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Rainfall erosivity estimation over the Tibetan plateau based on high spatial-temporal resolution rainfall records

International Soil and Water Conservation Research 2022年第3期10卷 422-432页

作者： Yueli Chen xingwu Duan Guo Zhang Minghu Ding Shaojuan lu State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijingChina Institute of International Rivers and Eco-security Yunnan UniversityKunmingChina CMA Earth System Modeling and Prediction Centre BeijingChina

The Tibetan Plateau(TP)in China has been experiencing severe water erosion because of climate *** rapid development of weather station network provides an opportunity to improve our understanding of rainfall erosivity in the *** this study,1-min precipitation data obtained from 1226 weather stations during 2018–2019 were used to estimate rainfall erosivity,and subsequently the spatial-temporal patterns of rainfall erosivity in the TP were *** mean annual erosive rainfall was 295 mm,which accounted for 53%of the annual *** average of 14 erosive events occurred yearly per weather station,with the erosive events in the wet season being more likely to extend beyond *** these cases,the precipitation amounts of the erosive events were found to be higher than those of the daily precipitations,which may result in implicit bias as the daily precipitation data were used for estimating the rainfall *** mean annual rainfall erosivity in the TP was 528 Mj mm·ha^(-1)·h^(-1),with a broader range of 0–3402 Mj mm·ha^(-1)·h^(-1),indicating a significant spatial *** with the highest mean annual rainfall erosivity were located in the forest zones,followed by steppe and desert ***,the precipitation phase records obtained from 140 weather stations showed that snowfall events slightly impacted the accuracy of rainfall erosivity calculation,but attention should be paid to the erosion process of snowmelt in the inner part of the *** results can be used as the reference data for soil erosion prediction in normal precipitation years.

关键词： Erosive rain Rainfall erosivity Spatial-temporal patterns 1-Min precipitation data Tibetan Plateau

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磺胺二甲嘧啶废水处理系统中Exiguobacterium sp.H-1的分离及其环境适应特性

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环境工程技术学报 2024年第1期14卷 258-267页

作者：陈田王壮芦梦瑶陈研周佳屈建航潘婧诗罗宇河南工业大学生物工程学院河南工业大学国际教育学院

磺胺二甲嘧啶(SMZ)是一种难降解的广谱抗生素,其广泛存在已对水环境构成严重的威胁。微生物是环境中抗生素降解转化的主要驱动者,但高效降解SMZ的微生物资源匮乏。以SMZ废水处理系统的活性污泥为原料,采用纯培养技术从中分离筛选出一株... 详细信息

磺胺二甲嘧啶(SMZ)是一种难降解的广谱抗生素,其广泛存在已对水环境构成严重的威胁。微生物是环境中抗生素降解转化的主要驱动者,但高效降解SMZ的微生物资源匮乏。以SMZ废水处理系统的活性污泥为原料,采用纯培养技术从中分离筛选出一株SMZ降解菌H-1。经形态学观察、生理生化特征、16S rRNA基因序列分析,H-1归属于微小杆菌属(Exiguobacterium sp.)。通过单因素试验研究初始SMZ浓度、接种量、pH和温度对菌株H-1降解SMZ效果的影响。结果表明,接种量、pH和温度对该菌株降解SMZ的影响较大。进一步采用响应面法优化菌株Exiguobacterium sp.H-1降解SMZ的最佳条件,得出pH为7.21,温度为28.86℃,接种量为4.40%时,其对5 mg/L SMZ降解率为10.54%。本研究发现微小杆菌Exiguobacterium sp.H-1具有降解SMZ的能力,其降解SMZ的独特之处是能够将SMZ脱去SO_(2),生成嘧啶环和苯胺环,经过耦合生成N-(4,6-二甲基嘧啶-2基)-1,4-二苯胺,然后进行脱氨反应,生成2-苯-4,6-二甲基嘧啶,随后去甲基化生成产物6(2-苯基-1,2-二氢嘧啶,m/z为159.97)。此外,菌株H-1在0~10%NaCl的广泛范围内也表现出很强的耐盐性,能够为SMZ污染水体的生物修复提供耐盐能力强的微生物菌株资源。

