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Exploring the impact of Nafion modifier on electrocatalytic CO_(2) reduction over Cu catalyst

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Journal of Energy Chemistry 2024年第1期88卷 543-551,I0012页

作者： Yingshi su Yonghui Cheng Zhen li Yanjia Cui Caili yang Ziyi Zhong Yibing Song Gongwei Wang lin Zhuang College of Chemistry&Chemical Engineering and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou 515063GuangdongChina College of Chemistry and Molecular Sciences Hubei Key Lab of Electrochemical Power SourcesWuhan UniversityWuhan 430072HubeiChina The Institute for Advanced Studies Wuhan UniversityWuhan 430072HubeiChina Department of Chemistry Engineering Guangdong Technion-Israel Institute of Technology(GTIIT)Shantou 515063GuangdongChina Technion-Israel Institute of Technology(IIT) Haifa 32000Israel

Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Herein,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)electrocatalyst.We found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product generation.Owing to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction.Thus,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.

关键词： Nafion modifier CO_(2)reduction Cu nanoparticles In situ ATR-SEIRAS C_(2)product

A review of linear friction welding of Ni -based superalloys

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1382-1391页

作者： Xiawei yang Tingxi Meng Qiang Chu Yu su Zhenguo Guo Rui Xu Wenlong Fan Tiejun Ma Wenya li State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding TechnologiesNorthwestern Polytechnical UniversityXi’an 710072China Xi’an Aerospace Engine Co.Ltd. Xi’an 710100China

Ni-based superalloys are one of the most important materials employed in high-temperature applications within the aerospace and nuclear energy industries and in gas turbines due to their excellent corrosion,radiation,fatigue resistance,and high-temperature strength.linear friction welding(LFW)is a new joining technology with near-net-forming characteristics that can be used for the manu-facture and repair of a wide range of aerospace components.This paper reviews published works on LFW of Ni-based superalloys with the aim of understanding the characteristics of frictional heat generation and extrusion deformation,microstructures,mechanical proper-ties,flash morphology,residual stresses,creep,and fatigue of Ni-based superalloy weldments produced with LFW to enable future optim-um utilization of the LFW process.

关键词： Ni-based superalloys linear friction welding microstructures mechanical properties flash morphology

Composite Converter Combined APFC with Switched-capacitor Converter

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 281-291页

作者： Qing Fu Yishan Chen Yixing su yang Hang School of Physics Sun Yat-Sen UniversityGuangzhou 510275China

To reduce switch numbers and voltage stress in semiconductor devices,this paper proposes a novel single-phase converter combined Active Power Factor Correction(APFC)with switched-capacitor converter.In addition,dynamic voltage regulation and voltage gain are improved by integrating the boost converter and switching capacitor cells.The interstage bulk capacitor is no longer needed.An average current control with redistribution of voltage in cells is proposed to obtain voltage lift ability of the switching capacitor cells and maintain a high-power factor.To study and verify the proposed converter preliminarily,theoretical analysis and simulation are presented in the paper.Furthermore,a 50o W prototype with two different configurations is built for experimental verification.The proposed converter can reach 95.62%of maximum efficiency,0.99 of power factor,and 3.55%of THD with 600 V output voltage,simultaneously.

关键词： AC-DC converter composite conveter power factor correction switched capacitor

Temporal and Spatial Trends in HIV Positivity Rate for VCT Clinics—China,2015–2022

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China CDC weekly 2024年第1期6卷 6-11页

作者： Yi liu Rong su Dongmin li Shaorong Wang Mengjie Han National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina

Introduction:Human immunodeficiency virus(HIV)voluntary counseling and testing(VCT)clinics play a critical role in identifying and diagnosing HIV cases.This study aimed to describe the trend of HIV positivity rate(HPR)among Chinese VCT clinics between 2015 and 2022.Methods:This study utilized data from the China Information System for Disease Control and Prevention to analyze the trend in the HPR for VCT clinics from 2015 to 2022.The HPR was calculated by dividing the number of newly-reported HIV cases by the number of HIV tests,multiplied by 100%.To identify temporal and spatial trends in the HPR,we employed joinpoint regression analysis and the Getis-Ord hotspot analysis.Results:From 2015 to 2022,VCT clinics in China performed a total of 22,075,386 HIV tests,leading to the identification of 260,353 HIV cases,resulting in a HPR of 1.18%.The HPR consistently declined over the study period,with an average annual percent change(AAPC)of−7.5%(95%confidence interval:−12.6%,−2.2%,Plinics in China have played a significant role in identifying HIV cases.The declining HPR observed in these clinics may indicates the progress has been made in some degree in mitigating HIV among high-risk populations.Therefore,it is crucial to further improving the utilization of VCT clinics for HIV testing.

