全文获取类型
收费全文 | 78964篇 |
免费 | 344篇 |
国内免费 | 378篇 |
专业分类
化学 | 24569篇 |
晶体学 | 800篇 |
力学 | 6774篇 |
数学 | 32064篇 |
物理学 | 15479篇 |
出版年
2020年 | 35篇 |
2019年 | 32篇 |
2018年 | 10466篇 |
2017年 | 10286篇 |
2016年 | 6104篇 |
2015年 | 871篇 |
2014年 | 321篇 |
2013年 | 387篇 |
2012年 | 3829篇 |
2011年 | 10535篇 |
2010年 | 5659篇 |
2009年 | 6080篇 |
2008年 | 6617篇 |
2007年 | 8793篇 |
2006年 | 259篇 |
2005年 | 1337篇 |
2004年 | 1560篇 |
2003年 | 1998篇 |
2002年 | 1033篇 |
2001年 | 264篇 |
2000年 | 306篇 |
1999年 | 164篇 |
1998年 | 205篇 |
1997年 | 155篇 |
1996年 | 209篇 |
1995年 | 124篇 |
1994年 | 90篇 |
1993年 | 100篇 |
1992年 | 63篇 |
1991年 | 72篇 |
1990年 | 58篇 |
1989年 | 59篇 |
1988年 | 63篇 |
1987年 | 66篇 |
1986年 | 61篇 |
1985年 | 54篇 |
1984年 | 51篇 |
1983年 | 45篇 |
1982年 | 50篇 |
1981年 | 46篇 |
1980年 | 56篇 |
1979年 | 52篇 |
1978年 | 42篇 |
1973年 | 33篇 |
1914年 | 45篇 |
1913年 | 40篇 |
1912年 | 40篇 |
1909年 | 41篇 |
1908年 | 40篇 |
1907年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Lu Feng Yun-He Li Fei Yu Jing-Fei Zhang Xin Zhang 《The European Physical Journal C - Particles and Fields》2018,78(10):865
The model of holographic dark energy in which dark energy interacts with dark matter is investigated in this paper. In particular, we consider the interacting holographic dark energy model in the context of a perturbed universe, which was never investigated in the literature. To avoid the large-scale instability problem in the interacting dark energy cosmology, we employ the generalized version of the parameterized post-Friedmann approach to treating the dark energy perturbations in the model. We use the current observational data to constrain the model. Since the cosmological perturbations are considered in the model, we can then employ the redshift-space distortions (RSD) measurements to constrain the model, in addition to the use of the measurements of expansion history, which has never been done in the literature. We find that, for both the cases with \(Q=\beta H\rho _\mathrm{c}\) and with \(Q=\beta H_0\rho _\mathrm{c}\), the interacting holographic dark energy model is more favored by the current data, compared to the holographic dark energy model without interaction. It is also found that, with the help of the RSD data, a positive coupling \(\beta \) can be detected at the \(2.95\sigma \) statistical significance for the case of \(Q=\beta H_0\rho _\mathrm{c}\). 相似文献
992.
Wei Xu 《The European Physical Journal C - Particles and Fields》2018,78(10):871
We present the exact anyon solutions and study their energy conditions. It is shown that the exact anyon VdW solutions with \(b>0\) are physically un-acceptable. Especially for the reduced case \(b=0\), after carefully studying its energy conditions, geometric quantities and horizon structure, we conclude that there is an anyon black hole taking the precisely same thermodynamical phase space with the gas of “interacting point particle” (IPP), which should exhibit a quasi Fermi–Dirac statistics and have an upper bound of mass. The anyon IPP black hole can contain 1 or 2 horizons. This is the first physical VdW-like black hole solution in the global spacetime. Moreover, there exist the Hawking-Page phase transition between the anyon IPP black holes and the pure thermal radiation phase. 相似文献
993.
Sandeep Aashish Abhilash Padhy Sukanta Panda Arun Rana 《The European Physical Journal C - Particles and Fields》2018,78(11):887
We investigate the possibility of inflation with models of antisymmetric tensor field having minimal and nonminimal couplings to gravity. Although the minimal model does not support inflation, the nonminimal models, through the introduction of a nonminimal coupling to gravity, can give rise to stable de-Sitter solutions with a bound on the coupling parameters. The values of field and coupling parameters are sub-planckian. Slow roll analysis is performed and slow-roll parameters are defined which can give the required number of e-folds for sufficient inflation. Stability analysis has been performed for perturbations to antisymmetric field while keeping the metric unperturbed, and it is found that only the sub-horizon modes are free of ghost instability for de-Sitter space. 相似文献
994.
995.
996.
997.
998.
999.
Sergio?Davis Anatoly?B.?Belonoshko Anders?Rosengren Adri?C.?T.?van?Duin B?rje?Johansson 《Central European Journal of Physics》2010,8(5):789-797
The melting point for the tetragonal and cubic phases of zirconia (ZrO2) was computed using Z-method microcanonical molecular dynamics simulations for two different interaction models: the empirical
Lewis-Catlow potential versus the relatively new reactive force field (ReaxFF) model. While both models reproduce the stability of the cubic phase over
the tetragonal phase at high temperatures, ReaxFF also gives approximately the correct melting point, around 2900 K, whereas
the Lewis-Catlow estimate is above 6000 K. 相似文献