In this paper,the work hardening and softening behavior of AZ31 magnesium alloy sheets by hard plate accumulative roll bonding(HP-ARB)process in a specific temperature range was studied for the first time,and the cycl...In this paper,the work hardening and softening behavior of AZ31 magnesium alloy sheets by hard plate accumulative roll bonding(HP-ARB)process in a specific temperature range was studied for the first time,and the cyclic stress relaxation test,EBSD,TEM and other characterization methods were used.When the rolling temperature is 350℃,the grain size of magnesium sheets is refined to 4.32(±0.36)μm on average,and it shows an excellent combination of strength and plasticity.The tensile strength reaches 307(±8.52)MPa and the elongation is 12.73(±0.84)%.At this time,the curve of work hardening rate decreases smoothly and the degree of hardening is the lowest,and the amplitude of stress drop △σ_(p) in work softening test is the smallest with the increase of cycle times,which shows that the well coordination between work hardening and softening behavior has been achieved.Research has found that the combined effect of grain boundary strengthening and fine grain strengthening enhances the yield and tensile strength of magnesium sheets after three passes HP-ARB process at 350℃.This is attributed to the high degree of dislocation slip opening in the pyramidal surfaceand<c+a>,which not only coordinates the c-axis strain of the entire grain,but also promotes the slip transfer of dislocations in the fine-grained region,significantly improving the elongation of the sheets.This study provides a new idea for the forming and manufacturing of high performance magnesium alloy sheets.展开更多
To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s ...To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s aspect ratio on the microstructure,mechanical properties,work hardening and softening behaviors of Ti_(p)/Mg-5Zn-0.3Ca composites was investigated.The results indicated that the Ti_(p)could be elongated obviously after low-temperature extrusion,and the aspect ratio of which would reach to 13.7:1 as the extrusion temperature deceased to 140℃.Then the“Ti/Mg”layer-like structure was formed in the Ti_(p)/Mg-5Zn-0.3Ca composite.Accompanied with the elongation of Ti_(p),the dynamic recrystallized grains and dynamic precipitates were both refined significantly,however,the dynamic recrystallization rate changed a little.The elongated Ti_(p)endowed the Ti_(p)/Mg-5Zn-0.3Ca composites with better matching of strength and toughness without the sacrifice of elongation and bending strain.Both the work hardening rate and softening rate of Ti_(p)/Mg-5Zn-0.3Ca composites increased with the increasing aspect ratio of Ti_(p).The formation of“Ti/Mg”layer-like structure contributed to the redistribution of strain from large aggregations to a network-like distribution,which effectively suppresses the initiation and propagation of micro-cracks,thus enhancing the plasticity of the Ti_(p)/Mg-5Zn-0.3Ca composites.展开更多
This study investigated the relationships between human resource(HR)practices,employee psychological empowerment,employee innovative work behavior,and firm innovation capability in the context of the Information and C...This study investigated the relationships between human resource(HR)practices,employee psychological empowerment,employee innovative work behavior,and firm innovation capability in the context of the Information and Communication Technology(ICT)sector in Jordan.Employing the Social Exchange Theory(SET)as a guiding framework,this study explored how employee psychological empowerment and innovative work behavior mediated the influence of HR practices on a firm’s innovative capabilities.Drawing on extensive data collected from ICT organizations in Jordan,our analysis had several key findings.A significant positive correlation between HR practices and psychological empowerment was observed.Job design emerged as the most influential factor affecting psychological empowerment,whereas compensation had a weaker impact.Furthermore,we established that psychological empowerment significantly enhanced innovative work behavior,underscoring its role as a catalyst for innovative work behavior within the sector.Finally,our study supported the theory that psychological empowerment influenced a firms’innovation capabilities,emphasizing the pivotal role of employee empowerment in driving firm-level innovation in the Jordanian ICT sector.These findings provide insights for academic and practical audiences,clarifying how HR practices,employee psychological empowerment,and innovative work behavior collectively influenced firm innovation capability within the unique context of the Jordanian ICT sector.展开更多
