期刊文献+
共找到4,773篇文章
< 1 2 239 >
每页显示 20 50 100
ZTE Positioned in the Leaders Quadrant in Leading Industry Analyst Firm Report
1
作者 ZTE Corporation 《ZTE Communications》 2010年第3期41-41,共1页
ZTE Corporation announced on July 14, 2010 that it has been positioned in the leaders quadrant in Gartner's Magic Quadrant for Softswitch Architecture Report.
关键词 ZTE positioned in the Leaders Quadrant in Leading Industry Analyst Firm Report IMS
在线阅读 下载PDF
Mutual Inductance Calculation Between Arbitrarily Positioned Polygonal Coils 被引量:1
2
作者 ZHANG Zijian SHAO Ming +5 位作者 SHANG Kai LI Xuekong HUANG Chunliang SHI Jinku CUI Huaxian DONG Yangyang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第S01期120-126,共7页
Polygonal coil systems are designed for increasing and more kinds of sensors and electromagnetic systems.This paper presents a method for calculating mutual inductance between polygonal coils including irregular polyg... Polygonal coil systems are designed for increasing and more kinds of sensors and electromagnetic systems.This paper presents a method for calculating mutual inductance between polygonal coils including irregular polygons.Based on the Biot-Savart law,the method calculates mutual inductance by dividing a polygonal coil into finite wires,and expresses the magnetic induction intensity generated by the excitation coil as a function of the spatial position of each vertex of the coil.The calculation method of the feasible region of the objective function is updated and the calculation process is simplified,so the calculation accuracy is improved.For octagon coils arbitrarily positioned in space,the accuracy of the algorithm is verified by the simulation and experiment. 展开更多
关键词 mutual inductance polygonal coils Biot-Savart law arbitrary position
在线阅读 下载PDF
基于改进Wallace树的Posit乘法单元优化
3
作者 高志勇 王磊 +2 位作者 刘博文 英津瑞 王盼龙 《计算机工程》 北大核心 2026年第3期276-286,共11页
Posit格式作为一种新的浮点数表示方法,虽然在动态范围和舍入误差处理上相比IEEE 754浮点格式具有显著优势,但其硬件实现尤其是尾数乘法器的设计存在挑战。为此,通过增加特定的计数器、重新设计部分积求和阶段计数器布局以及改进最终求... Posit格式作为一种新的浮点数表示方法,虽然在动态范围和舍入误差处理上相比IEEE 754浮点格式具有显著优势,但其硬件实现尤其是尾数乘法器的设计存在挑战。为此,通过增加特定的计数器、重新设计部分积求和阶段计数器布局以及改进最终求和阶段使用的加法器,提出一种名为3L-Wallace树的改进Wallace树算法,以减少部分积求和的阶段数,降低硬件资源消耗和整体延迟。随后,基于3L-Wallace树对Posit乘法单元进行了优化。此外,还引入模块化设计方法,将大位宽乘法器划分为更易于实现的小模块,简化了设计过程并减小了实现难度。同时,设计一种动态选择算法,根据运行时尾数位宽动态选择合适位宽的乘法器,避免硬件资源浪费。实验结果显示,3L-Wallace树算法硬件资源消耗相较于传统方法平均减少约9.5%,功率平均降低约8.1%,时延平均降低约10.4%,整体表现优于传统方法,特别是在大位宽乘法器的实现上表现突出。 展开更多
关键词 Posit格式 WALLACE树 乘法单元 尾数乘法器 计数器 现场可编程门阵列
在线阅读 下载PDF
A New Inversion-free Iterative Method for Solving the Nonlinear Matrix Equation and Its Application in Optimal Control
4
作者 GAO Xiangyu XIE Weiwei ZHANG Lina 《应用数学》 北大核心 2026年第1期143-150,共8页
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ... In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method. 展开更多
关键词 Nonlinear matrix equation Maximal positive definite solution Inversion-free iterative method Optimal control
在线阅读 下载PDF
Association between Positive Solitude and Psychological Adaptation of International Students in China:The Intermediary Roles of Authenticity and Loneliness
5
作者 Hong Zou Hanwei Wu +2 位作者 Haidi Wu Ningyao Yu Zhiguang Fan 《International Journal of Mental Health Promotion》 2026年第3期163-182,共20页
Objective:International students frequently face psychological adaptation difficulties while studying and living abroad.As an effective psychological resource,positive solitude has been identified as a potential facto... Objective:International students frequently face psychological adaptation difficulties while studying and living abroad.As an effective psychological resource,positive solitude has been identified as a potential factor for improving psychological well-being,but the underlying mechanism linking the two has not been fully explored.The current study aims to explore the relationship between positive solitude and psychological adaptation of international students,with particular emphasis on the intermediary roles of authenticity and loneliness.Methods:A total of 529 international tertiary students(Mage=23.76,SD=5.08;60.68%male)were surveyed using the Positive Solitude Scale(PSS),Authenticity Scale(AS),6-item UCLA Loneliness Scale(ULS-6),and Brief Psychological Adaptation Scale(BPAS).SPSS27.0 was used for descriptive statistical analysis and Pearson correlation analysis.PROCESS macro(Model 6)was employed to test a serial mediation model,in which authenticity and loneliness function as intermediary variables between positive solitude and psychological adaptation.Results:The correlation analysis indicated significant associations among positive solitude,authenticity,loneliness,and