全文获取类型
收费全文 | 5356篇 |
免费 | 171篇 |
国内免费 | 19篇 |
专业分类
化学 | 3228篇 |
晶体学 | 31篇 |
力学 | 76篇 |
数学 | 751篇 |
物理学 | 1460篇 |
出版年
2022年 | 53篇 |
2021年 | 79篇 |
2020年 | 82篇 |
2019年 | 98篇 |
2018年 | 74篇 |
2017年 | 80篇 |
2016年 | 207篇 |
2015年 | 189篇 |
2014年 | 245篇 |
2013年 | 431篇 |
2012年 | 259篇 |
2011年 | 289篇 |
2010年 | 205篇 |
2009年 | 170篇 |
2008年 | 224篇 |
2007年 | 186篇 |
2006年 | 220篇 |
2005年 | 122篇 |
2004年 | 123篇 |
2003年 | 96篇 |
2002年 | 112篇 |
2001年 | 64篇 |
2000年 | 81篇 |
1999年 | 58篇 |
1998年 | 69篇 |
1997年 | 56篇 |
1996年 | 63篇 |
1995年 | 58篇 |
1994年 | 45篇 |
1993年 | 59篇 |
1992年 | 43篇 |
1991年 | 47篇 |
1990年 | 43篇 |
1989年 | 35篇 |
1988年 | 57篇 |
1987年 | 56篇 |
1986年 | 42篇 |
1985年 | 66篇 |
1984年 | 60篇 |
1983年 | 44篇 |
1982年 | 36篇 |
1981年 | 38篇 |
1980年 | 49篇 |
1979年 | 44篇 |
1978年 | 43篇 |
1977年 | 55篇 |
1976年 | 52篇 |
1975年 | 49篇 |
1974年 | 59篇 |
1973年 | 42篇 |
排序方式: 共有5546条查询结果,搜索用时 15 毫秒
1.
2.
A protocol to correct for intra‐ and interspecific variation in tail hair growth to align isotope signatures of segmentally cut tail hair to a common time line 下载免费PDF全文
3.
4.
5.
Palladium and molybdenum polycrystalline layers (clusters) have been deposited in a stainless steel UHV system onto a layer of alumina (Al2O3). This layer has been prepared by high temperature oxidation of an aluminium layer. The interaction of this system with nitrogen has been investigated at room temperature by an FEM technique. Under these conditions nitrogen spillover from molybdenum to palladium has been observed. 相似文献
6.
V. Balek T. Mitsuhashi I.M. Bountseva H. Haneda Z. Malek J. Šubrt 《Journal of Sol-Gel Science and Technology》2003,26(1-3):185-189
The diffusion structural analysis (DSA) was used to characterize microstructure changes of hydrous titania gel films under in situ conditions of heating. TG and DTA were used in order to elucidate the processes controlling the formation of anatase film during heating of hydrous titania gel film. The annealing of porosity and near surface structure defects of the dehydrated titania films was indicated by DSA in the temperature range 255–700°C as the decrease of radon release rate. It was demonstrated that the annealing was enhanced on heating in oxygen in comparison with heating in argon. The DSA experimental results were compared with model curves describing the radon diffusion mobility and the annealing of radon diffusion paths. 相似文献
7.
V. Petržílka 《Czechoslovak Journal of Physics》1997,47(2):183-196
Test particle motion and acceleration has been explored in strong radio frequency (RF) fields, for which quasilinear ponderomotive force approximation is not valid. By nonlinear acceleration in spatially varying wave amplitude of RF travelling wave, electrons may be accelerated to time averaged velocities significantly larger than the RF wave phase velocity, and than the boundary plasma thermal velocity, in RF fields of several Volts per centimeter at wave frequency of 7 MHz. It is also demonstrated that even weak spatial gradients, much weaker than those expected in experiments, of the RF wave field amplitude, have significant consequences for the particle motion. Estimates are presented of the total energy transferred from the near antenna RF field to the plasma due to the nonlinear electron acceleration effects. 相似文献
8.
Pavla Fialová Inmaculada Robina Petr Sedmera Lucie Petrásková-Hušáková 《Tetrahedron letters》2005,46(50):8715-8718
Glycosyl azides are new efficient donors for glycosidases. Their high water solubility facilitates transglycosylations with comparable or better yields than common O-glycosides. The azido group totally changes the β-GalNAc-ase/β-GlcNAc-ase ratio in β-N-acetylhexosaminidases (from the usual 0.3-1.0 to <0.01), contrary to all known aglycons. 相似文献
9.
Peter Šimon 《Journal of Thermal Analysis and Calorimetry》2006,83(3):521-522
This
issue of Journal of Thermal Analysis and Calorimetry contains selected papers
based on presentations in the field of thermal characteristics of advanced
polymer systems presented at the 8th International
Symposium on Polymers for Advanced Technologies (PAT 2005) held in Budapest,
September 2005.
Guest Editors 相似文献
10.
J. Petrů 《Zeitschrift für Physik B Condensed Matter》1993,91(3):351-356
TheN-fold degenerate Anderson single impurity model in the infiniteU limit is treated by means of the irreducible Green functions method. In this approach a derivation of an exact Dyson equation and an exact self-energy operator is possible. The necessity of introducing auxiliary fields, such as slave-bosons is avoided. 相似文献