全文获取类型
收费全文 | 603篇 |
免费 | 16篇 |
国内免费 | 3篇 |
专业分类
化学 | 472篇 |
晶体学 | 1篇 |
力学 | 2篇 |
数学 | 20篇 |
物理学 | 127篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 3篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 20篇 |
2012年 | 26篇 |
2011年 | 27篇 |
2010年 | 20篇 |
2009年 | 16篇 |
2008年 | 39篇 |
2007年 | 44篇 |
2006年 | 21篇 |
2005年 | 30篇 |
2004年 | 31篇 |
2003年 | 29篇 |
2002年 | 31篇 |
2001年 | 21篇 |
2000年 | 14篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 19篇 |
1996年 | 15篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 9篇 |
1983年 | 3篇 |
1982年 | 11篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1971年 | 4篇 |
排序方式: 共有622条查询结果,搜索用时 46 毫秒
1.
2.
3.
Dr. Tatsuya Takimoto Prof. Hideaki Sasaki Prof. Hirohito Tsue Dr. Hiroki Takahashi Prof. Alexander D. MacKerell Jr. Ayumi Nakamura Katsuya Nakano Eori Okazaki Tatsuki Betsuyaku Ryosuke Tachibana Dr. Kazuhito Hioki Dr. Ozge Yoluk Dr. Sunhwan Jo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(5):1648-1654
A simple approach to the synthesis of heterocyclophane consisting of two 4,4’-bithiazoles has been developed in mild conditions. The heterocyclophane with two short chains was conveniently prepared by Hantzsch thiazoles synthesis using the reaction of 3-tert-butoxycarbonyl-3-azapentanethiocarboxamide with 1,4-dibromobutane-2,3-dione in methanol under reflux for only 15 min. Amino groups at the linkers of this heterocyclophane can be functionalized to give acylated and carbamate derivatives. Their properties as protein kinase inhibitors were investigated, and one of the heterocyclophanes exhibited specific anti-activity for c-mesenchymal epithelial transition factor (IC50=603 nm ), among seven types of protein kinases investigated. The computational site identification by ligand competitive saturation method was used to determine why the one heterocyclophane exhibited strong anti-activity for c-mesenchymal epithelial transition factor. 相似文献
4.
5.
A note on a forcing related to the S‐space problem in the extension with a coherent Suslin tree 下载免费PDF全文
Teruyuki Yorioka 《Mathematical Logic Quarterly》2015,61(3):169-178
One of the main problems about is that whether a coherent Suslin tree forces that there are no S‐spaces under . We analyze a forcing notion related to this problem, and show that under , S forces that every topology on ω1 generated by a basis in the ground model is not an S‐topology. This supplements the previous work due to Stevo Todor?evi? [25]. 相似文献
6.
Noriyuki Yoshii Yoshimichi Andoh Susumu Okazaki 《Journal of computational chemistry》2020,41(9):940-948
We derived a new expression for the electrostatic interaction of three-dimensional charge-neutral systems with two-dimensional periodic boundary conditions (slab geometry) using a fast multipole method (FMM). Contributions from all the image cells are expressed as a sum of real and reciprocal space terms, and a self-interaction term. The reciprocal space contribution consists of two parts: zero and nonzero terms of the absolute value of the reciprocal lattice vector. To test the new expressions, electrostatic interactions were calculated for a randomly placed charge distribution in a cubic box and liquid water produced by molecular dynamics calculation. The accuracy could be controlled by the degree of expansion of the FMM. In the present expression, the computational complexity of the electrostatic interaction of N-particle systems is order N, which is superior to that of the conventional two-dimensional periodic Ewald method for a slab geometry and the particle mesh Ewald method with a large empty space at an interface of the unit cell. © 2020 Wiley Periodicals, Inc. 相似文献
7.
