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电化学置换反应制备石墨烯基纳米无定型锑复合阳极用于高性能钠离子电容器的构筑
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作者 米超林 秦玉莹 +6 位作者 黄欣莉 罗伊杰 张志薇 王成祥 石元昌 尹龙卫 王儒涛 《物理化学学报》 SCIE CAS CSCD 北大核心 2024年第5期24-27,共4页
锑(Sb),因其具有较高的理论比容量(660 mAh·g^(-1))、较低储钠电位(0.5–0.8 V vs.Na/Na^(+))和较高的密度(6.68 g·cm^(-3))等特点,被认为是一种理想的钠离子电容器的阳极材料。然而,在Na^(+)脱嵌过程中,Sb电极会发生较大的... 锑(Sb),因其具有较高的理论比容量(660 mAh·g^(-1))、较低储钠电位(0.5–0.8 V vs.Na/Na^(+))和较高的密度(6.68 g·cm^(-3))等特点,被认为是一种理想的钠离子电容器的阳极材料。然而,在Na^(+)脱嵌过程中,Sb电极会发生较大的体积变化,导致其容量快速衰减以及倍率性能变差,阻碍了Sb电极的实际应用。因此,本文提出一种可用于制备锚定在具有碳涂层的二维石墨烯表面的无定型Sb纳米颗粒的电化学置换方法。所制备Sb/石墨烯复合材料具有典型的二维复合结构,可大幅增加与电解液界面接触面积,缩短离子扩散路径,促进离子迁移与电子转移。进一步利用该复合材料作为阳极,自制活性炭作为阴极,构建出一种新型钠离子电容器。研究证实,该钠离子电容器工作电压可达4.0 V,可输出140.75 Wh·kg^(-1)的最大能量密度和12.43 kW·kg^(-1)的最高功率密度。综上,该研究结果可为钠离子储能器件用高容量锑基阳极材料的优化设计提供可借鉴的思路。 展开更多
关键词 石墨烯 锑基阳极 电化学置换反应 二维复合材料 钠离子电容器
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The cytosolic isoform of triosephosphate isomerase,ZmTPI4,is required for kernel development and starch synthesis in maize(Zea mays L.)
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作者 Wenyu Li Han Wang +7 位作者 Qiuyue Xu Long zhang Yan Wang Yongbiao Yu Xiangkun Guo zhiwei zhang Yongbin Dong Yuling Li 《The Crop Journal》 SCIE CSCD 2024年第2期401-410,共10页
Triosephosphate isomerase(TPI)is an enzyme that functions in plant energy production,accumulation,and conversion.To understand its function in maize,we characterized a maize TPI mutant,zmtpi4.In comparison to the wild... Triosephosphate isomerase(TPI)is an enzyme that functions in plant energy production,accumulation,and conversion.To understand its function in maize,we characterized a maize TPI mutant,zmtpi4.In comparison to the wild type,zmtpi4 mutants showed altered ear development,reduced kernel weight and starch content,modified starch granule morphology,and altered amylose and amylopectin content.Protein,ATP,and pyruvate contents were reduced,indicating ZmTPI4 was involved in glycolysis.Although subcellular localization confirmed ZmTPI4 as a cytosolic rather than a plastid isoform of TPI,the zmtpi4 mutant showed reduced leaf size and chlorophyll content.Overexpression of ZmTPI4 in Arabidopsis led to enlarged leaves and increased seed weight,suggesting a positive regulatory role of ZmTPI4 in kernel weight and starch content.We conclude that ZmTPI4 functions in maize kernel development,starch synthesis,glycolysis,and photosynthesis. 展开更多
关键词 MAIZE Kernel STARCH Weight PHOTOSYNTHESIS
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Influence of Polyaluminum Chloride Residue on the Strength andMicrostructure of Cement-Based Materials
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作者 Ping Xu zhiwei zhang +2 位作者 Zhenguo Hou Mankui Zheng Jin Tong 《Fluid Dynamics & Materials Processing》 EI 2024年第6期1299-1312,共14页
In this paper,cement and dechlorinated Polyaluminum Chloride Residue(PACR)have been used to prepare a net slurry and mortar specimens.Two hydration activity indicators have been used to quantitatively analyze the dech... In this paper,cement and dechlorinated Polyaluminum Chloride Residue(PACR)have been used to prepare a net slurry and mortar specimens.Two hydration activity indicators have been used to quantitatively analyze the dechlorinated PACR hydration activity.In particular,the effect of dechlorinated PACR content on the compressive strength of mortar has been assessed by means of compressive strength tests.Moreover,X-ray diffraction(XRD)and scanning electron microscopy(SEM)have been employed to observe the microstructure of the considered hydration products.The following results have been obtained.The 28th day activity index of the dechlorinated PACR is 75%,and therefore it meets the criterion for the use of active admixture.The increase in the content of the dechlorinated PACR tends to reduce the compressive strength of mortar specimens,however,it is beneficial to its later strength growth.When the content is not greater than 10%,the strength remains unchanged,otherwise,it decreases.The PACR does not form a new crystalline phase in the cement slurry,and the dechlorinated PACR remains active until the age of the 28th day.The inclusion of the PACR mainly deteriorates the early strength of the cement slurry,but it promotes the production of hydration products in the cement slurry after the 7th day. 展开更多
关键词 Dechlorinated polyaluminum chloride residue activity index STRENGTH MICROSTRUCTURE hydration product
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Multi-Objective Optimization of Multi-Product Parallel Disassembly Line Balancing Problem Considering Multi-Skilled Workers Using a Discrete Chemical Reaction Optimization Algorithm
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作者 Xiwang Guo Liangbo Zhou +4 位作者 zhiwei zhang Liang Qi Jiacun Wang Shujin Qin Jinrui Cao 《Computers, Materials & Continua》 SCIE EI 2024年第9期4475-4496,共22页
