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Effect of mineral admixtures and repeated loading on chloride migration through concrete

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第9期11卷 683-690页

作者： wu-man ZHANG Heng-jing BA School of Transportation Science and Engineering Beihang University Beijing 100191 China School of Civil Engineering Harbin Institute of Technology Harbin 150006 China

The effect of fly ash (FA) and ground granulated blast furnace slag (GGBFS) on chloride migration through concrete subjected to repeated loading was examined. Portland cement was replaced by three percentages (20%, 30%, and 40%) of mineral admixtures. Five repeated loadings were applied to concrete specimens using a WHY series fully automatic testing machine. The maximum loadings were 40% and 80% of the axial cylinder compressive strength (f′c). Chloride migration through concretes was evaluated using the rapid chloride migration test and the chloride concentration in the anode chamber was measured. The results showed that the replacement percentages of mineral admixtures, the curing time and repeated loading had a significant effect on chloride migration through concrete. The transport number of chloride through concrete cured for 28 d increased with increasing FA replacement and markedly decreased with extension of the curing time. 20% and 30% GGBFS replacement decreased the transport number of chloride through concrete, but 40% GGBFS replacement increased the transport number. Five repeated loadings at 40% or 80% f′c increased the transport number of chloride for all mixes.

关键词： Concrete Fly ash (FA) Ground granulated blast furnace slag (GGBFS) Chloride migration Repeated loading

Activity origin and design principles for atomic vanadium anchoring on phosphorene monolayer for nitrogen reduction reaction

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Nano Research 2020年第11期13卷 2925-2932页

作者： Xiongyi Liang Xiangxuan Deng Chen Guo Chi-man Lawrence wu Department of Materials Science and Engineering City University of Hong KongHong KongChina

Conversion of inert N2 molecules into NH3 via electrochemical methods is an environmentally friendly alternative to replace the traditional Haber-Bosch ***,the development of highly efficient catalyst is still ***,we report a density functional theory(DFT)based high-throughput screening to investigate the potential of 23 atomic transition metals(Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Y,Zr,Nb,Mo,Tc,Ru,Rh,Pd,Ag,Cd,W,Pt and Au)supported on phosphorene monolayer as electrocatalyst for nitrogen reduction reaction(NRR).Our theoretical results demonstrate that V single atom anchoring on phosphorene monolayer exhibits good thermal stability,selectivity and excellent catalytic activity with a low overpotential of 0.18 ***,rational design principles and electronic descriptor between the intrinsic electronic properties and activation barrier have been *** work offers a new promising noble metal-free catalyst for NRR and reveals profound insights into the activity origin to guide further design.

关键词： high-throughput screening density functional theory phosphorene electronic descriptor single atomic catalyst transition metal

Synergistic Ru/RuO_(2) heterojunctions stabilized by carbon coating as efficient and stable bifunctional electrocatalysts for acidic overall water splitting

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Nano Research 2024年第8期17卷 6931-6939页

作者： man wu Yuying Fan Yang Huang Dongxu Wang Ying Xie Aiping wu Chungui Tian Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080China

The development of highly active and stable acidic water oxidation electrocatalysts is of great significant for promoting the industrial application of proton exchange membrane ***-based catalysts have broad application prospects in acidic water oxidation,but their limitations in stability and activity hinder their further ***,a nitrogen-doped carbon(NC)coated porous Ru/RuO_(2) heterojunctional hollow sphere(Ru/RuO_(2)/NC)is designed as high-active and stable bifunctional electrocatalyst for acidic oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).In synthesis,the key is to use mesoporous polydopamine spheres as a template for forming hollow spheres,a source of NC coating and a reducing agent for forming Ru/RuO_(2) *** Ru/RuO_(2) heterojunction adjusts the electronic structure of Ru active sites,optimizing the adsorption of intermediate ***,the NC coating and the interaction between NC and Ru/RuO_(2) effectively prevent Ru from over-oxidation and *** porous hollow structure provides more exposed active sites and promotes mass ***,Ru/RuO_(2)/NC exhibits outstanding OER and HER performance with low overpotentials of 211 and 32 mV at 10 mA·cm^(−2),respectively,and shows excellent *** acid water splitting electrolyzer,based on the bifunctional Ru/RuO_(2)/NC,requires low cell voltages of 1.46 and 1.76 V at 10 and 100 mA·cm^(−2),respectively,with good stability for over 100 h operation,surpassing Pt/C||RuO_(2) and most of the reported catalysts.

