全文获取类型
收费全文 | 235篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
化学 | 194篇 |
晶体学 | 2篇 |
数学 | 14篇 |
物理学 | 33篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 18篇 |
2012年 | 13篇 |
2011年 | 15篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 21篇 |
2007年 | 23篇 |
2006年 | 13篇 |
2005年 | 15篇 |
2004年 | 14篇 |
2003年 | 7篇 |
2002年 | 10篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
排序方式: 共有243条查询结果,搜索用时 250 毫秒
71.
72.
Kazutoshi Tanabe 《Chemical physics》1979,38(1):125-129
Line widths of isotropic Raman spectra of the ν1 (a1) CH or CD stretching bands of acetonitrile CH3CN and CD3CN were measured in a number of solvents. The vibrational dephasing theory, modified for use in binary mixtures, predicts quantitatively the solvent dependence of the Raman line widths. 相似文献
73.
Shindo K Osawa A Nakamura R Kagiyama Y Sakuda S Shizuri Y Furukawa K Misawa N 《Journal of the American Chemical Society》2004,126(46):15042-15043
The comprehensive bioconversion of aromatic compounds with a benzene ring to a picolinic acid was achieved with a recombinant Escherichia coli strain that expressed the six genes involved in biphenyl catabolism, these being the bphA1(2072)A2A3A4 genes encoding the evolved biphenyl dioxygenase, the bphB gene encoding dihydrodiol dehydrogenase, and the bphC gene encoding catechol 2,3-dioxygenase. 相似文献
74.
Aoki M Kaneko M Izumi S Ukai K Iwasawa N 《Chemical communications (Cambridge, England)》2004,(22):2568-2569
Novel bidentate amidines were designed and synthesized as easily available electron-donating N-ligands for Ni0-mediated coupling of carbon dioxide with alkynes or allenes, and high regioselectivity was achieved even for the carboxylation of aryl substituted internal alkynes. 相似文献
75.
76.
Eguchi T Kobayashi K Uekusa H Ohashi Y Mizoue K Matsushima Y Kakinuma K 《Organic letters》2002,4(20):3383-3386
The absolute stereochemistry of FD-891, a novel cytotoxic 18-membered macrolactone antibiotic, was determined by a synthetic approach as well as X-ray diffraction of degradative derivatives. The absolute configuration of FD-891 turned out to be as shown above. The stable conformer of FD-891 was also discussed with respect to biological activity by comparison with the structurally related concanamycin A on the bases of molecular mechanics calculations. [structure: see text] 相似文献
77.
We study a combination of the refracted and reflected Lévy processes. Given a spectrally negative Lévy process and two boundaries, it is reflected at the lower boundary while, whenever it is above the upper boundary, a linear drift at a constant rate is subtracted from the increments of the process. Using the scale functions, we compute the resolvent measure, the Laplace transform of the occupation times as well as other fluctuation identities that will be useful in applied probability including insurance, queues, and inventory management. 相似文献
78.
Keiki Kishikawa Wongsiri Sankhavasi Makoto Yamamoto Shigeo Kohmoto Kazutoshi Yamada 《合成通讯》2013,43(15):2339-2347
A convenient synthesis of natural (±)-blastmycino-lactol from the aldol addition reaction of n-pentanoylurea and (±)-2-benzyloxypropionaldehyde is described. 相似文献
79.
Kei Toda Haruka KuwaharaHidetaka Kajiwara Kazutoshi HirotaShin-Ichi Ohira 《Analytica chimica acta》2014
The highly odorous compound methanethiol, CH3SH, is commonly produced in biodegradation of biomass and industrial processes, and is classed as 2000 times more odorous than NH3. However, there is no simple analytical method for detecting low parts-per-billion in volume ratio (ppbv) levels of CH3SH. In this study, a micro gas analysis system (μGAS) was developed for continuous or near real time measurement of CH3SH at ppbv levels. In addition to a commercial fluorescence detector, a miniature high sensitivity fluorescence detector was developed using a novel micro-photomultiplier tube device. CH3SH was collected by absorption into an alkaline solution in a honeycomb-patterned microchannel scrubber and then mixed with the fluorescent reagent, 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F). Gaseous CH3SH was measured without serious interference from other sulfur compounds or amines. The limits of detection were 0.2 ppbv with the commercial detector and 0.3 ppbv with the miniature detector. CH3SH produced from a pulping process was monitored with the μGAS system and the data agreed well with those obtained by collection with a silica gel tube followed by thermal desorption–gas chromatography–mass spectrometry. The portable system with the miniature fluorescence detector was used to monitor CH3SH levels in near-real time in a stockyard and it was shown that the major odor component, CH3SH, presented and its concentration varied dynamically with time. 相似文献
80.
Burzurí E Luis F Barbara B Ballou R Ressouche E Montero O Campo J Maegawa S 《Physical review letters》2011,107(9):097203
We show that a crystal of mesoscopic Fe(8) single-molecule magnets is an experimental realization of the quantum Ising model in a transverse field, with dipolar interactions. Quantum annealing has enabled us to explore the quantum and classical phase transitions between the paramagnetic and ferromagnetic phases, at thermodynamical equilibrium. The phase diagram and critical exponents that we obtain agree with expectations for the mean-field universality class. 相似文献