全文获取类型
收费全文 | 314篇 |
免费 | 32篇 |
国内免费 | 1篇 |
专业分类
化学 | 236篇 |
力学 | 5篇 |
数学 | 59篇 |
物理学 | 47篇 |
出版年
2023年 | 8篇 |
2022年 | 11篇 |
2021年 | 11篇 |
2020年 | 17篇 |
2019年 | 13篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 19篇 |
2015年 | 13篇 |
2014年 | 25篇 |
2013年 | 29篇 |
2012年 | 20篇 |
2011年 | 25篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 14篇 |
2007年 | 6篇 |
2006年 | 10篇 |
2005年 | 13篇 |
2004年 | 9篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 3篇 |
1995年 | 2篇 |
1993年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1943年 | 1篇 |
1935年 | 2篇 |
1933年 | 2篇 |
1932年 | 1篇 |
1931年 | 2篇 |
排序方式: 共有347条查询结果,搜索用时 15 毫秒
1.
Summary We present an approximation method of a space-homogeneous transport equation which we prove is convergent. The method is very promising for numerical computation. Comparison of a numerical computation with an exact solution is given for the Master equation. 相似文献
2.
The reaction between TiO(2+) and ONOOH in 0.9 M H(2)SO(4) provides evidence for direct formation, previously unobserved, of a HOONO-metal complex. The reaction proceeds via formation of an end-on complex (k = 3.0 x 10(2) M(-1) s(-1)) that rearranges to form a side-on complex (k approximately equal to 20 s(-1)). With ONOOH in excess, this rearrangement proceeds more slowly (k approximately equal to 0.1 s(-1)), probably because multiple hydrogen oxoperoxonitrate molecules form end-on complexes with oxotitanium(IV) and hinder rearrangement to the side-on complex. The absorption spectrum of the final product is that of TiO(2)(2+). Presumably, during the rearrangement or later, NO+ is lost. 相似文献
3.
A. K. Wick 《Helvetica chimica acta》1966,49(6):1748-1754
The condensation of 1-aminoanthraquinone to 1,1′-diamino-2,2′-dianthraquinonyl in a melt of anhydrous aluminium chloride and moist pyridine has been reinvestigated. By a similar procedure under anhydrous conditions the sodium salt of 1-aminoanthraquinone-2-sulfonic acid yielded the sodium salt of 4,4′-diamino-1,1′-dianthraquinonyl-3,3′-disulfonic acid. 相似文献
4.
Christian P. Klaus Carolin Thiemann Jürgen Kopf Paul Margaretha 《Helvetica chimica acta》1995,78(5):1079-1082
Irradiation (λ > 390 nm) of 2H-1-benzothiopyran-2-one ( 1 ) in the solid state affords selectively 6aα,6bα,12bα,12cα -tetrahydrocyclobuta[1,2-c:4,3-c′]bis[1]benzothiopyran -6,7-dione ( 2 ), the head-to-head (HH) cis-cisoid-cis-dimer, while irradiation of 1 in the solid state using shorter wavelengths (λ > 340 nm) affords a mixture of all four cis-fused tricyclic dimers 2 – 5 . These results represent a novel wavelength effect in solid-state photochemistry. 相似文献
5.
6.
7.
Dr. Peter Wick Dr. Anna E. Louw‐Gaume Dr. Melanie Kucki Prof. Harald F. Krug Prof. Kostas Kostarelos Prof. Bengt Fadeel Prof. Kenneth A. Dawson Dr. Anna Salvati Prof. Ester Vázquez Dr. Laura Ballerini Dr. Mauro Tretiach Dr. Fabio Benfenati Dr. Emmanuel Flahaut Dr. Laury Gauthier Prof. Maurizio Prato Dr. Alberto Bianco 《Angewandte Chemie (International ed. in English)》2014,53(30):7714-7718
8.
9.
10.
Xuan Thinh Duong Irina Holmes Ji Li Brett D. Wick Dongyong Yang 《Journal of Functional Analysis》2019,276(4):1007-1060
In this paper we establish the characterization of the weighted BMO via two weight commutators in the settings of the Neumann Laplacian on the upper half space and the reflection Neumann Laplacian on with respect to the weights associated to and respectively. This in turn yields a weak factorization for the corresponding weighted Hardy spaces, where in particular, the weighted class associated to is strictly larger than the Muckenhoupt weighted class and contains non-doubling weights. In our study, we also make contributions to the classical Muckenhoupt–Wheeden weighted Hardy space (BMO space respectively) by showing that it can be characterized via the area function (Carleson measure respectively) involving the semigroup generated by the Laplacian on and that the duality of these weighted Hardy and BMO spaces holds for Muckenhoupt weights with while the previously known related results cover only . We also point out that this two weight commutator theorem might not be true in the setting of general operators L, and in particular we show that it is not true when L is the Dirichlet Laplacian on . 相似文献