This work investigates a multi-product parallel disassembly line balancing problem considering multi-skilled workers.A mathematical model for the parallel disassembly line is established to achieve maximized disassemb... This work investigates a multi-product parallel disassembly line balancing problem considering multi-skilled workers.A mathematical model for the parallel disassembly line is established to achieve maximized disassembly profit and minimized workstation cycle time.Based on a product’s AND/OR graph,matrices for task-skill,worker-skill,precedence relationships,and disassembly correlations are developed.A multi-objective discrete chemical reaction optimization algorithm is designed.To enhance solution diversity,improvements are made to four reactions:decomposition,synthesis,intermolecular ineffective collision,and wall invalid collision reaction,completing the evolution of molecular individuals.The established model and improved algorithm are applied to ball pen,flashlight,washing machine,and radio combinations,respectively.Introducing a Collaborative Resource Allocation(CRA)strategy based on a Decomposition-Based Multi-Objective Evolutionary Algorithm,the experimental results are compared with four classical algorithms:MOEA/D,MOEAD-CRA,Non-dominated Sorting Genetic Algorithm Ⅱ(NSGA-Ⅱ),and Non-dominated Sorting Genetic Algorithm Ⅲ(NSGA-Ⅲ).This validates the feasibility and superiority of the proposed algorithm in parallel disassembly production lines. 展开更多
关键词 Parallel disassembly line balancing problem MULTI-PRODUCT multiskilled workers discrete chemical reaction optimization algorithm
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How does network intermediary affect collaborative innovation?Evidence from Chinese listed companies
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作者 zhiwei zhang Wenhao Zhou 《Journal of Data and Information Science》 CSCD 2024年第4期49-70,共22页
Purpose:This study aims to explore how network intermediaries influence collaborative innovation performance within inter-organizational technological collaboration networks.Design/methodology/approach:This study empl... Purpose:This study aims to explore how network intermediaries influence collaborative innovation performance within inter-organizational technological collaboration networks.Design/methodology/approach:This study employs a mixed-method approach,combining quantitative social network analysis with regression techniques to investigate the role of network intermediaries in collaborative innovation performance.Using a patent dataset of Chinese industrial enterprises,the research constructs the collaboration networks and analyzes their structural positions,particularly focusing on their role as intermediaries,characterized by betweenness centrality.Negative binomial regression analysis is employed to assess how these network characteristics shape innovation outcomes.Findings:The study reveals that firms in intermediary positions enhance collaborative innovation performance,but this effect is nuanced.A key finding is that network clustering negatively moderates the intermediary-innovation relationship.Highly clustered networks,while fostering local collaboration,may limit the innovation potential of intermediaries.On the other hand,relationship strength,measured by collaboration intensity and trust among firms,positively moderates the intermediary-innovation link.Research limitations:This study has several limitations that present opportunities for further research.The reliance on quantitative social network analysis may overlook the complexity of intermediaries’roles,and future studies could benefit from incorporating qualitative methods to better understand cultural and institutional factors.Additionally,cross-country comparisons are needed to assess the consistency of these dynamics in different contexts.Practical implications:The study offers practical insights for firms and policymakers.Organizations should strategically position themselves as network intermediaries to access diverse information and resources,thereby improving innovation performance.Building strong trust helps using network intermediary advantages.For firms in highly clustered networks,it is important to seek external partners to avoid limiting their exposure to new ideas and technologies.This research emphasizes the need to balance network diversity with relationship strength for sustained innovation.Originality/value:This research contributes to the literature by offering new insights into the role of network intermediaries,presenting a comprehensive framework for understanding the interaction between network dynamics and firm innovation. 展开更多
关键词 Network intermediary Collaborative innovation Social network Relationship strength
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DNA Methylation Variation Is Identified in Monozygotic Twins Discordant for Congenital Heart Diseases
