全文获取类型
收费全文 | 139篇 |
免费 | 5篇 |
专业分类
化学 | 101篇 |
晶体学 | 3篇 |
力学 | 1篇 |
数学 | 4篇 |
物理学 | 31篇 |
无线电 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 19篇 |
2012年 | 4篇 |
2011年 | 5篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有144条查询结果,搜索用时 4 毫秒
141.
First successful design of semi-IPN hydrogel-silver nanocomposites: a facile approach for antibacterial application 总被引:4,自引:0,他引:4
Murthy PS Murali Mohan Y Varaprasad K Sreedhar B Mohana Raju K 《Journal of colloid and interface science》2008,318(2):217-224
Semi-IPN hydrogels in which poly(vinyl pyrrolidone) (PVP) chains were physically dispersed throughout poly(acrylamide) (PAM) gel networks were synthesized. These semi-IPN hydrogel networks can act as excellent nanoreactors for producing and stabilizing metal nanoparticles. The current methodology allows us to entrap metal nanoparticles throughout hydrogel networks via PVP chains. An optimized semi-IPN hydrogel formulation was found to produce silver nanoparticles, ca. 3-5 nm. The synthesized semi-IPN hydrogel-silver nanocomposites were fully characterized by using UV-vis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The developed semi-IPN hydrogel-silver nanocomposite (SHSNC) was evaluated for preliminary antibacterial applications. 相似文献
142.
M. Lakshmi Kantam Koosam Mahendar Bojja Sreedhar Boyapati. M. Choudary Suresh K. Bhargava Steven H. Priver 《Tetrahedron》2010,66(27-28):5042-5052
The Mannich-type reaction between alkyl, aryl and heterocyclic aldimines and sulfonium salts for the synthesis of α-sulfanyl-β-amino acid derivatives by using nanocrystalline magnesium oxide (NAP-MgO) is described. These products are obtained in moderate to high yields with moderate diastereoselectivities. The configuration of ethyl-3-{[(4-methylphenyl)sulfonyl]amino}-2-(methylsulfanyl)-3-(4-nitrophenyl)propanoate (major isomer) has been confirmed by X-ray diffraction technique to be anti, and consistent with the assignment based on 1H NMR spectroscopy. These α-sulfanyl-β-amino acid derivatives are important building blocks for pharmaceuticals with potent biological activity. 相似文献
143.
The synthesis of nanostructured polyaniline (PANI) with different morphologies by simple alkali‐guided template‐free method followed by doping them with vanadium has been described. The synthesized polyaniline nanoparticles have been well characterized by various techniques. Further, the catalytic activity of the undoped and doped PANI nanostructures for selective oxidation of sulfides to sulfoxides in water has been studied. It was observed that the special morphology of nanostructures plays an important role in enhancement of catalytic activity. Vanadium‐doped PANI nanotubes and nanorods showed higher activity and selectivity than nanospheres. The catalyst has been reused for five consecutive cycles with consistent activity. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
144.
D.C. Krishna Y. Kalyana Lakshmi B. Sreedhar P. Venugopal Reddy 《Solid State Sciences》2009,11(8):1312-1318
Nanocrystalline A-doped manganites, with compositional formula, Nd0.67A0.33MnO3 (A = Ca, Sr, Pb and Ba) were prepared by Polyvinly Alcohol (PVA) gel route. After characterizing the samples by X-ray diffraction studies and by measuring electrical, magnetic transition temperatures, a systematic investigation of magnetization and magnetoresistance measurements both as a function of magnetic field and temperature was undertaken. The variation of electrical and magnetic transition temperatures is explained on the basis of size variance parameter. It has been concluded from the M–H plots that NCMO, NPMO and NBMO samples are exhibiting narrow hystersis loops indicating soft ferromagnetic nature, while the NSMO is found to exhibit double hystersis loop indicating the presence of metamagnetic transition. It is also observed that among the four samples, Nd0.67Ca0.33MnO3 is found to exhibit the highest magnetoresistance (MR) of 91% over a broad temperature region. 相似文献