检索结果-南通市图书馆

Implicit nonlinear FEM for steel sets in tunnels

Science China(Technological Sciences) 2023年第3期66卷 771-783页

作者： kong ci XIAO Ming YUAN QingTeng State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering Ministry of EducationWuhan UniversityWuhan 430072China

Steel sets are widely used in tunnels with unfavorable geological *** steel sets always have small dimensions and are densely installed on the excavation surface,which is why performing nonlinear analysis on steel sets in actual engineering is a challenging ***,an implicit nonlinear finite element method(FEM)for steel sets in tunnels was ***,considering the mechanical characteristics of the steel set,a mathematical model of the steel set was proposed,which can accurately reflect the arch effect of the steel ***,the stress-strain relationship of the steel set was divided into the linear elastic stage,the first yield platform stage,the nonlinear hardening stage,and the second yield platform *** combination with the mixed hardening model,a nonlinear mechanical model of the steel set was established,and its rationality was verified by a thick aluminum ring ***,for the convenience of engineering applications,steel sets were implied into rock elements,and their elastoplastic stiffness was superimposed into rock elements to reflect their supporting ***,a stress update algorithm for the steel sets in the nonlinear iterative process and a method to simulate their fracture failure were *** models were incorporated into a self-developed FEM program to conduct nonlinear analysis for steel sets in ***,the proposed method was applied in a cross-fault hydraulic *** results proved its rationality,and some conclusions of interest were *** method does not need to establish a complex solid model for steel sets,has no influence on the meshes of rock elements,and can simulate the whole process of steel sets from the linear elastic stage to the nonlinear hardening stage and finally to the fracture failure ***,it may be a convenient method of simulating steel sets in tunnels.

关键词： steel sets mathematical model nonlinear mechanical model implicit simulation method

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

A 5′tRNA-Ala-derived small RNA regulates anti-fungal defense in plants

引用

Science China(Life Sciences) 2022年第1期65卷 1-15页

作者： Hanqing Gu Bi Lian Yuxiang Yuan ci kong Yan Li Chang Liu Yijun Qi Center for Plant Biology School of Life SciencesTsinghua UniversityBeijing 100084China Tsinghua University-Peking University Joint Center for Life Sciences Tsinghua UniversityBeijing 100084China

Apart from their primordial role in protein synthesis,t RNAs can be cleaved to produce t RNA-derived small RNAs(ts RNAs).The biological functions of ts RNAs in plants remain largely *** this study,we developed Rtc B ligation-based small RNA(s RNA)sequencing,a method that captures and distinguishes between 3′-2′,3′-cyclic-phosphate(c P)/phosphate(P)-terminated s RNAs and 3′-OH-terminated s RNAs,and profiled 5′ts RNAs and 5′t RNA halves in Arabidopsis *** found that Arabidopsis 5′ts RNAs and 5′t RNA halves predominantly contain a c P at the 3′end and require S-like RNase 1(RNS1)and RNS3 for their *** of the most abundant 5′ts RNAs,5′ts R-Ala,by associating with AGO1,negatively regulates Cytochrome P45071 A13(CYP71 A13)expression and camalexin biosynthesis to repress anti-fungal ***,5′ts R-Ala is downregulated upon fungal *** study provides a global view of 5′ts RNAs and 5′t RNA halves in Arabidopsis and unravels an important role of a 5′ts RNA in regulating anti-fungal defense.

