检索结果-南通市图书馆

Mechanical and hydraulic properties of carbonate rock:The critical role of porosity

Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 814-825页

作者： kam ng J.Carlos Santamarina Department of Civil and Architectural Engineering and Construction Management University of WyomingLaramieWY82071USA Physical Science and Engineering Division King Abdullah University of Science and TechnologyThuwal23955-6900Saudi Arabia

Carbonate rocks are extensively used in civil infrastructure and play a critical role in geoenergy geoengineering,either as hydrocarbon reservoirs or potential repositories for CO_(2)geological *** genesis and diagenetic overprint determine the properties of carbonate *** study combines recent data gathered from Madison Limestone and an extensive dataset compiled from published sources to analyze the hydraulic and mechanical properties of limestone carbonate *** models and data analyses recognize the inherently granular genesis of carbonate rocks and explain the strong dependency of physical properties on *** asymptotically-correct power model in terms of(1-Ф/Ф*)a is a good approximation to global trends of unconfined stiffness E and unconfined compressive strength UCS,cohesive intercept in Mohr-Coulomb failure envelopes,and the brittle-toductile transition *** power model is the analytical solution for the mechanical properties of percolating granular *** adopted a limiting granular porosityФ*=0.5 for all models,which was consistent with the loosest packing of monosize *** fitted power model has exponent(α=2)in agreement with percolation theory and highlights the sensitivity of mechanical properties to *** and models confirm a porosity-independent ratio between unconfined stiffness and strength,and the ratio follows a log-normal distribution with mean(E/UCS)≈*** high angle of internal shear strength measured for carbonate rocks reflects delayed contact failure with increased confinement,and it is not sensitive to *** spans more than six orders of *** size controls pore size and determines the reference permeability k^(*)at the limiting porosityФ*=*** a given grain size from fine to coarse-grained dominant carbonates,permeability is very sensitive to changes in porosity,suggesting preferential changes in the internal pore network during compaction.

关键词： Rock porosity Carbonate permeability Rock unconfined stiffness Unconfined compressive strength(UCS)

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

Expanded pore-emanated cracking model for brittle failure of sedimentary rocks under triaxial compression

引用

Journal of Rock Mechanics and Geotechnical Engineering 2024年第12期16卷 5050-5060页

作者： Esraa M.Alomari kam ng Lokendra Khatri Department of Civil and Architectural Engineering and Construction Management University of WyomingLaramieWY82071USA Kiewit Corporations ColliersvilleNew YorkNY13747USA

Brittle fracture and its relationship to deformation and strength have been a fundamental area of research in rock *** paper presents an expanded pore-emanated cracking model to better understand the fracture behaviors and predict the compressive strength of sedimentary *** proposed model is developed to account for a triaxial compression condition using the triaxial compression test results on sandstone,limestone and siltstone samples from Wyoming,USA and experimental data on sedimentary rocks collected from published *** normalized critical crack length is determined from the proposed model through which the peak compressive strength is estimated when the stress intensity at the crack tip reaches a critical value called the fracture *** indicate that the rock porosity and pore radius have an inverse relationship with the compressive *** the porosity-permeability relationship,the pore radius is calculated in terms of porosity and grain ***,the effect of grain size is implicitly included in the model and negatively correlated with the compressive ***,a new approach is proposed for the estimation of fracture toughness based on the pore radius and confining *** predicted compressive strengths from the proposed model show a good agreement with the measured strengths with a mean bias(*** ratio of the measured to predicted strengths)of *** influence ofφand K_(IC)onσ1 was thoroughly studied using parametric *** study concludes that the effect ofφis more prominent than K_(IC)onσ*** a constant porosity of 0.1,the stress ratio decreases from 0.0082 to 0.0078 when K_(IC)increases from 0.1 to 0.2,indicating a 5%decrease in stress ***,at a constant K_(IC)of 0.1,the stress ratio increases from 0.0082 to 0.014 when the porosity increases from 0.1 to 0.2,indicating 71%increases in stress ratio and therefore compressive strength.

关键词： Compressive strength Mode I fracture toughness Porosity Pore radius Confining pressure

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

The STRARCH STRessed-ARCH Building System From Concept To Application

The STRARCH STRessed-ARCH Building System From Concept To Ap...

