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Amorphous electrocatalysts for urea oxidation reaction

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Progress in Natural science:Materials International 2024年第2期34卷 362-375页

作者： Fenghui Guo Dongle cheng Qian chen Hao Liu Zhiliang Wu Ning Han Bing-Jie Ni Zhijie chen School of Materials science and Technology China University of Geosciences Shenzhen Academy of Metrology and Quality Inspection Centre for Technology in Water and Wastewater School of Civil and Environmental Engineering University of Technology Sydney College of Safety and environmental Engineering Shandong University of Science and Technology Institute of Yellow River Delta Earth Surface Processes and Ecological Integrity Shandong University of Science and Technology Discipline of Chemical Engineering Western Australian School of Mines: Minerals Energy and Chemical Engineering Curtin University department of Materials Engineering School of Civil and environmental Engineering The University of New South Wales

Electrochemical urea oxidation reaction(UOR) is a promising alternative to oxygen evolution reaction(OER) for realizing energy-saving hydrogen production. Developing efficient electrocatalysts for UOR becomes a central challenge. Recently, amorphous materials have been extensively used as UOR catalysts because of their numerous defective sites and flexible electronic properties. In this review, recent advancements in the development of amorphous UOR electrocatalysts are analyzed. The UOR mechanism is discussed, and the design of amorphous catalysts is then analyzed. The main catalyst design strategies are illustrated, including nanostructure control,heteroatom doping, composition regulation, and heterostructure construction. Also, electrocatalysts' structureperformance correlation is interpreted. Perspectives in this field are proposed for guiding future studies on the development of high-performance amorphous catalysts towards energy sustainability.

关键词： Catalyst design Hydrogen energy Heterostructures Heteroatom doping Component regulation

Geomorphic Characteristics of Hillslope and Channelized Debris Flows: A Case Study in the Shitou Area of Central Taiwan

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Journal of Mountain science 2009年第3期6卷 266-273页

作者： Jinn-Chyi chen Ching-Weei LIN Lung-Chang WANG department of environmental and Hazards-Resistant Design Huafan University department of Earth sciences National Cheng Kung University

The data on the hillslope and channelized debris flows in the Shitou area of central Taiwan occurred during Typhoons Toraji and Nali in 2.01 were applied in this paper. The geomorphic parameters, including the flow length, gully gradient, drainage area and form factor of the debris flows were determined by spatial analysis using a Geographic Information System (GIS) based on the data derived from field investigation, aerial photographs, and topographical maps. According to such determined geomorphic parameters, the threshold conditions and empirical equations, such as the relationship between the gully gradient and drainage area and that between gully length and drainage area and topographic parameter, are presented and used to distinguish the geomorphic characteristics between the channelized and hillslope debris flows.

关键词： Hillslope debris flow Channelized debris flow Empirical equation Topographic parameter Central Taiwan china

Modified accumulation of selected heavy metals in Bt transgenic rice

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Journal of environmental sciences 2009年第11期21卷 1607-1612页

作者： WANG Haiyan, huang Jianzhong, YE Qingfu, WU Dianxing, chen Ziyuan Institute of Nuclear Agricultural {2.s, Key Laboratory of Nuclear Agricultural {2.s of Ministry of Agriculture and Zhejiang Province, Zhejiang university, hangzhou 31002., china [a]Institute of Nuclear Agricultural sciences Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province Zhejiang University Hangzhou 310029 China

Safety assessment of genetically modified crops generally does not take into account the potential hazard of altered patterns of heavy metal accumulation in plants. A pot experiment was conducted under greenhouse conditions to evaluate the impact of heavy metal amendments on the accumulation of Cd, Cu, Pb and Zn in a Bt transgenic rice Ke-Ming-Dao （KMD） and its wild-type Xiushui 11 （Xs11）. In control soils, significant difference was only found in contents of Cu （p 〈 0.01） and Pb （p 〈 0.05） in straw between KMD and Xs11. At three levels of Cd amendments （5, 10, and 2. mg/kg）, the Cd contents in grain and straw of KMD were significantly higher than those of Xs11, and all grain Cd contents were significantly higher than the International Criteria （0.2.0.4 mg/kg） as specified by the Codex Alimentarius Commission （CAC）. These results implied that it may be unsafe for growing Bt transgenic rice in heavily Cd-polluted areas. No significant difference in Zn was found between the two varieties with the exception of roots at Zn amendment level of 600 mg/kg, while Pb contents in KMD were much higher in the straw at the lead amendment level of 1000 mg/kg and in the root at 2.0 mg Pb/kg. Data on the heavy metal accumulation patterns for the genetically modified rice may be used for the selection of growing areas as well as for plant residue management for Bt rice.