关键词： hollow heterojunction bifunctional electrocatalysts oxygen evolution hydrogen evolution acidic water splitting

Influence of temperature on performance of anaerobic digestion of municipal solid waste

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Journal of Environmental Sciences 2006年第4期18卷 810-815页

作者： ZHANG Ji-shi SUN Ke-wei wu man-chang ZHANG Lei National Engineering Research Center of Solid Waste Resource Recovery Kunming 650033 China Faculty of Environmental Science and Engineering Kunming University of Science and Technology Kunming 650093 China

The influence of temperature on the performance of anaerobic reactors for treating the organic fraction of municipal sohd waste （OFMSW） was studied. Batch digestion of OFMSW was carded out for 32 d at different temperature （25℃, 35℃, 45℃ and 55℃） conditions for total solid concentrations （TS） 17% with the ratio of total organic carbon to nitrogen （C/N） being, 25：1 respectively, while keeping other parameters constant such as inoculum, start-up pH, reactor volume （2 L） and so on. Temperature can influence the methanogenic bacteria activity, accordingly inhibiting the OFMSW biodegradation and stabilization efficiency. Anaerobic reactors excelled at TS reduction, total volatile solid reduction, chemical oxygen demand reduction, increasing cumulative biogas production, whose rate was at temperature （35℃ and 55℃） conditions. Methane concentration in the biogas was above 65% in four reactors. In addition, the fluctuation of temperatures resulted in the biogas production variation. The data obtained indicated that temperature had a significant influence on anaerobic process.

关键词： municipal solid waste anaerobic digestion batch processing temperature

A comparative study on water and dry coupling in photoacoustic tomography of the finger joints

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Journal of Innovative Optical Health Sciences 2020年第4期3卷 1-9页

作者： Qiquan Shang man wu Jinge Yang Ten Pan Guang Zhang Dan wu Huabei Jiang School of Electronic Science and Engineering(National Exemplary School of Microelectronics)University of Electronic Science and Technology of China Chengdu 611731 P.R.China Center for Information in Medicine University of Electronic Science and Technology of China Chengdu 611731 P.R.China Department of Medical Engineering University of South Florida Tampa 33620USA

We present a systematical study on comparison between water and dry coupling in photoacoustic tomography of the humanfinger *** to the direct water immersion of thefinger for water coupling,the dry coupling is realized through a transparent PDMSfilm-based water bag,which ensures water-free contact with the *** results obtained suggest that the dry cou-pling provides image quality comparable to that by water coupling while eliminating the wrin-kling of thefinger joint caused by the water *** addition,the dry coupling offers more stable hemodynamic images than the water coupling as the water immersion of thefinger joint causes reduction in blood vessel size.

关键词： Photoacoustic tomography dry coupling water coupling finger joints

Nitrous oxide research progress in polar and sub-polar oceans

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Advances in Polar Science 2020年第4期31卷 241-247页

作者： ZHAN Liyang ZHANG Jiexia LI Yuhong&wu man Key Laboratory of Global Change and Marine-Atmospheric Chemistry Third Institute of OceanographyMinistry of Natural ResourcesXiamen 361005China

N2O gas depletes ozone and has a powerful greenhouse *** are among the most important N2O sources and have been the subject of extensive *** oceans are important regions for deep water formation and global-scale thermohaline ***,these water bodies play an important role in the N2O budget,however,these regions were not well *** review of previously published studies and data on polar oceans,including both the Arctic Ocean and Southern Ocean,describes the distribution pattern of N2O and possible regulating mechanism of these distribution patterns and shows that the Arctic Ocean and Southern Ocean both represent source and sink regions,suggesting that the source/sink characteristics of the Arctic and Southern oceans and their strengths need further *** related to N2O circulation in polar oceans were proposed,and future work is suggested.

