Objective Blood culture remains the gold standard for diagnosing bloodstream infections.Clinical laboratories must ensure the quality of blood culture processes from receipt to obtaining definitive results.We examined...Objective Blood culture remains the gold standard for diagnosing bloodstream infections.Clinical laboratories must ensure the quality of blood culture processes from receipt to obtaining definitive results.We examined laboratory analytical indicators associated with positive blood culture results.Methods Blood cultures collected from Peking Union Medical College Hospital between January 1,2020,and December 31,2022,were retrospectively analyzed.The mode of transportation(piping logistics delivery vs.staff),source of blood cultures(outpatient/emergency department vs.inpatient department),rotation of personnel,and time of reception(8:00–19:59 vs.20:00–07:59)were compared between blood culture-positive and-negative results.Results Between 2020 and 2022,the total positive rate of blood culture was 8.07%.The positive rate of blood cultures in the outpatient/emergency department was significantly higher than that in the inpatient department(12.46%vs.5.83%;P<0.0001).The time-to-detection of blood cultures was significantly affected by the delivery mode and personnel rotation.The blood culture positive rate of the total pre-analytical time within 1 h was significantly higher than that within 1–2 h or>2 h(P<0.0170).Conclusion Laboratory analytical indicators such as patient source,transportation mode,and personnel rotation significantly impacted the positive detection rate or time of blood culture.展开更多
Objective:To identify the root causes of typical adverse drug events through the lens of patient experiences proposing novel strategies to mitigate preventable harm.Methods:A qualitative case study leveraging in-depth...Objective:To identify the root causes of typical adverse drug events through the lens of patient experiences proposing novel strategies to mitigate preventable harm.Methods:A qualitative case study leveraging in-depth interviews with patients and families,anchored by Interactive Patient Par ticipation Theory,to analyze 4 high-severity adverse drug events(ADE)cases.Cases were purposively sampled from 8 communities in China's National Adverse Event Monitor Center(2018-2023).Semi-structured interviews explored patient perspectives,with data analyzed via thematic coding and triangulation against clinical records.Results:Five interconnected themes emerged:(1)erosion of trust,(2)communication breakdowns,(3)information asymmetry,(4)environmental inadequacies,and(5)technological alienation.Notably,75% of participants had≤high school education,and 50% used≥7 medications daily,compounding ADE risks.Conclusions:We considered elements mentioned by theory,exploring trust,communication,information,and suppor t as the root causes.In addition,we added“adaptability to new technology”as an impor tant and necessary component.It is impor tant and necessary to analyze typical adverse drug events from the perspectives of patients.展开更多
China ranked first worldwide in the production and export of electric bicycles.As an emerging market for electric bicycles,Malaysia holds significant potential for trade collabor ation with China in this sector.This s...China ranked first worldwide in the production and export of electric bicycles.As an emerging market for electric bicycles,Malaysia holds significant potential for trade collabor ation with China in this sector.This study presents a compar ative analysis of the national electric bicycle standards in China and Malaysia,offering technical insights from a standardization perspective.These insights aim to support Chinese enterprises in strategically positioning their technologies in the Malaysian market.The findings reveal significant differences in technical parameters,safety requirements,and testing methods,highlighting the need for tailored product adapt ation.展开更多
This paper investigates the teaching reform of the Program Comprehension and Analysis course in the context of industry-education integration and AI empowerment.To align with the evolving needs of the software industr...This paper investigates the teaching reform of the Program Comprehension and Analysis course in the context of industry-education integration and AI empowerment.To align with the evolving needs of the software industry,the course content has been updated to incorporate AI techniques such as large language models and deep learning.The reform enriches educational resources and introduces innovative instructional approaches.In addition,high-quality practical teaching cases have been developed,and immersive,hands-on learning experiences have been designed based on industrial platforms and real-world applications.These initiatives aim to enhance the practical skills and innovative thinking of professional degree graduate students,fostering high-caliber talent that aligns with industry demands.A survey of 90 graduate students revealed high levels of satisfaction regarding course content,teaching methodology,and skill development.The reform has proven effective in cultivating interdisciplinary professionals with solid foundations in software engineering and AI-driven innovation.展开更多
Mindfulness would enhance university students’emotional well-being and study engagement.However,the role of affect(positive and negative emotions)and psychological resources(psychological capital)linking mindfulness ...Mindfulness would enhance university students’emotional well-being and study engagement.However,the role of affect(positive and negative emotions)and psychological resources(psychological capital)linking mindfulness to study engagement remain underexplored.This cross-sectional study surveyed 688 Chinese university students(females=413,mean age=20.3,SD=0.83),using validated self-report measures of mindfulness,positive and negative emotions,psychological capital,and study engagement.Structural equation modeling and bias-corrected bootstrap analyses(5000 resamples)revealed that mindfulness directly enhanced positive emotions,psychological capital,and study engagement,while reducing negative emotions.Positive emotions partially mediated the positive effect of mindfulness on psychological capital and study engagement.Negative emotions partially and negatively mediated only the mindfulness-psychological capital link.Psychological capital independently mediated the mindfulness-engagement relationship,and two sequential mediation pathways emerged:(a)mindfulness→positive emotions→psychological capital→higher study engagement and(b)mindfulness→reduced negative emotions→psychological capital→higher study engagement.Consistent with broaden-and-build(B&B)theory and Conservation of Resources(COR)theory,these findings suggest that mindfulness fosters study engagement primarily by promoting positive emotional experiences and strengthening psychological capital.By implication,university student support programs should employ mindfulness-based interventions to cultivate emotional and psychological resources for higher students’engagement and overall well-being.展开更多
Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analyt...Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analytical solution to determine the longitudinal mechanical responses of tunnels subjected to the combined effects of seismic waves and strike-slip faulting.Adopting the elastic springbeam model,the seismic waves are modelled as shear horizontal(SH)waves and the fault dislocation follows an S-shaped pattern;the superposition principle for free-fielddisplacements caused by both effects is assumed.In addition,the transmission and reflectionof seismic waves at the fault-rock geological interface and the tangential contact conditions at the tunnel-rock interface are considered.The analytical model is validated against numerical simulations,confirmingits accuracy in calculating tunnel responses.Moreover,a parametric study is conducted to evaluate the impact of key factors,including fault displacement,fault zone width,fault dip angle,earthquake frequency,rock conditions,tunnel lining stiffness,and tangential contact conditions,on tunnel responses.Compared with each effect alone,the combined effects of seismic waves and strike-slip faulting significantlychange the tunnel deformation and internal forces,leading to increased tunnel responses,especially within the fault zone and near the fault-rock interfaces.Depending on specificparameters,tunnel responses can be classifiedinto seismic-dominated,faulting-dominated,and seismic-faulting coupled responses on the basis of the relative contributions of each effect.The proposed analytical solution can be applied to quickly predict the longitudinal mechanical behaviour of tunnels under such combined effects in engineering applications.展开更多
BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as exp...BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as expanding treatment indications,which affect the fair distribution of medical resources.There is limited research on ethical issues in the field of digestive endoscopy.AIM To investigate the level of ethical awareness among gastrointestinal endoscopy practitioners and analyze the ethical issues involved in gastrointestinal endoscopy technology.METHODS A questionnaire survey was performed to collect relevant data(gender,age,degree of education,professional title,personnel category,the level of understanding medical ethical principles,ethics training and its learning pathways)from gastrointestinal endoscopy practitioners at the Second Hospital of Dalian Medical University and Dalian Friendship Hospital,including licensed physicians and nurses(including trainees and graduate students).RESULTS The majority of gastrointestinal endoscopy practitioners have received training on ethics,but there is still considerable room for improvement in their ethical awareness.Different learning pathways may affect the mastery of ethical principles, and understanding of ethical principles is more easily achieved through hospital ethics institutions.CONCLUSIONTo address the ethical issues in gastrointestinal endoscopy technology, it is necessary to enhance the humanisticeducation of gastrointestinal endoscopy practitioners, incorporate ethical standards into the technology assessmentprocess, and establish a patient-centered diagnostic and treatment model to improve the ethical awareness of practitionersand achieve a balance between technology and ethics.展开更多
Does traditional Chinese economic thought possess genuine analytical rigor?This question lies at the heart of any serious evaluation of its theoretical value and historical significance.It also matters for understandi...Does traditional Chinese economic thought possess genuine analytical rigor?This question lies at the heart of any serious evaluation of its theoretical value and historical significance.It also matters for understanding how best to preserve,build on its remarkable achievements,and develop its intellectual legacy.Critics such as Schumpeter and Taylor have long argued that the economic reasoning found in ancient China cannot compare with that of classical Greece or medieval Europe.Yet this view often reflects the narrow assumptions of mainstream economics,defining analysis almost entirely in terms of market exchange.As a result,it tends to overlook traditions built around statecraft,governance,and the management of economic order.A careful re-examination and Sino-Western comparative analysis of key thinkers-including Mencius,Guanzi,and Sima Qian-tells a different story.Rooted in China’s distinctive cultural and philosophical heritage,traditional Chinese economic thought not only contains the analytical dimensions(as defined by Schumpeter)but also displays a broader and more diverse set of economic reasoning.Notably,its systematic depth and intellectual precision were,in many respects,remarkably advanced.Therefore,advancing the construction of a Chinese school of economics in the new era under the framework of the“Second Integration”,i.e.,integrating the basic tenets of Marxism with China’s fine traditional culture,should,and indeed can draw essential insights from this analytical tradition.展开更多
Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao)...Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao),wheat(Xiaomai),and jujube(Dazao),it functions to nourish the heart and calm the mind,harmonize the middle burner and regulate Qi,and alleviate urgency and restlessness.As its clinical application has expanded from traditional emotional disorders to neurological,endocrine,and various psychosomatic diseases,establishing a scientifically precise quality control system and deeply elucidating its pharmacodynamic material basis and mechanism of action have become critical tasks.Modern analytical methods,typified by chromatography,spectroscopy,and their hyphenated techniques,with their high sensitivity,high resolution,and powerful substance characterization capabilities,have become the core driving force for standardizing the quality control and modernizing the clinical application research of this formula.This paper systematically reviews the progress of the aforementioned analytical techniques and chemometrics in interpreting the chemical composition,establishing fingerprint profiles,controlling process quality,and researching the pharmacodynamic material basis of Ganmai Dazao Decoction.Furthermore,it discusses integrated approaches combining analytical techniques with pharmacology and clinical medicine to reveal mechanisms of action and explore therapeutic biomarkers.Finally,it provides an outlook on future directions and challenges,including technological integration and innovation,standardization of whole-process quality control systems,and evidence-based research aimed at internationalization.展开更多
Rotational computed laminography(CL)has broad application potential in three-dimensional imaging of plate-like objects because it only requires X-rays to pass through the tested object in the thickness direction durin...Rotational computed laminography(CL)has broad application potential in three-dimensional imaging of plate-like objects because it only requires X-rays to pass through the tested object in the thickness direction during the imaging process.In this study,a rectangular cross-section field-of-view rotational CL(RC-CL)is proposed for circuit board imaging.Compared to other rotational CL systems,the field of view is the largest and most suitable for rectangular circuit boards.Meanwhile,as the imaging geometry of RC-CL is significantly different from that of cone-beam CT,the Feldkamp-Davis-Kress(FDK)reconstruction algorithm cannot be used directly.However,transferring the projection data to fit into the CBCT geometry using two-dimensional interpolation introduces interpolation errors.Therefore,an FDK-type analytical reconstruction algorithm applicable to RC-CL was developed.The effectiveness of the method was validated through numerical experiments,and the influence of the tilt angle on the reconstruction results was analyzed.Finally,the RC-CL technique was applied to real defect detection research on circuit boards.展开更多
