检索结果-南通市图书馆

A method for detecting two-dimensional plane stress distribution in basin-type insulator based on critically refracted longitudinal wave

引用

High Voltage 2024年第1期9卷 105-116页

作者： Zhaoyang Kang Fuqiang Ren Hongru Zhang Jingjing Yang Kaining Hou Qingquan Li Dongxin He Hongshun Liu Yongzhi Zhao Huaxin Wen Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment School of Electrical EngineeringShandong UniversityJinanChina Shandong Electrical Engineering&Equipment Group Co.Ltd JinanChina SDEE Hitachi High-voltage Switchgear Co. LtdJinanChina

Basin-type insulator often has small cracks due to stress concentration.The current method cannot accurately reflect the stress condition of the insulator to find the stress concentration areas.To solve these problems,a method for detecting two-dimensional plane stress(δ_(1) andδ_(2))within different depth ranges in a basin-type insulator is proposed based on critically refracted longitudinal(LCR)wave.First,the acoustoelastic equation characterising the relationship between the variation of LCR wave propagation time and the plane stress was derived.Next,the propagation characteristics of LCR wave in epoxy resin samples were investigated.Then,the stress distribution within different depth ranges of the insulator subjected to hydraulic load was measured using the proposed method,including direction(θ),δ_(1) andδ_(2).The results show that the magnitude of the stress alone cannot accurately characterise the stress state.Points with equal distances to the centre have similar stress magnitudes,but their directions are not the same.With increasing depth,θremains essentially unchanged at the same location,whileδ1 andδ2 decrease,and the rate of decrease varies at different locations.Comparing the measured and simulated data,the results showed that they were in good agreement,and the maximum errors of stress value andθwere 0.69 MPa and 2.97°,respectively,which confirmed the feasibility and accuracy of the stress detection in the proposed method.

关键词： stress insulator wave

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

stress,Burnout,and Resilience:Are Teachers at Risk?

引用

International Journal of Mental Health Promotion 2023年第2期25卷 207-222页

作者： JoséLuis Moreno-Lucas Juan Pedro Martínez-Ramón Francisco Manuel Morales-Rodríguez Cecilia Ruiz-Esteban e Inmaculada Méndez Department of Developmental and Educational Psychology Campus of Excellence Mare NostrumUniversity of MurciaEspinardoMurcia30100Spain Department of Developmental and Educational Psychology University Campus of CartujaUniversity of GranadaGranada18071Spain

It is increasingly common to find alarming news related to tragic events occurring in schools around the world.Being able to deal with these situations without getting hurt is a task not suitable for everyone.In general,teachers are the ones who must deal with this type of situation in addition to other daily problems that appear in any classroom that make the level of stress to which they are subjected can become dangerous.This research aims to know the current situation of teachers in a region of southeastern Spain in terms of their level of work stress,resilience,and other associated variables,for which an ex post facto quantitative approach study was designed.For this purpose,an ad hoc sociodemographic questionnaire,and questions based on the Teaching and Learning International Survey of the Organization for Economic Co-Operation and Development,the Maslach Burnout Inventory,and the Brief Resilient Coping Scale were applied.The participating sample consisted of 470 teachers.The main findings were that 6%of teachers had burnout(high emotional exhaustion,high cynicism,and low professional effectiveness simultaneously).Resilience correlated inversely with stress,emotional exhaustion,cynicism,excessive teaching,and difficulty maintaining classroom discipline.In conclusion,knowing the needs of teachers allows us to reflect on what kind of prevention and intervention programs are necessary to improve the well-being of teachers and thus improve the quality of education.

关键词： Burnout coping resilience stress teacher

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

Mental stress, atheroma, myocardial ischaemia and injury: the link is inflammation

引用

General Psychiatry 2023年第6期36卷 454-462页

作者： Hean Teik Ong Jinghong Chen Cardiology HT Ong Heart Clinic GeorgetownPenangMalaysia Editorial Office of General Psychiatry Shanghai Mental Health CenterShanghai Jiao Tong University School of MedicineShanghaiChina Shanghai Key Laboratory of Psychotic Disorders Shanghai Jiao Tong University School of MedicineShanghaiChina

