期刊文献+
共找到8,831篇文章
< 1 2 250 >
每页显示 20 50 100
Saint-Venant torsion analysis of bars with rectangular cross-section and effective coating layers
1
作者 H.TEIMOORI R.T.FAAL R.DAS 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第2期237-252,共16页
This paper investigates the torsion analysis of coated bars with a rectangular cross-section. Two opposite faces of a bar are coated by two isotropie layers with different materials of the original substrate that are ... This paper investigates the torsion analysis of coated bars with a rectangular cross-section. Two opposite faces of a bar are coated by two isotropie layers with different materials of the original substrate that are perfectly bonded to the bar. With the Saint- Venant torsion theory, the governing equation of the problem in terms of the warping function is established and solved using the finite Fourier cosine transform. The state of stress on the cross-section, warping of the cross-section, and torsional rigidity of the bar are evaluated. Effects of thickness of the coating layers and material properties on these quantities are investigated. A set of graphs are provided that can be used to determine the coating thicknesses and material properties so as to keep the maximum von Mises stress on the cross-section below an allowable value for effective use of the coating layer. 展开更多
关键词 Saint-Venant torsion rectangular cross-section coating layer torsional rigidity
在线阅读 下载PDF
Effects of temperature-dependent viscosity variation on entropy generation, heat and fluid flow through a porous-saturated duct of rectangular cross-section 被引量:1
2
作者 K.Hooman H.Gurgenci 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第1期69-78,共10页
Effect of temperature-dependent viscosity on fully developed forced convection in a duct of rectangular cross-section occupied by a fluid-saturated porous medium is investigated analytically. The Darcy flow model is a... Effect of temperature-dependent viscosity on fully developed forced convection in a duct of rectangular cross-section occupied by a fluid-saturated porous medium is investigated analytically. The Darcy flow model is applied and the viscosity-temperature relation is assumed to be an inverse-linear one. The case of uniform heat flux on the walls, i.e. the H boundary condition in the terminology of Kays and Crawford [12], is treated. For the case of a fluid whose viscosity decreases with temperature, it is found that the effect of the variation is to increase the Nusselt number for heated walls. Having found the velocity and the temperature distribution, the second law of thermodynamics is invoked to find the local and average entropy generation rate. Expressions for the entropy generation rate, the Bejan number, the heat transfer irreversibility, and the fluid flow irreversibility are presented in terms of the Brinkman number, the Péclet number, the viscosity variation number, the dimensionless wall heat flux, and the aspect ratio (width to height ratio). These expressions let a parametric study of the problem based on which it is observed that the entropy generated due to flow in a duct of square cross-section is more than those of rectangular counterparts while increasing the aspect ratio decreases the entropy generation rate similar to what previously reported for the clear flow case by Ratts and Rant [14]. 展开更多
关键词 entropy generation rate forced convection porous medium rectangular duct temperature-dependent viscosity
在线阅读 下载PDF
A Cross-sectional Analysis of Prenatal Bisphenol an Exposure and Pregnancy Characteristics in Northeastern Yunnan, China
3
作者 Xuemei Ding Jin Fu +6 位作者 Guoju Wan Liu Yang Xinyue Wen Ruijiao Yuan Yanqiong Liu Yao Wu Jie Gao 《Journal of Clinical and Nursing Research》 2026年第1期231-234,共4页
Objective:To assess prenatal Bisphenol A(BPA)exposure levels and explore their preliminary associations with maternal and fetal characteristics in a population from Northeastern Yunnan.Methods:A cross-sectional analys... Objective:To assess prenatal Bisphenol A(BPA)exposure levels and explore their preliminary associations with maternal and fetal characteristics in a population from Northeastern Yunnan.Methods:A cross-sectional analysis was performed using data and urine samples from 70 pregnant women in their third trimester recruited at Qujing Central Hospital.Urinary BPA was measured by HPLC-MS/MS.Participants were stratified into high and low BPA exposure groups based on the median concentration.Results:BPA was detected in all samples(100%)with a median concentration of 2.41μg/L(IQR:0.68-4.96).The high BPA exposure group(≥2.41μg/L)had a significantly higher proportion of gestational diabetes mellitus(GDM)(42.9%vs.17.1%,p=0.021)and a lower median fetal birth weight(3250 g vs.3450 g,p=0.048)compared to the low exposure group.Conclusion:This pilot study reveals ubiquitous BPA exposure in pregnant women from Northeastern Yunnan.The observed preliminary associations with GDM and reduced fetal birth weight warrant further investigation in larger,longitudinal studies. 展开更多
