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Numerical Simulation of Rainfall-induced Xianchi Reservoir Landslide in Yunyang,Chongqing,China

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 505-517页

作者： yan Jinkai ma.yan LIU Lei WANG Zhihui REN Tianxiang Chinese Academy of Geological Sciences Beijing 100037China Urban Construction School Beijing City UniversityBeijing 100083China

A calamitous landslide happened at 22:00 on September 1,2014 in the Yunyang area of Chongqing City,southwest China,enforcing the evacuation of 508 people and damaging 23 *** landslide volume comprised 1.44 million m^(3) of material in the source area and 0.4 million m^(3) of shoveled *** debris flow runout extended 400 m vertically and 1600 m *** Xianchi reservoir landslide event has been investigated as follows:(1)samples collected from the main body of landslide were carried out using GCTS ring shear apparatus;(2)the parameters of shear and pore water pressure have been measured;and(3)the post-failure characteristics of landslide have been analyzed using the numerical simulation *** excess pore-water pressure and erosion in the motion path are considered to be the key reasons for the long-runout motion and the scale-up of landslides,such as that at Xianchi,were caused by the heavy *** aim of this paper is to acquired numerical parameters and the basic resistance model,which is beneficial to improve simulation accuracy for hazard assessment for similar to potentially dangerous hillslopes in China and elsewhere.

关键词： geohazards landslide post-failure rapid and long runout ring shear test

Effects of gravel on the water absorption characteristics and hydraulic parameters of stony soil

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Journal of Arid Land 2024年第7期16卷 895-909页

作者： ma.yan WANG Youqi ma Chengfeng YUAN Cheng BAI Yiru Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China Ningxia UniversityYinchuan 750021China School of Geography and Planning Ningxia UniversityYinchuan 750021China School of Ecology and Environment Ningxia UniversityYinchuan 750021China

The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel,where gravel could affect the water movement process in the *** study focused on the effects of different gravel contents on the water absorption characteristics and hydraulic parameters of stony *** stony soil samples were collected from the eastern foothills of the Helan Mountains in April 2023 and used as the experimental materials to conduct a one-dimensional horizontal soil column absorption *** experimental groups with gravel contents of 0%,10%,20%,30%,40%,and 50%were established to determine the saturated hydraulic conductivity(K_(s)),saturated water content(θ_(s)),initial water content(θ_(i)),and retention water content(θ_(r)),and explore the changes in the wetting front depth and cumulative absorption volume during the absorption *** Philip model was used to fit the soil absorption process and determine the soil water absorption *** the length of the characteristic wetting front depth,shape coefficient,empirical parameter,inverse intake suction and soil water suction were derived from the van Genuchten ***,the hydraulic parameters mentioned above were used to fit the soil water characteristic curves,unsaturated hydraulic conductivity(K_(θ))and specific water capacity(C(h)).The results showed that the wetting front depth and cumulative absorption volume of each treatment gradually decreased with increasing gravel *** with control check treatment with gravel content of 0%,soil water absorption rates in the treatments with gravel contents of 10%,20%,30%,40%,and 50%decreased by 11.47%,17.97%,25.24%,29.83%,and 42.45%,*** the gravel content increased,inverse intake suction gradually increased,and shape coefficient,K_(s),θ_(s),andθ_(r)gradually *** the same soil water content,soil water suction and K_(θ)gradually decreased with increasing gravel *** the same soil water s

关键词： stony soil gravel content water absorption characteristics hydraulic parameters one-dimensional horizontal soil column absorption experiment van Genuchten model eastern foothills of Helan Mountains

Numerical simulation on directional solidification and heat treatment processes of turbine blades

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China Foundry 2024年第5期21卷 476-490页

作者： Ye-yuan Hu Ju-huai ma Qing-yan Xu School of materials Science and Engineering Tsinghua UniversityKey Laboratory for Advanced Materials Processing TechnologyMinistry of EducationBeijing 100084China

Study on turbine blades is crucial due to their critical role in ensuring the efficient and reliable operation of aircraft ***-based single crystal superalloys are extensively used in the hot manufacturing of turbine blades due to their exceptional high-temperature mechanical *** hot manufacturing of single crystal blades involves directional solidification and heat *** manufacturing of these blades is time-consuming,capital-intensive,and often insufficient to meet industrial *** simulation techniques have gained widespread acceptance in blade manufacturing research due to their low energy consumption,high efficiency,and rapid turnaround *** article introduces the modeling and simulation of hot manufacturing in single crystal *** discussion outlines the prevalent mathematical models employed in numerical simulations related to blade hot *** encapsulates the advancements in research concerning macro to micro-level numerical simulation techniques for directional solidification and heat treatment ***,potential future trajectories for the numerical simulation of single crystal blade hot manufacturing are also discussed.

