全文获取类型
收费全文 | 167篇 |
免费 | 3篇 |
专业分类
化学 | 89篇 |
晶体学 | 32篇 |
力学 | 9篇 |
数学 | 20篇 |
物理学 | 20篇 |
出版年
2023年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 1篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2004年 | 2篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1997年 | 4篇 |
1996年 | 13篇 |
1995年 | 2篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1962年 | 1篇 |
1939年 | 2篇 |
1938年 | 2篇 |
1937年 | 3篇 |
1934年 | 1篇 |
1933年 | 1篇 |
1899年 | 2篇 |
排序方式: 共有170条查询结果,搜索用时 312 毫秒
1.
2.
3.
4.
Janak KE Tanski JM Churchill DG Parkin G 《Journal of the American Chemical Society》2002,124(16):4182-4183
Mo(PMe3)6 reacts with thiophene to give the eta5-thiophene complex (eta5-C4H4S)Mo(PMe3)3 and the eta5-butadiene-thiolate complex (eta5-C4H5S)Mo(PMe3)2(eta2-CH2PMe2), which are the first examples of (i) eta5-thiophene coordination and (ii) C-S cleavage and hydrogenation by a molybdenum compound. Deuterium labeling studies suggest that the hydrogenation of thiophene may involve an alkylidene intermediate, an observation that has ramifications for the mechanisms of hydrodesulfurization. 相似文献
5.
Supercritical fluid chromatography (SFC) with electron-capture detection is described for the sensitive quantification of mefloquine in 0.1-ml blood samples. The method is internally standardized and incorporates partitioning into methyl tert.-butyl ether (MTBE) from aqueous base, back-extraction into dilute aqueous acid and final partitioning into MTBE from aqueous base. SFC conditions include a silica-gel-packed, glass-lined steel column and a mobile phase of 0.15% n-butylamine and 1% methanol in supercritical n-pentane. The method has a detection limit of 7.5 ng/ml in 0.1-ml blood samples and exhibits good linearity and precision. The method compares favorably with a published high-performance liquid chromatographic procedure in the analysis of blood from volunteers who received mefloquine hydrochloride (15 mg as base per kg body weight). 相似文献
6.
7.
Melvyn Rowen Churchill Clifford Bueno David A. Young 《Journal of organometallic chemistry》1981,213(1):139-150
The species FeRu3(CO)13(μ-PPH2)2, synthesized from Ru3(CO)12 and Fe(CO)4(Ph2PPPh2),has been characterized both spectroscopically and via a single-crystal X-ray structural analysis. This complex crystallizes in the centrosymmetric triclinic space group P [No. 2, Ci1] with a 10.066(3), b 12.899(3), c 17.003(4) Å, α 111.89(2), β 91.02(2), γ 102.00(2)°, V 1992.7(9) Å3, Z 2, ?(obsd) 1.79(2) g cm-3 and ?(calcd) 1.82 cm-3. Diffraction data were collected with a Syntex P21 automated four-circle diffractometer and the structure was refined to RF 6.0% and RWF 3.6% for all 5213 reflections (RF 3.8%, RWF 3.6% for those 4140 reflections with |Fo|> 3σ(|Fo|).The metal atoms define a planar triangulated rhombus, with atoms Ru(1) and Ru(2) at the bridgehead, and Fe(1) and Ru(3) at the acute apices. Fe(1) is linked to four terminal carbonyl ligands and is associated with the heteronuclear bonds Fe(1)Ru(1) 2.861(1) Å and Fe(1)Ru(2) 2.868(1) Å. The ruthenium atoms are each bonded to three terminal carbonyl groups. The retheniumruthenium distances are Ru(1)Ru(2) 3.098(1), Ru(1)Ru(3) 3.147(1), and Ru(2)Ru(3) 3.171(1) Å. The structure is completed by Ph2P bridges across the Ru(1)Ru(3) and Ru(2)(ru(3) vectors (<Ru(1)P(1)Ru(3) 84.89(5)° and <Ru(2)P(2)Ru(3) 85.56(6)°). 相似文献
8.
9.
Calculations on [H2Si(C5H4)2]W(Me)H demonstrate that the interconversion between [H2Si(C5H4)2]W(Me)H and the sigma-complex [H2Si(C5H4)2]W(sigma-HMe) is characterized by normal kinetic isotope effects for both reductive coupling and oxidative cleavage; the equilibrium isotope effect, however, is inverse and is the origin of the inverse kinetic isotope effect for the overall reductive elimination of methane. 相似文献
10.