全文获取类型
收费全文 | 1065篇 |
免费 | 18篇 |
国内免费 | 1篇 |
专业分类
化学 | 592篇 |
晶体学 | 5篇 |
力学 | 114篇 |
数学 | 137篇 |
物理学 | 236篇 |
出版年
2023年 | 5篇 |
2022年 | 31篇 |
2021年 | 44篇 |
2020年 | 21篇 |
2019年 | 27篇 |
2018年 | 33篇 |
2017年 | 27篇 |
2016年 | 33篇 |
2015年 | 30篇 |
2014年 | 50篇 |
2013年 | 92篇 |
2012年 | 49篇 |
2011年 | 81篇 |
2010年 | 51篇 |
2009年 | 34篇 |
2008年 | 59篇 |
2007年 | 39篇 |
2006年 | 33篇 |
2005年 | 31篇 |
2004年 | 35篇 |
2003年 | 18篇 |
2002年 | 21篇 |
2001年 | 16篇 |
2000年 | 12篇 |
1998年 | 11篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1979年 | 6篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1974年 | 8篇 |
1973年 | 11篇 |
1972年 | 7篇 |
1971年 | 19篇 |
1970年 | 14篇 |
1969年 | 7篇 |
1968年 | 7篇 |
1967年 | 9篇 |
1966年 | 4篇 |
排序方式: 共有1084条查询结果,搜索用时 323 毫秒
71.
Prakash Sista Mahesh P. Bhatt Ashton R. Mccary Hien Nguyen Jing Hao Michael C. Biewer Mihaela C. Stefan 《Journal of polymer science. Part A, Polymer chemistry》2011,49(10):2292-2302
Poly{4,8‐bis(4‐decylphenylethynyl)benzo[1,2‐b:4,5‐b′]dithiophene} ( P1 ) homopolymer and poly{4,8‐bis(4‐decylphenylethynyl)benzo[1,2‐b:4,5‐b′]dithiophene ‐alt‐thiophene} ( P2 ) alternating copolymer have been synthesized by Stille coupling polymerization. The field‐effect mobilities of both polymers were measured on both untreated and silane‐treated OFET devices. Various silanes were selected to allow an incremental increase in the hydrophobicity of the silicon dioxide dielectric. A direct correlation was observed between the hydrophobicity of the silicon dioxide dielectric surface and the enhancement of the field‐effect mobilities. The highest mobilities for both polymers were measured on the OFET devices treated with heptadecafluoro‐1,1,2,2‐tetrahydro‐decyl‐1‐trimethoxysilane (FS) which generated the most hydrophobic surface. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
72.
73.
Valentina Uivarosi Mihaela Badea Rodica Olar Dana Marinescu Teodor Octavian Nicolescu George Mihai Nitulescu 《Journal of Thermal Analysis and Calorimetry》2011,105(2):645-650
Three new complexes with ligands belong to the fluoroquinolone class having the general formula [RuL2Cl2]Cl nH2O ((1) L: norfloxacin (nf), n = 4; (2) L: ciprofloxacin (cp), n = 3; (3) L: enrofloxacin (enro), n = 5) were synthesized and characterized by chemical analysis UV–Vis and IR spectroscopy. In all complexes fluoroquinolone
derivative acts as bidentate chelate ligand. The thermal behavior steps were investigated in synthetic air flow. The thermal
transformations are complex processes according to TG and DTG curves including dehydration, quinolone derivative degradation,
as well as RuCl3 conversion in RuO2. 相似文献
74.
Mihaela Gulea Małgorzata Kwiatkowska Piotr Łyżwa Remi Legay Annie-Claude Gaumont Piotr Kiełbasiński 《Tetrahedron: Asymmetry》2009,20(3):293-297
The Michael addition of selected sulfur and nitrogen nucleophiles to a chiral non-racemic 2-phosphono-2,3-didehydrothiolane S-oxide is fully diastereoselective. The enantiomeric excesses of the adducts obtained could be determined by 31P NMR spectroscopy using (R)-(+)-tert-butyl(phenyl)phosphinothioic acid as a chiral solvating agent. The addition of thiophenol was monitored by 31P NMR spectroscopy which made it possible to observe the formation and evolution of the kinetic and thermodynamic adducts in the reaction mixture. The structures of both enantiomeric thiophenol adducts have been determined by X-ray analysis. 相似文献
75.
V. G. Krivokhizhin S. P. Kurlovich V. V. Sanadze I. A. Savin A. V. Sidorov N. B. Skachkov 《Zeitschrift fur Physik C Particles and Fields》1987,36(1):51-59
A new method of QCD-analysis of singlet and nonsinglet structure functions based on their expansion in orthogonal Jacobi polynomials is proposed. An accuracy of the method is studied and its application is demonstrated using the structure functionF 2(x, Q 2) obtained by the EMC Collaboration from measurements with an iron target. 相似文献
76.
Alberto Damiano Daniele Struppa Adrian Vajiac Mihaela Vajiac 《Journal of Geometric Analysis》2009,19(2):288-300
We introduce the notion of antisyzygies, which studies the inverse problem of finding a system of PDEs, given compatibility
conditions. The system obtained possesses the property of removability of compact singularities. We write explicit computations
in the cases of the Cauchy-Fueter system and Maxwell’s system for electromagnetism, and we conclude with a study of systems
of non-maximal rank.
相似文献
77.
78.
Andreas H. Hamel Birgit Rudloff Mihaela Yankova 《Mathematics and Financial Economics》2013,7(2):229-246
New versions of the set-valued average value at risk for multivariate risks are introduced by generalizing the well-known certainty equivalent representation to the set-valued case. The first ’regulator’ version is independent from any market model whereas the second version, called the market extension, takes trading opportunities into account. Essential properties of both versions are proven and an algorithmic approach is provided which admits to compute the values of both versions over finite probability spaces. Several examples illustrate various features of the theoretical constructions. 相似文献
79.
80.
Let G be a simply connected Chevalley group of type D
n
, E
n
or G2. In this paper, we show that the minimal representation of G is unique for types D
n
and E
n
and it does not exist for the type G2. 相似文献