psychological adaptation(r=−0.544~0.511).Positive solitude was directly and positively related to psychological adaptation(β=0.132,t=3.609,p<0.001)and indirectly related to psychological adaptation through two pathways:a single mediation via authenticity(indirect effect=0.089)and a serial mediation through authenticity and loneliness(indirect effect=0.062).Loneliness did not serve as a significant mediator(indirect effect=–0.015,95%CI[–0.049,0.019]).The total indirect effect was 0.136.Conclusions:Interventions targeting international students’capacity for experiencing positive solitude and authenticity can help to reduce loneliness and increase psychological adaptation.The findings derived from this study are conducive to understanding the relationship between positive solitude and psychological adaptation,as well as its underlying mechanisms.In addition,the study offers a new perspective for educational management and psychological counseling services for international students. 展开更多
关键词 International students positive solitude AUTHENTICITY psychological adaptation LONELINESS
在线阅读 下载PDF
Machine learning combined with the PMF model reveals the sources and driving factors of PAHs and Cl-PAHs in urban runoff
6
作者 Li Li Hai Huang +5 位作者 Pei Hua Tao Chen Jin Zhang Peng Deng Zongxi Zhao Bo Yan 《Journal of Environmental Sciences》 2026年第2期174-184,共11页
Urban rainwater runoff is an important source of nonpoint source pollution due to its transport of diverse contaminants,including polycyclic aromatic hydrocarbons(PAHs)and chlorinated derivatives.Importantly,these chl... Urban rainwater runoff is an important source of nonpoint source pollution due to its transport of diverse contaminants,including polycyclic aromatic hydrocarbons(PAHs)and chlorinated derivatives.Importantly,these chlorinated polycyclic aromatic hydrocarbons(Cl-PAHs)exhibit elevated toxicological potential compared to their non-halogenated parent compounds.In this study,we proposed an approach that combined multivariate receptor model with integration of SHapley Additive exPlanations and Random Forest model.This method identifies the possible sources and reveals the impact of source apportionment results and environmental driving factors(such as geographical and meteorological data)on pollutant concentrations.Sixteen PAHs and nine ClPAHs were detected in 79 runoff samples from all three sites.TheΣ_(16)PAHs average concentration(2923.93 to 6071.83 ng/L)was significantly higher than theΣ_(9)Cl-PAHs(384.34 to 1314.73 ng/L).The source apportionment was conducted by positive matrix factorization(PMF),and six potential pollution sources for PAHs and three for Cl-PAHs were quantified.PAHs primarily originate from the combustion of fossil fuels such as traffic,industrial emissions and coal tar,while Cl-PAHs are mainly derived from atmospheric deposition and industrial emissions.Meanwhile,the self‑organizing map classified PAHs and Cl-PAHs into 2 and 3 groups,respectively.The k-means algorithm yielded 4 clusters for runoff samples.Among machine learning models,Random Forest(RF)demonstrated optimal predictive performance and integrated with SHapley Additive exPlanations(RF-SHAP)revealed the effects of driving factors on the predicted concentration of PAHs and Cl-PAHs in urban runoff samples. 展开更多
关键词 Machine learning PAHS Cl-PAHs Positive matrix factorization RUNOFF Shapley additive explanations
原文传递
Prone position ventilation in severe acute pancreatitis patients with concurrent acute respiratory distress syndrome and abdominal compartment syndrome:a case report
7
作者 Jiaping Yu Yun Ji Haifei Lu 《World Journal of Emergency Medicine》 2026年第1期98-100,共3页
Severe acute pancreatitis(SAP)can induce acute respiratory distress syndrome(ARDS)and abdominal compartment syndrome(ACS).Although prone position ventilation(PPV)can improve outcomes in patients with ARDS,there is sig... Severe acute pancreatitis(SAP)can induce acute respiratory distress syndrome(ARDS)and abdominal compartment syndrome(ACS).Although prone position ventilation(PPV)can improve outcomes in patients with ARDS,there is significant controversy regarding its concurrent use with ACS owing to concerns of increased risk of intra-abdominal pressure(IAP).[1]We present a case of successful PPV application without adverse eff ects. 展开更多
关键词 severe acute pancreatitis sap can prone position ventilation ppv can acute respiratory distress syndrome abdominal compartment syndrome abdominal compartment syndrome acs prone position ventilation intra abdominal pressure acute respiratory distress syndrome ards
暂未订购
