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Improving the accuracy of precipitation estimates in a typical inland arid area of China using a dynamic Bayesian model averaging approach

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Journal of Arid Land 2024年第3期16卷 331-354页

作者： xu wenjie DING Jianli BAO Qingling WANG Jinjie xu Kun College of Geography and Remote Sensing Sciences Xinjiang UniversityUrumqi 830017China Key Laboratory of Smart City and Environment Modelling of Higher Education Institute Xinjiang UniversityUrumqi 830017China

Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water *** and integrating precipitation datasets from different sources to accurately characterize precipitation patterns has become a challenge to provide more accurate and alternative precipitation information for the region,which can even improve the performance of hydrological *** study evaluated the applicability of widely used five satellite-based precipitation products(Climate Hazards Group InfraRed Precipitation with Station(CHIRPS),China Meteorological Forcing Dataset(CMFD),Climate Prediction Center morphing method(CMORPH),Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record(PERSIANN-CDR),and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA))and a reanalysis precipitation dataset(ECMWF Reanalysis v5-Land Dataset(ERA5-Land))in Xinjiang using ground-based observational precipitation data from a limited number of meteorological *** on this assessment,we proposed a framework that integrated different precipitation datasets with varying spatial resolutions using a dynamic Bayesian model averaging(DBMA)approach,the expectation-maximization method,and the ordinary Kriging interpolation *** daily precipitation data merged using the DBMA approach exhibited distinct spatiotemporal variability,with an outstanding performance,as indicated by low root mean square error(RMSE=1.40 mm/d)and high Person's correlation coefficient(CC=0.67).Compared with the traditional simple model averaging(SMA)and individual product data,although the DBMA-fused precipitation data were slightly lower than the best precipitation product(CMFD),the overall performance of DBMA was more *** error analysis between DBMA-fused precipitation dataset and the more advanced Inte

关键词： precipitation estimates satellite-based and reanalysis precipitation dynamic Bayesian model averaging streamflow simulation Ebinur Lake Basin Xinjiang

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Designed imidazole-based supramolecular catalysts for accelerating oxidation/hydrolysis cascade reactions

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Nano Research 2024年第6期17卷 4916-4923页

作者： Yuanxi Liu wenjie xu Shichao xu Haifeng Wu Baoli Zhang Li Song Zhen-Gang Wang State Key Laboratory of Organic-Inorganic Composites Key Lab of Biomedical Materials of Natural Macromolecules(Ministry of Education)Beijing Laboratory of Biomedical MaterialsCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China National Synchrotron Radiation Laboratory CAS Center for Excellence in NanoscienceUniversity of Science and Technology of ChinaHefei 230029China

Reconstructing enzymatic active sites presents a significant challenge due to the intricacies involved in achieving enzyme-like scaffold folding and spatial arrangement of essential functional *** is also a growing interest in building biocatalytic networks,wherein multiple enzymatic active sites are localized within a single artificial system,allowing for cascaded *** this work,we report the self-assembly of imidazole or its derivatives with fluorenylmethyloxycarbonyl-modified histidine and Cu2+to fabricate a supramolecular catalyst,which possesses catechol oxidase-like dicopper center with multiple imidazole as the coordination *** electron microscopy,low-temperature X-band continuous-wave electron paramagnetic resonance,K-edge X-ray absorption spectra/the extended X-ray absorption fine structure analysis,and density functional theory modeling were used for the structural characterization of the *** phenol derivatives and the dissolved oxygen were used as the substrates,with the addition of 4-aminoantipyrine to generate a red adduct with a maximum absorbance at 510 nm,for obtaining time-dependent absorbance change curves and estimating the *** results reveal that the addition of imidazole synergistically accelerates the oxidative activity about 10-fold and the hydrolysis activity about 14-fold than fluorenylmethyloxycarbonyl modified-histidine/Cu2+.The supramolecular nanoassembly also exhibits the ability to catalyze oxidation/hydrolysis cascade reactions,converting 2′,7′-dichlorofluorescin diacetate into 2′,7′-*** process can be regulated through the methylation of the imidazole component at various *** work may contribute to the design of advanced biomimetic catalysts,and shed light on early structural models of the active sites of the primitive copper-dependent enzymes.

关键词： enzyme mimic self-assembly supramolecular catalyst cascade reactions

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Investigation on mechanical properties regulation of rock-like specimens based on 3D printing and similarity quantification

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International Journal of Mining Science and Technology 2024年第5期34卷 573-585页

作者： Duanyang Zhuang Zexu Ning Yunmin Chen Jinlong Li Qingdong Li wenjie xu Center for Hypergravity Experiment and Interdisciplinary Research Zhejiang UniversityHangzhou 310058China MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou 310058China

