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Chinese Science Bulletin 2000年第S1期45卷 21-25页

作者： peng xianzhi JIA Rongfen LI Rongsen DAI Shunying LIU Tungsheng Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640China Wuhan Institute of Virology Chinese Academy of SciencesWuhan 430071China

405 samples were collected from L5-S5-L6 in consideration of obvious variations in susceptibility of the geological sections, which are section Xifeng in Gansu Province and section Duanjiapo in Shaanxi Province for study of magnetotactic bacteria (MB) and magnetosomes (MS) in Chinese loess-paleosol sequences. MB in each sample were observed by TEM after being cultured under 8-18℃, room temperature (RT), 25℃, 26℃ and 30℃ conditions. In general, MB are distributed widely in loess-paleosol sequences, fewer in loess layers with predomination of vibriod in shape. However, there are more MB in paleosol layers with morphological varieties such as roddish, vibriod and occasionally approximately coccus. The magnetosomes (MS) in MB of paleosol are usually arranged in chains along the cells. It was also found that MB growth and MS formation are associated with the environment in which MB live. It can be inferred from the distributions of MB and MS that the paleoclimates fluctuated during the formation of

关键词： loess-paleosol sequences magnetotactic bacteria (MB) magnetosomes (MS) paleoeclimate Section Xifeng Section Duanjiapo.

Analysis of Environmental Endocrine Disrupting Activities in Wastewater Treatment Plant Effluents Using Recombinant Yeast Assays Incorporated with Exogenous Metabolic Activation System

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Biomedical and Environmental Sciences 2011年第2期24卷 132-139页

作者： LI Jian CHEN Ming WANG ZiJian MA Mei peng xianzhi Engineering Research Center of Groundwater Pollution Control and Remediation Ministry of Education College of Water Sciences Beijing Normal University Beijing 100875 China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 Guangdong China

Objective To measure the endocrine disrupting chemicals （EDCs） in wastewater and evaluate the EDCs removal efficiencies in the municipal wastewater treatment plants （WWTP）. Methods A battery of in vitro recombinant yeast bioassays incorporated with exogenous metabolic activation system （rat liver preparation, S9 mix） was conducted to assess the estrogen receptor （ER）, androgen receptor （AR）, progesterone receptor （PR）, and thyroid receptor （TR） ant/agonistic activities of effluents collected from Datansha WWTP. Results The indirect estrogenic, anti‐androgenic, anti‐progesteronic, and anti‐thyroidic activities were observed in the influent. The removal efficiencies of EDCs were above 74%, suggesting that the present wastewater treatment processes were good enough to remove most of these indirect endocrine disrupting chemicals. Conclusion The incorporation of exogenous metabolic capacity into the test system was valid for the study of indirect effects on ER, AR, PR, and TR.

关键词： Recombinant yeast assay Endocrine disrupting chemicals Wastewater sample Metabolic activation

Antibiotics in two municipal sewage treatment plants in Sri Lanka:Occurrence,consumption and removal efficiency

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Emerging Contaminants 2019年第1期5卷 272-278页

作者： Dilanka N.D.Samaraweera Xin Liu Guangcai Zhong Tilak Priyadarshana Riffat Naseem Malik Gan Zhang Mahdi Safaei Khorram Zewen Zhu xianzhi peng Zewen Zhu a Xianzhi Peng a a State Key Laboratory of Organic GeochemistryGuangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou510640China University of Chinese Academy of Sciences Beijing100049China Faculty of Fisheries and Marine Sciences&Technology University of RuhunaMataraSri Lanka Department of Environmental Sciences Quaid-i-Azam UniversityIslamabadPakistan

Most of the monitoring data on the occurrence of antibiotics in sewage treatment plants(STPs)have been reported from Europe,North America and some countries in Northeast Asia,while very limited data can be found in Southeast Asian *** a pioneering research in Sri Lanka,we collected 24 h composite wastewater samples at the influent and effluent of two municipal STPs for consecutive 7 days to investigate occurrence,consumption and removal efficiency of seventeen *** STP was located in Colombo and Hikkaduwa,respectively,representing two kinds of communities(*** and tourists)in Sri *** targeted antibiotics were extracted by solid-phase extraction method and detected on an Agilent HPLCMSMS(1290/6470QQQ).Results illustrated that the majority of the antibiotics can be always detected from both STPs,except for chlorotetracycine(CTC),doxycycline(DOX)and florfenicol(FF).Fluoroquinolones(FQs)were detected at highest concentrations with ciprofloxacin(CIP)being the dominant *** of CIP in the influent samples were in the range of 433 e6010 ng/*** consumption of antibiotics was estimated on the basis of influent mass load and catchment population *** found difference in consumption patterns between the two served *** to local people in Colombo,tourists in Hikkaduwa appeared to take more antibiotics during the study period with the estimated daily dose of 0.25 g per 1000 ***,macrolides accounted for a larger portion than FQs in Hikkaduwa,with azithromycin(AZM)being the most prevalent antibacterial *** comparison with an official report by Medical Supplies Division of Sri Lanka,we conjected that AZM was not commonly used among local people and it was mainly introduced by foreign *** for the removal efficiency,the activated sludge system of Colombo exhibited better elimination and more stable performance than the constructed wetland process of Hikkaduwa.