关键词： nitrous oxide source/sink Arctic Ocean Southern Ocean Prydz Bay

Revisiting the Climatology of Atmospheric Blocking in the Northern Hemisphere

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Advances in Atmospheric Sciences 2013年第2期30卷 397-410页

作者： Ho Nam CHEUNG 周文 Hing Yim MOK man Chi wu Yaping SHAO City University of Hong Kong Shenzhen Research Institute Guy Carpenter Asia-Pacific Climate Impact Centre School of Energy and Environment City University of Hong Kong Hong Kong Observatory Institute for Geophysics and Meteorology University of Cologne

In addition to the occurrence of atmospheric blocking, the climatology of the characteristics of blocking events, including duration, intensity, and extension, in four seasons over the Northern Hemisphere was analyzed for the period 1950-2009. The seasonality and spatial variations of these characteristics were studied according to their longitudinal distributions. In general, there were sharp discrepancies in the blocking characteristics between winter and summer, and these differences were more prominent over the Atlantic and Pacific Oceans. The blocking not only occurred more frequently but also underwent stronger amplification in winter; likewise, the blocking occurred less frequently and underwent weaker amplification in summer. There are very strong interrelationships among different blocking characteristics, suggesting that they are supported by similar physical factors. In addition, the relationship between blocking over different regions and East Asian circulation was examined. Ural-Siberia is a major blocking formation region in all seasons that may exert a downstream impact on East Asia. The impact is generally weak in summer, which is due to its lower intensity and smaller duration. However, the extratropical circulation over East Asia in summer can be disturbed persistently by the frequent occurrence of blocking over the Asian continent or the Western Pacific. In particular, the blocking frequency over the Western Pacific significantly increased during the study period. This climatological information provides a background for studying the impact of blocking on East Asian circulation under both present and future climate conditions.

关键词： atmospheric blocking climatology seasonality East Asian circulation

Research on management of Social Public Security in China

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Research on Management of Social Public Security in China

Summer Monsoon Indices on June Rainfall in Hong Kong and Its Vicinity

2007 International Conference on Public Administration（ICPA 3rd）

作者： wu man-yi CHANG Ning School of Political Science and Public Administration University of Electronic Science and Technology of China

With the rapid development of society,problems on social public security become vital and prominent day after day,which calls for much more attention to its *** the discussion on the basic questions about management of social public security (MSPS) and analysis on its definition,features and construction,this article puts forward some technical frames and methods can be carried out in management process

关键词： Society Public security management

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Journal of Meteorological Research 2016年第5期30卷 789-799页

作者： wu man-chi TONG Hang-wai LEE Tsz-cheung Hong Kong Observatory Hong Kong China

Climatologically, June is usually the wettest month in Hong Kong. With significant interannual variation of the summer monsoon, the rainfall variability in June is also large. As Hong Kong is in close proximity to the peripheries of different monsoon regions, the variability of June rainfall largely depends on the relative strength of various monsoon systems. In the present study, a new index comparing the relative condition of the western North Pacific summer monsoon and the South China Sea summer monsoon is developed based on the difference between the respective monsoon indices WNPMI （western North Pacific summer monsoon index） and UMI （unified monsoon index）. It is shown that June rainfall in Hong Kong and its vicinity is better correlated with this new index than either WNPMI or UMI alone. Based on the signs of the new index in conjunction with those of WNPMI and UMI, a framework to stratify the monsoon conditions into different configurations together with a simple scheme to summarize the associated rainfall responses is formulated. This study highlights how the rainfall variability on a local or regional scale can be quantified by the broad-scale conditions of different monsoon systems.

关键词： Hong Kong South China Sea summer monsoon western North Pacific summer monsoon mon- soon index June rainfall bootstrap regional monsoon