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Stability behavior of the Lanxi ancient flood control levee after reinforcement with upside-down hanging wells and grouting curtain

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Journal of Mountain Science 2024年第1期21卷 84-99页

作者： QIN Zipeng TIAN Yan GAO Siyuan ZHOU Jianfen HE Xiaohui HE Weizhong GAO Jingquan School of Water conservancy and environment engineering Zhejiang University of Water Resources and Electric PowerHangzhou 310018China Department of Civil engineering Imperial College LondonLondonSW71BFEngland Lanxi Water Affairs Bureau Lanxi 321102China Zhejiang Water conservancy engineering consulting co. LtdHangzhou 310051China

The stability of the ancient flood control levees is mainly influenced by water level fluctuations, groundwater concentration and rainfalls. This paper takes the Lanxi ancient levee as a research object to study the evolution laws of its seepage, displacement and stability before and after reinforcement with the upside-down hanging wells and grouting curtain through numerical simulation methods combined with experiments and observations. The study results indicate that the filled soil is less affected by water level fluctuations and groundwater concentration after reinforcement. A high groundwater level is detrimental to the levee's long-term stability, and the drainage issues need to be fully considered. The deformation of the reinforced levee is effectively controlled since the fill deformation is mainly borne by the upside-down hanging wells. The safety factors of the levee before reinforcement vary significantly with the water level. The minimum value of the safety factors is 0.886 during the water level decreasing period, indicating a very high risk of the instability. While it reached 1.478 after reinforcement, the stability of the ancient levee is improved by a large margin.

关键词： Stability analysis Multiple factors Antiseepage reinforcement Upside-down hanging well Grouting curtain Ancient levee

Mechanism study of Cu(Ⅱ) adsorption from acidic wastewater by ultrasonic-modified municipal solid waste incineration fly ash

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Chinese Journal of Chemical engineering 2024年第3期67卷 157-165页

作者： Shunda lin Yang Lu Lin Zheng Ling Long Xuguang Jiang Jianhua Yan State Key Laboratory of Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou 310027China Zhejiang University Qingshanhu Energy Research Center Hangzhou 310027China hangzhou Xiaoshan Jinjiang Green Energy co. Ltd.XiaoshanHangzhou 310000China

High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(MSWI) fly ash for Cu(Ⅱ) adsorption to achieve the purpose of “treating waste by waste.” The effects of p H, adsorption time, initial concentration, and temperature on the modified MSWI fly ash’s adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(Ⅱ) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg.g-1. Additionally, the adsorption process is spontaneous,endothermic, and chemisorption-dominated from the thermodynamic studies(ΔH and ΔS > 0, ΔG < 0).Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(Ⅱ) may be attributed to electrostatic interaction and chelation effects.

关键词： Ultrasound MSWI fly ash Cu(Ⅱ) Wastewater Adsorption

Polymer-encapsulated metal complex catalysts:An emerging and efficient platform for electrochemical co_(2) reduction

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Journal of Materials Science & Technology 2024年第5期172卷 33-50页

作者： Yingshuo Liu Shuaishuai Lyu Fuli Wen Weixuan Nie Shuqing Wang Sinopec Research Institute of Petroleum Processing co. Ltd.Beijing 100083China School of engineering Westlake UniversityHangzhou 310024China

Over the past decade,electrocatalytic reduction of co_(2)has gained substantial ***,hardly any of the previous reviews have focused on the systematic discussion of polymer-molecular catalyst composites as an emerging system for the electrochemical transformation of co_(2)to value-added *** this review,we first give a brief overview of the general features of solid-state and molecular catalysts,and then advance the discussion to polymer-catalyst composite systems,with particular emphasis on polymer-encapsulated molecular catalysts,where the coordination environment surrounding molecular catalysts can be modified via polymer encapsulation to promote the overall performance of co_(2)*** elucidation of the possible reaction mechanisms of this emerging electrocat-alytic system along with proposed optimization strategies is also summarized and discussed based on recently published reports,followed by the challenges and prospects of their industrial applications at the end of this *** this review,we hope the audience can gain a comprehensive understanding of the electrocatalytic mechanism of the coordinating polymers and valuable insights into engineering the microenvironment surrounding the metal complexes for potential future research directions.

