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Cure of a New Type Composite on Noise Control and Effect of Filler Modification

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Journal of Materials Science & Technology 2003年第Z1期19卷 135-136页

作者： jun CAI fei XU Weimin CAI School of Municipal and Environment Englineering Harbin Institute of Technology Harbin150001china School of Environment Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China School of Environment Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

A new type composite of high efficiency sound attenuation was cured. The superfine tungsten powder, plasticizerand stabilizer are added into the PVC resin and blended in the mixing chamber of a HAAKE rheometer. The effect ofthe filler modification is considered in the composite cure. The properties of modified composite and unmodified oneare studied by SEM morphology viewing, acoustic and mechanical measurement. The test results indicate that thereason of the better soundproof and mechanical properties is the particle uniform dispersion and stronger adhesion.

关键词： Composite, Filler modification, Soundproof property, Mechanical property

The dynamic impact of income and income distribution on food consumption among adults in rural China

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Journal of Integrative Agriculture 2021年第1期20卷 330-342,I0001,I0002页

作者： LI Lei ZHAI Shi-xian BAI jun-fei National Agricultural and Rural Development Research Institute China Agricultural UniversityBeijing 100083P.R.China Beijing Food Safety Policy&Strategy Research Base Beijing 100083P.R.China College of Economics and Management China Agricultural UniversityBeijing 100083P.R.China

Previous studies have demonstrated that income has a significant effect on food demand in rural China. However, little research has focused on the dynamic impact of income and income distribution on food demand in rural China. Using China Health and Nutrition Survey data, this study employs a consistent two-step quadratic almost ideal demand system model, with addressed problems of endogeneity of total expenditure and zero shares, to estimate the food demand elasticities among adults in rural areas with regard to the different income strata. The results show that changes in income and income strata have significant effects on food demand in rural areas. Except for grains, all other food groups, including vegetables, oils and fats, animal products, and other foods, have positive income elasticities, and the rise in the income strata will lead to declining income elasticities for grains, vegetables, oils and fats, and animal products. Based on the estimated income elasticities, the food consumption projections indicate that reducing income inequality in rural society can improve the living standard of low-income people in terms of nutrient intakes.

关键词： income redistribution food demand endogeneity censored demand system rural China

Food economics and policies: Challenges and approaches toward better nutrition and safer food in China

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Journal of Integrative Agriculture 2019年第8期18卷 1737-1739页

作者： BAI jun-fei ZHU Chen Beijing Food Safety Policy & Strategy Research Base China Agricultural University

China has achieved unprecedented successes in feeding the 1.3 billion population in the past few decades. Per capita occupation of grain and milk increased from 316.6 and 1 kg in 1978 to 445.7 and 26.85 kg in 2016, respectively. Per capita meat occupation also reached 61.9 kg in 2016 from nearly nothing at the beginning of the reform and opening (NBSC 1979-2018). With these successes in agricultural production, the quality of food consum ption has also improved significantly.

关键词： Food economics Challenges and approaches safer food

Distribution of platelet-derived growth factor-alpha receptor expressing oligodendrocyte precursor cells in the adult rat brain

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Neural Regeneration Research 2009年第12期4卷 1093-1098页

作者： Hongjun Yu jun fei Xue Luo Zhongxiang Yao Department of Rehabilitation Southwest Hospital Third Military Medical University Chongqing 400038 China Department of Histology and Embryology Third Military Medical University Chongqing 400038 China Trauma Center of Daping Hospital Third Military Medical University Chongqing 400038 China

BACKGROUND： Studies have demonstrated that NG2-positive glial cells in the adult rats are predominantly located in the gray and white matter of the cerebral cortex and hippocampus. Platelet-derived growth factor-a receptor （PDGF-αR） cells are a subset of oligodendrocytes, which are not as mature as NG2-positive cells. Distribution and migration of PDGF-αR-positive cells in the rat brain remain poorly understood. OBJECTIVE： Using immunohistochemical methods, the distribution of oligodendrocyte precursor cells （PDGF-αR-positive） was analyzed in the adult rat brain. DESIGN, TIME AND SETTING： Immunohistochemical study was performed at the Department of Histology and Embryology of the Third Military Medical University from September 2007 to September 2008. MATERIALS： Rabbit anti-PDGF-αR polyclonal antibody was purchased from Santa Cruz Biotechnology, USA. Streptomycin-avidin-biotin complex immunohistochemistry kit was purchased from Zhongshan Goldenbridge Biotechnology, China. METHODS： Whole brains from 5 healthy, adult, Wistar rats were collected for immunohistochemistry, and the mean value of PDGF-αR-expressing cells was quantified. The absolute values were translated to ranked data of high, moderate, and low grades （high grade： 10 positive cells; moderate grade： 5-9 cells; low grade：〈 5 cells in a 400 × visual field）. Based on the number of cell processes and branches, as well as the number of PDGF-αR-positive cells, in different regions, the cells were classified into three categories, i.e., type Ⅰ-Ⅲ. From type I to type Ill, the number of processes gradually increased. MAIN OUTCOME MEARSURES： The number and distribution of PDGF-αR-positive cells in different brain regions of adult rats. RESULTS： PDGF-αR-positive cells were located in the forebrain and midbrain, but not in the cerebellum or brainstem. In the olfactory bulb and hippocampus, a total of 60% PDGF-αR-positive cells were type Ⅰ and these cells were not mature as others. In the cerebral cortex, olfactory s

关键词： Platelet-derived growth factor-α receptor oligodendrocyte progenitor cells brain distribution