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作者 Shuliang Xia Huikang Tao +10 位作者 Shixin Su Xinxin Chen Li Ma Jianru Li Bei Gao Xumei Liu Lei Pi Jinqing Feng Fengxiang Li Jia Li zhiwei zhang 《Congenital Heart Disease》 SCIE 2024年第2期247-256,共10页
Aims:Multiple genes and environmental factors are known to be involved in congenital heart disease(CHD),but epigenetic variation has received little attention.Monozygotic(MZ)twins with CHD provide a unique model for e... Aims:Multiple genes and environmental factors are known to be involved in congenital heart disease(CHD),but epigenetic variation has received little attention.Monozygotic(MZ)twins with CHD provide a unique model for exploring this phenomenon.In order to investigate the potential role of Deoxyribonucleic Acid(DNA)methyla-tion in CHD pathogenesis,the present study examined DNA methylation variation in MZ twins discordant for CHD,especially ventricular septal defect(VSD).Methods and Results:Using genome-wide DNA methylation profiles,we identified 4004 differentially methylated regions(DMRs)in 18 MZ twin pairs discordant for CHD,and 2826 genes were identified.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis revealed a list of CHD-associated pathways.To further investigate the role of DNA methylation in VSD,data from 7 pairs of MZ twins with VSD were analyzed.We identified 1614 DMRs corresponding to 1443 genes associated with arrhythmogenic right ventricular cardiomyopathy,cyclic guanosine monopho-sphate-protein kinase G(cGMP-PKG)signaling pathway by KEGG analysis,and cell-cell adhesion,calcium ion transmembrane transport by GO analysis.A proportion of DMR-associated genes were involved in calcium signaling pathways.The methylation changes of calcium signaling genes might be related to VSD pathogenesis.Conclusion:CHD is associated with differential DNA methylation in MZ twins.CHD may be etiologically linked to DNA methylation,and methylation of calcium signaling genes may be involved in the development of VSD. 展开更多
关键词 Congenital heart disease monozygotic twins methylation modification EPIGENETICS
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CdTe半导体量子点的制备及其荧光性能测定
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作者 刘建军 杨雪 +5 位作者 张弛 赵雪钰 张志玮 陈咏梅 徐庆红 金劭 《大学化学》 CAS 2024年第7期307-315,共9页
半导体量子点是一种由Ⅱ–Ⅵ族(CdSe,CdTe,CdS,ZnTe,ZnO)、Ⅲ–Ⅴ族(InAs,GaSb,InP)和Ⅳ族(Si,Ge)元素组成的纳米颗粒。目前研究较多的主要是Ⅱ–Ⅵ族的CdS、CdSe、CdTe等半导体量子点,它们具有窄带隙而表现出优异的荧光特性,这些特性... 半导体量子点是一种由Ⅱ–Ⅵ族(CdSe,CdTe,CdS,ZnTe,ZnO)、Ⅲ–Ⅴ族(InAs,GaSb,InP)和Ⅳ族(Si,Ge)元素组成的纳米颗粒。目前研究较多的主要是Ⅱ–Ⅵ族的CdS、CdSe、CdTe等半导体量子点,它们具有窄带隙而表现出优异的荧光特性,这些特性是与其本征的量子尺寸效应密切相关的。本实验采用简便的水相回流法,以巯基乙酸作为保护剂,NaHTe为Te前体,在3 h的回流反应中制备出多种颜色的CdTe半导体量子点,并针对实验中出现的NaHTe转移液体过程中易被氧化的问题作出了改进,对产物的荧光性能进行了测定,最终得到了一系列量子产率达到48%的CdTe量子点。实验具有工艺简便、试剂消耗少、荧光变化明显的优点,对实验难点的改进使其具有良好的操作性与可重复性,适合拓展为本科生无机化学、仪器分析实验以及专业综合实验。 展开更多
关键词 半导体量子点 光致发光 荧光光谱分析法 荧光量子产率
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Effects of Microbial Fertilizers on Soil Improvement and Wheat Growth Characteristics in Saline-alkali Land
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作者 Gen SONG Ziru LI +12 位作者 Baohai zhang Zhenhua JIA Jirong CUI Dingxin GUO Lili HAN Yanhong WU Jianlong FENG Yan GAO Mingying LIU Chunguang SONG Guojia JI Changsong WANG zhiwei zhang 《Agricultural Biotechnology》 2024年第4期76-81,共6页
[Objectives]This study was conducted to further enrich the research on saline-alkali land improvement,and explore the effects of biological bacterial fertilizers containing Bacillus subtilis and Bacillus velezensis HM... [Objectives]This study was conducted to further enrich the research on saline-alkali land improvement,and explore the effects of biological bacterial fertilizers containing Bacillus subtilis and Bacillus velezensis HM-3 in saline-alkali land improvement and crop growth promotion.[Methods]Wheat was planted in saline-alkali land in Huanghua City,Hebei Province,and a mixed application experiment was carried out using biological agents from Hemiao Biotechnology Co.,Ltd.[Results]Compared with the field of control check(CK),water-soluble salts and pH value in the experimental fields decreased,and living bacteria count in the soil increased.Meanwhile,the economic characters of wheat in the experimental fields showed excellent performance,with yields increasing by 39.09%and 27.49%compared with the CK.It could be seen that the application of biological bacterial fertilizers achieved obvious effects of improving saline-alkali soil and increasing wheat yield.[Conclusions]In this study,the effects of biological bacterial fertilizers on saline-alkali land and wheat growth characters were clarified,providing some technical support and theoretical guidance for wheat planting in Huanghua saline-alkali land. 展开更多
关键词 Saline-alkali land Soil improvement WHEAT YIELD