关键词： tRNA-derived small RNAs small RNA sequencing RNase T2 CYP71A13 disease 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

地下洞室复杂水工结构的数值配筋方法

引用

中南大学学报（自然科学版） 2021年第12期52卷 4394-4404页

作者：孔词肖明武汉大学水资源与水电工程科学国家重点实验室湖北武汉430072

为实现地下洞室复杂水工结构的快速、准确配筋,提出一种基于有限元计算结果的数值配筋方法。首先,采用三维损伤非线性有限元,考虑围岩与衬砌的联合承载作用,提出地下洞室复杂水工结构与围岩相互作用的非线性损伤分析方法;其次,基于平面... 详细信息

为实现地下洞室复杂水工结构的快速、准确配筋,提出一种基于有限元计算结果的数值配筋方法。首先,采用三维损伤非线性有限元,考虑围岩与衬砌的联合承载作用,提出地下洞室复杂水工结构与围岩相互作用的非线性损伤分析方法;其次,基于平面和六面体单元相交的拓扑关系,提取地下洞室复杂水工结构任意断面轮廓线和相应配筋截面;第三,基于有限元计算结构应力,构建分段二次插值函数,获得复杂配筋截面的非线性应力分布图形,在此基础上按照现有规范进行结构配筋;最后,采用Python编程语言和AutoCAD开发自动化配筋软件平台,并将该方法应用于拉哇水电站复杂闸室结构的配筋实践。研究结果表明:本文提出的方法对水工结构的各种复杂断面均具备较好的适应性,能够实现“杆系结构”和“非杆系结构”的自动化配筋计算和结果绘制;所构建的截面应力分布图形能够反映结构在复杂受力情况下的非线性应力分布特性;该方法能够为地下工程中的复杂水工结构的配筋设计提供一个有效手段。

关键词：水工结构自动化数值配筋围岩承载轮廓提取方法应力分布图形软件平台

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

区域尺度地埋管地源热泵与能源地下结构开采浅层地热能评价综述

引用

岩土力学 2024年第5期45卷 1265-1283页

作者：孔纲强常洪林王天赐杨庆河海大学岩土力学与堤坝工程教育部重点实验室江苏南京210098 大连理工大学海岸和近海工程国家重点实验室辽宁大连116024

随着浅层地热能的大规模开发利用,针对地埋管地源热泵和能源地下结构的研究正由单个、单体尺度逐渐转向区域尺度。相较于地埋管地源热泵,能源地下结构占地面积小、成本低,在大规模城市建设及地下空间开发中具有良好的优势。从热物性参... 详细信息

随着浅层地热能的大规模开发利用,针对地埋管地源热泵和能源地下结构的研究正由单个、单体尺度逐渐转向区域尺度。相较于地埋管地源热泵,能源地下结构占地面积小、成本低,在大规模城市建设及地下空间开发中具有良好的优势。从热物性参数和地下城市热岛效应两方面总结浅层地热能理论潜力现有研究成果,简述浅层地热能的开发形式,重点针对区域尺度地埋管地源热泵与能源地下结构的适应性评价进行系统综述,从适宜性分区、热交换潜力、满足建筑物能源需求效果三方面建立相应的区域尺度能源地下结构评价体系,以我国山东临朐县和德国巴登-符腾堡州地埋管地源热泵及我国南京大学仙林校区能量桩的区域性研究为案例进行深入分析,归纳当前研究中存在的问题,并对区域尺度能源地下结构的下一步研究进行展望。

关键词：地埋管地源热泵能源地下结构浅层地热能区域尺度评价

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

Effects of Potassium-Solubilizing Bacteria on Growth, Antioxidant Activity and Expression of Related Genes in Fritillaria taipaiensis P. Y. Li

引用

Phyton-International Journal of Experimental Botany 2024年第4期93卷 789-806页

作者： Jiaqi Lang Mingyan Ye Ya Luo Yueheng Wang Zhifen Shi Xiaotian kong Xuan Li Nong Zhou Chongqing Engineering Laboratory of Green Planting and Deep Processing of Famous-Region Drug in the Three Gorges Reservoir Region College of Biology and Food EngineeringChongqing Three Gorges UniversityChongqing404120China College of Modern Chinese Medicine Industry Chengdu University of Traditional Chinese MedicineChengdu611130China College of Pharmacy Dali UniversityDali671000China