3D printing is widely adopted to quickly produce rock mass models with complex structures in batches,improving the consistency and repeatability of physical *** is necessary to regulate the mechanical properties of 3D-printed specimens to make them proportionally similar to natural *** study investigates mechanical properties of 3D-printed rock analogues prepared by furan resin-bonded silica sand *** mechanical property regulation of 3D-printed specimens is realized through quantifying its similarity to sandstone,so that analogous deformation characteristics and failure mode are *** similarity conversion,uniaxial compressive strength,cohesion and stress–strain relationship curve of 3D-printed specimen are similar to those of *** the study ranges,the strength of 3D-printed specimen is positively correlated with the additive content,negatively correlated with the sand particle size,and first increases then decreases with the increase of curing *** regulation scheme with optimal similarity quantification index,that is the sand type of 70/140,additive content of 2.5‰and curing temperature of 81.6℃,is determined for preparing 3D-printed sandstone analogues and *** effectiveness of mechanical property regulation is proved through uniaxial compression contrast *** study provides a reference for preparing rock-like specimens and engineering models using 3D printing technology.

关键词： 3D printing Mechanical property regulation Similarity quantification Rock analogue Sandstone

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Nano-silica modified lightweight and high-toughness carbon fiber/phenolic ablator with excellent thermal insulation and ablation performance

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Defence Technology（防务技术） 2024年第1期31卷 192-199页

作者： wenjie xu Wenda Song Xianfeng Jia Cheng Ma Jitong Wang Wenming Qiao Licheng Ling State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China School of Chemical Engineering and Materials Changzhou Institute of TechnologyChangzhou 213032China Key Laboratory of Specially Functional Polymeric Materials and Related Technology(Ministry of Education) School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

Lightweight and high-toughness carbon fiber/phenolic ablator(CFPA)is required as the Thermal Protection System(TPS)material of aerospace vehicles for next-generation space *** improve the ablative properties,silica sol with good particle size distribution prepared using tetramethoxysilane(TMOS)was blended with natural rubber latex and deposited onto carbon fiber felt,which was then integrated with phenolic aerogel matrix,introducing nano-silica into the framework of *** modified CFPA with a low density of 0.28—0.31 g/cm3exhibits strain-in-fracture as high as 31.2%and thermal conductivity as low as 0.054 W/(m·K).Furthermore,a trace amount of nano-silica could effectively protect CFPA from erosion of oxidizing atmosphere in different high-temperature *** oxyacetylene ablation test of 3000°C for 20 s shows a mass ablation rate of 0.0225 g/s,a linear ablation rate of 0.209 mm/s for the modified CFPA,which are 9.64%and 24.82%lower than the unmodified ***,the long-time butane ablation test of 1200°C for 200 s shows an insignificant recession with mass and linear ablation rate of 0.079 g/s and 0.039 mm/s,16.84%and 13.33%lower than the unmodified ***,the fixed thermocouple in the test also demonstrates a good thermal insulation performance with a low peak back-face temperature of 207.7°C,12.25%lower than the unmodified ***,the nano-silica modified CFPA with excellent overall performance presents promising prospects in high-temperature aerospace applications.

关键词： Nano-silica Carbonfiber Phenolic aerogel Insulation Ablation

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Atomic-resolution Interfacial Microstructure and Thermo-electro-magnetic Energy Conversion Performance of Gd/Bi0.5Sb1.5Te3 Composites

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Energy & Environmental Materials 2024年第4期7卷 355-363页

作者： Chengshan Liu wenjie xu Ping Wei Shaoqiu Ke Wenjun Cui Longzhou Li Dong Liang Xianfeng Ye Tiantian Chen Xiaolei Nie Wanting Zhu Wenyu Zhao Qingjie Zhang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory

Thermo-electro-magnetic materials with simultaneously large magnetocaloric(MC) and thermoelectric (TE) effects are the core part for designing TE/MC all-solid-state cooling *** MC phase with TE material is an effective ***,the elemental diffusion and chemical reaction occurring at the two-phase interfaces could significantly impair the cooling performance.

关键词： interfacial reaction magnetocaloric performance thermoelectric performance thermo-electro-magnetic materials

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Feasibility analysis of hypergravity experiment of density-driven convection of dissolved CO

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Journal of Earth Science 2024年

作者： Ruiqi Chen wenjie xu Yingtao Hu Yunmin Chen Jinlong Li Duanyang Zhuang Center for Hypergravity Experimental and Interdisciplinary Research， Zhejiang University MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering， Zhejiang University School of Engineering， Hangzhou City University

Dissolution trapping is one of the most promising mechanisms for safe geological carbon storage. Density-driven convection substantially accelerates the conversion of free-phase CO2to the dissolved state， enhancing the sequestration safety. Since this process occurs on time scales of hundreds to thousands of years， reproducing it through conventional laboratory physical model tests is challenging. The hypergravity experiment reduces the model size and shortens the experimental time， enabling the modeling of gravity-driven flow processes at the field scale. However， it is uncertain whether the preferential flow effect caused by fractures can be reproduced in a hypergravity experiment. In this study， a three-dimensional discrete fracture-matrix model （3D-DFM） was used to evaluate the feasibility of hypergravity experiment of the transport of dissolved CO2in fractured *** hypergravity tests were performed to examine the feasibility of modeling density-driven convection in homogeneous and heterogeneous media at different centrifuge accelerations. The hypergravity experiment can be used to study density-driven convection of dissolved CO2at the field scale in homogeneous system. The numerical results show that the hypergravity experiment enables a faster breakthrough of plume and overestimates CO2migration in the matrix surrounding the fractures.

