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Mediating Effect of Mindfulness,Self-Esteem and Psychological Resilience in the Relation between Childhood Maltreatment and Life Satisfaction
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作者 He Zhong Yaping Zhou +1 位作者 Chenwei Liu Yintao Cao 《International Journal of Mental Health Promotion》 2024年第6期481-489,共9页
Childhood maltreatment,as a typical early adverse environment,is known to have a negative impact on one’s life satisfaction.Mindfulness,on the other hand,may serve as a protective factor.This study explored the media... Childhood maltreatment,as a typical early adverse environment,is known to have a negative impact on one’s life satisfaction.Mindfulness,on the other hand,may serve as a protective factor.This study explored the mediating role of mindfulness and its related variables–positive thoughts,psychological resilience and self-esteem.In order to testify the mechanism,we administered Childhood Trauma Questionnaire(CTQ),Satisfaction with Life Scale(SWLS),Mindful Attention Awareness Scale(MAAS),Connor–Davidson Resilience Scale(CD-RISC)and Rosenberg Self-Esteem Scale(RSES)to a non-clinical sample of Chinese university students(N=1021).The results indicated that positive thoughts did not mediate the relationship between childhood maltreatment and life satisfaction,but self-esteem(β=−0.194,95%CI=[−0.090,−0.040])and psychological resilience(β=−0.063,95%CI=[−0.059,−0.020])mediated the relationship,as well as the“mindfulness-selfesteem”(β=−0.061,95%CI=[−0.287,−0.126])and“mindfulness-psychological resilience”(β=−0.035,95%CI=[−0.115,−0.034]).The results of this study were helpful to understand the relationship between childhood maltreatment and life satisfaction and provided a theoretical basis for the development of mindfulness intervention programs from the perspective of positive psychology. 展开更多
关键词 MINDFULNESS childhood maltreatment life satisfaction self-esteem RESILIENCE
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The Influence of Vulnerable Narcissism on Social Anxiety among Adolescents:The Mediating Role of Self-Concept Clarity and Self-Esteem
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作者 Yuetan Wang Xianle Yan +3 位作者 Lili Liu Xiran Lu Lan Luo Xiaobin Ding 《International Journal of Mental Health Promotion》 2024年第6期429-438,共10页
Social anxiety (SA) is a prevalent mental health issue among adolescents, and vulnerable narcissism (VN) can exacerbate thiscondition. This study aims to investigate the impact of vulnerable narcissism on social anxie... Social anxiety (SA) is a prevalent mental health issue among adolescents, and vulnerable narcissism (VN) can exacerbate thiscondition. This study aims to investigate the impact of vulnerable narcissism on social anxiety in adolescents, specificallyfocusing on the mediating effects of self-concept clarity (SCC) and self-esteem (SE) in the relationship between vulnerablenarcissism and social anxiety. Through cluster sampling, a questionnaire survey was conducted among 982 students from threesecondary schools in two provinces. The data was analyzed using structural equation modeling (SEM). The results revealedthat there was a significant negative correlation between vulnerable narcissism and both self-concept clarity and self-esteem,while there was a significant positive correlation between vulnerable narcissism and social anxiety. Additionally, self-conceptclarity showed a significant positive correlation with self-esteem but had a negative correlation with social anxiety. Both selfconceptclarity and self-esteem played an intermediary role in the chain linking vulnerable narcissism to social anxiety. Thisstudy confirms the mediating role of both self-concept clarity and self-esteem in explaining how vulnerable narcissisminfluences social anxiety, providing valuable insights into its underlying mechanism. 展开更多