Objective Patients with atherosclerotic cardiovascular disease(ASCVD)following percutaneous coronary intervention(PCI)are classified as very-high-risk individuals in cardiovascular disease(CVD)risk stratification.The ...Objective Patients with atherosclerotic cardiovascular disease(ASCVD)following percutaneous coronary intervention(PCI)are classified as very-high-risk individuals in cardiovascular disease(CVD)risk stratification.The distribution pattern of traditional Chinese medicine(TCM)syndromes in this patient population,as well as its association with blood lipid profiles and clinical prognosis,remains unclear.The present prospective cohort study aims to investigate these correlations,thereby providing insights to enrich the research fields.Methods We enrolled consecutive patients with ASCVD who underwent PCI at the Integrated Cardiology Unit of China-Japan Friendship Hospital between September 1,2020 and December 31,2022.Demographics and clinical characteristics,signs and symptoms defining each TCM syndrome,and fasting venous blood samples were collected at baseline and follow up or upon major adverse cardiovascular events(MACEs).We analyzed the correlation between TCM syndromes,blood lipid profiles,and MACEs,and developed a new joint prognostic model incorporating both TCM syndromes and blood lipids using logistic regression.The analyses were based on detailed baseline and one-year follow-up data.Results A per-protocol analysis was performed on 586 patients with complete data ultimately.During the one-year follow-up,174 patients(29.69%)experienced a MACE.We performed statistical analyses on comorbidities,medication,and biochemical indicators across groups defined by TCM syndrome differentiation.When comparing different TCM syndromes,no significant differences were found in age,body mass index(BMI),history of revascularization,comorbidities,family history of CVD,smoking or drinking,or statin intensity(P>0.05).Patients with intertwined phlegm and blood stasis syndrome exhibited significantly higher levels of total cholesterol(TC,5.27±1.18 mmol/L,P<0.001),triglyceride(TG,1.96±1.33 mmol/L,P=0.008),low-density lipoprotein cholesterol(LDL-C,3.35±0.79 mmol/L,P<0.001),and high-density lipoprotein cholesterol(HDL-C,1.24±0.81 mmol/L,P<0.001)compared with those with other TCM syndromes combined.A multivariable logistic regression model was constructed to predict MACEs.The model included TCM syndrome type[with intertwined phlegm and blood stasis as a predictor,adjusted odds ratio(OR)=1.413,95%confidence interval(CI):0.517–3.864,P=0.501],age(adjusted OR=0.97,95%CI:0.955–1.001,P=0.057),male gender(adjusted OR=0.698,95%CI:0.416–1.170,P=0.173),TC(adjusted OR=1.004,95%CI:0.513–1.965,P=0.990),and LDL-C(adjusted OR=5.825,95%CI:2.214–15.326,P<0.001).This model demonstrated good discriminatory ability for MACEs in post-PCI ASCVD patients[the area under the receiver operating characteristic(ROC)curve(AUC)=0.865,95%CI:0.816–0.914].Conclusion The intertwined phlegm and blood stasis TCM syndrome is associated with a distinct atherogenic lipid profile characterized by elevated levels of TC and LDL-C.The prognostic model that incorporates this TCM syndrome type along with conventional lipid parameters(TC and LDL-C)shows good discriminatory ability for predicting MACEs in ASCVD patients after PCI,underscoring the potential clinical utility of integrating TCM syndrome differentiation into CVD risk assessment.展开更多
Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenn...Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenness with AMD,modification and mediation effect of air pollution,we conducted this prospective study.We con-structed weighted quantile sum(WQS)index as co-exposure to nitrogen oxides(NO_(x)),particulate matter<2.5μm(PM_(2.5)),particulate matter<10μm(PM10).Stratified Cox regression models were applied to test the effect of exposure.Effect modification of air pollution was assessed.Stratified Cox models through the indirect method and Aalen additive risk models were used in mediation analysis.Over median follow-up of 11.67 years,4596 AMD events were ascertained.Hazard ratios(HRs)and 95%confidence intervals(95%CIs)of incident AMD for pollution per interquartile range(IQR)increment were 1.10(1.04–1.16)for nitrogen dioxide(NO_(2)),1.09(1.03–1.15)for NO_(x),1.14(1.05–1.24)for PM_(2.5),1.13(1.05–1.21)for PM10.The HR(95%CI)of AMD associated with greenness 1000 m buffer per IQR increment was 0.91(0.86–0.97),300 m buffer was 0.94(0.89–0.99).The as-sociation between greenness 1000 m and AMD was 28.59%,44.77%,35.59%,32.31%and 27.08%mediated by the decreased WQS index,NO_(2),NO_(x),PM_(2.5) and PM10,respectively.Increased greenness was associated with lower AMD incidence,and air pollution partly mediate it,which implies that interventions aimed at improving air quality and increasing greenness could have a dual benefit in mitigating AMD risk.展开更多
Objective:To analyze factors affecting the utilization of human immunodeficiency virus counseling and testing(HCT)service among human immunodeficiency virus risk groups at Hessa Air Genting Health Center,Asahan Regenc...Objective:To analyze factors affecting the utilization of human immunodeficiency virus counseling and testing(HCT)service among human immunodeficiency virus risk groups at Hessa Air Genting Health Center,Asahan Regency,North Sumatera,Indonesia.Methods:This quantitative unmatched case-control study was conducted from April 2024 to April 2025 at Hessa Air Genting Health Center,Asahan Regency,North Sumatra Province,Indonesia.Female sex workers and men who have sex with men were selected using purposive sampling based on predefined inclusion and exclusion criteria.Data were collected via questionnaires and analyzed using SPSS version 18.0,with univariate analysis,bivariate analysis(Chi-square test),and multivariate analysis(logistic regression analysis).Results:Comprehensive analysis of 75 cases and 75 controls was conducted to identify factors affecting the utilization of HCT services.Specifically,this study identified significant effects of knowledge(OR 3.2,95%CI 1.5-7.0,P=0.003),perception(OR 5.6,95%CI 2.5-12.5,P<0.001),information media(OR 3.1,95%CI 1.4-6.8,P=0.005),and health workers encouragement(OR 4.0,95%CI 1.5-10.4,P=0.005).In contrast,access to health services did not have a significant effect.Conclusions:Knowledge,perception,information media,and health worker encouragement had significant effects on HCT service utilization,with perception identified as the dominant factor.To improve utilization,strengthening positive perceptions,targeted training for healthcare workers,strengthened partnerships with local non-governmental organizations,and the use of social media for health promotion are recommended.展开更多
Background:Despite highly effective vaccines against SARS-CoV-2,COVID-19 vaccine hesitancy persisted in some populations in England during the pandemic,with rates and motivations for hesitancy varying by demographic g...Background:Despite highly effective vaccines against SARS-CoV-2,COVID-19 vaccine hesitancy persisted in some populations in England during the pandemic,with rates and motivations for hesitancy varying by demographic group.Addressing the drivers of vaccine hesitancy through targeted interventions in hesitant groups is a public health priority for better and more rapid control of disease spread.We aimed to characterise the determinants and subtypes of vaccine hesitancy and identify more persistent forms of hesitancy via analysis of vaccine uptake in a large cross-sectional cohort with linked National Health Service(NHS)data.展开更多