关键词 Bisphenol A PREGNANCY Exposure assessment cross-sectional study China
暂未订购
Simulation Analysis of the Extrusion Process for Complex Cross-Sectional Profiles of Ultra-High Strength AluminumAlloy
4
作者 Tianxia Zou Yilin Sun +3 位作者 Fuhao Fan Zhen Zheng Yanjin Xu Baoshuai Han 《Computers, Materials & Continua》 2026年第4期471-491,共21页
Ultra-high-strength aluminumalloy profile is an ideal choice for aerospace structuralmaterials due to its excellent specific strength and corrosion resistance.However,issues such as uneven metal flow,stress concentrat... Ultra-high-strength aluminumalloy profile is an ideal choice for aerospace structuralmaterials due to its excellent specific strength and corrosion resistance.However,issues such as uneven metal flow,stress concentration,and forming defects are prone to occur during their extrusion.This study focuses on an Al-Zn-Mg-Cu ultra-high-strength aluminum alloy profile with a double-U,multi-cavity thin-walled structure.Firstly,hot compression experiments were conducted at temperatures of 350○C,400○C,and 450○C,with strain rates of 0.01 and 1.0 s^(−1),to investigate the plastic deformation behavior of the material.Subsequently,a 3D coupled thermo-mechanical extrusion simulation model was established using Deform-3D to systematically analyze the influence of die structure and process parameters on metal flow velocity,effective stress/strain,and temperature distribution.The simulation revealed significant velocity differences,stress concentration,and uneven temperature distribution.Key parameters,including mesh density,extrusion ratio,die fillet,and bearing length,were optimized through full-factorial experiments.This optimization,combined with a stepped flow-guiding die design,effectively improved the metal flow pattern during extrusion.Trial production based on both the initial and optimized parameters were carried out.A comparative analysis demonstrates that the optimized scheme results in a final profile whose cross-section matches the target design closely,with complete filling of complex features and no obvious forming defects.This research provides a valuable reference for the extrusion process optimization and die design of complex-section profiles made from ultra-high-strength aluminum alloys. 展开更多
关键词 Ultra-high-strength aluminum alloy EXTRUSION complex cross-section die optimization process optimization
在线阅读 下载PDF
The Increasing Trends of Short and Long Sleep Duration among Chinese Adults from 2010 to 2018:A Repeated Nationally Representative Cross-sectional Survey
5
作者 Yun Chen Lan Wang +12 位作者 Mei Zhang Sifan Hu Yan Shao Xiao Zhang Chun Li Jie Chen Zhenping Zhao Yanhong Dong Lin Lu Maigeng Zhou Limin Wang Junliang Yuan Hongqiang Sun 《Biomedical and Environmental Sciences》 2026年第1期46-59,共14页
Objective This study aimed to determine the temporal trends in sleep duration among Chinese adults.Methods In this series of repeated nationally representative cross-sectional surveys(China Chronic Disease and Risk Fa... Objective This study aimed to determine the temporal trends in sleep duration among Chinese adults.Methods In this series of repeated nationally representative cross-sectional surveys(China Chronic Disease and Risk Factors Surveillance)conducted between 2010 and 2018,a total of 645,420 adult participants(97,741 in 2010;175,749 in 2013;187,777 in 2015;and 184,153 in 2018)were included in the trend analysis.Linear and logistic regression models were utilized to assess trends in sleep duration.Results In 2018,the estimated overall mean sleep duration among the Chinese adult population was7.58(SD,1.45)hours per day,with no significant trend from 2010.A significant increase in short sleep duration(≤6 hours)was observed in the total population,from 15.3%(95%CI:14.1%–16.5%)in 2010 to18.5%(95%CI:17.7%–19.3%)in 2018(P<0.001).Similarly,the trend in long sleep duration(>9 hours)was also significant,increasing in weighted prevalence from 7.2%(95%CI:6.3%–8.1%)in 2010 to 9.0%(95%CI:8.2%–9.9%)in 2018(P<0.001).Conclusion The prevalence of both short and long sleep durations significantly increased among Chinese adults from 2010 to 2018,highlighting the urgency of health initiatives to promote optimal sleep duration in China. 展开更多
关键词 Sleep duration Trend analysis Repeated cross-sectional study Nationally representative survey CCDRFS
暂未订购
Estimation of cross-sectional areas of individual tree stems using remotely collected data
6
作者 Gabriel Lessa Lavagnoli Gilson Fernandes da Silva +3 位作者 Giovanni Correia Vieira André Quintao Almeida Adriano Ribeiro de Mendonca Carlos Pedro Boechat Soares 《Journal of Forestry Research》 2026年第1期216-229,共14页