Research on Reactive Power Control Strategy for Small Extinction Angle Operation of Hybrid Commutation Converters
8
作者 Jiaxing Ning Xiaoguang Wei +3 位作者 Zhichang Yuan Longlong Chen Hui Du Zhanqing Yu 《Protection and Control of Modern Power Systems》 2026年第1期26-39,共14页
Hybrid commutation converters(HCCs)utilizing reverse-blocking integrated gate commutation thyristors(IGCTs)have gained significant attention due to their immunity to commutation failure.Leveraging the recovery enhance... Hybrid commutation converters(HCCs)utilizing reverse-blocking integrated gate commutation thyristors(IGCTs)have gained significant attention due to their immunity to commutation failure.Leveraging the recovery enhancement characteristics of IGCTs,HCCs demonstrate superior performance at reduced extinction angles,thereby minimizing reactive power consumption.This study presents a comprehensive investigation into reactive power control strategies for HCCs operating at small extinction angles.First,the topological configuration and commutation principle of HCC are elucidated.Subsequently,the mechanism of HCC reactive power control is analyzed,and a reactive power control strategy is proposed by combining the converter transformer taps with extinction angles.Moreover,the relationship between transformer taps and reactive power exchange under different rated extinction angles is calculated,and the theoretically rated extinction angle is proposed.Finally,to validate the proposed control strategy,a four-terminal ultra-high voltage direct current power grid incorporating HCC technology is modeled and sim-ulated using PSCAD/EMTDC.The simulation results demonstrate that the proposed strategy effectively supports AC systems by reducing reactive power absorption in HCCs,while simultaneously exhibiting enhanced reli-ability and economic efficiency. 展开更多
关键词 Commutation failure extinction angle HCC reactive power tap position
在线阅读 下载PDF
A conceptual analysis of reflective supervision for creating a positive intensive care practice environment
9
作者 Mpho Grace Chipu 《International Journal of Nursing Sciences》 2026年第1期88-95,共8页
Objectives This study aimed to explore and clarify the concept of reflective supervision as a professional self-care strategy to create a positive Intensive Care Unit(ICU)practice environment.Methods Walker and Avant... Objectives This study aimed to explore and clarify the concept of reflective supervision as a professional self-care strategy to create a positive Intensive Care Unit(ICU)practice environment.Methods Walker and Avant’s eight-step concept analysis approach was utilized to identify and define the attributes,antecedents,and consequences of reflective supervision in the ICU.An extensive literature search was conducted across various databases,including Google Scholar,CINAHL,PubMed.Articles published from 2005 to 2025 were identified.We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)2020 statement to indicate the included articles and extract related data based on relevance.Results Forty articles were included in the analysis.The identified attributes included the supervisor-supervisee relationship,effective communication,teamwork,collaborations,reflection,competencies,feedback,continuous support,and autonomous choice.The identified antecedents included participation,supportive supervision,flexibility,open-door policy,training,and motivation.Consequences impacting the success of reflective supervision were identified as promotion of resiliency,autonomy,work-life balance,self-awareness,increased self-esteem,professional development,critical thinking,increased job satisfaction,and enhanced commitment.Conclusions Reflective supervision is a complex professional self-care strategy that enhances ICU practice,by promoting nurses’well-being,self-awareness,therapeutic skills,and professional development. 展开更多
关键词 Concept analysis Intensive Care Unit NURSING Positive environment Reflective supervision
暂未订购
Curvilinear Supine Position for Pressure Injury Prevention in Pediatric Cardiac Surgery Patients:A Randomized Controlled Trial
10
作者 Qianxue Yang Xiuli Xiao +2 位作者 Minzhe Xing Shuo Qin Xian Li 《Journal of Clinical and Nursing Research》 2026年第1期345-353,共9页