Background:To determine whether initiating a glucagon-like peptide-1 receptor agonist(GLP-1 RA)within 3 months of type 2 diabetes(T2DM)diagnosis alters the subsequent risk of overall and site-specific cancer and wheth...Background:To determine whether initiating a glucagon-like peptide-1 receptor agonist(GLP-1 RA)within 3 months of type 2 diabetes(T2DM)diagnosis alters the subsequent risk of overall and site-specific cancer and whether this association differs by baseline body-mass index(BMI).Methods:This retrospective cohort study used electronic health records from the TriNetX U.S.research network.Adults aged 20 years or older diagnosed with T2DM between 2016 and 2024 were included if they received any hypoglycemic agents within 3 months before and after diagnosis.Following 1:1 propensity score matching,both the GLP-1 RA user and non-user groups included 183,264 patients.The study outcome was defined as a diagnosis of malignant neoplasms.Hazard ratios(HRs)for overall and site-specific cancer risk were estimated using Cox proportional hazards models.Kaplan–Meier analysis and stratified analysis by BMI were performed.Results:Early GLP-1 RA use demonstrated a modest but significant association with reduced overall cancer risk(HR 0.93;95%CI:0.90–0.96).Reduced risks were noted for cancers of the digestive(HR 0.81),respiratory(HR 0.66),and female genital(HR 0.87)systems.In stratified analysis,benefits were more pronounced in patients with BMI≥30,particularly for pancreatic and colorectal cancers.Conclusion:Early initiation of GLP-1 receptor agonists in patients with diagnosed T2DM was associated with a modest reduction in overall cancer risk,particularly among individuals with obesity.These findings highlight the dual metabolic and oncologic value of prompt GLP-1 RA therapy.展开更多
Fully grouted rock bolts have been used in mining industry for many years.Much research has been conducted to evaluate the load transfer behavior of fully grouted rock bolts with experimental programs.However,compared...Fully grouted rock bolts have been used in mining industry for many years.Much research has been conducted to evaluate the load transfer behavior of fully grouted rock bolts with experimental programs.However,compared with that,less work has been conducted with analytical modelling.Therefore,in this paper,the authors used an analytical model to study the load transfer behavior of fully grouted rock bolts.To confirm the credibility of this analytical model,an in-situ pull-out test was used to validate this model.There was a close match between the experimental result and the analytical result.Following it,a parametric study was conducted with this analytical model.The influence of coefficients,Young’s modulus of the rock bolt and the diameter of the rock bolt on the load transfer performance of rock bolts was studied.Furthermore,the load distribution along the fully grouted rock bolt was analytically studied.The results show that the axial load in the rock bolt decayed from the loaded end to the free end independent of the pull-out load.However,the trend of the load distribution curve was influenced by the pull-out load.This paper was beneficial for better understanding the load transfer mechanism of fully grouted rock bolts.展开更多
This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at ...This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at the downstream end of the penstock. Analytical formulas of maximum water hammer pressures at the downstream end of the tunnel and the valve were derived for a system subjected to linear and slow valve closure. The analytical results were then compared with numerical ones obtained using the method of characteristics. There is agreement between them. The formulas can be applied to estimating water hammer pressure at the valve and transmission of water hammer pressure through the surge chamber at the junction for a hydraulic pipe system with a surge chamber.展开更多
In this paper,an analytical model that represents the streamwise velocity distribution for open channel flow with submerged flexible vegetation is studied.In the present vegetated flow modelling,the whole flow field h...In this paper,an analytical model that represents the streamwise velocity distribution for open channel flow with submerged flexible vegetation is studied.In the present vegetated flow modelling,the whole flow field has been separated into two layers vertically: a vegetated layer and a non-vegetated free-water layer.Within the vegetated layer,an analysis of the mechanisms affecting water flow through flexible vegetation has been conducted.In the non-vegetated layer,a modified log-law equation that represents the velocity profile varying with vegetation height has been investigated.Based on the studied analytical model,a sensitivity analysis has been conducted to assess the influences of the drag (CD) and friction (Cf ) coefficients on the flow velocity.The investigated ranges of CD and Cf have also been compared to published values.The findings suggest that the CD and Cf values are non-constant at different depths and vegetation densities,unlike the constant values commonly suggested in literature.This phenomenon is particularly clear for flows with flexible vegetation,which is characterised by large deflection.展开更多
A closed-form out-of-plane dynamic displacement response of a curved track subjected to moving loads was proposed.The track structure was modeled as a planar curved Timoshenko beam periodically supported by the double...A closed-form out-of-plane dynamic displacement response of a curved track subjected to moving loads was proposed.The track structure was modeled as a planar curved Timoshenko beam periodically supported by the double-layer spring-damping elements.The general dynamic displacement response induced by the moving loads along the curve on the elastic semi-infinite space was firstly obtained in the frequency domain,according to the Duhamel integral and the dynamic reciprocity theorem.In the case of the periodic curved track structure subjected to moving loads,the dynamic displacement equation was simplified into a form of summation within the basic track cell instead of the integral.The transfer function for the curved track was expressed in the form of a transfer matrix.Single and series moving loads were involved in the calculation program.For the verification of the analytical model,the mid-span vertical deflection of a simply support curved beam subjected to moving load was recalculated and compared with the same case in the reference.The research results indicate that:under the same moving loads,the displacement response of the curved track decreases slightly with the increasing track radius,and the displacement response of the curved track with the radius greater than or equal to 600 m is almost equivalent to the displacement response of the straight track;the frequency spectrum of the curved track is more abundant than that of the straight track,which may result in more wheel-rail resonance and rail corrugation in the curved lines.展开更多
The homogeneous balance method was improved and applied to two systems Of nonlinear evolution equations. As a result, several families of exact analytic solutions are derived by some new ansatzs. These solutions conta...The homogeneous balance method was improved and applied to two systems Of nonlinear evolution equations. As a result, several families of exact analytic solutions are derived by some new ansatzs. These solutions contain Wang's and Zhang's results and other new types of analytical solutions, such as rational fraction solutions and periodic solutions. The way can also be applied to solve more nonlinear partial differential equations.展开更多
基金supported by grants from the National High Level Hospital Clinical Research Funding(2022-PUMCH-B-074)Peking Union Medical College Hospital Research Funding for Postdoc(kyfyjj202320).