We investigated the impact of convexity and isoperimetric deficits on the accuracy of sectional area estimates of tree stems using traditional methods(caliper,tape,formulas based on stem diameter and circumference).In... We investigated the impact of convexity and isoperimetric deficits on the accuracy of sectional area estimates of tree stems using traditional methods(caliper,tape,formulas based on stem diameter and circumference).In two complementary experiments,the use of photographs to estimate cross-sectional areas was first validated,then the use of a caliper and diameter tape was computer-simulated.The results indicated that the photographic method offers high precision,with mean relative errors below 0.1%,minimal deviation,and no significant bias,and the traditional methods led to substantial and systematic errors,with deviations from circularity and convexity significantly increasing the errors in area estimation. 展开更多
关键词 Tree cross-sectional area measurement Isoperimetric decit Convexity decit Photographic estimation Forest mensuration Stem geometry Error analysis
在线阅读 下载PDF
Cross-sectional distortion behaviors of thin-walled rectangular tube in rotary-draw bending process 被引量:8
7
作者 赵刚要 刘郁丽 +1 位作者 杨合 卢彩红 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第3期484-489,共6页
The cross-sectional distortion usually appears during rotary-draw bending process of thin-walled rectangular tube with small bending radius.To study the cross-sectional distortion of the tube,a three-dimensional finit... The cross-sectional distortion usually appears during rotary-draw bending process of thin-walled rectangular tube with small bending radius.To study the cross-sectional distortion of the tube,a three-dimensional finite-element model of the process was developed based on ABAQUS/Explicit code and its reliability was validated by experiment.Then,the cross-sectional distortion behaviors of the tube were investigated.The results show that a zone of larger circumferential stress appears on the tube when bending angle reaches 30°.And in the larger circumferential stress zone,the sagging phenomenon is produced obviously.The maximum cross-sectional distortion is located in the larger circumferential stress zone and the angle between the plane of maximum cross-sectional distortion and the bending reference plane is about 50°.The position of the maximum cross-sectional distortion keeps almost unchanged with the variation of the clearances between dies and tube. 展开更多
关键词 thin-walled rectangular tube aluminum alloy 3A21 rotary-draw bending cross-sectional distortion die clearance
在线阅读 下载PDF
Cross-sectional deformation behavior of double-ridged rectangular tube with fillers in different stages of H-typed bending 被引量:5
8
作者 Chunmei LIU Yuli LIU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第6期1799-1811,共13页
The bent double-ridged rectangular tube(DRRT)with high forming quality is helpful to improve the microwave transmission accuracy.For reducing the cross-sectional deformation in the H-typed bending process,in addition ... The bent double-ridged rectangular tube(DRRT)with high forming quality is helpful to improve the microwave transmission accuracy.For reducing the cross-sectional deformation in the H-typed bending process,in addition to using rigid mandrel to support the inside of tube,ridge groove fillers are also added to restrict the deformation of ridge grooves.Because of the change of stress and strain state of bent tube in bending,rigid mandrel retracting and specially twicespringback stages,and the springback of fillers,the cross-sectional deformation of tube in each stage may be different.Therefore,based on the ABAQUS platform,the finite element models(FEM)for H-typed bending,mandrel retracting and twice-springback stages of H96 DRRT with fillers were established and validated.It is found that,for the height and width deformation of tube and spacing deformation of ridge grooves,retraction of mandrel can make the distribution of these deformations more uniform along the bending direction.The first springback can reduce these deformations significantly,which should be emphasized.But the second springback only increases them by less amount,which can be ignored.The smaller height deformation of ridge groove and filler can be neglected. 展开更多
关键词 cross-sectional deformation FE simulation H96 double-ridged rectangular tube H-typed rotary draw bending Ridge groove fillers Twice-springback stage
原文传递
Association between Non-high-density Lipoprotein Cholesterol to High-density Lipoprotein Cholesterol Ratio(NHHR)and Stroke among Adults in the USA:A Cross-Sectional NHANES Study 被引量:3
9
作者 Haixia Ma Huaqiu Chen Peichang Wang 《Biomedical and Environmental Sciences》 2025年第1期37-46,共10页
Objective The relationship between non-high-density lipoprotein(NHDL)cholesterol to high-density lipoprotein cholesterol(HDL-C)ratio(NHHR)and stoke remains unknown.This study aimed to evaluate the association between ... Objective The relationship between non-high-density lipoprotein(NHDL)cholesterol to high-density lipoprotein cholesterol(HDL-C)ratio(NHHR)and stoke remains unknown.This study aimed to evaluate the association between the adult NHHR and stroke occurrence in the United States of America(USA).Methods To clarify the relationship between the NHHR and stroke risk,this study used a multivariable logistic regression model and a restricted cubic spline(RCS)model to investigate the association between the NHHR and stroke,and data from the National Health