关键词 Social anxiety vulnerable narcissism self-concept clarity self-esteem ADOLESCENT
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Disparities in the impact of economic well-being on self-esteem in adulthood:Race and ethnicity
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作者 Jaewon Lee 《World Journal of Psychiatry》 SCIE 2024年第2期296-307,共12页
BACKGROUND Most studies have defined economic well-being as socioeconomic status,with little attention given to whether other indicators influence self-esteem.Little is known about racial/ethnic disparities in the rel... BACKGROUND Most studies have defined economic well-being as socioeconomic status,with little attention given to whether other indicators influence self-esteem.Little is known about racial/ethnic disparities in the relationship between economic wellbeing and self-esteem during adulthood.AIM To explore the impact of economic well-being on self-esteem in adulthood and differences in the association across race/ethnicity.METHODS The current study used data from the National Longitudinal Survey of Youth 1979.The final sample consisted of 2267 African Americans,1425 Hispanics,and 3678 non-Hispanic Whites.Ordinary linear regression analyses and logistic regression analyses were conducted.RESULTS African Americans and Hispanics were more likely to be in poverty in comparison with non-Hispanic Whites.More African Americans were unemployed than Whites.Those who received fringe benefits,were more satisfied with jobs,and were employed were more likely to have higher levels of self-esteem.Poverty was negatively associated with self-esteem.Interaction effects were found between African Americans and job satisfaction predicting self-esteem.CONCLUSION The role of employers is important in cultivating employees’self-esteem.Satisfactory outcomes or feelings of happiness from the workplace may be more important to non-Hispanic Whites compared to African Americans and Hispanics. 展开更多
关键词 Economic well-being self-esteem Racial/Ethnic disparities ADULTHOOD
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The Relationship between Self-Esteem and Social Phobia among College Students:The Mediating Effect of Fear of Negative Evaluation and the Moderating Effect of Perfectionism
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作者 Shuai Lv Zhaojun Chen +3 位作者 Jian Mao Hui Wang Peibo Wu Yujuan Hai 《International Journal of Mental Health Promotion》 2024年第6期491-498,共8页
Objectives:To explore the relationship between college students’self-esteem(SE)and their social phobia(SP),as well as the mediating role of fear of negative evaluation(FNE)and the moderating effect of perfectionism.M... Objectives:To explore the relationship between college students’self-esteem(SE)and their social phobia(SP),as well as the mediating role of fear of negative evaluation(FNE)and the moderating effect of perfectionism.Methods:A convenience sampling survey was carried out for 1020 college students from Shandong Province of China,utilizing measures of college students’self-esteem,fear of negative evaluation,perfectionism,and social phobia.Data analysis was performed using the SPSS PROCESS macro.Results:(1)college students’self-esteem significantly and negatively predicts their social