全文获取类型
收费全文 | 384757篇 |
免费 | 6815篇 |
国内免费 | 3359篇 |
专业分类
化学 | 195106篇 |
晶体学 | 6167篇 |
力学 | 18881篇 |
综合类 | 164篇 |
数学 | 44191篇 |
物理学 | 130422篇 |
出版年
2022年 | 3267篇 |
2021年 | 4063篇 |
2020年 | 4271篇 |
2019年 | 4774篇 |
2018年 | 6133篇 |
2017年 | 6302篇 |
2016年 | 8762篇 |
2015年 | 5382篇 |
2014年 | 8646篇 |
2013年 | 18807篇 |
2012年 | 15315篇 |
2011年 | 18253篇 |
2010年 | 13444篇 |
2009年 | 13409篇 |
2008年 | 16074篇 |
2007年 | 15768篇 |
2006年 | 14531篇 |
2005年 | 12569篇 |
2004年 | 11635篇 |
2003年 | 10269篇 |
2002年 | 10254篇 |
2001年 | 12650篇 |
2000年 | 9389篇 |
1999年 | 7322篇 |
1998年 | 5963篇 |
1997年 | 5779篇 |
1996年 | 5288篇 |
1995年 | 4584篇 |
1994年 | 4485篇 |
1993年 | 4295篇 |
1992年 | 4859篇 |
1991年 | 5054篇 |
1990年 | 4772篇 |
1989年 | 4605篇 |
1988年 | 4366篇 |
1987年 | 4522篇 |
1986年 | 4164篇 |
1985年 | 5306篇 |
1984年 | 5301篇 |
1983年 | 4314篇 |
1982年 | 4417篇 |
1981年 | 4115篇 |
1980年 | 4029篇 |
1979年 | 4363篇 |
1978年 | 4390篇 |
1977年 | 4425篇 |
1976年 | 4327篇 |
1975年 | 4045篇 |
1974年 | 4001篇 |
1973年 | 3978篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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62.
Russian Journal of Applied Chemistry - Quenching method was used to obtain glasses in the system xWO3-(100-x)P2O5 (x = 70, 75, 80, 82 mol %). The electrical conductivity of the compositions was... 相似文献
63.
Doklady Mathematics - An Erratum to this paper has been published: https://doi.org/10.1134/S1064562421330012 相似文献
64.
Mohammad Azam Saud I. Al-Resayes Agata Trzesowska-Kruszynska Rafal Kruszynski S.F. Adil N.K. Lokanath 《Journal of Saudi Chemical Society》2019,23(5):636-641
A new derivative of dioxouranium(VI) salen complex, [UO2(L)(pyridine)], where [L = N,N′-Bis(2-hydroxybenzylidene)-2,2-dimethyl-1,3-propanediamine] is synthesized and characterized by elemental analysis (C, H, N), FT-IR, ESI-MS spectrometry, UV/Vis, fluorescence, 1H and 13C NMR spectroscopy and thermal gravimetric (TG) study. Furthermore, the single crystal X-ray diffraction measurements of the complex were carried out at 100 and 273 K. The crystal structure measurements revealed that the complex has distorted pentagonal bipyramidal geometry with uranium atom located at the centre and bonded to two phenoxy oxygen and two azomethine nitrogen in tetradenate fashion and one nitrogen from pyridine making it seven coordinated. In addition, the photoluminescence property of the complex was also recorded. 相似文献
65.
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
66.
67.
Saleh Z. M. Nasser H. Özkol E. Günöven M. Abak K. Canli S. Bek A. Turan R. 《Journal of nanoparticle research》2015,17(10):1-12
Journal of Nanoparticle Research - Plasmonic interfaces consisting of silver nanoparticles of different sizes (50–100&;nbsp;nm) have been processed by the self-assembled dewetting... 相似文献
68.
69.
Triazines are widely used in agriculture around the world as selective pre‐ and post‐emergence herbicides for the control of broad leaf and grassy weeds. With high toxicity and persistence, triazines can contaminate the environment and crops, so the development of rapid and sensitive methods for the determination of different triazines is necessary. Capillary electrophoresis comprises a group of techniques used to separate chemical mixtures. Analytical separation is based on different electrophoretic mobilities. This review focuses on the analysis of triazine herbicides with different modes of capillary electrophoresis, including capillary zone electrophoresis, micellar electrokinetic capillary electrophoresis, capillary electrochromatography and nonaqueous capillary electrophoresis. Determinations of triazines in various matrices such as surface water, groundwater, vegetables, soil and grains are emphasized. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
70.