关键词： Bt transgenic rice heavy metal bioaccumulation trace elements

Risk Assessment of Nitrogen Discharge from a Coastal Watershed

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Pedosphere 2007年第4期17卷 467-474页

作者： chen Neng-Wang HONG Hua-Sheng ZHANG Luo-Ping CAO Wen-Zhi State Key Laboratory of Marine environmental science Environmental Science Research Center Xiamen University Xiamen 361005 （China）.

Probabilistic risk assessment （PRA） uses probability theory to quantify the probability of occurrence of an event. In this study, PRA was conducted for the discharge of excess nitrogen （N） from an agricultural （Jiulong River） watershed in Southeast china. Using fault tree analysis, a type of PRA, the probability of occurrence of excess N discharge into the river during a runoff event was evaluated both qualitatively and quantitatively. Land use maps, soil maps, fertilizer use records, and expert opinions were used to determine probabilities of individual events within the fault tree and to calculate the overall probability of excess N discharge during a runoff event. Qualitative analysis showed that the risk of excess N discharge was mainly related to crop and livestock practices in the watershed. Proper management of tillage, fertilizer, and manure was necessary to control N releases. Quantitative assessment results indicated that alternative practices including reduction of fertilization, installation of vegetative strip buffer around the pig farms, and installation of more riparian buffers along the Jiulong River could reduce the likelihood of N discharge through runoff.

关键词： N discharge probabilistic risk assessment runoff watershed

Cobalt-loaded carbon nanotubes boosted aerobic ciprofloxacin transformation driven by sulfide:A comprehensive mechanism investigation

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Chinese Chemical Letters 2024年第3期35卷 127-134页

作者： Han-Qing Zhao Peili Lu Fei chen chen-Xuan Li Rui Yan Yang Mu State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China CAS Key Laboratory of Urban Pollutant Conversion Department of Environmental Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment College of Environment and EcologyChongqing UniversityChongqing 400045China College of Resources and environmental Engineering Hefei University of TechnologyHefei 230009China

Sulfide oxidation under aerobic conditions can produce active oxygen for the transformation of organic pollutants in aquatic ***,the catalytic performance of transition metal-supported carbon material on this process is poor *** study found that Co-loaded carbon nanotubes(CNTs)was able to realize the efficient aerobic transformation of antibiotic ciprofloxacin(CIP)by sulfide,with the pseudo-first order reaction rate constant improved from 0.013 h^(-1)without catalyst to 0.44–0.71 h^(-1)with 100 mg/L Co-loaded *** oxygen(^(1)O_(2.)was the main active specie playing key roles in the process of CIP aerobic transformation with presence of Co-loaded *** studies indicated that the excellent electron transfer ability of Co-loaded CNTs might play an important role to promote the electron transfer and facilitate the formation of intermediate H_(2.O_(2.and^(1)O_(2..Additionally,the Co-loaded CNTs/sulfide system effectively reduced the acute toxicity of organic pollutant,and Co-loaded CNTs showed remarkable cycling stability and negligible *** study gives a better understanding for the Co-loaded CNTs mediated aerobic antibiotics transformation by sulfide,and provide a reference for the application of Co-loaded carbon materials on organics aerobic transformation by sulfide.

关键词： Ciprofloxacin Aerobic transformation Co-loaded carbon nanotubes Sulfide Singlet oxygen

EXPERIMENTAL STUDY OF FRICTION FACTOR FOR GROUNDWATER FLOW IN A SINGLE ROUGH FRACTURE

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Journal of Hydrodynamics 2009年第6期21卷 820-825页

作者： chen Zhou QIAN Jia-zhong LUO Shao-he ZHAN Hong-bin School of Resources and environmental Engineering Hefei University of Technology Hefei 230009 China department of Resources and Environment Henan Polytechnic University Jiaozuo 454010 China department of Geology and Geophysics Texas A and M University College Station TX 77843-3115 USA

To study the relationships between the friction factor f and the flow type in a single rough fracture, the formulae of f for both unconfined and confined flows are deduced based on previous studies. The relationships between f and the Reynolds number （Re） for different relative roughnesses are investigated experimentally. The Moody-type diagram, based on the deduced formula of f, is also plotted and the hydraulic characteristics of the flow in a rough fracture are analyzed. Results show that the Moody-type diagram of the experiment has a similar distribution to that of the conventional Moody diagram. It is found that the value of f in the experiment is much smaller than that of the conventional Moody diagram and turbulent flow appears easier for rough fractures, which can be explained by the separation phenomenon in boundary layers. The critical Re ranging from 650 to 700 in rough fractures is concluded based on the experimental results. It also can be concluded that the friction factor f is related not only with the Re and the relative roughness but also with the absolute roughness.