关键词： single crystal blades Ni-based superalloy directional solidification heat treatment numerical simulation

Impacts of Roof/Ground Mitigation Strategies on Improving the Urban Thermal Environment and Human Comfort over the yangtze River Delta, China

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Journal of Meteorological Research 2024年第1期38卷 108-125页

作者： Hongyun ma Mi ZHANG Haishan CHEN yan WANG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)Nanjing University of Information Science&TechnologyNanjing 210044 School of Atmospheric Sciences Nanjing UniversityNanjing 210023 Experimental Teaching Center for Meteorology and Environment Nanjing University of Information Science&TechnologyNanjing 210044

The combined effects of global warming and the urban heat islands exacerbate the risk of urban heat stress. It is crucial to implement effective cooling measures in urban areas to improve the comfort of the thermal environment. In this study, the Weather Research and Forecasting Model(WRF), coupled with a single-layer Urban Canopy Model(UCM), was used to study the impact of heat mitigation strategies. In addition, a 5-km resolution land-cover dataset for China(ChinaLC), which is based on satellite remote sensing data, was adjusted and used, and 18 groups of numerical experiments were designed, to increase the albedo and vegetation fraction of roof/ground parameters. The experiments were conducted for four heatwave events that occurred in the summer of 2013 in the yangtze River Delta urban agglomeration of China. The simulated results demonstrated that, for the single roof/ground schemes, the mitigation effects were directly proportional to the albedo and greening. Among all the experimental schemes, the superposed schemes presented better cooling effects. For the ground greening scheme, with similar net radiation flux and latent heat flux, its storage heat was lower than that of the roof greening scheme, resulting in more energy flux into the atmosphere, and its daytime cooling effect was not as good as that of the roof greening scheme. In terms of human thermal comfort(HTC), the improvement achieved by the ground greening scheme was better than any other single roof/ground schemes, because the increase in the relative humidity was small. The comprehensive evaluation of the mitigation effects of different schemes on the thermal environment presented in this paper provides a theoretical basis for improving the urban environment through rational urban planning and construction.

关键词： urban heat island human thermal comfort urban canopy mitigation strategies yangtze River Delta Weather Research and Forecasting Model(WRF) Urban Canopy Model(UCM)

Synthetic host-guest pairs as novel bioorthogonal tools for pre-targeting

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Chinese Chemical Letters 2024年第2期35卷 44-56页

作者： yan-Long ma Shi yan Xiong-Jie Xu Hua Cao Ruibing Wang School of Chemistry and Chemical Engineering and Guangdong Cosmetics Engineering & Technology Research Center Guangdong Pharmaceutical UniversityZhongshan 528458China State Key Laboratory of Quality Research in Chinese Medicine and the Institute of Chinese Medical ScienceUniversity of MacaoMacao 999078China

Due to its simplicity, high efficiency, and chemo-selectivity, bioorthogonal chemistry has shown a great application potential in ***, four bioorthogonal pairs as targeting tools, including (strept)avidin/biotin, antibody/antigen, oligonucleotide hybridization and IEDDA tools, have been developed and applied in targeted ***, all of these tools still suffer from some limitations, such as difficult modification, biochemical fragility and larger molecular weight for biological association tools, as well as chemical instability for IEDDA *** host-guest pairs with relatively small molecular sizes not only possess strong chemical stability, but also have the features of fast conjugation rate, tunable binding affinity , easy modification, and high ***, they can be used as a novel non-covalent bioorthogonal tool for *** order to further promote the development of host-guest pairs as novel bioorthogonal tools for pre-targeted delivery, we firstly calculate their conversion rate to make researcher aware of their unique advantages;next, we summarize the recent research progress in this *** future perspectives and limitations of these unique tools will be *** review will provide a systemic overview of the development of synthetic host-guest pairs as novel bioorthogonal tools for pre-targeting, and may serve as a “go for” resort for researchers who are interested in searching for new synthetic tools to improve pre-targeting.

关键词： Bioorthogonal chemistry Synthetic host-guest pairs Pre-targeting Molecular recognition Biomedical applications

UiO-66-NH_(2)nanoparticles supported on layered double hydroxides as an excellent adsorbent for levofloxacin capture

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Particuology 2024年第9期92卷 155-165页

作者： yan Li Heng Lin Qiaolan Yu Na ma Wei Dai College of Geography and Environmental Sciences Zhejiang Normal UniversityJinhua321004China Key Laboratory of the Ministry of Education for Advanced Catalysis materials College of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua321004China

The adsorption performances of individual adsorbent such as UiO-66-NH_(2)and MgAl-layered double hydroxides(MgAl-LDH)toward levofloxacin(LVX)is less satisfactory due to the disappointing uptake capacity and adsorption ***,a 3D flower-like composite adsorbent prepared via iterative hydrothermal synthesis method anchoring UiO-66-NH_(2)nanoparticles onto the MgAl-LDH *** to the synergistic effects of UiO-66-NH_(2),and MgAl-LDH,the MgAl-LDH@UiO-66-NH_(2)exhibits an outstanding adsorption performance toward ***,the maximum LVX uptake capacity over MgAl-LDH@UiO-66-NH_(2)reached 268 mg/g,which was higher than that of the individual adsorption materials UiO-66-NH_(2)(41 mg/g),MgAl-LDH(140 mg/g),and some adsorbents reported in previous *** rapid adsorption process can reach equilibrium within 20 min,which conformed well to the pseudo-second-order kinetics and the Langmuir isotherm *** thermodynamic result also indicated that the adsorption was spontaneous and exothermic,simultaneous coexisting physical and chemical adsorption ***,the MgAl-LDH@UiO-66-NH_(2)still maintained excellent adsorption capacity with a slightly decrease after fifth cycle,exhibiting a remarkable reuse and stable *** work provides a highly novel strategy to prepare recyclable composite adsorbent for the LVX capture from aqueous solution.