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Analytical solution for longitudinal deformation of shield tunnel induced by overcrossing tunnelling considering circumferential joints
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作者 zhiwei zhang Rongzhu Liang +4 位作者 Zhongchao Li Cheng Kang MHEl Naggar Mingzhao Xiao Wenbing Wu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第9期2355-2374,共20页
This paper presents a new analytical solution for assessing the longitudinal deformation of shield tunnel associated with overcrossing tunnelling in consideration of circumferential joints.A simplified longitudinal be... This paper presents a new analytical solution for assessing the longitudinal deformation of shield tunnel associated with overcrossing tunnelling in consideration of circumferential joints.A simplified longitudinal beam-spring model(SLBSM)is established to model the longitudinal behaviours of shield tunnel,which can consider the opening and dislocation between segmental rings simultaneously.Then,the existing tunnel is treated as the SLBSM resting on the elastic foundation.The state equations including tunnel displacements and internal forces are constructed to solve the discontinuous deformation of circumferential joint-segmental ring.The feasibility of the proposed solution is verified through three well-documented cases.The predictions from the proposed method are also compared with other analytical methods.It is found that the proposed method can well capture the deformation of tunnel segmental rings and joints,where the rigid displacement mainly occurs in the segmental rings while the rotation and dislocation occur in the circumferential joints.Some dominant parameters are also analysed to explore the effects on existing tunnel deformation,including the rotation stiffness and shearing stiffness of joints,the skew angle and the clearance between new and old tunnels. 展开更多
关键词 Overcrossing tunnelling Shield tunnel Circumferential joints Longitudinal beam-spring model(LBSM) Opening DISLOCATION
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Intermediate and Long-Term Follow-Up of Transcatheter Closure of Congenital Coronary Cameral Fistulas in Infants and Children:Experience from a Single Center
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作者 Yifan Li Zewen Chen +2 位作者 Yumei Xie Shushui Wang zhiwei zhang 《Congenital Heart Disease》 SCIE 2023年第4期413-430,共18页
Background:Limited data are available regarding intermediate and long-term outcomes of transcatheter closure(TCC)of coronary cameral fistulas(CCFs)in the pediatric patients.Methods:All pediatric patients diagnosed wit... Background:Limited data are available regarding intermediate and long-term outcomes of transcatheter closure(TCC)of coronary cameral fistulas(CCFs)in the pediatric patients.Methods:All pediatric patients diagnosed with CCFs who were scheduled to undergo TCC between 2005 and 2019 were retrospectively enrolled in the study.Results:A total of 66 patients(median age:3.93 years,median weight:15 kg)underwent attempted TCC of CCFs.Immediate successful device implantation was achieved in 62 patients,and immediate complete occlusion was achieved in 44 patients(44/62%,71.0%).The closure procedure was waived in 2 patients due to anatomical factors.A total of 6 periprocedural complications occurred in 5 patients,including acute myocardial infarction(n=3),procedure-related death(n=1),device embolization(n=1),and rupture of tricuspid chordae tendineae(n=1).The acute procedural success rate was 89.4%(59/66),while the acute complication rate was 9.1%(6/66).Follow-up data were collected for 58(93.5%)out of 62 patients at a median of 9.3 years(range:3.0–15.7 years).10 adverse events occurred in 9 patients,including 5 follow-up complications(1 aortic valve perforation,1 coronary thrombosis,1 progressive aneurysmal dilation after reintervention,and 2 cases of new-onset tricuspid valve prolapse with significant regurgitation),and 5 closure failure with large residual shunts.The intermediate and long-term adverse event rate was 17.2%(10/58).The anatomical features associated with both acute and follow-up adverse events were large CCFs(p=0.005),and giant coronary artery aneurysms(CAAs)(p=0.029).Conclusions:TCC of CCFs in infants and children appears to be effective and is associated with a relatively low complication rate.Large CCFs and giant CAAs represent a higher risk of both acute and intermediate and long-term adverse events after closure. 展开更多
关键词 Coronary cameral fistulas transcatheter closure PEDIATRIC
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A Review on Metal-Organic Framework-Derived Porous Carbon-Based Novel Microwave Absorption Materials 被引量:25
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作者 zhiwei zhang Zhihao Cai +5 位作者 Ziyuan Wang Yaling Peng Lun Xia Suping Ma Zhanzhao Yin Yi Huang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第4期1-29,共29页