Leader humility has emerged as an important topic in understanding the role of leadership in organizations in recent years.Though it was found to enhance subordinates’work performance and positive work behaviors,we a...Leader humility has emerged as an important topic in understanding the role of leadership in organizations in recent years.Though it was found to enhance subordinates’work performance and positive work behaviors,we are unaware of the psychological mechanism and boundary conditions underlying leader humility and employees’negative behaviors toward leaders.Drawing on social exchange theory and using a multistage sample including 273 employees and 55 supervisors in China,we demonstrated a negative indirect effect between leader humility and subordinates’counterproductive work behaviors toward supervisors(CWB-S)via interpersonal justice and trust in supervisor.Furthermore,we find that leader political skill moderates the effect of leader humility on interpersonal justice and trust in supervisor.The indirect effect of leader humility on subordinates’CWB-S through interpersonal justice is stronger when leader political skill is high,suggesting a moderated mediation model.Finally,we discuss the theoretical contributions and practical implications of this study,and highlight future directions for research on leader humility.展开更多
As a special taxonomy of personality,General Causality Orientations can be usefully characterized in terms of understanding the nature of causation of behavior.Researchers have used General Causality Orientations to e...As a special taxonomy of personality,General Causality Orientations can be usefully characterized in terms of understanding the nature of causation of behavior.Researchers have used General Causality Orientations to explain various organizational phenomena.In this article,we reviewed the literature to understand General Causality Orientations and pointed out the importance of predicting behaviors in the workplace.In accordance with the environmental and personality factors,General Causality Orientations and the Five-Factor Model were distinguished.Furthermore,it was discussed how General Causality Orientations may interpret work behaviors and some implications were given for organizations.展开更多
Based on the view of transformational leadership theory, the relationship between transformational leadership and the counterproductive work behavior of knowledge employee was researched. 221 valid questionnaires were...Based on the view of transformational leadership theory, the relationship between transformational leadership and the counterproductive work behavior of knowledge employee was researched. 221 valid questionnaires were obtained through the survey. Hierarchical regression analysis results showed that the virtue was significantly negative related to all the six dimensions of knowledge employee counterproductive work behavior, the vision incentive was significantly negative related to five dimensions of the knowledge employee counterproductive behavior except conservative intellectual behavior, the charisma was significantly negative related to five dimensions of the knowledge employee counterproductive work behavior except passive obedience behavior, personalized care was significantly negative related to five dimensions of the knowledge employee counterproductive behavior except immoral behavior. In short, transformational leadership was negatively related to the knowledge employee counterproductive work behavior.展开更多
The constant strain rate uniaxial compression tests were conducted in this paper for studying the work hardening behavior and revealing the underlying microstructure evolution involved in the plastic response of the n...The constant strain rate uniaxial compression tests were conducted in this paper for studying the work hardening behavior and revealing the underlying microstructure evolution involved in the plastic response of the nickel-based Inconel X-750 alloy. The work hardening rate versus true strain plots of Inconel X-750 alloy resembled that of low-stacking-fault energy （SFE） alloys with distinct four stages. The dislocations were found in the planar arrangements at a strain of 0.1 located at the onset of stage II, and the dislocation density was increased and the planar arrangement configuration was partially destroyed at a strain of 0.36 located in stage III. It was unexpected that deformation twins were observed at a strain of 0.69 located in stage IV although the alloy has been classified into materials with a higher SFE value. The result is different with a similar study, in which the deformation twins were absent in Ni-Cr-based alloy Inconel 625 even when the strain was as high as 0.65. It was deemed that the low level of solution strengthening favored the deformation of matrix and the activation of slip system for twining in Inconel X-750 alloy. Unlike the low-SFE alloys that the twins were always formed at the end of stage Ⅰ, the higher SFE delayed the twin formation to stage IV for Inconel X-750 alloy. The well- developed planar dislocation configuration gave rise to the stage Ⅱ with a slightly decreasing rate, the collapse of planar dislocation arrangements caused the occurrence of stage Ⅲ with an accelerated decreasing rate, and the twin formation led to the stage IV with a nearly constant work hardening rate.展开更多