文摘Objective Blood culture remains the gold standard for diagnosing bloodstream infections.Clinical laboratories must ensure the quality of blood culture processes from receipt to obtaining definitive results.We examined laboratory analytical indicators associated with positive blood culture results.Methods Blood cultures collected from Peking Union Medical College Hospital between January 1,2020,and December 31,2022,were retrospectively analyzed.The mode of transportation(piping logistics delivery vs.staff),source of blood cultures(outpatient/emergency department vs.inpatient department),rotation of personnel,and time of reception(8:00–19:59 vs.20:00–07:59)were compared between blood culture-positive and-negative results.Results Between 2020 and 2022,the total positive rate of blood culture was 8.07%.The positive rate of blood cultures in the outpatient/emergency department was significantly higher than that in the inpatient department(12.46%vs.5.83%;P<0.0001).The time-to-detection of blood cultures was significantly affected by the delivery mode and personnel rotation.The blood culture positive rate of the total pre-analytical time within 1 h was significantly higher than that within 1–2 h or>2 h(P<0.0170).Conclusion Laboratory analytical indicators such as patient source,transportation mode,and personnel rotation significantly impacted the positive detection rate or time of blood culture.
基金supported by the Science and Technology Fund Project of Guizhou Health Commission(gzwkj2025-163)。
文摘Objective:To identify the root causes of typical adverse drug events through the lens of patient experiences proposing novel strategies to mitigate preventable harm.Methods:A qualitative case study leveraging in-depth interviews with patients and families,anchored by Interactive Patient Par ticipation Theory,to analyze 4 high-severity adverse drug events(ADE)cases.Cases were purposively sampled from 8 communities in China's National Adverse Event Monitor Center(2018-2023).Semi-structured interviews explored patient perspectives,with data analyzed via thematic coding and triangulation against clinical records.Results:Five interconnected themes emerged:(1)erosion of trust,(2)communication breakdowns,(3)information asymmetry,(4)environmental inadequacies,and(5)technological alienation.Notably,75% of participants had≤high school education,and 50% used≥7 medications daily,compounding ADE risks.Conclusions:We considered elements mentioned by theory,exploring trust,communication,information,and suppor t as the root causes.In addition,we added“adaptability to new technology”as an impor tant and necessary component.It is impor tant and necessary to analyze typical adverse drug events from the perspectives of patients.
文摘China ranked first worldwide in the production and export of electric bicycles.As an emerging market for electric bicycles,Malaysia holds significant potential for trade collabor ation with China in this sector.This study presents a compar ative analysis of the national electric bicycle standards in China and Malaysia,offering technical insights from a standardization perspective.These insights aim to support Chinese enterprises in strategically positioning their technologies in the Malaysian market.The findings reveal significant differences in technical parameters,safety requirements,and testing methods,highlighting the need for tailored product adapt ation.
基金supported by Project of Higher Education Teaching Reform Research in Heilongjiang Province(Graduate Education)(Grant No.SJGYY2024030).
文摘This paper investigates the teaching reform of the Program Comprehension and Analysis course in the context of industry-education integration and AI empowerment.To align with the evolving needs of the software industry,the course content has been updated to incorporate AI techniques such as large language models and deep learning.The reform enriches educational resources and introduces innovative instructional approaches.In addition,high-quality practical teaching cases have been developed,and immersive,hands-on learning experiences have been designed based on industrial platforms and real-world applications.These initiatives aim to enhance the practical skills and innovative thinking of professional degree graduate students,fostering high-caliber talent that aligns with industry demands.A survey of 90 graduate students revealed high levels of satisfaction regarding course content,teaching methodology,and skill development.The reform has proven effective in cultivating interdisciplinary professionals with solid foundations in software engineering and AI-driven innovation.
文摘Mindfulness would enhance university students’emotional well-being and study engagement.However,the role of affect(positive and negative emotions)and psychological resources(psychological capital)linking mindfulness to study engagement remain underexplored.This cross-sectional study surveyed 688 Chinese university students(females=413,mean age=20.3,SD=0.83),using validated self-report measures of mindfulness,positive and negative emotions,psychological capital,and study engagement.Structural equation modeling and bias-corrected bootstrap analyses(5000 resamples)revealed that mindfulness directly enhanced positive emotions,psychological capital,and study engagement,while reducing negative emotions.Positive emotions partially mediated the positive effect of mindfulness on psychological capital and study engagement.Negative emotions partially and negatively mediated only the mindfulness-psychological capital link.Psychological capital independently mediated the mindfulness-engagement relationship,and two sequential mediation pathways emerged:(a)mindfulness→positive emotions→psychological capital→higher study engagement and(b)mindfulness→reduced negative emotions→psychological capital→higher study engagement.Consistent with broaden-and-build(B&B)theory and Conservation of Resources(COR)theory,these findings suggest that mindfulness fosters study engagement primarily by promoting positive emotional experiences and strengthening psychological capital.By implication,university student support programs should employ mindfulness-based interventions to cultivate emotional and psychological resources for higher students’engagement and overall well-being.
基金supported by the National Natural Science Foundation of China(No.41941018)Shanghai Gaofeng Discipline Construction Funding.
文摘Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analytical solution to determine the longitudinal mechanical responses of tunnels subjected to the combined effects of seismic waves and strike-slip faulting.Adopting the elastic springbeam model,the seismic waves are modelled as shear horizontal(SH)waves and the fault dislocation follows an S-shaped pattern;the superposition principle for free-fielddisplacements caused by both effects is assumed.In addition,the transmission and reflectionof seismic waves at the fault-rock geological interface and the tangential contact conditions at the tunnel-rock interface are considered.The analytical model is validated against numerical simulations,confirmingits accuracy in calculating tunnel responses.Moreover,a parametric study is conducted to evaluate the impact of key factors,including fault displacement,fault zone width,fault dip angle,earthquake frequency,rock conditions,tunnel lining stiffness,and tangential contact conditions,on tunnel responses.Compared with each effect alone,the combined effects of seismic waves and strike-slip faulting significantlychange the tunnel deformation and internal forces,leading to increased tunnel responses,especially within the fault zone and near the fault-rock interfaces.Depending on specificparameters,tunnel responses can be classifiedinto seismic-dominated,faulting-dominated,and seismic-faulting coupled responses on the basis of the relative contributions of each effect.The proposed analytical solution can be applied to quickly predict the longitudinal mechanical behaviour of tunnels under such combined effects in engineering applications.