The development of microwave absorption materials(MAMs) is a considerable important topic because our living space is crowed with electromagnetic wave which threatens human’s health.And MAMs are also used in radar st... The development of microwave absorption materials(MAMs) is a considerable important topic because our living space is crowed with electromagnetic wave which threatens human’s health.And MAMs are also used in radar stealth for protecting the weapons from being detected.Many nanomaterials were studied as MAMs,but not all of them have the satisfactory performance.Recently,metal-organic frameworks(MOFs) have attracted tremendous attention owing to their tunable chemical structures,diverse properties,large specific surface area and uniform pore distribution.MOF can transform to porous carbon(PC) which is decorated with metal species at appropriate pyrolysis temperature.However,the loss mechanism of pure MOF-derived PC is often relatively simple.In order to further improve the MA performance,the MOFs coupled with other loss materials are a widely studied method.In this review,we summarize the theories of MA,the progress of different MOF-derived PC-based MAMs,tunable chemical structures incorporated with dielectric loss or magnetic loss materials.The different MA performance and mechanisms are discussed in detail.Finally,the shortcomings,challenges and perspectives of MOF-derived PC-based MAMs are also presented.We hope this review could provide a new insight to design and fabricate MOF-derived PC-based MAMs with better fundamental understanding and practical application. 展开更多
关键词 Metal-organic frameworks Porous carbon Microwave absorption material Reflection loss Effective absorption bandwidth
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Three dimensional velocity structure and accurate earthquake location in Changning–Gongxian area of southeast Sichuan 被引量:19
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作者 Feng Long zhiwei zhang +5 位作者 YuPing Qi MingJian Liang Xiang Ruan WeiWei Wu GuoMao Jiang LongQuan Zhou 《Earth and Planetary Physics》 CSCD 2020年第2期163-177,共15页
In order to understand the crustal structure and tectonic background of the Changning–Gongxiang area, southeastern Sichuan Province, where a series of moderate-to-strong earthquakes occurred in recent years, we utili... In order to understand the crustal structure and tectonic background of the Changning–Gongxiang area, southeastern Sichuan Province, where a series of moderate-to-strong earthquakes occurred in recent years, we utilized the seismic phase data both from a local dense array and from the regional seismic networks;we used the tomoDD program to invert for the high-resolution three-dimensional velocity structure within the depth range of 0–10 km and for accurate hypocentral locations in this area. We analyzed the seismogenic structures for the events of Xingwen M5.7 in 2018 and Gongxian M5.3 and Changning M6.0 in 2019. The results show that:(1) widespread lateral inhomogeneity exists in the velocity structure of the study area, and the location of the velocity anomaly is largely consistent with known structures. In the range of distinguishable depth, the inhomogeneity decreases with increasing depth, and the velocity structure anomalies in some areas are continuous in depth;(2) earthquakes occurred in clusters, showing the characteristics of zonal folding trends in the NW-SE and NE-SW directions;the focal depth in the area is generally shallow in both the sedimentary cap and the crystalline basement. The seismogenic structures of small earthquake clusters are different in size and occurrence in different sections, and the clusters occurred mostly in regions with high P-or S-wave velocities;(3) synthesis of a variety of data suggests that the seismogenic structures of the Xingwen M5.7 and Changning M6.0 earthquakes are associated with slip faults that trend NW-SE in, respectively, the south wing and the axis of the Changning–Shuanghe anticline, while that of the Gongxian M5.3 earthquake is associated with thrust faults that trend N-S in the Jianwu syncline region. The dynamic sources of the three earthquakes are all from the SE pushing of the Qinghai–Tibet block on the Sichuan basin;(4) the risk of future strong earthquakes in this area must be reevaluated in light of the facts(a)that in recent years, moderate-to-strong earthquake swarms have occurred frequently in southeast Sichuan;(b) that the complex structural area exhibits the easy-to-trigger characteristic, and(c) that the small-scale faults in this area are characterized by the phenomenon of stress "lock and release". 展开更多
关键词 southeastern Sichuan Sichuan Basin three-dimensional velocity structure earthquake precise location
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Spatio-temporal variation of the stress field in the Wenchuan aftershock region 被引量:3