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一种改进组合加权的TDOA室内二维定位算法

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电讯技术 2024年第6期64卷 936-944页

作者：徐文杰张贞凯江苏科技大学海洋学院江苏镇江212028

针对现有组合加权算法对定位区域边缘的目标定位时精度较低的问题,在现有组合加权算法的基础上提出了一种改进算法。首先,将基站分组,以到达时差算法得到目标位置的多个估计结果;其次,计算各估计结果之间距离值并排序,以滑动窗口法判断... 详细信息

针对现有组合加权算法对定位区域边缘的目标定位时精度较低的问题,在现有组合加权算法的基础上提出了一种改进算法。首先,将基站分组,以到达时差算法得到目标位置的多个估计结果;其次,计算各估计结果之间距离值并排序,以滑动窗口法判断是否存在基站组出现异常定位估计;最后,当任意基站组的定位结果发生异常时,使用目标位置估计结果及其估计克拉美罗下界值设计两个加权步骤的权值,通过二步组合加权算法得到最终定位结果。仿真结果表明,所提算法有效减少了原组合加权算法对定位区域边缘的目标定位时的误差,当测量噪声标准差为0.8 m时,所提算法相较于原算法在正方形边缘区域定位均方根误差减小了0.35 m;在定位狭窄矩形区域时,所提算法平均定位均方根误差减小了0.11 m。

关键词：室内二维定位目标定位到达时间差(TDOA) 组合加权算法

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小行星撞遇陆地成坑动力学的计算模拟

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深空探测学报（中英文） 2024年第2期11卷 195-202页

作者：徐文杰刘芹芹申旭辉清华大学水圈科学与水利工程全国重点实验室北京100084 中国科学院国家空间科学中心空间天气学国家重点实验室北京100190 中国科学院国家空间科学中心太阳活动与空间天气重点实验室北京100190

小行星撞遇陆地是一个复杂的非线性动力学过程,难以通过模型试验的方法开展相关研究。数值计算为这一灾害动力学过程分析提供了重要的工具,基于自主研发的CoSim软件中离散元(Discrete Element Method,DEM)模块初步实现了小行星撞遇陆地... 详细信息

小行星撞遇陆地是一个复杂的非线性动力学过程,难以通过模型试验的方法开展相关研究。数值计算为这一灾害动力学过程分析提供了重要的工具,基于自主研发的CoSim软件中离散元(Discrete Element Method,DEM)模块初步实现了小行星撞遇陆地的大规模计算模拟。基于小行星撞遇陆地三维动力学全过程的数值仿真结果:实现了初始接触、撞遇挖掘、高速抛射和回落调整4个撞击阶段全过程仿真;小行星的碰撞入射角及撞遇过程中动力学行为将影响撞击坑的地形地貌特征。研究也表明大规模数值计算方法可较好地实现小行星撞遇地球这一动力学过程,为小行星防御提供支撑。

关键词：小行星撞击坑离散元法数值仿真

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Erratum to:Designed imidazole-based supramolecular catalysts for accelerating oxidation/hydrolysis cascade reactions

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Nano Research 2024年第7期17卷 6773-6773页

Erratum to Nano Research,2024,17(6):4916−4923 https://***/10.1007/s12274-024-6489-5 Labeling and statement of equal contribution of the authors Yuanxi Liu and wenjie xu were missed in the original article as well as the Electronic Supplementary *** symbols of equal contribution“§”were added to both authors in the author list,and their contribution was stated as follows:“§Yuanxi Liu and wenjie xu contributed equally to this work.”

关键词： hydrolysis stated statement

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清宫唐卡装镶样式的分类及演变

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紫禁城 2024年第8期 80-97页

作者：许文婕故宫博物院文保科技部综合管理组

在乾隆朝,由乾隆皇帝主导,唐卡的装镶形式由藏地风格逐渐吸收内地审美和书画装裱特色,形成了特有的清宫唐卡装镶样式。从清宫典型唐卡的镶边牙子用料、尺寸、红白小线、包首和撞边等变化, 或可一窥清宫唐卡装镶样式的演变过程和其形成... 详细信息

在乾隆朝,由乾隆皇帝主导,唐卡的装镶形式由藏地风格逐渐吸收内地审美和书画装裱特色,形成了特有的清宫唐卡装镶样式。从清宫典型唐卡的镶边牙子用料、尺寸、红白小线、包首和撞边等变化, 或可一窥清宫唐卡装镶样式的演变过程和其形成的原因。

关键词：唐卡书画装裱乾隆朝乾隆皇帝牙子形成的原因清宫演变过程

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