全文获取类型
收费全文 | 1786篇 |
免费 | 89篇 |
国内免费 | 147篇 |
专业分类
化学 | 324篇 |
晶体学 | 3篇 |
力学 | 151篇 |
综合类 | 70篇 |
数学 | 1111篇 |
物理学 | 363篇 |
出版年
2024年 | 2篇 |
2023年 | 18篇 |
2022年 | 58篇 |
2021年 | 53篇 |
2020年 | 53篇 |
2019年 | 53篇 |
2018年 | 52篇 |
2017年 | 58篇 |
2016年 | 58篇 |
2015年 | 44篇 |
2014年 | 42篇 |
2013年 | 155篇 |
2012年 | 62篇 |
2011年 | 71篇 |
2010年 | 53篇 |
2009年 | 80篇 |
2008年 | 114篇 |
2007年 | 109篇 |
2006年 | 97篇 |
2005年 | 112篇 |
2004年 | 62篇 |
2003年 | 85篇 |
2002年 | 87篇 |
2001年 | 63篇 |
2000年 | 39篇 |
1999年 | 52篇 |
1998年 | 48篇 |
1997年 | 39篇 |
1996年 | 30篇 |
1995年 | 23篇 |
1994年 | 18篇 |
1993年 | 17篇 |
1992年 | 14篇 |
1991年 | 13篇 |
1990年 | 4篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 2篇 |
排序方式: 共有2022条查询结果,搜索用时 171 毫秒
21.
22.
23.
We prove that simply connected open manifolds of bounded geometry, linear growth and sublinear filling growth (e.g. finite filling area) are simply connected at infinity. 相似文献
24.
Enrique Casanovas 《Mathematical Logic Quarterly》2003,49(5):475-478
We prove a property of generic homogeneity of tuples starting an infinite indiscernible sequence in a simple theory and we use it to give a shorter proof of the Independence Theorem for Lascar strong types. We also characterize the relation of starting an infinite indiscernible sequence in terms of coheirs. 相似文献
25.
Robert W. Baddeley Cheryl E. Praeger Csaba Schneider 《Transactions of the American Mathematical Society》2006,358(4):1619-1641
A permutation group is innately transitive if it has a transitive minimal normal subgroup, which is referred to as a plinth. We study the class of finite, innately transitive permutation groups that can be embedded into wreath products in product action. This investigation is carried out by observing that such a wreath product preserves a natural Cartesian decomposition of the underlying set. Previously we classified the possible embeddings in the case where the plinth is simple. Here we extend that classification and identify several different types of Cartesian decompositions that can be preserved by an innately transitive group with a non-abelian plinth. These different types of decompositions lead to different types of embeddings of the acting group into wreath products in product action. We also obtain a full characterisation of embeddings of innately transitive groups with diagonal type into such wreath products.
26.
本文给出了一种方法用于构造k-紧优双环网络无限族(k≥1),并用此方法构造出了4族3-紧优无限族,3族新的4-紧比无限族,3族5-紧优无限族及2族6-紧优无限族. 相似文献
27.
28.
A stochastic method of optimization, which combines simulated annealing with simplex, is implemented to fit the parameters of a simple model potential. The main characteristic of the method is that it explores the whole space of the parameters of the model potential, and therefore it is very efficient in locating the global minimum of the cost function, in addition to being independent of the initial guess of the parameters. The method is employed to fit the complex intermolecular potential energy surface of the dimer of water, using as a reference the spectroscopic quality anisotropic site-site potential of Feller et al. The simple model potential chosen for its reparameterization is the MCY model potential of Clementi et al. The quality of the fit is assessed by comparing the geometry of the minimum, the harmonic frequencies, and the second virial coefficients of the parameterized potential with the reference one. Finally, to prove more rigorously the robustness of this method, it is compared with standard nonstochastic methods of optimization. 相似文献
29.
以“探究水的组成”教学为例,通过课标、教材及学习者分析,从认识角度、探究水平、认识水平等3个维度整体规划“身边的化学物质”主题单元目标学习进阶,明确“探究水的组成”课时目标,通过温故建模、据模探究、探究推理等3个阶段的教学实施,建立具体物质的研究思路模型,运用模型研究陌生物质(氢气),初步形成定量研究物质组成的能力。 相似文献
30.
Changjun Peng Shouhong Xu Hongze Gang Tianxiang Yin Jun Hu Yazhuo Shang Honglai Liu Encheng Hei 《大学化学》1986,36(1):2006013-0
As a necessary basic theory course for undergraduates majoring in chemistry, materials, pharmacy, chemical engineering, and biology, physical chemistry plays an important role in cultivating talents to meet the needs of social and economic development. Over the years, the teaching team of physical chemistry of East China University of Science and Technology has carried out the curriculum reform and innovation persistently based on "Team building as the foundation, resource building as the root, mode innovation as the soul, ability training as the origin". This paper will summarize our thinking and experience in striving for the first-class course from the aspects of first-class team construction, first-class resource construction, teaching connotation innovation, teaching mode exploration, and extract the experience that can be used as reference by teaching peers. 相似文献