检索结果-南通市图书馆

Impact failure models and application condition of trees in debris-flow hazard mitigation

Journal of Mountain Science 2021年第7期18卷 1874-1885页

作者： JIN Ke CHEN Jian-gang CHEN Xiao-qing ZHAO Wan-yu si guang-wu GONG Xing-long Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China China-Pakistan Joint Research Center on Earth Sciences CAS-HECIslamabad 45320Pakistan University of Chinese Academy Sciences Beijing 100049China

Forestry has played an important role in hazard mitigation associated with debris *** forest mitigation measures refer to the experience of soil and water conservation,which disregard the destructive effect of debris flows,causing potentially serious *** of the effect of a forest on reducing debris-flow velocity and even stopping debris flows requires distinguishing between when the debris flow will destroy the forest and when the trees will withstand the debris-flow impact *** this paper,we summarized two impact failure models of a single tree: stem breakage and *** influences of different tree sizes characteristics(stem base diameter,tree weight,and root failure radius) and debris-flow characteristics(density,velocity,flow depth,and boulder diameter) on tree failure were *** observations obtained from the model adopted in this study show that trees are more prone to stem breakage than *** an increase in tree size,the ability to resist stem breakage and overturning ***-flow density influences the critical failure conditions of trees substantially less than the debrisflow velocity,depth,and boulder *** application conditions of forests in debris-flow hazard mitigation were proposed based on the analysis of the model *** proposed models were applied in the Xiajijiehaizi Gully as a case study,and the results explain the destruction of trees in the forest dispersing *** work provides references for implementing forest measures for debris-flow hazard mitigation.

关键词： Trees Impact failure model Forest application condition Debris flow mitigation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Failure criteria of unreinforced masonry walls of rural buildings under the impact of flash floods in mountainous regions

引用

Journal of Mountain Science 2022年第12期19卷 3388-3406页

作者： si guang-wu CHEN Xiao-qing CHEN Jian-gang ZHAO Wan-yu LI Shuai LI Xiang-ning Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041China China-Pakistan Joint Research Center on Earth Sciences CAS-HECIslamabad45320Pakistan University of Chinese Academy Sciences Beijing100049China

Damage to rural buildings in mountainous regions caused by flash floods accounts for a significant proportion of economic losses from *** unreinforced masonry(URM)wall is the most vulnerable structural element of rural buildings exposed to flash *** failure of a URM wall indicates damage to rural buildings in flash *** on the yield line theory of out-of-plane damage of URM walls and the virtual work method,brittle failure criteria for URM walls under the impact of flash floods were *** to the field investigation data of the 26 June 2020 flash flood event in Damawu Gully and the corresponding simulation results of FLO-2D,the disaster-causing process was analysed,and the failure criteria were *** building parameters were identified to influence the flood-resistance of URM walls,including the mortar grade,the span-to-height ratio of the wall,and the number of floors of the rural *** results showed that the cause of the 26June disaster was the diversion of a 50-year flash flood into the residential community on the alluvial *** affected buildings were constructed with hollow blocks and lacked flood-resistance *** critical failure depth of a URM wall restrained at the top by ring beams(RBs)under hydrostatic load conditions is 1.17 to 1.20 times greater than that of a URM wall without RBs,and the difference is even more pronounced when lowerstrength mortar is *** flood-resistance of a URM wall constructed with Mb 7.5 mortar and restrained by RBs is almost as strong as that of a URM wall constructed with Mb 20 mortar and without *** span-to-height ratio of a URM wall should not be greater than 1.875 in this ***,the flood-resistance of a URM wall with RB restraint is almost independent of the span-to-height *** brittle fracture energy of masonry mortar is more crucial to the flood-resistance of 4-edge restrained URM walls if L/Z>*** flood-resistance of the URM wa

关键词： Flash flood Rural buildings Unreinforced masonry wall Failure criteria Flood-resistance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unraveling brain aging through the lens of oral microbiota

