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Characterization of odorous charge and photochemical reactivity of VOC emissions from a full-scale food waste treatment plant in China

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Journal of Environmental Sciences 2015年第3期27卷 34-44页

作者： Zhe Ni Jianguo Liu Mingying Song Xiaowei Wang Lianhai ren xin Kong School of Environment Tsinghua University Key Laboratory for Solid Waste Management and Environment Safety Ministry of Education School of Food and Chemical Engineering Beijing Technology and Business University

Food waste treatment plants （FWTPs） are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound （VOC） emissions. This study investigated the VOC emissions from a selected full-scale FWTP in China. The feedstock used in this plant was mainly collected from local restaurants. For a year, the FWTP was closely monitored on specific days in each season. Four major indoor treatment units of the plant, including the storage room, sorting/crushing room, hydrothermal hydrolysis unit, and aerobic fermentation unit, were chosen as the monitoring locations. The highest mean concentration of total VOC emissions was observed in the aerobic fermentation unit at 21,748.2-31,283.3 μg/m^3, followed by the hydrothermal hydrolysis unit at 10,798.1-23,144.4 μg/m^3. The detected VOC families included biogenic compounds （oxygenated compounds, hydrocarbons, terpenes, and organosulfur compounds） and abiogenic compounds （aromatic hydrocarbons and halocarbons）. Oxygenated compounds, particularly alcohols, were the most abundant compounds in all samples. With the use of odor index analysis and principal components analysis, the hydrothermal hydrolysis and aerobic fermentation units were clearly distinguished from the pre-treatment units, as characterized by their higher contributions to odorous nuisance. Methanthiol was the dominant odorant in the hydrothermal hydrolysis unit, whereas aldehyde was the dominant odorant in the aerobic fermentation unit. Terpenes, specifically limonene, had the highest level of propylene equivalent concentration during the monitoring periods. This concentration can contribute to the increase in the atmospheric reactivity and ozone formation potential in the surrounding air.

关键词： Food waste treatment plant In-situ monitoring VOC emissions Odorous charge Photochemical reactivity

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Geology and mineralization of the Songpan-Ganze-West Kunlun pegmatite-type rare-metal metallogenic belt in China:An overview and synthesis

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Science China Earth Sciences 2023年第8期66卷 1702-1724页

作者： Jiankang LI Peng LI Qinggao YAN Denghong WAng Guangli ren xin DIng MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China Xi’an Center of Geological Survey China Geological SurveyXi’an 710054China School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China

The Songpan-Ganze orogenic belt on the northeastern margin of the Tibetan Plateau extends westward from the Songpan-Ganze terrain in western Sichuan to the Tianshuihai region in West Kunlun,*** hosts numerous giant spodumene pegmatite deposits and ore fields,including Jiajika and Ke’eryin in western Sichuan Province,Zhawulong on the border between the Sichuan and Qinghai Provinces,and Dahongliutan in xinjiang *** form the Songpan-Ganze-West Kunlun(SP-GZ-WK) pegmatite-type rare-metal metallogenic *** pegmatite type rare-metal deposits in this belt are hosted in the metamorphic thermal domes in the metamorphosed flysh of the Triassic Xikang and Bayankalashan *** mineralized pegmatites are intimately related to the Li-and volatile-rich two-mica granites that are peraluminous and have high(Li+Na+K)/(Mn+Fe+Mg+Ca+Ti) *** and granites in individual ore field throughout the belt typically form a cogenetic granite-pegmatite system,in which pegmatite dikes commonly surround *** is the predominant ore mineral in most pegmatites with limited hydrothermal *** the granite-pegmatite systems,granitic magmas were emplaced under P-T conditions of 800–850°C and ~550 MPa,while spodumene crystallized in an alkaline *** granite-pegmatite systems share similar Sr-Nd-Hf-Li isotopic compositions to the metasediments of the Xikang and Bayankalashan *** δ7Li values tend to increase from the granites to the Li-poor pegmatites,whereas the reverse is observed between the Li-poor and Li-rich *** geochronological data suggest that the granite-pegmatite systems formed in the Late Triassic and tend to be progressively younger from the outer to the inner zones of the metallogenic *** characteristics show that the granitic-pegmatitic melts were derived from the anatexis of the Xikang and Bayankalashan Groups during the Paleo-Tethyan orogeny in the Late *** separation of pegmatitic melts

