检索结果-南通市图书馆

出行特征视角下社区老年人日间照料中心配置研究

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

城乡规划 2024年第1期 1-13页

作者：李云胡慧敏刘毓锦张东升范雅婷深圳大学建筑与城市规划学院城市规划系深圳市建筑环境优化设计研究重点实验室深圳大学建筑与城市规划学院深圳市坪山规划和自然资源研究中心安徽省城乡规划设计研究院有限公司

社区养老设施是支持老年人实现“在地化养老”的重要环节,在未来的城市建设中将大量配置。文章聚焦社区老年人日间照料设施,以深圳市为例,通过走访调研,收集老年人使用设施的出行数据,并基于设施供需匹配水平及布局公平性,综合评价设施... 详细信息

社区养老设施是支持老年人实现“在地化养老”的重要环节,在未来的城市建设中将大量配置。文章聚焦社区老年人日间照料设施,以深圳市为例,通过走访调研,收集老年人使用设施的出行数据,并基于设施供需匹配水平及布局公平性,综合评价设施配置的现状。研究发现:第一,老年人日间照料设施配置落后于老年人口增长,且存在设施运营不佳等现实问题;第二,老年人使用社区日间照料设施出行,可接受的最大范围远大于设施的服务半径;第三,综合分析设施供需匹配情况及布局公平性评价,认为目前社区老年人日间照料设施配置处于供给不足且分配不均阶段。文章结合老年人使用设施的出行特征、设施供应能力与空间服务水平评价,从设施分级体系构建、设施15分钟生活圈配置优化和设施功能空间耦合三方面,提出促进设施配置优化的建议。

关键词：社区日间照料设施出行特征配置水平供需匹配社会公平

Study of the Ballistic Impact Behavior of Protective Multi-Layer Composite Armor

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第7期140卷 171-199页

作者： dongsheng Jia Yingjie Xu Liangdi Wang Jihong Zhu Weihong zhang State IJR Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical UniversityXi’an710072China

The abalone shell,a composite material whose cross-section is composed of inorganic and organic layers,has high strength and *** by the abalone shell,several multi-layer composite plates with different layer sequences and thicknesses are studied as bullet-proof material in this *** investigate the ballistic performance of this multi-layer structure,the complete characterization model and related material parameters of large deformation,failure and fracture ofAl_(2)O_(3)ceramics andCarbon Fiber Reinforced Polymer(CFRP)are ***,3D finite element models of the proposed composite plates with different layer sequences and thicknesses impacted by a 12.7 mm armor-piercing incendiary(API)are built using Abaqus to predict *** simulation results show that the CFRP/Al2O3 ceramic/Ultrahigh Molecular Weight Polyethylene(UHMWPE)/CFRP(1 mm/4 mm/4 mm/1 mm)composite is the optimized stack of *** simulation results under specified layer sequence and thickness have a reasonable correlation with the experimental results and reflect the failure and fracture of the multi-layer composite protective armor.

关键词： Protective armor composite bionic design structure design mechanical property

Determination of elastic and plastic mechanical properties of dentin based on experimental and numerical studies

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2015年第10期36卷 1347-1358页

作者： Xingguo LI Bingbing AN dongsheng zhang Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Department of Mechanics Shanghai University Shanghai Key Laboratory of Mechanics in Energy Engineering

The aim of this study is to investigate the change of mechanical properties of human dentin due to aging and spatial variation. Sections of coronal dentin are made from human molars in three groups： young, mid-aged, and old patients. A nanoindentation test is conducted from regions near the pulp to the dentin-enamel junction （DE J） to evaluate the load-depth indentation response and determine Young＇s modulus and hardness. Based on the loading and unloading load-displacement curves in nanoindentation, a numerical model of plastic damage is used to study the plastic and the damage behaviors and the contribution to the degradation in the unloading stiffness. The experimental results show that Young＇s modulus of the inner dentin is significantly lower than that of outer dentin in each age group. Compared with the young dentin, the old dentin has greater hardness and Young＇s modulus with similar spatial variations. The magnitudes of the yield strength and the damage variable are also affected by aging and vary with spatial locations. In the same age group, the yield strength in inner dentin is lower than those in middle and outer dentin, more damage occurs with similar spatial variations, and the yield strength of young dentin is generally lower and causes more damage compared with those in both the mid-aged and old groups.

