全文获取类型
收费全文 | 700篇 |
免费 | 21篇 |
国内免费 | 7篇 |
专业分类
化学 | 584篇 |
晶体学 | 4篇 |
力学 | 3篇 |
数学 | 27篇 |
物理学 | 110篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2020年 | 13篇 |
2019年 | 9篇 |
2017年 | 4篇 |
2016年 | 13篇 |
2015年 | 14篇 |
2014年 | 20篇 |
2013年 | 50篇 |
2012年 | 33篇 |
2011年 | 40篇 |
2010年 | 22篇 |
2009年 | 22篇 |
2008年 | 34篇 |
2007年 | 32篇 |
2006年 | 48篇 |
2005年 | 26篇 |
2004年 | 34篇 |
2003年 | 20篇 |
2002年 | 20篇 |
2001年 | 24篇 |
2000年 | 25篇 |
1999年 | 12篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 5篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 13篇 |
1987年 | 12篇 |
1986年 | 4篇 |
1985年 | 13篇 |
1984年 | 12篇 |
1983年 | 6篇 |
1982年 | 13篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1968年 | 3篇 |
1966年 | 4篇 |
排序方式: 共有728条查询结果,搜索用时 380 毫秒
91.
92.
T Tatsuoka K Suzuki K Imao F Satoh T Ishihara I Hirotsu T Kihara M Hatta Y Horikawa K Sumoto 《Chemical & pharmaceutical bulletin》1992,40(9):2382-2386
A new series of 4-(1,4-benzoquinon-2-yl)-4-phenylbutanamides (2) were synthesized for evaluation of their pharmacological activities. All these compounds synthesized showed significant antilipidperoxidation (ALP) activities with brain homogenate in rats and some of them possessed a protective effect against hypobaric hypoxia in mice. Especially, a thiomorpholine derivative (2l, SUN-4757) showed a wide efficacy spectrum to a variety of experimental screening assays designed for cerebral protective agents, and it had a high LD50 value. 相似文献
93.
Tadashi Miyasaka Hiromichi Tanaka Kazue Satoh Mie Imahashi Kentaro Yamaguchi Yoichi Iitaka 《Journal of heterocyclic chemistry》1987,24(3):873-875
A highly efficient intramolecular nitrene insertion was observed upon irradiation of 6-azidouridine derivatives. The N6,2′-cyclo structure of the product was determined unequivocally by X-ray crystallography. 相似文献
94.
Ryosuke Sakae Dr. Koji Hirano Prof. Dr. Tetsuya Satoh Prof. Dr. Masahiro Miura 《Angewandte Chemie (International ed. in English)》2015,54(2):613-617
A copper‐catalyzed aminoboration of bicyclic alkenes, including oxa‐ and azabenzonorbornadienes, has been developed. With this method, amine and boron moieties are simultaneously introduced at an olefin with exo selectivity. Subsequent stereospecific transformations of the boryl group can provide oxygen‐ and nitrogen‐rich cyclic molecules with motifs that may be found in natural products or pharmaceutically active compounds. Moreover, a catalytic asymmetric variant of this transformation was realized by using a copper complex with a chiral bisphosphine ligand, namely (R,R)‐Ph‐BPE. 相似文献
95.
M. Sugawara E. Tamura Y. Satoh Y. Komatsu M. Tago H. Beer 《Heat and Mass Transfer》2007,43(10):1009-1018
Visual observations reveal a complicated flow in the liquid melt and a melting front configuration resulting from horizontal
ice plate melting from above into a 20 wt% calcium chloride aqueous solution. The initial temperature of the ice plate and
the mixture are both −5°C. Small scale “mountain and valley” structures (∼1 mm) appear on the flat melting front just after
melting begins, which have been called “sharkskin”. Innumerable upward and downward flows appear near the sharkskin and are controlled by its “mountain and valley” structure. These typical flows will considerably promote the melting of the
ice plate to be 30% larger as compared to the numerically predicted results assuming a flat melting front (i.e., without the
sharkskin), and also by three times larger compared with the results for melting from below. 相似文献
96.
Hitoshi MomochiTakafumi Noguchi Toshifumi MiyagawaNaoki Ogawa Makoto TadokoroTsuyoshi Satoh 《Tetrahedron letters》2011,52(23):3016-3019
The reaction of lithium α-sulfinyl carbanion of enantiopure dichloromethyl p-tolyl sulfoxide with α,β-unsaturated carbonyl compounds gave optically active 1-chlorocyclopropyl p-tolyl sulfoxides having a carbonyl group with high asymmetric induction from the sulfur chiral center. Reduction of the carbonyl group followed by treatment with Grignard reagent, the 1-chlorocyclopropyl p-tolyl sulfoxides resulted in the formation of enantiopure allenic alcohols via the Doering-LaFlamme-type rearrangement of enantiopure cyclopropylmagnesium carbenoid intermediates. This is the first example for the asymmetric synthesis of allenes by the Doering-LaFlamme allene synthesis. 相似文献
97.
A room temperature copper-catalyzed annulative amination of ortho-alkynylphenols with electrophilic amination reagents, O-acylated hydroxylamines, proceeds efficiently to provide the corresponding 3-aminobenzofurans of biological and pharmaceutical interest. 相似文献
98.
The direct dehydrogenative C-N coupling of azoles or polyfluoroarenes with N-H sulfoximines proceeds effectively in the presence of a copper catalyst at room temperature under air to afford the corresponding N-arylsulfoximines in good to high yields. 相似文献
99.
Akira Satoh 《Molecular physics》2013,111(7):656-670
We have investigated the behaviour of a suspension of magnetic rod-like hematite particles in a simple shear flow with the addition of an applied magnetic field. A significant feature of the present hematite particle suspension is the fact that the magnetic moment of the hematite particle lies normal to the particle-axis direction. From simulations, we have attempted to clarify the dependence of the negative magneto-rheological effect on the particle aggregation and orientational distribution of particles. The present Brownian dynamics method has a significant advantage in that it takes into account the spin rotational Brownian motion about the particle axis in addition to the ordinary translational and rotational Brownian motion. The net viscosity is decomposed into three components and discussed at a deeper level and in detail: these three viscosity components arise from (1) the torque due to the magnetic particle–field interaction, (2) the torque and (3) the force due to the interaction between particles. It is found that a slight change in the orientational distribution has a significant influence on the negative magneto-rheological effect. In a relatively dense suspension, the viscosity components arising from an applied magnetic field and the interaction between particles come to change rapidly for a certain strength of the magnetic particle–particle interaction, which is due to the onset of the formation of raft-like clusters. 相似文献
100.