and Nutrition Examination Survey(NHANES)from 2005 to 2018.Subgroup and sensitivity analyses were conducted to test the robustness of the results.Results This study included 29,928 adult participants,of which 1,165 participants had a history of stroke.Logistic regression analysis of variables demonstrated a positive association between NHHR and stroke(OR 1.24,95%CI:1.03-1.50,P=0.026).Compared with the lowest reference group of NHHR,participants in the second,third,and fourth quartile had a significantly increased risk of stroke after full adjustments(OR:1.35,95%CI:1.08-1.69)(OR:1.83,95%CI:1.42-2.36)(OR:2.04,95%CI:1.50-2.79).In the total population,a nonlinear dose-response relationship was observed between the NHHR and stroke risk(P non-linearity=0.002).This association remained significant in several subgroup analyses.Further investigation of the NHHR may enhance our understanding of stroke prevention and treatment.Conclusion Our findings suggest a positive correlation between the NHHR and an increased prevalence of stroke,potentially serving as a novel predictive factor for stroke.Timely intervention and management of the NHHR may effectively mitigate stroke occurrence.Prospective studies are required to validate this association and further explore the underlying biological mechanisms. 展开更多
关键词 NHHR STROKE NHANES cross-sectional study
暂未订购
Cross-sectional deformation of H96 brass double-ridged rectangular tube in rotary draw bending process with different yield criteria 被引量:2
10
作者 Yangyang XIA Yuli LIU Mengmeng LIU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第6期1788-1798,共11页
Different yield criterion has great difference in predicting the deformation of tube with different material.In order to improve the prediction accuracy of the cross-sectional deformation of the double-ridged rectangu... Different yield criterion has great difference in predicting the deformation of tube with different material.In order to improve the prediction accuracy of the cross-sectional deformation of the double-ridged rectangular tube(DRRT)during rotary draw bending(RDB)process,Mises isotropic yield criterion,Hill’48 and Barlat/Lian anisotropic yield criteria commonly used in practical engineering are introduced to simulate RDB of DRRT.The inverse method combining uniaxial tensile test of whole tube and response surface methodology was proposed to identify the parameters of Hill’48 and Barlat/Lian yield criteria of small-sized H96 brass extrusion DRRT as well.Then based on ABAQUS/Explicit platform,the FE models of RDB process of DRRT considering Mises,Hill’48 and Barlat/Lian yield criteria were built.The results show that:The variation trend of cross-sectional deformation ratio is same when using different yield criteria.The cross-sectional deformation ratio by using Mises yield criterion is close to that by using Hill’48 yield criterion.However,there is a quite difference between by using Barlat/Lian yield criterion and by using Mises or Hill’48 yield criteria.The prediction values of cross-sectional height deformation by using three yield criteria all underestimate the experiment ones,and the prediction values of cross-sectional width deformation overestimate the experiment ones.By comparing the simulation results of cross-sectional deformation of the DRRT with different yield criteria and experiment ones,Barlat/Lian yield criterion is found to be suitable for describing the RDB process of DRRT. 展开更多
关键词 Anisotropy yield criterion cross-sectional deformation H96 double-ridged rectangular tube H-type rotary draw bending Inverse method
原文传递
Research on Multi-Level Automatic Filling Optimization Design Method for Layered Cross-Sectional Layout of Umbilical 被引量:1
11
作者 YIN Xu FAN Zhi-rui +4 位作者 CAO Dong-hui LIU Yu-jie LI Meng-shu YAN Jun YANG Zhi-xun 《China Ocean Engineering》 2025年第5期891-903,共13页
The umbilical,a key component in offshore energy extraction,plays a vital role in ensuring the stable operation of the entire production system.The extensive variety of cross-sectional components creates highly comple... The umbilical,a key component in offshore energy extraction,plays a vital role in ensuring the stable operation of the entire production system.The extensive variety of cross-sectional components creates highly complex layout combinations.Furthermore,due to constraints in component quantity and geometry within the cross-sectional layout,filler bodies must be incorporated to maintain cross-section performance.Conventional design approaches based on manual experience suffer from inefficiency,high variability,and difficulties in quantification.This paper presents a multi-level automatic filling optimization design method for umbilical cross-sectional layouts to address these limitations.Initially,the research establishes a multi-objective optimization model that considers compactness,balance,and wear resistance of the cross-section,employing an enhanced genetic algorithm to achieve a near-optimal layout.Subsequently,the study implements an image processing-based vacancy detection technique to