关键词： dentin mechanical property nanoindentation numerical simulation

Characteristics and genesis of tuffaceous shale oil lithofacies:A case study of Lucaogou Formation in Santanghu Basin

在线全文

学校读者我要写书评

暂无评论

Petroleum Research 2024年第1期9卷 37-47页

作者： dongsheng Xiao Xiong fei Xu Jilun Kang Yiting zhang PetroChina Tuha Oilfield Company Exploration and Development Research Institute China

Lucaogou Formation in the Santanghu Basin is a special lacustrine fine-grained sedimentary deposits rich in volcanic debris and carbonate,with abundant shale oil ***,understanding of shale oil characteristics and genesis remains ***,sedimentary environment,and formation mechanisms of tuffaceous shale oil are investigated based on core and thin section observations,X-ray diffraction,field emission SEM and geochemical *** show that three mixed lithofacies types are developed in Lucaogou Formation:blocky tuff,laminated tuffaceous dolomite,and laminated dolomitic *** lithofacies types are characterized by high content of felsic and dolostone,widespread organic matter,and low clay *** of tuffaceous shale oil sweet spots is primarily influenced by four factors:inputting of volcanic ash as a high-quality source rocks and reservoirs provides good material basis;devitrification of volcanic glass,calcitization,and dissolution are crucial for formation of reservoirs;expulsion of source rocks with high-abundance organic matter expulsion facilitates migration and accumulation of hydrocarbon in adjacent reservoirs;fracture development improves reservoir permeability to form highly productive sweet *** analyzing characteristics and genesis of tuffaceous shale oil,the main controlling factors of reservoir physical property and oil saturation are clarified,which is of great significance for selection of shale oil exploration zones.

关键词： shale oil Tuffaceous Formation mechanism Lucaogou formation Santanghu basin

Mechanical analysis of C/C composite grids in ion optical system

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2019年第11期40卷 1589-1600页

作者： Shuiqiang zhang Aijun LI Yuqin ZHENG dongsheng zhang School of Engineering Huzhou UniversityHuzhou 313000Zhejiang ProvinceChina Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072China Research Center for Composite Materials Shanghai UniversityShanghai 200444China Department of Mechanics Shanghai UniversityShanghai 200444China

The ion thruster is an engine with high specific impulse for satellites and spacecrafts,which uses electric energy to boost the *** ion optical system,also known as gate assemblies which consist of acceleration and screen grids,is the key component of the ion *** this paper,the static mechanical properties of the C/C composite grids are evaluated based on the structural *** volume element (RVE) is adopted to simplify the braded composite structure as a continuum *** dynamical behavior of the 100 mm ion thruster optics in the launch environment (1000g shock-load) is numerically modeled and simulated with the half-sine pulse *** impact response of the C/C and molybdenum gate assemblies on the stress distribution and deformation is *** simulated results indicate that the magnitudes of the normal displacement of the composite grids subject to the uniformly distributed load are on the same level as molybdenum grids although the normal stiffness of the composite grids is much *** subject to impact loading,the stress distribution in the C/C composite grids is similar to molybdenum grids while the stress magnitude is much *** finding shows that the C/C gate assemblies outperform molybdenum grids and meet the requirement of long lifetime service in space travel.

关键词： ion optical system C/C composite grid mechanical analysis

A new tunable elastic metamaterial structure for manipulating band gaps/wave propagation

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2021年第11期42卷 1543-1554页

作者： Zhenyu WANG Zhaoyang MA Xingming GUO dongsheng zhang Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai UniversityShanghai 200444China

A one-dimensional mechanical lattice system with local resonators is proposed as an elastic metamaterial model,which shows negative mass and negative modulus under specific frequency *** proposed representative units,consisting of accurately arranged rigid components,can generate controllable translational resonance and achieve negative mass and negative modulus by adjusting the local structural parameters.A shape memory polymer is adopted as a spring component,whose Young’s modulus is obviously affected by temperature,and the proposed metamaterials’tunable ability is achieved by adjusting *** effect of the shape memory polymer’s stiffness variation on the band gaps is investigated detailedly,and the special phenomenon of intersecting dispersion curves is discussed,which can be designed and controlled by adjusting *** dispersion relationship of the continuum metamaterial model affected by temperature is obtained,which shows great tunable ability to manipulate wave propagation.

