全文获取类型
收费全文 | 1559篇 |
免费 | 47篇 |
国内免费 | 99篇 |
专业分类
化学 | 453篇 |
晶体学 | 6篇 |
力学 | 222篇 |
综合类 | 5篇 |
数学 | 378篇 |
物理学 | 641篇 |
出版年
2023年 | 15篇 |
2022年 | 23篇 |
2021年 | 20篇 |
2020年 | 31篇 |
2019年 | 27篇 |
2018年 | 28篇 |
2017年 | 32篇 |
2016年 | 41篇 |
2015年 | 36篇 |
2014年 | 94篇 |
2013年 | 118篇 |
2012年 | 68篇 |
2011年 | 105篇 |
2010年 | 64篇 |
2009年 | 111篇 |
2008年 | 104篇 |
2007年 | 92篇 |
2006年 | 79篇 |
2005年 | 71篇 |
2004年 | 55篇 |
2003年 | 43篇 |
2002年 | 56篇 |
2001年 | 40篇 |
2000年 | 40篇 |
1999年 | 39篇 |
1998年 | 39篇 |
1997年 | 34篇 |
1996年 | 24篇 |
1995年 | 16篇 |
1994年 | 17篇 |
1993年 | 20篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 3篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1705条查询结果,搜索用时 734 毫秒
951.
We have discovered an error in the numerical calculations for the extraction of parameters from the nucleon mass “data” presented in Sections 4 and 5 of our paper [M.R. Schindler, D.R. Phillips, Ann. Phys. 324 (2009) 682. Available from: <hep-ph/0808.3643>]. We present the corrected results and discuss the implications. We stress that the material presented in Sections 1–3 of our paper [M.R. Schindler, D.R. Phillips, Ann. Phys. 324 (2009) 682. Available from: <hep-ph/0808.3643>] is unaffected. 相似文献
952.
A. Campargue S. Kassi A. Barbe E. Starikova S.A. Tashkun 《Journal of Molecular Spectroscopy》2009,255(2):75-9935
The absorption spectrum of the 18O3 isotopologue of ozone has been recorded in the 6200-6400 cm−1 region by high sensitivity CW-Cavity Ring Down Spectroscopy. The spectrum is dominated by the 2ν1 + 5ν3 and 2ν1 + 3ν2 + 3ν3 bands at 6270.6 and 6392.2 cm−1, respectively which were treated independently. The rovibrational analysis of the 2ν1 + 5ν3 band has evidenced that the (2 0 5) upper state is perturbed by Coriolis resonance interactions with the (0 1 6), (3 0 4) and (3 5 0) states. A total of 659, 89, 131 and 5 transitions were assigned to the 2ν1 + 5ν3, ν2 + 6ν3, 3ν1 + 4ν3 and 3ν1 + 5ν2 bands, respectively. In the case of the 2ν1 + 3ν2 + 3ν3 band, 344 transitions were assigned. Some of them were found perturbed by a Coriolis interaction of the (2 3 3) state with the (5 2 0) state.Overall, 681 energy levels were derived from the analysis of the 2ν1 + 5ν3 and 2ν1 + 3ν2 + 3ν3 band systems. In both cases, a suitable effective Hamiltonian was elaborated, allowing accounting satisfactorily for the retrieved rovibrational energy levels. In addition, dipole transition moment parameters were determined by a least-squares fit to the measured line intensities. The effective Hamiltonian and transition moment operator parameters were used to generate a list of 1619 transitions given as Supplementary material. 相似文献
953.
