全文获取类型
收费全文 | 1403篇 |
免费 | 72篇 |
国内免费 | 1篇 |
专业分类
化学 | 1041篇 |
晶体学 | 2篇 |
力学 | 24篇 |
数学 | 204篇 |
物理学 | 205篇 |
出版年
2024年 | 5篇 |
2023年 | 33篇 |
2022年 | 36篇 |
2021年 | 31篇 |
2020年 | 56篇 |
2019年 | 65篇 |
2018年 | 30篇 |
2017年 | 29篇 |
2016年 | 67篇 |
2015年 | 62篇 |
2014年 | 50篇 |
2013年 | 62篇 |
2012年 | 102篇 |
2011年 | 93篇 |
2010年 | 58篇 |
2009年 | 34篇 |
2008年 | 65篇 |
2007年 | 84篇 |
2006年 | 70篇 |
2005年 | 82篇 |
2004年 | 58篇 |
2003年 | 25篇 |
2002年 | 25篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 17篇 |
1998年 | 12篇 |
1997年 | 15篇 |
1996年 | 11篇 |
1994年 | 8篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1990年 | 6篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1983年 | 6篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 9篇 |
1976年 | 11篇 |
1975年 | 6篇 |
1973年 | 10篇 |
1968年 | 3篇 |
1939年 | 4篇 |
1938年 | 4篇 |
1937年 | 6篇 |
1934年 | 3篇 |
1932年 | 3篇 |
排序方式: 共有1476条查询结果,搜索用时 15 毫秒
921.
Yang Yang Remigijus Leipus Jonas Šiaulys Yuquan Cang 《Journal of Mathematical Analysis and Applications》2011,383(1):215-225
This paper investigates the finite-time ruin probability in the dependent renewal risk model, where the claim sizes are independent and identically distributed random variables with strongly subexponential tails, and the interarrival times are negatively dependent. We establish an asymptotic estimate, which holds uniformly for the time horizon varying in the positive half line. 相似文献
922.
We obtain criteria for the weak convergence of distributions of a set of strongly additive functions f x to the binomial law. We consider the case where f x (p)??{0, 1} for every prime p. Some examples are presented. 相似文献
923.
Arūnas Jagminas Rimas Ragalevičius Kestutis Mažeika Jonas Reklaitis Vitalija Jasulaitienė Algis Selskis Dalis Baltrūnas 《Journal of Solid State Electrochemistry》2010,14(2):271-277
We report here on the synthesis of homogenous, well-adherent composite film of Fe2O3/SiO2, up to 7 μm thick, on the titanium substrate by anodic treatment optimized for an aqueous suspension of K2O·SiO2 and Fe2O3 powder under galvanostatic conditions. The end products were characterized by scanning electron microscopy, energy-dispersive X-ray, X-ray powder diffractometry, X-ray photoelectron spectroscopy, and Mössbauer spectroscopy, concluding that the formation of composite coating at the SiO2 to Fe2O3 ratio of approximately 1:1 proceeds just after formation of a thin TiO2 layer with Fe2O3 particle inclusions without transformations via an electrophoresis deposition of negatively charged Fe2O3 species enveloped by silica ions. 相似文献
924.
Tomas Ya. Azizov Jussi Behrndt Peter Jonas Carsten Trunk 《Integral Equations and Operator Theory》2009,63(2):151-163
For closed linear operators or relations A and B acting between Hilbert spaces and the concepts of compact and finite rank perturbations are defined with the help of the orthogonal projections P
A
and P
B
in onto the graphs of A and B. Various equivalent characterizations for such perturbations are proved and it is shown that these notions are a natural
generalization of the usual concepts of compact and finite rank perturbations.
Sadly, our colleague and friend Peter Jonas passed away on July, 18th 2007. 相似文献
925.
A methodology for assessing eco-efficiency in logistics networks 总被引:2,自引:0,他引:2
J. Quariguasi Frota Neto G. Walther J. Bloemhof J.A.E.E. van Nunen T. Spengler 《European Journal of Operational Research》2009
Recent literature on sustainable logistics networks points to two important questions: (i) How to spot the preferred solution(s) balancing environmental and business concerns? (ii) How to improve the understanding of the trade-offs between these two dimensions? We posit that a visual exploration of the efficient frontier and trade-offs between profitability and environmental impacts are particularly suitable to answer these two questions. The visual representation of the efficient frontier, however, presents two challenges. The first is to obtain a good approximation for such frontier without enumerating all extreme efficient solutions. The second is to obtain a good visual representation of the efficient frontier. We propose a two-phased heuristic to handle these two problems. The algorithm is designed for the multi-objective linear problem with three objectives: minimize costs, cumulative energy demand and waste in a reverse logistics network. We illustrate our approach by designing a complex recycling logistics network in Germany. 相似文献
926.
Lukas Englert Andreas Stoy Dr. Merle Arrowsmith Dr. Jonas H. Muessig Melanie Thaler Andrea Deißenberger Alena Häfner Dr. Julian Böhnke Dr. Florian Hupp Dr. Jens Seufert Dr. Jan Mies Dr. Alexander Damme Dr. Theresa Dellermann Kai Hammond Dr. Thomas Kupfer Dr. Krzysztof Radacki Torsten Thiess Prof. Dr. Holger Braunschweig 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8612-8622
A series of 22 new bis(phosphine), bis(carbene), and bis(isonitrile) tetrahalodiborane adducts has been synthesized, either by direct adduct formation with highly sensitive B2X4 precursors (X=Cl, Br, I) or by ligand exchange at stable B2X4(SMe2)2 precursors (X=Cl, Br) with labile dimethylsulfide ligands. The isolated compounds have been fully characterized using NMR spectroscopy, elemental analysis, and, for 20 of these compounds, single-crystal X-ray diffraction, revealing an unexpected variation in the bonding motifs. In addition to the classical B2X4L2 diborane(4) bis-adducts, certain more sterically demanding carbene ligands induce a halide displacement which led to the first halide-bridged monocationic diboron species, [B2X3L2]A (A=BCl4, Br, I). Furthermore, low-temperature 1:1 reactions of B2Cl4 with sterically demanding N-heterocyclic carbenes led to the formation of kinetically unstable mono-adducts, one of which was structurally characterized. A comparison of the NMR spectra and structural data of new and literature-known bis-adducts shows several trends pertaining to the nature of the halides and the stereoelectronic properties of the Lewis bases employed. 相似文献
927.
Cover Picture: O2 Activation and Double CH Oxidation by a Mononuclear Manganese(II) Complex (Angew. Chem. Int. Ed. 2/2016)
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
928.
929.