关键词： tunable elastic metamaterial negative mass negative modulus

Cation-doped LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode with high rate performance

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 139-148页

作者： Long zhang dongsheng Yang Lilei Miao Chunmeng zhang Jiexiang Li Jiawei Wen Chunxia Wang Tiantian Cao Guoyong Huang Shengming Xu College of New Energy and Materials China University of PetroleumBeijing 102249China State Key Laboratory of Heavy Oil Processing College of Chemical EngineeringChina University of PetroleumBeijing 102249China Beijing Spacecrafts Beijing 100094China SINOPEC Sales Co. Ltd.Beijing 100728China SINOPEC Research Institute of Petroleum Processing Co. LtdBeijing 100083China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Beijing Key Laboratary of Fine Ceramics Tsinghua UniversityBeijing 100084China

The nickel-rich layered cathode material LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)has high energy density,lower cost and is a promising cathode material currently under ***,its electrochemical and structural stability is poor during *** the many modification methods,cation doping has been consistently proven to be an effective strategy for enhancing electrochemical ***,the NCM811 cathode material was modified by solid-phase reactions with Mg and Al *** addition,the corresponding mechanism of NCM811 cathode material-doped modification is explored by density functional theory(DFT)calculations,and we have extended this approach to other ternary cathode materials with different ratios and obtained universal *** with DFT calculations,the results show that Mg2+occupies the Li+site and reduces the degree of Li^(+)/Ni^(2+) mixture;Al^(3+) acts as a structural support during charging and discharging to prevent structural *** electrochemical properties were tested by an electrochemical workstation and the LAND system,and the results showed that the capacity retention rate increased to varying degrees from 63.66%to 69.87%and 89.05%for NCM811-Mg and NCM811-Al at room temperature after 300 cycles,*** study provides a theoretical basis and design strategy for commercializing cationic-doped modification of nickel-rich cathode materials.

关键词： Li-ion batteries Cathode materials Doped Electrochemical properties DFT calculation

An origami shield with supporting frame structures optimized by a feature-driven topology optimization method

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 447-456页

作者： dongsheng Jia Pengcheng Feng Liangdi Wang Longcan Chen Jun Wang Jihong Zhu Yingjie Xu Weihong zhang State IJR Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical UniversityXi'an710072China

In this paper,the design,manufacture and testing of an origami protective shield with a supporting frame structure are *** consists of an origami shield surface and a deployable supporting frame structure that needs to be portable and sufficiently ***,for the design of the shield surface,a threestage origami crease pattern is developed to reduce the shield size in the folded *** shield surface consists of several stiff modular panels and layered with flexible *** modular panels are made of a multi-layer composite where a ceramic layer is made of small pieces to improve durability as those small pieces enable restriction of crack ***,the supporting frame structure is designed as a chain-of-bars structure in order to fold into a highly compact state as a bundle of bars and deploy in ***,a feature-driven topology structural optimization method preserving component sequence is developed where the inter-dependence of sub-structures is taken into account.A bar with semi-circular ends is used as a basic design *** positions of the bar’s end points are treated as design variables and the width of the bars is kept ***,a constraint on the total length of the chain of bars is ***,the modular panels made of multi-layer composite and the full-scale prototype of the origami shield are fabricated and tested to verify the bullet-proof performance.

关键词： Origami Deployable structure Structure design Shield Composite materials

Different vertical distribution of zooplankton community between North Pacific Subtropical Gyre and Western Pacific Warm Pool: its implication to carbon flux

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2019年第6期38卷 32-45页

作者： Dong Sun dongsheng zhang Ruiyan zhang Chunsheng Wang Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic AdministrationHangzhou 310012China Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China

The mesozooplankton in both epipelagic and mesopelagic zones is essentially important for the study of ecosystem and biological carbon pump. Previous studies showed that the diel vertical migration (DVM) pattern of mesozooplankton varied among ecosystems. However, that pattern was largely unknown in the Western Pacific Warm Pool (WPWP). The vertical distribution, DVM and community structure of mesozooplankton from the surface to 1 000 m were compared at Stas JL7K (WPWP) and MA (North Pacific Subtropical Gyre, NPSG). Two sites showed similarly low biomass in both epipelagic and mesopelagic zones, which were in accordance with oligotrophic conditions of these two ecosystems. Stronger DVM (night/day ratio) was found at JL7K (1.31) than that at MA (1.09) on surface 0–100 m, and an obvious night increase of mesopelagic biomass was observed at JL7K, which was probably due to migrators from bathypelagic zone. Active carbon flux by DVM of zooplankton was estimated to be 0.23 mmol/(m2·d) at JL7K and 0.16 mmol/(m2·d) at MA. The community structure analysis showed that calanoid copepods, cnidarians and appendicularians were the main contributors to DVM of mesozooplankton at both sites. We also compared the present result with previous studies of the two ecosystems, and suggested that the DVM of mesozooplankton was more homogeneous within the WPWP and more variable within the NPSG, though both ecosystems showed typically extremely oligotrophic conditions. The different diel vertical migration strength of mesozooplankton between NPSG and WPWP implied different efficiency of carbon pump in these two ecosystems.

关键词： mesopelagic zone diel vertical migration biological pump vertical distribution active carbon flux