Background:Pressure injury(PI)is a prevalent complication in pediatric cardiac surgery,with higher incidence than in general pediatric populations due to children’s thin skin,underdeveloped subcutaneous tissue,and pr... Background:Pressure injury(PI)is a prevalent complication in pediatric cardiac surgery,with higher incidence than in general pediatric populations due to children’s thin skin,underdeveloped subcutaneous tissue,and prolonged intraoperative pressure.Objective:To evaluate the effectiveness of the curvilinear supine position(CSP)in preventing PI among children undergoing congenital heart disease(CHD)surgery.Methods:Between October 2024 and February 2025,a single-center randomized controlled trial was conducted.Of the 80 children initially enrolled for congenital heart disease(CHD)surgery,77(aged 1 month to 14 years)completed the study and were included in the final analysis after 3 were excluded due to protocol violations.Participants were randomly assigned to the CSP group(n=38)or the conventional supine position group(n=39).Results:The incidence of PI was significantly lower in the CSP group(2.6%)compared to the control group(20.5%)(p=0.029).Postoperative LDH levels were also significantly reduced in the CSP group(422.67±86.52 U/L vs.592.92±215.71 U/L;p=0.031),while preoperative LDH and surgical variables(e.g.,cardiopulmonary bypass time)were comparable between groups.Although the CSP group had a shorter hospital stay(17.24 vs.22.51 days),the difference was not statistically significant(p=0.085).Caregiver satisfaction was significantly higher in the CSP group(100.0%vs.84.6%;p=0.025).Conclusion:CSP effectively reduces PI incidence,mitigates tissue injury,and enhances caregiver satisfaction in pediatric cardiac surgery,offering a safe and feasible strategy for perioperative PI prevention. 展开更多
关键词 Curvilinear supine position Pressure injury CHILDREN Perioperative nursing Cardiac surgery
暂未订购
The blow-up of solutions for porous medium equations with viscoelastic term under positive initial energy
11
作者 WU Xiu-lan ZHAO Ya-xin YANG Xiao-xin 《Applied Mathematics(A Journal of Chinese Universities)》 2026年第1期120-126,共7页
This paper deals with homogeneous Dirichlet boundary value problem to a class of porous medium equations with viscoelastic term ∂u/∂t-Δu^(m)+∫^(t)_(0)g(t-s)Δu^(m)(x,s)ds=u^(p),x∈Ω,t≥0,where p>m(m>0).We pro... This paper deals with homogeneous Dirichlet boundary value problem to a class of porous medium equations with viscoelastic term ∂u/∂t-Δu^(m)+∫^(t)_(0)g(t-s)Δu^(m)(x,s)ds=u^(p),x∈Ω,t≥0,where p>m(m>0).We prove that the weak solutions of the above problem blow up in finite time when the initial energy is positive and the function g satisfies suitable conditions.Our result generalizes that of S.A.Messaoudi in[1]. 展开更多
关键词 porous medium viscoelastic term blow up positive initial energy
在线阅读 下载PDF
Face-Saving Strategies in the Chinese Context:A Case Study of Post-match Interviews With Table Tennis Athletes
12
作者 WANG Wenjing ZHI Yuying 《Journal of Literature and Art Studies》 2026年第1期31-35,共5页
Post-match interview is a medium for athletes to showcase their impressions.This paper focus on the discourse of a post-match interview by Chinese athletes in the sport of table tennis at the 2024 Paris Olympics using... Post-match interview is a medium for athletes to showcase their impressions.This paper focus on the discourse of a post-match interview by Chinese athletes in the sport of table tennis at the 2024 Paris Olympics using the face-saving theory as the main framework introduced by Brown and Levinson(1987).In addition,theoretical extensions(Gu,1990;Mao,1994;Gao,1996)are also used to explain conceptions of face in the Chinese context.This study adopts a qualitative case study approach to investigating how athletes construct and maintain their face.It specifically analyzes the positive face,negative face,and redressive strategies.The findings indicate that Chinese athletes commonly adopt strategies such as emphasizing collective honor,humor,and indirect expressions to address face issues.These strategies are related to the collectivist values that are embedded in Chinese culture.This study extends the application of face theory to the under-explored domain of sports discourse and offers insights for future studies in sports communication and intercultural pragmatics. 展开更多
关键词 face-saving theory post-match interview positive face negative face
在线阅读 下载PDF
Mindfulness and internalizing/externalizing problems among adolescents:Ethnicity moderation and psychological capital mediation
13
作者 Jia Wu Wei Luo +4 位作者 Qianguo Xiao Qinhong Xie Xiaodong Li Taiyong Bi Hui Kou 《Journal of Psychology in Africa》 2026年第1期97-106,共10页