引用

第二届全国现代结构工程学术研讨会

作者： Peter William Key ng kam Tong STRARCH International Limited SydneyAustralia*** Chung ＆ Ng Consulting EngineersHong Kong Chief EngineerHainan Airlines Construction ＆ Development Co Lid

＜正＞STRARCH International Limited is an Australian public listed company specializing in the design and construction of large clear span steel *** recently completed a 99.6m span hangar for Hainan Airlines in *** paper describes the unique patented stressed-arch building system,discusses the advantages for particular building types and relates these advantages to actual solutions embodied in a number of recently constructed *** paper provides a balanced perspective on both design and construction issues and should be of interest to both academics and the practicing engineer.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

城市更新理念与中国城市现实

引用

城市规划学刊 2009年第2期 75-82页

作者：翟斌庆伍美琴香港大学城市规划及设计系

改革开放加速了城市化,也暴露了中国城市急需更新以应付社会经济的转型。文章比较了中西方"城市更新"的概念,总结了西方城市更新的经验,认为城市更新机制以及城市管治体系变革,是保证城市更新的综合目标得以实现的根本途径。

关键词：城市更新城市改造更新模式更新机制

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Mitochondrial therapeutics and mitochondrial transfer for neurodegenerative diseases and aging

引用

Neural Regeneration Research 2025年第3期20卷 794-796页

作者： Neville ng Michelle Newbery Nicole Miles Lezanne Ooi Molecular Horizons and School of Chemistry and Molecular Bioscience University of WollongongWollongongNSWAustralia

Mitochondrial dysfunction and neurodegeneration:Progressive neurodegenerative diseases affect a significant proportion of the population;in a single year,there are as many as 276 million disabilities and 9 million dea... 详细信息

关键词： degenerative diseases Mitochondrial

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

Robust interface and excellent as-built mechanical properties of Ti–6Al–4V fabricated through laser-aided additive manufacturing with powder and wire

引用

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 154-168页

作者： Fei Weng Guijun Bi Youxiang Chew Shang Sui Chaolin Tan Zhenglin Du Jinlong Su Fern Lan ng Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong Engineering&Technology Research Center for Superhard MaterialSchool of Materials Science and EngineeringShandong UniversityJinan 250061China Institute of Intelligent Manufacturing Guangdong Academy of SciencesGuangzhou 510095China Singapore Institute of Manufacturing Technology 5 Cleantech Loop636732Singapore

The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),*** the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire *** characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α *** mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and *** mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat *** fracture occurred within the interfacial area,further suggesting the robust *** findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.

关键词： laser-aided additive manufacturing powder deposition wire deposition interfacial characteristic mechanical behavior

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

城市社区公共环境的使用后评价与满意度研究——以西安为例

引用

建筑与文化 2018年第12期 171-173页

作者：翟斌庆李骥伍美琴西安交通大学人居环境与建筑工程学院荷兰埃因霍温理工大学建筑与城市设计工程系香港中文大学地理与资源管理系

基于"使用后评价"与"可持续性指标"理论,文章以西安市新旧两个社区为例,针对社区公共环境的居民满意度开展对比研究。文章首先讨论了公共环境在社区营建中的重要性;其次采用可持续性指标,针对居民满意度进行调查与数据分析;最后,基于分... 详细信息

基于"使用后评价"与"可持续性指标"理论,文章以西安市新旧两个社区为例,针对社区公共环境的居民满意度开展对比研究。文章首先讨论了公共环境在社区营建中的重要性;其次采用可持续性指标,针对居民满意度进行调查与数据分析;最后,基于分析结果,文章对当前我国城市新旧社区公共环境的可持续更新与发展提出了若干建议。

关键词：社区公共环境使用后评价可持续性指标满意度调查西安

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

Incremental expectation maximization principal component analysis for missing value imputation for coevolving EEG data

引用

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第8期12卷 687-697页

作者： Sun Hee KIM Hyung Jeong YAng kam Swee ng Department of Computer Science Chonnam National University