To study the stress, deformation, and seepage pressure during the initial impoundment of the Jinping-I Arch Dam, monitoring analysis and numerical calculation were used in a dam behavior analysis that focused on the w...To study the stress, deformation, and seepage pressure during the initial impoundment of the Jinping-I Arch Dam, monitoring analysis and numerical calculation were used in a dam behavior analysis that focused on the working behavior of the dam during the late period of the initial impoundment up to the end of November 2014. The numerical calculation was performed based on feedback analysis of the deformation and stress of the arch dam through inversion of the elastic moduli(E) of the dam body and foundation, using a three-dimensional finite element model for the linear elastic material of the arch dam. The main monitoring indices presented insignificant changes in the late period of the initial impoundment, and the results of feedback analysis were consistent with monitoring results. Analysis results also show that the deformations of the dam body and dam foundation were within the design range; the dam stress distributions were normal, with values lower than the design control criteria; and the seepage flows through the dam body and dam foundation were lower than the design drainage capacity of the deep-well pump house, demonstrating that the Jinping-I Arch Dam was in good working condition, and the initial impoundment had been successfully completed. The results of the working behavior analysis of the Jinping-I hydropower project during the initial impoundment can provide references for safe operation of similar projects.展开更多
The metastable austenite was transformed to martensite by prestrain tension of SUS304 stainless steel to study the influence of transformed martensite on its subsequent work-hardening behavior under the uniaxial tensi...The metastable austenite was transformed to martensite by prestrain tension of SUS304 stainless steel to study the influence of transformed martensite on its subsequent work-hardening behavior under the uniaxial tensile condition. The X-ray diffractometer （XRD） was employed to detect the transformed martensite. Results showed that the volume fraction of transformed martensite increases with increasing prestrain. The pre-transformed martensite in the microstructure remarkably affects the deformation behavior of the steel, and the strength increases and the elongation decreases. The work-hardening curve of prestrained specimens observably changes with true strain. The work-hardening exponent n of stainless steel decreases with the increase of pre-transformed martensite. The achievement is a significant contribution to the process design during pressing.展开更多
To examine the influence of grain boundary engineering(GBE)on the work hardening behavior,the tensile tests were carried out on the non-GBE and GBE AL6XN super-austenitic stainless steel(ASS)samples with a comparable ...To examine the influence of grain boundary engineering(GBE)on the work hardening behavior,the tensile tests were carried out on the non-GBE and GBE AL6XN super-austenitic stainless steel(ASS)samples with a comparable grain size at two strain rates of 10^(-2)s^(-1)and 10^(-4)s^(-1).The evolution of deformation microstructures was revealed by transmission electron microscopy(TEM)and quasi-in situ electron backscatter diffraction(EBSD)observations.The results show that the influence of GBE on the mechanical properties of AL6XN super-ASS is mainly manifested in the change of work hardening behavior.At the early stage of plastic deformation,GBE samples show a slightly lowered work hardening rate,since the special grain boundaries(SBs)of a high fraction induce a higher dislocation free path and a weaker back stress;however,with increasing plastic deformation amount,the work hardening rate of GBE samples gradually surpasses that of non-GBE samples due to the better capacity of maintainable work hardening that is profited from the inhibited dislocation annihilation by SBs.In a word,the enhanced capacity of sustained work hardening effectively postpones the appearance of necking point and thus efficaciously ameliorates the ductility of GBE samples under the premise of little changes in yield strength and ultimate tensile strength.展开更多
In order to analyze the thermal field and thermal contour of work roll in finishing trains of hot rolling in rolling process, a quasi two-dimension implicit finite difference model is developed. To improve the calcula...In order to analyze the thermal field and thermal contour of work roll in finishing trains of hot rolling in rolling process, a quasi two-dimension implicit finite difference model is developed. To improve the calculating speed and precision, some special solutions are introduced, including the development of this model, the simplification of boundary conditions and the computation of heat transfer coefficients. The results show that these solutions of thermal behaviors of work roll are very much efficient and the model can be used as an on-line profile and fatness control model of large industrial mills.展开更多
