The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedu...The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedule in preliminary design approved by the central government and the investment can be controlled within the total budget of the preliminary design. The Changjiang Water Resources Commission, taking charge of the general design jobs of the TGP, has consistently paid attention to the project quality in the first place and carried out large amount of investigation, design and scientific research work. This paper makes an overall summarization and presentation on important technical issues in the design, such as dam, powerhouse structure, permanent ship locks, ship lift, project safety monitoring, main river closure and the 2nd stage cofferdam, mechanical and electric design etc., and put forwards a lot of suggestions about optimizing design schemes and measures for smoothing away construction difficulties in accordance with construction progress.展开更多
This study addresses the effectiveness of a simple stiffness tailoring concept to delay damage initiation, control damage progression, and improve residual strength in tensile-loaded composite plates with a central ci...This study addresses the effectiveness of a simple stiffness tailoring concept to delay damage initiation, control damage progression, and improve residual strength in tensile-loaded composite plates with a central circular cutout. The tailoring concept is to simply reposit all axially oriented （0°） material into regions near the edge of the plate away from the cutout. This tailoring is done in a way so as not to affect the weight of the plate. This accomplishes several beneficial changes in the way that the plate resists loading with no increases in material cost or weight. Lowering the axial stiffness of the laminate surrounding the cutout lowers the stress concentration. Increasing the axial stiffness near edges of the plate attracts loading away from the vicinity of the cutout to further lower stresses in the critical cutout region. This study focuses on in-plane response including damage progression and residual strength as a function of the degree of tailoring and cutout size. Strength and stiffness properties typical of IM7/8551-7 preperg material were assumed and a modified version of the Hashin failure criteria was used to identify the local damage. Results show that tailoring can significantly increase the damage initiation load and the residual strength. In some cases, observed evidence shows that tailoring performs as a damage arrest mechanism.展开更多
Through reviewing the development history of reservoir hydraulic fracturing technology, this paper demonstrated the latest research progress at home and abroad and summarized six technical gaps between China and the w...Through reviewing the development history of reservoir hydraulic fracturing technology, this paper demonstrated the latest research progress at home and abroad and summarized six technical gaps between China and the world, that is fracture propagation mechanism, fracturing software development, fracturing vehicle equipment, downhole tools temperature and pressure resistance, proppant replacement and big data information database. The technical difficulties include lack of geological-engineering deep integration, unclear factors on horizontal well multi-fracture propagation, difficulty in reducing construction costs, environment protection pressure, lack of new experimental and field test equipment, immature techniques for fracturing fluid, and low efficacy of factorized fracturing equipment. We proposed six suggestions on China’s future reservoir hydraulic fracturing technology:(1) strengthen the mechanism study of unconventional reservoir hydraulic fracturing;(2) accelerate the development of geological-engineering integration software;(3) promote the upgrading of EOR fracturing techniques;(4) carry out low-cost multi-functional fracturing fluid formula experiment;(5) complete high-efficiency fracturing equipment;(6) build big database, informational and remote decision-making system of hydraulic fracturing.展开更多
对1981—2025年儿童参与式设计研究重点文献进行对比研究后作可视化分析并总结其特点。以Web of Science核心合集、Scopus、Ebsco三大数据库(2824篇)以及CNKI数据库中的期刊和硕博士论文(共53篇)为研究对象,采用可视化文献分析软件CiteS...对1981—2025年儿童参与式设计研究重点文献进行对比研究后作可视化分析并总结其特点。以Web of Science核心合集、Scopus、Ebsco三大数据库(2824篇)以及CNKI数据库中的期刊和硕博士论文(共53篇)为研究对象,采用可视化文献分析软件CiteSpace对国内外儿童参与式设计研究进行对比分析,总结归纳国内外儿童参与式设计的研究发展进程及热点趋势,并结合一般参与式设计的特点和8个核心要点对比分析儿童参与式设计特点。国内儿童参与式设计研究尚处于发展阶段,相关文献数量有限,研究热度与国外相比仍有较大差距。国内研究机构与作者间合作相对松散,而国外已经形成比较完善的合作网络。在研究热点上,由于国情不同,国外儿童参与式设计研究在过去长期侧重于医疗健康领域,而国内主要关注教育领域。然而,当前国内外儿童参与式设计研究热点都逐渐转向社区营造相关领域。此外,儿童参与式设计与一般参与式设计在研究热点、利益相关者和研究主体表达能力上存在差异。在儿童参与式项目建构中,需更多地考虑每一阶段的儿童权利和游戏化互动体验设计,确保儿童在项目中的体验与创意产出。展开更多
文摘The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedule in preliminary design approved by the central government and the investment can be controlled within the total budget of the preliminary design. The Changjiang Water Resources Commission, taking charge of the general design jobs of the TGP, has consistently paid attention to the project quality in the first place and carried out large amount of investigation, design and scientific research work. This paper makes an overall summarization and presentation on important technical issues in the design, such as dam, powerhouse structure, permanent ship locks, ship lift, project safety monitoring, main river closure and the 2nd stage cofferdam, mechanical and electric design etc., and put forwards a lot of suggestions about optimizing design schemes and measures for smoothing away construction difficulties in accordance with construction progress.