关键词： Polymer-molecular catalyst composite Polymer encapsulation coordination environment co_(2)electrocatalysis Electrocatalytic mechanism

Study on the fast elimination of smoke particle based on electro-acoustic coupling agglomeration technology

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Particuology 2024年第5期88卷 1-10页

作者： Jie Feng Mingfeng Lu Kaige Wang Kun Luo Mingzhou Yu Guangxue Zhang Jiangrong Xu Shuping Pan Hailin Gu The Institute for Energy engineering China Jiliang UniversityHangzhou310018China State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou310027China Qingshanhu Energy Research Center Zhejiang UniversityHangzhou310017China Zhejiang Ecological environment Monitoring Center Hangzhou310012China

Fire smoke,which consists large amounts of fine particles,is considered as the fatal factor in *** this study,a fast smoke particle elimination method based on electro-acoustic coupling agglomeration technology is ***,the experimental results show that the electro-acoustic coupling agglomeration has higher smoke elimination efficiency compared to *** smoke transmission is much less than 80%after 30s of single acoustic or electric field action,while the coupled field reaches 90%.Then,the effects of acoustic frequency,sound pressure level and voltage on the smoke elimination characteristics are *** is found that the optimal acoustic frequency is *** as the sound pressure level and voltage increase,the elimination efficiency first increases and then tends to stabilize,the critical values of the sound pressure level and voltage are 135 dB and *** indicates that there is an optimal combination of the three ***,through the theoretical analysis of particle movement and the micro-morphology of agglomerates,the particle agglomeration mechanism under the electro-acoustic coupling is *** study provides a new idea for the fast elimination of fire smoke particle.

关键词： Smoke particle Agglomeration Electro-acoustic coupling Smoke elimination

Defective Nickel-Iron Layered Double Hydroxide for Enhanced Photocatalytic NO Oxidation with Significant Alleviation of NO2 Production

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engineering 2024年第5期36卷 276-284页

作者： Xiaoyu Li Xiaoshu Lv Jian Pan Peng Chen Huihui Peng Yan Jiang Haifeng Gong Guangming Jiang Li’an Hou engineering Research Center for Waste Oil Recovery Technology and Equipment Ministry of EducationChongqing Technology and Business UniversityChongqing 400067China State Key Laboratory of Water environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China environmental Technology Innovation Center of Jiande Hangzhou Bertzer Catalyst Co.Ltd.Hangzhou 310058China Chongqing Key Laboratory of Green Synthesis and Application College of ChemistryChongqing Normal UniversityChongqing 401331China

Photocatalysis offers a sustainable means for the oxidative removal of low concentrations of NOx(NO,NO2,N2O,N2O5,etc.)from the *** double hydroxides(LDHs)are promising candidate photocatalysts owing to their unique layered and tunable chemical structures and abundant surface hydroxide(OH)moieties,which are hydroxyl radical(OH)***,the practical applications of LDHs are limited by their poor charge-separation ability and insufficient active ***,we developed a facile N_(2)H_(4)-driven etching approach to introduce dual Ni^(2+)and OHvacancies(Niv and OHv,respectively)into NiFe-LDH nanosheets(hereafter referred to as NiFe-LDH-et)to facilitate improved charge-carrier separation and active Lewis acidic site(Fe^(3+)and Ni^(2+)exposed at OHv)*** contrast to inert pristine LDH,NiFe-LDH-et actively removed NO under visible-light ***,Ni_(76)Fe_(24)-LDH-et etched with 1.50 mmol·L^(-1)N_(2)H_(4)solution removed 32.8%of the NO in continuously flowing air(NO feed concentration:500 parts per billion(ppb))under visible-light illumination,thereby outperforming most reported *** and theoretical data revealed that the dual vacancies promoted the production of reactive oxygen species(O_(2)·^(-)andOH)and the adsorption of NO on the *** situ spectroscopy demonstrated that NO was preferentially adsorbed at Lewis acidic sites,particularly exposed Fe^(3+)sites,converted into NO+,and subsequently oxidized to NO3without the notable formation of the more toxic intermediate NO2,thereby alleviating risks associated with its production and emission.

