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Journal of Materials Science & Technology 2022年第20期115卷 199-207页

作者： weijie zhang Xizhong Zhou Jinzhao Huang Shouwei zhang Xijin Xu School of Physics and Technology University of JinanJinan 250022China

Improving the separation efficiency of photogenerated carriers and broadening the light absorption range of the photocatalyst are two important factors for improving the performance of the *** this paper,a new and efficient Z-scheme Cd S/iron phthalocyanine(Cd S/Fe Pc)core-shell nanostructure composite material is prepared by a simple solid-phase reaction *** are two key points in the preparation of composite materials:one is that hydrogen bonding energy is closely connected with Fe Pc,another is that Fe Pc can be uniformly assembled on Cd S *** photocatalytic hydrogen evolution(PHE)of the Cd S/Fe Pc nanocomposite(73.01μmol/h)is 2.6 times higher than that of pure Cd S(26.67μmol/h).In addition,after 4 photocatalytic cycles,the PHE of the Cd S/Fe Pc composite is still 92.3%of the first *** are three reasons for this situation:(1)The Z-scheme heterojunction is formed to improve the separation efficiency of photogenerated carriers;(2)Fe Pc expands the visible light absorption range of Cd S;(3)The large core-shell contact area is favorable for the separation of photo-induced carriers at the *** research is conducive to the further development of new photocatalytic materials with high efficiency,low cost and simple preparation.

关键词： CdS/FePc Core-shell nanostructure Photocatalytic hydrogen evolution Z-scheme heterojunction

Polarimetric whitening filter for POLSAR image based on subspace decomposition

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Journal of Systems Engineering and Electronics 2008年第6期19卷 1121-1126页

作者： Yang Jian Deng Qiming Huangfu Yue zhang weijie Dept. of Electronics Engineering Tsinghua Univ. Beijing 100084 P. R. China

Speckle filtering is an indispensable pre-processing step for applications of polarimetric synthetic aperture radar （POLSAR）, such as terrain classification, target detection, etc. As one of the most typical methods, the polarimetric whitening filter （PWF） can be used to produce a minimum-speckle image by combining the complex elements of the scattering matrix, but polarimetric information is lost after the filtering process. A polarimetric filter based on subspaze decomposition which was proposed by Cu et al specializes in retrieving principle scattering characteristics, but the corresponding mean value of an image after filtering is not kept well. A new filter is proposed for improving the disadvantage based on subspace decomposition. Under the constraint that a weighted combination of the polarimetric SAR images equals to the output of the PWF, the Euclidean distance between an unfiltered parameter vector and a signal space vector is minimized so that noises can be reduced. It is also shown that the proposed method is equivalent to the subspace filter in the case of no constraint. Experimental results with the NASA/JPL airborne polarimetric SAR data demonstrate the effectiveness of the proposed method.

关键词： speckle filtering synthetic aperture radar polarimetric polarimetric whitening filter subspace decomposition

Spatial variability effect of internal friction angle on the post-failure behavior of landslides using a random and non-Newtonian fluid based SPH method

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Geoscience Frontiers 2020年第4期11卷 1107-1121页

作者： weijie zhang Jian Ji Yufeng Gao Xiaoyu Li Chunshun zhang Key Lab of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China Department of Civil Engineering Monash UniversityClayton3168Australia

This study proposed a random Smoothed Particle Hydrodynamics method for analyzing the post-failure behavior of landslides,which is based on the Karhunen-Loeve(K-L) expansion,the non-Newtonian fluid model,and the OpenMP parallel ***,the applicability of this method was validated by comparing the generated random field with theoretical result and by simulating the post-failure process of an actual ***,an illustrative landslide example was created and simulated to obtain the spatial variability effect of internal friction angle on the post-failure behavior of landslides under different coefficients of variation(COVs) and correlation lengths(CLs).As a conclusion,the reinforcement with materials of a larger friction angle can reduce the runout distance and impact the force of a *** the increase of COV,the distribution range of influence zones also increases,which indicates that the deviation of influence zones becomes *** addition,the correlation length in Monte Carlo simulations should not be too small,otherwise the variation range of influence zones will be underestimated.

