全文获取类型
收费全文 | 454篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
化学 | 353篇 |
晶体学 | 1篇 |
力学 | 6篇 |
数学 | 18篇 |
物理学 | 86篇 |
出版年
2023年 | 2篇 |
2021年 | 2篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 13篇 |
2013年 | 17篇 |
2012年 | 24篇 |
2011年 | 27篇 |
2010年 | 15篇 |
2009年 | 16篇 |
2008年 | 20篇 |
2007年 | 28篇 |
2006年 | 37篇 |
2005年 | 37篇 |
2004年 | 27篇 |
2003年 | 21篇 |
2002年 | 10篇 |
2001年 | 16篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1988年 | 4篇 |
1987年 | 9篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 10篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1972年 | 2篇 |
1971年 | 6篇 |
1970年 | 4篇 |
1943年 | 1篇 |
排序方式: 共有464条查询结果,搜索用时 15 毫秒
91.
Nanami Hara Shu Fujisawa Mizuki Fujita Mikako Miyazawa Kazuma Ochiai Satoshi Katsuda Tetsuya Fujimoto 《Tetrahedron》2018,74(2):296-302
Kinetic resolution of secondary alcohols by benzoylation using a phosphinite derivative of (1S,2R)-1-amino-2-indanol as the catalyst was investigated. The aminophosphinite catalyst is effective for the kinetic resolution of aryl cycloalkyl carbinols with a small number of examples for organocatalytic kinetic resolution to achieve resolution with s = up to 44. Although the benzoylation of phenylalkanols proceeded with a low selectivity, 1-arylalkanols bearing at least one substituent at the ortho position on the benzene ring or a branched alkyl group on the carbinol carbon were resolved with acceptable selectivity. 相似文献
92.
Cyclopolymerization of a bis-methacrylate monomer derived from trans-cyclohexanediol and 2-methacryloyloxyethyl isocyanate proceeded through 19-membered ring formation. The unusual large ring formation originated from the designed steric regulation by the cyclohexane ring and the hydrogen bonds. The RAFT polymerization employing cumyl dithiobenzoate attained controlled polymerization, which supported the quantitative cyclization. 相似文献
93.
94.
95.
We present the validity of in-line-type differential push-pull methods using segmented gratings with respect to arrangement errors by numerical calculation for the first time. In these differential push-pull methods, the segmented gratings for generating subspots are divided into more than two regions, each with a specific width and a specific phase value, and are ideally arranged on the optical axis. We calculate tracking error signals in these methods with respect to the arrangement errors against the optical axis under parameter conditions of the widths of the segmented regions of the gratings. The obtained results show that the grating with a simpler configuration with two regions reveals good compatibility between DVD-recordable (DVD-R) and DVD-random access memory (DVD-RAM) compared with those with three or four regions, when the arrangement error is less than 10% of the radius of the incident laser beam. 相似文献
96.
Synthesis of medium-sized carbocyclic ketones via the intramolecular B-alkyl Liebeskind-Srogl coupling reaction is described. The sequence of hydroboration of ω-alkenyl thiol ester with 9-BBN and the Liebeskind-Srogl reaction results in the formation of medium-sized carbocyclic ketones with good yield. 相似文献
97.
E. Arakawa N. Ishimatsu N. Kawamura F. Itoh A. Ochiai H. Maruyama O. Shimomura 《Journal of Physics and Chemistry of Solids》2004,65(12):2089-2092
An experimental system for X-ray magnetic diffraction (XMD) under extreme conditions was constructed on the beamline BL39XU at SPring-8. This system aims at studying magnetic properties of ferromagnets through the measurements of magnetic form factors under the conditions of low temperature (5 K), high magnetic field (6 T) and high pressure (10 GPa). This system consists of a superconducting magnet (SCM), a diamond anvil cell (DAC), a two-axis manipulator for the DAC, a five-axis goniometer for the SCM, and an X-ray polarizer with a phase plate. Details of this system are presented. Experimental results on uranium telluride are shown as a performance test with this instrumentation. 相似文献
98.
Finite element schemes based on the method of characteristics are considered for the convection–diffusion equation. Those are proved to be stable, but in a real computation some instability occurs. We reveal the cause of the discrepancy between theory and real computation, and present a remedy to the instability. 相似文献
99.
Ei-Ichiro Ochiai Dean I. Shaffer Dale L. Wampler Paul D. Schettler Jr. 《Transition Metal Chemistry》1986,11(7):241-246
Summary The effects of mixed solvent systems and anions on the rate of reaction of the title compounds were investigated. The results were shown to be best interpreted in terms of ion-pair formation and solvation-desolvation effects, in addition to the factors included in the outer-sphere electron transfer rate theory expounded by Marcus. 相似文献
100.
F. Steglich P. Gegenwart R. Helfrich C. Langhammer P. Hellmann L. Donnevert C. Geibel M. Lang G. Sparn W. Assmus G.R. Stewart A. Ochiai 《Zeitschrift für Physik B Condensed Matter》1996,103(2):235-242
We present the results of specific-heat and resistivity measurements as a function of temperature, magnetic field and hydrostatic pressure on the Kondo lattice CeNi2Ge2, the heavy-fermion superconductors CeCu2Si2 and UBe13 as well as the low-carrier-density system Yb4As3. “Non-Fermi-liquid” effects in the low-temperature normalstate properties of the three former systems are consistent with the existence of a “nearby” quantum critical point, presumably of antiferromagnetic type. Yb4As3, though showing the outward appearance of a Landau-type heavy-fermion metal, behaves very differently, i.e. as an extreme two-fluid system. 相似文献