全文获取类型
收费全文 | 1758篇 |
免费 | 35篇 |
国内免费 | 6篇 |
专业分类
化学 | 1096篇 |
晶体学 | 8篇 |
力学 | 62篇 |
数学 | 102篇 |
物理学 | 531篇 |
出版年
2020年 | 23篇 |
2019年 | 18篇 |
2016年 | 27篇 |
2015年 | 19篇 |
2014年 | 34篇 |
2013年 | 75篇 |
2012年 | 53篇 |
2011年 | 84篇 |
2010年 | 53篇 |
2009年 | 41篇 |
2008年 | 66篇 |
2007年 | 48篇 |
2006年 | 57篇 |
2005年 | 32篇 |
2004年 | 41篇 |
2003年 | 26篇 |
2002年 | 51篇 |
2001年 | 46篇 |
2000年 | 40篇 |
1999年 | 37篇 |
1998年 | 26篇 |
1997年 | 26篇 |
1996年 | 37篇 |
1995年 | 40篇 |
1994年 | 31篇 |
1993年 | 35篇 |
1992年 | 31篇 |
1991年 | 32篇 |
1990年 | 22篇 |
1989年 | 24篇 |
1988年 | 21篇 |
1987年 | 27篇 |
1985年 | 33篇 |
1984年 | 25篇 |
1983年 | 26篇 |
1982年 | 21篇 |
1981年 | 30篇 |
1980年 | 35篇 |
1979年 | 25篇 |
1978年 | 22篇 |
1977年 | 25篇 |
1976年 | 20篇 |
1975年 | 18篇 |
1974年 | 20篇 |
1973年 | 23篇 |
1972年 | 16篇 |
1971年 | 16篇 |
1970年 | 29篇 |
1969年 | 23篇 |
1967年 | 18篇 |
排序方式: 共有1799条查询结果,搜索用时 15 毫秒
121.
Evgueni Riaplov John P Maier Dietmar Panten Pavel Rosmus 《Journal of Molecular Spectroscopy》2003,222(1):15-21
Mass selected C2S− ions have been co-deposited with neon to grow a matrix at 6 K. The and electronic absorption spectra of the linear CCS− anion have been identified with origin band at 10 606 and 22 273 cm−1, respectively. After exposure to UV radiation a new electronic transition of CCS is observed (origin band at 30 563 cm−1) in addition to its known band system. Ab initio calculations provide support for the symmetry assignment of the upper electronic states of CCS−, CCS and of the vibrational structure in the spectra. 相似文献
122.
Robert S. Maier 《Journal of statistical physics》2003,111(5-6):1027-1048
Several formulas for crossing functions arising in the continuum limit of critical two-dimensional percolation models are studied. These include Watts's formula for the horizontal-vertical crossing probability and Cardy's new formula for the expected number of crossing clusters. It is shown that for lattices where conformal invariance holds, they simplify when the spatial domain is taken to be the interior of an equilateral triangle. The two crossing functions can be expressed in terms of an equianharmonic elliptic function with a triangular rotational symmetry. This suggests that rigorous proofs of Watts's formula and Cardy's new formula will be easiest to construct if the underlying lattice is triangular. The simplification in a triangular domain of Schramm's bulk Cardy's formula is also studied. 相似文献
123.
124.