phobia(β=−0.31,t=−10.10,p<0.001);(2)fear of negative evaluation partially mediates the relation between self-esteem and social phobia among college students,with the mediating effect accounting for 48.97%of the total effect(TE);(3)the mediating role of fear of negative evaluation is moderated by perfectionism(β=0.18,t=7.75,p<0.001),where higher levels of perfectionism strengthen the mediating effect of fear of negative evaluation.Conclusions:Perfectionism moderates the mediating effect that fear of negative evaluation plays,establishing a moderated mediating model. 展开更多
关键词 self-esteem fear of negative evaluation PERFECTIONISM social phobia
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Self-Compassion Moderates the Effect of Contingent Self-Esteem on Well-Being:Evidence from Cross-Sectional Survey and Experiment
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作者 Ruirui Zhang Xuguang Zhang +1 位作者 Minxin Yang Haoran Zhang 《International Journal of Mental Health Promotion》 2024年第2期117-126,共10页
Contingent self-esteem captures the fragile nature of self-esteem and is often regarded as suboptimal to psychological functioning.Self-compassion is another important self-related concept assumed to promote mental he... Contingent self-esteem captures the fragile nature of self-esteem and is often regarded as suboptimal to psychological functioning.Self-compassion is another important self-related concept assumed to promote mental health and well-being.However,research on the relation of self-compassion to contingent self-esteem is lacking.Two studies were conducted to explore the role of selfcompassion,either as a personal characteristic or an induced mindset,in influencing the effects of contingent self-esteem on well-being.Study 1 recruited 256 Chinese college students(30.4%male,mean age=21.72 years)who filled out measures of contingent self-esteem,self-compassion,and well-being.The results found that self-compassion moderated the effect of contingent self-esteem on well-being.In Study 2,a sample of 90 Chinese college students(34%male,mean age=18.39 years)were randomly assigned to either a control or self-compassion group.They completed baseline trait measures of contingent self-esteem,self-compassion,and self-esteem.Then,they were led to have a 12-min break(control group)or listen to a 12-min self-compassion audio(self-compassion group),followed by a social stress task and outcome measures.The results demonstrated the effectiveness of the brief self-compassion training and its moderating role in influencing the effects of contingent self-esteem on negative affects after the social stress task.This research provides implications that to equip with a self-compassionate mindset could lower the risk of the impairment of well-being associated with elements of contingent selfesteem,which involves a fragile sense of self-worth.It may also provide insights into the development of an“optimal selfesteem”and the improvement of well-being. 展开更多
关键词 SELF-COMPASSION contingent self-esteem WELL-BEING social evaluative threat
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Euler’s First-Order Explicit Method–Peridynamic Differential Operator for Solving Population Balance Equations of the Crystallization Process
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作者 Chunlei Ruan Cengceng Dong +2 位作者 Kunfeng Liang Zhijun Liu Xinru Bao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期3033-3049,共17页
Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridyna... Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed. 展开更多