accurately identify cross-sectional gaps.To manage the variability and diversity of these vacant regions,the research introduces a multi-level filling method that strategically selects and places filler bodies of varying dimensions,overcoming the constraints of uniform-size fillers.Additionally,the method incorporates a hierarchical strategy that subdivides the complex cross-section into multiple layers,enabling layer-by-layer optimization and filling.This approach reduces manufac-turing equipment requirements while ensuring practical production process feasibility.The methodology is validated through a specific umbilical case study.The results demonstrate improvements in compactness,balance,and wear resistance compared with the initial cross-section,offering novel insights and valuable references for filler design in umbilical cross-sections. 展开更多
关键词 UMBILICAL cross-sectional layout multi-level filling layered layout optimization design
在线阅读 下载PDF
Gut microbial characteristics of the damp-heat constitution:a population-based multicenter cross-sectional study 被引量:2
12
作者 LI Tianxing ZHU Linghui +9 位作者 WANG Xueke TANG Jun YANG Lingling PANG Guoming LI Huang WANG Liying DONG Yang ZHAO Shipeng LI Yingshuai LI Lingru 《Journal of Traditional Chinese Medicine》 2025年第1期140-151,共12页
OBJECTIVE:To investigate the difference in gut microbiota between population with damp-heat constitution(DHC)and balanced constitution(BC).METHODS:A multi-centered cross-sectional casecontrol study was conducted,which... OBJECTIVE:To investigate the difference in gut microbiota between population with damp-heat constitution(DHC)and balanced constitution(BC).METHODS:A multi-centered cross-sectional casecontrol study was conducted,which included 249 participants with damp-heat constitution or balanced constitution.Baseline information of participants was collected,and stool samples were collected for gut microbiota analysis.Principal coordinate analysis,linear discriminant analysis effect size analysis,receiver operating characteristic,random forest model,and phylogenetic investigation of communities by reconstruction of unobserved states methods were used to reveal the relationship between gut microbiota and the damp-heat constitution.RESULTS:Compared to those in the BC group,the richness and diversity of the microbiota,specifically those of several short-chain fatty acid producing genera such as Barnesiella,Coprobacter,and Butyricimonas,were significantly decreased in the DHC group.Regarding biological functions,flavonoid biosynthesis,propanoate metabolism,and nucleotide sugar metabolism were suppressed,while arachidonic acid metabolism and glutathione metabolism were enriched in the DHC group.Finally,a classifier based on the microbiota was constructed to discriminate between the DHC and BC populations.CONCLUSION:The gut microbiota of the DHC population exhibits significantly reduced diversity and is closely related to inflammation,metabolic disorders,and liver steatosis,which is consistent with clinical observations,thus serving as a potential diagnostic tool for traditional Chinese medicine constitution discrimination. 展开更多
关键词 damp-heat constitution balanced constitution Traditional Chinese medicine constitution MICROBIOTA inflammatory PICRUSt multicenter study cross-sectional studies
原文传递
Occupational influences on dietary quality among postpartum women:a cross-sectional study in Beijing,China 被引量:1
13
作者 Jian Zhao Min Zhang 《Global Health Journal》 2025年第2期94-103,共10页
Objective:Postpartum nutrition plays a critical role in maternal recovery and long-term health.However,the nutritional status of working mothers in the postpartum period remains understudied.This study aimed to assess... Objective:Postpartum nutrition plays a critical role in maternal recovery and long-term health.However,the nutritional status of working mothers in the postpartum period remains understudied.This study aimed to assess the dietary quality of postpartum women in urban Beijing,identify occupational-related factors influencing their diet,and explore potential interventions to improve maternal nutrition during the postpartum period.Methods:In this cross-sectional analysis,554 women one year after delivery were recruited from ten community health centers.Sociodemographic,occupational and postpartum care variables were collected via questionnaire.Dietary intake over the preceding year was assessed using a food frequency questionnaire.The modified dietary balance index for postpartum women were used for dietary quality assessment.Results:The study revealed severe dietary imbalances among postpartum women,characterized by excessive consumption of cereals,eggs,and meats,while their intake of vegetables,fruits,and dairy products was inadequate.According to dietary balance index for postpartum women,66.25%of mothers showed varying degrees of excessive intake.45.31%of mothers experienced varying levels of insufficient intake,with only 19.86%of participants having a relatively balanced diet.Occupational differences were observed,with women in the commercial employment group showing higher levels of excessive food intake.The analysis of influencing factors showed that family monthly income,maternity leave,and postpartum care significantly affected the dietary quality.Conclusions:Postpartum women in Beijing experience widespread dietary imbalances,with both excesses and deficiencies.Occupational context and related factors significantly shape diet quality.These findings highlight the need for targeted nutritional interventions tailored to the specific challenges of different occupational groups. 展开更多
