检索结果-南通市图书馆

FRP筋增强海水海砂混凝土材料与构件耐久性能综述

在线全文

学校读者我要写书评

暂无评论

建筑科学与工程学报 2024年第2期41卷 17-30页

作者：张凯建王琳福州大学土木工程学院福建福州350108

将纤维增强复合材料(FRP)应用在海水海砂混凝土(SSC)中可避免氯离子引起的钢筋腐蚀,但FRP增强海水海砂混凝土(FRP-SSC)结构在恶劣环境中仍存在耐久性问题。依据现有文献研究成果,梳理了海洋环境下FRP筋、SSC以及FRP-SSC构件的耐久性。... 详细信息

将纤维增强复合材料(FRP)应用在海水海砂混凝土(SSC)中可避免氯离子引起的钢筋腐蚀,但FRP增强海水海砂混凝土(FRP-SSC)结构在恶劣环境中仍存在耐久性问题。依据现有文献研究成果,梳理了海洋环境下FRP筋、SSC以及FRP-SSC构件的耐久性。结果表明:在混凝土的碱性环境以及海水海砂中盐离子的共同作用下,FRP筋的力学性能退化程度与变异性提高,FRP筋与SSC的黏结强度降低;海水和海砂中盐离子的引入加快了水化反应,提高了SSC的密实度与耐久性,提高了SSC的耐久性;海洋环境作用导致FRP筋力学性能退化及FRP筋/钢-FRP复合筋(SFCB)与SSC的黏结强度降低,削弱了SSC构件承载力,改变了构件破坏模式,SSC构件承载力随再生粗骨料(RCA)取代率提高而降低;建议以FRP筋与SSC力学性能变异性量化和基于时变可靠度的构件设计方法作为今后进一步研究的方向。

关键词： FRP筋耐久性海水海砂混凝土破坏模式转变钢-FRP复合筋

Compressive behavior and microstructure of concrete mixed with natural seawater and sea sand

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2021年第6期15卷 1347-1357页

作者： Qinghai XIE Jianzhuang XIAO kaijian zhang Zhongling ZONG Department of Structural Engineering Tongji UniversityShanghai 200092China School of Civil and Ocean Engineering Jiangsu Ocean UniversityLianyungang 222005China

Noncorrosive reinforcement materials facilitate producing structural concrete with seawater and sea *** study investigated the properties of seawater and sea sand concrete(SSC),considering the curing age(3,7,14,21,28,60,and 150 d)and strength grade(C30,C40,and C60).The compressive behavior of SSC was obtained by compressive tests and digital image correction(DIC)*** electron microscope(SEM)and X-ray powder diffraction(XRD)methods were applied to understand the microstructure and hydration products of cement in *** revealed a 30%decrease in compressive strength for C30 and C40 SSC from 60 to 150 d,and a less than 5%decrease for C60 from 28 to 150 *** results revealed significant cracking and crushing from 80%to 100%of compressive *** images showed a more compact microstructure in higher strength *** patterns identified Friedel’s salt phase due to the chlorides brought by seawater and sea *** findings in this study can provide more insights into the microstructure of SSC along with its short-and long-term compressive behavior.

关键词： seawater and sea sand concrete compressive strength strain field microstructure hydration products

Fundamental Issues Towards Unified Design Theory of Recycled and Natural Aggregate Concrete Components

在线全文

学校读者我要写书评

暂无评论

Engineering 2023年第10期29卷 188-197页

作者： Jianzhuang Xiao kaijian zhang Tao Ding Qingtian zhang Xuwen Xiao Department of Structural Engineering Tongji UniversityShanghai 200092China College of Civil Engineering and Architecture Guangxi UniversityNanning 530004China College of Civil Engineering Fuzhou UniversityFuzhou 350116China

In the past 20 years,recycled aggregate concrete(RAC),as a type of low-carbon concrete,has become a worldwide focus of ***,the design methodology for RAC structural components remains a ***,demands for a unified design of natural aggregate concrete(NAC)and RAC components have been ***,this study analyses the necessity of a unified design theory and provides an in-depth demonstration of the strength determination,compressive constitutive relationship,and design method of concrete *** coefficient of variation of RAC strength is found to be generally higher than that of NAC *** compressive and tensile strengths of RAC can be defined and determined using the same method as that used for *** uniaxial compressive constitutive relationship between NAC and RAC has a unified mathematical ***,the elastic modulus of RAC decreases,and its brittleness exhibits an increasing trend compared with that of ***,to unify the design formulae of RAC and NAC components for bearing capacity,modification factors for RAC components are proposed considering safety and ***,the feasibility of the proposed unified time-dependent design theory is demonstrated in terms of conceptual design and structural measures considering the effects of strength degradation and reinforcement *** is believed that this study enriches and develops the basic theory of concrete structures.