This study examines the mediating role of positive psychological capital and the moderating role of ethnicity in the relationship between mindfulness and internalizing/externalizing problems among adolescents.The stud... This study examines the mediating role of positive psychological capital and the moderating role of ethnicity in the relationship between mindfulness and internalizing/externalizing problems among adolescents.The study sample comprized Chinese adolescents(N=637 ethnic minority;females=40.97%,meam age=12.68,SD=0.49 years;N=636 Han;females=49.06%,mean age=12.71,SD=0.47 years).The participants completed the Child and Adolescent Mindfulness Measure,the Positive Psycap Questionnaire,and the Youth Self-Report.Results from the moderated mediation analysis showed mindfulness was negatively associated with both internalizing and externalizing problems.Ethnicity moderated the relationship between mindfulness and internalizing problems to be stronger for Han adolescents compared to ethnic minority adolescents.Psychological capital mediated the relationship between mindfulness and internalizing problems in both groups,with a negative direction.Findings support the Conservation of Resources theory and highlight mindfulness as a personal resource fostering adolescent well-being in multicultural contexts. 展开更多
关键词 Ethnic minority adolescent MINDFULNESS positive psychological capital internalizing problems externalizing problems
在线阅读 下载PDF
Assessing Flourishing in a Collectivist Context:Psychometric Evaluation of the Flourishing Scale in Chinese Middle School Students
14
作者 Baijun Chen Song Gui +2 位作者 Yujing Xie Lijun Ma Can Jiao 《International Journal of Mental Health Promotion》 2026年第3期72-81,共10页
Objectives:Flourishing,a central concept in positive psychology,encompasses multifaceted dimensions such as meaning,positive relationships,and engagement.Despite growing research interest,empirical studies focusing sp... Objectives:Flourishing,a central concept in positive psychology,encompasses multifaceted dimensions such as meaning,positive relationships,and engagement.Despite growing research interest,empirical studies focusing specifically on the flourishing of middle school students remain scarce.Given the critical need to promote flourishing among Chinese middle school students,the study aimed to adapt Diener’s Flourishing Scale for Chinese middle school students,examine its psychometric properties,and establish its measurement invariance across gender and time within this population.Methods:Participants were recruited from secondary schools in two Chinese provinces.The Chinese versions of the Flourishing Scale(CFS),along with the Index of Well-being(IWB)and the Satisfaction with Life Scale(SWLS),were employed.Data collection occurred in three phases,the first two for exploratory factor analysis(EFA)and confirmatory factor analysis(CFA),respectively,and the last one for testing longitudinal measurement invariance and gender measurement invariance.Results:The CFS demonstrated excellent discrimination and consistency with Diener’s original model.Significant positive correlations emerged between the CFS scores and well-being(r=0.75,p<0.01)as well as life satisfaction(r=0.74,p<0.01).Cronbach’sαwas 0.948,and the Pearson correlation coefficient(PCC)for test-retest reliability was 0.85(p<0.01).The CFS demonstrated strict measurement invariance across both gender and time.Conclusion:The CFS demonstrates robust psychometric properties—including structural validity,reliability,and measurement invariance—for its application among Chinese middle school students. 展开更多
关键词 Flourishing scale Chinese middle school students psychometric properties positive psychology
在线阅读 下载PDF
Lightweight Complex-Valued Neural Network for Indoor Positioning
15
作者 Le Wang Bing Xu +1 位作者 Peng Liu En Yuan 《Computers, Materials & Continua》 2026年第2期1770-1783,共14页
Deep learning has been recognized as an effective method for indoor positioning.However,most existing real-valued neural networks(RVNNs)treat the two constituent components of complex-valued channel state information(... Deep learning has been recognized as an effective method for indoor positioning.However,most existing real-valued neural networks(RVNNs)treat the two constituent components of complex-valued channel state information(CSI)as real-valued inputs,potentially discarding useful information embedded in the original CSI.In addition,existing positioning models generally face the contradiction between computational complexity and positioning accuracy.To address these issues,we combine graph neural network(GNN)with complex-valued neural network(CVNN)to construct a lightweight indoor positioning model named CGNet.CGNet employs complexvalued convolution operation to directly process the original CSI data,fully exploiting the correlation between real and imaginary parts of CSI while extracting