关键词： Layered double hydroxides UiO-66-NH_(2) LVX Adsorption

Metal-organic framework-derived CoSe_(2)@N-doped carbon nanocubes for high-performance lithium-ion capacitors

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Rare Metals 2024年第5期43卷 2150-2160页

作者： Lei Wang Xiong Zhang yan-yan Kong Chen Li Ya-Bin An Xian-Zhong Sun Kai Wang yan-Wei ma Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China School of Engineering Sciences University of Chinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering and Advanced Electromagnetic Drive Technology Qilu ZhongkeJinan 250013China School of materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China

Cobalt selenide(CoSe_(2))has garnered considerable attention as a prospective anode candidate for advanced lithium-ion storage,prompting comprehensive ***,CoSe_(2)-based anodes usually suffer from significant volume variation upon lithiation leading to unsatisfactory cycling ***,a versatile synthesis route is proposed for the in-situ fabrication of CoSe2nanoparticles embedded in N-dope carbon skeleton(CoSe_(2)@NC)through annealing treatment and selenization of a metal–organic framework-derived(MOF)*** N-doped carbon derived from the MOF serves not only as an excellent conductive substrate but also as a confined reactor,effectively inhibiting the structural instability and alleviating the inevitable volume change of CoSe_(2).Owing to their unique nanostructure,the as-prepared CoSe_(2)@NC exhibits a high capacity of 745.9mah·g^(-1)at 0.1 A·g^(-1),while maintaining excellent rate capability and an impressive ***,the assembled lithium-ion capacitor(LIC)based on CoSe_(2)@NC demonstrates an energy density of 130Wh·kg^(-1),a power density of 24.6 kW·kg^(-1),and remarkable capacity retention of 90.8%after 8000 *** results highlight the great potential of CoSe_(2)@NC for practical applications.

关键词： Lithium capacitors Cobalt selenide Metal-organic frameworks N-doped carbon

Lightweight Si_(3)N_(4)@SiO_(2) ceramic foam for thermal insulation and electromagnetic wave transparency

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Nano Research 2024年第5期17卷 4298-4306页

作者： Zongwei Tong Xiangjie yan Yuexiang Wang Kexun Li Weihai ma China-Blarus Belt and Road Joint Laboratory on Electromagnetic Environment Effect the 33rd Research Institute of ChinaElectronics Technology Group CorporationTaiyuan 030032China Key Laboratory for Advanced Ceramics and machining Technology of Ministry of Education School of Material Science and EngineeringTianjin UniversityTianjin 300072China Department of materials Science and Engineering Jinzhong UniversityJinzhong 030619China

Increasing porosity is one of the most direct ways to improve the thermal insulation and dielectric properties of *** now,many wet methods for preparing Si_(3)N_(4) ceramic foams usually face the problems of complex rheology,long period,and expensive cost,and the reported pore sizes of Si_(3)N_(4) ceramic foams are typically micron-grade,resulting in a lack of competitiveness in thermal insulation and wave-transparent *** this paper,the Si_(3)N_(4)@SiO_(2) ceramic foams were prepared using an efficient dry-method,which combined three processes of low temperature chemical vapor deposition(LTCVD),template,and isostatic *** method has the advantages of simple operation and short preparation period,and can realize near-net size molding and mass *** addition,the evolution mechanisms of honeycomb microstructure and composition of Si_(3)N_(4)@SiO_(2) ceramic foam during sintering were studied by chemical reaction *** as-prepared Si_(3)N_(4)@SiO_(2) ceramic foam possesses low density(0.377 g·cm^(-3)),high compressive strength(7.5 MPa),low thermal conductivity(0.0808 W·m^(-1)·K^(-1)),and excellent dielectric properties(εmaximum working temperature in air can reach up to 1100℃.It will be recommended to be applied in the interlayer of Si_(3)N_(4) ceramic radome to improve its thermal insulation and electromagnetic wave transparency performances.

关键词： silicon nitride ceramic foam honeycomb microstructure dielectric properties thermal insulation

Research on casing deformation prevention technology based on cementing slurry system optimization

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Petroleum Science 2024年第2期21卷 1231-1240页

作者： yan yan Meng Cai Wen-Hai ma Xiao-Chuan Zhang Li-Hong Han Yong-Hong Liu State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment materials CNPC Tubular Goods Research InstituteXi©an710077ShaanxiChina College of Mechanical and Electrical Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province Chengdu610095SichuanChina CNPC Daqing Oilfield Company Daqing163453HeilongjiangChina

The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%.

关键词： Cement slurry Hollow ceramsite Casing deformation Formation slip Field test