关键词： Recycled aggregate concrete(RAC) Natural aggregate concrete(NAC) Strength determination Constitutive relation Reliability Unified design theory

SMART/ASTC dynamic soft reduction technology and its application on the bloom continuous caster at Pangang

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

Journal of University of Science and Technology Beijing 2006年第2期13卷 121-124页

作者： Guijun Li kaijian zhang Chuanfi Han Yong Chen Guoyan Zhao Kaike Cai Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China Panzhihua Iron ＆ Steel Co. Panzhihua Sichuan 617000 China

The SMART/ASTC dynamic soft reduction technology of VAI and its application on the 6-strand bloom continuous caster at Pangang, China are presented. The operation results show that soft reduction technology is effective to improve the inner quality of continuously cast blooms. At Pangang, both the central porosity and the central segregation ratings are no more than 1.0, the central shrinkage cavity rating is no more than 0.5, and the central segregation index of carbon is no more than 1.05. Rails made from the blooms have excellent quality and are used for high-speed tracks.

关键词： bloom continuous casting dynamic soft reduction heavy rail steel

AFSTGCN:Prediction for multivariate time series using an adaptive fused spatial-temporal graph convolutional network

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第2期10卷 292-303页

作者： Yuteng Xiao kaijian Xia Hongsheng Yin Yu-Dong zhang Zhenjiang Qian Zhaoyang Liu Yuehan Liang Xiaodan Li School of Information and Control Engineering China University of Mining and TechnologyXuzhou221116China Department of Informatics University of LeicesterLeicesterLE17RHUK The Affiliated Changshu Hospital of Soochow University Changshu215500China School of Computer Science and Engineering Changshu Institute of TechnologySuzhou215500China

The prediction for Multivariate Time Series(MTS)explores the interrelationships among variables at historical moments,extracts their relevant characteristics,and is widely used in finance,weather,complex industries and other ***,it is important to construct a digital twin ***,existing methods do not take full advantage of the potential properties of variables,which results in poor predicted *** this paper,we propose the Adaptive Fused Spatial-Temporal Graph Convolutional Network(AFSTGCN).First,to address the problem of the unknown spatial-temporal structure,we construct the Adaptive Fused Spatial-Temporal Graph(AFSTG)***,we fuse the spatial-temporal graph based on the interrelationship of spatial ***,we construct the adaptive adjacency matrix of the spatial-temporal graph using node embedding ***,to overcome the insufficient extraction of disordered correlation features,we construct the Adaptive Fused Spatial-Temporal Graph Convolutional(AFSTGC)*** module forces the reordering of disordered temporal,spatial and spatial-temporal dependencies into rule-like *** dynamically and synchronously acquires potential temporal,spatial and spatial-temporal correlations,thereby fully extracting rich hierarchical feature information to enhance the predicted *** on different types of MTS datasets demonstrate that the model achieves state-of-the-art single-step and multi-step performance compared with eight other deep learning models.

关键词： Adaptive adjacency matrix Digital twin Graph convolutional network Multivariate time series prediction Spatial-temporal graph

Wetting front migration model of ion-adsorption rare earth during the multi-hole unsaturated liquid injection

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

Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 483-496页

作者： Yu Wang Xiaojun Wang Yuchen Qiu Hao Wang Gang Li kaijian Hu Wen Zhong Zhongqun Guo Bing Li Chunlei zhang Guangxiang Ye Jiangxi Key Laboratory of Mining Engineering Jiangxi University of Science and TechnologyGanzhou341000China School of Resources and Environment Engineering Jiangxi University of Science and TechnologyGanzhou341000China School of Civil Engineering and Surveying&Mapping Engineering Jiangxi University of Science and TechnologyGanzhou341000China Ganzhou Nonferrous Metallurgy Research Institute Ganzhou341000China

In the process of ion-adsorption rare earth ore leaching,the migration characteristics of the wetting front in multi-hole injection holes and the influence of wetting front intersection effect on the migration distance of wetting fronts are still ***,wetting front migration distance and leaching time are usually required to optimize the leaching *** this study,wetting front migration tests of ionadsorption rare earth ores during the multi-hole fluid injection(the spacing between injection holes was 10 cm,12 cm and 14 cm)and single-hole fluid injection were completed under the constant water head *** the pre-intersection stage,the wetting front migration laws of ion-adsorption rare earth ores during the multi-hole fluid injection and single-hole fluid injection were *** the postintersection stage,the intersection accelerated the wetting front *** using the Darcy’s law,the intersection effect of wetting fronts during the multi-hole liquid injection was transformed into the water head height directly above the ***,based on the Green-Ampt model,a wetting front migration model of ion-adsorption rare earth ores during the multi-hole unsaturated liquid injection was *** analysis results showed that the proposed model can accurately simulate the infiltration process under experimental *** research results enrich the infiltration law and theory of ion-adsorption rare earth ores during the multi-hole liquid injection,and this study provides a scientific basis for optimizing the liquid injection well pattern parameters of ion-adsorption rare earth in situ leaching in the future.