文摘BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as expanding treatment indications,which affect the fair distribution of medical resources.There is limited research on ethical issues in the field of digestive endoscopy.AIM To investigate the level of ethical awareness among gastrointestinal endoscopy practitioners and analyze the ethical issues involved in gastrointestinal endoscopy technology.METHODS A questionnaire survey was performed to collect relevant data(gender,age,degree of education,professional title,personnel category,the level of understanding medical ethical principles,ethics training and its learning pathways)from gastrointestinal endoscopy practitioners at the Second Hospital of Dalian Medical University and Dalian Friendship Hospital,including licensed physicians and nurses(including trainees and graduate students).RESULTS The majority of gastrointestinal endoscopy practitioners have received training on ethics,but there is still considerable room for improvement in their ethical awareness.Different learning pathways may affect the mastery of ethical principles, and understanding of ethical principles is more easily achieved through hospital ethics institutions.CONCLUSIONTo address the ethical issues in gastrointestinal endoscopy technology, it is necessary to enhance the humanisticeducation of gastrointestinal endoscopy practitioners, incorporate ethical standards into the technology assessmentprocess, and establish a patient-centered diagnostic and treatment model to improve the ethical awareness of practitionersand achieve a balance between technology and ethics.
基金supported by the National Social Science Fund of China(NSSFC):NSSFC Major Project“Exploration and Practice in the Development of Chinese Economics Since the Modern Era”(Grant No.17ZDA034)NSSFC Key Project“The Status and Value of Traditional Chinese Economic Thought”(Grant No.17AJL006)NSSFC General Project“The Transformation and Evolution of Chinese Economic Thought During the Republican Era”(Grant No.22BJL130).
文摘Does traditional Chinese economic thought possess genuine analytical rigor?This question lies at the heart of any serious evaluation of its theoretical value and historical significance.It also matters for understanding how best to preserve,build on its remarkable achievements,and develop its intellectual legacy.Critics such as Schumpeter and Taylor have long argued that the economic reasoning found in ancient China cannot compare with that of classical Greece or medieval Europe.Yet this view often reflects the narrow assumptions of mainstream economics,defining analysis almost entirely in terms of market exchange.As a result,it tends to overlook traditions built around statecraft,governance,and the management of economic order.A careful re-examination and Sino-Western comparative analysis of key thinkers-including Mencius,Guanzi,and Sima Qian-tells a different story.Rooted in China’s distinctive cultural and philosophical heritage,traditional Chinese economic thought not only contains the analytical dimensions(as defined by Schumpeter)but also displays a broader and more diverse set of economic reasoning.Notably,its systematic depth and intellectual precision were,in many respects,remarkably advanced.Therefore,advancing the construction of a Chinese school of economics in the new era under the framework of the“Second Integration”,i.e.,integrating the basic tenets of Marxism with China’s fine traditional culture,should,and indeed can draw essential insights from this analytical tradition.
文摘Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao),wheat(Xiaomai),and jujube(Dazao),it functions to nourish the heart and calm the mind,harmonize the middle burner and regulate Qi,and alleviate urgency and restlessness.As its clinical application has expanded from traditional emotional disorders to neurological,endocrine,and various psychosomatic diseases,establishing a scientifically precise quality control system and deeply elucidating its pharmacodynamic material basis and mechanism of action have become critical tasks.Modern analytical methods,typified by chromatography,spectroscopy,and their hyphenated techniques,with their high sensitivity,high resolution,and powerful substance characterization capabilities,have become the core driving force for standardizing the quality control and modernizing the clinical application research of this formula.This paper systematically reviews the progress of the aforementioned analytical techniques and chemometrics in interpreting the chemical composition,establishing fingerprint profiles,controlling process quality,and researching the pharmacodynamic material basis of Ganmai Dazao Decoction.Furthermore,it discusses integrated approaches combining analytical techniques with pharmacology and clinical medicine to reveal mechanisms of action and explore therapeutic biomarkers.Finally,it provides an outlook on future directions and challenges,including technological integration and innovation,standardization of whole-process quality control systems,and evidence-based research aimed at internationalization.
基金supported by the National Key Research and Development Program of China(No.2022YFF0607802)。
文摘Rotational computed laminography(CL)has broad application potential in three-dimensional imaging of plate-like objects because it only requires X-rays to pass through the tested object in the thickness direction during the imaging process.In this study,a rectangular cross-section field-of-view rotational CL(RC-CL)is proposed for circuit board imaging.Compared to other rotational CL systems,the field of view is the largest and most suitable for rectangular circuit boards.Meanwhile,as the imaging geometry of RC-CL is significantly different from that of cone-beam CT,the Feldkamp-Davis-Kress(FDK)reconstruction algorithm cannot be used directly.However,transferring the projection data to fit into the CBCT geometry using two-dimensional interpolation introduces interpolation errors.Therefore,an FDK-type analytical reconstruction algorithm applicable to RC-CL was developed.The effectiveness of the method was validated through numerical experiments,and the influence of the tilt angle on the reconstruction results was analyzed.Finally,the RC-CL technique was applied to real defect detection research on circuit boards.
基金Capital Health Development Scientific Research Project(2020-2-4064)National Key Research and Development Program of China(2018YFC2002502).
