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Spectra of Composition Operators on Lummer-Hardy Spaces

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Acta Mathematica Sinica,English Series 1994年第2期10卷 209-214页

作者： Yuan Jinyong department of Mathematics university of science and technology of china {2., 2.002. china 1. department of Mathematics University of Science and Technology of China 230027 Heifei China

In this paper, we completely determine the spectrum of a compact composition operator on Lummer-Hardy space.

关键词： LH Spectra of Composition Operators on Lummer-Hardy Spaces

One-pot synthesis of hyperbranched poly(amido amine) clicked with a sugar shell via Michael addition polymerization and thiol click reaction

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science china {2. 2010年第8期53卷 1663-1668页

作者： YU ZhiQiang,CUI MengMeng,YAN JunJie & YOU YeZi CAS Key Lab of Soft Matter chemistry department of Polymer {2. and Engineering,university of {2. and technology of china,hefei 2.002.,china 1. CAS Key Lab of Soft Matter chemistry department of Polymer science and Engineering University of Science and Technology of China Hefei 230026 China

This paper reports the production of glycopolymers via a simple and flexible method.A novel glycopolymer with a hyperbranched poly(amido amine) core and a sugar shell (HPAA-GLc) was synthesized by using thiol-ene click reaction via facile one-pot *** poly(amido amine) with vinyl terminals was first synthesized by Michael addition polymerization of N,N'-methylene bisacrylamide (MBA) with 1-(2.aminoethyl) piperazine (AEPZ).Subsequently,thiol-ene click reaction between vinyl units of hyperbranched poly(amido amine) and thio-glucose was performed in *** on the NMR result,all the vinyl groups reacted with thiol-glucose in 12. *** photoluminescence emission was observed from the aqueous solution of HPAA-GLc.

关键词： thiol-ene click reaction glycopolymers hyperbranched poly(amido amine) photoluminescence

Spectrum characteristics and pump wavelengths of Nd_(3+) -doped double-clad fiber

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Chinese science Bulletin 1997年第11期42卷 897-900页

作者： MING Hai, YANG Bao, DONG Xiaopeng, A. Fedotov, Xudong Xiao and M. M. T. Loy1. department of Physics, university of science and technology of china, {2. 2.002., china 2. department of Physics, university of science and technology of Hong Kong, Hong Kong, china department of Physics University of Science and Technology of China Hefei China department of Physics University of Science and Technology of Hong Kong Hong Kong China

Nd3+ -doped double-clad fiber is a new type of fiber that has large *** large receivingarea compared with single-clad rare-earth-doped *** Nd3+-doped double-clad fiberpumped directly by laser-diode arrays can be manufactured into high-power fiber lasers,high-power superfluorescence sources and high-gain fiber amplifiers,and they will be applied

关键词： double-clad fiber optimum pump wavelength optical spectrum.

Microstructure and thermal stability behavior of a rapidly solidified Al-Ti-Fe-Cr alloy

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Rare Metals 2002年第3期21卷 207-212页

作者： CHEN Yiqing, CAO Qingping, and SU YongSchool of Materials science and Engineering, hefei {2. of technology, hefei 2.0009, china School of Materials science and Engineering Hefei University of Technology Hefei 230009

A rapidly solidified Al-2.5Ti-2.5Fe-2.5Cr (mass fraction in percent) alloywas prepared by melt spinning. As-quenched and as-annealed microstructures were studied by X-raydiffractometry (XRD), transmission electron microscopy (TEM), high-resolution transmission electronmicroscopy (HREM) and energy dispersive spectrum (EDS) analysis. The microhardness of the alloy atdifferent annealing temperatures was measured. The results obtained indicate that the microhardnessof the rapidly solidified Al-2.5Ti-2.5Fe-2.5Cr alloy does not vary with different annealingtemperatures. The as-quenched microstructure of the alloy includes two kinds of dispersed primaryphases: Al_3Ti and Al_(13)(Cr, Fe)_2. After annealing at 400 deg C for 10 h, the stable phaseAl_(13)Fe_4 appears in the microstructure.

关键词： rapidly solidified Al-Ti-Fe-Cr alloy microhardness as-quenchedmicrostructure as-annealed microstructure

A STUDY OF OSCILLATING FLOWS OVER PROPAGATING RIPPLES:PART Ⅱ. VORTICITY DYNAMICS

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Journal of Hydrodynamics 2000年第1期12卷 8-15页

作者： Lu Xi yun department of Modern Mechanics, university of science and technology of china, {2. 2.002., P.R.china Univ of science and technology of China Hefei China

Vortex shedding for an oscillating flow over ripples is numerically investigated by solving 2. D time dependent incompressible Navier Stokes equations in curvilinear coordinates. The dynamics of vortex structures generated by flow separation is studied in order to understand some phenomena which take place near the bottom and in particular to get insight into the mechanism through which sediment grains are lifted up and maintained in suspension. Based on our calculated results, some important phenomena, such as vortex shedding, vortices pairing, vortices coalescence, vortex interaction with the free shear layer and so on, can be found. The behaviors of energy dissipation in the flow field and of shear stress along the ripple surface are also discussed for studying the dynamics of sediment grains in suspension and to obtain new information on the suspended load over the ripples.