关键词： VCT dividing Spatial

Putrescine Modulates Cadmium Fixation Ability of Cell Wall to Decrease Cadmium Accumulation in Rice,a Process Might Depend on Nitric Oxide

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Rice science 2024年第3期31卷 237-240,I0002-I0007页

作者： WANG Haoyu li su yang Jibo HUANG Jing ZHU Xiaofang SHEN Renfang ZENG Dali College of Advanced Agricultural Sciences Zhejiang A&F UniversityHangzhou 311300China State Key Laboratory of Soil and sustainable Agriculture Institute of Soil ScienceChinese Academy of ScienceNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China

Although putrescine(PUT)has been linked to plants'responses to cadmium(Cd)stress,the exact mechanism is still elusive.In the current investigation,the endogenous PUT concentration in rice roots was enhanced by Cd stress.Exogenous PUT increased root cell wall hemicellulose levels,which in turn increased its Cd binding capacity,concurrently decreasing the transcription level of genes such as OsNRAMP1 and OsCd1 that are responsible for root Cd absorption.As a result。

关键词： absorption roots cadmium

Heterogeneous integration of 2D materials on Si charge-coupled devices as optical memory

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Science China(Information Sciences) 2024年第6期67卷 190-197页

作者： Zheng BIAN Feng TIAN Zongwen li Xiangwei su Tianjiao ZHANG Jialei MIAO Bin YU yang XU Yuda ZHAO College of Integrated Circuits Hangzhou Global Scientific and Technological Innovation CentreZhejiang University

Optical memory integrates the function of optical sensing in memory devices, remarkably promoting the interconnection between sensory and memory terminals. Silicon charge-coupled photodetectors and floating gate memory have been widely used in imaging and storage technologies, respectively. However,the heterogeneous integration of the two devices requires technological innovation and complex electrical connections. In this work, we adopt a three-dimensional layer stacking method to design a novel optical memory device. On the top of Si charge-coupled photodetectors, we successively deposit two-dimensional graphene,hexagonal boron nitride, and molybdenum disulfide as a floating gate layer, a tunneling layer, and a readout layer, respectively. By applying a gate bias on lightly doped Si, a deep depletion layer is formed with a high voltage potential drop. Under dark conditions, the depletion layer cannot be filled, and the electric field across the h-BN tunnel barrier is relatively small. Under light irradiation, the deep depletion layer is gradually filled, and the h-BN tunneling layer withstands the increasing electric field, resulting in charge storage in the floating gate layer. Based on this mechanism, the device exhibits a gate voltage-dependent operation mode, including an integrated optical sensing-memory mode and an electrically driven storage mode. Under moderate gate voltage, the device can effectively detect the optical information with varied intensity and store the optical information in the floating gate, displaying optically controlled memory characteristics. Our work demonstrates a compact device structure for optical memory and displays excellent optically controlled memory performance, which can be applied in artificial vision systems.

关键词： heterogeneous integration charge-coupled device floating gate optical memory molybdenum disulfide lightly doped silicon

A MOF/poly(thioctic acid)composite for enhanced gold extraction from water matrices

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Nano Research 2024年第1期17卷 382-389页

作者： Ruiqing li Sen Yan Tianwei Xue Rongxing Qiu Yin li Wenli Hao Guangkuo Xu Yanliang Wang Yanzhen Hong Yuzhong su Hongtao Wang Shuliang yang li Peng Jun li College of Chemistry and Chemical Engineering Xiamen UniversityXiamen 361005China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China College of Energy Xiamen UniversityXiamen 361005China National Engineering Laboratory for Green Chemical Productions of Alcohols Ethers and EstersXiamen UniversityXiamen 361005China Collaborative Innovation Center of Chemistry for Energy Materials Xiamen UniversityXiamen 361005China