This study aimed to examine the effects of inoculating Fritillaria taipaiensis *** leaves with different strains ofpotassium-solubilizing bacteria (KSB), or combinations thereof, focusing on aspects of photosynthesis and physiologicaland biochemical characteristics. At present, some studies have only studied the rhizosphere microbialcommunity characteristics of F. taipaiensis and have not discussed the effects of different microbial species on thegrowth promotion of F. taipaiensis. This paper will start from the perspective of potassium-solubilizing bacteria toconduct an in-depth study. Seed cultivation commenced at the base with three different KSBs in early October2022. The growth of F. taipaiensis leaves was observed after different treatments. Both single-plant and compoundinoculations were executed. A total of eight treatment groups were established, with aseptic fertilizer and sterilizedsoil functioning as the control group. The results reveal that intercellular CO_(2) concentration (ci), stomatal conductance(Gs), and transpiration rate (Tr) were at their apex in the S7 group. Most treatment groups exhibited anincrease in leaf area, photosynthetic pigment content, soluble sugar, soluble protein, Superoxide Dismutase(SOD), Peroxidase (POD), Catalase (CAT) activities, and proline content. The expression levels of POD, SOD,and CAT genes were evaluated, following inoculation with different KSB. The highest was the S7 group. Theinoculation with various KSB, or combinations thereof, appears to bolster the growth and development of F. *** composite inoculation group S7, comprising Bacillus cereus, Burkholderia cepacia, and Bacillus subtilis,manifested the most favorable impact on the diverse indices of F. taipaiensis, thereby furnishing valuableinsights for the selection of bacterial fertilizer in the artificial cultivation of F. taipaiensis.

关键词： Fritillaria taipaiensis bacteria antioxidant enzyme genes leaf physiology and biochemistry photosynthetic characteristics

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

Evaluation of dry eye disease symptomatology and mental health status among patients with different COVID-19 statuses

引用

International Journal of Ophthalmology(English edition) 2024年第5期17卷 822-830页

作者： Fang Ruan Wen-Jun kong Qian Fan Hong-Wei Dong Wei Zhang Wen-Bin Wei Ying Jie Department of Ophthalmology Beijing You’an HospitalCapital Medical UniversityBeijing Infectious Eye Disease Diagnosis and Treatment CenterBeijing 100069China Beijing Tongren Eye Center Beijing Tongren HospitalCapital Medical UniversityBeijing Institute of OphthalmologyBeijing Ophthalmology and Visual Sciences Key LabBeijing 100730China Tianjin Eye Hospital Tianjin Key Lab of Ophthalmology and Visual ScienceTianjin Eye InstituteNankai University Affiliated Eye HospitalNankai University Eye InstituteNankai UniversityClinical College of OphthalmologyTianjin Medical UniversityTianjin 300020China

AIM:To evaluate dry eye disease(DED)symptomatology and mental health status in different COVID-19 ***:A cross-sectional observational design was *** 123 eligible adults(46.34%of men,age range,18-59y)with COVID-19 included in the study from August to November,*** Surface Disease Index(OSDI),Five-item Dry Eye Questionnaire(DEQ-5),Hospital Anxiety and Depression Scale(HADS),and Pittsburgh Sleep Quality Index(PSQI)were used in this ***:OSDI scores were 6.82(1.25,15.91)in asymptomatic carriers,7.35(2.50,18.38)in mild cases,and 16.67(4.43,28.04)in recurrent cases,with 30.00%,35.56%,and 57.89%,respectively evaluated as having DED symptoms(χ2=7.049,P=0.029).DEQ-5 score varied from 2.00(0,6.00)in asymptomatic carriers,3.00(0,8.00)in mild cases,and 8.00(5.00,10.00)in recurrent cases,with 27.50%,33.33%,and 55.26%,respectively assessed as having DED symptoms(χ2=8.532,P=0.014).The prevalence of clinical anxiety(50.00%)and depression(47.37%)symptoms were also significantly higher in patients with recurrent infection(χ2=24.541,Pci),1.631-7.979;P=0.033]and DEQ-5 scores(odds ratio,3.353;95%ci,1.038-8.834;P=0.043),whereas having a fixed occupation was a protective factor for OSDI scores(odds ratio,0.088;95%ci,0.022-0.360;P=0.001)and DEQ-5 scores(odds ratio,0.126;95%ci,0.039-0.405;P=0.001).CONCLUSION:Patients with recurrent COVID-19 have more severe symptoms of DED,anxiety,and depression.