Missing values occur in bio-signal processing for various reasons,including technical problems or biological *** missing values are then either simply excluded or substituted with estimated values for further *** the missing signal values are estimated for electroencephalography (EEG) signals,an example where electrical signals arrive quickly and successively,rapid processing of high-speed data is required for immediate decision *** this study,we propose an incremental expectation maximization principal component analysis (iEMPCA) method that automatically estimates missing values from multivariable EEG time series data without requiring a whole and complete data *** proposed method solves the problem of a biased model,which inevitably results from simply removing incomplete data rather than estimating them,and thus reduces the loss of information by incorporating missing values in real *** using an incremental approach,the proposed method alsominimizes memory usage and processing time of continuously arriving *** results show that the proposed method assigns more accurate missing values than previous methods.

关键词： Electroencephalography (EEG) Missing value imputation Hidden pattern discovery Expectation maximization Principal component analysis

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

On the first negative Hecke eigenvalue of an automorphic representation of GL_(2)(A_(Q))

引用

Science China Mathematics 2021年第11期64卷 2381-2394页

作者： Yuk-kam Lau Ming Ho ng Hengcai Tang Yingnan Wang Department of Mathematics The University of Hong KongHong KongChina Department of Mathematics The Chinese University of Hong KongHong KongChina Institute of Modern Mathematics School of Mathematics and StatisticsHenan UniversityKaifeng 475004China Shenzhen Key Laboratory of Advanced Machine Learning and Applications College of Mathematics and StatisticsShenzhen UniversityShenzhen 518060China

Letπbe a self-dual irreducible cuspidal automorphic representation of GL_(2)(A_(Q))with trivial central *** Hecke eigenvalue λπ(n)is a real multiplicative function in *** show that λπ(n)<0 for some n< 详细信息

关键词： automorphic representation Hecke eigenvalue Maass cusp form sign change

来源：

维普期刊数据库

同方期刊数据库

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

Calibration of the Solar X-ray Detector on-board the Macao Science Satellite-1B for Soft X-ray Detection

引用

Science China Earth Sciences 2025年第1期68卷 11-26页

作者： Man-Hei ng Xiaoping ZHAng Jianwu CHEN Yongqiang SHI Fuchang ZUO Wenxi PEng Weichun FU Liansheng LI Pengwei LUO Chi-Long TAng Guozheng ZHAng Zhiwu MEI Li WAng Cunhui LI Jiaming OU Yanyan XU State Key Laboratory of Lunar and Planetary Sciences Macau University of Science and Technology China National Space Administration (CNSA) Macau Center for Space Exploration and Science Space Optoelectronic Measurement and Perception Laboratory Beijing Institute of Control Engineering Institute of High Energy Physics Chinese Academy of Sciences Science and Technology on Vacuum Technology and Physics Laboratory Lanzhou Institute of Physics

The Solar X-ray Detector(SXD) on-board the Macao Science Satellite-1B(MSS-1B) was successfully launched via the Chinese Long March-2C rocket on 21 May 2023, and commenced operations in early June of the same year. The MSS-1B/Soft X-ray Detection Units(SXDUs) employ two silicon drift detectors(SDDs), providing a wide range of energy spectra spanning from 0.7 to 24 keV. Notably, the SXDUs deliver a high-resolution capability of 0.14 keV@5.9 keV and operate with a time cadence of 1 second. Here, we perform thorough calibrations of the MSS-1B/SXDUs, employing a combination of ground experiments and simulations. In addition, quantitative analysis comparing the flux measurements obtained by the MSS-1B/SXDUs to the data collected by the Geostationary Operational Environmental Satellite(GOES), provides compelling evidence of their consistency. Furthermore, the preliminary spectral analysis results showcase the robustness and expected performance of the MSS-1B/SXDUs, unlocking their potential for facilitating the study of dynamic evolution of solar flares. Moreover, the innovative MSS-1B/Solar X-ray Detector facilitates concurrent observations of solar soft and hard X-rays, thereby making valuable contributions to the advancements in solar research.

关键词： Macao Science Satellite-1B (MSS-1B) Calibration Solar X-Ray Detector Spectrometer Soft X-rays Solar flares Solar abundances

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

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：