引用

Neural Regeneration Research 2025年第7期20卷 1930-1943页

作者： Qinchao Hu si Wang Weiqi Zhang Jing Qu guang-Hui Liu State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijingChina Hospital of Stomatology Guanghua School of StomatologyGuangdong Provincial Key Laboratory of StomatologySun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Advanced Innovation Center for Human Brain Protection and National Clinical Research Center for Geriatric Disorders Xuanwu HospitalCapital Medical UniversityBeijingChina Aging Translational Medicine Center International Center for Aging and CancerBeijing Municipal Geriatric Medical Research CenterXuanwu HospitalCapital Medical UniversityBeijingChina CAS Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijingChina University of Chinese Academy of Sciences BeijingChina Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijingChina Aging Biomarker Consortium BeijingChina State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijingChina Beijing Institute for Stem Cell and Regenerative Medicine BeijingChina

The oral cavity is a complex physiological community encompassing a wide range of *** of oral microbiota can lead to various oral infectious diseases,such as periodontitis and tooth decay,and even affect systemic health,including brain aging and neurodegenerative *** studies have highlighted how oral microbes might be involved in brain aging and neurodegeneration,indicating potential avenues for intervention *** this review,we summarize clinical evidence demonstrating a link between oral microbes/oral infectious diseases and brain aging/neurodegenerative diseases,and dissect potential mechanisms by which oral microbes contribute to brain aging and *** also highlight advances in therapeutic development grounded in the realm of oral microbes,with the goal of advancing brain health and promoting healthy aging.

关键词： Alzheimer's disease brain aging multiple sclerosis neurodegeneration neurodegenerative diseases oral microbiota Parkinson's disease periodontitis bacteria Porphyromonas gingivalis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于禁忌搜索算法的机械优化设计

引用

煤矿机械 2018年第5期39卷 169-170页

作者：陈庆莹安斯光吴秀山中国计量大学机电工程学院杭州310018

为寻求更优更高效现代机械优化设计,结合禁忌搜索算法和遗传算法提出一种新的智能优化方法。为提高算法的全局寻优能力和减少寻优计算的时间,混合算法在结构上进行改进。给出的典型数学函数验证了算法的快速性和有效性,将其用于带式输... 详细信息

为寻求更优更高效现代机械优化设计,结合禁忌搜索算法和遗传算法提出一种新的智能优化方法。为提高算法的全局寻优能力和减少寻优计算的时间,混合算法在结构上进行改进。给出的典型数学函数验证了算法的快速性和有效性,将其用于带式输送机蜗杆减速器上的蜗轮齿圈体积优化的机械设计。优化结果与常规设计相比,优化效果较明显。

关键词：机械设计禁忌搜索算法(TS) 遗传算法(GA) 蜗轮齿圈

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic Regulation of Hydrogen Bonding Networks and Solvation Structures for Synergistic Solar‑Thermal Desalination of Seawater and Catalytic Degradation of Organic Pollutants

引用

Nano-Micro Letters 2025年第2期17卷 548-565页

作者： Ming‑Yuan Yu Jing wu guang Yin Fan‑Zhen Jiao Zhong‑Zhen Yu Jin Qu Beijing Key Laboratory of Advanced Functional Polymer Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China State Key Laboratory of Organic‑Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China

Although solar steam generation strategy is efficient in desalinating seawater,it is still challenging to achieve continuous solar-thermal desalination of seawater and catalytic degradation of organic ***,dynamic regulations of hydrogen bonding networks and solvation structures are realized by designing an asymmetric bilayer membrane consisting of a bacterial cellulose/carbon nanotube/Co_(2)(OH)_(2)CO_(3)nanorod top layer and a bacterial cellulose/Co_(2)(OH)_(2)CO_(3)nanorod(BCH)bottom ***,the hydrogen bonding networks inside the membrane can be tuned by the rich surface–OH groups of the bacterial cellulose and Co_(2)(OH)_(2)CO_(3)as well as the ions and radicals in situ generated during the catalysis ***,both SO_(4)^(2−)and HSO_(5)−can regulate the solvation structure of Na^(+)and be adsorbed more preferentially on the evaporation surface than Cl^(−),thus hindering the de-solvation of the solvated Na^(+)and subsequent nucleation/growth of ***,the heat generated by the solar-thermal energy conversion can accelerate the reaction kinetics and enhance the catalytic degradation *** work provides a flow-bed water purification system with an asymmetric solar-thermal and catalytic membrane for synergistic solar thermal desalination of seawater/brine and catalytic degradation of organic pollutants.

