全文获取类型
收费全文 | 465092篇 |
免费 | 6843篇 |
国内免费 | 1225篇 |
专业分类
化学 | 248933篇 |
晶体学 | 5349篇 |
力学 | 19475篇 |
综合类 | 13篇 |
数学 | 56764篇 |
物理学 | 142626篇 |
出版年
2021年 | 3845篇 |
2020年 | 4655篇 |
2019年 | 4857篇 |
2018年 | 6293篇 |
2017年 | 6178篇 |
2016年 | 9835篇 |
2015年 | 6423篇 |
2014年 | 9486篇 |
2013年 | 22247篇 |
2012年 | 17239篇 |
2011年 | 21150篇 |
2010年 | 14489篇 |
2009年 | 14168篇 |
2008年 | 19404篇 |
2007年 | 19274篇 |
2006年 | 17834篇 |
2005年 | 15899篇 |
2004年 | 14604篇 |
2003年 | 12560篇 |
2002年 | 11566篇 |
2001年 | 13604篇 |
2000年 | 10022篇 |
1999年 | 7712篇 |
1998年 | 6355篇 |
1997年 | 6223篇 |
1996年 | 6100篇 |
1995年 | 5766篇 |
1994年 | 5743篇 |
1993年 | 5621篇 |
1992年 | 6174篇 |
1991年 | 6124篇 |
1990年 | 5907篇 |
1989年 | 5663篇 |
1988年 | 5704篇 |
1987年 | 5599篇 |
1986年 | 5270篇 |
1985年 | 6944篇 |
1984年 | 7092篇 |
1983年 | 5681篇 |
1982年 | 5768篇 |
1981年 | 5763篇 |
1980年 | 5291篇 |
1979年 | 5706篇 |
1978年 | 5877篇 |
1977年 | 5761篇 |
1976年 | 5650篇 |
1975年 | 5232篇 |
1974年 | 5168篇 |
1973年 | 5178篇 |
1972年 | 3587篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Satyanarayana A. V. S. Rao M. Jagannadha Mouli K. Chandra 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(3):1509-1513
Journal of Radioanalytical and Nuclear Chemistry - 相似文献
52.
Chromatographia - The present work deals with the optimization, validation and application of a versatile HPLC–DAD method for concurrent estimation of nine antimicrobials and proton pump... 相似文献
53.
Photo-catalytic elimination of organic contaminants plays a significant role in wastewater treatment. Developing a highly efficient photo-catalyst is one of the leading research topic. Herein, we reported the fabrication of a novel nanoporous NiO@SiO2 photo-catalyst by a simple ion-exchange method to eliminate the reactive dyes. The synthesized NiO@SiO2 catalyst exhibited fast photo-degradation and excellent adsorption capability and could efficiently remove Red FN-3GL dye from wastewater, due to a high loading of NiO and a large specific surface area, abundant electron-withdrawing groups, as well as narrow bandgap energy. In addition, the NiO@SiO2 photo-catalyst also displayed a high capability to remove reactive dyes over a wide range of pH values (pH 3–9). The prominent adsorption and photo-degradation of dyes were strongly dependent on the surface charge of the catalyst and the generation of hydroxyl radicals (OH?) by the catalyst, respectively. Furthermore, the NiO@SiO2 photo-catalyst also exhibited excellent recyclability, thus demonstrating the feasibility of practical applications in industries. The strategy of covering the metal oxide to nanoporous silica is a promising method for developing active photo-catalysts and applying them in the wastewater treatments. 相似文献
54.
Applied Mathematics and Mechanics - Mechanical models of residually stressed fibre-reinforced solids, which do not resist bending, have been developed in the literature. However, in some residually... 相似文献
55.
Hess Kristen M. Killgore Jason P. Mittal Ashutosh Srubar Wil V. 《Cellulose (London, England)》2022,29(10):5493-5509
Cellulose - Low-total-force contact resonance force microscopy (LTF-CRFM), an atomic force microscopy method, is introduced as a non-destructive means to quantify the local viscoelastic loss... 相似文献
56.
Premchand V. P. Balaram Bipin Mani Ajith K. Narayanan M. D. Sajith A. S. 《Nonlinear dynamics》2022,110(1):573-588
Nonlinear Dynamics - Optimisation procedures for nonlinear vibrating systems are made cumbersome due to the fact that the regimes of periodic response are not known beforehand. Moreover, such... 相似文献
57.
Radiophysics and Quantum Electronics - Under coupling, a large group of chaotic spiking–bursting oscillating neurons can undergo neuronal regularization. This aspect has been studied in... 相似文献
58.
Kovaleva V. V. Kuznetsov N. M. Vdovichenko A. Yu. Zagoskin Y. D. Grigoriev T. E. Chvalun S. N. 《Doklady Physical Chemistry》2022,502(2):23-27
Doklady Physical Chemistry - The rheological behavior of a 1 wt % suspension of highly porous chitosan particles in polydimethylsiloxane in a high electric field has been studied as a function of... 相似文献
59.
Turdybekov K. M. Nurkenov O. A. Seilkhanov T. M. Fazylov S. D. Turdybekova Ya. G. Kudusov A. S. 《Journal of Structural Chemistry》2022,63(6):944-950
Journal of Structural Chemistry - N-cyanomethylanabasine is prepared with an yield of 70% by the interaction of the alkaloid anabasine with glyconitrile. It is shown that the highest yield of the... 相似文献
60.
Reza Kordnezhadian Bing-Yu Li Armir Zogu Dr. Joachim Demaerel Prof. Dr. Wim M. De Borggraeve Dr. Ermal Ismalaj 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(60):e202201491
Pentafluorosulfanyl (SF5)-containing compounds and corresponding analogs are a highly valuable class of fluorine-containing building blocks owing to their unique properties. The reason for that is the set of peculiar and tremendously beneficial characteristics they can impart on molecules once introduced onto them. Despite this, their application in distinct scientific fields remains modest, given the extremely harsh reaction conditions needed to access such compounds. The recent synthetic approaches via S−F, and C−SF5 bond formation as well as the use of SF5-containing building blocks embody a “stairway-to-heaven” loophole in the synthesis of otherwise-inaccessible chemical scaffolds only a few years ago. Herein, we report and evaluate the properties of the SF5 group and analogs, by summarizing synthetic methodologies available to access them as well as following applications in material science and medicinal chemistry since 2015. 相似文献