关键词 Postpartum dietary quality Dietarybalance index Occupational factors Maternal health cross-sectional study
暂未订购
Influences of maximum principal stress direction and cross-section shape on tunnel stability 被引量:1
14
作者 Xuefeng Si Zilong Zhang +4 位作者 Xibing Li Guansheng Yi Yong Luo Lihai Tan Kaifeng Han 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第4期2159-2180,共22页
To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with... To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with rectangular,circular,and D-shaped holes.Asθincreases from 0°to 60°in the rectangular hole,the left failure location shifts from the left corner to the left sidewall,the left corner,and then the floor,while the right failure location shifts from the right corner to the right sidewall,right roof corner,and then the roof.Furthermore,the initial failure vertical stress first decreases and then increases.In comparison,the failure severity in the rectangular hole decreases for variousθvalues as 30°>45°>60°>0°.With increasingθ,the fractal dimension(D)of rock slices first increases and then decreases.For the rectangular and D-shaped holes,whenθ=0°,30°,and 90°,D for the rectangular hole is less than that of the D-shaped hole.Whenθ=45°and 60°,D for the rectangular hole is greater than that of the D-shaped hole.Theoretical analysis indicates that the stress concentration at the rectangular and D-shaped corners is greater than the other areas.The failure location rotates with the rotation ofθ,and the failure occurs on the side with a high concentration of compressive stress,while the side with the tensile and compressive stresses remains relatively stable.Therefore,the fundamental reason for the rotation of failure location is the rotation of stress concentration,and the external influencing factor is the rotation ofθ. 展开更多
关键词 Maximum principal stress direction cross-section shape True-triaxial experiment Failure characteristics Fractal dimension Theoretical analysis
在线阅读 下载PDF
Characteristics and trends of bibliometric analysis on acupuncture:A cross-sectional study
15
作者 Zhi-Qiang Li Hui-Juan Cao +9 位作者 Heng Yin Yue Jiang Xue-Feng Wang Chen Shen Kun Wu Zi-Yi Qi Mei-Ling Wang You-Zhu Su Ling-Yao Kong Jian-Ping Liu 《Integrative Medicine Discovery》 2025年第3期1-11,共11页
Background:The bibliometrics of acupuncture are growing rapidly.However,the absence of reporting guidelines may lead to significant duplication and waste,thereby undermining the research’s value.To address this,a kno... Background:The bibliometrics of acupuncture are growing rapidly.However,the absence of reporting guidelines may lead to significant duplication and waste,thereby undermining the research’s value.To address this,a knowledge mapping was generated based on published studies to investigate the characteristics of bibliometric studies on acupuncture and the extent of duplicate publications,with the overarching goal of providing a comprehensive overview of the knowledge structure in this field.Methods:This cross-sectional study used three databases(PubMed,Web of Science,and Scopus)to identify relevant studies up to May 1,2024.In addition,the reference lists were retrieved as a supplement.To track research trends,we employed Microsoft Excel and R software to extract,code,and analyze information.Study selection,data extraction,and validation were performed independently by at least two reviewers.The reporting quality of included studies was assessed using the Preliminary guideline for reporting bibliometric reviews of the biomedical literature(BIBLIO).Results:Among the 6,221 bibliometric reviews examined,113 relevant publications were identified,80 focusing on various diseases/conditions.The annual number of publications has gradually increased,with the output in the past four years being 3.52 times higher than that before 2020.China(106)and Chengdu University of Traditional Chinese Medicine(16)have the highest number of publications.The most prolific author is Fan-Rong Liang,with six articles.The first bibliometric study,by Hai-Yan Li,was published in 2010.Journal of Pain Research,with 36 articles,holds the most publications.The top three diseases:diseases of the nervous system;symptoms,signs,or clinical findings not elsewhere classified;and mental,behavioral,or neurodevelopmental disorders.There may be potential duplication in research on 13 diseases/conditions,notably stroke,migraine,pain/analgesia,cancer pain,shoulder pain,facial paralysis/bell’s palsy,chronic pain,and cognitive impairment.In BIBLIO,the most frequently missing items are issues/topics(item 2),quality assessment(item 11),and descriptive findings(item 13).Conclusion:This study demonstrates that acupuncture bibliometrics is actively utilized to identify dominant diseases/conditions,aiding scholars in understand the knowledge structure and main topics.Although the number of related studies is increasing,with an average of 25 studies annually,overlap in some areas highlights the need for adherence to reporting guidelines and careful topic selection to ensure truly valuable insights and knowledge contributions.The adherence to BIBLIO’s 20 proposed items across analyzed articles,highlighting important in reporting practices. 展开更多