文摘Objective Patients with atherosclerotic cardiovascular disease(ASCVD)following percutaneous coronary intervention(PCI)are classified as very-high-risk individuals in cardiovascular disease(CVD)risk stratification.The distribution pattern of traditional Chinese medicine(TCM)syndromes in this patient population,as well as its association with blood lipid profiles and clinical prognosis,remains unclear.The present prospective cohort study aims to investigate these correlations,thereby providing insights to enrich the research fields.Methods We enrolled consecutive patients with ASCVD who underwent PCI at the Integrated Cardiology Unit of China-Japan Friendship Hospital between September 1,2020 and December 31,2022.Demographics and clinical characteristics,signs and symptoms defining each TCM syndrome,and fasting venous blood samples were collected at baseline and follow up or upon major adverse cardiovascular events(MACEs).We analyzed the correlation between TCM syndromes,blood lipid profiles,and MACEs,and developed a new joint prognostic model incorporating both TCM syndromes and blood lipids using logistic regression.The analyses were based on detailed baseline and one-year follow-up data.Results A per-protocol analysis was performed on 586 patients with complete data ultimately.During the one-year follow-up,174 patients(29.69%)experienced a MACE.We performed statistical analyses on comorbidities,medication,and biochemical indicators across groups defined by TCM syndrome differentiation.When comparing different TCM syndromes,no significant differences were found in age,body mass index(BMI),history of revascularization,comorbidities,family history of CVD,smoking or drinking,or statin intensity(P>0.05).Patients with intertwined phlegm and blood stasis syndrome exhibited significantly higher levels of total cholesterol(TC,5.27±1.18 mmol/L,P<0.001),triglyceride(TG,1.96±1.33 mmol/L,P=0.008),low-density lipoprotein cholesterol(LDL-C,3.35±0.79 mmol/L,P<0.001),and high-density lipoprotein cholesterol(HDL-C,1.24±0.81 mmol/L,P<0.001)compared with those with other TCM syndromes combined.A multivariable logistic regression model was constructed to predict MACEs.The model included TCM syndrome type[with intertwined phlegm and blood stasis as a predictor,adjusted odds ratio(OR)=1.413,95%confidence interval(CI):0.517–3.864,P=0.501],age(adjusted OR=0.97,95%CI:0.955–1.001,P=0.057),male gender(adjusted OR=0.698,95%CI:0.416–1.170,P=0.173),TC(adjusted OR=1.004,95%CI:0.513–1.965,P=0.990),and LDL-C(adjusted OR=5.825,95%CI:2.214–15.326,P<0.001).This model demonstrated good discriminatory ability for MACEs in post-PCI ASCVD patients[the area under the receiver operating characteristic(ROC)curve(AUC)=0.865,95%CI:0.816–0.914].Conclusion The intertwined phlegm and blood stasis TCM syndrome is associated with a distinct atherogenic lipid profile characterized by elevated levels of TC and LDL-C.The prognostic model that incorporates this TCM syndrome type along with conventional lipid parameters(TC and LDL-C)shows good discriminatory ability for predicting MACEs in ASCVD patients after PCI,underscoring the potential clinical utility of integrating TCM syndrome differentiation into CVD risk assessment.
基金supported by the High-level Talents Introduction Plan from Central South University(No.502045003)the National Natural Science Foundation of China(No.42277438)Hunan Provincial Natural Science Foundation for Distinguished Young Scholars(No.2024JJ2082)to Fang Xiao,and the Postgraduate Independent Exploration and Innovation Project of Central South University,China(Nos.2024ZZTS0557 and 2023ZZTS0993)。
文摘Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenness with AMD,modification and mediation effect of air pollution,we conducted this prospective study.We con-structed weighted quantile sum(WQS)index as co-exposure to nitrogen oxides(NO_(x)),particulate matter<2.5μm(PM_(2.5)),particulate matter<10μm(PM10).Stratified Cox regression models were applied to test the effect of exposure.Effect modification of air pollution was assessed.Stratified Cox models through the indirect method and Aalen additive risk models were used in mediation analysis.Over median follow-up of 11.67 years,4596 AMD events were ascertained.Hazard ratios(HRs)and 95%confidence intervals(95%CIs)of incident AMD for pollution per interquartile range(IQR)increment were 1.10(1.04–1.16)for nitrogen dioxide(NO_(2)),1.09(1.03–1.15)for NO_(x),1.14(1.05–1.24)for PM_(2.5),1.13(1.05–1.21)for PM10.The HR(95%CI)of AMD associated with greenness 1000 m buffer per IQR increment was 0.91(0.86–0.97),300 m buffer was 0.94(0.89–0.99).The as-sociation between greenness 1000 m and AMD was 28.59%,44.77%,35.59%,32.31%and 27.08%mediated by the decreased WQS index,NO_(2),NO_(x),PM_(2.5) and PM10,respectively.Increased greenness was associated with lower AMD incidence,and air pollution partly mediate it,which implies that interventions aimed at improving air quality and increasing greenness could have a dual benefit in mitigating AMD risk.
文摘Objective:To analyze factors affecting the utilization of human immunodeficiency virus counseling and testing(HCT)service among human immunodeficiency virus risk groups at Hessa Air Genting Health Center,Asahan Regency,North Sumatera,Indonesia.Methods:This quantitative unmatched case-control study was conducted from April 2024 to April 2025 at Hessa Air Genting Health Center,Asahan Regency,North Sumatra Province,Indonesia.Female sex workers and men who have sex with men were selected using purposive sampling based on predefined inclusion and exclusion criteria.Data were collected via questionnaires and analyzed using SPSS version 18.0,with univariate analysis,bivariate analysis(Chi-square test),and multivariate analysis(logistic regression analysis).Results:Comprehensive analysis of 75 cases and 75 controls was conducted to identify factors affecting the utilization of HCT services.Specifically,this study identified significant effects of knowledge(OR 3.2,95%CI 1.5-7.0,P=0.003),perception(OR 5.6,95%CI 2.5-12.5,P<0.001),information media(OR 3.1,95%CI 1.4-6.8,P=0.005),and health workers encouragement(OR 4.0,95%CI 1.5-10.4,P=0.005).In contrast,access to health services did not have a significant effect.Conclusions:Knowledge,perception,information media,and health worker encouragement had significant effects on HCT service utilization,with perception identified as the dominant factor.To improve utilization,strengthening positive perceptions,targeted training for healthcare workers,strengthened partnerships with local non-governmental organizations,and the use of social media for health promotion are recommended.
文摘Background:Despite highly effective vaccines against SARS-CoV-2,COVID-19 vaccine hesitancy persisted in some populations in England during the pandemic,with rates and motivations for hesitancy varying by demographic group.Addressing the drivers of vaccine hesitancy through targeted interventions in hesitant groups is a public health priority for better and more rapid control of disease spread.We aimed to characterise the determinants and subtypes of vaccine hesitancy and identify more persistent forms of hesitancy via analysis of vaccine uptake in a large cross-sectional cohort with linked National Health Service(NHS)data.
