全文获取类型
收费全文 | 346070篇 |
免费 | 4068篇 |
国内免费 | 1246篇 |
专业分类
化学 | 181040篇 |
晶体学 | 4718篇 |
力学 | 15870篇 |
综合类 | 11篇 |
数学 | 39021篇 |
物理学 | 110724篇 |
出版年
2021年 | 2578篇 |
2020年 | 2831篇 |
2019年 | 3097篇 |
2018年 | 3774篇 |
2017年 | 3729篇 |
2016年 | 5882篇 |
2015年 | 4031篇 |
2014年 | 5908篇 |
2013年 | 15969篇 |
2012年 | 12661篇 |
2011年 | 15466篇 |
2010年 | 10250篇 |
2009年 | 10306篇 |
2008年 | 14087篇 |
2007年 | 14165篇 |
2006年 | 13517篇 |
2005年 | 12221篇 |
2004年 | 11255篇 |
2003年 | 9854篇 |
2002年 | 9588篇 |
2001年 | 11118篇 |
2000年 | 8491篇 |
1999年 | 6607篇 |
1998年 | 5207篇 |
1997年 | 5229篇 |
1996年 | 4923篇 |
1995年 | 4484篇 |
1994年 | 4238篇 |
1993年 | 4052篇 |
1992年 | 4496篇 |
1991年 | 4474篇 |
1990年 | 4144篇 |
1989年 | 3983篇 |
1988年 | 4033篇 |
1987年 | 3982篇 |
1986年 | 3749篇 |
1985年 | 5237篇 |
1984年 | 5461篇 |
1983年 | 4398篇 |
1982年 | 4719篇 |
1981年 | 4594篇 |
1980年 | 4457篇 |
1979年 | 4490篇 |
1978年 | 4649篇 |
1977年 | 4640篇 |
1976年 | 4663篇 |
1975年 | 4437篇 |
1974年 | 4341篇 |
1973年 | 4489篇 |
1972年 | 2763篇 |
排序方式: 共有10000条查询结果,搜索用时 256 毫秒
101.
Ding Q. Yao M. Wu Sh. Zeng M. Xue N. Wu D. Xu J. 《Journal of Applied Spectroscopy》2022,89(4):712-718
Journal of Applied Spectroscopy - Based on partial least squares (PLS) analysis, the effects of different smoothing points and different preprocessing methods on the accuracy and precision of the... 相似文献
102.
Crystallography Reports - Nd1 – yEuyF3 – y crystals (y is the molar fraction of EuF2; 0 ≤ y ≤ 0.15) with a tysonite (LaF3) structure have... 相似文献
103.
Stolpovskaya N. V. Kruzhilin A. A. Zorina A. V. Shikhaliev Kh. S. Ledeneva I. V. Kosheleva E. A. Vandyshev D. Yu. 《Russian Journal of Organic Chemistry》2019,55(9):1322-1328
Russian Journal of Organic Chemistry - A procedure has been proposed for the synthesis of a series of substituted N-(1,3-thiazol-2-yl)-pyrimidin-2-amines and N-(pyrimidin-2-yl)thioureas by... 相似文献
104.
A protocol to correct for intra‐ and interspecific variation in tail hair growth to align isotope signatures of segmentally cut tail hair to a common time line 下载免费PDF全文
105.
106.
107.
108.
Francesco Segatta David M. Rogers Naomi T. Dyer Ellen E. Guest Zhuo Li Hainam Do Artur Nenov Marco Garavelli Jonathan D. Hirst 《Molecules (Basel, Switzerland)》2021,26(2)
A fully quantitative theory of the relationship between protein conformation and optical spectroscopy would facilitate deeper insights into biophysical and simulation studies of protein dynamics and folding. In contrast to intense bands in the far-ultraviolet, near-UV bands are much weaker and have been challenging to compute theoretically. We report some advances in the accuracy of calculations in the near-UV, which were realised through the consideration of the vibrational structure of the electronic transitions of aromatic side chains. 相似文献
109.
Corina Andronescu Justus Masa Richard D. Tilley John J. Gooding Wolfgang Schuhmann 《Current Opinion in Electrochemistry》2021
The complex interplay of restricted mass transport leading to local accumulation or depletion of educts, intermediates, products, counterions and co-ions influences the reactions at the active sites of electrocatalysts when electrodes are rough, three-dimensionally mesoporous or nanoporous. This influence is important with regard to activity, and even more to selectivity, of electrocatalytic reactions. The underlying principles are discussed based on the growing awareness of these considerations over recent years. 相似文献
110.
João Marcos G. Barbosa Milenna K. Fernandes Rodrigues Lurian C. David Taynara C. e Silva Danielly A. Fortuna Lima Naiara Z. Pereira Emmanuel B. D'Alessandro Anselmo E. de Oliveira Paulo H. Jorge da Cunha Maria Clorinda S. Fioravanti Nelson R. Antoniosi Filho 《Biomedical chromatography : BMC》2020,34(11):e4935
An innovative volatolomic approach employs the detection of biomarkers present in cerumen (earwax) to identify cattle intoxication by Stryphnodendron rotundifolium Mart., Fabaceae (popularly known as barbatimão). S. rotundifolium is a poisonous plant with the toxic compound undefined and widely distributed throughout the Brazilian territory. Cerumen samples from cattle of two local Brazilian breeds (‘Curraleiro Pé-Duro’ and ‘Pantaneiro’) were collected during an experimental intoxication protocol and analyzed using headspace (HS)/GC–MS followed by multivariate analysis (genetic algorithm for a partial least squares, cluster analysis, and classification and regression trees). A total of 106 volatile organic metabolites were identified in the cerumen samples of bovines. The intoxication by S. rotundifolium influenced the cerumen volatolomic profile of the bovines throughout the intoxication protocol. In this way, it was possible to detect biomarkers for cattle intoxication. Among the biomarkers, 2-octyldecanol and 9-tetradecen-1-ol were able to discriminate all samples between intoxicated and nonintoxicated bovines. The cattle intoxication diagnosis by S. rotundifolium was accomplished by applying the cerumen analysis using HS/GC–MS, in an easy, accurate, and noninvasive way. Thus, the proposed bioanalytical chromatography protocol is a useful tool in veterinary applications to determine this kind of intoxication. 相似文献