全文获取类型
收费全文 | 234篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学 | 164篇 |
力学 | 6篇 |
数学 | 18篇 |
物理学 | 48篇 |
出版年
2019年 | 1篇 |
2016年 | 2篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 8篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 15篇 |
2008年 | 10篇 |
2007年 | 17篇 |
2006年 | 11篇 |
2005年 | 9篇 |
2004年 | 16篇 |
2003年 | 15篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有236条查询结果,搜索用时 250 毫秒
41.
Tadakatsu Mandai Masashi Yamaguchi Yuka Nakayama Junzo Otera Mikio Kawada 《Tetrahedron letters》1985,26(22):2675-2676
Development of a new synthetic method for α-ketosilanes can be achieved by a sequence of alkylation of methoxy(phenylthio)trialkylsilylmethane and oxidation with NaIO4. 相似文献
42.
43.
44.
Juan Migliore Rosa M. Miró-Roig Satoshi Murai Uwe Nagel Junzo Watanabe 《Archiv der Mathematik》2013,101(5):445-454
A homogeneous ideal I of a polynomial ring S is said to have the Rees property if, for any homogeneous ideal ${J \subset S}$ which contains I, the number of generators of J is smaller than or equal to that of I. A homogeneous ideal ${I \subset S}$ is said to be ${\mathfrak{m}}$ -full if ${\mathfrak{m}I:y=I}$ for some ${y \in \mathfrak{m}}$ , where ${\mathfrak{m}}$ is the graded maximal ideal of ${S}$ . It was proved by one of the authors that ${\mathfrak{m}}$ -full ideals have the Rees property and that the converse holds in a polynomial ring with two variables. In this note, we give examples of ideals which have the Rees property but are not ${\mathfrak{m}}$ -full in a polynomial ring with more than two variables. To prove this result, we also show that every Artinian monomial almost complete intersection in three variables has the Sperner property. 相似文献
45.
Goto A Endo K Ukai Y Irle S Saito S 《Chemical communications (Cambridge, England)》2008,(19):2212-2214
An aldol-type reaction of organonitriles with aldehydes was catalyzed by a RhI(OR) species under ambient conditions, and the reaction displayed a broad substrate scope with respect to both organonitrile and aldehyde components. 相似文献
46.
In this study, we establish a bilevel electricity trading model where fuzzy set theory is applied to address future load uncertainty, system reliability as well as human imprecise knowledge. From the literature, there have been some studies focused on this bilevel problem while few of them consider future load uncertainty and unit commitment optimization which handles the collaboration of generation units. Then, our study makes the following contributions: First, the future load uncertainty is characterized by fuzzy set theory, as the various factors that affect the load forecasting are often assessed with some non-statistical uncertainties. Second, the generation costs are obtained by solving complicated unit commitment problems, rather than approximate calculations used in existing studies. Third, this model copes with the optimizations of both the generation companies and the market operator, where the unexpected load risk is particularly analyzed by using fuzzy value-at-risk as a quantitative risk measurement. Forth, a mechanism to encourage the convergence of the bilevel model is proposed based on fuzzy maxmin approach, and a bilevel particle swarm optimization algorithm is developed to solve the problem in a proper runtime. To illustrate the effectiveness of this research, we provide a test system-based numerical example and discuss about the experimental results according to the principle of social welfare maximization. Finally, we also compare the model and algorithm with conventional methods. 相似文献
47.
Let A be a standard graded Artinian K-algebra, with char K=0. We prove the following.
- 1.
- A has the Weak Lefschetz Property (resp. Strong Lefschetz Property) if and only if has the Weak Lefschetz Property (resp. Strong Lefschetz Property) for some linear form z of A.
- 2.
- If A is Gorenstein, then A has the Strong Lefschetz Property if and only if there exists a linear form z of A such that all central simple modules of (A,z) have the Strong Lefschetz Property.
48.
Relocation of a glycosylphosphatidylinositol (GPI)-anchored protein acetylcholinesterase (AChE) in its enzymatically active form from proteovesicles containing human erythrocyte ghost membrane proteins onto a liposome-gel conjugate was examined. Liposomes of 1,2-dimyristoylphosphatidylcholine (DMPC) were immobilized on Sephacryl S-1000 gel that was chemically modified to bear hydrophobic octyl moieties. Upon coincubation of the liposome-gel conjugate with freely suspended proteovesicles prepared from erythrocyte ghosts, 50% of the AChE left the proteovesicles and immobilized onto the liposome-gel conjugate in 18 h. When the proteovesicles were immobilized and interacted with freely suspended plain liposomes, approximately 2% of the AChE appeared in the liposome fraction. The relocation of AChE apparently possesses strong preference for the liposome-gel conjugate, suggesting that the hydrophobic moieties on the gel could assist the relocation. 相似文献
49.
50.
De Lie An Qiang Chen Hong Yan Nobuaki Miura Kenji Monde Junzo Otera 《Tetrahedron letters》2009,50(15):1689-1692
Stereochemical study of cyclophynes, which is otherwise rather difficult to perform, can be achieved by vibrational CD spectroscopy. 相似文献