关键词： Songpan-Ganze-West Kunlun metallogenic belt Rare-metal deposit Granitic pegmatite Spodumene Metallogenic regularity

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Characteristics of Water Infiltration in Layered Water-Repellent Soils

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Pedosphere 2018年第5期28卷 775-792页

作者： LI Yi ren xin Robert HILL Robert MALONE ZHAO Ying College of Water Resources and Architecture Engineering Northwest A&F University Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F University Department of Environmental Science and Technology University of Maryland USDA-ARS National Laboratory for Agriculture and the Environment Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of AgricultureNorthwest A&F University

Water-repellent(WR) soil greatly influences infiltration behavior. This research determined the impacts of WR levels of silt loam soil layer during infiltration. Three column scenarios were utilized, including homogeneous wettable silt loam or sand, silt loam over sand(silt loam/sand), and sand over silt loam(sand/silt loam). A 5-cm thick silt loam soil layer was placed either at the soil surface or 5 cm below the soil surface. The silt loam soil used had been treated to produce different WR levels, wettable, slightly WR, strongly WR, and severely WR. As the WR level increased from wettable to severely WR, the cumulative infiltration decreased. Traditional wetting front-related equations did not adequately describe the infiltration rate and time relationships for layered WR soils. The Kostiakov equation provided a good fit for the first infiltration stage. Average infiltration rates for wettable, slightly WR, strongly WR, and severely WR during the 2 nd infiltration stage were 0.126, 0.021, 0.002, and 0.001 mm min^(-1) for the silt loam/sand scenario,respectively, and 0.112, 0.003, 0.002, and 0.000 5 mm min^(-1) for the sand/silt loam scenario, respectively. Pseudo-saturation phenomena occurred when visually examining the wetting fronts and from the apparent changes in water content(?θ_(AP)) at the slightly WR,strongly WR, and severely WR levels for the silt loam/sand scenario. Much larger ?θAPvalues indicated the possible existence of finger flow. Delayed water penetration into the surface soil for the strongly WR level in the silt loam/sand scenario suggested negative water heads with infiltration times longer than 10 min. The silt loam/sand soil layers produced sharp transition zones of water content. The WR level of the silt loam soil layer had greater effects on infiltration than the layer position in the column.

关键词： infiltration model layered soils ponded infiltration experiment pseudo-saturation soil water content soil water move-ment soil water repellency water drop penetration time

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Numerical study on the turbulent mixing of planar shock-accelerated triangular heavy gases interface

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Acta Mechanica Sinica 2018年第5期34卷 855-870页

作者： Wei-Gang Zeng Jian-Hua Pan Yu-xin ren Yu-Tao Sun Department of Engineering Mechanics School of AerospaceTsinghua UniversityBeijing 100084China Institute of Applied Physics and Computational Mathematics Beijing 100094China

The interaction of a planar shock wave with a triangle-shaped sulfur hexafluoride (SF6) cylinder surrounded by air is numerically studied using a high resolution finite volume method with minimum dispersion and controllable dissipation *** vortex dynamics of the Richtmyer-Meshkov instability and the turbulent mixing induced by the KelvinHelmholtz instability are discussed.A modified reconstruction model is proposed to predict the circulation for the shock triangular gas-cylinder interaction *** typical stages leading the shock-driven inhomogeneity flow to turbulent mixing transition are *** the decoupled length scales and the broadened inertial range of the turbulent kinetic energy spectrum in late time manifest the turbulent mixing transition for the present *** analysis of variable-density energy transfer indicates that the flow structures with high wavenumbers inside the Kelvin-Helmholtz vortices can gain energy from the mean flow in ***,small scale flow structures are generated therein by means of nonlinear ***,the occasional 'pairing' between a vortex and its neighboring vortex will trigger the merging process of vortices and,finally,create a large turbulent mixing zone.