With the fast generation of electronic waste(e-waste)and the increasing depletion of metal resources,“urban mining”that can selectively recover gold from secondary resources has attracted great interest.Construction of materials with high extraction capacity and satisfying selectivity in complex aqueous-based matrices still remains challenging.Here,a novel metal-organic framework/polymer composite(Fe-BTC/poly(thioctic acid),denoted as Fe-BTC/pTA)has been newly synthesized and applied for selective gold recovery in different matrices(river water,seawater,and leaching solution of e-waste).Benefiting from the high specific surface area and suitable pore sizes as well as the rational design of active sites,the composite exhibits high adsorption capacity(920 mg/g),high removal efficiency(>99%),fast kinetics(below 0.1 ppb within 10 min),and good applicability in complex matrices,which are better than those of most reported sulfur-containing adsorbents.Solid-state metallic gold with high purity can be effectively enriched due to the high recyclability and long-term stability of the composite.The material after adsorption can be further applied as a heterogeneous catalyst for water remediation due to the in situ generated gold nanoparticles by the redox reaction between Au(III)ions and the S-containing groups in the composites.

关键词： metal-organic frameworks(MOFs) poly(thioctic acid)(pTA) polymer composites gold recovery urban mining

Numerical simulation of microwave-induced cracking and melting of granite based on mineral microscopic models

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1512-1524页

作者： Xiaoli su Diyuan li Junjie Zhao Mimi Wang Xing su Aohui Zhou School of Resources and Safety Engineering Central South UniversityChangsha 410083China

This study introduces a coupled electromagnetic–thermal–mechanical model to reveal the mechanisms of microcracking and mineral melting of polymineralic rocks under microwave radiation.Experimental tests validate the rationality of the proposed model.Embedding microscopic mineral sections into the granite model for simulation shows that uneven temperature gradients create distinct molten,porous,and nonmolten zones on the fracture surface.Moreover,the varying thermal expansion coefficients and Young's moduli among the minerals induce significant thermal stress at the mineral boundaries.Quartz and biotite with higher thermal expansion coefficients are subjected to compression,whereas plagioclase with smaller coefficients experiences tensile stress.In the molten zone,quartz undergoes transgranular cracking due to theα–βphase transition.The local high temperatures also induce melting phase transitions in biotite and feldspar.This numerical study provides new insights into the distribution of thermal stress and mineral phase changes in rocks under microwave irradiation.

关键词： microwave numerical modeling microcracking phase change granite

Stochastic and Distributed Optimal Energy Management of Active Distribution Networks Within Integrated Office Buildings

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 504-517页

作者： Zening li su su Xiaolong Jin Mingchao Xia Qifang Chen Koji Yamashita National Active Distribution Network Technology Research Center Beijing Jiaotong UniversityBeijing 100044China Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin 300072China Electrical and Computer Engineering University of California RiversideCA92521USA.

This paper proposes a stochastic and distributed optimal energy management approach for active distribution networks(ADNs)within office buildings.The proposed approach aims at scheduling office buildings fitted with heating ventilation and air conditioning(HVAC)systems,and electric vehicle(EV)charging piles,to participate in the ADN optimization.First,an energy management approach for the ADN with aggregated office buildings is proposed.And the ADN optimization model is formulated considering the detailed building thermal dynamics and the mobile behaviors of workers.Then,to consider un-certainties of photovoltaic(PV)power,scenario-based stochastic programming is integrated into the ADN optimization model.To further realize the stochastic energy management of the ADN within office buildings in a distributed manner,the alternating direction method of multipliers(ADMM)is used to solve the ADN optimization model.The original ADN optimization problem is divided into the network-side and the building-side sub-problems to effectively protect the privacy of the ADN and the office buildings.Finally,the ADN optimization model incorporating office buildings is validated in the winter by numerical studies.In addition,the impacts of comfort temperature range and expected state of charge(SOC)at departure are analyzed.Index Terms—ADN,EV,HVAC system,Office building,Stochastic and distributed energy management.

关键词： ADN EV HVAC system Office building Stochastic and distributed energy management