关键词：磺胺二甲嘧啶 Exiguobacterium 生物降解环境适应性生物修复

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One-pot synthesis of bimetallic CeCu-SAPO-34 for high-efficiency selective catalytic reduction of nitrogen oxides with NH_(3) at low temperature

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Chinese journal of Chemical Engineering 2023年第4期56卷 193-202页

作者： Shuang Qiu Yonghou xiao Haoran Wu Shengnan lu Qidong Zhao Gaohong He Panjin Institute of Industrial Technology Liaoning Key Laboratory of Chemical Additive Synthesis and SeparationDalian University of TechnologyPanjin 124221China State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyPanjin 124221China School of Petrochemical Engineering Shenyang University of TechnologyLiaoyang 111003China

NH_(3) selective catalytic reduction(SCR) has been widely recognized as a promising technique for reducing nitrogen oxides from diesel vehicle exhausts. High-efficiency SCR catalysts that could perform at low temperatures are essential to denitration. In this work, a series of bimetallic CeCu-SAPO-34 molecular sieves were synthesized by one-step hydrothermal method. The Ce Cu-SAPO-34 maintained good crystallinity and a regular hexahedron appearance of Cu-SAPO-34 after introducing Ce species, while exhibiting a higher specific surface area and pore volume. The as-prepared CeCu-SAPO-34 with 0.02%(mass) Ce constituent exhibited the best catalytic activity below 300℃ and a maximum NO_(x) conversion of 99% was attained;the NO_(x) removal rates of more than 68% and 94% were achieved at 150℃ and 200℃, respectively. And the introduction of cerium species in Cu-SAPO-34 improves the low-temperature hydrothermal stability of the catalyst towards NH_(3)-SCR reaction. Additionally, the introduced Ce species could enhance the formation of abundant weak Br?nsted acid centers and promote the synergistic effect between CuO grains and isolated Cu^(2+) to enhance the redox cycle, which benefit the NH_(3)-SCR *** work provides a facile synthesis method of high-efficiency SCR denitration catalysts towards diesel vehicles exhaust treatment under low temperature.

关键词： CeCu-SAPO-34 Selective catalytic reduction(SCR) Low temperature DeNO_(x) One-pot synthesis

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THE STRAIN CYCLIC CHARACTERISTICS AND RATCHETING OF U71Mn RAIL STEEL UNDER UNIAxIAL LOADING

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Acta Metallurgica Sinica(English Letters) 2000年第3期13卷 893-900页

作者： G.Z. Kang Q. Gao, x.j.Yang and Y.F. Sun(Department of Applied Mechanics and Engineering, Southwest jiaotong University, Chengdu 610031, China) Southwest jiaotong Univ Chengdu China

An experimental study was carried out of the cyclic behavior of U71Mn rail steel subjected to uniaxial strain and stress. The effects of cyclic struin amplitude, mean struin,strain loading rate and their histories on the strain cyclic characteristics were *** the asymmetrical stress cycling, the effects of stress amplitude, mean stress,stress loading rate and their histories on the ratcheting were analyzed. The interaction between strain cycling and stress cycling was also discussed. It is shown that either the cyclic characteristics under strain cycling or the ratcheting under asymmetrical stress cycling depends not only on the cumnt loading state, but also on the previous loading history. Some significant results are obtained.

关键词： cyclic plasticity ratcheting U71Mn rail steel uniaxial loading

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Mitigating parametric instabilities in plasmas by sunlight-like lasers

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Matter and Radiation at Extremes 2021年第5期6卷 54-61页

作者： H.H.Ma x.F.Li S.M.Weng S.H.Yew S.Kawata P.Gibbon Z.M.Sheng j.Zhang Key Laboratory for Laser Plasmas(MoE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghai 200240China Graduate School of Engineering Utsunomiya UniversityYohtoh 7-1-2Utsunomiya 321-8585Japan Institute for Advanced Simulation J¨ulich Supercomputing CentreForschungszentrum J¨ulich52425 J¨ulichGermany Centre for Mathematical Plasma Astrophysics Katholieke Universiteit Leuven3000 LeuvenBelgium SUPA Department of PhysicsUniversity of StrathclydeGlasgow G40NGUnited Kingdom Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