关键词 Population balance equation CRYSTALLIZATION peridynamic differential operator Euler’s first-order explicit method
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An efficient method for train-track-substructure dynamic interaction analysis by implicit-explicit integration and multi-time-step solution 被引量:1
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作者 Lei Xu Wanming Zhai +1 位作者 Shengyang Zhu Weizheng Liu 《Railway Engineering Science》 2023年第1期20-36,共17页
In this work,a method is put forward to obtain the dynamic solution efficiently and accurately for a large-scale train-track-substructure(TTS)system.It is called implicit-explicit integration and multi-time-step solut... In this work,a method is put forward to obtain the dynamic solution efficiently and accurately for a large-scale train-track-substructure(TTS)system.It is called implicit-explicit integration and multi-time-step solution method(abbreviated as mI-nE-MTS method).The TTS system is divided into train-track subsystem and substruc-ture subsystem.Considering that the root cause of low effi-ciency of obtaining TTS solution lies in solving the alge-braic equation of the substructures,the high-efficient Zhai method,an explicit integration scheme,can be introduced to avoid matrix inversion process.The train-track system is solved by implicitly Park method.Moreover,it is known that the requirement of time step size differs for different sub-systems,integration methods and structural frequency response characteristics.A multi-time-step solution is pro-posed,in which time step size for the train-track subsystem and the substructure subsystem can be arbitrarily chosen once satisfying stability and precision demand,namely the time spent for m implicit integral steps is equal to n explicit integral steps,i.e.,mI=nE as mentioned above.The numeri-cal examples show the accuracy,efficiency,and engineering practicality of the proposed method. 展开更多
关键词 Train-track dynamic interaction Substructure system Implicit integration explicit integration Multi-time-step solution Railway engineering
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Personality and Nomophobia: A Moderated Mediation Model of Self-Esteem and Non-Self-Determined Solitude
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作者 Yuxin Li Fengping Yan +2 位作者 Yixin Zhang Man Li Tour Liu 《International Journal of Mental Health Promotion》 2023年第6期767-781,共15页
Background:With the development of information technology,mobile phone has brought much convenience to people’s lives but also caused many negative consequences due to excessive use,such as mobile phone addiction and... Background:With the development of information technology,mobile phone has brought much convenience to people’s lives but also caused many negative consequences due to excessive use,such as mobile phone addiction and nomophobia.Previous studies have explored the relationship between the Big Five Personality and proble-matic mobile phone use(PMPU).However,they focus on mobile phone addiction.Although there is a correlation between nomophobia and mobile phone addiction,the psychological structure is different.Therefore,it is neces-sary to explore the relationship between personality and nomophobia and the underlying mechanism.This study aims to examine the relationship between Big Five Personality and nomophobia,then construct a moderated mediation model to explore the mediation effect of solitude between Big Five Personality and nomophobia,as well as the moderation effect of self-esteem.Method:Data from 678 college students(351 females,51.77%)were