关键词： Vacancie Layered double hydroxide NO+ Photocatalysis NO removal

Identification of the optimal doping position of hetero-atoms in chalcogen-doped Fe-N-C catalysts for oxygen reduction reaction

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Particuology 2024年第6期89卷 99-108页

作者： Weihao Liu Huanhuan He Qingtao Liu Xin Wan Jianglan Shui School of Materials Science and engineering Beihang UniversityBeijing100191China School of Space and environment Beihang UniversityBeijing102206China Tianmushan Laboratory Hangzhou310023China

The excellent oxygen reduction reaction(ORR)activity of Fe–N–C catalysts in acidic media makes them potential for low-cost proton exchange membrane fuel *** recent years,it has been shown that heteroatoms(B,O,S,P,Cl,F,etc.)can be used as electron-withdrawing groups to modulate the planar structure and electron distribution of the Fe–Nx active sites to achieve simultaneous improvement of catalytic activity and ***,the optimal location of the heteroatoms remains ***,taking chalcogen heteroatoms(S and Se)as an example,we control the doping positions and investigate their effect on the ORR performance of the Fe–N–C *** first coordination shell of the iron single atom is identified as the optimal doping *** optimized catalysts Fe–N_(3)Se_(1)/NC and Fe–N_(3)Se_(1)/NC demonstrate improved activity and stability in both half cells and fuel *** work provides insights into the enhancement mechanism of heteroatom doping in single-atom catalysts.

关键词： Oxygen reduction reaction Fe-N-C catalysts Hetero-atom doping Doping position Enhancement mechanism

Reducing children’s exposure to di(2-ethylhexyl)phthalate in homes and kindergartens in China:Impact on lifetime cancer risks and burden of disease

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Building Simulation 2024年第3期17卷 431-440页

作者： Dongsheng Tao Wen Sun Donghui Mo Yonghui Lin Wei Lv Daniel Mmereki Yousheng Xu Yanghui Ye Yuanjun Tang Chao Ye cong Dong Zhongming Bu Zhejiang Ecowell Energy Management Technology co. LtdHangzhouChina Department of Energy and environmental System engineering Zhejiang University of Science and TechnologyHangzhouChina Faculty of Health Sciences School of Clinical MedicineUniversity of the WitwatersrandParktown2193JohannesburgSouth Africa

Exposure to di(2-ethylhexyl)phthalate(DEHP)in the indoor environment has been linked with significant health risks for Chinese ***-phase DEHP concentrations in Chinese residences and kindergartens were estimated using a mass balance model based on the current baseline condition and control strategies(i.e.,increasing ventilation rate,reducing area of sources,using mechanical ventilation systems,and using portable air cleaners).The health benefits of each control strategy were quantified as the reduction in lifetime cancer risks(LCR)and burden of disease(BoD).In the current situation,the mean LCR and disability-adjusted life years(DALY)number attributable to indoor DEHP exposure for Chinese children were around 6.0×10^(−6) and 155 thousand,*** mean LCR and DALY might be reduced by 25%-54%and 16%-40%,respectively,by increasing air exchange rates by 100%,reducing the use of source materials by two-thirds or deploying commercial air cleaners in naturally ventilated ***,avoidable DALYs could result in a reduction of mean economic losses of 2.2-5.3 billion *** ventilation systems with filtration units may not be helpful for reducing children’s health ***-specific and tailor-made control measures are critical in lowering indoor exposure to DEHP to promote sustainable buildings and children’s health in China.

