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A Simplified Method to Calculate the Wet Bulb Globe Temperature(WBGT)

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湖南大学学报（自然科学版） 2009年第S1期36卷 40-44页

作者： ZHANG Lei,MENG Qing-lin,ZHAO Li-hua,ZHANG Yu-feng(state key laboratory of subtropical building science,south china university of technology,guangzhou,Guangdong 51.640,china) state key laboratory of subtropical building science South China University of Technology Guangzhou 510640 China

Wet bulb globe temperature(WBGT)is a comprehensive index obtained mainly from three parameters:black globe temperature(Tg),wet bulb temperature(Tw),and dry bulb temperature(Ta).While in field observation and numerical simulation,black globe temperature and wet bulb temperature were not easy to obtain,so WBGT was difficult to measure and calculate *** order to solve this problem,air dry bulb temperature,wet bulb temperature,globe temperature,relative humidity,mean air velocity,solar radiation and wet bulb globe temperature were collected during the summer(July)in *** analysis and regression analysis were used to get a simplified method to calculate *** results showed that dry bulb temperature,relative humidity,solar radiation and WBGT were interrelated to some *** three parameters could be used in the simplified method to predict WBGT,and the linear correlation and precision of this model were *** addition,we used the measured data to verify the simplified method,and the results showed that the error of the calculated value and the measured value was all below 5%,which means the simplified calculating method is feasible and can be used in field observation and simulation research of urban thermal environment.

关键词： hot and humid regions urban thermal environment wet bulb globe temperature multivariate linear regression

A new relative radiometric consistency processing method for change detection based on wavelet transform and a low-pass filter

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science china(Technological sciences) 2010年第S1期53卷 7-14页

作者： SUN KaiMin1,SUI HaiGang1,2,LI DeRen1 & XU Chuan1,2 1 state key laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan university,Wuhan 430079,china 2 state key laboratory of subtropical building science,south china university of technology,guangzhou 51.640,china 1. state key laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China 2. state key laboratory of subtropical building science South China University of Technology Guangzhou 510640 China

The research purpose of this paper is to show the limitations of the existing radiometric normalization approaches and their disadvantages in change detection of artificial objects by comparing the existing approaches,on the basis of which a preprocessing approach to radiometric consistency,based on wavelet transform and a spatial low-pass filter,has been *** approach first separates the high frequency information and low frequency information by wavelet ***,the processing of relative radiometric consistency based on a low-pass filter is conducted on the low frequency *** processing,an inverse wavelet transform is conducted to obtain the results *** experimental results show that this approach can substantially reduce the influence on change detection of linear or nonlinear radiometric differences in multi-temporal images.

关键词： wavelet transform radiometric normalization low-pass filter change detection

Sound intensity radiated by Gaohu

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science china(Technological sciences) 2010年第7期53卷 1792-1797页

作者： ZHAO YueZhe1, WU ShuoXian1, QIU JianZhen1, HUANG Hong2 & WU LiLing2 1 state key laboratory of subtropical building science, south china university of technology, guangzhou 51.640, china 2 Department of Musicology, Xinghai Conservatoire of Music, guangzhou 510500, china 1. state key laboratory of subtropical building science South China University of Technology Guangzhou 510640 China2. Department of Musicology Xinghai Conservatoire of Music Guangzhou 510500 China

Gaohu is one of the main bowed stringed instruments used in Guangdong music and Chinese native Orchestra. However its sound intensity has never been carefully measured. In this paper the sound power measurements of Gaohu were performed in a reverberation chamber according to the Chinese national standard. Two qualified musicians performed on their own instruments. The mean sound power levels and the dynamic ranges of Gaohu were investigated by four channel acoustic measuring equipments when single notes, music scale and melodies were performed under pp, mp, f and ff dynamics. Great differences were found when Gaohu performed single notes, while the sound power levels were quite close when music scale were performed under f dynamic to those when melodies were performed under normal dynamic mark, the sound power levels of Gaohu when music scale was performed under f dynamics were suggested as the typical and representative value of the sound intensities of Gaohu instrument.

