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Pollution characteristics of 15 gas- and particle-phase phthalates in indoor and outdoor air in Hangzhou

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Journal of Environmental Sciences 2019年第12期31卷 107-119页

作者： Xingzi Ouyang Meng Xia Xueyou Shen Yu Zhan College of Environmental&Resource Sciences Zhejiang UniversityHangzhouZhejiang 310058China Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control HangzhouZhejiang 310058China Department of Environmental Science and Engineering Sichuan UniversityChengduSichuan 610065China

Phthalate esters(PAEs),typical pollutants widely used as plasticizers,are ubiquitous in various indoor and outdoor environments.PAEs exist in both gas and particle phases,posing risks to human health.In the present study,we chose four typical kinds of indoor and outdoor environments with the longest average human residence times to assess the human exposure in Hangzhou,including newly decorated residences,ordinary residences,offices and outdoor air.In order to analyze the pollution levels and characteristics of 15 gasand particle-phase PAEs in indoor and outdoor environments,air and particulate samples were collected simultaneously.The total PAEs concentrations in the four types of environments were 25,396,25,466.8,15,388.8 and 3616.2 ng/m^3,respectively.DEHP and DEP were the most abundant,and DMPP was at the lowest level.Distinct variations in the distributions of indoor/outdoor,gas/particle-phase and different molecular weights of PAEs were observed,showing that indoor environments were the main sources of PAEs pollution.While most PAEs tended to exsit in indoor sites and gas-phase,the high-molecular-weight chemicals tended to exist in the particle-phase and were mainly found in PM2.5.PAEs were more likely adsorbed by small particles,especially for the indoor environments.There existed a good correlation between the particle matter concentrations and the PAEs levels.In addition,neither temperature nor humidity had obvious effects on the distributions of the PAEs concentrations.

关键词： Phthalate esters Indoor and outdoor air Gas and particle phase Distribution characteristics Particles

Optimization of Mineralization Curing System for Efficient and Safe Utilization of Steel Slag Wastes

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Journal of Wuhan University of Technology(Materials Science) 2022年第4期37卷 595-602页

作者：伊海赫 zhan Qiwei yu Xiaoniu School of Civil and Architectural Engineering Shandong University of TechnologyZibo 255000China School of Civil Engineering and Architecture Jiangsu University of Science and TechnologyZhenjiang 212003China Department of Civil and Environmental Engineering Nanyang Technological UniversitySingapore City 639798Singapore

The crystal structure and morphology of the mineralization products were studied by scanning electron microscopy(SEM)and X-ray diffraction(XRD),and the thermal properties were studied by thermogravimetric-differential scanning calorimetry(DSC)analysis.The changes of microorganism quantity and enzyme activity in pore solution with time were measured.The experimental results show that microorganism quantity and enzyme activity in pore solution reach the maximum at 50-60 h,mineralization curing begins at this time,the strength of microbial mineralized steel slag reaches the maximum.This study provides a good selection basis for selecting the optimum mineralization system for the production of microbial mineralized steel slag products.Bacterial mineralization can accelerate the rate of carbon sequestration in the mineralization process.The compressive strength of steel slag with 1.5% bacterial can reach up to 55.6 MPa.The microstructure and thermal properties of calcium carbonate precipitate induced by the enzymes of bacillus subtilis differs from the chemical precipitation in pore solution of steel slag.Through the analysis of the mineralized products of steel slag,the reaction rate of free calcium oxide and free magnesium oxide in steel slag after the addition of microorganisms is significantly increased,which improves the stability of steel slag as cementitious material.Meanwhile,the production of calcium carbonate,the main mineralized product,is significantly increased.

关键词： steel slag microorganism bio-mineralization enzyme activity curing system

Effects of the Resident Basic Medical Insurance Reform on Household Consumption in China

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China & World Economy 2024年第1期32卷 96-129页

作者： Shuheng yu Xinxin Ma Peng zhan School of Public Affairs Institute for Common Prosperity and DevelopmentZhejiang UniversityChina Faculty of Economics Hosei UniversityJapan

This paper investigates the causal relationship between the Urban and Rural Resident Basic Medical Insurance(URRBMI)reform and household consumption in urban China using data from the Chinese Household Income Project survey and employing combination of the propensity score matching and difference-in-differences methods.The results yield three conclusions.First,the reform affected both the amount and share of household consumption.Specifically,the reform led to an increase in total household consumption,encompassing both medical and nonmedical expenditures.Among these,the proportion of medical consumption increased,while the proportion of nonmedical consumption reduced.Second,the impact of the URRBMI reform varied across consumption categories within nonmedical expenditure.Specifically,consumption for education and entertainment industries are positively impacted by the URRBMI reform in terms of both quantity and proportion.Third,low-income households benefit more from the URRBMI reform compared to middle-and high-income households.The main channels through which the URRBMI reform affects household consumption were the price effect and the crowding out effect on precautionary savings.