关键词： Landslides Spatial variability Random field Smoothed particle hydrodynamics Monte Carlo simulation Post-failure behavior

Design of cobalt-based catalysts with the uniformly distributed coreshell structure for ultra-efficient activation of peroxymonosulfate for tetracycline degradation

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Journal of Materiomics 2023年第5期9卷 882-891页

作者： Hongjie Qin weijie zhang Qiling Zheng Penghui zhang Shouwei zhang Xijin Xu School of Physics and Technology University of Jinan336 West Road of Nan XinzhuangJinan250022ShandongChina

Catalysts that can rapidly degrade tetracycline(TC)in water without introducing secondary ion pollution have always been ***,a cobalt-based catalyst(CoO_(x)@P-C)is prepared so that CoOx quantum particles(5e10 nm)are uniformly distributed on a linear substrate,and the outer layer is covered with a shell(P-C).The quantum particles of CoO_(x) provide many active sites for the reaction,which ensures the efficient degradation effect of the catalyst,and 30 mg/L TC can be completely degraded in only 5 *** shell of the quantum particles'outer layer can effectively reduce ions'*** combination of the shell-like structure and the linear substrate greatly enhances the catalysis's stability and ensures that the catalyst is prepared into a film for practical *** high catalytic activity of CoO_(x)@P-C is mainly due to the following factors:(1)Uniformly distributed ultra-small nanoparticles can provide many active sites.(2)The microenvironment formed by the core-shell structure enhances not only catalytic stability but also provides the driving force to improve the reaction rate.(3)The composite of CoO_(x) and P-C core-shell structure can accelerate electron transfer and generate many reactive oxygen species in a short time,which makes TC degrade extremely rapidly.

关键词： Cobalt quantum particles Peroxymonosulfate(PMS)activation Superoxide Core-shell structure Tetracycline

Mapping bone marrow niches of disseminated tumor cells

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Science China(Life Sciences) 2017年第10期60卷 1125-1132页

作者： weijie zhang Hin Ching Lo Xiang H.-F.zhang Lester and Sue Smith Breast Center Baylor College of Medicine Houston TX 77030 USA Dan L. Duncan Cancer Center Baylor College of Medicine Houston TX 77030 USA Department of Molecular and Cellular Biology Baylor College of Medicine Houston TX 77030 USA Graduate Program in Integrative Molecular and Biomedical Sciences Baylor College of Medicine Houston TX 77030 USA McNair Medical Institute Baylor College of Medicine Houston TX 77030 USA

Breast cancer cells may disseminate early, before tumor diagnosis. Disseminated tumor cells, or DTCs, reside in the bone marrow, and may persist for years or even decades. Some of these cells may be re-activated to resume aggressive growth, and eventually become overt bone metastases. Recent studies have begun to shed light on this complicated process and revealed multiple steps and intermediate states of colonizing DTCs. However, how cancer-host interactions evolve during this process needs to be further understood. Most of our current knowledge of the bone microenvironment is obtained through studies looking for the hematopoietic stem cell(HSC) niche. Although this long-standing question has not yet been resolved, our search for the HSC niche has resulted in a detailed map of various cell types in the bone marrow. Furthermore, various techniques used to find the HSC niche may also be adapted for finding the cancer cell niche. In this article, we will review the recent progress in both the DTC and HSC areas with a focus on their potential microenvironment niches. We will also discuss how to apply what we have learned from HSC studies to map DTCs in the bone context. We hope to stimulate thoughts and ideas to further elucidate the bone colonization process, and develop potential therapeutic interventions.