关键词： Ion-adsorption rare earth ore Multi-hole unsaturated liquid injection In situ leaching Intersection effect Calculation model

海水海砂再生混凝土单轴受压应力-应变全曲线

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

同济大学学报（自然科学版） 2021年第12期49卷 1738-1745页

作者：张凯建肖建庄张青天同济大学土木工程学院上海200092 福州大学土木工程学院福建福州350116 同济大学土木工程防灾国家重点实验室上海200092

为探究海水海砂再生混凝土(SSRAC)力学性能,设计了不同配合比下海水海砂再生混凝土棱柱体试件,并进行了单轴受压应力‒应变全曲线测试。在试验加载应变率10^(-5)s^(-1)和10^(-2)s^(-1)下,得到了试件的破坏模式,分析了峰值应力、峰值应变... 详细信息

为探究海水海砂再生混凝土(SSRAC)力学性能,设计了不同配合比下海水海砂再生混凝土棱柱体试件,并进行了单轴受压应力‒应变全曲线测试。在试验加载应变率10^(-5)s^(-1)和10^(-2)s^(-1)下,得到了试件的破坏模式,分析了峰值应力、峰值应变和弹性模量的变化规律以及应变率、再生粗骨料(RCA)取代率和贝壳含量对上述指标的影响规律,讨论了海水海砂再生混凝土的动态增长因子(DIF)。基于电子计算机断层扫描(CT)测试得到了海水海砂再生混凝土内部的孔隙分布,对应力‒应变曲线的特征指标变化趋势进行了解释。最后,在现有再生混凝土单轴受压本构模型的基础上,考虑特征指标的动态增长因子,通过修正下降段形状系数得到了预测应力‒应变全曲线。

关键词：再生混凝土(RAC) 海水海砂应变率孔隙率应力‒应变全曲线

端粒选择性延长与胰腺神经内分泌瘤预后的研究进展

在线全文

学校读者我要写书评

暂无评论

中华病理学杂志 2023年第4期52卷 431-434页

作者：张凯健张智弘南京医科大学第一附属医院病理科南京210029

端粒选择性延长(alternative lengthening of telomeres,ALT)是一种不依赖端粒酶活性从而克服端粒缩短,导致肿瘤细胞生长和细胞增殖的机制。在胰腺神经内分泌瘤(pancreatic neuroendocrine tumor,PanNET)中发现了ALT,且其与2个染色质重... 详细信息

端粒选择性延长(alternative lengthening of telomeres,ALT)是一种不依赖端粒酶活性从而克服端粒缩短,导致肿瘤细胞生长和细胞增殖的机制。在胰腺神经内分泌瘤(pancreatic neuroendocrine tumor,PanNET)中发现了ALT,且其与2个染色质重塑基因——α-地中海贫血/智力迟钝X连锁染色质重塑(alpha-thalassemia/mental retardation X-linked chromatin remodeler,ATRX)和死亡域相关蛋白(death domain-associated protein,DAXX)的突变存在明显相关性。ALT是PanNET的预后指标,有助于识别“高风险”患者;同时ALT支持神经内分泌瘤的胰腺起源。因此,本文就ALT与PanNET患者预后的研究进展进行综述,以提高对该分子标志物的认识。

关键词：胰腺神经内分泌瘤智力迟钝 X连锁预后指标 death 细胞增殖端粒分子标志物

在线全文

学校读者我要写书评

暂无评论

基于可靠度的再生混凝土梁最小配筋率研究

同济大学学报（自然科学版） 2016年第2期44卷 213-219页

作者：张凯建肖建庄丁陶胡博同济大学土木工程学院上海200092 同济大学土木工程防灾国家重点实验室上海200092

为考察再生混凝土强度变异性对再生混凝土梁最小配筋率的影响,以普通混凝土梁最小配筋率为参照,保持规范目标可靠指标不变,分析了再生混凝土梁受弯时的最小配筋率和受剪时的最小配箍率,并将结果与普通混凝土梁进行了对比.分析结果表明,... 详细信息

为考察再生混凝土强度变异性对再生混凝土梁最小配筋率的影响,以普通混凝土梁最小配筋率为参照,保持规范目标可靠指标不变,分析了再生混凝土梁受弯时的最小配筋率和受剪时的最小配箍率,并将结果与普通混凝土梁进行了对比.分析结果表明,再生混凝土梁受弯时,由于钢筋的存在,再生混凝土强度的变异性对其受弯承载力变异性的影响较小,再生混凝土梁的最小配筋率提高很小.对于再生混凝土梁受剪,当再生混凝土强度变异系数为0.2时,C30再生混凝土梁的最小配箍率为0.17%,相比较普通混凝土梁约增加32.0%.通过合理增加配筋可以保证再生混凝土梁的受弯、受剪可靠指标与普通混凝土梁一致.

关键词：再生混凝土梁强度变异性最小配筋率最小配箍率可靠指标