关键词： household consumption nonmedical consumption out-of-pocket expenses reimbursement ratio

Evolutionary Computation for Expensive Optimization:A Survey

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Machine Intelligence Research 2022年第1期19卷 3-23页

作者： Jian-yu Li Zhi-Hui zhan Jun zhang School of Computer Science and Engineering South China University of TechnologyGuangzhou 510006China Pazhou Laboratory Guangzhou 510330China Victoria University Melbourne 8001Australia

Expensive optimization problem(EOP) widely exists in various significant real-world applications. However, EOP requires expensive or even unaffordable costs for evaluating candidate solutions, which is expensive for the algorithm to find a satisfactory solution. Moreover, due to the fast-growing application demands in the economy and society, such as the emergence of the smart cities, the internet of things, and the big data era, solving EOP more efficiently has become increasingly essential in various fields, which poses great challenges on the problem-solving ability of optimization approach for EOP. Among various optimization approaches, evolutionary computation(EC) is a promising global optimization tool widely used for solving EOP efficiently in the past decades. Given the fruitful advancements of EC for EOP, it is essential to review these advancements in order to synthesize and give previous research experiences and references to aid the development of relevant research fields and real-world applications. Motivated by this, this paper aims to provide a comprehensive survey to show why and how EC can solve EOP efficiently. For this aim, this paper firstly analyzes the total optimization cost of EC in solving EOP. Then, based on the analysis, three promising research directions are pointed out for solving EOP, which are problem approximation and substitution, algorithm design and enhancement, and parallel and distributed computation. Note that, to the best of our knowledge, this paper is the first that outlines the possible directions for efficiently solving EOP by analyzing the total expensive cost. Based on this, existing works are reviewed comprehensively via a taxonomy with four parts, including the above three research directions and the real-world application part. Moreover, some future research directions are also discussed in this paper. It is believed that such a survey can attract attention, encourage discussions, and stimulate new EC research ideas for solving EOP and related real-world applicatio

关键词： Expensive optimization problem evolutionary computation evolutionary algorithm swarm intelligence particle swarm optimization differential evolution

Iodomethane as an organocatalyst for the aerobic ortho-selective trifluoromethylation of pyridines

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Science China Chemistry 2023年第1期66卷 133-138页

作者： Jianjin yu Renqin zhan Chao-Jun Li Huiying Zeng State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou University.Lanzhou 730000China Department of Chemistry FQRNT Centre for Green Chemistry and CatalysisMcGll UniversityMontrealOuebec H3A OB8Canada

Iodomethane is usually used as an electrophilic methylation reagent.Herein,we report its use as a C1 organocatalyst for the aerobic ortho-selective trifluoromethylation of pyridines in the absence of a transition metal.Trifluoroacetic acid(TFA)was employed as an inexpensive,readily available trifluoromethyl source.The reaction efficiently produced a variety of trifluoromethylation products,with good functional group compatibility.Pyridine-containing drug molecules could also be selectively trifluoromethylated for late-stage functionalizations.Mechanistic studies showed that iodomethane selectively reacted with the pyridine starting material,rather than the pyridine product,to generate the corresponding N-methylpyridinium iodide.The decarboxylation of trifluoroacetic acid produced a trifluoromethyl anion,which added to the methylpyridinium iodide,and the subsequent aerobic rearomatization led to the generation of the ortho-trifluoromethylated product.

关键词： iodomethane-catalysis trifluoromethylation pyridines transition-metal-free trifluoroacetic acid

Thermodynamic Performance Comparison and Optimization of sCO_(2)Brayton Cycle,tCO_(2)Brayton Cycle and tCO_(2)Rankine Cycle

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Journal of Thermal Science 2023年第2期32卷 611-627页

作者： JIANG yu zhan Li TIAN Xuelian NIE Changhua Nuclear Power Institute of China Chengdu 610213China

In this paper,to further improve thermodynamic performance of supercritical carbon dioxide cycle,simple/recompression transcritical carbon dioxide Brayton cycle(STBC/RTBC)and simple/recompression transcritical carbon dioxide Rankine cycle(STRC/RTRC)are proposed.Thermal and exergy performance analysis and optimization for the above four transcritical CO_(2)cycles and simple/recompression supercritical cycle(SSBC/RSBC)are conducted.The effect of key thermodynamic parameters on those CO_(2)cycle performance is studied.Results indicate that the improvements of thermodynamic performance of CO_(2)cycle are obvious when transcritical Brayton and Rankine cycle are applied in it.Within the same range of optimization variables,the maximum thermal efficiency improvements of RTRC and RTBC are 4.98%and 3.6%,and maximum exergy efficiency improvements of RTRC and RTBC are 7.08%and 5.13%when compared with RSBC.Moreover,the thermodynamic performances of STBC and STRC are also outstanding than that of SSBC.This work provides a way to further improve the thermodynamic performance of CO_(2)power cycle.