Sunlight-like lasers that have a continuous broad frequency spectrum,random phase spectrum,and random polarization are formulated *** a sunlight-like laser beam consisting of a sequence of temporal speckles,the resonant three-wave coupling that underlies parametric instabilities in laser–plasma interactions can be greatly degraded owing to the limited duration of each speckle and the frequency shift between two adjacent *** wave coupling can be further weakened by the random polarization of such *** simulations demonstrate that the intensity threshold of stimulated Raman scattering in homogeneous plasmas can be doubled by using a sunlight-like laser beam with a relative bandwidth of∼1%as compared with a monochromatic laser ***,the hot-electron generation harmful to inertial confinement fusion can be effectively controlled by using sunlight-like laser *** drivers may be realized in the next generation of broadband lasers by combining two or more broadband beams with independent phase spectra or by applying polarization smoothing to a single broadband beam.

关键词： polarization scattering speckle

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Saturated coordinated control of multiple underactuated unmanned surface vehicles over a closed curve

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Science China(Information Sciences) 2017年第7期60卷 40-53页

作者： lu LIU Dan WANG Zhouhua PENG Hugh H.T.LIU School of Marine Engineering Dalian Maritime University Department of Computer Science City University of Hong Kong Institute for Aerospace Studies University of Toronto

This paper presents a design method for saturated coordinated control of multiple underactuated unmanned surface vehicles(USVs) on a closed curve, holding a symmetric formation pattern. Each vehicle is subject to unknown sideslip, uncertain vehicle kinetics, and limited control torques. First, the course angle and surge velocity are considered as immediate signals to stabilize the along-track and cross-track path following errors. In the vehicle kinematics, a reduced-order extended state observer is utilized to compensate for the effect of the unknown sideslip. Next, a bounded neural network control law is constructed at the kinetic level with the aid of the a saturated function, a projection operator, and a dynamic surface design method. Finally, a parameter cyclic pursuit approach is presented to guarantee that the vehicles are evenly spaced over the closed curve for achieving a symmetric formation pattern. The input-to-state stability of the closed-loop system is analyzed via cascade theory. Comparative studies are given to show the effectiveness of the proposed method.

关键词： symmetric formation pattern parameter cyclic pursuit reduced-order extended state observer neural networks saturated control

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On the texture evolution of Mg-Zn-Ca alloy with different hot rolling paths

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journal of Magnesium and Alloys 2017年第2期5卷 166-172页

作者： Q.Li G.j.Huang x.D.Huang S.W.Pan C.L.Tan Q.Liu College of Materials Science and Engineering Chongqing UniversityChongqing 400044China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

In the present study,the texture evolution and mechanical anisotropy in a typical Mg–Zn–Ca alloy through hot cross rolling(CR)and unidirectional rolling(UR)were systematically *** results show that the rolling path greatly affects the annealed *** UR develops a texture with basal poles mainly distributing along the transverse direction(TD).By contrast,an ellipse-like(0002)texture with basal pole inclining largely away from the normal direction(ND)is developed after hot cross rolling and ***,the CR is an effective method to tailor the texture of the experimental ***,this ellipse-like texture could not reserve during the subsequent unidirectional hot rolling and *** UR and CR plates exhibit a strong planar mechanical anisotropy compared with the traditional unidirectional rolled plate.

关键词： Mg alloys Hot cross rolling Texture Mechanical anisotropy

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The study on county accessibility in China： Characteristics and effects on population agglomeration

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journal of Geographical Sciences 2011年第1期21卷 18-34页

作者： WANG Zhenbo xU jiangang FANG Chuanglin xU lu QI Yi Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China

This paper calculated spatial accessibility of all counties （city,urban district） in China with cost weighted distance method. Region divisions of county accessibility were conducted,and relation of traffic accessibility and population aggregation was discussed in this paper. The results indicated that county accessibility in China had mainly low values and a distribution structure of circle layer and reverse-to-natural gradient. There was an obvious correlation between county accessibility and population density in China. With these analyses,inner mechanisms of population migration in different traffic conditions and region types were revealed,and can provide useful proposals to regional planning,traffic planning and smart distribution of people in China.