关键词： Richtmyer-Meshkov instability Kelvin-Helmholtz instability Length scale Turbulent mixing

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Additive effects on tin electrodepositing in acid sulfate electrolytes

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International Journal of Minerals,Metallurgy and Materials 2013年第5期20卷 472-478页

作者： Fa-xin Xiao Xiao-ni Shen Feng-zhang ren Alex A. Volinsky School of Materials Science and Engineering Henan University of Science and Technology Department of Mechanical Engineering University of South Florida

The effects of additives on the stannous reduction of an acid sulfate bath were investigated using cyclic and linear sweep voltammetry, electrochemical impedance spectroscopy （EIS）, and microstructure analysis. In the absence of additives, tin coatings are rough, and the tin electrodepositing is a single-step reduction process accompanied by hydrogen gas evolution. The addition of tartaric acid produces a slight reduction in the peak current of stannous reduction and has an appreciably positive effect on the stability of the acidic tin bath. Both benzylidene acetone and polyoxyethylene octylphenol ether hinder the stannous reduction and greatly suppress the hydrogen gas evolution. Formaldehyde slightly decreases the peak current density of stannous reduction and serves as an auxiliary brightener in the acid sulfate bath. The presence of mixed additives greatly suppresses the stannous reduction and hydrogen gas evolution and consequently produces a significantly smoother and denser tin coating. The （112） crystal face is found to be the dominant and preferred orientation of tin deposits.

关键词： electrodepositing tin additives stannous reductiOn

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Terahertz radiation of a butterfly-shaped photoconductive antenna(invited)

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红外与激光工程 2019年第4期48卷 9-17页

作者： Jitao Zhang Mingguang Tuo Min Liang Wei-ren ng Michael E.Gehm Hao xin Department of Electrical and Computer Engineering University of Arizona Fischell Department of Bioengineering University of Maryland Department of Electrical and Computer Engineering Duke University

The terahertz(THz) far-field radiation properties of a butterfly-shaped photoconductive antenna(PCA) were experimentally studied using a home-built THz time-domain spectroscopy(THz-TDS) *** distinguish the contribution of in-gap photocurrent and antenna structure to far-field radiation,polarization-dependent THz field was measured and quantified as the illuminating laser beam moved along the bias field within the gap region of electrodes. The result suggests that, although the far-field THz radiation originates from the in-gap photocurrent, the antenna structure of butterfly-shaped PCA dominates the overall THz radiation. In addition, to explore the impact of photoconductive material,radiation properties of butterfly-shaped PCAs fabricated on both low-temperature-grown GaAs(LT-GaAs) and semi-insulating GaAs(Si-GaAs) were characterized and compared. Consistent with previous experiments, it is observed that while Si-GaAs-based PCA can emit higher THz field than LT-GaAs-based PCA at low laser power, it would saturate more severely as laser power increased and eventually be surpassed by LT-GaAs-based PCA. Beyond that, it is found the severe saturation effect of Si-GaAs was due to the longer carrier lifetime and higher carrier mobility, which was confirmed by the numerical simulation.

关键词： terahertz photoconductive antenna butterfly time domain spectroscopy

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Molecular characterization and expression analysis of three homoeologous Ta14S genes encoding 14-3-3 proteins in wheat(Triticum aestivum L.)

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The Crop Journal 2016年第3期4卷 188-198页

作者： xinguo Wang Yanli Wang Ruixia Xiao xin Chen Jiangping ren National Wheat Engineering Research Center Agricultural University of Henan

The purpose of this study was to characterize Ta14 S homoeologs and assess their functions in wheat seed *** genomic and c DNA sequences of three Ta14 S homoeologous genes encoding 14-3-3 proteins were *** analysis revealed that the three homoeologs consisted of five exons and four introns and were very highly conserved in the coding regions and in exon/intron structure,whereas the c DNA sequences were variable in the 5′ and 3′-*** three genes,designated as Ta14S-2A,Ta14S-2B and Ta14S-2D,were located in homoeologous group 2 *** polypeptide chains of the three Ta14 S genes were highly *** genes were most homologous to Hv14 A from ***-time quantitative PCR indicated that the three Ta14 S genes were differentially expressed in different organs at different developmental stages and all exhibited greater expression in primary roots of 1-day-old germlings than in other *** of the expression patterns of the three homoeologous genes at different times after pollination also revealed that their expression was developmentally *** transcription of Ta14S-2B was clearly higher during seed germination,whereas expressions of Ta14S-2A and Ta14S-2D were up-regulated at the beginning of seed imbibition(0–12 h),but declined *** results suggested that the three Ta14 S homoeologous genes have regulatory roles in seed development and germination.