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作者 Feng Long Guixi Yi +1 位作者 Xueze Wen zhiwei zhang 《Earthquake Science》 CSCD 2012年第5期517-526,共10页
Focal mechanism solutions and centroid depths of 312 M≥4 aftershocks from the 2008 Wenchuan earthquake sequence have been derived by CAP (Cut and Paste) method from broadband waveform data with relatively high sign... Focal mechanism solutions and centroid depths of 312 M≥4 aftershocks from the 2008 Wenchuan earthquake sequence have been derived by CAP (Cut and Paste) method from broadband waveform data with relatively high signal-to-noise ratio (SNR). Following this, we have analyzed the distribution of focal depths and the stress tensors, as well as the types of focal mechanisms. The major results are: (1) different cross-sections show that the depth ranges of the aftershocks at the southern and northern ends of the aftershock area along the Longmenshan fault zone are wider than those on the central segment, where rare M≥4 aftershocks occurred at depths shallower than 10 kin. The main faults trend to the NW on the southern and central segments, and for the northern segment, no dominant trend direction has been determined; (2) stress tensor distribution demonstrates that the majority of the aftershock areas on the cross-section along the major axis are mainly under compressive stress perpendicular to the profile; however, for the areas near Lixian, Beichuan, Qingchuan and the shallow parts of its northern segment, large principal stress components are parallel to the major axis profile direction. On the cross-sections perpendicular to the major axis, the three areas above can be divided into two parts: one with dominantly compressional stress near the major faults of the Longmenshan fault zone on the SE side, and the other with NE-direction push along the fault zone on the NW side; (3) the stress tensor distribution in map view is very similar to those on the vertical cross-sections. In map view, the orientation of the principal compressional stress axis $1 on the central segment of the aftershock area presents an SE-trending arc shape; (4) the stress tensor slices at different depths show that the orientation of S1 axis mainly changes on the central segment and at the northern end, indicating that the two segments have different seismogenic structures at different depths; (5) with the exception of the northern end of the aftershock region, the orientation of the $1 axis changes little during the early and late stages, illustrating the seismogenic structures are relatively stable; (6) preliminary analyses for the seismogenic structures at the northern end indicated that deeper strike-slip quakes occurred on the ENE-striking branch at first, and then the NNE-striking branch faults at the northern end were activated and generated a series of relatively shallow strike-slip earthquakes due to subsequent stress-triggering; (7) the aftershock triggering mechanism that occurred near Lixian is different between the shallow and deep depths, and between the early and late stages, indicating that the main faults and the branch faults responsible for aftershocks are at different depths. Consequently, the relaxation effect of the main shock particularIy impacts the branch faults. 展开更多
关键词 Wenchuan earthquake sequence focal depth focal mechanism solution stress tensor stress field
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The seismicity and tectonic stress field characteristics of the Longmenshan fault zone before the Wenchuan M_S8.0 earthquake 被引量:3
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作者 zhiwei zhang Wanzheng Cheng +1 位作者 Xiang Ruan Peng Wu 《Earthquake Science》 CSCD 2009年第2期119-128,共10页
The seismicity of Longrnenshan fault zone and its vicinities before the 12 May 2008 Wenchuan Ms8.0 earthquake is studied. Based on the digital seismic waveform data observed from regional seismic networks and mobile s... The seismicity of Longrnenshan fault zone and its vicinities before the 12 May 2008 Wenchuan Ms8.0 earthquake is studied. Based on the digital seismic waveform data observed from regional seismic networks and mobile stations, the focal mechanism solutions are determined. Our analysis results show that the seismicities of Longmenshan fault zone before the 12 May 2008 Wenchuan earthquake were in stable state. No obvious phenomena of seismic activity intensifying appeared. According to focal mechanism solutions of some small earthquakes before the 12 May 2008 Wenchuan earthquake, the direction of principal compressive stress P-axis is WNW-ESE. The two hypocenter fault planes are NE-striking and NW-striking. The plane of NE direction is among N50°-70°E, the dip angles of fault planes are 60°-70° and it is very steep. The faultings of most earthquakes are dominantly characterized by dip-slip reverse and small part