collected.Participants completed the Big Five Personality Inventory,Solitude Behavior Scale,Nomophobia Scale and Self-esteem Scale.Analyses were conducted via mediation and moderated mediation.Results:Structural equation models revealed that solitude mediated the relationship between neuroticism and nomophobia.The results showed that neuroticism positively predicted solitude,which in turn positively predicted nomophobia.Four types of solitude partially mediated the relationship between neuroticism and nomophobia.We also found that self-esteem moderated the association between neuroticism and non-self-determined solitude.It is note-worthy that high self-esteem cannot protect people from negative factors.However,because of its characteristics,it is easy to receive more social information,and people high in neuroticism are sensitive to negative social infor-mation.It may cause maladaptive behavior.Conclusion:Findings demonstrated a process through which neu-roticism relates to nomophobia and a context under which these relationships may have occurred. 展开更多
关键词 PERSONALITY nomophobia self-esteem SOLITUDE structural equation model
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Explicit K-symplectic methods for nonseparable non-canonical Hamiltonian systems
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作者 朱贝贝 纪伦 +1 位作者 祝爱卿 唐贻发 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期60-79,共20页
We propose efficient numerical methods for nonseparable non-canonical Hamiltonian systems which are explicit,K-symplectic in the extended phase space with long time energy conservation properties. They are based on ex... We propose efficient numerical methods for nonseparable non-canonical Hamiltonian systems which are explicit,K-symplectic in the extended phase space with long time energy conservation properties. They are based on extending the original phase space to several copies of the phase space and imposing a mechanical restraint on the copies of the phase space. Explicit K-symplectic methods are constructed for two non-canonical Hamiltonian systems. Numerical tests show that the proposed methods exhibit good numerical performance in preserving the phase orbit and the energy of the system over long time, whereas higher order Runge–Kutta methods do not preserve these properties. Numerical tests also show that the K-symplectic methods exhibit better efficiency than that of the same order implicit symplectic, explicit and implicit symplectic methods for the original nonseparable non-canonical systems. On the other hand, the fourth order K-symplectic method is more efficient than the fourth order Yoshida’s method, the optimized partitioned Runge–Kutta and Runge–Kutta–Nystr ¨om explicit K-symplectic methods for the extended phase space Hamiltonians, but less efficient than the the optimized partitioned Runge–Kutta and Runge–Kutta–Nystr ¨om extended phase space symplectic-like methods with the midpoint permutation. 展开更多
关键词 non-canonical Hamiltonian systems NONSEPARABLE explicit K-symplectic methods splitting method
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Impact of community-based rehabilitation on quality of life and self-esteem of persons with physical disabilities and their family members
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作者 Joseph Umunnah Babatunde Adegoke +2 位作者 Chigozie Uchenwoke Chinonso Igwesi-Chidobe Grace Alom 《Global Health Journal》 2023年第2期87-93,共7页