关键词： disseminated tumor cells bone marrow niches hematopoietic stem cell niches 3D imaging

On Finite Word Length Computing Error of Fixed-Point SAR Imaging Processing

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Chinese Journal of Electronics 2014年第3期23卷 645-648页

作者： XIE Yizhuang ZHU Bocheng YAN Wen zhang weijie School of Information and Electronics Beijing Institute of Technology School of Electronics Engineering and Computer Science Peking University

Synthetic aperture radar(SAR) imaging system is generally realized by fixed-point with the purpose of reducing system implementation scale and enhancing real-time performance. Finite word length computing error of fixed-point SAR imaging system is studied. The characteristic of computing error in SAR imaging system is analyzed. A finite word length computing error model of SAR imaging system is built, by means of which the empirical formula of system’s output noise-to-signal ratio is derived. Based on the empirical formula, SAR imaging system processing word length is presented according to different processing granularities. The validity of this proposed finite word length computing error model of SAR imaging system is verified by system level fixed-point simulation.

关键词： Synthetic aperture radar(SAR) imaging Finite word length Analysis of computing error

High-Order Positivity-Preserving Well-Balanced Discontinuous Galerkin Methods for Euler Equations with Gravitation on Unstructured Meshes

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Communications in Computational Physics 2022年第3期31卷 771-815页

作者： weijie zhang Yulong Xing Yinhua Xia Yan Xu School of Mathematical Sciences University of Science and Technology of ChinaHefeiAnhui 230026P.R.China Department of Mathematics The Ohio State UniversityColumbusOH 43210USA

In this paper,we propose a high-order accurate discontinuous Galerkin(DG)method for the compressible Euler equations under gravitationalfields on un-structured *** scheme preserves a general hydrostatic equilibrium state and provably guarantees the positivity of density and pressure at the same ***-ing with the work on the well-balanced scheme for Euler equations with gravitation on rectangular meshes,the extension to triangular meshes is conceptually plausible but highly *** introduce a special way to recover the equilibrium state and then design a group of novel variables at the interface of two adjacent cells,which plays an important role in the well-balanced and positivity-preserving *** main challenge is that the well-balanced schemes may not have the weak positivity *** order to achieve the well-balanced and positivity-preserving properties simultaneously while maintaining high-order accuracy,we carefully design DG spa-tial discretization with well-balanced numericalfluxes and suitable source term *** the ideal gas,we prove that the resulting well-balanced scheme,cou-pled with strong stability preserving time discretizations,satisfies a weak positivity property.A simple existing limiter can be applied to enforce the positivity-preserving property,without losing high-order accuracy and *** one-and two-dimensional numerical examples demonstrate the desired properties of the pro-posed scheme,as well as its high resolution and robustness.

关键词： Discontinuous Galerkin methods Euler equations gravitational field positivity-preserving well-balanced triangular mesh

Late Carboniferous to early Permian sedimentaryetectonic evolution of the north of Alxa, Inner Mongolia, China： Evidence from the Amushan Formation

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Geoscience Frontiers 2016年第5期7卷 733-741页

作者： Haiquan Yin Hongrui Zhou weijie zhang Xiaoming Zheng Shengyu Wang China University of Geosciences Beijing 100083 PR China China Non-ferrous Metals Resource Geological Survey Beijing 100012 PR China

The late Paleozoic evolution of the Wulijishanhen（WSH）-Shangdan（SD） area near to the Chaganchulu Ophiolite belt is reinterpreted. Analysis of the upper Carboniferous to lower Permian sedimentary sequence, biological associations, detrital materials, sandstone geochemistry and volcanic rocks indicates that the SD area was an epicontinental sea and rift during the late Paleozoic rather than a large-scale ocean undergoing spreading and closure. This study reveals that the actual evolution of the study area is from the late Carboniferous to the early Permian. The fusulinids Triticites sp. and Pseudoschwagerina *** the limestones demonstrate that the Amushan Formation develops during the late Carboniferous to the early Permian. The limestones at the base of the SD section indicate that it is a stable carbonate platform environment, the volcanic rocks in the middle of the sequence support a rift tectonic background, and the overlying conglomerates and sandstones are characteristic of an epicontinental sea or marine molasse setting. The rift volcanism made the differences in the fossil content of the SD and WSH sections and led to two sections expose different levels within the Amushan Formation and different process of tectonic evolution. Moreover, the geochemical characteristics and detrital materials of the sandstones show that the provenance and formation of the sandstones were related to the setting of active continental margin. The quartz-feldspar-lithic fragments distribution diagram indicates that the material source for the sandstones was a recycled orogenic belt. Thus, the source area of the sandstones may have been an active continental margin before the late Carboniferouseearly Permian. The characteristics of the regional tectonic evolution of the area indicate that the region may form a small part of the Gobie Tianshan rift of southern Mongolia.

