全文获取类型
收费全文 | 1591篇 |
免费 | 63篇 |
国内免费 | 6篇 |
专业分类
化学 | 1240篇 |
晶体学 | 20篇 |
力学 | 16篇 |
数学 | 126篇 |
物理学 | 258篇 |
出版年
2023年 | 9篇 |
2022年 | 12篇 |
2021年 | 15篇 |
2020年 | 31篇 |
2019年 | 30篇 |
2018年 | 28篇 |
2017年 | 10篇 |
2016年 | 25篇 |
2015年 | 44篇 |
2014年 | 35篇 |
2013年 | 83篇 |
2012年 | 94篇 |
2011年 | 119篇 |
2010年 | 62篇 |
2009年 | 71篇 |
2008年 | 136篇 |
2007年 | 120篇 |
2006年 | 104篇 |
2005年 | 75篇 |
2004年 | 82篇 |
2003年 | 74篇 |
2002年 | 71篇 |
2001年 | 32篇 |
2000年 | 33篇 |
1999年 | 11篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 13篇 |
1995年 | 7篇 |
1993年 | 10篇 |
1992年 | 19篇 |
1991年 | 16篇 |
1990年 | 6篇 |
1989年 | 12篇 |
1988年 | 11篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 13篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 11篇 |
1979年 | 5篇 |
1978年 | 14篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 8篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1970年 | 4篇 |
排序方式: 共有1660条查询结果,搜索用时 15 毫秒
101.
Masao Hirano Shigetaka Yakabe James H. Clark Hiroyuki Kudo Takashi Morimoto 《合成通讯》2013,43(10):1875-1886
A wide variety of sulphides can be readily converted to the corresponding sulphoxides in good to excellent yields by treatment with a combination of sodium chlorite, (salen)manganese(III) complex, and chromatographic alumina in dichloromethane under mild and neutral conditions. 相似文献
102.
We prove that every k-connected graph (k ≥ 5) has an even cycle C such that G-V (C) is still (k-4)-connected. The connectivity bound is best possible. 相似文献
103.
Tae-Ho Kim Masakazu Saito Masaya Matsuoka Shinya Tsukada Kiyohisa Wada Masakazu Anpo 《Research on Chemical Intermediates》2010,36(5):453-461
It was found that the photoelectrochemical performance and photocatalytic activity of rod-type TiO2 electrodes were affected by various post-calcination treatments, for example, calcination in NH3 or under vacuum. Post-calcination treatment in NH3 at 773 K was particularly effective in increasing the photoelectrochemical performance and photocatalytic activity of rod-type
TiO2 electrodes. A unique photoelectrochemical circuit was constructed by connecting a rod-type TiO2 electrode to a Pt electrode through a silicon solar cell in which the negative bias was applied on the rod-type TiO2 electrode. It was found that the photoelectrochemical circuit can effectively oxidize ethanethiol in water into CO2. 相似文献
104.
105.
Masahiro Yamashita Daisuke Kawakami Satoshi Matsunaga Yoshio Nakayama Mari Sasaki Shinya Takaishi Fumiyasu Iwahori Hitoshi Miyasaka Ken‐ichi Sugiura Yoshiki Wada Hiroshi Miyamae Hiroyuki Matsuzaki Hiroshi Okamoto Hisaaki Tanaka Kazuhiro Marumoto Shin‐ichi Kuroda 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2004,116(36):4867-4871
106.
107.
108.
An evaluation of the feasibility of liquid chromatography-mass spectrometry (LC-MS) with atmospheric pressure ionization was made for quantitation of four diarrhetic shellfish poisoning toxins, okadaic acid, dinophysistoxin-1, pectenotoxin-6 and yessotoxin in scallops. When LC-MS was applied to the analysis of scallop extracts, large signal suppressions were observed due to coeluting substances from the column. To compensate for these matrix signal suppressions, the standard addition method was applied. First, the sample was analyzed and then the sample involving the addition of calibration standards is analyzed. Although this method requires two LC-MS runs per analysis, effective correction of quantitative errors was found. 相似文献
109.
Jensen P Odaka TE Kraemer WP Hirano T Bunker PR 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(4):763-794
We have developed a computational procedure, based on the variational method, for the calculation of the rovibronic energies of a triatomic molecule in an electronic state that become degenerate at the linear nuclear configuration. In such an electronic state the coupling caused by the electronic orbital angular momentum is very significant and it is called the Renner effect. We include it, and the effect of spin-orbit coupling, in our program. We have developed the procedure to the point where spectral line intensities can be calculated so that absorption and emission spectra can be simulated. In order to gain insight into the nature of the eigenfunctions, we have introduced and calculated the overall bending probability density function f(p) of the states. By projecting the eigenfunctions onto the Born-Oppenheimer basis, we have determined the probability density functions f+(rho) and f-(rho) associated with the individual Born-Oppenheimer states phi(-)elec and phi(+)elec. At a given temperature the Boltzmann averaged value of the f(p) over all the eigenstates gives the bending probability distribution function F(rho), and this can be related to the result of a Coulomb Explosion Imaging (CEI) experiment. We review our work and apply it to the molecules CH2+, MgNC and NH2, all of which are of astrophysical interest. 相似文献
110.