Job crafting (JC) is a form of proactive behavior and refers to the initiatives employees that could take to change their tasks or other job characteristics to achieve the best person-job fit. JC consists of six dimen...Job crafting (JC) is a form of proactive behavior and refers to the initiatives employees that could take to change their tasks or other job characteristics to achieve the best person-job fit. JC consists of six dimensions: seeking structural and social job resources, as well as challenges, hindering job demands, optimizing job demands, and delegating tasks. The aim of the present study was to explore the impact of self-efficacy and work engagement on healthcare professionals’ (HP) proactive behavior. A convenience sample of 295 HP working in Primary and Secondary healthcare structures of Northern Greece completed a questionnaire that included: 1) demographic/occupational characteristics, 2) the Job Crafting Scale, 3) the Generalized Self-Efficacy Scale (GSE) and 4) the Utrecht Work Engagement Scale (UWES). Increased age was found to be associated with decreased levels of seeking social job resources (p < 0.01). Education level was positively associated with increased levels of seeking structural job resources (p < 0.01), seeking challenges (p < 0.05), and optimizing job demands (p < 0.05), while job position was found to be negatively related to delegating tasks (p < 0.01). Self-efficacy was positively associated with increased levels of seeking structural resources (p < 0.001), challenges (p < 0.001), and increased levels of optimizing job demands (p < 0.001), while it was positively associated with decreased levels of delegating tasks (p < 0.05). In addition, increased work engagement was found to be associated with increased levels of seeking social job resources (p < 0.05), challenges (p < 0.01), and optimizing job demands (p < 0.01). Findings highlight the importance of self-efficacy, work engagement and individual characteristics in the realization of a resourceful work environment and HP’ adjustment in the organization. Thus, interventions that promote HP’ JC proactive behaviors should be encouraged.展开更多
Work-team has emerged as an important unit composi ng the organization today. The concepts relating to the properties of team-role t hat fit with today’s business environment have attracted much attention from the th...Work-team has emerged as an important unit composi ng the organization today. The concepts relating to the properties of team-role t hat fit with today’s business environment have attracted much attention from the theorists and researchers. A team having a balanced composition of team-ro les is called a balanced team. Theoretically, a balanced team usually renders a better team performance. Therefore, to improve the performance of the team, mana gement needs to ensure that their work teams are composed of appropriate team me mbers with complementary skills, playing different roles, together forming a bal anced team. However, in certain situation, a balanced team can hardly be formed. For example , companies in Hong Kong are mostly the small-to-medium sized enterprises. The number of team-members is usually smaller than the required number for formula ting a balanced team. Also, as team members are required to travel often across borders, stable team can hardly be maintained. To resolve this problem, a different paradigm of team-role prevails here. Team -members autonomously supplant the roles of those missing members. We call this phenomenon the kinetic team role behavior. By using the methodology adopted from psychotherapy study, we propose a way to investigate this interesting and important characteristics of team-role.展开更多
Purpose: This study aims to explore the relationships between different facets of work task and selection and query-related behavior.Design/methodology/approach:An experiment was conducted to explore the issue. The re...Purpose: This study aims to explore the relationships between different facets of work task and selection and query-related behavior.Design/methodology/approach:An experiment was conducted to explore the issue. The researcher recruited 24 participants and assigned six simulated work task situations to each of them. Each experiment lasted around 2 hours and was recorded by the software tool Morae.Findings: Time(frequency) and time(length) are more closely related to user’s selection and query-related behavior compared to the facet ‘process’ of work task. Knowledge level of work task topic, degree of work task difficulty, and subjective work task complexity are significantly correlated with selection and query-related behavior. Work task difficulty and work task complexity are different concepts. Subjective work task complexity, work task difficulty, and knowledge of work task topic are significantly correlated with user’s selection and query-related behavior.Research limitations/implications: The limitations of this study include a small sample size,limited work task situations, and possible spurious relationships. This study has implications in informing task-based information seeking/search/retrieval research and interactive information retrieval(IIR) systems design.Originality/values: Previous studies usually did not touch upon how different facets of work tasks affected interactive activities. Some studies examining task complexity and information behavior were concerned with how work tasks affect users’ behavior at information-seeking level, rather than at information search level. This study makes contribution to interactive information retrieval,task-based information search and retrieval, and personalization of IR.展开更多