local features.Subsequently,the feature values are treated as nodes,and conditional position encoding(CPE)module is applied to add positional information.To reduce the number of connections in the graph structure and lower themodel complexity,feature information is mapped to an efficient graph structure through a dynamic axial graph construction(DAGC)method,with global features extracted usingmaximum relative graph convolution(MRConv).Experimental results show that,on the CTW dataset,CGNet achieves a 10%improvement in positioning accuracy compared to existing methods,while the number of model parameters is only 0.8 M.CGNet achieves excellent positioning accuracy with very few parameters. 展开更多
关键词 Indoor positioning complex-valued neural network channel state information lightweight model
在线阅读 下载PDF
Oxidative potential of PM_(2.5) in Guangzhou,Southern China:Source apportionment and association with airborne bacteria
16
作者 Yuxin Huang Senchao Lai +7 位作者 Baoling Liang Jinpu Zhang Chenglei Pei Dachi Hong Xiaoluan Lin Zhaokang Ruan Leitao Sun Yingyi Zhang 《Journal of Environmental Sciences》 2026年第1期64-72,共9页
Oxidative potential(OP)can be used as an indicator of the health risks of particulate matter in the air.To study the variation and sources of OP,we conducted an observation of PM_(2.5) in a megacity in southern China ... Oxidative potential(OP)can be used as an indicator of the health risks of particulate matter in the air.To study the variation and sources of OP,we conducted an observation of PM_(2.5) in a megacity in southern China in winter and spring of 2021.The results show that the average concentration of PM_(2.5) decreased by 47%from winter to spring,while volume-normalized and mass-normalized OP(i.e.,OP_(v) and OP_(m))increased by 6%and 69%,respectively.It suggests that the decline of PM_(2.5) may not necessarily decrease the health risks and the intrinsic toxicity of PM_(2.5).Variations of OP_(v) and OP_(m) among different periods were related to the different source contributions and environmental conditions.The positive matrix factorization model was used to identify the major sources of OP_(v).OP_(v) was mainly contributed by biomass burning/industrial emissions(29%),soil/road dust(20%),secondary sulfate(14%),and coal combustion(13%)in winter.Different major sources were resolved to be secondary sulfate(36%),biological sources(21%),and marine vessels(20%)in spring,presenting the substantial contribution of biological sources.The analysis shows strong associations between OP_(v) and both live and dead bacteria,further confirming the important contribution of bioaerosols to the enhancement of OP.This study highlights the importance of understanding OP in ambient PM_(2.5) in terms of public health impact and provides a new insight into the biological contribution to OP. 展开更多
关键词 Oxidative potential PM_(2.5) Source apportionment Positive matrix factorization Airborne bacteria
原文传递
Unveiling the origins of Northern Thailand’s haze:comprehensive chemical characterization and source apportionment of PM_(2.5) using targeted molecular markers
17
作者 Supattarachai Saksakulkrai Somporn Chantara +2 位作者 Pavidarin Kraisitnitikul Deepchandra Srivastava Zongbo Shi 《Journal of Environmental Sciences》 2026年第1期635-648,共14页
Annual haze in Northern Thailand has become increasingly severe,impacting health and the environment.How-ever,the sources of the haze remain poorly quantified due to limited observational data on aerosol molecular tra... Annual haze in Northern Thailand has become increasingly severe,impacting health and the environment.How-ever,the sources of the haze remain poorly quantified due to limited observational data on aerosol molecular tracers.This study comprehensively investigates chemical composition of PM_(2.5),including both inorganic and organic compounds throughout haze and post-haze periods in 2019 at a rural site of Northern Thailand.Average PM_(2.5) concentrations during haze and post-haze period were 87±36 and 21±11μg/m^(3),respectively.Organic matter was the dominant contributor in PM_(2.5) mass,followed by water soluble inorganic ions and mineral dust.Molecular markers,including levoglucosan,dehydroabietic acid,and 4-nitrocatechol,and ions(Cl^(-),and K^(+)),were used to characterize low haze(PM_(2.5)<100μg/m^(3))and episodic haze(PM_(2.5)>100μg/m^(3)).Low haze is associated with local aerosols from agricultural waste burning,while episodic haze is linked to aged aerosols from mixed agricultural waste,softwood,and hardwood burning.Source apportionment incorporating these molecular markers in receptor modelling(Positive matrix factorization),identified three distinct biomass burning sources:mixed,local,and aged biomass burnings,contributing 31,19 and 13%of PM_(2.5) during haze period.During post-haze period,contributions shifted,with local biomass burning(32%)comparable to secondary sulfate(34%)and mixed dust and traffic sources(26%).These findings demonstrate that both regional and local sources con-tribute to severe haze,highlighting the need for integrated policies for cross-border cooperation as well as stricter regulations to reduce biomass burning in Northern Thailand and Southeast Asia. 展开更多