关键词： COVID-19 dry eye disease recurrent infection mental health

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

Effect of resistant starch supplementation on the diversity and composition of human gut microbiota: A systematic review and meta-analysis

引用

Food Science and Human Wellness 2024年

作者： Jiaxin Xu Haocun kong Caiming Li Xiaofeng Ban Zhaofeng Li Collaborative Innovation Center of Food Safety and Quality Control Jiangnan University School of Food Science and Technology Jiangnan University State Key Laboratory of Food Science and Technology Jiangnan University

Resistant starch (RS) has attracted much researchers’ attention because of its health-beneficial effects. Gut microbiota obviously shapes human health， but the effects of RS supplementation on the changes of human gut microbiota remain unclear. This observational meta-analysis aimed to reveal the effects of RS intake on alpha diversity and composition of gut microbiota through meta-analysis. Two independent authors systematically searched articles from inception until February 2023 on four electronic databases. Twenty-four highly relevant trials were included conforming to Preferred Reporting Items for Systematic reviews and Meta-Analysis protocol， and a total of 816 individuals were included. Significant heterogeneity analyses revealed that RS intake notably decreased Shannon index (WMD: –0.11; 95% ci: –0.21， –0.01)， and stimulated the composition of health promoting bacteria genera， including Bifidobacterium (WMD: 1.75; 95% ci: 0.39， 3.11; WMD: 0.36; 95% ci: 0.04， 0.69)， Faecalibacterium (WMD: 0.70; 95% ci: 0.20， 1.20; ES: 0.91; 95% ci: 0.60， 1.23)， and Prevotella (WMD: 0.35; 95% ci: 0.01， 0.69). Taken together， the present study revealed that changes in the gut microbiota diversity and genera were correlated with RS supplementation， which may contribute to benefits in human health.

关键词：

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

Effect of plateletcrit and methylenetetrahydrofolate reductase(MTHFR)C677T genotypes on folic acid efficacy in stroke prevention

引用

Signal Transduction and Targeted Therapy 2024年第6期9卷 2694-2701页

作者： Yuncong Shi Zhengzhipeng Zhang Binyan Wang Yu Wang Xiangyi kong Yong Sun Aimin Li Yimin Cui Yan Zhang Jianping Li Yong Huo Hui Huang Cardiovascular Department The Eighth Affiliated HospitalJoint Laboratory of Guangdong-Hong Kong-Macao Universities for Nutritional Metabolism and Precise Prevention and Control of Major Chronic DiseasesSun Yat-sen UniversityShenzhenChina Shenzhen Evergreen Medical Institute ShenzhenChina Shenzhen Tailored Medical Laboratory ShenzhenChina Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityBeijingChina Department of Neurosurgery The First Affiliated Hospital of Kangda College of Nanjing Medical UniversityLianyungangChina Institute of Clinical Pharmacology Peking University First HospitalBeijingChina Department of Cardiology Peking University First HospitalBeijingChina