基金NASA,the State of South Carolina,and Clemson University through the EPSCoR grant 'Development and Enhancement of Research Capability for Aircraft Structures and Materials'.
文摘This study addresses the effectiveness of a simple stiffness tailoring concept to delay damage initiation, control damage progression, and improve residual strength in tensile-loaded composite plates with a central circular cutout. The tailoring concept is to simply reposit all axially oriented （0°） material into regions near the edge of the plate away from the cutout. This tailoring is done in a way so as not to affect the weight of the plate. This accomplishes several beneficial changes in the way that the plate resists loading with no increases in material cost or weight. Lowering the axial stiffness of the laminate surrounding the cutout lowers the stress concentration. Increasing the axial stiffness near edges of the plate attracts loading away from the vicinity of the cutout to further lower stresses in the critical cutout region. This study focuses on in-plane response including damage progression and residual strength as a function of the degree of tailoring and cutout size. Strength and stiffness properties typical of IM7/8551-7 preperg material were assumed and a modified version of the Hashin failure criteria was used to identify the local damage. Results show that tailoring can significantly increase the damage initiation load and the residual strength. In some cases, observed evidence shows that tailoring performs as a damage arrest mechanism.
基金Supported by the China National Science and Technology Major Project(2016ZX05023)
文摘Through reviewing the development history of reservoir hydraulic fracturing technology, this paper demonstrated the latest research progress at home and abroad and summarized six technical gaps between China and the world, that is fracture propagation mechanism, fracturing software development, fracturing vehicle equipment, downhole tools temperature and pressure resistance, proppant replacement and big data information database. The technical difficulties include lack of geological-engineering deep integration, unclear factors on horizontal well multi-fracture propagation, difficulty in reducing construction costs, environment protection pressure, lack of new experimental and field test equipment, immature techniques for fracturing fluid, and low efficacy of factorized fracturing equipment. We proposed six suggestions on China’s future reservoir hydraulic fracturing technology:(1) strengthen the mechanism study of unconventional reservoir hydraulic fracturing;(2) accelerate the development of geological-engineering integration software;(3) promote the upgrading of EOR fracturing techniques;(4) carry out low-cost multi-functional fracturing fluid formula experiment;(5) complete high-efficiency fracturing equipment;(6) build big database, informational and remote decision-making system of hydraulic fracturing.
文摘对1981—2025年儿童参与式设计研究重点文献进行对比研究后作可视化分析并总结其特点。以Web of Science核心合集、Scopus、Ebsco三大数据库(2824篇)以及CNKI数据库中的期刊和硕博士论文(共53篇)为研究对象,采用可视化文献分析软件CiteSpace对国内外儿童参与式设计研究进行对比分析,总结归纳国内外儿童参与式设计的研究发展进程及热点趋势,并结合一般参与式设计的特点和8个核心要点对比分析儿童参与式设计特点。国内儿童参与式设计研究尚处于发展阶段,相关文献数量有限,研究热度与国外相比仍有较大差距。国内研究机构与作者间合作相对松散,而国外已经形成比较完善的合作网络。在研究热点上,由于国情不同,国外儿童参与式设计研究在过去长期侧重于医疗健康领域,而国内主要关注教育领域。然而,当前国内外儿童参与式设计研究热点都逐渐转向社区营造相关领域。此外,儿童参与式设计与一般参与式设计在研究热点、利益相关者和研究主体表达能力上存在差异。在儿童参与式项目建构中,需更多地考虑每一阶段的儿童权利和游戏化互动体验设计,确保儿童在项目中的体验与创意产出。