关键词： thermodynamic performance supercritical carbon dioxide transcritical carbon dioxide Brayton cycle Rankine cycle

Preparation of Low Cost Activated Carbon from Deactivated Resin Catalyst for Methyl Tert-Butyl Ether Synthesis and Its Application in Dimethyl Sulfide Adsorption with Transition Metal Impregnation

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China Petroleum Processing & Petrochemical Technology 2017年第2期19卷 55-64页

作者： Yu Zhan Shi Li Meng Xuan The State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai 200237

In this paper, a low-cost activated carbon(AC) was prepared from deactivated resin catalyst(DRC) for methyl tert-butyl ether(MTBE) synthesis through carbonization and subsequent steam activation treatment. The activated carbon was characterized in detail. After loading various transition metals, including Cu^(2+), Ag+, Co^(2+), Ni^(2+), Zn^(2+), and Fe^(3+) via the ultrasonic-assisted impregnation method, a series of metal-loaded adsorbents(xM-AC) were obtained and their dimethyl sulfide(DMS) adsorption performance was investigated in a batch system. Among these adsorbents, 15Cu-AC presented a superior DMS adsorption capacity equating to 58.986 mg/g due to the formation of S-M(σ) bonds between Cu^(2+) and sulfur atoms of DMS as confirmed by the Raman spectra and kinetic study.

关键词： activated carbon deactivated resin catalyst dimethyl sulfide transition metal

Occupational exposure assessment of phthalate esters in indoor and outdoor microenvironments

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Journal of Environmental Sciences 2018年第10期30卷 75-88页

作者： Meng Xia Xingzi Ouyang Xueqing Wang Xueyou Shen Yu Zhan College of Environmental & Resource Sciences Zhejiang UniversityHangzhou Zhejiang 310058 China Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control Hangzhou Zhejiang 310058 China

Phthalate esters（PAEs） are widely used as plasticizers in consumer products. PAEs are a group of environmental hormone which disrupts human and animals＇ endocrine systems. Different occupational groups are exposed to various levels of PAEs. In the present study, four typical occupational groups were chosen, including doctors, college teachers, college students, and drivers who worked in public traffic system. In order to understand the exposure levels to PAEs via inhalation, air samples were collected from multiple microenvironments including indoor and outdoor in Hangzhou to measure the gas and particle concentrations of six PAEs, together with time spent in different microenvironments of these four groups. A comprehensive PAEs exposure model was built to estimate the daily PAEs exposure through inhalation, oral and dermal pathways. The Monte Carlo simulation results show that doctors were exposed to the highest level of PAEs, and consequently had the highest health risk among these four occupational groups. In contrast, college students had the lowest health risk. By setting the exposure level of staying in residences as the baseline, doctors and drivers were two occupations exposed to high PAEs health risk. Di-（2-ethylhexyl） phthalate（DEHP） was the largest contributor among the six phthalates, posing moderate health risk（10-5–10-6） to every occupation. For traffic microenvironments alone, the total exposure levels for different transportation modes were in the descending order of busses, cars, cabs, tubes, motor bikes, and walking.

关键词： Phthalate esters Microenvironment Occupation Exposure assessment Uncertainty analysis

Rapidly modifying microstructure and mechanical properties of AA7150 Al alloy processed with electropulsing treatment

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Journal of Materials Science & Technology 2021年第36期95卷 172-179页

作者： Kai Chen Lihua zhan Wenfang yu College of Mechanical and Electrical Engineering of Central South University Changsha 410083China State Key Laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083China Light Alloy Research Institute of Central South University Changsha 410083China

Studies show that the proper solid solution treatment(SST)is a key step in the precipitation strengthening of AA7150 Al alloy.Despite the superior characteristics of the fully dissolved phase,it has major drawbacks,including high consumption of energy and low efficiency.Recently,electropulsing treatment(EPT)has been proposed to study dissolved precipitations and modify microstructures of AA7150 Al alloy faster than conventional SST.Experiments have been conducted in the present article,and the obtained results show that EPT can promote the rapid dissolution of theη’phase at relatively low temperatures in only 20 s.Meanwhile,the strength and ductility of electropulsed samples decrease drastically.Compared with conventional SST,EPT accelerates recrystallization and obtains relatively fine grains after 20 and 50 s electric pulses.Moreover,as the EPT time increases,the corresponding non-uniform local heating and the electron force promote dislocation generation and annihilation.

关键词： AA7150 Al alloy Electropulsing treatment Rapid dissolution Recrystallization Dislocation