全文获取类型
收费全文 | 362篇 |
免费 | 17篇 |
专业分类
化学 | 302篇 |
晶体学 | 2篇 |
力学 | 6篇 |
数学 | 21篇 |
物理学 | 48篇 |
出版年
2023年 | 8篇 |
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 11篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 13篇 |
2014年 | 19篇 |
2013年 | 17篇 |
2012年 | 38篇 |
2011年 | 35篇 |
2010年 | 19篇 |
2009年 | 13篇 |
2008年 | 33篇 |
2007年 | 24篇 |
2006年 | 25篇 |
2005年 | 18篇 |
2004年 | 15篇 |
2003年 | 6篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 4篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有379条查询结果,搜索用时 15 毫秒
371.
Yasuna Kawasaki Keita Deguchi Satoshi Demura Tohru Watanabe Hiroyuki Okazaki Toshinori Ozaki Takahide Yamaguchi Hiroyuki Takeya Yoshihiko Takano 《Solid State Communications》2012,152(13):1135-1138
Phase diagrams of as-grown and O2-annealed FeTe1?xSex determined from magnetic susceptibility measurement were obtained. For as-grown samples, the antiferromagnetic order was fully suppressed in the range region x≥0.15, and weak superconductivity appeared when x≥0.1. Beginning at x=0.5, weak superconductivity was found to evolve into bulk superconductivity. Interestingly, for O2-annealed samples, complete suppression of magnetic order and the occurrence of bulk superconductivity were observed when x≥0.1. We found that O2-annealing induces bulk superconductivity for FeTe1?xSex. Oxygen probably plays a key role in the suppression of the magnetic order and the appearance of bulk superconductivity. 相似文献
372.
Mika Katayama Keita Sasagawa Hiroshi Yamataka 《Journal of Physical Organic Chemistry》2012,25(8):680-685
The reaction of PhCOCH2Cl with OH– gave the expected α‐substituted alcohol (PhCOCH2OH) in addition to three dimer products. To clarify whether the substitution product is formed by direct SN2 or via carbonyl addition, the reaction of PhCOCH2Cl and OMe– was examined. The reaction gave two products, PhCOCH2OH as the major product after acid hydrolysis and PhCOCH2OMe as the minor product. An electron‐withdrawing substituent on the phenyl ring enhanced the overall reactivity and gave more alcohol than ether. It was concluded that the alcohol was formed via carbonyl addition‐epoxidation route, whereas the ether was formed by the direct substitution route. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
373.
Madhu Menon Ernst Richter Padma Raghavan Keita Teranishi 《Superlattices and Microstructures》2000,27(5-6):577-581
The stability of quasi-one-dimensional structures of carbon is investigated using a generalized tight-binding molecular-dynamics scheme. Large-scale simulations are made possible by the parallel implementation of the diagonalization routines. Our results show that these structures can be stable provided that their geometries consist of a core of four-fold coordinated atoms, surrounded by a three-fold coordinated outer surface accommodating one of the most stable reconstructions of bulk diamond structure. 相似文献
374.
We derive an expression for the effectivegravitational mass for any closed spacelike 2-surface.This effective gravitational energy is defined directlythrough the geometrical quantity of the freely falling 2-surface and thus is well adapted to intuitiveexpectation that the gravitational mass should bedetermined by the motion of a test body moving freely inthe gravitational field. We find that this effective gravitational mass has a reasonable positivevalue for a small sphere in the non-vacuum space-timesand can be negative for the vacuum case. Further, thiseffective gravitational energy is compared with the quasi-local energy based on the (2 + 2)formalism of General Relativity. Although some gaugefreedoms exist, analytic expressions of the quasi-localenergy for vacuum cases are the same as the effective gravitational mass. Especially, we see that thecontribution from the cosmological constant is the samein general cases. 相似文献
375.
Dr. Kazuto Suzuki Dr. Joshua Kyle Stanfield Dr. Keita Omura Dr. Yuma Shisaka Dr. Shinya Ariyasu Chie Kasai Dr. Yuichiro Aiba Dr. Hiroshi Sugimoto Prof. Dr. Osami Shoji 《Angewandte Chemie (International ed. in English)》2023,62(13):e202215706
Catching the structure of cytochrome P450 enzymes in flagrante is crucial for the development of P450 biocatalysts, as most structures collected are found trapped in a precatalytic conformation. At the heart of P450 catalysis lies Cpd I, a short-lived, highly reactive intermediate, whose recalcitrant nature has thwarted most attempts at capturing catalytically relevant poses of P450s. We report the crystal structure of P450BM3 mimicking the state in the precise moment preceding epoxidation, which is in perfect agreement with the experimentally observed stereoselectivity. This structure was attained by incorporation of the stable Cpd I mimic oxomolybdenum mesoporphyrin IX into P450BM3 in the presence of styrene. The orientation of styrene to the Mo-oxo species in the crystal structures sheds light onto the dynamics involved in the rotation of styrene to present its vinyl group to Cpd I. This method serves as a powerful tool for predicting and modelling the stereoselectivity of P450 reactions. 相似文献
376.
Dewi Yana Tomoko Shimizu Keita Hamasaki Hisakazu Mihara Akihiko Ueno 《Macromolecular rapid communications》2002,23(1):11-15
A cyclodextrin‐peptide hybrid (17NNβ) bearing two naphthalene units in the peptide side chain has been designed and synthesized as a novel chemosensor molecule. Circular dichroism study of the compound revealed that the peptide has α‐helix structure with a helix content of 41%. The peptide revealed both monomer and excimer emission and the intensity of the excimer emission increased while that of the monomer emission decreased upon addition of the guest compound. This behavior was observed for various guest molecules, suggesting that the system can be used for detecting molecules in aqueous solution. 相似文献
377.
378.
Dr. Yoshiyuki Manabe Yuki Iizuka Ryuku Yamamoto Keita Ito Kanae Hatano Dr. Kazuya Kabayama Prof. Koichi Fukase 《Angewandte Chemie (International ed. in English)》2023,62(30):e202304779
Antibody dynamics on membranes, such as endocytosis and clustering, are vital in determining antibody functions. In this study, we demonstrated that glycan conjugation can modulate antibody dynamics through the glycan–lectin interaction to regulate its potency. The anti-HER2 antibody, an anti-breast-cancer antibody, was conjugated with galactose-containing N-glycan, and its internalization was suppressed by interaction with galectin-3, leading to enhanced complement-dependent cytotoxic (CDC) activity. This glycan–antibody conjugate is proposed as a new approach to modulate antibody activity and may provide an alternative strategy for redeveloping antibody drugs that do not exhibit sufficient activity. 相似文献
379.
Hawa Keita Prof. Simon J. Meek 《Angewandte Chemie (International ed. in English)》2023,62(34):e202306277
A practical method for the preparation of quaternary and tertiary allyl-substituted heteroarenes by site-selective couplings of heteroaryl nitriles and allylic nucleophiles is disclosed. Transformations utilize readily accessible stable reagents, proceed in the presence of a Lewis base activator, and undergo aryl-C(sp3) quaternary and tertiary carbon formation with high γ-selectivity (up to >98 : 2 γ : α). 相似文献