The management of eating behavior plays an important role in health maintenance. In this study, we investigated the relationship between eating behavior and effortful control in female young adults. Participants compl...The management of eating behavior plays an important role in health maintenance. In this study, we investigated the relationship between eating behavior and effortful control in female young adults. Participants completed the questionnaire measures of effortful control and eating behaviors and Stroop cognitive interference task. The results showed that restrained eating was positively correlated with activation control;emotional eating was negatively correlated with inhibitory control and attentional control;external eating was negatively correlated with inhibitory, activation, and attentional control. The scores for activation control and restrained eating were higher for participants with a low Stroop error rate than for those with a high Stroop error rate. These results indicate that restrained eating has a different association with effortful control than doing emotional and external eating.展开更多
基金supported by the Natural Science Foundation of Heilongjiang Province(No.JQ2022E004).
文摘In this paper,the work hardening and softening behavior of AZ31 magnesium alloy sheets by hard plate accumulative roll bonding(HP-ARB)process in a specific temperature range was studied for the first time,and the cyclic stress relaxation test,EBSD,TEM and other characterization methods were used.When the rolling temperature is 350℃,the grain size of magnesium sheets is refined to 4.32(±0.36)μm on average,and it shows an excellent combination of strength and plasticity.The tensile strength reaches 307(±8.52)MPa and the elongation is 12.73(±0.84)%.At this time,the curve of work hardening rate decreases smoothly and the degree of hardening is the lowest,and the amplitude of stress drop △σ_(p) in work softening test is the smallest with the increase of cycle times,which shows that the well coordination between work hardening and softening behavior has been achieved.Research has found that the combined effect of grain boundary strengthening and fine grain strengthening enhances the yield and tensile strength of magnesium sheets after three passes HP-ARB process at 350℃.This is attributed to the high degree of dislocation slip opening in the pyramidal surfaceand<c+a>,which not only coordinates the c-axis strain of the entire grain,but also promotes the slip transfer of dislocations in the fine-grained region,significantly improving the elongation of the sheets.This study provides a new idea for the forming and manufacturing of high performance magnesium alloy sheets.
基金supported by the“National Natural Science Foundation of China”(Grants.52271109 and 52001223)Support from the“National Key Research and Development Program for Young Scientists”(Grant.2021YFB3703300)+1 种基金the Major Special Plan for Science and Technology in Shanxi Province(202201050201012)the Special Fund Project for Guiding Local Science and Technology Development by the Central Government(Grant.YDZJSX2021B019)。
文摘To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s aspect ratio on the microstructure,mechanical properties,work hardening and softening behaviors of Ti_(p)/Mg-5Zn-0.3Ca composites was investigated.The results indicated that the Ti_(p)could be elongated obviously after low-temperature extrusion,and the aspect ratio of which would reach to 13.7:1 as the extrusion temperature deceased to 140℃.Then the“Ti/Mg”layer-like structure was formed in the Ti_(p)/Mg-5Zn-0.3Ca composite.Accompanied with the elongation of Ti_(p),the dynamic recrystallized grains and dynamic precipitates were both refined significantly,however,the dynamic recrystallization rate changed a little.The elongated Ti_(p)endowed the Ti_(p)/Mg-5Zn-0.3Ca composites with better matching of strength and toughness without the sacrifice of elongation and bending strain.Both the work hardening rate and softening rate of Ti_(p)/Mg-5Zn-0.3Ca composites increased with the increasing aspect ratio of Ti_(p).The formation of“Ti/Mg”layer-like structure contributed to the redistribution of strain from large aggregations to a network-like distribution,which effectively suppresses the initiation and propagation of micro-cracks,thus enhancing the plasticity of the Ti_(p)/Mg-5Zn-0.3Ca composites.