E. Starikova M.-R. De Backer-Barilly Vl.G. Tyuterev A.W. Liu 《Journal of Molecular Spectroscopy》2009,255(2):144-9935
The absorption spectrum of 18O3 has been recorded in the 5930-6080 cm−1 region using CW-Cavity Ring Down Spectroscopy. 1888 transitions belonging to five bands have been assigned. Three of them are A-type bands: 2ν2 + 5ν3, ν1 + ν2 + 5ν3 and 5ν1 + ν3, and two bands are of B-type: 2ν1 + ν2 + 4ν3 and 4ν1 + 3ν2. Despite a complex spectral pattern perturbed by many rovibrational resonances, it has been possible to find a suitable effective Hamiltonian model reproducing all the transition wavenumbers (corresponding to 1016 energy levels) with an rms deviation of 9.5 × 10−3 cm−1. A set of 721 line intensities was determined and fitted to derive the effective transition moment parameters. This set of parameters and the experimental energy levels were used to generate a complete line list of 2795 transitions allowing to generate synthetic spectrum in good agreement with the experimental spectrum. 相似文献
954.
We review the recent literature on lattice simulations for few- and many-body systems. We focus on methods that combine the framework of effective field theory with computational lattice methods. Lattice effective field theory is discussed for cold atoms as well as low-energy nucleons with and without pions. A number of different lattice formulations and computational algorithms are considered, and an effort is made to show common themes in studies of cold atoms and low-energy nuclear physics as well as common themes in work by different collaborations. 相似文献
955.
Effective elastic properties of piezoelectric composites containing an infinitely long, radially polarized cylinder embedded in an isotropic non-piezoelectric matrix are theoretically investigated under an external strain field. Analytical solutions of elastic displacement and electric potentials are exactly derived, and the effective elastic responses are formulated in the dilute limit. Meanwhile, a vanishing piezoelectric response mechanism is revealed in the piezoelectric composite containing radially polarized cylinders. Furthermore, it is shown that the effective elastic properties can be enhanced (or reduced) due to the increase of the piezoelectric (or dielectric) constants of the cylinders. 相似文献
956.
详细研究了磁场退火对于具有不同线间距(30~60 nm)和不同线直径(22~46 nm)的Fe48Co52合金纳米线阵列性能的影响.研究表明,退火过程中沿纳米线方向施加3kOe的磁场对于阵列的最佳退火温度和晶体结构以及线直径较小或线间距较大阵列的磁性能均无明显影响.但是对于具有较大线直径或较小线间距的阵列,这种磁场退火处理限制了其易磁化方向的转动并明显提高了其矫顽力与矩形度.认为不同阵列内部有效各向异性场强度之间所存在的差异是导致磁场退火后阵列磁性能出现不同变化的主要原因. 相似文献
957.
通过分子动力学模拟研究了胰岛素与不同尺寸石墨烯的相互作用,并比较了固定的石墨烯与不固定的石墨烯对蛋白质吸附行为及动力学的影响. 通过分析胰岛素蛋白在吸附过程中构象与取向的变化和吸附过程的动力学行为证实了石墨烯对胰岛素蛋白的有效吸附. 通过对蛋白质结构的分析发现蛋白质的三级结构在所有的体系中均有不同程度的破坏,而蛋白质二级结构的稳定性则与体系有关,其中非固定的石墨烯因其具有较大柔性而表现出对蛋白质二级结构的破坏具有一定选择性. 同时还发现石墨烯的尺寸对于胰岛素的吸附动力学过程也有较大影响. 相似文献
958.
959.
分析了实验所得低能γ光子及X射线在Fe和Cu箔透射面产生的次级特征X射线强度测量结果,由此建立起“邻近有效激发模型”。该模型所得结果与实验值在一定范围内相当好地符合。 相似文献
960.
A Monte Carlo Simulation (MCS) has been used to study critical behavior and magnetic properties of a decorated Ising film on a cubic lattice structure. The system consists of two magnetic atoms species A and B with and , where the B sites decorate the bonds between A sites. The dependence of the phase diagram on the axial zero-field splitting parameter, the exchange interactions and the thickness of the film are studied. We found that the system exhibits a double reentrant phenomenon and one or two compensation points. MCS results are compared to those obtained by using the effective field theory (EFT) based on the use of a probability distribution technique. However, MCS predicts the same topology of the phase diagrams as the effective field theory. 相似文献