of faultings present strike-slip. The azimuths of principal compressive stress, the strikes of source fault planes and the dislocation types calculated from some small earthquakes before the 12 May 2008 Wenchuan earthquake are in accordance with that of the main shock. The average stress field of micro-rupture along the Longmenshan fault zone before the great earthquake is also consistent with that calculated from main shock. Zipingpu dam is located in the east side 20 km from the initial rupture area of the 12 May 2008 Wenchuan earthquake. The activity increment of small earthquakes in the Zipingpu dam is in the period of water discharging. The source parameter results of the small earthquakes which occurred near the initial rupture area of the 12 May 2008 Wenchuan earthquake indicate that the focal depths are 5 to 14 km and the source parameters are identical with that of earthquake. 展开更多
关键词 Wenchuan earthquake Longmenshan fault zone focal mechanism solution tectonic stress field
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D-S Evidence Theory Based Trust Ant Colony Routing in WSN 被引量:3
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作者 Ziwen Sun zhiwei zhang +1 位作者 Cheng Xiao Gang Qu 《China Communications》 SCIE CSCD 2018年第3期27-41,共15页
This paper proposes a trust ant colony routing algorithm by introducing a node trust evaluation model based on the D-S evidence theory into the ant colony routing protocol to improve the security of wireless sensor ne... This paper proposes a trust ant colony routing algorithm by introducing a node trust evaluation model based on the D-S evidence theory into the ant colony routing protocol to improve the security of wireless sensor networks. To reduce the influence of conflict evidences caused by malicious nods, the consistent intensity is introduced to preprocess conflict evidences before using the D-S combination rule to improve the reliability of the D-S based trust evaluation. The nodes with high trust values will be selected as the routing nodes to insure the routing security, and the trust values are used as heuristic functions of the ant colony routing algorithm. The simulation tests are conducted by using the network simulator NS2 to observe the outcomes of performance metrics of packets loss rate and average end-to-end delay etc. to indirectly evaluate the security issue under the attack of inside malicious nodes. The simulation results show that the proposed trust routing algorithm can efficiently resist malicious attacks in terms of keeping performances of the average end-to-end delay, the throughtput and the routing packet overhead under attacking from malicious nodes. 展开更多
关键词 wireless sensor networks antcolony routing trust evaluation model D-Sevidence theory NS2 simulation
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Problems and Solutions about Land Use of Different Karst Environments in Southern China 被引量:2
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作者 zhiwei zhang zhangxiong ZHU Zhilin WEN 《Asian Agricultural Research》 2013年第10期51-55,60,共6页
This paper is aimed to analyze the current situation and problems about land use of various karst environments via field survey,documentation and comparison methods,and to make reasonable recommendations about land us... This paper is aimed to analyze the current situation and problems about land use of various karst environments via field survey,documentation and comparison methods,and to make reasonable recommendations about land use and management for different karst types in a bid to provide theoretical and practical basis for optimization of karst land use and the comprehensive control of karst rock desertification.The results show that,①as the bare karst areas are lack of water and soil and highly vulnerable to droughts and floods,land utilization in such areas should follow the principles of soil and water conservation and ecological restoration,emphasize both the ecological benefit and the economic benefits and reasonably configure the land resources to achieve virtuous circle;②in covered karst areas,the most important task is to take measures to prevent the appearance of secondary karst rock desertification,water exhaustion and karst collapse;③the buried karst areas shall mainly focus on prevention of overlaying sand shale collapse,and possible pollution of deep karst water and the surface land resulted from exploration and exploitation of oil and gas and geothermal water.④The final conclusion is that features and problems of land utilization of the three karst types are different from each other,and that the general principle for land use in karst regions shall be based on the local conditions. 展开更多
关键词 LAND use TYPES of KARST environments KARST ROCK de
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LaNiO3 as a Novel Anode for Lithium-Ion Batteries 被引量:1