Objective:Community-based rehabilitation(CBR)is a strategy by which persons living with disability(PWDs)access comprehensive rehabilitation services with limited evidence regarding its impact on the quality of life(QO... Objective:Community-based rehabilitation(CBR)is a strategy by which persons living with disability(PWDs)access comprehensive rehabilitation services with limited evidence regarding its impact on the quality of life(QOL)and self-esteem(SE)of PWDs and their family members.This study compared the QOL and SE of Nigerian PWDs in communities with and without a CBR programme(CBR and non-CBR respectively),and the family quality of life(FQOL)of their family members.Methods:Cross-sectional study involving 2604 PWDs(1302 in CBR and 1302 in non-CBR);5208 family members of PWDs(2604 in CBR and 2604 non-CBR),recruited from four randomly selected geo-political zones in Nigeria,purposive/consecutive selection of eight CBR programmes,PWDs and their family members(CBR and non-CBR).Outcomes assessed using Rosenberg Self-Esteem Scale(RSES),World Health Organization Quality of Life Instrument-short form(WHOQOL-BREF)and Beach Centre Family Quality of Life Instrument(BCFQOL).Mann-Whitney U test and Spearman's rank order correlation were used to analyse data at P<0.05.Results:PWDs in CBR scored higher in all domains of WHOQOL-BREF(P<0.0001 in all cases)and RSES than non-CBR group(P<0.0001).The CBR families scored significantly higher than non-CBR families in all domains(P<0.05)except Emotional Well-Being of the BCFQOL.The CBR group scores on Psychological and Social Health domains of the WHOQOL-BREF showed significant positive correlation with CBR families'Family Interaction(P=0.06)and Parenting(P=0.07)domains and total FQOL(P=0.07).Conclusion:Community-based rehabilitation positively impacted on SE and QOL of PWDs and their family members. 展开更多
关键词 Community-based rehabilitation Persons living with disability Quality of life self-esteem
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The Influence of Self-esteem on College Students’Learning Burnout:A Mediation Model
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作者 MENG Xiangyin ZHANG Lei OU Guiyu 《Psychology Research》 2023年第7期312-318,共7页
We measured 324 college students’self-esteem,motivation for achievement,and learning burnout,and also we examined the inner mechanism of self-esteem’s influence on students’learning burnout.The results show:(1)Ther... We measured 324 college students’self-esteem,motivation for achievement,and learning burnout,and also we examined the inner mechanism of self-esteem’s influence on students’learning burnout.The results show:(1)There is a negative effect of self-esteem on college students’learning burnout;(2)Motivation of pursuing succeed plays partial mediating effect between self-esteem and learning burnout,but mediating effect of avoiding failure motivation between them is not significant.The study reveals that:the degree of learning burnout can be reduced by improving college students’level of self-esteem. 展开更多
关键词 college students self-esteem learning burnout motivation for achievement
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The Effectiveness of Explicit Vocabulary Instruction on Productive Vocabulary Learning in Writing Among Intermediate School Learners in Saudi Arabia
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作者 Salih Alzahrani Meshal Alhomyani 《Sino-US English Teaching》 2023年第8期289-310,共22页
