kinetic experiments identify the turnover-limiting step as DMSO-promoted oxidation of palladium(0) by molecular oxygen. The "chemical oxidase" pathway characterized for this catalyst system holds great promise for the design of new aerobic oxidation reactions. 相似文献
9.
Douglas R. Hurst Kristen L. French April J. Angel Angela R. Williams Mary E. Rampey Tina S. Guion Kam W. Chan Camille M. Kassis Shannon L. Studer Martinez Charles F. Beam 《Journal of heterocyclic chemistry》1998,35(6):1357-1359
Several acetoacetanilides were trilithiated in excess lithium diisopropylamide, and the resulting polylithiated intermediates were regioselectively condensed with lithiated methyl salicylates followed by acid cyclization to substituted 4-oxo-N-aryl-4H-1-benzopyran-2-acetamides (benzopyranone-2-acetamides). 相似文献
10.