关键词： county spatial accessibility population aggregation raster cost weighted China

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Efficacy of water fraction from Dioscorea cirrhosa on oxidative stress and apoptosis in H9c2 cardiomyocytes induced by H2O2

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journal of Traditional Chinese Medicine 2021年第1期41卷 51-58页

作者： LIU Chunhua PAN jie WANG Aimin LAN Yanyu LI Yongjun lu Yuan SUN jia WANG Yonglin LIU Ting lu Dingyan YOU jingrui State Key Laboratory of Functions and Applications of Medicinal Plants Engineering Research Center for the Development and Application of Ethnic Medicine and Traditional Chinese Medicine(Ministry of Education)Guizhou Medical UniversityGuiyang 550004China Guizhou Provincial Key Laboratory of Pharmaceutics Guizhou Medical UniversityGuiyang 550004China School of Pharmacy Guizhou Medical UniversityGuiyang 550004China

OBjECTIVE:To investigate the efficacy of water fraction from Dioscorea cirrhosa(WF)on oxidative damage and apoptosis of cardiomyocytes induced by H2O2,and to study its ***:Cell viability was measured by the MST assay *** content of malondialdehyde(MDA),release of lactate dehydrogenase(LDH)and activity of catalase(CAT)and superoxide dismutase(SOD)were detected by biochemical *** content of reactive oxygen species(ROS)was assessed by nonfluorescent probe 2′,7′-dichlorofluorescin diacetate(DCFH-DA).jC-1 was used to analyze the mitochondrial membrane potential(mtΔΨ)and Annexin-V-FITC/PI staining was applied to assess apoptosis of H9c2 by flow ***,the expression of B-cell lymphoma-2(Bcl-2),Bcl-2-associated x(Bax),caspase-3,caspase-9,cleaved-caspase-3 and cleaved-caspase-9 proteins was determined by western blot ***:WF increased cell viability and decreased LDH leakage in H9c2 cells exposed to *** treatment decreased ROS and MDA level,enhanced SOD and CAT activities,improved mtΔΨand inhibited *** blot analysis demonstrated that the ratio of Bcl-2/Bax was increased and the expression cleaved-caspase-3,caspase-3,cleaved-caspase-9 and caspase-9 were decreased in group treated with ***:WF protects H9c2 myocardial cells on H2O2-induced oxidative stress and apoptosis by scavenging ROS,improving antioxidant capacity,protecting mitochondrial and regulating the proteins expression related to apoptosis.

关键词： Dioscorea water fraction hydrogen peroxide oxidative stress apoptosis myocytes,cardiac

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Cathodic reaction mechanisms in CO2 corrosion of low-Cr steels

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International journal of Minerals,Metallurgy and Materials 2019年第11期26卷 1405-1414页

作者： jin-yang Zhu Li-ning xu Min-xu lu Wei Chang National Center for Materials Service Safety University of Science and Technology BeijingBeijing 100083China Corrosion and Protection Center Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China CNOOC Research Institute Beijing 100027China

The cathodic reaction mechanisms in CO2 corrosion of low-Cr steels were investigated by potentiodynamic polarization and galvanostatic *** but different dominant cathodic reactions were observed at different p H *** the higher p H level(p H>~5),H2 CO3 reduction was the dominant cathodic *** reaction was under activation *** the lower pH level(pH<~3.5),H+reduction became the dominant one and the reaction was under diffusion *** the intermediate area,there was a transition region leading from one cathodic reaction to *** measured electrochemical impedance spectrum corresponded to the proposed cathodic reaction mechanisms.

关键词： low alloy steel carbon dioxide corrosion EIS cathodic reaction mechanisms

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