文摘This study investigated the relationships between human resource(HR)practices,employee psychological empowerment,employee innovative work behavior,and firm innovation capability in the context of the Information and Communication Technology(ICT)sector in Jordan.Employing the Social Exchange Theory(SET)as a guiding framework,this study explored how employee psychological empowerment and innovative work behavior mediated the influence of HR practices on a firm’s innovative capabilities.Drawing on extensive data collected from ICT organizations in Jordan,our analysis had several key findings.A significant positive correlation between HR practices and psychological empowerment was observed.Job design emerged as the most influential factor affecting psychological empowerment,whereas compensation had a weaker impact.Furthermore,we established that psychological empowerment significantly enhanced innovative work behavior,underscoring its role as a catalyst for innovative work behavior within the sector.Finally,our study supported the theory that psychological empowerment influenced a firms’innovation capabilities,emphasizing the pivotal role of employee empowerment in driving firm-level innovation in the Jordanian ICT sector.These findings provide insights for academic and practical audiences,clarifying how HR practices,employee psychological empowerment,and innovative work behavior collectively influenced firm innovation capability within the unique context of the Jordanian ICT sector.
基金National Natural Science Foundation of China(project code:7164001571772176)Yuyou Talent Program of NCUT,and the 2019 PhD Joint Training Scholarship of Renmin Business School.
文摘Leader humility has emerged as an important topic in understanding the role of leadership in organizations in recent years.Though it was found to enhance subordinates’work performance and positive work behaviors,we are unaware of the psychological mechanism and boundary conditions underlying leader humility and employees’negative behaviors toward leaders.Drawing on social exchange theory and using a multistage sample including 273 employees and 55 supervisors in China,we demonstrated a negative indirect effect between leader humility and subordinates’counterproductive work behaviors toward supervisors(CWB-S)via interpersonal justice and trust in supervisor.Furthermore,we find that leader political skill moderates the effect of leader humility on interpersonal justice and trust in supervisor.The indirect effect of leader humility on subordinates’CWB-S through interpersonal justice is stronger when leader political skill is high,suggesting a moderated mediation model.Finally,we discuss the theoretical contributions and practical implications of this study,and highlight future directions for research on leader humility.
基金ACKNOWLEDGEMENTS We especially thank the National Science Foundation of China(70771009,71071017)the Fundamental Research Funds for the Central Universities(FRF-BR-09-019)for supporting this research.
文摘As a special taxonomy of personality,General Causality Orientations can be usefully characterized in terms of understanding the nature of causation of behavior.Researchers have used General Causality Orientations to explain various organizational phenomena.In this article,we reviewed the literature to understand General Causality Orientations and pointed out the importance of predicting behaviors in the workplace.In accordance with the environmental and personality factors,General Causality Orientations and the Five-Factor Model were distinguished.Furthermore,it was discussed how General Causality Orientations may interpret work behaviors and some implications were given for organizations.
文摘Based on the view of transformational leadership theory, the relationship between transformational leadership and the counterproductive work behavior of knowledge employee was researched. 221 valid questionnaires were obtained through the survey. Hierarchical regression analysis results showed that the virtue was significantly negative related to all the six dimensions of knowledge employee counterproductive work behavior, the vision incentive was significantly negative related to five dimensions of the knowledge employee counterproductive behavior except conservative intellectual behavior, the charisma was significantly negative related to five dimensions of the knowledge employee counterproductive work behavior except passive obedience behavior, personalized care was significantly negative related to five dimensions of the knowledge employee counterproductive behavior except immoral behavior. In short, transformational leadership was negatively related to the knowledge employee counterproductive work behavior.