关键词： Solar steam generation Seawater desalination Catalytic degradation Bacterial cellulose Cobalt hydroxycarbonate nanorods

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

增湿条件下膨胀土边坡稳定性影响因素有限元分析

引用

铁道标准设计 2018年第10期62卷 31-36页

作者：张硕蒋良潍罗强李傲赢司光武高速铁路线路工程教育部重点实验室成都610031 西南交通大学土木工程学院成都610031

为研究雨季土体增重、强度降低及膨胀作用这三项影响膨胀土边坡稳定性作用因素的主次关系,基于热膨胀比拟增湿膨胀原理,考虑水平、竖向间的差异膨胀性,推导土体增湿膨胀的应力-应变方程,利用无荷膨胀率试验有限元模型进行参数验证;针对... 详细信息

为研究雨季土体增重、强度降低及膨胀作用这三项影响膨胀土边坡稳定性作用因素的主次关系,基于热膨胀比拟增湿膨胀原理,考虑水平、竖向间的差异膨胀性,推导土体增湿膨胀的应力-应变方程,利用无荷膨胀率试验有限元模型进行参数验证;针对某铁路膨胀土边坡,建立ABAQUS有限元强度折减模型,采用正交试验极差分析法,研究含水率变化条件下边坡稳定性影响因素的作用效应及敏感性。研究表明:当初始含水率较低时,土体强度降低对边坡稳定性的影响最为显著,膨胀作用次之,土体增重影响相对较小,随土体初始含水率增大,膨胀作用、土体增重的影响减弱;土体初始含水率较低时,考虑土体水平、竖向间差异膨胀性计算得到的稳定安全系数较传统的各向同性膨胀假设结果低0.11~0.13,随含水率的升高,差异膨胀性的影响减小。

关键词：膨胀土边坡增湿稳定性有限元强度折减法正交试验

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Prediction of the Charpy V-notch impact energy of low carbon steel using a shallow neural network and deep learning

引用

International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1309-1320页

作者： si-wei wu Jian Yang guang-ming Cao State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

The impact energy prediction model of low carbon steel was investigated based on industrial data. A three-layer neural network, extreme learning machine, and deep neural network were compared with different activation functions, structure parameters, and training functions. Bayesian optimization was used to determine the optimal hyper-parameters of the deep neural network. The model with the best performance was applied to investigate the importance of process parameter variables on the impact energy of low carbon steel. The results show that the deep neural network obtains better prediction results than those of a shallow neural network because of the multiple hidden layers improving the learning ability of the model. Among the models, the Bayesian optimization deep neural network achieves the highest correlation coefficient of 0.9536, the lowest mean absolute relative error of 0.0843, and the lowest root mean square error of 17.34 J for predicting the impact energy of low carbon steel. Among the variables, the main factors affecting the impact energy of low carbon steel with a final thickness of7.5 mm are the thickness of the original slab, the thickness of intermediate slab, and the rough rolling exit temperature from the specific hot rolling production line.

