全文获取类型
收费全文 | 69篇 |
免费 | 16篇 |
国内免费 | 20篇 |
专业分类
化学 | 40篇 |
晶体学 | 1篇 |
力学 | 2篇 |
数学 | 10篇 |
物理学 | 52篇 |
出版年
2021年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 11篇 |
2001年 | 7篇 |
2000年 | 11篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1993年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有105条查询结果,搜索用时 15 毫秒
21.
P. MORLIÉRE M. BAZIN L. DUBERTRET R. SANTUS T. SA E. MELO G. HÜPPE J. HAIGLE P. FORLOT A. BERNARD 《Photochemistry and photobiology》1991,53(1):13-19
5-Geranoxypsoralen, commonly called bergamottin, a major furocoumarin contained in bergamot oil, is reported in vitro as a highly photoreactive psoralen. In ethanol, it exhibits quite a high triplet state quantum yield (approximately 0.37). The triplet state is involved in subsequent photochemistry which depends on the initial concentration and on the presence of oxygen. In contrast to most psoralens, absorption and fluorescence data suggest that 5-geranoxypsoralen does not interact with DNA in the dark. No UVA-induced interstrand cross-links in DNA were shown. 相似文献
22.
The TDDFT method is first applied in a series of tetra-nuclear transition metal clusters studies for nonlinear optical properties. The results indicate that the charge transfer inside the metal core [MCu3X4] (M=W, Mo; X=S, O, Cl, Se, Br) makes contribution to the optical nonlinearity. It is possible to enhance the hyperpolarizability by substituting the ligands of the clusters. 相似文献
23.
Yu-Ming ZHENG Hong-Min LIU Ben-Hao SA Zhong-Dao LU Zhong-Qi WANG Xiao-Ze ZHANG 《理论物理通讯》1993,19(1):71-74
A simple Monte Carlo simulation and even a partition method can be used to reproduce quite well the power law behavior between the factorial moment and the charge interval of fragment charge distributions from the multifragmentation of 197Au nucleus bombarding emulsion at~1 GeV/nucleon. This indicates that the above power law seems not to be a unique precursor of the intermittent behavior in nuclear multifragmentations. 相似文献
24.
The charge dispersion of fragments in high energy p+Cu,Kr and Xe reactions are calculated by statistical model and Monte Carlo technique.The corresponding data are reproduced quite well.It is shown that the charge dispersions are all nearly gaussian.The mass dependence of the most probable fragment charge reflects the rest target memory effect. 相似文献
25.
Following the method developed by the authors,recently,the equation of state of hot nuclei(238U in concrete) before break-up was investigated numerically.The isotherms are drawn in the plan of the general pressure P versus volume VRT. They are similar to those of Van der Waals gas.The critical temperature of phase transition should correspond to the isotherm with one turning point only.It turns out that the data of mass yield distribution can be reproduced by many pairs of parameters T and VRT (freeze-out temperature and freeze-out volume) varying in certain range.For each isotherm (each T),the data are always best reproduced by the value of VRT located at the maximum general pressure within two phases coexistence region. 相似文献
26.
LU ZhongDao SA BenHao Masanori Matsuda Junichi Nagata Atsushi Nakamura Osamu Miyamura 《中国物理C(英文版)》2000,24(8):743-747
The Λ multiplicity and Λ/p ratio are studied by hadron transportation-string fragmentation model in relativistic heavy ion collisions. Firstly, the dependence of Λ multiplicity and Λ/p ratio on the system size and the collision centrality is studied. It shows that the Λ and p multiplicities go up as the increase of system size and the increase of collision centrality. However, their ratio keeps almost a constant. The effect of Λ annihilation cross section to Λ multiplicity and Λ/p ratio is also studied. It is found that this effect is weak: Λ multiplicity and Λ/p ratio have a little amount of increase by the decrease of Λ annihilation cross section. Even the cross section is down to zero, Λ/p ratio is only 1.2 in 200A GeV AuAu head on collision. The Λ/p ratio is obtained to be 0.28 in pp collision, lying in the range of experimental data:0.2—0.3. It is also obtained that the ratio in AA collisions is 3—5 times of that in pp collision. 相似文献
27.
28.
The complexes formed between a protein (bovine serum albumin, BSA) and a surfactant (sodium dodecyl sulfate, SDS) were studied as separation carriers in electrokinetic chromatography. Selectivities different from those with either SDS or BSA alone in the background electrolyte (BGE) were obtained. Separation performances were demonstrated to be closely related to the type of complex formed, as predicted by the isotherm curve of SDS on BSA. For each composition of background electrolyte, capacity factors and resolutions were calculated. We compared the results with these complexes to electropherograms using BGE containing either BSA or SDS alone. The separation of a mixture of phenols indicate that some compositions of the BSA-SDS complexes are efficient selectors. 相似文献
29.
An experiment of laser light scattering by a turbulent highly subsonic free jet of air is presented. The originality of the method lies in the fact that no particle seeding is needed. The experimental scattering cross section, which can be interpreted from the three-dimensional spectral density of temperature fluctuations, is compared to the theoretical one obtained by turbulent mixing theories. The scattered field time correlations measured in the heterodyne mode are interpreted by considering the Doppler effect on moving turbulent eddies and compared with theory. The intensity time correlations measured in the homodyne mode are interpreted in terms of local properties of the turbulence. 相似文献
30.
The electrochemical oxidation of N,N-dimethyl-p-phenylene-diamine has been studied by thin layer electrochemistry in neutral or weak acid medium. The two one-electron step oxidations lead to N,N-dimethylquinonediimine which is then hydrolysed to N,N-dimethylquinoneimine. In the 2.75–6 pH range, the kinetic constant of this reaction has been measured. At pH 7, the dimerization of the intermediate radical is the prevailing reaction. By comparing computed theoretical linear potential sweep i-E′ curves to experimental ones, formal potentials were obtained. 相似文献