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REACTION MECHANISM OF BENZOPHENONE-PHOTOINITIATED CROSSLINKING OF POLYETHYLENE

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

作者： Bao-jun Qu state key {2. 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 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

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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 {2. 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

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Binary fire-extinguishing agent composed of halocarbons and inert gases

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Progress in Natural Science:Materials International 2006年第3期16卷 292-296页

作者： ZHOU Xiaomeng, ZHANG Yongfeng and LIAO Guangxuan (state key {2. of fire Science, university of Science and technology, hefei 2.002., china) [a]state key {2. of fire Science University of Science and Technology Hefei China

C3H2.3Br (132.) is a new kind of Halon replacements developed by our research group. In order to improve the disperse capability of 132., nitrogen was mixed with 132. to form the binary fire-extinguishing agent. In this work, the binary fire-extinguishing agent of nitrogen and 132. was used in experiment and the fire extinguishing efficiency was discussed. In addition, the fire suppression mechanism was investigated and the fire-extinguishing concentration of nitrogen and 132. was also studied.

关键词： Halon replacement nitrogen C3H2.3Br synergistic fire extinguishing concentration.

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Community-based prevention and treatment of cardiovascular diseases

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Journal of Geriatric Cardiology 2024年第3期21卷 315-322页

作者： Sheng-Shou HU The Writing Committee of the Report on Cardiovascular Health and Diseases in china Fuwai Hospital National Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

The Annual Report on Cardiovascular Health and Diseases in china(2.2.)intricate landscape of cardiovascular health in *** is the third section of the report with a specific focus on community-based prevention and treatment of cardiovascular diseases(CVD).This section of the report underscores the importance of initiatives outlined in the"Healthy china 2.30 Plan,"emphasizing the comprehensive prevention and control strategy for chronic diseases.A {2. aspect of this plan involves the establishment of national demonstration areas aimed at comprehensive prevention and control of chronic *** 2.2.,488 such areas had been set up across china,surpassing the initial target and covering a significant proportion of counties and *** report highlights the successful implementation of these strategies in Lishan district,Anshan city,where demonstration areas for comprehensive prevention and control of chronic diseases were launched in *** the course of seven years,the number of healthy units increased substantially,leading to improvements in managing risk factors for CVD among *** reductions in prevalence rates of overweight,obesity,smoking,passive smoking,and drinking were observed,along with the development of healthier behaviors among ***,Qiaokou district in Wuhan City,designated as a national demonstration area in 2.14,implemented comprehensive public health promotion ***,special clinics for hypertension intervention were established,contributing to an increase in self-reported rates of hypertension,a slight decrease in prevalence,and a remarkable improvement in the control rate among treated ***,these efforts underscore the effectiveness of community-based approaches in driving positive health outcomes and advancing the comprehensive prevention and control of chronic diseases,particularly cardiovascular diseases,in china.

关键词： prevention district treatment

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Experimental study on fire smoke movement in a multi-floor and multi-room building

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Science china(Technological Sciences) 2005年第3期48卷 292-304页

作者： ZHONG Maohua 1, 2., LI Peide 2., LIU Tiemin 1 , WEI Xing 1, 2.& LIAO Guangxuan 2.1. National Center of Safety Science and technology, state Administration of Work Safety, Beijing 10002.,{2. 2. state key laboratory of fire Science, university of Science and technology of{2., hefei 2.002.,{2. 1. National Center of Safety Science and technology State Administration of Work Safety 100029 Beijing China 2. state key {2. of fire Science University of Science and Technology of China 230026 Hefei China

fire smoke movement of multi-floor and multi-room (MFMR) fire was studied at the model test building in {2. key laboratory of fire Science (SKLFS). The ingredient, temperature, air pressure difference and air velocity of smoke were measured and analyzed. Meanwhile, the hazard of smoke ingredient to exposed occupants was analyzed based on the national standard, Occupational Exposure Limit for Hazardous Agents in the Workplace (GBZ2.2.02.. The experimental results showed that the maximum temperature difference in MFMR fire was located along the vertical height from the fire source. With the spreading and diffusion of smoke, the temperature of smoke layer would tend to be no difference. In the fire of woodpile and kerosene, the main smoke ingredients such as SO 2., CO and CO 2.would first exceed human’s average physiological limit, while smoke ingredients such as NO and NO 2.would come behind. Because of the higher fluctuation range and frequency of air pressure difference of smoke in multi-layer building fire, the fire smoke would spread around everywhere of the passageway and made the human evacuation more difficult.

关键词： multi-floor and multi-room,fire experiment,smoke spread,smoke toxicity.

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Recent progress in polymer/layered double hydroxide nanocomposites

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Progress in Natural Science:Materials International 2006年第6期16卷 573-579页

作者： DING Peng, CHEN Wei and QU Baojun (state key {2. of fire Science and Department of Polymer Science and Engineering, university of Science and technology of china, hefei 2.002., china) [a] state key {2. of fire Science and Department of Polymer Engineering University of Science and Technology of china Hefei China

New developments in the studies of nanocomposites based on polymer matrixes and layered double hydroxides (LDHs) in recent years are reviewed combining our relative research work, among which the synthesis techniques, the physicochemical characterizations, and the improved material properties are especially discussed. The possible application of polymer/LDH nanocomposites is also proposed.

关键词： nanocomposite layered double hydroxide synthesis characterization structure property.

