全文获取类型
收费全文 | 461篇 |
免费 | 16篇 |
国内免费 | 1篇 |
专业分类
化学 | 371篇 |
晶体学 | 4篇 |
力学 | 7篇 |
数学 | 24篇 |
物理学 | 72篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 27篇 |
2021年 | 26篇 |
2020年 | 10篇 |
2019年 | 18篇 |
2018年 | 14篇 |
2017年 | 11篇 |
2016年 | 18篇 |
2015年 | 17篇 |
2014年 | 16篇 |
2013年 | 20篇 |
2012年 | 34篇 |
2011年 | 24篇 |
2010年 | 29篇 |
2009年 | 25篇 |
2008年 | 30篇 |
2007年 | 19篇 |
2006年 | 21篇 |
2005年 | 15篇 |
2004年 | 23篇 |
2003年 | 14篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 9篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1923年 | 2篇 |
排序方式: 共有478条查询结果,搜索用时 46 毫秒
101.
102.
ABSTRACTHigh pressure research can be used to aid in answering why some polypeptide chains reversibly unfold and others adopt a misfolding conformation culminating in aggregation. This topic is one of the fundamental questions in biology that we seek to understand, and for that, we have been experimentally applying pressure to proteins for the last 20 years. Here, we exemplify how pressure research should be used to identify preamyloidogenic protein intermediates as well as to dissociate supramolecular complexes. We believe that the applications of high pressure to understand the behavior of proteins are diverse and can help biologists answer fundamental questions of biomedical relevance. 相似文献
103.
104.
105.
The conceptual basis for the development of mitochondrial targeting as a novel therapeutic strategy for both chemotherapy and photochemotherapy of neoplastic diseases rests on the observation that enhanced mitochondrial membrane potential is a common tumor cell phenotype. The potential of this strategy is highlighted by the fact that the toxic effects associated with a number of cationic dyes known to localize in energized cell mitochondria are much more pronounced in tumor cells than in normal cells. Here we evaluate the phototoxic properties of four bromine derivatives of rhodamine-123 toward human uterine sarcoma (MES-SA) and green monkey kidney (CV-1) cells and compare the degrees of tumor cell selectivity associated with these dyes with those associated with two model mitochondrial triarylmethanes (crystal violet and ethyl violet). Selective phototoxicity toward tumor cells was found to be highly dependent upon the lipophilic/hydrophilic character of the cationic photosensitizer. Our experimental data have indicated that the probability of success of mitochondrial targeting in (photo)chemotherapy of neoplastic diseases is higher when the octan-1-ol/water partition coefficient of the drug candidate falls within approximately two orders of magnitude from that of the prototypical mitochondria-specific dye rhodamine-123. 相似文献
106.
Magno Agostinho Andrei Banu Pierre Braunstein Richard Welter Xavier Morise 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):m81-m86
Three new palladium complexes containing a difunctional P,N‐chelate, namely tris(chloro{[1‐methyl‐1‐(6‐methyl‐2‐pyridyl)ethoxy]diphenylphospine‐κ2N,P}methylpalladium(II)chloroform solvate, 3[Pd(CH3)Cl(C21H22NOP)]·CHCl3, (III), dichloro[2‐(2,6‐dimethylphenyl)‐6‐(diphenylphosphinomethyl)pyridine‐κ2N,P]palladium(II), [PdCl2(C26H24NP)], (IV), and chloro[2‐(2,6‐dimethylphenyl)‐6‐(diphenylphosphinomethyl)pyridine‐κ2N,P]methylpalladium(II), [Pd(CH3)Cl(C26H24NP)], (V), are reported. Geometric data and the conformations of the ligands around the metal centers, as well as slight distortions of the Pd coordination environments from idealized square‐planar geometry, are discussed and compared with the situations in related compounds. Non‐conventional hydrogen‐bond interactions (C—H⋯Cl) have been found in all three complexes. Compound (III) is the first six‐membered chloro–methyl–phosphinite P,N‐type PdII complex to be structurally characterized. 相似文献
107.
Mota AJ Dedieu A Kuhn P Matt D Welter R Neuburger M 《Dalton transactions (Cambridge, England : 2003)》2005,(19):3155-3160
Selective N(2)-binding of 3-methyl-1-phenyl-4-(triphenylphosphoranylidene)-2-pyrazolin-5-one (L) has been found in two palladium(II) complexes, [PdCl(2)L(2)](2) and [Pd(o-C(6)H(4)CH(2)NMe(2))Cl](3). X-Ray diffraction studies show that the pyrazole rings lie almost perpendicular to the coordination plane. In both complexes the metal atom is located out of the plane defined by the pyrazole ring(s)(dihedral angle between the plane and the Pd-N vector approximately 30 degrees). To investigate the origin of this distortion, a theoretical study was carried out on a simplified model of complex , where a single pyrazolone ligand was replaced by NH(3). From this study it could be inferred that the out-of-plane distortion mainly involves weak, electrostatic interactions between a chlorine atom and an ortho-aromatic H atom of the N(1)-linked phenyl group, as well as between the other chlorine atom and an ortho-aromatic H atom of the PPh(3) group. 相似文献
108.
Rodrigo S. Bitzer Carlos A. L. Filgueiras José Guilherme S. Lopes Paulo Sérgio Santos Marcelo H. Herbst 《Transition Metal Chemistry》2005,30(5):636-642
We have investigated the reactions between 2,3,5,6-tetrakis(α-pyridyl)pyrazine (TPP) and CrCl3 · 6H2O in 1:2 and 2.6:1 (CrIII:TPP) stoichiometric ratios. The resulting products, [Cr(TPP)Cl3] (1) and [(CrCl3)2-μ-TPP] (2), respectively, have been characterized by elemental and thermogravimetric analyses, molar conductivities, vibrational and electronic spectroscopy, and powder e.p.r. spectroscopy at room temperature. In both (1) and (2), TPP behaves as a tridentate ligand. Whereas (1) is a monometallic species with three uncoordinated nitrogen atoms, (2) is bimetallic with TPP as a bridging ligand. 相似文献
109.
110.
Rodrigues Ana Luísa Marques Rosa Dias Maria Isabel Prudêncio Maria Isabel Cardoso Guilherme Russo Dulce Fontanals Núria Rafel Soriano Eni 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(3):1397-1408
Journal of Radioanalytical and Nuclear Chemistry - Modern mining activities often leads to destruction of archaeological records, making difficult to date the contexts and tools. In this work, a... 相似文献