Increasing observational and experimental trial data have shownthat mental stress can lead toan increase in adverse clinical cardiovascular events.Mental stress affects the heart by inducing ischaemia and precipitating myocardial infarction(MI)or direct myocardial injury.Mental stress leads to systemic inflammation.Inflammation is known to cause rapid atheromatous plaque progression,instability and thrombosis—the classic type 1 MI.Inflammation can also lead to type 2 MI or myocarditis and injury.The published data linking systemic inflammation,mental stress and cardiovascular disease will be reviewed to establish the linkage between mind and heart,thereby highlighting the importance of holistically managing the patient,not only addressing separate organ systems.Finally,recent trial evidence showing the value of anti-inflammatory drugs in cardiovascular and mental conditions will be briefly considered.

关键词： inflammation drugs stress

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

Potential significance of CX3CR1 dynamics in stress resilience against neuronal disorders

引用

Neural Regeneration Research 2022年第10期17卷 2153-2156页

作者： Koichi Inoue Department of Integrative Anatomy Nagoya City University Graduate School of Medical SciencesNagoyaJapan

Recent findings have implicated inflammatory responses in the central nervous system in a variety of neuropsychiatric and neurodegenerative diseases,and the understanding and control of immunological responses could be a major factor of future therapeutic strategies for neurological disorders.Microglia,derived from myelogenous cells,respond to a number of stimuli and make immune responses,resulting in a prominent role as cells that act on inflammation in the central nervous system.Fractalkine(FKN or CX3CL1)signaling is an important factor that influences the inflammatory response of microglia.The receptor for FKN,CX3CR1,is usually expressed in microglia in the brain,and therefore the inflammatory response of microglia is modified by FKN.Reportedly,FKN often suppresses inflammatory responses in microglia and activation of its receptor may be effective in the treatment of inflammatory neurological disorders.However,it has also been suggested that inflammatory responses facilitated by FKN signaling aggravate neurological disorders.Thus,further studies are still required to resolve the conflicting interpretation of the protective or deleterious contribution of microglial FKN signaling.Yet notably,regulation of FKN signaling has recently been shown to be beneficial in the treatment of human diseases,although not neurological diseases.In addition,a CX3CR1 inhibitor has been developed and successfully tested in animal models,and it is expected to be in human clinical trials in the future.In this review,I describe the potential therapeutic consideration of microglial CX3CR1 dynamics through altered FKN signaling.

关键词： Alzheimer’s disease CX3CR1 fractalkine inflammation knockout mice microglia resilience SARS-CoV-2 stress stroke

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

Resilience mediates the association between alexithymia and stress in Chinese medical students during the COVID-19 pandemic

引用

General Psychiatry 2023年第1期36卷 43-49页

作者： Yuqun Zhang Tianyu Wang Shengji Jin Heng Zhang Lixia Chen Shizheng Du School of Nursing Nanjing University of Chinese MedicineNanjingJiangsuChina Department of Psychosomatics and Psychiatry Southeast UniversityNanjingJiangsuChina

Background Evidence indicates that medical students have had high rates of mental health problems,especially during the COVID-19 pandemic,which could be affected by alexithymia—a marked dysfunction in emotional awareness,social attachment and interpersonal relationships—and stress.However,psychological resilience might relieve alexithymia and stress levels.Aims This study aimed to investigate the role of resilience in alexithymia and stress in medical students.Methods A total of 470 medical students completed online and offline surveys,including the Toronto Alexithymia Scale-20(TAS-20),the Connor-Davidson Resilience Scale(CD-RISC)and the College Student stress Questionnaire(CSSQ).The data of five participants were excluded because of a lack of integrity.Mann-Whitney U test or Kruskal-Wallis test was used to compare group differences in the CD-RISC scores among categorical variables.Spearman correlation analysis was employed to evaluate the associations between resilience and alexithymia and between resilience and stress.Mediation analysis was used to test the mediating effect of resilience between alexithymia and stress.Results Of the medical students considered in the analysis,382(81.28%)were female and 88(18.72%)were male.There was a significant negative correlation between the TAS-20 scores and the total and subtotal CD-RISC scores(pstress(total effect=1.0447,pstress through resilience(effect=0.1670,95%CI:0.069 to 0.281).Conclusions Our findings suggest that resilience might effectively reduce alexithymia and stress.They also contributed to a better understanding of the mediating effects of resilience on alexithymia and stress during the COVID-19 pandemic.The evidence from these results encourages universities to focus on improving students’resilience.

