全文获取类型
收费全文 | 378篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
化学 | 263篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 39篇 |
物理学 | 84篇 |
出版年
2022年 | 7篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 14篇 |
2013年 | 21篇 |
2012年 | 36篇 |
2011年 | 22篇 |
2010年 | 9篇 |
2009年 | 15篇 |
2008年 | 20篇 |
2007年 | 26篇 |
2006年 | 11篇 |
2005年 | 20篇 |
2004年 | 14篇 |
2003年 | 13篇 |
2002年 | 13篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 2篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1933年 | 1篇 |
1910年 | 1篇 |
排序方式: 共有390条查询结果,搜索用时 15 毫秒
91.
Sandeep Ghumaan Biprajit Sarkar Mahendra P. Patil Jan Fiedler Raghavan B. Sunoj Wolfgang Kaim Goutam Kumar Lahiri 《Polyhedron》2007
The complexes (μ3-L1/L2)[Ru(acac)2]3, acac− = 2,4-pentanedionato, L1 = 2,3,8,9,14,15-hexachlorodiquinoxalino[2,3-a:2′,3′-c]phenazine and L2 = 2,3,8,9,14,15- hexamethyldiquinoxalino[2,3-a:2′,3′-c]phenazine, undergo stepwise one-electron oxidation involving a total of three electrons and stepwise one-electron reduction with three (L2) or four electrons (L1). All reversibly accessible states were characterized by UV–Vis–NIR spectroelectrochemistry. Oxidation leads to mixed-valent intermediates {(μ3-L)[Ru(acac)2]3}+ and {(μ3-L)[Ru(acac)2]3}2+ of which the RuIIIRuIIRuII combinations exhibit higher comproportionation constants Kc than the RuIIIRuIIIRuII states – in contrast to a previous report for the unsubstituted parent systems {(μ3-L3)[Ru(acac)2]3}+/2+, L3 = diquinoxalino[2,3-a:2′,3′-c]phenazine. No conspicuous inter-valence charge transfer absorptions were observed for the mixed-valent intermediates in the visible to near-infrared regions. The monocations and monoanions were characterized by EPR spectroscopy, revealing rhombic ruthenium(III) type signals for the former. Electron addition produces ruthenium(II) complexes of the reduced forms of the ligands L, a high resolution EPR spectrum with 14N and 35,37Cl hyperfine coupling and negligible g anisotropy was found for {(μ3-L1)[Ru(acac)2]3}−. DFT calculations of (μ3-L1)[Ru(acac)2]3 confirm several ligand-centered low-lying unoccupied MOs for reduction and several metal-based high-lying occupied MOs for electron withdrawal, resulting in low-energy metal-to-ligand charge transfer (MLCT) transitions. 相似文献
92.
93.
94.
Naskar Nabanita Lahiri Susanta Chaudhuri Punarbasu 《Journal of Radioanalytical and Nuclear Chemistry》2018,316(2):709-715
Journal of Radioanalytical and Nuclear Chemistry - Efficiency calibration by standard materials of known activity is usual protocol for γ-ray spectrometry. In general, 40K activity is measured... 相似文献
95.
Susanta Lahiri Moumita Maiti Kaustab Ghosh 《Journal of Radioanalytical and Nuclear Chemistry》2013,297(3):309-318
111In is amongst the frequently used radionuclides in diagnostic nuclear medicine. Therefore its production and subsequent separation chemistry have been widely investigated since late 40s. 111In is commonly produced in proton or α-particle induced reactions on cadmium or silver targets. However, in recent past, various heavy ion (7Li, 11B, 12C etc.) activation routes have been proposed for its production. In this mini review, we have tried to portray the production routes of 111In and chemical separation methodologies reported so far in the literature in a concise form. A critical analysis presented in this review will be helpful to select suitable nuclear reaction and radiochemical method to produce high purity 111In for applications. 相似文献
96.
An expression is derived for the cross-spectral density matrix, valid in the paraxial region of the far field, generated by a planar blackbody source. With the help of it we determine the spectral degrees of polarization and of cross-polarization of the far field. 相似文献
97.
98.
99.
Somdeb Lahiri 《Annals of Operations Research》2000,97(1-4):45-53
In this paper, we present five categories of results by studying the interrelationships between properties for choice functions.
The first category is about the localization assumption. The second category is about the relative egalitarian solution. The
third category provides an axiomatic characterization of the equal loss solution. The fourth and fifth categories consist
of lexicographic extensions of the equal loss and relative egalitarian solutions respectively.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
100.