全文获取类型
收费全文 | 363篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
化学 | 205篇 |
晶体学 | 3篇 |
力学 | 4篇 |
数学 | 37篇 |
物理学 | 135篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 12篇 |
2016年 | 13篇 |
2015年 | 13篇 |
2014年 | 12篇 |
2013年 | 21篇 |
2012年 | 24篇 |
2011年 | 21篇 |
2010年 | 8篇 |
2009年 | 23篇 |
2008年 | 18篇 |
2007年 | 14篇 |
2006年 | 19篇 |
2005年 | 10篇 |
2004年 | 15篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 5篇 |
1999年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1987年 | 2篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 9篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1969年 | 3篇 |
1963年 | 3篇 |
1939年 | 1篇 |
1938年 | 1篇 |
1937年 | 1篇 |
1932年 | 1篇 |
排序方式: 共有384条查询结果,搜索用时 31 毫秒
91.
Selective and controlled aerobic oxidation of activated benzyl alcohols to the corresponding aldehydes is achieved in refluxing CH3CN using catalytic amounts of MoO2Cl2(L)2 where L is DMSO, DMF or THF. The catalysis reactions are possible under open air in the absence of any other external co‐oxidants. However, bubbling of oxygen to the reaction mixture is useful in making the catalysis reaction sustained. Both activated and deactivated varieties of α‐substituted benzyl alcohols (secondary alcohols) give ketones in the same reaction conditions. The inexpensive catalyst is selective towards activated primary benzyl alcohols and also, being mild, stops the oxidation at the aldehyde stage, making it synthetically useful. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
92.
This paper considers the problem of finding limits for a statistical process control (SPC) chart for the process mean, when the process distribution is unknown. The bootstrap method estimates these limits relying on Monte Carlo methods, which are subject to simulation errors. Therefore this paper develops a computationally efficient enumeration method for exact calculations of the control limits. 相似文献
93.
Nagar V. Kar R. Pansare-Godambe L. Chand N. Bute A. Bhale D. Rao A. V. S. S. N. Shashidhar R. Maiti Namita 《Plasma Chemistry and Plasma Processing》2022,42(5):1115-1126
Plasma Chemistry and Plasma Processing - Traditional disinfection methods against pathogens have numerous shortcomings, and inventive methods like cold plasma are required for virus inactivation.... 相似文献
94.
JPC – Journal of Planar Chromatography – Modern TLC - The Ziziphus fruits are recognized as a rich source of biologically active compounds, such as polysaccharides, phenolics,... 相似文献
95.
Early-stage detection of diseases caused by pathogens is a prerequisite for expedient patient care. Due to the limited signal-to-noise ratio, molecular diagnostics needs molecular signal amplification after recognition of the target molecule. In this present study, we demonstrate the design of plasmonically coupled bimetallic Ag coated Au nanostar dimers with controlled nanogap using rectangular DNA origami. We further report the utility of the designed nanostar dimer structures as efficient SERS substrate for the ultrasensitive and label-free detection of the pyocyanin molecule, which is a biomarker of the opportunistic pathogenic bacteria, Pseudomonas aeruginosa. The experimental results showed that the detection limit of pyocyanin with such nanoantenna based biosensor was 335 pM, which is much lower than the clinical range of detection. Thus, fast, sensitive and label-free detection of pyocyanin at ultralow concentration in an infected human body can pave a facile route for early stage warning for severe bacterial infections. 相似文献
96.
Mehta Aarti Srivastava A. K. Gupta Govind Chand Suresh Sharma Shailesh Narain 《Journal of Sol-Gel Science and Technology》2021,99(2):295-314
Journal of Sol-Gel Science and Technology - In this article, the beneficial effect of surface passivation rendered by the amalgamation of co-ordinating tri-n-octylphophine (TOP), oleylamine (OLA),... 相似文献
97.
98.
Effect of 100 MeV O7+ ions irradiation on ethanol sensing response of nanostructures of ZnO and SnO2
Ravi Chand Singh Manmeet Pal Singh Onkar Singh Paramdeep Singh Chandi Ravi Kumar 《Applied Physics A: Materials Science & Processing》2010,98(1):161-166
Tin dioxide nanoparticles and zinc oxide nanorods were synthesized chemically and thick film gas sensors on alumina substrates
were fabricated of these materials. Morphology and crystallite size of synthesized powders were investigated by TEM. The fabricated
sensors were irradiated with 100 MeV O7+ ions at fluences of 1×1011, 1×1012 and 1×1013 ions/cm2. The X-ray diffraction analysis of the samples before and after ion bombardment was performed for structural characterization.
The sensing response to ethanol before and after irradiation was carried out for each fabricated sensor. Investigation revealed
that irradiated SnO2 based sensor’s response and response time increased significantly. Results show that ZnO based sensor exhibit strong resistance
to damage caused by ion irradiation which might be due to defects annihilation. 相似文献
99.
100.