全文获取类型
收费全文 | 224672篇 |
免费 | 3454篇 |
国内免费 | 754篇 |
专业分类
化学 | 124663篇 |
晶体学 | 2374篇 |
力学 | 8670篇 |
综合类 | 9篇 |
数学 | 24512篇 |
物理学 | 68652篇 |
出版年
2018年 | 1746篇 |
2017年 | 1663篇 |
2016年 | 3274篇 |
2015年 | 2449篇 |
2014年 | 3240篇 |
2013年 | 9472篇 |
2012年 | 6858篇 |
2011年 | 8324篇 |
2010年 | 5558篇 |
2009年 | 5362篇 |
2008年 | 7611篇 |
2007年 | 7663篇 |
2006年 | 7358篇 |
2005年 | 6692篇 |
2004年 | 6092篇 |
2003年 | 5326篇 |
2002年 | 5133篇 |
2001年 | 6392篇 |
2000年 | 4966篇 |
1999年 | 3920篇 |
1998年 | 3080篇 |
1997年 | 3035篇 |
1996年 | 2889篇 |
1995年 | 2804篇 |
1994年 | 2724篇 |
1993年 | 2603篇 |
1992年 | 3134篇 |
1991年 | 2822篇 |
1990年 | 2785篇 |
1989年 | 2813篇 |
1988年 | 2722篇 |
1987年 | 2734篇 |
1986年 | 2544篇 |
1985年 | 3564篇 |
1984年 | 3551篇 |
1983年 | 2926篇 |
1982年 | 3104篇 |
1981年 | 3067篇 |
1980年 | 2955篇 |
1979年 | 3137篇 |
1978年 | 3371篇 |
1977年 | 3186篇 |
1976年 | 3099篇 |
1975年 | 2926篇 |
1974年 | 2871篇 |
1973年 | 2874篇 |
1972年 | 1834篇 |
1968年 | 2063篇 |
1967年 | 2314篇 |
1966年 | 2062篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
11.
Kacher Y. G. Karlova M. G. Glukhov G. S. Zhang H. Zaklyazminskaya E. V. Loussouarn G. Sokolova O. S. 《Crystallography Reports》2021,66(5):711-725
Crystallography Reports - Membrane proteins, including ion channels, became the focus of structural proteomics midway through the 20th century. Methods for studying ion channels are diverse and... 相似文献
12.
Kobayashi M. Zhang Y. Ishikawa H. Sun J. Oddershede J. Juul Jensen D. Miura H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such... 相似文献
13.
Alawainati F. A. Manaa H. Henari F. Z. Biyiklioglu Z. Arslan T. Jaafar A. 《Journal of Applied Spectroscopy》2021,88(5):951-957
Journal of Applied Spectroscopy - Detailed measurements of nonlinear optical properties and optical limiting for four phthalocyanine (Pc) derivatives (PcCo, PcCu, PcMn, and PcSi) are reported. The... 相似文献
14.
Analysis Mathematica - We introduce and study the k-Hankel Gabor transform. We investigate the localization operators for this transform. In particular, we study their trace class properties and we... 相似文献
15.
16.
Li Y. Shi W. H. Dong L. M. Xu S. X. Huang H. J. Yin J. R. 《Journal of Applied Spectroscopy》2022,89(3):534-541
Journal of Applied Spectroscopy - Sr3B2O6:Dy3+, Eu3+ single-matrix white-light-emitting materials are prepared using the high-temperature solid-state method. The microstructure, emission spectrum,... 相似文献
17.
Vasile M. Loots H. Vercammen L. Bruggeman M. Verrezen F. 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(8):3349-3357
Journal of Radioanalytical and Nuclear Chemistry - In this paper a study for the selection of an NPE (nonylphenol ethoxylates)—free cocktail is discussed in order to be used for our routine... 相似文献
18.
In this article we introduce a natural extension of the well-studied equation for harmonic maps between Riemannian manifolds by assuming that the target manifold is equipped with a connection that is metric but has non-vanishing torsion. Such connections have already been classified in the work of Cartan(1924).The maps under consideration do not arise as critical points of an energy functional leading to interesting mathematical challenges. We will perform a first mathematical analysis of these maps which we will call harmonic maps with torsion. 相似文献
19.
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