Previous studies have shown that low platelet count combined with high plasma total homocysteine(tHcy)increased stroke risk and can be lowered by 73% with folic ***,the combined role of other platelet activation parameters and the methylenetetrahydrofolate reductase(MTHFR)C677T genotypes on stroke risk and folic acid treatment benefit remain to be *** study aimed to investigate if platelet activation parameters and MTHFR genotypes jointly impact folic acid treatment efficacy in first stroke *** were derived from the China Stroke Primary Prevention *** study includes a total of 11,185 adult hypertensive patients with relevant platelet activation parameters and MTHFR genotype *** simultaneously considering both platelet activation parameters(plateletcrit,platelet count,mean platelet volume,platelet distribution width)and MTHFR genotypes,patients with both low plateletcrit(Q1)and the TT genotype had the highest stroke incidence rate(5.6%)in the enalapril *** subgroup significantly benefited from folic acid treatment,with a 66% reduction in first stroke(HR:0.34;95%ci:0.14-0.82;p=0.016).Consistently,the subgroup with low plateletcrit(Q1)and the CC/CT genotype also benefited from folic acid treatment(HR:0.40;95%ci:0.23-0.70;p=0.001).In Chinese hypertensive adults,low plateletcrit can identify those who may greatly benefit from folic acid treatment,in particular,those with the TT genotype,a subpopulation known to have the highest stroke risk.

关键词： prevention treatment MTHFR

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

Development of a radiomics model to discriminate ammonium urate stones from uric acid stones in vivo:A remedy for the diagnostic pitfall of dual-energy computed tomography

引用

Chinese Medical Journal 2024年第9期137卷 1095-1104页

作者： Junjiong Zheng Jie Zhang Jinhua Cai Yuhui Yao Sihong Lu Zhuo Wu Zhaoxi Cai Aierken Tuerxun Jesur Batur Jian Huang Jianqiu kong Tianxin Lin Department of Urology Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene RegulationGuangdong Provincial Clinical Research Center for Urological DiseasesGuangzhouGuangdong 510120China Department of Neurology Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhouGuangdong 510120China Department of Radiology Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhouGuangdong 510120China Department of Urology The First People’s Hospital of Kashgar PrefectureKashgarXinjiang 844000China

Background:Dual-energy computed tomography(DECT)is purported to accurately distinguish uric acid stones from non-uric acid ***,whether DECT can accurately discriminate ammonium urate stones from uric acid stones remains ***,we aimed to explore whether they can be accurately identified by DECT and to develop a radiomics model to assist in distinguishing ***:This research included two *** the first purpose to evaluate the accuracy of DECT in the diagnosis of uric acid stones,178 urolithiasis patients who underwent preoperative DECT between September 2016 and December 2019 were *** model construction,93,40,and 109 eligible urolithiasis patients treated between February 2013 and October 2022 were assigned to the training,internal validation,and external validation sets,*** features were extracted from non-contrast CT images,and the least absolute shrinkage and selection operator(LASSO)algorithm was used to develop a radiomics ***,a radiomics model incorporating the radiomics signature and clinical predictors was *** performance of the model(discrimination,calibration,and clinical usefulness)was ***:When patients with ammonium urate stones were included in the analysis,the accuracy of DECT in the diagnosis of uric acid stones was significantly ***-two percent of ammonium urate stones were mistakenly diagnosed as uric acid stones by DECT.A radiomics model incorporating the radiomics signature,urine pH value,and urine white blood cell count was *** model achieved good calibration and discrimination{area under the receiver operating characteristic curve(AUC;95%confidence interval[ci]),0.944(0.899-0.989)},which was internally and externally validated with AUCs of 0.895(95%ci,0.796-0.995)and 0.870(95%ci,0.769-0.972),*** curve analysis revealed the clinical usefulness of the ***:DECT cannot accurately differentiate amm

关键词： Ammonium urate Dual-energy scanned projection radiography Radiomics Uric acid Urolithiasis

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

硫铁矿制酸企业强制性清洁生产审核潜力分析

引用

环境科学导刊 2013年第3期32卷 80-87页

作者：孔慈明曲靖市环境科学研究所云南曲靖655000

在认真的现状调研和审核重点物料平衡的基础上,结合企业的实际情况、生产特点、产排污特点,从影响生产的原辅料和能源、技术工艺、设备、过程控制、产品、废弃物、管理、员工八个方面分析了硫铁矿制酸企业强制性清洁生产审核潜力。

关键词：硫铁矿制酸清洁生产审核潜力分析

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：