关键词： oscillating flow ripple vorticity dynamics separation flow

A NEW SYNERGIST FOR INTUMESCENT FLAME RETARDANT POLYPROPYLENE

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Chinese Journal of Polymer science 2002年第4期20卷 377-380页

作者： Qiang Wu Bao-jun Qu State Key Laboratory of Fire science and department of Polymer science and Engineering university of science and technology of china, hefei 2.002. china Univ Sci & Technol china State Key Lab Fire Sci Hefei 230026 Peoples R China Univ Sci & Technol china Dept Polymer Sci & Engn Hefei 230026 Peoples R China

The synergistic effects of silicotungstic acid (SiW12. as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI), the UL-94 test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). The LOI data show that SiW12.added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGA data show that SiW12.apparently increases the thermal stability of the PP/IFR systems at high temperature (T > 500degreesC). The FTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW12.can induce a higher rate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on the carbonaceous microstructures. In short, a suitable amount of SiW12.(1.5 wt%) exerts synergistic effects with the IFR by increasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures on the burning PP surface.

关键词： silicotungistic acid synergistic effect intumescent flame retardant polypropylene

Some new results about Jacobi forms

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Chinese science Bulletin 1997年第3期42卷 181-183页

作者： WANG Jupingdepartment of Mathematics, university of science and technology of china, {2. 2.002., china department of Mathematics University of Science and Technology of China Hefei China

THE one-dimensional Jacobi forms were first systematically investigated by Eichler and Zagier, and a similar theory in a higher-dimensional case was developed by Ziegler, who gave the precise definition and some basic properties of higher-dimensional Jacobi forms. This note tries to give a satisfactory classification for a large kind of spaces of Jacobi forms. To be a little more explicit, we get a rank formula for Jacobi forms and then show that either all the

关键词： Jacobi forms rank coefficient estimation.

Density functional study on enantioselective reduction of keto oxime ether with borane catalyzed by oxazaborolidine

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science china {2. 2006年第4期49卷 296-307页

作者： LI Ming1, ZHENG Wenxu2.& TIAN Anmin2.1. department of {2., Southwest-china Normal university, Chongqing 400715, china 2. department of chemistry, Sichuan university, Chengdu 610064, china 1. department of chemistry Southwest-China Normal University Chongqing 400715 China 2. department of chemistry Sichuan University Chengdu 610064 China

The enantioselective reduction of keto oxime ether with borane catalyzed by oxazaborolidine is discussed by the density functional theory (DFT) method. The main intermediates and transition states for this reaction are optimized completely at the B3LYP/6-31g(d) level, and the transition states are verified by vibrational modes. As shown, the chirality-controlled steps for this re- action are the hydride transfer from borane to carbonyl carbon and oxime carbon of keto oxime ether, and the chirality for the reduced products is determined in these two reaction steps. In all examined reaction paths, the first hydride is transferred via a six-membered ring and the second hydride via a five-membered ring or a four-membered ring.

关键词： keto oxime ether, oxazaborolidine, enantioselective reduction, DFT.

Investigation of 'chazi'(damaged-enamels)on Chenghua doucai Porcelains

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science china(Technological sciences) 2009年第6期52卷 1722-1729页

作者： DU Feng1 & SU BaoRu2.1 Institute of chemistry & Molecular Engineering,Qingdao {2. of science & technology,Qingdao,china 2.College of Information science & technology,Qingdao {2. of science & technology,Qingdao,china Institute of chemistry & Molecular Engineering Qingdao University of Science & Technology Qingdao China College of Information science & technology Qingdao University of Science & Technology Qingdao China

At the end of the 1950s,Sun Yingzhou considered that the 'chazi'(damaged colour)on Chenghua doucai imperial porcelain as a defect was originally produced in firing process during Chenghua period(1465―1487).Researchers in china have accepted his *** any fragment with the 'chazi' has never been found in several tons of Chenghua imperial sherds excavated from Ming imperial kiln site in *** china,few scholars have questioned the formation of 'chazi',and further investigated *** researchers at the Research Laboratory in the British Museum,employing unde-structive EDXRF,have analyzed the chemical composition of the 'chazi'(damaged colour)on a Chen-ghua doucai stem cup in the museum,and they have confirmed that the 'chazi'(damaged colour)was caused by the fire of the Jianfu palace in the Forbidden City in *** on their research,the authors studied the colour chemical principle of the 'chazi's' formation *** to the ceramic {2. principle,scientific reasoning for the 'chazi' was carried *** the help of the history of Qing court,the brainteaser of the 'chazi' was totally uncovered,the misunderstanding for the 'chazi' has also been *** research also suggests that employing modern science and {2. is a direction to study Chinese ancient ceramic further.

关键词： Chenghua doucai porcelains court eunuchs the set on fire at the Jianfu palace ’chazi’(damaged-enamels) the British Museum colour chemical principle archaeology using science and technology