全文获取类型
收费全文 | 350544篇 |
免费 | 4398篇 |
国内免费 | 3252篇 |
专业分类
化学 | 159644篇 |
晶体学 | 4105篇 |
力学 | 19934篇 |
综合类 | 80篇 |
数学 | 71056篇 |
物理学 | 103375篇 |
出版年
2021年 | 1437篇 |
2020年 | 1730篇 |
2019年 | 1746篇 |
2018年 | 18697篇 |
2017年 | 19378篇 |
2016年 | 12043篇 |
2015年 | 4378篇 |
2014年 | 3910篇 |
2013年 | 10071篇 |
2012年 | 15554篇 |
2011年 | 30389篇 |
2010年 | 17814篇 |
2009年 | 18407篇 |
2008年 | 24400篇 |
2007年 | 29359篇 |
2006年 | 8756篇 |
2005年 | 16136篇 |
2004年 | 12211篇 |
2003年 | 11082篇 |
2002年 | 7716篇 |
2001年 | 6589篇 |
2000年 | 5110篇 |
1999年 | 3609篇 |
1998年 | 2784篇 |
1997年 | 2732篇 |
1996年 | 2847篇 |
1995年 | 2564篇 |
1994年 | 2412篇 |
1993年 | 2319篇 |
1992年 | 2556篇 |
1991年 | 2472篇 |
1990年 | 2180篇 |
1989年 | 2142篇 |
1988年 | 2200篇 |
1987年 | 2124篇 |
1986年 | 2012篇 |
1985年 | 2990篇 |
1984年 | 2971篇 |
1983年 | 2376篇 |
1982年 | 2543篇 |
1981年 | 2429篇 |
1980年 | 2392篇 |
1979年 | 2325篇 |
1978年 | 2412篇 |
1977年 | 2271篇 |
1976年 | 2226篇 |
1975年 | 2202篇 |
1974年 | 2103篇 |
1973年 | 2210篇 |
1972年 | 1248篇 |
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
1.
Zlámalová M. Pitňa Lásková B. Vinarčíková M. Zukalová M. Kavan L. 《Journal of Solid State Electrochemistry》2022,26(3):639-647
Journal of Solid State Electrochemistry - The addition of nanocrystalline titanium dioxide (P90) to a cathode of Li/S cell enhances its voltammetric charge capacity by 19%, from which only a small... 相似文献
2.
Fernández Julio R. Gallego Inés Jiménez-Losada Andrés Ordóñez Manuel 《Fuzzy Optimization and Decision Making》2022,21(4):531-551
Fuzzy Optimization and Decision Making - Cost-allocation problems in a fixed network are concerned with distributing the costs for use by a group of clients who cooperate in order to reduce such... 相似文献
3.
Numerical Algorithms - An inverse central ordering of the nodes is proposed for the Newton interpolation formula. This ordering may improve the stability for certain distributions of nodes. For... 相似文献
4.
Atopic dermatitis is characterized by leukocyte migration into the skin dermis and typically driven by excessive chemokine production at the site of inflammation. Conventional topical formulations such as gels, creams, and ointments are insufficient for this treatment because of low penetration of drug molecules into the targeted skin tissues. Herein, using a simple, green, sustainable strategy, we have developed novel primary zein nanoparticles embedded in curcumin (Cur) and coated with silk sericin (ZHSCs) for the topical delivery of Cur to penetrate into the dermis and exercise anti-dermatitis effects on the lesion with minimal side-effects. Transdermal delivery experiments and porcine skin fluorescence imaging indicated that ZHSCs facilitate the penetration of Cur across the epidermis layer of skin to reach deep-seated sites. Notably, ZHSCs = 1:0.25 (zein-to-silk sericin mass ratios of 1:0.25) markedly elevated the skin permeability and cumulative turnover of Cur transferred, which were provided a greater than a 3.8-fold increase relative to free Cur. The special nanoparticles of ZHS = 1:0.25 possessed the deepest localization depth and experience a transition of the particle structure and core-shell separation after penetrating into the dermis of skin. In a cell model of dermatitis induced by tumor necrosis factor α/interferon γ co-stimulation, compared with free Cur, Cur-loaded ZHS nanoparticles down-regulated the generation of inflammatory cytokines and chemokines in keratinocytes through suppression of the nuclear translocation of NF-κBp65 and hence exerted an anti-dermatitis effect. This strategy may provide new avenues and direction for the demanding issues of valid topical delivery systems. 相似文献
5.
6.
Journal of Analytical Chemistry - The review considers the historical aspects of the formation and development of bioelectrochemistry and some issues of the analytical application of... 相似文献
7.
Garcia-Vicua Daniel Esparza Laida Mallor Fermin 《Central European Journal of Operations Research》2022,30(1):213-249
Central European Journal of Operations Research - This paper presents a discrete event simulation model to support decision-making for the short-term planning of hospital resource needs, especially... 相似文献
8.
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
9.
10.
A model with 16 moments is here presented in the framework of RET of polyatomic gases. It furnishes as principal subsystem the relativistic counterpart of a work by Arima T., Ruggeri T., Sugiyama M.; this is present in literature and treats the non relativistic case which incorporates relaxation processes of molecular rotation and vibration. Another principal subsystem is the natural extension of the 14 moments model by Pennisi S. and Ruggeri T.; this is also present in literature in the relativistic framework but where the trace of the third balance equation is neglected. Its extension is found here for the case when this trace isn’t neglected.
相似文献