This study aimed to identify the effectiveness of explicit vocabulary instruction on productive vocabulary learning in writing among intermediate school learners in Saudi Arabia,verify the existence of any statistical... This study aimed to identify the effectiveness of explicit vocabulary instruction on productive vocabulary learning in writing among intermediate school learners in Saudi Arabia,verify the existence of any statistically significant differences at the significance level of 0.01 between the mean scores of the post-test of the control group and the experimental group in the vocabulary test,and verify the existence of any statistically significant differences at the significance level of 0.01 between the mean scores of the pre-and post-test of the experimental group in the vocabulary test in favor of the post-test.The study community consisted of all intermediate school students in the Kingdom of Saudi Arabia,while the study sample included 30 students.The experimental method was adopted to identify the effectiveness of explicit vocabulary instruction on productive vocabulary learning in writing and the achievement test was used as the study tool.The study reached many results including there were no statistically significant differences at the significance level of 0.01 between the mean scores of the post-test of the control group and the experimental group in the vocabulary test and there were no statistically significant differences at the significance level of 0.01 between the mean scores of the pre-and post-test of the experimental group in the vocabulary test in favor of the post-test.According to these results,some recommendations and proposals were made including training English teachers at the intermediate school level in the Kingdom of Saudi Arabia,on explicit vocabulary instruction and conducting future researches on the trends of English teachers at the intermediate school level,in the Kingdom of Saudi Arabia,regarding the adoption of explicit vocabulary instruction while teaching the English language. 展开更多
关键词 VOCABULARY explicit vocabulary productive vocabulary INSTRUCTION LEARNERS intermediate school
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新时代青年大学生爱国主义的变迁与启示
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作者 陶志欢 《北京青年研究》 2024年第2期54-61,共8页
新时代青年大学生爱国主义的积极变化主要表现在:展现空间上,新时代青年大学生更加注重在合作开放的全球化中谋取正当的民族权益,网络爱国行动更加积极主动;表现形式上,新时代青年大学生的理性爱国成分占比逐步增加,爱国行为更为匹配爱... 新时代青年大学生爱国主义的积极变化主要表现在:展现空间上,新时代青年大学生更加注重在合作开放的全球化中谋取正当的民族权益,网络爱国行动更加积极主动;表现形式上,新时代青年大学生的理性爱国成分占比逐步增加,爱国行为更为匹配爱国认知;心理状态上,新时代青年大学生正在从外显自尊向真实自豪转变,反向表达多是为了抒发正向情感。这些变迁启示我们:新时代青年大学生的爱国主义教育未来应以复杂的全球化和加速的网络化为主要场域,应以言行理性化和实践指向性为主要方向,应以国家现代化和民众获得感为主要基础。 展开更多
关键词 外显自尊 真实自豪 正向情感 反向表达
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基于偏航机动的常推力定点着陆制导方法
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作者 李骥 张洪华 +1 位作者 张晓文 关轶峰 《深空探测学报(中英文)》 CSCD 北大核心 2024年第1期47-55,共9页
实现定点着陆终端位置速度六分量控制通常需要发动机推力可调。提出了一种通过偏航机动实现固定推力下的定点着陆制导方法。该方法通过偏转航向角,调节发动机输出在下降轨迹平面内的分量,从而实现航程控制;为了消除推力方向偏转产生的... 实现定点着陆终端位置速度六分量控制通常需要发动机推力可调。提出了一种通过偏航机动实现固定推力下的定点着陆制导方法。该方法通过偏转航向角,调节发动机输出在下降轨迹平面内的分量,从而实现航程控制;为了消除推力方向偏转产生的横向位置、速度偏差,设计了偏转角符号调整策略,使得着陆器在水平面内呈“之”字形运动,以一定推进剂为代价,最终保证了下降着陆终端位置、速度的全部可控。仿真表明,所提方法简单有效,易于工程实施。 展开更多
关键词 动力下降 定点着陆 常推力 显式制导
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新一代Wi-Fi的新型感知信息压缩方法
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作者 赵彬 徐骏 +1 位作者 张云 朱翔 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2024年第5期12-18,共7页
通信设备由于和雷达设备的工作存在重叠,也可以实现目标检测。但是传统的通信协议采用显式反馈传输信息,导致采用通信设备检测无法保留感知信息,因此可以对显式反馈的分解流程进行改进,从而在通信的间隙实现对环境目标的感知。在MIMO系... 通信设备由于和雷达设备的工作存在重叠,也可以实现目标检测。但是传统的通信协议采用显式反馈传输信息,导致采用通信设备检测无法保留感知信息,因此可以对显式反馈的分解流程进行改进,从而在通信的间隙实现对环境目标的感知。在MIMO系统中,波束成型是发射端利用MIMO信道状态信息生成导向矩阵,从而提升接收端接收性能的一种技术。目前显式反馈波束成型是通信中波束成型的主流方式,接收端会对接收到的信道矩阵进行奇异值分解后转换成一系列角度值传回发射端。虽然采用传统的矩阵分解流程获得反馈矩阵可以有效降低反馈的冗余信息量,但是通常会丢失掉通信设备在感知过程中获得的大部分重要信息,从而导致利用Wi-Fi信号进行目标探测的功能受到限制。研究发现对于接收到的信道矩阵利用传统的分解方式获得的反馈矩阵特征向量无法保留目标的距离,速度信息。本文提出了一种新型的分解方式,基于信道矩阵的协方差矩阵,先求解左奇异矩阵,再利用左右两个酉矩阵正交向量的对应关系,进一步求解从而获得改进的右奇异矩阵,所提改进方法保留了目标的距离、速度以及角度信息,极大地提升了有效反馈信息量。最后通过仿真实验验证了所提方法的有效性。 展开更多