关键词 Chiang Mai Smoke haze Biomass burning PM_(2.5) Source apportionment Positive matric factorization
原文传递
Workspace-based hybrid force position posture alignment for high quality aircraft assembly of large-scale components
18
作者 Yajun LI Wei LIU +4 位作者 Hu LU Runze LIU Changyong GAO Qihang CHEN Yang ZHANG 《Chinese Journal of Aeronautics》 2026年第1期553-569,共17页
The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input mult... The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input multi-output,nonlinearity,and strong coupling presents significant challenges.The substantial internal force generated during the adjustment process can potentially damage the LAC and degrade the assembly quality.Hence,a workspace-based hybrid force position control scheme was developed to achieve high quality assembly with high-precision and lower internal force.Firstly,an offline workspace analysis with inherent geometric characteristics to form time-varying posture error constraint.Then,the posture error is integrated into the online position axis control to ensure tracking the ideal posture,while the force control axis compensates for posture deviation by minimizing internal force,thereby achieving high precision and low internal force.Finally,the effectiveness was demonstrated through experiments.The root mean square errors of orientation and position are 104 rad and 0.1 mm,respectively.A reduction in internal force can range from 10.96%to 57.4%compared to the traditional method.Key points'max position error is decreased from 0.32 mm to 0.18 mm,satisfying the 0.5 mm tolerance.Therefore,the proposed method will help promote the development of high-performance manufacturing. 展开更多
关键词 Aircraft manufacture Posture alignment Hybrid constraints Workspace analysis Hybrid force position control Internal force
原文传递
Postoperative effective lens position and refraction changes with three different types of intraocular lens
19
作者 Xi-Xia Ding Lin-Feng Xiang +5 位作者 Wen-Tao Tong Dan-Dan Wang Hong-FangZhang Ping-Jun Chang Fu-Man Yang Yun-E Zhao 《International Journal of Ophthalmology(English edition)》 2026年第2期260-265,共6页
AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 group... AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs. 展开更多
关键词 effective lens position REFRACTION intraocular lens swept-source optical coherence tomography
原文传递
Structural Reliability Analysis Based on Differential Evolution Algorithm and Hypersphere Integration
20
作者 CHEN Zhenzhong HAN Zhuo +4 位作者 WANG Peiyu PAN Qianghua LI Xiaoke GAN Xuehui CHEN Ge 《Journal of Donghua University(English Edition)》 2026年第1期118-130,共13页
In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order relia... In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order reliability methods exhibit limited accuracy in highly nonlinear scenarios.To overcome these challenges,a novel reliability analysis strategy based on a multimodal differential evolution algorithm and a hypersphere integration method is proposed.Initially,the penalty function method is employed to reformulate the MPP search problem as a conditionally constrained optimization task.Subsequently,a differential evolution algorithm incorporating a population delineation strategy is utilized to identify all MPPs.Finally,a paraboloid equation is constructed based on the curvature of the limit-state function at the MPPs,and the failure probability of the structure is calculated by using the hypersphere integration method.The localization effectiveness of the MPPs is compared through multiple numerical cases and two engineering examples,with accuracy comparisons of failure probabilities against the first-order reliability method(FORM)and the secondorder reliability method(SORM).The results indicate that the method effectively identifies existing MPPs and achieves higher solution precision. 展开更多
关键词 reliability analysis design point positioning differential evolution algorithm hypersphere integration
在线阅读 下载PDF
上一页 1 2 239 下一页 到第
使用帮助 返回顶部