关键词 cross-sectional study ACUPUNCTURE BIBLIOMETRICS evidence mapping
暂未订购
Investigation of aerodynamic shape optimization of cross-sectional body of high-speed train
16
作者 PRASERT Prapamonthon SUN Zhen-xu +3 位作者 YAO Shuan-bao BAI Ye GUO Di-long YANG Guo-wei 《Journal of Central South University》 2025年第12期4660-4682,共23页
A train body's cross-sectional shape has a significant impact on aerodynamic drag and operational safety in high-speed trains(HSTs).This study extracts five design variables from a real-world HST body:height,width... A train body's cross-sectional shape has a significant impact on aerodynamic drag and operational safety in high-speed trains(HSTs).This study extracts five design variables from a real-world HST body:height,width,side arc radius,arc radius at the connection between the side and the roof,and arc radius at the connection between the side and the train's bottom.The cross-validated Kriging surrogate model and the genetic algorithm are used to perform two types of aerodynamic optimization,with the cross-sectional area as a constraint.Cross-sectional shapes are optimized in both windless and windy conditions.Numerical results indicate that in a windless environment,the aerodynamic drag coefficient of the whole train is reduced by 2.4%;in a windy condition,the aerodynamic drag coefficient of the entire vehicle is reduced by 2.4%,and the aerodynamic lateral force of the leading car is reduced by 37.8%.These suggest that a flat and wide shape helps to reduce not only overall aerodynamic drag in a windless environment but also aerodynamic load in a windy environment,which can be accomplished by reducing the area of the side wall and top region,lowering the train body's height,increasing its width,and lowering the radius of the side and top arcs. 展开更多
关键词 cross-section multi-objective optimization Kriging model aerodynamic design high-speed trains
在线阅读 下载PDF
Latent profilesof ambivalence over emotional expression in young breast cancer patients:A cross-sectional study
17
作者 Xiaocen Chen Zhao Wang +3 位作者 Sibo Wang Fang Zhang Xueyu Li Jing Zhao 《International Journal of Nursing Sciences》 2025年第4期379-385,I0004,I0005,共9页
Objectives:This study aimed to classify young breast cancer patients into distinct ambivalence over emotional expression and to explore the factors influencingthe level of ambivalence over emotional expression.Methods... Objectives:This study aimed to classify young breast cancer patients into distinct ambivalence over emotional expression and to explore the factors influencingthe level of ambivalence over emotional expression.Methods:A total of 217 young breast cancer patients were enrolled from a tertiary Grade A oncology hospital in Tianjin,China,using the convenience sampling method.All participants completed the general questionnaire,Ambivalence over Emotion Expression Questionnaire(AEQ),and Family Adapt-Ability and Cohesion Evaluation Scales-Chinese Version(FACES-CV).We employed exploratory latent profileanalysis for ambivalence over emotional expression profilingand logistic regression analysis to identify the influentialfactors Results:The results of the latent profileanalysis supported the models of four latent profiles,which were definedas“low conflict-lowexpression reflection”(19.2%),“high conflict-high inhibition expression”(43.9%),“moderate conflict-highregret expression”(18.1%),and“moderate conflict-desire understand”(18.8%).Logistic regression revealed that family cohesion,marital status,residence,per capita monthly income,and cancer stage were the influencingfactors of ambivalence over emotional expression in young breast cancer patients(P<0.05)Conclusions:Levels of ambivalence over emotional expression ameast cancer patients with breast cancer were highly heterogeneous.Medical staff should provide psychological counseling and health education tailored to the unique characteristics of emotional expression ambivalence in different patient groups to promote healthy emotional expression among patients. 展开更多
关键词 AMBIVALENCE Breast neoplasms cross-sectional studies Emotions NURSING Young adult
暂未订购
Stress wave scaling theory of bar with variable cross-section
18
作者 Xumeng Ren Shujuan Hou Xu Han 《Acta Mechanica Sinica》 2025年第10期165-178,共14页