关键词： friction factor rough fracture Moody diagram critical Reynolds number ( Re ) boundary layer

A super sandstorm altered the abundance and composition of airborne bacteria in Beijing

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Journal of environmental sciences 2024年第10期144卷 35-44页

作者： Fanxuan Xia Zhuo chen Enze Tian Jinhan Mo Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Department of Building ScienceTsinghua UniversityBeijing 100084China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China College of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China Key Laboratory of Coastal Urban Resilient Infrastructures(Shenzhen university) Ministry of EducationShenzhen 518060China Key Laboratory of Eco Planning&Green Building(Tsinghua university) Ministry of EducationBeijing 100084China

Sandstorm,which injects generous newly emerging microbes into the atmosphere covering cities,adversely affects the air quality in built ***,few studies have examined the change of airborne bacteria during severe sandstorm *** this work,we analyzed the airborne bacteria during one of the strongest sandstorms in East Asia onMarch 15th,2.2.,which affected large areas of china and *** characteristics of the sandstorm were compared with those of the subsequent clean and haze *** composition of the bacterial community of air samples was investigated using quantitative polymerase chain reaction(qPCR)and high-throughput sequencing *** the sandstorm,the particulate matter(PM)concentration and bacterial richnesswere extremely high(PM2.5:2.7μg/m3;PM10:1630μg/m3;5700 amplicon sequence variants/m3).In addition,the sandstorm brought 10 pathogenic bacterial genera to the atmosphere,posing a grave hazard to human *** the sandstorm subsided,small bioaerosols(0.65–1.1μm)with a similar bacterial community remained suspended in the atmosphere,bringing possible long-lasting health risks.

关键词： Airborne bacteria Sandstorm Bioaerosol Haze Pathogen

Break of thermal equilibrium between optical and acoustic phonon branches of CsPbI_(3)under continuous-wave light excitation and cryogenic temperature

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Chinese Chemical Letters 2024年第7期35卷 534-537页

作者： Rongliang Deng Yihang chen Xiaotong Fan Guolong chen Shuli Wang Changzhi Yu Xiao Yang Tingzhu Wu Zhong chen Yue Lin department of Electronic science Fujian Engineering Research Center for Solid-State LightingXiamen UniversityXiamen 361005China Innovation Laboratory for sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361102China Institute of Electromagnetics and Acoustics School of Electronic Science and EngineeringXiamen UniversityXiamen 361005China

The kinetic of low-temperature carrier and lattice of lead-halide perovskite is yet to be fully *** this work,we investigate the steady-state photoluminescences(PLs)of CsPbI_(3)at the environmental temperature(Te)ranging from 2. K to 300 K,and observed anomalous behaviors at cryogenic temperatures:The carrier temperature(Tc)of pure CsPbI_(3)exhibits a negative correlation with Te,accompanied by an expansion in Urbach tails of absorption spectra(Abs.)and excessive red-shifts at peak energy of *** phenomena are also observed in those samples containing a certain amount of Cs_(4)PbI_(6),but to a lesser extent and occurs at lower *** is attributed to the intensified hot phonon bottleneck effect(HPB)in CsPbI_(3)at cryogenic Te,which hinders the energy transfer from hot carriers,via longitudinal optics(LO)phonons to longitudinal acoustic(LA)phonons,to the *** samples under continuous-wave laser excitation,in specific,the barrier induced by the enhanced HPB at low Teprevents the effective thermalization among carriers,LO and LA phonons,which,therefore,form thermally isolated ensembles with different *** cryogenic Terange,the elevated temperatures of carrier and LO phonon expand the high-energy side of PLs and the low-energy tail of Abs.,*** those samples in which the CsPbI_(3)is mixed with Cs_(4)PbI_(6),the interfacial LO-LO interaction across them provides a bypass for heat dissipation,mitigating the heat accumulation in LO-phonons of CsPbI_(3).The results suggest that a strong HPB effect may break the thermal equilibrium among different branches of phonons in the lattice under certain extreme conditions.

关键词： CsPbI_(3) Cs_(4)PbI_(6) Low-temperature carrier Lattice kinetic Hot phonon bottleneck effect Interfacial LO-LO interaction

Discrete large eddy simulation

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Communications in Nonlinear science and Numerical Simulation 2001年第1期6卷 17-22页

作者： L. TAO, K. R. RAJAGOPAL and G. Q. chen(department of Mechanical Engineering, Texas A&M {2., College Station, Texas 77843-312.,USACentre for environmental sciences, Peking {2., Beijing 100871, china ) department of Mechanical Engineering Texas A and M University College Station TX 77843-3123 United States Centre for environmental sciences Peking University Beijing 100871 China

Despite the intense effort expended towards obtaining a model for describing the turbulent flows of fluid, there is no model at hand that can do an adequate job. This leads us to look for a non-traditional approach to turbulence modeling. In this work we conjoin the notion of large eddy simulation with those of fuzzy sets and neural networks to describe a class of turbulent flows. In previous works we had discussed several issues concerning large eddy simulation such as filtering and averaging. Here, we discuss the use of fuzzy sets to improve the filtering procedure.

关键词： large eddy simulation fuzzy set neural network turbulence modeling