全文获取类型
收费全文 | 990篇 |
免费 | 17篇 |
国内免费 | 3篇 |
专业分类
化学 | 588篇 |
晶体学 | 4篇 |
力学 | 22篇 |
数学 | 145篇 |
物理学 | 251篇 |
出版年
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 17篇 |
2015年 | 13篇 |
2014年 | 11篇 |
2013年 | 57篇 |
2012年 | 41篇 |
2011年 | 53篇 |
2010年 | 20篇 |
2009年 | 24篇 |
2008年 | 21篇 |
2007年 | 33篇 |
2006年 | 33篇 |
2005年 | 28篇 |
2004年 | 27篇 |
2003年 | 24篇 |
2002年 | 35篇 |
2001年 | 16篇 |
2000年 | 28篇 |
1999年 | 17篇 |
1998年 | 14篇 |
1997年 | 8篇 |
1996年 | 19篇 |
1995年 | 23篇 |
1994年 | 19篇 |
1993年 | 11篇 |
1992年 | 12篇 |
1991年 | 7篇 |
1990年 | 23篇 |
1989年 | 15篇 |
1988年 | 17篇 |
1987年 | 8篇 |
1986年 | 21篇 |
1985年 | 22篇 |
1984年 | 16篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 15篇 |
1980年 | 15篇 |
1979年 | 16篇 |
1978年 | 16篇 |
1977年 | 15篇 |
1976年 | 12篇 |
1975年 | 22篇 |
1974年 | 20篇 |
1973年 | 21篇 |
1971年 | 8篇 |
1968年 | 6篇 |
排序方式: 共有1010条查询结果,搜索用时 15 毫秒
951.
Gade A Bazin D Becerril A Campbell CM Cook JM Dean DJ Dinca DC Glasmacher T Hitt GW Howard ME Mueller WF Olliver H Terry JR Yoneda K 《Physical review letters》2005,95(2):022502
We report on the first determination of the absolute B(E2;0+(1)-->2+(1)) excitation strength in the N=Z nucleus 72Kr. 72Kr is the heaviest N=Z nucleus for which this quantity has been measured and provides a benchmark in a region of the nuclear chart dominated by rapidly changing deformations and shapes mediated by the interplay of strongly oblate and prolate-driving orbitals. The deduced quadrupole deformation strength is in agreement with a variety of self-consistent models that predict an oblate shape for the ground state of 72Kr. Large-scale shell-model Monte Carlo calculations reproduce the experimental B(E2) value and link the result to the occupation of the deformation-driving g9/2 orbit. 相似文献
952.
We report an observation of the weak 6 1S0-6 3P0 transition in (171,173)Yb as an important step to establishing Yb as a primary candidate for future optical frequency standards, and to open up a new approach for qubits using the 1S0 and 3P0 states of Yb atoms in an optical lattice. 相似文献
953.
We investigated the recently discovered high temperature proton conductor BaCa1.18Nb1.82H0.2O8.83 by means of quasielastic neutron scattering (QENS) using cold and thermal neutrons. From the former experiment we were able
to propose models for the diffusion of the hydrogen whereas the latter measurement reveals the geometry of a localized motion
of the protons.
Paper presented at the 2nd Euroconference on Solid State Ionics, Funchal, Madeira, Portugal, Sept. 10–16, 1995 相似文献
954.
Burnham PM Cook MJ Gerrard LA Heeney MJ Hughes DL 《Chemical communications (Cambridge, England)》2003,(16):2064-2065
Metal 1,4,8,11,15,18,22,25-octakis(hexylsulfanyl)phthalocyanines exhibit a weak absorption band in the 450-600 nm region, leading to novel dyes that include the red lead metallated derivative that has been characterised by X-ray crystallography. 相似文献
955.
The title compound forms intermolecular zinc-nitrogen coordinated species in solution and self-assembles to form a coordination polymer in the solid state, the X-ray structure for which shows that the unit cell contains eight macrocycle units in two chains comprising both enantiomeric forms as ABBA/BAAB sequences. 相似文献
956.
Abe K Abe K Abe T Adam I Akimoto H Aston D Baird KG Baltay C Band HR Barklow TL Bauer JM Bellodi G Berger R Blaylock G Bogart JR Bower GR Brau JE Breidenbach M Bugg WM Burke D Burnett TH Burrows PN Calcaterra A Cassell R Chou A Cohn HO Coller JA Convery MR Cook V Cowan RF Crawford G Damerell CJ Daoudi M de Groot N de Sangro R Dong DN Doser M Dubois R Erofeeva I Eschenburg V Etzion E Fahey S Falciai D Fernandez JP Flood K Frey R Hart EL Hasuko K Hertzbach SS Huffer ME Huynh X Iwasaki M 《Physical review letters》2001,86(7):1162-1166
We present final measurements of the Z boson-lepton coupling asymmetry parameters A(e), A(mu), and A(tau) with the complete sample of polarized Z bosons collected by the SLD detector at the SLAC Linear Collider. From the left-right production and decay polar angle asymmetries in leptonic Z decays we measure A(e) = 0.1544+/-0.0060, A(mu) = 0.142+/-0.015, and A(tau) = 0.136+/-0.015. Combined with our left-right asymmetry measured from hadronic decays, we find A(e) = 0.1516+/-0.0021. Assuming lepton universality, we obtain a combined effective weak mixing angle of sin (2)theta(eff)(W) = 0.230 98+/-0.000 26. 相似文献
957.
[structure: see text]. Replacing the 17alpha-acetoxy substituent in an antiprogestational 17beta-acetyl-11beta-arylestra-4,9-dien-3-one by 3-hydroxypropyl significantly diminished glucocorticoid receptor binding with little effect on progestin receptor binding. 相似文献
958.
Kenneth R. Cook 《Applied Acoustics》1980,13(2):109-120
The three parts of this paper are to be published in three issues of Applied Acoustics. The present part discusses the experimental facilities of the measuring laboratory and gives details of tests conducted on ceiling specimens. In Part 2 the work on various types of roof component will be presented. In Part 3 will follow the results of tests carried out on the roof and ceiling components combined. It will also consider the ability of the roofing system to provide sound insulation, as a component of the whole building envelope, from typical external noise spectra. The availability of sound insulation values obtained by laboratory measurements does provide the building industry with guidance in building design, even though values for actual buildings may vary considerably from laboratory-measured values. 相似文献
959.
The problem of directed polymers on disordered hierarchical and hypercubic lattices is considered. For the hierarchical lattices the problem can be reduced to the study of the stable laws for combining random variables in a nonlinear way. We present the results of numerical simulations of two hierarchical lattices, finding evidence of a phase transition in one case. For a limiting case we extend the perturbation theory developed by Derrida and Griffiths to nonzero temperature and to higher order and use this approach to calculate thermal and geometrical properties (overlaps) of the model. In this limit we obtain an interpolation formula, allowing one to obtain the noninteger moments of the partition function from the integer moments. We obtain bounds for the transition temperature for hierarchical and hypercubic lattices, and some similarities between the problem on the two different types of lattice are discussed. 相似文献
960.
Kenneth R. Cook 《Applied Acoustics》1980,13(3):202-210
In the first part of this series of papers,2 tests carried out on the ceiling component of a roofing system were described. In this second part, the experiments conducted on various types of roof component are outlined. The effect of coupling the ceiling and roof components to form the complete roofing system will be the central theme of the third and final part. 相似文献