全文获取类型
收费全文 | 3723篇 |
免费 | 117篇 |
国内免费 | 19篇 |
专业分类
化学 | 2806篇 |
晶体学 | 21篇 |
力学 | 66篇 |
数学 | 515篇 |
物理学 | 451篇 |
出版年
2022年 | 18篇 |
2021年 | 37篇 |
2020年 | 41篇 |
2019年 | 51篇 |
2018年 | 32篇 |
2017年 | 23篇 |
2016年 | 79篇 |
2015年 | 102篇 |
2014年 | 75篇 |
2013年 | 137篇 |
2012年 | 186篇 |
2011年 | 226篇 |
2010年 | 161篇 |
2009年 | 113篇 |
2008年 | 219篇 |
2007年 | 203篇 |
2006年 | 204篇 |
2005年 | 200篇 |
2004年 | 137篇 |
2003年 | 108篇 |
2002年 | 117篇 |
2001年 | 60篇 |
2000年 | 71篇 |
1999年 | 64篇 |
1998年 | 58篇 |
1997年 | 67篇 |
1996年 | 59篇 |
1995年 | 56篇 |
1994年 | 53篇 |
1993年 | 64篇 |
1992年 | 58篇 |
1991年 | 25篇 |
1990年 | 33篇 |
1989年 | 26篇 |
1988年 | 32篇 |
1987年 | 40篇 |
1986年 | 33篇 |
1985年 | 58篇 |
1984年 | 24篇 |
1983年 | 31篇 |
1982年 | 46篇 |
1980年 | 38篇 |
1978年 | 28篇 |
1977年 | 39篇 |
1976年 | 18篇 |
1974年 | 19篇 |
1973年 | 20篇 |
1972年 | 21篇 |
1971年 | 21篇 |
1969年 | 21篇 |
排序方式: 共有3859条查询结果,搜索用时 0 毫秒
11.
12.
13.
Marko D. Mihovilovic Bernhard Müller Markus Spina Arjumand I. Durrani Peter Stanetty Georg Dazinger Karl Kirchner 《Monatshefte für Chemie / Chemical Monthly》2006,137(6):785-794
Summary. Recombinant Escherichia coli overexpressing Pseudomonas sp. NCIMB 9872 cyclopentanone monooxygenase (CPMO, EC 1.14.13.16) and Acinetobacter sp. NCIMB 9871 cyclohexanone monooxygenase (CHMO, EC 1.14.13.22) have been utilized in whole-cell Baeyer-Villiger biotransformations of prochiral bicycloketones. A significant difference in substrate acceptance and stereoselectivity was
observed for bicyclo[3.3.0] and bicyclo[4.3.0] substrates. A plausible mechanism of these transformations was established
by means of high level DFT/B3LYP calculations suggesting an essential difference in electronic requirements for a successful
enzymatic conversion, which was similarly encountered in recombinant whole-cell mediated biooxidations. Some of the lactones
produced in the biocatalytic Baeyer-Villiger oxidation represent key intermediates for the synthesis of indole alkaloids. 相似文献
14.
3rd International Conference on Trace Element Speciation in Biomedical, Nutritional and Environmental Sciences 相似文献
15.
Vladimir B. Arion Alexey A. Nazarov Christian G. Hartinger Gerald Giester Bernhard K. Keppler 《应用有机金属化学》2003,17(9):723-724
For the unsymmetrical title compound, 1‐bromo‐1′‐[(2S)‐N‐(1‐hydroxy‐3‐methylbutane‐2‐yl)]‐ferroceneamide, two independent molecules were found in the asymmetric unit. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
16.
17.
Bernhard Krötz 《Japanese Journal of Mathematics》2007,2(2):303-311
In this paper we raise a question about the boundary of the crown domain of a Riemannian symmetric space X. In case X is of Hermitian type we give an affirmative answer. 相似文献
18.
19.
Bernhard Von Stengel 《Annals of Operations Research》1988,16(1):161-183
This paper integrates and extends the theory of the decomposition of multiattribute expected-utility functions based on utility independence. In a preliminary section, the standard decision model of expected utility is briefly discussed, including the fact that the decision maker's preference forlotteries with two outcomes determines the utility function uniquely. The decomposition possibilities of a utility function are captured by the concept ofautonomous sets of attributes, an affine separability of some kind known as generalized utility independence.Overlapping autonomous sets lead to biaffine-associative, i.e.multiplicative oradditive decompositions. The multiplicative representation shows that autonomy has strongerclosure properties than utility independence, for instance with respect to set-theoretic difference. Autonomy is also a concept with a wider scope since it applies to the decomposition of Boolean functions, games and a number of other topics in combinatorial optimization. This relationship to the well-known theory ofsubstitution decomposition in discrete mathematics also reveals a kind of discrete core behind the decomposition of utility functions. The entirety of autonomous sets can be represented by a compact data structure, the so-calledcomposition tree, which frequently corresponds to a natural hierarchy of attributes. Multiplicative/additive ormulti-affine functions correspond to the hierarchy steps. The known representation of multi-affine functions is shown to be given by aMoebius inversion formula. The entire approach has the advantage that it allows the application of more sophisticated representation methods on a detailed level, whereas it employs onlyfinite set theory andarithmetic on the main levels in the hierarchy. 相似文献
20.
Timerbaev AR Aleksenko SS Polec-Pawlak K Ruzik R Semenova O Hartinger CG Oszwaldowski S Galanski M Jarosz M Keppler BK 《Electrophoresis》2004,25(13):1988-1995
Characterizing how platinum metallocomplexes bind to human serum albumin (HSA) is essential in evaluating anticancer drug candidates. Using cisplatin as a reference complex, the application of capillary electrophoresis (CE) to reliably assess drug/HSA interactions was validated. Since this complex is small compared to the size of the protein, the binding response could only be recognized when applying CE coupled to a (platinum) metal-specific mode of detection, namely inductively coupled plasma-mass spectrometry (ICP-MS). This coupling allowed for confirmation of a specific affinity of cisplatin and novel Pt complexes to HSA, measurement of the kinetics of binding reactions, and determination of the number of drug molecules attached to the protein. As the cisplatin/HSA molar ratio increased, the reaction rate became faster with a maximum on the kinetic curve appearing at about 50 h of incubation at 20 times excess of cisplatin. The reaction was characterized as a pseudo-first order reaction with the rate constant k = 0.003 min(-1) at 37 degrees C. When incubated with a 20-fold excess of cisplatin, HSA bound up to 10 mol of Pt per mol of the protein. This is indicative for a strong metal-protein coordination occurring at several HSA sites other than the only protein cysteine residue. Structural analogs of cisplatin, bearing aminoalcohol ligands, showed comparable protein binding reactivity and stoichiometry but a common equilibrium was not reached even after one week of incubation. Also apparent was a two-step mechanism of the binding reaction. Results demonstrated the suitability of CE-ICP-MS as a rapid assay for high-throughput studying of drug/HSA interactions. 相似文献