关键词 MIMO 波束成型 显式反馈 奇异值分解
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扣件刚度非线性对波磨区轮轨瞬态滚动接触行为的影响
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作者 徐井芒 梁新缘 +2 位作者 王凯 赵思琪 王平 《西南交通大学学报》 EI CSCD 北大核心 2024年第2期247-255,共9页
WJ-8型扣件橡胶垫板刚度在长期服役过程中表现出非线性特征,静刚度随荷载增加而降低,为提高三维瞬态滚动接触有限元模型计算精确性,本文以LMA踏面车轮及CHN60型钢轨为基础,基于显式积分算法,将以往研究中线弹性扣件转化为非线性扣件,建... WJ-8型扣件橡胶垫板刚度在长期服役过程中表现出非线性特征,静刚度随荷载增加而降低,为提高三维瞬态滚动接触有限元模型计算精确性,本文以LMA踏面车轮及CHN60型钢轨为基础,基于显式积分算法,将以往研究中线弹性扣件转化为非线性扣件,建立考虑扣件刚度非线性特征的三维轮轨瞬态滚动接触有限元模型,研究刚度非线性对车轮与钢轨波磨间高频动态响应及瞬态接触行为的影响,并重点分析了波磨工况下时频域内轮轨接触力、轴箱加速度的变化信息.结果表明:扣件非线性对轮轨接触力变化影响明显,主要表现为车轮行驶至扣件前端时强振动导致橡胶垫板表现为柔软特性使轮轨接触力减小,车轮行驶至扣件上方时在轴重作用下振动减弱表现为刚硬特性使轮轨接触力增大,轮轨力变化差异最大达到13.1%. 展开更多
关键词 刚度非线性 瞬态滚动接触 波磨 显式有限元法
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物理师范生核心素养培养的研究与实践
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作者 赖国忠 梁雄 +1 位作者 沈秀球 吕晶 《龙岩学院学报》 2024年第2期64-67,共4页
核心素养培养是基础物理教育的热点问题。在物理师范专业开展核心素养培养有助于落实“以学生发展为中心”的教育教学理念,促进师范生对物理学科特点的理解和教学素养的感悟。为此,必须显性地开展核心素养培养,把核心素养既作为教学理... 核心素养培养是基础物理教育的热点问题。在物理师范专业开展核心素养培养有助于落实“以学生发展为中心”的教育教学理念,促进师范生对物理学科特点的理解和教学素养的感悟。为此,必须显性地开展核心素养培养,把核心素养既作为教学理念也作为教学内容;引导学生学会反思与讨论;把核心素养纳入考核内容。同时,要为核心素养培养提供保障。 展开更多
关键词 物理 师范生 核心素养 显性培养
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单步无条件稳定显式结构动力学算法
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作者 李常青 李正藩 蒋丽忠 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第3期1136-1145,共10页
在结构动力学分析中,数值积分方法通常被用来高效和准确地求解复杂结构系统在动态负载下的响应。基于量纲分析的原理,提出一种求解结构动力学问题的单步无条件稳定显式算法。首先对所构造的关于位移和速度的函数关系式进行无量纲化处理... 在结构动力学分析中,数值积分方法通常被用来高效和准确地求解复杂结构系统在动态负载下的响应。基于量纲分析的原理,提出一种求解结构动力学问题的单步无条件稳定显式算法。首先对所构造的关于位移和速度的函数关系式进行无量纲化处理,然后通过算法精度要求、无条件稳定条件和数值阻尼可控条件确定了其最终递推格式,并根据算法最终递推格式分析得出算法耗散与弥散特性、超调和自启动特性和多自由度系统计算步骤,最后通过数值算例验证了算法的收敛精度、可控数值阻尼和计算效率优势。研究结果表明:对于线性和非线性系统,该算法都兼具显式算法的非迭代特性和隐式算法的无条件稳定特性;该算法能实现真正意义上的自启动并且在速度和位移上均无超调;该算法的数值阻尼由单自由参数控制,数值耗散和弥散对系统低模态响应的影响可以忽略不计,与具有代表性的非迭代显式算法KR-α法相比,该算法在引入数值阻尼滤除虚假高频模态的同时更真实地保留了低阶振型的贡献,从而表现出更好的计算精度;该算法在求解非线性结构动力学问题时相较于常用隐式算法有着显著的计算效率优势,并略优于两求解器非迭代显式算法KR-α法。研究结果很有希望成为求解非线性结构动力学问题的最新且更加有效的显式算法。 展开更多
关键词 显式算法 非迭代算法 无条件稳定 可控数值阻尼 结构动力计算
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长持时爆炸冲击波作用下钢梁动力响应分析
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作者 杜晓庆 费智达 +1 位作者 柳扬清 邱涛 《科学技术与工程》 北大核心 2024年第4期1654-1661,共8页
大规模爆炸时引起的长持时平面爆炸波会造成结构的整体破坏,与接触爆炸或近场爆炸的破坏模式有显著差异,但相关研究不多。为研究长持时冲击波作用下钢梁的动力响应,首先基于耦合欧拉-拉格朗日方法建立了大型数值激波管模型,然后采用该... 大规模爆炸时引起的长持时平面爆炸波会造成结构的整体破坏,与接触爆炸或近场爆炸的破坏模式有显著差异,但相关研究不多。为研究长持时冲击波作用下钢梁的动力响应,首先基于耦合欧拉-拉格朗日方法建立了大型数值激波管模型,然后采用该数值激波管得到作用在钢梁上的反射超压时程,最后通过显式动力学方法研究了冲击波入射方向、持时、超压等参数对钢梁破坏模式的影响规律。结果表明:本文提出的数值激波管模型能较好地模拟长持时爆炸波的绕射现象,可得到可靠的反射超压和冲量时程;随着冲击波入射角度的增加,简支钢梁跨中位移增大;冲击波超压峰值相同时,随着持时的增加,简支梁跨中的最大位移有增大的趋势,最大位移的增长速率则会变缓;简支钢梁在长持时爆炸冲击波作用下容易发生受弯破坏,梁跨中翼缘板会出现局部屈曲现象。 展开更多
关键词 数值激波管 长持时冲击波 显式动力学 动力响应
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一种结构不确定分析的改进多维平行六面体模型
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作者 乔心州 张锦瑞 +1 位作者 方秀荣 刘鹏 《兵工学报》 EI CAS CSCD 北大核心 2024年第6期1877-1888,共12页
多维平行六面体模型是一种能够同时考虑相关变量和独立变量的非概率凸集模型,更适用于工程结构中常见的多源不确定性问题。为更加有效合理地度量结构不确定性,提出一种改进多维平行六面体模型。通过定义区间变量的相关角和边缘区间,给... 多维平行六面体模型是一种能够同时考虑相关变量和独立变量的非概率凸集模型,更适用于工程结构中常见的多源不确定性问题。为更加有效合理地度量结构不确定性,提出一种改进多维平行六面体模型。通过定义区间变量的相关角和边缘区间,给出模型不确定域的显式表达式,进而给出依据实验样本点构建多维平行六面体模型的方法。3个算例分析结果表明,改进多维平行六面体模型能够较好地反映区间变量之间的相关性,是一种比传统多维平行六面体模型更为紧凑合理的模型。 展开更多
关键词 多维平行六面体模型 非概率凸集模型 变量相关性 不确定域显式表达式
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