全文获取类型
收费全文 | 7303篇 |
免费 | 160篇 |
国内免费 | 2篇 |
专业分类
化学 | 4086篇 |
晶体学 | 136篇 |
力学 | 152篇 |
数学 | 1125篇 |
物理学 | 1966篇 |
出版年
2022年 | 31篇 |
2021年 | 134篇 |
2020年 | 103篇 |
2019年 | 135篇 |
2018年 | 135篇 |
2017年 | 136篇 |
2016年 | 234篇 |
2015年 | 184篇 |
2014年 | 258篇 |
2013年 | 610篇 |
2012年 | 363篇 |
2011年 | 411篇 |
2010年 | 329篇 |
2009年 | 299篇 |
2008年 | 340篇 |
2007年 | 332篇 |
2006年 | 289篇 |
2005年 | 235篇 |
2004年 | 219篇 |
2003年 | 220篇 |
2002年 | 165篇 |
2001年 | 139篇 |
2000年 | 127篇 |
1999年 | 94篇 |
1998年 | 99篇 |
1997年 | 71篇 |
1996年 | 74篇 |
1995年 | 97篇 |
1994年 | 57篇 |
1993年 | 42篇 |
1992年 | 71篇 |
1991年 | 45篇 |
1990年 | 64篇 |
1989年 | 57篇 |
1988年 | 71篇 |
1987年 | 54篇 |
1986年 | 62篇 |
1985年 | 96篇 |
1984年 | 106篇 |
1983年 | 67篇 |
1982年 | 63篇 |
1981年 | 67篇 |
1980年 | 83篇 |
1979年 | 56篇 |
1978年 | 63篇 |
1977年 | 66篇 |
1976年 | 66篇 |
1975年 | 51篇 |
1974年 | 46篇 |
1973年 | 43篇 |
排序方式: 共有7465条查询结果,搜索用时 46 毫秒
1.
Dariusz Marek Adam Domaski Joanna Domaska Jakub Szygua Tadeusz Czachrski Jerzy Klamka 《Entropy (Basel, Switzerland)》2021,23(5)
In this article, a way to employ the diffusion approximation to model interplay between TCP and UDP flows is presented. In order to control traffic congestion, an environment of IP routers applying AQM (Active Queue Management) algorithms has been introduced. Furthermore, the impact of the fractional controller and its parameters on the transport protocols is investigated. The controller has been elaborated in accordance with the control theory. The TCP and UDP flows are transmitted simultaneously and are mutually independent. Only the TCP is controlled by the AQM algorithm. Our diffusion model allows a single TCP or UDP flow to start or end at any time, which distinguishes it from those previously described in the literature. 相似文献
2.
Gürbüzbalaban Mert Ruszczyński Andrzej Zhu Landi 《Journal of Optimization Theory and Applications》2022,194(3):1014-1041
Journal of Optimization Theory and Applications - We consider a distributionally robust formulation of stochastic optimization problems arising in statistical learning, where robustness is with... 相似文献
3.
Journal of Solid State Electrochemistry - A methodology for electrochemical preparation of nickel layers intended to be used as targets for charged particle accelerators is proposed. The goal is to... 相似文献
4.
5.
Michnik Anna Kiełboń Agnieszka Duch Klaudia Sadowska-Krępa Ewa Pokora Ilona 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6739-6743
Journal of Thermal Analysis and Calorimetry - The results of studies of physiological fluids by differential scanning calorimetry (DSC) for the purpose of diagnosis and monitoring of diseases are... 相似文献
6.
Jakub Trawiński 《液相色谱法及相关技术杂志》2019,42(3-4):63-73
Photostability of an antidepressant agomelatine under the simulated solar radiation was studied. Quantitative and qualitative analysis of this process was performed with the use of UHPLC-DAD system coupled with a high resolution hybrid ESI-Q-TOF mass spectrometer. In contrast to the foregoing studies agomelatine turned out to be relatively photolabile compound. During the experiment six transformation products were formed, and their structures were elucidated on the basis of MS/MS fragmentation spectra. Four of these photoproducts were found to be a result of aromatic and aliphatic hydroxylation. Additionally, identified products were submitted to the in silico toxicity evaluation, which showed that some of them could be more mutagenic or toxic to rodents than the parent compound. 相似文献
7.
8.
9.
10.