全文获取类型
收费全文 | 832篇 |
免费 | 13篇 |
国内免费 | 2篇 |
专业分类
化学 | 682篇 |
晶体学 | 12篇 |
力学 | 7篇 |
数学 | 24篇 |
物理学 | 122篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 17篇 |
2019年 | 13篇 |
2018年 | 9篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 19篇 |
2013年 | 28篇 |
2012年 | 38篇 |
2011年 | 63篇 |
2010年 | 31篇 |
2009年 | 29篇 |
2008年 | 43篇 |
2007年 | 53篇 |
2006年 | 51篇 |
2005年 | 48篇 |
2004年 | 45篇 |
2003年 | 50篇 |
2002年 | 44篇 |
2001年 | 26篇 |
2000年 | 24篇 |
1999年 | 17篇 |
1998年 | 7篇 |
1997年 | 8篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 15篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1976年 | 5篇 |
1975年 | 11篇 |
1973年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有847条查询结果,搜索用时 95 毫秒
41.
42.
Taku Hirama Takayuki Umemura Noriyuki Kogure Mariko Kitajima Hiromitsu Takayama 《Tetrahedron letters》2017,58(3):223-226
A new procedure for the asymmetric total synthesis of lythraceous alkaloids with a 4-arylquinolizidine skeleton was developed, which involved an organocatalyzed asymmetric intramolecular aza-Michael addition. 相似文献
43.
Haizhou Wu Noriyuki Watanabe Yohichi Gohshi Ryuji Kotama 《Fresenius' Journal of Analytical Chemistry》1999,363(4):424-426
A mixture of 2-hydroxy-2-methylpropanoic acid (HIBA) and glycolic acid, with 1-octanesulfonate (OS) as hydrophobic ion proved
to be successful for the separation of rare-earth elements (REE). If the ratio of HIBA and glycolic acid is suitably adjusted,
it is possible to separate Y from Dy. The resolution of Y and Dy was further improved by controlling the concentration of
HIBA and glycolic acid. The technique was applied successfully to the separation and analysis of highly pure Y2O3 and Dy2O3.
Received: 30 June 1998 / Revised: 3 September 1998 / Accepted: 15 September 1998 相似文献
44.
45.
Mariko Kitajima Tomomi Yanagisawa Mari Tsukahara Yasuka Yamaguchi Noriyuki Kogure Ruri Kikura-Hanajiri Yukihiro Goda Osamu Iida Yasushi Sugimura Nobuo Kawahara Hiromitsu Takayama 《Tetrahedron》2018,74(4):441-452
Three new biphenyl ether quinolizidine lactone alkaloids (1–3) and 13 new biphenyl quinolizidine lactone alkaloids (4–16) were isolated from Heimia salicifolia (Lythraceae) together with seven known alkaloids. Their structures were determined by spectroscopic analyses and chemical conversions. 相似文献
46.
Kurahashi T Miyazaki A Suwan S Isobe M 《Journal of the American Chemical Society》2001,123(38):9268-9278
The ESI (electrospray ionization)-Q-TOF (tandem quadrupole/orthogonal-acceleration time-of-flight) mass spectrometer combined with the nano-HPLC (high performance liquid chromatography) system was utilized to pinpoint the Cu-binding site in Cu,Zn-SOD (superoxide dismutase) protein. Cu,Zn-SOD was treated with hydrogen peroxide, intended to specifically oxidize histidine residues coordinated to the copper ion as a mass spectrometric probe. The oxidized Cu,Zn-SOD was then fragmented with the successive treatment of endoproteinase Asp-N and DTT (dithiothreitol). Separation of the peptide mixture with the nano-HPLC and the on-line ESI-Q-TOF MS analysis revealed that only two peptide fragments were oxidized to a significant extent. Further analyses of oxidized peptide fragments with LC-ESI-Q-TOF-MS/MS disclosed that three out of four Cu-coordinated histidine residues were specifically oxidized by action of a redox-active copper ion and hydrogen peroxide, demonstrating the copper-catalyzed oxidation of amino acid ligands could be a versatile tool for the mass spectrometric determination of the copper-binding site. In addition, proline and valine residues in the proximity of the Cu ion were found to be oxidized upon H(2)O(2) treatment. 相似文献
47.
48.
49.
Junji Kido Yasuyuki Imamura Noriyuki Kuramoto Katsutoshi Nagai 《Journal of colloid and interface science》1992,150(2)
Interactions between poly(N-substituted acrylamide)s and surfactants, such as sodium dodecyl sulfate (SDoS) and sodium decyl sulfate (SDeS), in aqueous solutions were investigated using a solvatochromic probe. The polymers used were poly(N,N-dimethylacrylamide) (PDMA), poly(N-isopropylacrylamide) (PIPA), poly(N-acryloylpyrrolidine) (PAPR), and poly(vinylpyrrolidone) (PVPy) for comparison. They were labeled with pyridinium dicyanomethylide chromophore as a solvatochromic probe, and the changes in the microenvironment polarity of the polymer upon association with surfactant micelles were investigated by monitoring the λmax in the absorption spectra of the probe molecule. It was found that the Gibbs free energy of micelle stabilization by polymer complexation for SDoS is 7.6, 4.1, and 2.2 kJ mol−1, and for SDeS 5.1, 2.9, and 0.8 kJ mol−1 with PIPA, PAPR, and PDMA, respectively. These results indicate that the complexation between polymer and surfactant is influenced not only by the alkyl-chain length of the surfactant, but also by the polymer side groups. 相似文献
50.
Noriyuki Otsubo 《Journal of Number Theory》2011,131(4):648-660
We compare two calculations due to Bloch and the author of the regulator of an elliptic curve with complex multiplication which is a quotient of a Fermat curve, and express the special value of its L-function at s=0 in terms of special values of generalized hypergeometric functions. 相似文献