关键词： emotional stress finding

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

Depression in children with nephrotic syndrome related to parents’stress,quality of life,and depression

引用

World Journal of Pediatrics 2023年第2期19卷 194-199页

作者： Hui-Mei Huang Wei He Xue-Yun Gao Hong-Li Sun Ying Bao Department of Nephrology Xi’an Children’s HospitalXi’anChina Shaanxi Institute for Pediatric Diseases Xi’an Key Laboratory of Children’s Health and DiseasesXi’an Children’s HospitalXi’anChina School of Public Health Xi’an Jiaotong UniversityXi’anChina

Nephrotic syndrome(NS)is the most common glomerular disease in children,affecting about 7-16 in 100,000 children under 16 years old worldwide[1].Children with NS often experience significant emotional and behavioral problems,especially with frequent relapses,steroid dependence,steroid resistance,or maternal distress[2].Psychological stress may trigger proteinuria in children with steroid-sensitive nephrotic syndrome[3].The presence of NS in a child also causes burden on family members,especially the mother[4],in association with psychological distress.

关键词： distress mother stress

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

Elastic impedance inversion for stress indicator in weakly orthorhombic media

引用

Petroleum Science 2022年第5期19卷 2064-2080页

作者： Guang-Zhi Zhang Rui Yang Lin Li You Zhou Huai-Zhen Chen School of Geosciences China University of Petroleum(East China)QingdaoShangdong266580China School of Ocean and Earth Science Tongji UniversityShanghai200092China Department of Geoscience University of CalgaryCalgaryAlbertaT2N 1N4Canada

Hydraulic fracturing is a crucial technology for improving permeability and production of shale reservoirs.The precise estimation of the stress distribution has a significant guidance for optimizing the placement of hydraulic fracturing.Assuming that the shale gas reservoir is a weakly anisotropic medium with orthorhombic symmetry,a new stress indicator parameterized by rock mechanical parameters and fracture parameters is firstly presented to predict the differential horizontal stress ratio in shale gas reservoirs.Then,we derive a novel simplified P-to-P reflection coefficient and a logarithmic normalized elastic impedance(EI)as a function of Young’s modulus,Poisson’s ratio,Thomsen’s WA parameterδband normal excess compliance Z_(N).Next,we adopt azimuthal EI inversion in a Bayesian framework to estimate rock mechanics parameters and fracture parameters directly on a fractured shale gas field seismic data.Finally,the stress indicator is determined by utilizing four inverted parameters.Synthetic examples demonstrate that the proposed approach produces stable parameter estimates even with moderate noise,verifying the feasibility and effectiveness of the method.Test on a field data set illustrates that the inversion results can be reasonably estimated,and the stress indicator derived by the inversion accords with the geomechanics result.Compared with the previous method,the new stress indicator has a higher capability to describe stress characteristics in the shale reservoir.We conclude that this stress evaluation procedure can provide reliable guidance for well location deployment and hydraulic fracturing reformation.

关键词： Shale reservoir stress Anisotropy Seismic inversion

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

Effect of nucleating agents on the electrical properties of cross-linked polyethylene under tensile stress

引用

High Voltage 2024年第2期9卷 429-439页

作者： Yunqi Xing Jiahao Liu Jingang Su Junwei Zha Guochang Li Ze Guo Xiaozhen Zhao Mengjia Feng State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of TechnologyTianjinChina Electric Power Research Institute of State Grid Hebei Electric Power Supply Co. Ltd.ShijiazhuangChina Beijing Advanced Innovation Center for Materials Genome Engineering School of Chemistry and Biological EngineeringUniversity of Science&Technology BeijingBeijingChina Institute of Advanced Electrical Materials Qingdao University of Science and TechnologyQingdaoChina

