首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7篇
  免费   0篇
化学   2篇
力学   1篇
数学   1篇
物理学   3篇
  2010年   1篇
  2004年   1篇
  2002年   1篇
  2001年   2篇
  1989年   1篇
  1985年   1篇
排序方式: 共有7条查询结果,搜索用时 0 毫秒
1
1.
1. Introduction1.1 Silica nanoparticles and synthesis methods Silica (SiO2) nanoparticles are widely used in industry asan active filler for polymer reinforcement, a rheologicaladditive in fluids, a free flow agent in powders, and anagent for chemical mechanical polishing during IC (inte-grated circuit) fabrication (Sniegowski & de Boer, 2000).Silica powder is also used for producing silicon carbide(Koc & Cattamanchi, 1998) or opaque silica aerosols (Leeet al., 1995). Many methods can …  相似文献   
2.
3.
MN Vinoj  VC Kuriakose 《Pramana》2001,57(5-6):987-1001
In this paper, we consider nonlinear Schrödinger (NLS) equations, both in the anomalous and normal dispersive regimes, which govern the propagation of a single field in a fiber medium with phase modulation and fibre gain (or loss). The integrability conditions are arrived from linear eigen value problem. The variable transformations which connect the integrable form of modified NLS equations are presented. We succeed in Hirota bilinearzing the equations and on solving, exact bright and dark soliton solutions are obtained. From the results, we show that the soliton is alive, i.e. pulse area can be conserved by the inclusion of gain (or loss) and phase modulation effects.  相似文献   
4.
In this paper, we summarize the basic structures and properties of irreducible symplectic supercuspidal representations of GLn(F) over a p-adic local field F with characteristic zero, and explore possible topics for further investigation.  相似文献   
5.
AK Banerjee  MN Alam  AA Mamun 《Pramana》2001,56(5):643-656
Obliquely propagating altra-low-frequency dust-electromagnetic waves in a self-gravitating, warm, magnetized, two fluid dusty plasma system have been investigated. Two special cases, namely, dust-Alfvén mode propagating parallel to the external magnetic field and dustmagnetosonic mode propagating perpendicular to the external magnetic field have also been considered. It has been shown that effects of self-gravitational field, dust fluid temperature, and obliqueness significantly modify the dispersion properties of these ultra-low-frequency dust-electromagnetic modes. It is also found that in parallel propagating dust-Alfvén mode these effects play no role, but in obliquely propagating dust-Alfvén mode or perpendicular propagating dust-magnetosonic mode the effect of self-gravitational field plays destabilizing role whereas the effect of dust/ion fluid temperature plays stabilizing role.  相似文献   
6.
We report the enantiospecific synthesis of the sterically congested all-cis 2,3,4,5-substituted pyrrolidines 4, 5, and 6, from either D- or L-serine. Hemiaminal intermediate 13 is converted to the fully substituted pyrrolidine 15 by way of a tandem Wittig-Michael reaction. The endo stereochemistry of the C-3 methyl group of compound 15 is set by stereoselective reduction of the double bond in 11, driven by a preference for hydrogenation from the rear side of the molecule. The all-cis configuration of these fully substituted pyrrolidines has been established by X-ray analysis of compound 6. Removal of the benzenesulfonyl group from the highly substituted and functionalized intermediate 15 is successfully accomplished by sodium naphthalenide reduction.  相似文献   
7.
7-Alkyl-substituted aporphinoids were obtained in moderate yield through the reaction of N-protected 1-ethylidine-1,2,3,4-tetrahydroisoquinolines with benzyne. 7-Alkoxy and 7-chloro derivatives were also prepared by this route, though in lower yield. Mechanistic proposals for the aromatization step are discussed.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号