The coconut structure exhibits inherent impact resistance,with the macroscopically ordered distribution of variable crosssection fibers in its husk playing a crucial role in stress wave propagation and scaling.Inspire... The coconut structure exhibits inherent impact resistance,with the macroscopically ordered distribution of variable crosssection fibers in its husk playing a crucial role in stress wave propagation and scaling.Inspired by the natural structure and fibers,this study proposes a stress wave propagation model for a variable cross-section bar considering viscous effects.A theoretical model for stress wave propagation in a fusiform-shaped bar with variable cross-section is established,elucidating the stress wave scaling effect observed in coconut fibers.Additionally,a quasi-one-dimensional method for analyzing and measuring stress wave propagation is introduced,and an experimental setup is assembled.Experimental validation of the stress wave scaling effect confirms the theory’s accuracy for stress wave scaling in variable cross-section bars.This research provides theoretical guidance and measurement methods for the design of space landers,automobile anti-collision beams,stress wave collectors,and scalers,as well as for impact testing of macro and micro materials and the design of sustainable plant-based materials for impact protection. 展开更多
关键词 Stress wave Variable cross-section Scaling effect Coconut fiber IMPACT
原文传递
Examining emotional intelligence of hospital-based nursing students with comparison between full-time and part-time study modes:A cross-sectional study
19
作者 Joanna Hiu Ki Ko Daniel Yee Tak Fong 《Nursing Communications》 2025年第17期1-6,共6页
association with academic and clinical performance.This study aimed to determine the EI level of hospital-based nursing students and examine differences between full-time and part-time students.Methods:We conducted a ... association with academic and clinical performance.This study aimed to determine the EI level of hospital-based nursing students and examine differences between full-time and part-time students.Methods:We conducted a cross-sectional study in a hospital-based nursing school.EI level was measured using the Schutte Self-report Emotional Intelligence Scale(SSEIS).Results:We recruited 287 participants(mean age:21.9 years).Their mean SSEIS score was 119.6(95%CI=118.57-120.65).The mean SSEIS scores of 172 full-time and 115 part-time nurses were 120.7(95%CI=119.3-122.0)and 118.1(95%CI=116.5-119.6),respectively.There was no significant difference between the groups.Conclusion:The EI difference between full-time and part-time nursing students was statistically insignificant.The need for further EI development among both full-time and part-time students must be addressed. 展开更多
关键词 emotional intelligence nursing education nursing students HOSPITAL-BASED FULL-TIME PART-TIME cross-sectional study
在线阅读 下载PDF
Parent interactions and physical aggression among Indonesian adolescents:a cross-sectional study
20
作者 Yoyok Bekti Pasetyo Alifya Az Zahra +5 位作者 Sri Sunaringsih Ika Wardojo Nur Melizza Anggraini Dwi Kurnia Nur Lailatul Masruroh Titih Huriah Rusnani Ab Latif 《Frontiers of Nursing》 2025年第3期345-354,共10页
Objective:This study aimed to examine the association between parent-child relationships and physically aggressive behavior among adolescents.Methods:This is a cross-sectional study that uses secondary data from the 2... Objective:This study aimed to examine the association between parent-child relationships and physically aggressive behavior among adolescents.Methods:This is a cross-sectional study that uses secondary data from the 2015 Indonesia Global School-Based Health Survey(IGSHS).Health surveys were conducted in 75 schools representing three regions(Sumatra,Java-Bali;Outer Sumatra;and Java-Bali)in 26 provinces and 68 districts/cities in Indonesia(N=10,139 students).Students who participated were aged 12-19 years,were enrolled in public schools in the junior and high school levels.Results:It has been seen that for most middle-aged adolescents(58.7%),their parents(25%-29%)pay less attention to academic assignments(homework),problems,and use of free time.The most significant factors that influence adolescents to commit violence are smoking and consuming alcohol.Adolescents who smoke are twice as likely to commit physical violence compared with adolescents who do not smoke(OR=2.005;95%CI=1.7062-2.396).Meanwhile,adolescents who consume alcohol are 1.8 times more likely to commit physical violence compared with adolescents who do not consume alcohol(OR=1.807;95%CI=1.421-2.298).Conclusions:Through educational activities and consultations,this study’s findings are valuable for establishing parenting programs among those concerned about their children’s aggressive behavior.Meanwhile,counseling programs can be started in schools by conducting self-detection of negative adolescent behavior,such as screening for smoking,alcohol consumption,sleep issues,and attempted suicide. 展开更多
关键词 parent-child relations adolescent behavior SMOKING alcohol drinking VIOLENCE cross-sectional studies Indonesia
暂未订购
上一页 1 2 250 下一页 到第
使用帮助 返回顶部