关键词： indoor air di(2-ethylhexyl)phthalate children exposure control strategies health benefits

Impact factors and pathways of halonitromethanes formation from aspartic acid during LED-UV_(265)/chlorine disinfection

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Frontiers of environmental Science & engineering 2024年第1期18卷 129-144页

作者： Liangwen Zhu Tao Wang Qian Tang Qing Wang Lin Deng Jun Hu Chaoqun Tan Rajendra Prasad Singh Key Laboratory of concrete and Prestressed concrete Structures of Ministry of Education School of Civil EngineeringSoutheast UniversityNanjing 211189China college of environment Zhejiang University of TechnologyHangzhou 310014China

Light emitting diode (LED-UV)/chlorine disinfection can replace UV/chlorine disinfection in wastewater treatment plants and water supply plants. Halonitromethanes (HNMs) are a class of novel nitrogenous disinfection by-products, which are characterized by higher cytotoxicity and genotoxicity than regulated disinfection by-products. Herein, the impact factors and pathways of HNMs formation from aspartic acid (ASP) were investigated during LED-UV_(265)/chlorine disinfection. The results showed that three types of chlorinated-HNMs (Cl-HNMs) were found during LED-UV265/chlorine disinfection, and their concentrations increased first and then declined as the reaction progressed. Cl-HNMs yields increased with increasing LED-UV_(265) intensity, free chlorine dosage, and ASP concentration, which declined with increasing pH (6.0–8.0). Meantime, the important impact of the coexisting ions contained in water matrices on HNMs formation from ASP was observed during LED-UV_(265)/chlorine disinfection. It was found that copper ions (Cu^(2+)) promoted Cl-HNMs formation. Furthermore, when bromide (Br–) appeared during LED-UV265/chlorine disinfection, nine types of HNMs were detected simultaneously. Moreover, Br– not only converted Cl-HNMs toward brominated (chlorinated)-HNMs and brominated-HNMs but also showed a marked effect on HNMs concentrations and species. Subsequently, the possible pathways of HNMs formation from ASP were proposed during LED-UV_(265)/chlorine disinfection. At last, it was proved that the formation trends of HNMs obtained in the real waters were similar to those in simulated waters. This work elaborated on the influence factors and pathways of HNMs formation, which is conducive to controlling the HNMs produced during LED-UV_(265)/chlorine disinfection.

关键词： LED-UV265 chlorine HNMs Aspartic acid Bromide copper ions

A Secure Mutual Authentication Protocol Based on Visual Cryptography Technique for IoT-Cloud

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Chinese Journal of Electronics 2024年第1期33卷 43-57页

作者： Brou Bernard Ehui Chen CHEN Shirui WANG Hua GUO Jianwei LIU School of Cyber Sciences and Technology Beihang University State Key Laboratory of Software Development environment Beihang University Sino-French engineering School Beihang University Beihang hangzhou Innovation Institute Yuhang

Because of the increasing number of threats in the IoT cloud, an advanced security mechanism is needed to guard data against hacking or attacks. A user authentication mechanism is also required to authenticate the user accessing the cloud services. The conventional cryptographic algorithms used to provide security mechanisms in cloud networks are often vulnerable to various cyber-attacks and inefficient against new attacks. Therefore,developing new solutions based on different mechanisms from traditional cryptography methods is required to protect data and users’ privacy from attacks. Different from the conventional cryptography method, we suggest a secure mutual authentication protocol based on the visual cryptography technique in this paper. We use visual cryptography to encrypt and decrypt the secret images. The mutual authentication is based on two secret images and *** user requests the ticket from the authentication server(AS) to obtain the permission for accessing the cloud services. Three shared secret keys are used for encrypting and decrypting the authentication process. We analyze the protocol using the Barrows-Abadi-Needham(BAN)-logic method and the results show that the protocol is robust and can protect the user against various attacks. Also, it can provide a secure mutual authentication mechanism.

关键词： Visualization Cloud computing Data privacy Protocols Biometrics (access control) Authentication Resists