关键词： Alxa Central Asian Orogenic Belt Foraminifera Amushan Formation Sedimentary sequence Geochemistry

Route selection for opportunity-sensing and prediction of waterlogging

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Frontiers of Computer Science 2024年第4期18卷 147-159页

作者： Jingbin WANG weijie zhang Zhiyong YU Fangwan HUANG Weiping ZHU Longbiao CHEN College of Computer and Data Science Fuzhou UniversityFuzhou 350108China Department of Computer Science and Technology Xiamen UniversityXiamen 361005China

Accurate monitoring of urban waterlogging contributes to the city’s normal operation and the safety of residents’daily ***,due to feedback delays or high costs,existing methods make large-scale,fine-grained waterlogging monitoring impossible.A common method is to forecast the city’s global waterlogging status using its partial waterlogging *** method has two challenges:first,existing predictive algorithms are either driven by knowledge or data alone;and second,the partial waterlogging data is not collected selectively,resulting in poor *** overcome the aforementioned challenges,this paper proposes a framework for large-scale and fine-grained spatiotemporal waterlogging monitoring based on the opportunistic sensing of limited bus *** framework follows the Sparse Crowdsensing and mainly comprises a pair of iterative predictor and *** predictor uses the collected waterlogging status and the predicted status of the uncollected area to train the graph convolutional neural *** combines both knowledge-driven and data-driven approaches and can be used to forecast waterlogging status in all regions for the upcoming *** selector consists of a two-stage selection procedure that can select valuable bus routes while satisfying budget *** experimental results on real waterlogging and bus routes in Shenzhen show that the proposed framework could easily perform urban waterlogging monitoring with low cost,high accuracy,wide coverage,and fine granularity.

关键词： waterlogging prediction sparse crowdsensing active learning route selection graph convolutional network

Tunable electronic band structure,luminescence properties and thermostability of(Gd_(1-x)La_(x))_(2)Si_(2)O_(7):Ce scintillator by adjusting La/Gd ratio

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Journal of Rare Earths 2021年第6期39卷 657-665,I0002页

作者： Qinhua Wei Zhenzhen Zhou weijie zhang Gao Tang Qian Liu Laishun Qin Hongsheng Shi College of Materials and Chemistry China Jiliang UniversityHangzhou 310018China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Xinjiang Technical Institute of Physics&Chemistry Chinese Academy of SciencesUrumqi 830011China

Mixed crystal strategy is an effective approach of improving the luminescence properties of optical materials and has been adopted widely in many *** this paper,the La-mixed Gd_(2)Si_(2)O_(7):Ce polycrystalline samples were successfully synthesized by a sol-gel *** crystal structure and luminescence properties were confirmed and discussed by XRD,UV-Vis luminescence spectra,and XEL,*** vacuum ultraviolet excitation spectra and thermoluminescence glow curves were also systematically investigated and discussed at varied temperature.A combination of the first-principles calculations and optical characterization experiments was employed to study the electronic band structure of host material,revealing that the band gap is narrowed and the 5d_(1) level of Ce^(3+) shifts to higher energy as the La content *** luminescence the rmo-stability and activation energy were also measured and *** indicates that thermo-stability is strongly dependent on the La *** effective approach is developed to tune the electronic band structure,luminescence properties and thermostability of(Gd_(1-x)La_(x))_(2)Si_(2)O_(7):Ce scintillator by adjusting La/Gd ratio.

关键词： First-principles calculations Scintillator (Gd_(1-x)La_(x))_(2)Si_(2)O_(7):Ce Band structure tunable Luminescence properties Rare earths