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作者 Chang zhang Cong Wu +2 位作者 zhiwei zhang Yanran Shen Wei Liu 《Transactions of Tianjin University》 EI CAS 2020年第2期142-147,共6页
Lithium-ion batteries(LIBs) have been developed for over 30 years;however, existing electrode materials cannot satisfy the increasing requirements of high-energy density, stable cycling, and low cost. Here, we present... Lithium-ion batteries(LIBs) have been developed for over 30 years;however, existing electrode materials cannot satisfy the increasing requirements of high-energy density, stable cycling, and low cost. Here, we present a perovskite-type LaNiO3 oxide(LNO) as a new negative electrode material. LNO was successfully synthesized by a sol-gel method. The microstructure and electrochemical performance of LNO calcined at various temperatures have been systematically investigated. The LNO electrode shows a high rate capability and long cycling stability. In a C-rate test, a specific capacity of 77 mAh/g was exhibited at 6 C. LNO can also deliver a specific capacity of 92 mAh/g after 200 cycles at 1 C. This paper presents a type of binary metal oxide as a new anode material for high-performance LIBs. 展开更多
关键词 LITHIUM-ION batteries LaNiO 3 Sol–gel method Perovskite Electrochemical properties
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Effect of super-high pressure on microstructure and mechanical properties of Mg_(97)Zn_(1)Y_(2) alloys 被引量:1
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作者 Hui Fu Na Liu +1 位作者 zhiwei zhang Qiuming Peng 《Journal of Magnesium and Alloys》 SCIE EI CAS 2016年第4期302-305,共4页
Super-high pressure(SHP)technique plays an increasing role in the fields of materials science and engineering.Herein,the Mg_(97)Zn_(1)Y_(2) alloy was heat-treated under SHP(6 GPa)by cubic-anvil large-volume press with... Super-high pressure(SHP)technique plays an increasing role in the fields of materials science and engineering.Herein,the Mg_(97)Zn_(1)Y_(2) alloy was heat-treated under SHP(6 GPa)by cubic-anvil large-volume press with six rams for 2 h in the temperature range of 500–1200℃.The microstructure and mechanical properties were investigated.The results indicated that the as-cast sample consists of α-Mg equiaxed dendrites and continuous lamellar long period stacking ordered(LPSO)phase in grain boundaries.After the SHP treatment,the LPSO phase is gradually replaced by eutectic phase(Mg,Zn)_(3)Y with increasing temperature.The microhardness and strength of sample prepared at 1100℃ under SHP treatment are significantly improved compared with the as-cast one at room temperature.The improved mechanical behaviors are mainly attributed to LPSO phase kink-banding strengthening at low temperature and the precipitation strengthening of a large amount of fine(Mg,Zn)_(3)Y particles at high temperature after SHP treatment.It reveals the SHP is an effective approach to prepare high performance Mg alloys. 展开更多
关键词 Super-high pressure Microstructure Mechanical properties Mg_(9)7Zn_(1)Y_(2)alloy
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Design of Wireless Power Transfer with High Efficiency for Biomedical Implants 被引量:1
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作者 Qingya Li zhiwei zhang Jingna Mao 《Journal of Beijing Institute of Technology》 EI CAS 2022年第1期53-60,共8页
Wireless power transfer(WPT)technology is a popular choice for biomedical implant devices.The demands of higher efficiency and smaller implantation size are hard to compromise in previous studies.In the present work,a... Wireless power transfer(WPT)technology is a popular choice for biomedical implant devices.The demands of higher efficiency and smaller implantation size are hard to compromise in previous studies.In the present work,an implantable magnetic coupling resonant WPT system in-tegrated with a metasurface element working at 430 MHz is presented.Similar planar copper coil components for the transmitting and receiving structures are used to construct the primary system,and then the metasurface element is integrated to constitute the whole WPT system.The effects of the distances between the transmitting coil and skin surface,between the skin surface,and receiv-ing coil are discussed.The results show that the efficiency will be enhanced by 38-50 dB integrat-ing with the metasurface. 展开更多
关键词 wireless power transfer(WPT) MINIATURIZATION metasurface
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关于打造我省旅游主题服务区的探讨 被引量:1
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作者 韩一德 马丽娜 +1 位作者 张志伟 韩若峰 《青海交通科技》 2018年第4期5-7,共3页
本文在梳理国内"交通+旅游"最新政策及发展现状的基础上,结合我省省情及得天独厚的旅游资源优势,提出我省打造旅游主题服务区的建设思路。从社会效益和经济效益的角度出发,分析了我省建设旅游主题服务区的潜在价值,打造"... 本文在梳理国内"交通+旅游"最新政策及发展现状的基础上,结合我省省情及得天独厚的旅游资源优势,提出我省打造旅游主题服务区的建设思路。从社会效益和经济效益的角度出发,分析了我省建设旅游主题服务区的潜在价值,打造"交通+旅游"融合互联,合作共赢的新局面。 展开更多
关键词 交通+旅游 服务区 建设思路 潜在价值
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