关键词： Common wheat Gene expression Homoeologous genes Developmental regulation

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Microstructure characterization of a pressureless infiltrating oxidized SiCp preform by Al-8Mg

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International Journal of Minerals,Metallurgy and Materials 2011年第2期18卷 223-228页

作者： Shu-bin ren Xiao-yu Shen xin-bo He Xuan-hui Qu School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The microstructure of a pressureless infiltrating 55vol% oxidized SiC preform by Al-8Mg alloy was characterized by transmission electron microscopy （TEM）, high resolution TEM （HRTEM）, field emission scanning electron microscopy （FE-SEM）, and X-ray diffraction. The TEM image of the interface between Al and SiC shows that the surface of SiC is covered by a rough nanocrystal layer of MgAl2O4, Al2O3, and Si, produced by the interfacial reaction of Al, Mg, and SiO2 on the surface of SiC. The Al-SiC interface is also examined by HRTEM to be better understood how MgAl2O4 and Al2O3 are produced. Dendritic Al2O3 crystals are embedded in the pores of the composite generated from the mutual bonding of SiO2 on the surface of SiC. Columnar AlN crystals of about 250 nm in length are bunched vertically on the SiC particle surface.

关键词： microstructure composites interfaces pressureless infiltration oxidation.

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Effect of Mg and Si on infiltration behavior of Al alloys pressureless infiltration into porous SiCp preforms

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 703-708页

作者： Shu-bin ren Xiao-yu Shen Xuan-hui Qu xin-bo He School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The effect of Mg and Si additon to Al matrix on infiltration kinetics and rates of Al alloys pressureless infiltration into porous SiCp preform was investigated by observing the change of infiltration distance with time as the Al alloys infiltrate into SiCp preforms at different *** results show that infiltration of SiCp preforms by Al melt is a thermal activation process and there is an incubation period before the infiltration becomes *** the increase of Mg content in the Al alloys from 0wt% to 8wt%,the infiltration will become much easier,the incubation period becomes shorter and the infiltration rate is faster,but these effects are not obvious when the Mg content is higher than 8wt%.As for Si addition to the Al alloys,it has no obvious effect on the incubation period,but the infiltration rate increases markedly with the increase of Si content from 0wt% to 12wt% and the rate has no obvious change when the content is bigger than 12wt%.The effect of Mg and Si on the incubation period is related to the infiltration mechanism of Al pressureless infiltration into SiCp preforms and their impact on the infiltration rate is a combined result from viscosity and surface tension of Al melt and SiC-Al wetting ability.

关键词： metallic matrix composites infiltration aluminum alloys silicon carbide preforms

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Artificial Intelligence Meets Chinese Medicine

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Chinese Journal of Integrative Medicine 2019年第9期25卷 648-653页

作者： GUO Yan ren Xue CHEN Yu-xin WAng Teng-jiao Xiyuan Hospital China Academy of Chinese Medicinal Sciences Beijing 100091 China Department of Pediatrics Jinan Municipal Hospital of Traditional Chinese Medicine Jinan 250012 China School of Electrical Engineering and Computer Sciences Peking University Beijing China

As an interdisciplinary subject of medicine and artificial intelligence, intelligent diagnosis and treatment has received extensive attention. The standardization of Chinese medicine(CM) diagnosis has been always a bottleneck in the modernization and globalization of CM. Studying the application technology of artificial intelligence in CM and solving the problems is an urgent need for the development of modern CM in the era of artificial intelligence. Taking the pneumonia with dyspnea and cough in CM as an example, this article gives an overview of intelligent medical technology and application development, brings forward the present technical problems faced and the new advances in intelligent technology on CM diagnosis and treatment.

关键词： artificial intelligence Chinese medicine diagnosis and treatment

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