D. Nakamura K. Okazaki I. A. Palani M. Higashihata T. Okada 《Applied Physics A: Materials Science & Processing》2011,103(4):959-963
Single-crystalline ZnO nanowires on a sapphire substrate have been synthesized by a nanoparticle-assisted pulsed-laser deposition
(NAPLD) using a pure and Sb2O3 doped ZnO target. Low density and vertically well-aligned ZnO nanowires were grown on hexagonal cone-shape ZnO cores by introduction
of a ZnO buffer layer. More than 90% of the ZnO cores of the Sb-induced ZnO nanowires are formed in the same size of 400 nm.
The ZnO nanowires consist of single-crystalline wurtzite ZnO crystal and grow along [0001] direction. The room-temperature
photoluminescence spectrum exhibited a strong ultraviolet emission at around 380 nm and a relatively low broad band emission
in the visible region, indicating a low concentration of structural defect in the nanowires. Sb can be used as one of the
effective additives to control the morphology and alignment of ZnO nanowires synthesized by NAPLD. 相似文献
8.
Mari Iizuka Shoju Fukushima Yuki Goto Masaaki Okazaki Hideo Sawada Masato Yoshida 《Colloid and polymer science》2013,291(3):595-601
Head-to-head-type styrene and substituted styrene dimers bearing two fluoroalkyl end-groups have been efficiently synthesized by a simple reaction of perfluoroalkyl iodide with styrene under radical conditions as a mixture of meso and racemic forms. The meso form obtained from the mixture by recrystallization gave a crystal suitable for X-ray diffraction study and the crystal structure was found to be based on π-stacking of benzene rings and aggregation of fluoroalkyl chains. Dynamic light scattering measurements showed that meso-styrene dimers bearing two fluoroalkyl end-groups can form the nanometer size-controlled self-assemblies through the intermolecular π-stacking of benzene rings and aggregation of end-capped fluoroalkyl groups in methanol. Figure
Self-assembled meso-perfluorohexylated styrene dimer [C6F13–CH2CHPh–CHPh–CH2–C6F13] based on π-stacking of benzene rings and aggregation of fluoroalkyl chains: Fluorous domains are constructed by self-assembly of fluoroalkyl chains. 相似文献
9.
Nobuhiro Takeda Norihiro Tokitoh Renji Okazaki 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):633-636
The first rotational isomers of stable selenoaldehydes are synthesized by deselenation of cyclic polyselenides having an efficient steric protection group, 2, 4, 6-tris[bis(trimetylsilyl)methyl]phenyl (Tbt). Reactions of these selenoaldehydes with W(CO)5.THF gives the corresponding η1-selenoaldehyde tungsten complexes, the structures of which are established by X-ray crystallography. 相似文献
10.
Masaharu Okazaki Taizo Ono Kenji Komaguchi Nobuaki Ohta Haruhiko Fukaya Kazumi Toriyama 《Applied magnetic resonance》2009,36(1):89-95
Room temperature fluorine electron nuclear double resonance (ENDOR) has been successfully observed for several superstable
fluorocarbon radicals ·C(C2F4R)(i-C3F7)2 in solution. Three radicals were employed in which CF3, F, and O-c-C6F10SO3C2F5 were introduced as R, and all the hyperfine couplings (hfcs) obtained by ENDOR were assigned with the help of ESR simulation
and ab initio MO calculation. In case of ·C(i-C3F7)3 large 13C and considerable β-fluorine couplings suggest the nonplaner arrangement for the central and three carbons at the β-position, in spite of the
fact that all the methyl fluorine show the same hfc. Therefore, a rapid puckering motion along the C3 axis together with the methyl rotation should average the hfc’s of the 18 fluorine nuclei to give the same value. When one
of the CF3 groups is substituted with an F nucleus, the five CF3 groups give two hfc values, suggesting some dynamics still exists for the molecular frame. When a large group, O-c-C6F10SO3C2F5, is substituted for CF3, all the five CF3 groups become nonequivalent and the ENDOR signal becomes intensive and sharp even at 290 K, indicating that the molecular
frame becomes rigid. The relation between the ENDOR spectra of these systems and the intramolecular dynamics is discussed. 相似文献