Eisenstein BI Ernst J Gladding GE Gollin GD Hans RM Johnson E Karliner I Marsh MA Plager C Sedlack C Selen M Thaler JJ Williams J Edwards KW Sadoff AJ Ammar R Bean A Besson D Zhao X Anderson S Frolov VV Kubota Y Lee SJ Poling R Smith A Stepaniak CJ Urheim J Ahmed S Alam MS Athar SB Jian L Ling L Saleem M Timm S Wappler F Anastassov A Eckhart E Gan KK Gwon C Hart T Honscheid K Hufnagel D Kagan H Kass R Pedlar TK Thayer JB von Toerne E Zoeller MM Richichi SJ Severini H Skubic P Undrus A Savinov V 《Physical review letters》2001,87(6):061801
Using 12.7 fb(-1) of data collected with the CLEO detector at CESR, we observed two-photon production of the cc states chi(c0) and chi(c2) in their decay to pi(+)pi(-)pi(+)pi(-). We measured gamma(gammagamma)(chi(c))xB(chi(c)-->pi(+)pi(-)pi(+)pi(-)) to be 75+/-13(stat)+/-8(syst) eV for the chi(c0) and 6.4+/-1.8(stat)+/-0.8(syst) eV for the chi(c2), implying gamma(gammagamma)(chi(c0)) = 3.76+/-0.65(stat)+/-0.41(syst)+/-1.69(br) keV and gamma(gammagamma)(chi(c2)) = 0.53+/-0.15(stat)+/-0.06(syst)+/-0.22(br) keV. Also, cancellation of dominant experimental and theoretical uncertainties permits a precise comparison of gamma(gammagamma)(chi(c0))/gamma(gammagamma)(chi(c2)), evaluated to be 7.4+/-2.4(stat)+/-0.5(syst)+/-0.9(br), with QCD-based predictions. 相似文献
125.
Porcelli TA Adamczak A Bailey JM Beer GA Douglas JL Faifman MP Fujiwara MC Huber TM Kammel P Kim SK Knowles PE Kunselman AR Maier M Markushin VE Marshall GM Mason GR Mulhauser F Olin A Petitjean C Zmeskal J;TRIUMF Muonic Hydrogen Collaboration 《Physical review letters》2001,86(17):3763-3766
Measurements of muon-catalyzed dt fusion ( d(mu)t-->4He + n + mu(-)) in solid HD have been performed. The theory describing the energy dependent resonant molecular formation rate for the reaction (mu)t + HD-->[(d(mu)t)pee](*) is compared to experimental results in a pure solid HD target. Constraints on the rates are inferred through the use of a Monte Carlo model developed specifically for the experiment. From the time-of-flight analysis of fusion events in 16 and 37 microg x cm(-2) targets, an average formation rate consistent with 0.897+/-(0.046)(stat)+/-(0.166)(syst) times the theoretical prediction was obtained. 相似文献
126.
Ammar R Bean A Besson D Davis R Kwak N Zhao X Anderson S Frolov VV Kubota Y Lee SJ Mahapatra R O'Neill JJ Poling R Riehle T Smith A Stepaniak CJ Urheim J Ahmed S Alam MS Athar SB Jian L Ling L Saleem M Timm S Wappler F Anastassov A Duboscq JE Eckhart E Gan KK Gwon C Hart T Honscheid K Hufnagel D Kagan H Kass R Pedlar TK Schwarthoff H Thayer JB von Toerne E Zoeller MM Richichi SJ Severini H Skubic P Undrus A Chen S Fast J Hinson JW Lee J Miller DH Shibata EI Shipsey IP Pavlunin V 《Physical review letters》2001,86(7):1167-1170
Using data recorded with the CLEO II and CLEO II.V detector configurations at the Cornell Electron Storage Rings, we report the first observation and mass measurement of the Sigma(*+)(c) charmed baryon, and an updated measurement of the mass of the Sigma(+)(c) baryon. We find M(Sigma(*+)(c))-M(Lambda(+)(c)) = (231.0+/-1.1+/-2.0) MeV, and M(Sigma(+)(c))-M(Lambda(+)(c)) = (166.4+/-0.2+/-0.3) MeV, where the errors are statistical and systematic, respectively. 相似文献
127.
The superconducting instabilities of the doped repulsive 2D Hubbard model are studied in the intermediate to strong coupling regime with the help of the dynamical cluster approximation. To solve the effective cluster problem we employ an extended noncrossing approximation, which allows for a transition to the broken symmetry state. At sufficiently low temperatures we find stable d-wave solutions with off-diagonal long-range order. The maximal T(c) approximately 150 K occurs for a doping delta approximately 20% and the doping dependence of the transition temperatures agrees well with the generic high- T(c) phase diagram. 相似文献
128.
129.
130.
A treatment of sites appropriate to fluid percolation in bond controlled processes results in sensitivity of breakup of the defender to the degree of size-correlation for three-dimensional networks. In strongly correlated lattices network control of invasion yields to a statistical treatment as a result of improved accessibility. 相似文献