During the operation of high-voltage cables,external stress and residual stress can affect the aggregated structure of insulating materials and lead to significant deterioration in their electrical performance.To investigate the evolution characteristics of the electrical properties of cross-linked polyethylene(XLPE)under mechanical stress,this paper ex-plains the relationship between the aggregated structure of XLPE and its electrical properties and proposes a method for improving insulation performance under me-chanical stress.The results show that metallocene polyethylene used as a nucleating agent can promote crystallisation through heterogeneous nucleation and increase Young's modulus by non-uniform nucleation,increasing crystallinity and reducing interplanar spacing,resulting in more complete crystal forms and reduced damage to the aggregated structure during the tensile process.After nucleating agent modification,the XLPE crystallisation becomes more uniform,and interfacial adhesion forces increase.The weakened interface damage process between the amorphous and crystalline regions under tensile stress effectively inhibits the process of molecular chain polarisation turning and reduces trap density.The modified XLPE crystal structure shows a tendency towards densification and enhanced molecular chain interactions,which can reduce the damage to the aggregated structure under tensile stress,while the reduced free volume inside the material and the shortened average free path of carriers can weaken the damage of high-energy electrons to molecular chains,thereby inhibiting the process of electrical tree degradation.The results show that nucleating agents have great potential for maintaining the stable operation of XLPE cables under mechanical stress.

关键词： stress electrical damage

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

A Netnographic-Based Semantic Analysis of Tweet Contents for stress Management

引用

Computers, Materials & Continua 2022年第1期70卷 1845-1856页

作者： Jari Jussila Eman Alkhammash Norah Saleh Alghamdi Prashanth Madhala Mohammad Ayoub Khan HAMK Smart Research Unit Häme University of Applied SciencesHämeenlinna13100Finland Department of Computer Science College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia College of Computer and Information Sciences Princess Nourah bint Abdulrahman UniversityRiyadh11671Saudi Arabia Faculty of Management and Business Tampere UniversityTampere33720Finland College of Computing and Information Technologies University of BishaBisha67714Saudi Arabia

Social media platforms provide new value for markets and research companies.This article explores the use of social media data to enhance customer value propositions.The case study involves a company that develops wearable Internet of Things(IoT)devices and services for stress management.Netnography and semantic annotation for recognizing and categorizing the context of tweets are conducted to gain a better understanding of users’stress management practices.The aim is to analyze the tweets about stress management practices and to identify the context from the tweets.Thereafter,we map the tweets on pleasure and arousal to elicit customer insights.We analyzed a case study of a marketing strategy on the Twitter platform.Participants in the marketing campaign shared photos and texts about their stress management practices.Machine learning techniques were used to evaluate and estimate the emotions and contexts of the tweets posted by the campaign participants.The computational semantic analysis of the tweets was compared to the text analysis of the tweets.The content analysis of only tweet images resulted in 96%accuracy in detecting tweet context,while that of the textual content of tweets yielded an accuracy of 91%.Semantic tagging by Ontotext was able to detect correct tweet context with an accuracy of 50%.

关键词： Social media stress semantic analysis Twitter context recognition

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

stress distribution and surrounding rock control of mining near to the overlying coal pillar in the working face

引用

International Journal of Mining Science and Technology 2019年第6期29卷 881-887页

作者： Rui Gao Bin Yu Xiangbin Meng Key Laboratory of Deep Coal Resource Mining School of MinesMinistry of Education of ChinaChina University of Mining&TechnologyXuzhou 221116China Datong Coal Mine Group Co.Ltd. Datong 037000China

The occurrence of overlying coal pillar(OCP)exerts a strong effect on the stress and strain distribution of the surrounding rock in the stope.In this paper,the stress distribution characteristics are analyzed via the numerical calculation with the account of OCP presence or absence.In addition,this study revealed the joint effect of side pressure relief area of the goaf and stress concentration in OCP on the final stress distribution.Furthermore,the rules of abutment stress distribution affected by three influencing factors,namely horizontal-vertical distances between OCP and working face and buried depth of OCP,are analyzed.The functional model linking the peak stress of surrounding rock with the above influencing factors is developed.The field application of the above results proved that the rib spalling and deformation of a 2.95 m-high and 5.66 m-wide roadway could be efficiently controlled by rationally adjusting working states of the support,and adopting the hydraulic prop coordinated with the p type metal beam and anchor cable to strengthen the surrounding rock of working face and roadway,respectively.The proposed measures are considered appropriate to satisfy the safe operation requirements.

关键词： Overlying coal pillar(OCP) stress distribution Influencing factors Surrounding rock control

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：