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Calculation of maximum ground movement and deformation caused by mining

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中国有色金属学会会刊：英文版 2011年第S3期21卷 562-569页

作者： LI Pei-xian1, 2. TAN Zhi-xiang1, 2. DENG Ka-zhong1, 2.1. key laboratory for Land Environment and Disaster Monitoring of {2. Bureau of Surveying and Mapping, china university of Mining and technology, Xuzhou 2.1116, china 2. Jiangsu key laboratory of Resources and Environmental Information Engineering, china university of Mining and technology, Xuzhou 2.1116, china [a] key laboratory for Land Environment and Disaster Monitoring of {2. Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China [b] Jiangsu key laboratory of Resources and Environmental Information Engineering China University of Mining and Technology Xuzhou 221116 China

In order to know the maximum mining ground deformation of arbitrary surface point, directions of the maximum surface tilt, curvature,horizontal displacement and horizontal deformation caused by multi-working faces were deduced based on probability integral method. The distribution forms of surface deformations in all direction φ∈[0, 2.] were obtained and also equations of maximum deformations were given based on calculation of mining ground deformation in direction φ. A mining subsidence analysis system was developed with VB6.0. The system implements the probability integral mining subsidence prediction with direct integration method, and it can avoid errors of arbitrary shaped working face subdivision of traditional method, and accuracy of mining subsidence prediction can be improved with the direct integral method. The system implements the contour chart and profile chart and also data analysis automation by manipulation of the SURFER kernel function and it complements the defect of existing subsidence prediction software. Calculation of maximum deformations caused by multi-working faces mining in a coal mine of Xuzhou, china was shown as application example. Engineering application indicates that maximum deformation of mining ground surface can be calculated and analyzed by the system. The research provides a theoretical basis and calculation tool for mining subsidence prediction and analysis.

关键词： mining subsidence probability integral method movement and deformation system development

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Influence of rarefaction wave on premixed flame structure and propagation behavior

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Progress in Natural Science:Materials International 2007年第3期17卷 328-333页

作者： CHEN Xianfeng, SUN Jinhua, LU Shouxiang, CHU Guanquan, YAO Liyin and LIU Yi (state key {2. of fire Science, university of Science and technology of china, hefei 2.002., china) [a]state key Laboratoiy of {2. Science University of Science and Technology of China Hefei China

To explore the influence of rarefaction wave on the structure and propagation behavior of the premixed propane/air flame in a rectangle combustion pipe, the techniques of high speed Schlieren photograph method, pressure measurement and so on are used to study the interaction processes between rarefaction wave and flame. Two cases of rarefaction wave-flame interaction were performed in the experiment. The experimental result shows that both the rarefaction waves can cause the flame transition from laminar to turbulent combustion quickly. The cowflow rarefaction wave decreases the flame speed, while the counterflow rarefaction wave leads the flame propagation speed to increasing on the whole, accompanied with sharp vibration.

关键词： gas explosion rarefaction wave flame propagation laminar flame turbulent combustion.

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Subsidence control and farmland conservation by solid backfilling mining technology

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中国有色金属学会会刊：英文版 2011年第S3期21卷 665-669页

作者： GUO Guang-li1, 2. FENG Wen-kai3, ZHA Jian-feng1, 2. 3, LIU Yuan-xu1, 2. WANG Qiang1, 2.1. key laboratory for Land Environment and Disaster Monitoring of the {2. Bureau of Surveying and Mapping, china university of Mining and technology, Xuzhou 2.1116, china 2. Jiangsu key laboratory of Resources and Environmental Information Engineering, china university of Mining and technology, Xuzhou 2.1116, china 3. {2. key laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu university of technology, Chengdu 610059, china [a] key laboratory for Land Environment and Disaster Monitoring of the {2. Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China [b] Jiangsu key laboratory of Resources and Environmental Information Engineering China University of Mining and Technology Xuzhou 221116 China [c] state key {2. of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China

Solid backfilling mining technology, which decreases the height of fissure zone and caving zone, and alleviates the subsidence, is a new technology for farmland conservation. Based on the situation analysis of farmland destruction in mining area, three ways for farmland protection were proposed. In order to improve the feasibility of this technology, the limited filling materials should be used to increase resources recovery ratio, and then the surplus materials could be backfilled into goaf. An index, namely farmland conservation ability, was put forward to optimize the ways for farmland conservation. At last, the Wanbei coal mine was taken as a case for farmland conservation. It was shown that 32.0 t dull coal was substituted and 52.hm2.farmland was conserved by solid backfilling mining in this coal mine.

关键词： solid backfilling farmland conservation mining subsidence equivalent mining height

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Mining subsidence control by solid backfilling under buildings

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中国有色金属学会会刊：英文版 2011年第S3期21卷 670-674页

作者： ZHA Jian-feng1, 2. 3, GUO Guang-li1, 2. FENG Wen-kai3, WANG Qiang1, 2.1. key laboratory for Land Environment and Disaster Monitoring of the {2. Bureau of Surveying and Mapping, china university of Mining and technology, Xuzhou 2.1116, china 2. Jiangsu key laboratory of Resources and Environmental Information Engineering, china university of Mining and technology, Xuzhou 2.1116, china 3. {2. key laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu university of technology, Chengdu 610059, china [a] key laboratory for Land Environment and Disaster Monitoring of the {2. Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China [b] Jiangsu key laboratory of Resources and Environmental Information Engineering China University of Mining and Technology Xuzhou 221116 China [c] state key {2. of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China

Solid backfilling mining can reduce the buildings' damage caused by mining greatly. The reduction of subsidence value, the slow advancing speed and the subsidence caused by backfilling body compaction are the main reasons that solid backfilling mining velocity decreases significantly. Based on the research of mechanism, some principles on subsidence control of solid backfilling mining under buildings were proposed. The equivalent mining height was designed according to the fortification criteria of buildings and their attachment structures, which enables the ground movement and deformation caused by mining to be less than the corresponding fortification criteria.

关键词： solid backfilling mining subsidence control mining under buildings

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