关键词： prediction shallow neural network deep neural network impact energy low carbon steel

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

山洪对村镇建筑破坏方式与建筑防洪加固技术研究现状

引用

科学技术与工程 2021年第23期21卷 9671-9681页

作者：司光武陈剑刚陈晓清赵万玉崔文榕中国科学院山地灾害与地表过程重点实验室中国科学院、水利部成都山地灾害与环境研究所成都610041 中国科学院大学北京100049 中国科学院青藏高原地球科学卓越创新中心北京100101

村镇建筑是当地居民最大不动产之一和山洪灾害中的主要承灾体。通过典型山洪事件灾后调查,将山洪对村镇建筑的破坏方式总结为:对建筑迎流面的冲击和顺流面的磨蚀、地基侵蚀、淤埋和浸泡5种类型。除了山洪作用强度,建筑的破坏程度还与自... 详细信息

村镇建筑是当地居民最大不动产之一和山洪灾害中的主要承灾体。通过典型山洪事件灾后调查,将山洪对村镇建筑的破坏方式总结为:对建筑迎流面的冲击和顺流面的磨蚀、地基侵蚀、淤埋和浸泡5种类型。除了山洪作用强度,建筑的破坏程度还与自身因素相关。现有的建筑抗洪加固技术包括:抬高建筑标高、设置钢管混凝土防撞桩、格宾石笼及挡墙、采取干式和湿式防洪策略、围墙合理开洞、优化建筑及房间布局。现有抗洪加固技术都只是对常规山洪防治措施的补充。今后需要加强对单体建筑破坏机理、建筑群遮掩效应作用规律和工程-生态协同减灾措施应用的研究。研究结果可为村镇建筑抗洪加固、山洪灾害防治和山区村镇绿色发展提供一定参考。

关键词：山洪村镇建筑防洪加固工程-生态措施

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

智慧医疗情境下四方主体隐私行为的交互机理及演化趋势研究

引用

现代情报 2025年第1期45卷 135-149页

作者：朱光吴晗逸刘雯南京信息工程大学风险治理与应急决策研究院江苏南京210044 南京信息工程大学管理工程学院江苏南京210044

[目的/意义]本文针对智慧医疗情境下隐私行为研究在博弈主体、模型参数等方面的不足,探寻患者、医疗机构、智慧医疗平台和政府四方主体之间的隐私行为交互机理与演化趋势。[方法/过程]基于演化博弈理论,构建患者、医疗机构、智慧医疗平... 详细信息

[目的/意义]本文针对智慧医疗情境下隐私行为研究在博弈主体、模型参数等方面的不足,探寻患者、医疗机构、智慧医疗平台和政府四方主体之间的隐私行为交互机理与演化趋势。[方法/过程]基于演化博弈理论,构建患者、医疗机构、智慧医疗平台和政府四方博弈模型。根据不同参数调节下各方行为策略的收益、成本、损失等计算收益矩阵,求解主体的演化稳定策略,并考虑不同因素对主体行为策略及系统稳定状态的影响。[结果/结论]患者的隐私披露行为与披露隐私后获得的服务收益密切相关,医疗机构的隐私保护投入成本和隐私泄露概率对其隐私保护行为有显著影响,智慧医疗平台的政府奖惩、罚款收益和投入成本是影响其严格管理行为的关键因素,政府的监管行为与奖惩机制等因素密切相关。通过应用本文模型和方法,可以动态调整隐私保护机制,明确各方职责,推动智慧医疗可持续健康发展。

关键词：智慧医疗演化博弈隐私行为患者医疗机构智慧医疗平台政府

来源：

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

Molecular simulation study of the microstructures and properties of pyridinium ionic liquid[HPy][BF_(4)]mixed with acetonitrile

引用

原子与分子物理学报 2025年第4期42卷 27-32页

作者： XU Jian-Qiang MA Zhao-Peng CHENG si LIU Zhi-Cong ZHU guang-Lai Department of Physics School of Physics and Electronic InformationAnhui Normal UniversityWuhu 241002China

The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this *** following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution *** results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient ***,the excess molar volume initially decreases,reaches a minimum,and then *** rules of radial distribution functions(RDFs)of characteristic atoms are *** increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then *** indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.

关键词： Pyridinium ionic liquids Thermodynamic properties Molecular dynamics simulation Radial distribution functions

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：