Research on Wavelet-Based Algorithm for Image Contrast Enhancement

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Wuhan University Journal of Natural Sciences 2004年第1期9卷 46-50页

作者： WuYing-qian DuPei-jun ShiPeng-fei InstituteofImageProcessingandPatternRecognition ShanghaiJiaotongUniversityShanghai200030China

A novel wavelet-based algorithm for image enhancement is proposed in the paper. On the basis of multiscale analysis, the proposed algorithm solves efficiently the problem of noise over-enhancement, which commonly occurs in the traditional methods for contrast enhancement. The decomposed coefficients at same scales are processed by a nonlinear method, and the coefficients at different scales are enhanced in different degree. During the procedure, the method takes full advantage of the properties of Human visual system so as to achieve better performance. The simulations demonstrate that these characters of the proposed approach enable it to fully enhance the content in images, to efficiently alleviate the enhancement of noise and to achieve much better enhancement effect than the traditional approaches. Key words wavelet transform - image contrast enhancement - multiscale analysis CLC number TP 391 Foundation item: Supported by the National Natural Science Foundation of China (69931010)Biography: Wu Ying-qian (1974-), male, Ph. D, research direction: image processing, image compression and wavelet.

关键词： wavelet transform image contrast enhancement multiscale analysis

Propagation patterns of microseismic waves in rock strata during mining:an experimental study

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International Journal of Minerals,Metallurgy and Materials 2019年第5期26卷 531-537页

作者： Dong Li jun-fei Zhang Cun-wen Wang Fu-xing Jiang School of Civil and Resources Engineering University of Science and Technology Beijing School of Civil Environmental and Mining Engineering The University of Western Australia

Microseismic monitoring has been widely used in mines for monitoring and predicting dynamic disasters such as rockbursts and waterbursts. However, to develop high-precision microseismic monitoring systems, the propagation patterns of microseismic waves under complex geological conditions must be elucidated. To achieve this aim, a simulation model of a typical coalmine was designed using similar materials according to the similarity theory to simulate the mining process. Geophones were embedded into the model to detect the propagation of elastic waves from microseisms. The results show that in an unmined solid rock mass, the wave velocity in shallow rock strata is mainly affected by geologically weak planes, whereas in deep strata it is affected mainly by the density of the rock mass. During propagation, the amplitude first decreases and then increases rapidly with increasing propagation distance from the coal layer. After mining, our results indicate that the goaf causes significant attenuation of the wave velocity. After the goaf was backfilled, the velocity attenuation is reduced to some extent but not eliminated. The results of this study can be used as guidelines for designing and applying microseismic monitoring systems in mines.

关键词： similar-materials simulation microseismic monitoring elastic wave velocity amplitude propagation

Ambient Temperature Living Radical Copolymerization of Styrene and Methyl Methacrylate with Sodium Hypophosphite as Reducing Agent

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Chinese Journal of Polymer Science 2015年第2期33卷 362-370页

作者：刘晓辉 Hui-na Li fei-jun Zhang Shan Xie Zhan-jun Liu 李彦国 School of Materials Science and Engineering Tianjin Key Laboratory of Fiber Modification and Functional FiberTianjin Polytechnic University College of Pharmacy Hebei United University State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences

A facile, safe and economical reducing agent, sodium hypophosphite（Na H2PO2·H2O）, has been successfully employed for ambient temperature living radical copolymerization of styrene（St） and methyl methacrylate（MMA）. Such effective reducing agent significantly improved the reactivity of low reactive St monomers during the copolymerization, where the reactivity ratios of St and MMA were determined to be 0.50 and 0.36 by Finemann-Ross method. Thus the copolymerizations proceeded fast and showed typical living/controlled features, as evidenced by pseudo first-order kinetics of polymerization, linear increase in molecular weight versus monomer conversion, and low polydispersity index values. Effects of the concentration of reducing agent and the monomer feed ratio on the copolymerization were investigated in detail. Furthermore, gel permeation chromatography and 1H-NMR analyses as well as chain extension experiments confirmed the high chain-end functionality of the resultant copolymer.

关键词： Controlled/living radical copolymerization Sodium hypophosphite Ambient temperature Methyl methacrylate Styrene

Demographics, societal aging, and meat consumption in China

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Journal of Integrative Agriculture 2015年第6期14卷 995-1007页

作者： MIN Shi BAI jun-fei James Seale Jr. Thomas Wahl Institute of Development and Agricultural Economics Leibniz University Hannover College of Economics and Management China Agricultural University Department of Food and Resource Economics University of Florida Department of Agribusiness and Applied Economics North Dakota State University

Drawn on the data collected by surveying 1 340 urban households from six cities in China, this paper estimates the impacts of demographic structure and population aging on household meat consumption, by jointly considering meat consumed at home and away from home. Based on the trajectories of population, a simple simulation on meat demand trend in China is conducted subsequently. The results suggest： 1） Meat consumed away from home averagely accounts for near 30% of household total meat consumption in terms of quantity, so that its omission likely leads to a significant underestimate of total meat consumption and misunderstanding the driving forces; 2） population aging significantly and negatively affects per capita meat consumption, suggesting that the expected meat demand in China without considering population aging will be overestimated. The findings from this study have important implications for better understanding the relative issues on China＇s meat consumption under the situation of population aging.

关键词： capita household consumed income demographic jointly likely surveying estimates proportion

The Prediction of Daily Water Demand based on Fuzzy Neural Network with an Improved Levenberg-Marquardt Algorithm 36

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The Prediction of Daily Water Demand based on Fuzzy Neural N...