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1.
Ruoyu Hong * Jianmin Ding Guoliang Zheng College of Chemistry Chemical Engineering Soochow University Suzhou P. R. China Institute of Process Engineering Chinese Academy of Sciences Beijing P. R. China IBM HYDA/- C Highway North Rochester MN USA *Author to whom correspondence should be addressed. E-mail: rhong@suda.edu.cn 《中国颗粒学报》2004,2(5):207-214
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
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3.
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.
JIANG DiHua NIEN ChuFeng & QIN YuJun School of Mathematics University of Minnesota Minneapolis MN USA 《中国科学 数学(英文版)》2010,(3)
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.
Dr. Hiroshi Hinou Risho Miyoshi Yasuaki Takasu Hirokazu Kai Dr. Masaki Kurogochi Dr. Shingo Arioka Dr. Xiao‐Dong Gao Dr. Nobuaki Miura Dr. Naoki Fujitani Dr. Shinya Omoto Dr. Tomokazu Yoshinaga Dr. Tamio Fujiwara Dr. Takeshi Noshi Dr. Hiroko Togame Prof. Hiroshi Takemoto Prof. Shin‐Ichiro Nishimura 《化学:亚洲杂志》2011,6(4):1048-1056
A potent inhibitor for Vibrio cholerae neuraminidase (VCNA) was developed by using a novel two‐step strategy, a target amino acid validation using mechanism‐based labeling information, and a potent inhibitor search using a focused library. The labeling information suggested the hidden dynamics of a loop structure of VCNA, which can be a potential target of the novel inhibitor. A focused library composed of 187 compounds was prepared from a 9‐azide derivative of 2,3‐dehydro‐N‐acetylneuraminic acid (DANA) to interrupt the function of the loop of the labeled residues. Inhibitor 3c showed potent inhibition properties and was the strongest inhibitor with FANA, a N‐trifluoroacetyl derivative of DANA. Validation studies of the inhibitor with a detergent and a Lineweaver–Burk plot suggested that the 9‐substitution group would interact hydrophobically with the target loop moiety, adding a noncompetitive inhibition property to the DANA skeleton. This information enabled us to design compound 4 having the combined structure of 3c and FANA. Compound 4 showed the most potent inhibition (Ki=73 nM , mixed inhibition) of VCNA with high selectivity among the tested viral, bacterial, and mammal neuraminidases. 相似文献
6.
The synthesis of C1-C20 and C15-C27 segments of Aplyronine A is described. Oxidative cleavage of cyclic vinyl sulfones has been used to prepare key fragments of Aplyronine A. Key precursors are united by Horner-Wadsworth-Emmons and Julia-Kociensky olefination for the respective elaboration of the C1-C20 and C15-C27 segments. 相似文献
7.
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
8.
Noshi MN El-awa A Torres E Fuchs PL 《Journal of the American Chemical Society》2007,129(36):11242-11247
Functionalized cyclic vinyl sulfones were directly converted to the "polarity reversed" vinyl phosphonates through an efficient one pot procedure. Ozonolysis of these vinyl sulfones and vinyl phosphonates furnish complementary sets of termini-differentiated ester-aldehydes. This strategy has been applied for preparation of segments needed for the synthesis of Aplyronine A. The scope and limitations of this transformation were defined. 相似文献
9.
Muhammad Zakria Butt Mozina Noshi Farooq Bashir 《Central European Journal of Physics》2008,6(4):834-842
The mode of planar distribution of solute atoms in Cu single crystals alloyed with 0.5 to 8.0 at.%Ge has been investigated
via the temperature dependence of the critical resolved shear stress of these alloys. It is found that there exists a critical
solute concentration c
m
≈ 5 at.%Ge below which the distribution of solute atoms in the crystal is random, and above which some local ordering occurs.
This together with such data available in the literature for Cu-Zn, Cu-Al and Cu-Mn alloys, i.e. c
m
≈7 at. %Zn, 7 at.%Al and 1 at.%Mn, when examined as a function of the size-misfit factor δ = (1/b)(db/dc)of a given binary alloy system, shows that the value of c
m
strongly depends on δ; the smaller the magnitude of δ, the greater the value of c
m
and vice versa. Also, the value of c
m
is found to correlate well with the electron-to-atom ratio (e/a)of the Cu-Zn, Cu-Al, Cu-Ge and Cu-Mn alloys with the solute concentration c = c
m
. However, no systematic correlation exists between the critical solute concentration c
m
for the onset of local ordering and the modulus-mismatch parameter η = (1/G)(dG/dc).
相似文献
10.
Kolundzic F Noshi MN Tjandra M Movassaghi M Miller SJ 《Journal of the American Chemical Society》2011,133(23):9104-9111
Catalytic enantioselective indole oxidation is a process of particular relevance to the chemistry of complex alkaloids, as it has been implicated in their biosynthesis. In the context of synthetic methodology, catalytic enantioselective indole oxidation allows a rapid and biomimetic entry into several classes of alkaloid natural products. Despite this potentially high utility in the total synthesis, reports of catalytic enantioselective indole oxidation remain sparse. Here we report a highly chemoselective catalytic system for the indole oxidation that delivers 3-hydroxy-indolenines with good chemical yields and moderate to high levels of enantio- and diastereoselectivity (up to 95:5 er and up to 92:8 dr). These results represent, to our knowledge, the most selective values yet reported in the literature for catalytic asymmetric indole oxidation. Furthermore, the utility of enantioenriched hydroxy-indolenines in stereospecific rearrangements is demonstrated. 相似文献