关键词： Gaohu Guangdong music sound intensities sound power level

REACTION MECHANISM OF BENZOPHENONE-PHOTOINITIATED CROSSLINKING OF POLYETHYLENE

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Chinese Journal of Polymer science 2002年第4期20卷 291-307页

作者： Bao-jun Qu state key laboratory of Fire science and Department of Polymer science and Engineering university of science and technology of china Hefei 230026 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 radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in detail. The spin-trapping electron spin resonance (ESR) spectra obtained from the LDPE/BP systems with spin-trap agents show that two kinds of polymer radical intermediates are mainly formed: tertiary carbon and secondary carbon radicals. The spin-trapping ESR studies of MD/BP systems give further evidence that photocrosslinking reactions of PE predominantly take place a sites of tertiary carbon, secondary carbon, and especially allylic carbon when available. The high resolution C-13-NMR spectra obtained from LDPE and MD systems show that the crosslink microstructures have H- and Y-type links and that their concentrations are of the same order. The fluorescence, ESR, C-13 and H-1-NMR spectra from the PE and MD systems demonstrate that the main photoreduction product of BP (PPB) is benzpinacol formed by the recombination of two diphenylhydroxymethyl (K-.) radical intermediates. Two new PPB products: an isomer of benzpinacol with quinoid structure, 1-phenylhydroxymethylene-4-diphenylhydroxymethyl-2,5-cyclobexadiene and three kinds of alpha-alkyl-benzhydrols have been detected and identified. These results provide new experimental evidence for elucidating the reaction mechanism in the BP-photoinitiated crosslinking of polyethylene.

关键词： photocrosslinking mechanism polymer radical intermediates crosslink microstructures photolytic products of benzophenone polyethylene model compound

Evolution of Bright Screening-photovoltaic Spatial Optical Solitons

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Chinese Journal of Lasers 2001年第5期10卷 28-33页

作者： LIU Jinsong (state key laboratory of Laser technology, Huazhong university of science and technology, Wuhan 430074, china) 华中科技大学激光技术国家重点实验室湖北武汉

A numerical analysis of the dynamical evolution of bright screening photovoltaic (SP) spatial solitons in biased photovoltaic photorefractive materials in the case of neglecting the material loss and the diffusion is presented. When an incident optical beam is a bright SP soliton, the beam propagates along a linear path with its shape kept unchanged. When the incident optical beam is slightly different from a bright SP soliton, the beam reshapes itself and tries to evolve into a bright SP soliton after a short distance. However, when the incident optical beam is significantly different from a SP bright soliton, the beam cannot evolve into a stable bright SP soliton, and tends to experience periodic compression and expansion. For a low intensity input beam, the wave experiences a periodic process of compression first and then expansion during the initial part of the cycle. For a high intensity input beam, however, the wave will initially diffract and then experiences compression during the cycle.

关键词： nonlinear optics spatial optical solitons photorefractive effects

Effect of Powder Particle Size on the Properties and Microstructure of Ti(C,N)-Based Cermet

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Rare Metals 2001年第1期20卷 47-51页

作者： Yong Zheng, Weihao Xiong (key state laboratory of Die technology, Huazhong university of science and technology, Wuhan 430074, china) Huazhong Univ Sci & Technol Key State Lab Die Technol Wuhan 430074 Peoples R China

The influence of raw powder particle size on the properties and microstructures of Ti (C, N)-based cermets has been studied. The conclusions are as follows: The microstructures of cermets were composed of two kinds of grains, the one with black cores surrounded by obvious rim structures, and the other whose cores were white with unconspicuous rim structures and adhesive phase. In the cermet made from fine powders, the amount of grains with white cores was much more than that in cermet made from coarse powders. In addition, their properties were also much better.

关键词： Ti(C, N)-based cermet powder particle size property microstructure

Distribution of Nb atom in the TiAl+Nb system

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Rare Metals 2001年第1期20卷 5-12页

作者： Xiaodong Ni, Xidong Hui, Guoliang Chen (Applied science School, university of science and technology Beijing, Beijing 100083, china state key laboratory for Advanced Metals and Materials, university of science and technology Beijing, china) Appl. Sci. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Based on MEAM (the modified embedded atom method) potential and an average atom model similar to B-W (Bragg-Williams) method, the distribution of Nb atoms in TiAl+Nb compounds with various composition was calculated. The calculation results showed that Nb atoms prefer to occupy the Ti sublattice of L10 structure for all compounds in question. With increasing atomic fraction of Nb and Al, Nb atoms exhibited a trend of ordered distribution on the Ti sublattice and result in a new L10 derivative superlattice structure.

关键词： Computer simulation Intermetallics Superlattices Ternary systems

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 230026 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

Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

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science china Chemistry 2008年第1期51卷 51-57页

作者： OU BaoLi1,2 LI DuXin2 1 College of Chemistry and Chemical Engineering,Hunan university of science and technology,Xiangtan 411201, china 2 state key laboratory of Powder Metallurgy,Central south university,Changsha 410083, china 1. College of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan 411201 China 2. state key laboratory of Powder Metallurgy Central South University Changsha 410083 China

Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles.

关键词： silica nanoparticles surface modification atom transfer radical polymerization polystyrene hybrid particle