全文获取类型
收费全文 | 1963篇 |
免费 | 228篇 |
国内免费 | 382篇 |
专业分类
化学 | 1295篇 |
晶体学 | 58篇 |
力学 | 144篇 |
综合类 | 30篇 |
数学 | 299篇 |
物理学 | 747篇 |
出版年
2024年 | 1篇 |
2023年 | 85篇 |
2022年 | 79篇 |
2021年 | 110篇 |
2020年 | 115篇 |
2019年 | 62篇 |
2018年 | 61篇 |
2017年 | 81篇 |
2016年 | 65篇 |
2015年 | 84篇 |
2014年 | 98篇 |
2013年 | 137篇 |
2012年 | 174篇 |
2011年 | 185篇 |
2010年 | 161篇 |
2009年 | 156篇 |
2008年 | 100篇 |
2007年 | 157篇 |
2006年 | 138篇 |
2005年 | 71篇 |
2004年 | 54篇 |
2003年 | 38篇 |
2002年 | 39篇 |
2001年 | 55篇 |
2000年 | 40篇 |
1999年 | 43篇 |
1998年 | 34篇 |
1997年 | 33篇 |
1996年 | 22篇 |
1995年 | 28篇 |
1994年 | 15篇 |
1993年 | 10篇 |
1992年 | 15篇 |
1991年 | 14篇 |
1990年 | 6篇 |
1985年 | 6篇 |
1957年 | 1篇 |
排序方式: 共有2573条查询结果,搜索用时 31 毫秒
1.
2.
Acta Mathematica Sinica, English Series - We are interested in the existence and asymptotic behavior for the least energy solutions of the following fractional eigenvalue problem $$\left({\rm{P}}... 相似文献
3.
Considering the significant importance in both ecological and environmental fields, converting nitrogen oxide(NOx, especially NO) into value-added NH3or harmless N2lies in the core of research over the past decades. Exploring catalyst for related gas molecular activation and highly efficient reaction systems operated under low temperature or even mild conditions are the key issues. Enormous efforts have been devoted to NO removal by utilizing various driving forces, such as thermal, electrical o... 相似文献
4.
对硫化镉反蛋白石结构光子晶体薄膜进行了可控合成,用巯基乙酸修饰的纳米晶和P(St-MMA-SPMAP)高分子小球共组装,成功地构筑了反蛋白石结构并用于可见光光解水产氢。结果表明,在可见光(λ≥420 nm)照射下,Cd S-310反蛋白石结构薄膜的光解水产氢性能比硫化镉纳米颗粒提高了一倍。这主要是因为等级孔结构反蛋白石光子晶体特性对催化剂的光催化性能的提升:首先,反蛋白石的周期性结构增加了光子在材料中的传播,提高了催化剂对太阳光的利用率;同时,大孔孔壁是由纳米颗粒堆积而成的,在反应中提供了更多的反应活性位点;此外,孔结构有利于物质的传输和分子的吸附。 相似文献
5.
Ding Wenwen He Yongjia Lu Linnu Rao Meijuan Wang Fazhou 《Journal of Thermal Analysis and Calorimetry》2019,135(4):2009-2018
Journal of Thermal Analysis and Calorimetry - The present task is to investigate the influence of iron on the mineral composition and microstructure of the phase Q (C20A13M3S3, in the text below... 相似文献
6.
We study ground states of two-component Bose–Einstein condensates (BEC) with trapping potentials in , where the intraspecies interaction and the interspecies interaction ?β are both attractive, , , and β are all positive. The existence and non-existence of ground states are classified completely by investigating equivalently the associated -critical constraint variational problem. The uniqueness and symmetry-breaking of ground states are also analyzed under different types of trapping potentials as , where () is fixed and w is the unique positive solution of in . The semi-trivial limit behavior of ground states is tackled in the companion paper [12]. 相似文献
7.
8.
In this article,we study the initial boundary value problem of coupled semi-linear degenerate parabolic equations with a singular potential term on manifolds with corner singularities.Firstly,we introduce the corner type weighted p-Sobolev spaces and the weighted corner type Sobolev inequality,the Poincare′inequality,and the Hardy inequality.Then,by using the potential well method and the inequality mentioned above,we obtain an existence theorem of global solutions with exponential decay and show the blow-up in finite time of solutions for both cases with low initial energy and critical initial energy.Significantly,the relation between the above two phenomena is derived as a sharp condition.Moreover,we show that the global existence also holds for the case of a potential well family. 相似文献
9.
《Indagationes Mathematicae》2022,33(4):801-815
We consider the irreducibility of polynomial where is a negative integer. We observe that the constant term of vanishes if and only if . Therefore we assume that where is a non-negative integer. Let and more general polynomial, let where with are integers such that . Schur was the first to prove the irreducibility of for . It has been proved that is irreducible for . In this paper, by a different method, we prove: Apart from finitely many explicitly given possibilities, either is irreducible or is linear factor times irreducible polynomial. This is a consequence of the estimate whenever has a factor of degree and . This sharpens earlier estimates of Shorey and Tijdeman and Nair and Shorey. 相似文献
10.
Proteins play a central role in all domains of life, and precise regulation of their activity is essential for understanding the related biological processes and therapeutic functions. Nucleic acid aptamers, the molecular recognition components derived from systematic evolution of ligands by exponential enrichment(SELEX), can specifically identify proteins with antibody-like recognition characteristics and help to regulate their activity. This minireview covers the SELEX-based selection of protein-binding aptamers, membrane protein analytical techniques based on aptamer-mediated target recognition, aptamer-mediated functional regulation of proteins, including membrane receptors and non-membrane proteins(thrombin as a model), as well as the potential challenges and prospects regarding aptamer-mediated protein manipulation, aiming to supply some useful information for researchers in this field. 相似文献