全文获取类型
收费全文 | 4264篇 |
免费 | 290篇 |
国内免费 | 275篇 |
专业分类
化学 | 448篇 |
晶体学 | 2篇 |
力学 | 394篇 |
综合类 | 42篇 |
数学 | 2710篇 |
物理学 | 1233篇 |
出版年
2024年 | 13篇 |
2023年 | 34篇 |
2022年 | 45篇 |
2021年 | 68篇 |
2020年 | 101篇 |
2019年 | 109篇 |
2018年 | 97篇 |
2017年 | 98篇 |
2016年 | 94篇 |
2015年 | 94篇 |
2014年 | 157篇 |
2013年 | 317篇 |
2012年 | 167篇 |
2011年 | 207篇 |
2010年 | 148篇 |
2009年 | 253篇 |
2008年 | 260篇 |
2007年 | 253篇 |
2006年 | 228篇 |
2005年 | 204篇 |
2004年 | 186篇 |
2003年 | 195篇 |
2002年 | 185篇 |
2001年 | 143篇 |
2000年 | 133篇 |
1999年 | 128篇 |
1998年 | 117篇 |
1997年 | 95篇 |
1996年 | 84篇 |
1995年 | 66篇 |
1994年 | 65篇 |
1993年 | 49篇 |
1992年 | 42篇 |
1991年 | 40篇 |
1990年 | 34篇 |
1989年 | 41篇 |
1988年 | 27篇 |
1987年 | 19篇 |
1986年 | 20篇 |
1985年 | 28篇 |
1984年 | 30篇 |
1983年 | 19篇 |
1982年 | 23篇 |
1981年 | 17篇 |
1980年 | 10篇 |
1979年 | 26篇 |
1978年 | 15篇 |
1977年 | 14篇 |
1976年 | 10篇 |
1973年 | 6篇 |
排序方式: 共有4829条查询结果,搜索用时 16 毫秒
1.
Thalia Tsiaka Panagiotis Zoumpoulakis Vassilia J. Sinanoglou Constantinos Makris Georgios A. Heropoulos Antony C. Calokerinos 《Analytica chimica acta》2015
High-energy assisted extraction techniques, like ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE), are widely applied over the last years for the recovery of bioactive compounds such as carotenoids, antioxidants and phenols from foods, animals and herbal natural sources. Especially for the case of xanthophylls, the main carotenoid group of crustaceans, they can be extracted in a rapid and quantitative way with the use of UAE and MAE. 相似文献
2.
《Indagationes Mathematicae》2022,33(1):218-237
We define the notion of basic set data for finite groups (building on the notion of basic set, but including an order on the irreducible characters as part of the structure), and we prove that the Springer correspondence provides basic set data for Weyl groups. Then we use this to determine explicitly the modular Springer correspondence for classical types (defined over a base field of odd characteristic , and with coefficients in a field of odd characteristic ): the modular case is obtained as a restriction of the ordinary case to a basic set. In order to do so, we compare the order on bipartitions introduced by Dipper and James with the order induced by the Springer correspondence. We provide a quick proof, by sorting characters according to the dimension of the corresponding Springer fibre, an invariant which is directly computable from symbols. 相似文献
3.
ABSTRACT A new density functional for the study of associating inhomogeneous fluids based on Wertheim's first-order thermodynamic perturbation theory is presented and compared to the most currently used associating density functionals. This functional is developed using the weighted density approximation in the range of association of hard spheres. We implement this functional within the framework of classical density functional theory together with modified fundamental measure theory to account for volume exclusion of hard spheres. This approach is tested against molecular simulations from literature of pure associating hard spheres and mixtures of non-associationg and associating hard spheres with different number of bonding sites close to a hard uniform wall. Furthermore, we compare and review our results with the performance of associating functionals from literature, one based on fundamental measure theory and the inhomogeneous version of Wertheim's perturbation theory. Results obtained with classical DFT and the three functionals show excellent agreement with molecular simulations in systems with one hard wall. For the cases of small pores where only one or two layers of fluid are allowed discrepancies between results with classical DFT and molecular simulations were found. 相似文献
4.
The zero dissipation limit of the one-dimensional non-isentropic micropolar equations is studied in this paper. If the given rarefaction wave which connects to vacuum at one side, a sequence of solution to the micropolar equations can be constructed which converge to the above rarefaction wave with vacuum as the viscosity and the heat conduction coefficient tend to zero. Moreover, the uniform convergence rate is obtained. The key point in our analysis is how to control the degeneracies in the vacuum region in the zero dissipation limit process. 相似文献
5.
6.
7.
Jeannette H. C. Woerner 《商业与工业应用随机模型》2005,21(1):27-44
In the framework of stochastic volatility models we examine estimators for the integrated volatility based on the pth power variation (i.e. the sum of pth absolute powers of the log‐returns). We derive consistency and distributional results for the estimators given high‐frequency data, especially taking into account what kind of process we may add to our model without affecting the estimate of the integrated volatility. This may on the one hand be interpreted as a possible flexibility in modelling, for example adding jumps or even leaving the framework of semimartingales by adding a fractional Brownian motion, or on the other hand as robustness against model misspecification. We will discuss possible choices of p under different model assumptions and irregularly spaced data. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
8.
Philippe Bénilan 《Journal of Differential Equations》2004,196(2):301-315
In this paper, we study the singular limit of the Porous Medium equation ut=Δum+g(x,u), as m→∞, in a bounded domain with Neumann boundary condition. 相似文献
9.
Miklós Csörgő 《Periodica Mathematica Hungarica》2005,50(1-2):1-27
Summary This article provides a glimpse of some of the highlights of the joint work of Endre Csáki and Pál Révész since 1979. The topics of this short exploration of the rich stochastic milieu of this inspiring collaboration revolve around Brownian motion, random walks and their long excursions, local times and additive functionals, iterated processes, almost sure local and global central limit theorems, integral functionals of geometric stochastic processes, favourite sites--favourite values and jump sizes for random walk and Brownian motion, random walking in a random scenery, and large void zones and occupation times for coalescing random walks. 相似文献
10.
林正炎 《数学物理学报(B辑英文版)》2003,23(3)
Let {X_n, n≥1} be a strictly stationary sequence of random variables, whichare either associated or negatively associated, f(·) be their common density. In this paper,the author shows a central limit theorem for a kernel estimate of f(·) under certain regularconditions. 相似文献