关键词： Antibiotics Sewage treatment plants(STPs) Activated sludge process Constructed wetland Consumption Removal efficiency Sri Lanka

Polycyclic aromatic hydrocarbon deposition to and exchange at the air-water interface of Luhu, an urban lake in Guangzhou, China

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Chinese Journal Of Geochemistry 2006年第B8期25卷 189-190页

作者： Jun LI Gan ZHANG Shihua QI Lingli GUO xianzhi peng State Key Laboratory of Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China School of Environmental Sciences China University of Geosciences Wuhan 430074 China

Environmental response to ore deposits and mining of the Diaojiang River basin, Guangxi (South China)

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Chinese Journal Of Geochemistry 2006年第B8期25卷 40-41页

作者： Yongzhang ZHOU Zhi DANG xianzhi peng Zhijun YANG Chengbo ZHANG Xiaoqiang YANG Shanming FU Yuyan ZHAO Center for Earth＇s Environment and Resources Zhongshan University Guangzhou 510275 China School of Environment Sciences South China University of Technology Guangzhou 510640 China Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

Time-Periodic Solutions to Quasilinear Hyperbolic Systems on General Networks

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 41-72页

作者： peng QU School of Mathematical Sciences Fudan UniversityShanghai 200433China

For quasilinear hyperbolic systems on general networks with time-periodic boundary-interface conditions with a dissipative structure,the existence and stability of the time-periodic classical solutions are discussed.

关键词： Time-periodic solution Quasilinear hyperbolic system General net-work Classical solution Asymptotic stability

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

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China Foundry 2024年第1期21卷 82-90页

作者： Kun Gao Yan peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting *** effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in *** each rotation,the casting wheel passes through four different spray *** results show that the temperature distribution of the casting wheel in different spray zones is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray zoneⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2 MPa and 1.82 mm,*** temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray zones

Numerical simulation of fluid flow and free surface fluctuations during wheel and belt casting process

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Journal of Iron and Steel Research International 2024年第5期31卷 1117-1126页

作者： Kun Gao Yan peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

The unstable fluid flow and severe free surface fluctuations in the wheel and belt caster can affect the quality of the cast *** lower level height tends to entrap inclusions in the molten *** the other hand,the higher level height makes the production process more dangerous due to the overflow of high temperature fluid from the mold.A computational model of the molten metal pouring process was *** transient fluid flow and free surface fluctuations behavior were calculated using the three-dimensional large eddy simulation model and the volume of fluid *** results show that the flow velocity of the main jet gradually decreases under the influence of the low kinetic energy fluid in the *** is an obvious oscillation in the tail of the jet,while the flow field is asymmetric in *** jet is closer to the inside radius side due to the Coanda effect,and there is a recirculation zone on the inside radius and the outside radius respectively,according to the 10 s time-averaged *** with the industrial observation and simulation results,the shape of the free surface is a wave that varies with *** addition,the free surface height is lowest and the flow velocity is highest in the region near the jet.

关键词： Fluid flow Free surface Wheel and belt caster Large eddy simulation Volume of fluid method

Two-Stage Online Debiased Lasso Estimation and Inference for High-Dimensional Quantile Regression with Streaming Data

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Journal of Systems Science & Complexity 2024年第3期37卷 1251-1270页

作者： peng Yanjin WANG Lei School of Statistics and Data Science KLMDASRLEBPS and LPMCNankai UniversityTianjin 300071China

In this paper,the authors propose a two-stage online debiased lasso estimation and statistical inference method for high-dimensional quantile regression(QR)models in the presence of streaming *** the first stage,the authors modify the QR score function based on kernel smoothing and obtain the online lasso smoothed QR estimator through iterative *** estimation process only involves the current data batch and specific historical summary statistics,which perfectly accommodates to the special structure of streaming *** the second stage,an online debiasing procedure is carried out to eliminate biases caused by the lasso penalty as well as the accumulative approximation error so that the asymptotic normality of the resulting estimator can be *** authors conduct extensive numerical experiments to evaluate the performance of the proposed *** experiments demonstrate the effectiveness of the proposed method and support the theoretical *** application to the Beijing PM2.5 Dataset is also presented.

关键词： Adaptive tuning asymptotic normality debiased lasso online updating quantile regres-sion

Electronic origin of structural degradation in Li-rich transition metal oxides:The case of Li_(2)MnO_(3)and Li_(2)RuO_(3)

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Journal of Semiconductors 2024年第4期45卷 82-86页

作者： peng Zhang Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics andOp toelec-tronic EngineeringShenzhen UniversityShenzhen 518060China

Li_(2)MnO_(3)and Li_(2)RuO_(3)represent two prototype Li-rich transition metal(TM)oxides as high-capacity cathodes for Li-ion batteries,which have similar crystal structures but show quite different cycling ***,based on the first-princi-ples calculations,we systematically studied the electronic structures and defect properties of these two Li-rich cathodes,in order to get more understanding on the structural degradation mechanism in Li-rich TM *** calculations indicated that the structural and cycling stability of Li_(2)MnO_(3)and Li_(2)RuO_(3)depend closely on their electronic structures,especially the energy of their highest occupied electronic states(HOS),as it largely determines the defect properties of these *** Li_(2)MnO_(3)with low-energy HOS,we found that,due to the defect charge transfer mechanism,various defects can form spontaneously in its host structure as Li ions are extracted upon delithiation,which seriously deteriorates its structural and cycling *** for Li_(2)RuO_(3),on the other hand,we identified that the high-energy HOS prevents it from the defect formation upon delithi-ation and thus preserve its cycling *** studies thus illustrated an electronic origin of the structural degradation in Li-rich TM oxides and implied that it is possible to improve their cycling performances by carefully adjusting their TM compo-nents.

关键词： defects Li-ion batteries first-principles calculations