基金financial support fromthe Chung Shan Medical University Hospital,Taiwan(CSH-2022-A-009).
文摘Background:To determine whether initiating a glucagon-like peptide-1 receptor agonist(GLP-1 RA)within 3 months of type 2 diabetes(T2DM)diagnosis alters the subsequent risk of overall and site-specific cancer and whether this association differs by baseline body-mass index(BMI).Methods:This retrospective cohort study used electronic health records from the TriNetX U.S.research network.Adults aged 20 years or older diagnosed with T2DM between 2016 and 2024 were included if they received any hypoglycemic agents within 3 months before and after diagnosis.Following 1:1 propensity score matching,both the GLP-1 RA user and non-user groups included 183,264 patients.The study outcome was defined as a diagnosis of malignant neoplasms.Hazard ratios(HRs)for overall and site-specific cancer risk were estimated using Cox proportional hazards models.Kaplan–Meier analysis and stratified analysis by BMI were performed.Results:Early GLP-1 RA use demonstrated a modest but significant association with reduced overall cancer risk(HR 0.93;95%CI:0.90–0.96).Reduced risks were noted for cancers of the digestive(HR 0.81),respiratory(HR 0.66),and female genital(HR 0.87)systems.In stratified analysis,benefits were more pronounced in patients with BMI≥30,particularly for pancreatic and colorectal cancers.Conclusion:Early initiation of GLP-1 receptor agonists in patients with diagnosed T2DM was associated with a modest reduction in overall cancer risk,particularly among individuals with obesity.These findings highlight the dual metabolic and oncologic value of prompt GLP-1 RA therapy.
基金supported by the National Natural Science Foundation of China (Nos. 51574243 and 51904302)the Yue Qi Distinguished Scholar Project of China (No. 800015Z1138)+1 种基金China University of Mining and Technology, Beijingthe Fundamental Research Funds for the Central Universities, China (No.800015J6)。
文摘Fully grouted rock bolts have been used in mining industry for many years.Much research has been conducted to evaluate the load transfer behavior of fully grouted rock bolts with experimental programs.However,compared with that,less work has been conducted with analytical modelling.Therefore,in this paper,the authors used an analytical model to study the load transfer behavior of fully grouted rock bolts.To confirm the credibility of this analytical model,an in-situ pull-out test was used to validate this model.There was a close match between the experimental result and the analytical result.Following it,a parametric study was conducted with this analytical model.The influence of coefficients,Young’s modulus of the rock bolt and the diameter of the rock bolt on the load transfer performance of rock bolts was studied.Furthermore,the load distribution along the fully grouted rock bolt was analytically studied.The results show that the axial load in the rock bolt decayed from the loaded end to the free end independent of the pull-out load.However,the trend of the load distribution curve was influenced by the pull-out load.This paper was beneficial for better understanding the load transfer mechanism of fully grouted rock bolts.
基金supported by the National Natural Science Foundation of China (Grant No.50539070)the Major State Basic Research Development Program of China (Grant No.2006CB403304)
文摘This paper presents an analytical investigation of water hammer in a hydraulic pressurized pipe system with a throttled surge chamber located at the junction between a tunnel and a penstock, and a valve positioned at the downstream end of the penstock. Analytical formulas of maximum water hammer pressures at the downstream end of the tunnel and the valve were derived for a system subjected to linear and slow valve closure. The analytical results were then compared with numerical ones obtained using the method of characteristics. There is agreement between them. The formulas can be applied to estimating water hammer pressure at the valve and transmission of water hammer pressure through the surge chamber at the junction for a hydraulic pipe system with a surge chamber.
文摘In this paper,an analytical model that represents the streamwise velocity distribution for open channel flow with submerged flexible vegetation is studied.In the present vegetated flow modelling,the whole flow field has been separated into two layers vertically: a vegetated layer and a non-vegetated free-water layer.Within the vegetated layer,an analysis of the mechanisms affecting water flow through flexible vegetation has been conducted.In the non-vegetated layer,a modified log-law equation that represents the velocity profile varying with vegetation height has been investigated.Based on the studied analytical model,a sensitivity analysis has been conducted to assess the influences of the drag (CD) and friction (Cf ) coefficients on the flow velocity.The investigated ranges of CD and Cf have also been compared to published values.The findings suggest that the CD and Cf values are non-constant at different depths and vegetation densities,unlike the constant values commonly suggested in literature.This phenomenon is particularly clear for flows with flexible vegetation,which is characterised by large deflection.
基金Project supported by the National Natural Science Foundation of China(Nos.51008017 and 51378001)the Research Fund for Beijing Postdoctoral Work,and the Innovation Fund for PhD of Beijing Jiaotong University(No.2011YJS261),China
文摘A closed-form out-of-plane dynamic displacement response of a curved track subjected to moving loads was proposed.The track structure was modeled as a planar curved Timoshenko beam periodically supported by the double-layer spring-damping elements.The general dynamic displacement response induced by the moving loads along the curve on the elastic semi-infinite space was firstly obtained in the frequency domain,according to the Duhamel integral and the dynamic reciprocity theorem.In the case of the periodic curved track structure subjected to moving loads,the dynamic displacement equation was simplified into a form of summation within the basic track cell instead of the integral.The transfer function for the curved track was expressed in the form of a transfer matrix.Single and series moving loads were involved in the calculation program.For the verification of the analytical model,the mid-span vertical deflection of a simply support curved beam subjected to moving load was recalculated and compared with the same case in the reference.The research results indicate that:under the same moving loads,the displacement response of the curved track decreases slightly with the increasing track radius,and the displacement response of the curved track with the radius greater than or equal to 600 m is almost equivalent to the displacement response of the straight track;the frequency spectrum of the curved track is more abundant than that of the straight track,which may result in more wheel-rail resonance and rail corrugation in the curved lines.
文摘The homogeneous balance method was improved and applied to two systems Of nonlinear evolution equations. As a result, several families of exact analytic solutions are derived by some new ansatzs. These solutions contain Wang's and Zhang's results and other new types of analytical solutions, such as rational fraction solutions and periodic solutions. The way can also be applied to solve more nonlinear partial differential equations.
