全文获取类型
收费全文 | 496篇 |
免费 | 27篇 |
国内免费 | 1篇 |
专业分类
化学 | 391篇 |
晶体学 | 1篇 |
力学 | 6篇 |
数学 | 32篇 |
物理学 | 94篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 11篇 |
2020年 | 15篇 |
2019年 | 12篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 20篇 |
2015年 | 9篇 |
2014年 | 12篇 |
2013年 | 16篇 |
2012年 | 37篇 |
2011年 | 30篇 |
2010年 | 17篇 |
2009年 | 17篇 |
2008年 | 26篇 |
2007年 | 26篇 |
2006年 | 21篇 |
2005年 | 22篇 |
2004年 | 25篇 |
2003年 | 23篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 9篇 |
1999年 | 7篇 |
1997年 | 4篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1963年 | 2篇 |
1961年 | 2篇 |
1959年 | 2篇 |
排序方式: 共有524条查询结果,搜索用时 17 毫秒
1.
The chemiluminescence (CL) intensities of various indole derivatives substituted with a glyoxylyl group at the 3-position and a hydroxyl group at the 5-position of the indole ring were compared upon the addition of H2O2 in alkaline media. The CL intensities of 3-indoleglyoxylyl chloride, 3-indoleglyoxylic acid, 5-hydroxyindole and 5-benzyloxyindole in CH3CN were 5.9-, 48-, 5.9- and 3.3-fold stronger than that of 3-methylindole. A lasting CL of 3-indoleglyoxylyl chloride was found. Under appropriate conditions, the CL emission reached a maximum within 10 min after the addition of H2O2 in the presence of NaOH, and the intensity was retained for 25 min. One of the final products via the CL reaction of 3-indoleglyoxylyl chloride was indole-3-carboxylic acid. 3-Indoleglyoxylyl chloride emitted light by decompositions via both dioxetane and dioxetanedione. An enhancement effect of beta-cyclodextrin and bovine serum albumin on the CL of 3-indoleglyoxylyl chloride was also found. 相似文献
2.
It is theoretically predicted that the Nernst coefficient is strongly suppressed and the thermal conductance is quantized in the quantum Hall regime of the two-dimensional electron gas. The Nernst effect is the induction of a thermomagnetic electromotive force in the y-direction under a temperature bias in the x-direction and a magnetic field in the z-direction. The quantum nature of the Nernst effect is analyzed with the use of a circulating edge current and is demonstrated numerically. The present system is a physical realization of the non-equilibrium steady state. 相似文献
3.
4.
Koichi Mikami Yukinori Yusa Manabu Hatano Kazuki Wakabayashi Kohsuke Aikawa 《Tetrahedron》2004,60(20):4475-4480
A tropos rhodium(I) complex having skewphos ligand is shown to be a highly enantioselective catalyst for asymmetric ene-type carbocyclization of 1,6-enynes with tri-substituted olefins to control quaternary stereogenic centers or spiro-rings. 相似文献
5.
6.
V. P. Ladygin T. Uesaka T. Saito M. Hatano A. Yu. Isupov H. Kato N. B. Ladygina Y. Maeda A. I. Malakhov J. Nishikawa T. Ohnishi H. Okamura S. G. Reznikov H. Sakai N. Sakamoto S. Sakoda Y. Satou K. Sekiguchi K. Suda A. Tamii N. Uchigashima K. Yako 《Physics of Atomic Nuclei》2006,69(8):1271-1278
RIKEN Accelerator Research Facility data on the tensor analyzing power T 20 of the dd → 3Hen and dd → 3Hp reactions at zero angle for deuteron kinetic energies of 140, 200, and 270 MeV are reported. The observed positive sign of T 20 clearly demonstrates the sensitivity to the D/S-wave ratio in the 3He and 3H wave functions in the energy range of the experiment. Data on T 20 for the 3Hen channel are in agreement with those for the 3Hp channel within the experimental errors. 相似文献
7.
Atsushi Ikeda Masaru Kawaguchi Yoshio Suzuki Tsukasa Hatano Munenori Numata Seiji Shinkai Akio Ohta Makoto Ohta 《Journal of inclusion phenomena and macrocyclic chemistry》2000,38(1-4):163-170
The calixarene-fullerene interaction,which causes only a slight change in the absorptionspectra, has been substantiated by calorimetricmeasurements: the H° values arecomparable with those obtained from the associationconstants estimated by a spectroscopic method. Furthermore, we determined the association constantbetween homooxacalix[3]arene and [60]fullerenederivatives with a porphyrin moiety by fluorescencespectra. 相似文献
8.
9.
10.
Tadamasa Shida Yasufumi Takahashi Hiroyuki Hatano Masashi Imamura 《Chemical physics letters》1975,33(3):491-494
Radical-anions of iodine, bromine, and monoiodochloride are produced in γ-irradiated amorphous solids at 77 K, and their electronic and ESR spectra measured. On limited warming of the irradiated solution dimerization by the reaction I2? + I2 → I4? occurs to produce the same species as reported by Fornier de Violet et al. The electronic structure of the dimeric anion is discussed in comparison with the monomeric anion. 相似文献