文摘The constant strain rate uniaxial compression tests were conducted in this paper for studying the work hardening behavior and revealing the underlying microstructure evolution involved in the plastic response of the nickel-based Inconel X-750 alloy. The work hardening rate versus true strain plots of Inconel X-750 alloy resembled that of low-stacking-fault energy （SFE） alloys with distinct four stages. The dislocations were found in the planar arrangements at a strain of 0.1 located at the onset of stage II, and the dislocation density was increased and the planar arrangement configuration was partially destroyed at a strain of 0.36 located in stage III. It was unexpected that deformation twins were observed at a strain of 0.69 located in stage IV although the alloy has been classified into materials with a higher SFE value. The result is different with a similar study, in which the deformation twins were absent in Ni-Cr-based alloy Inconel 625 even when the strain was as high as 0.65. It was deemed that the low level of solution strengthening favored the deformation of matrix and the activation of slip system for twining in Inconel X-750 alloy. Unlike the low-SFE alloys that the twins were always formed at the end of stage Ⅰ, the higher SFE delayed the twin formation to stage IV for Inconel X-750 alloy. The well- developed planar dislocation configuration gave rise to the stage Ⅱ with a slightly decreasing rate, the collapse of planar dislocation arrangements caused the occurrence of stage Ⅲ with an accelerated decreasing rate, and the twin formation led to the stage IV with a nearly constant work hardening rate.
基金supported by the National Key Technology Support Program(Grant No.2013BAB05B05)
文摘To study the stress, deformation, and seepage pressure during the initial impoundment of the Jinping-I Arch Dam, monitoring analysis and numerical calculation were used in a dam behavior analysis that focused on the working behavior of the dam during the late period of the initial impoundment up to the end of November 2014. The numerical calculation was performed based on feedback analysis of the deformation and stress of the arch dam through inversion of the elastic moduli(E) of the dam body and foundation, using a three-dimensional finite element model for the linear elastic material of the arch dam. The main monitoring indices presented insignificant changes in the late period of the initial impoundment, and the results of feedback analysis were consistent with monitoring results. Analysis results also show that the deformations of the dam body and dam foundation were within the design range; the dam stress distributions were normal, with values lower than the design control criteria; and the seepage flows through the dam body and dam foundation were lower than the design drainage capacity of the deep-well pump house, demonstrating that the Jinping-I Arch Dam was in good working condition, and the initial impoundment had been successfully completed. The results of the working behavior analysis of the Jinping-I hydropower project during the initial impoundment can provide references for safe operation of similar projects.
基金Item Sponsored by National Natural Science Foundation of China (50675128 50975166)
文摘The metastable austenite was transformed to martensite by prestrain tension of SUS304 stainless steel to study the influence of transformed martensite on its subsequent work-hardening behavior under the uniaxial tensile condition. The X-ray diffractometer （XRD） was employed to detect the transformed martensite. Results showed that the volume fraction of transformed martensite increases with increasing prestrain. The pre-transformed martensite in the microstructure remarkably affects the deformation behavior of the steel, and the strength increases and the elongation decreases. The work-hardening curve of prestrained specimens observably changes with true strain. The work-hardening exponent n of stainless steel decreases with the increase of pre-transformed martensite. The achievement is a significant contribution to the process design during pressing.
基金financially supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.51871048 and 52171108。
文摘To examine the influence of grain boundary engineering(GBE)on the work hardening behavior,the tensile tests were carried out on the non-GBE and GBE AL6XN super-austenitic stainless steel(ASS)samples with a comparable grain size at two strain rates of 10^(-2)s^(-1)and 10^(-4)s^(-1).The evolution of deformation microstructures was revealed by transmission electron microscopy(TEM)and quasi-in situ electron backscatter diffraction(EBSD)observations.The results show that the influence of GBE on the mechanical properties of AL6XN super-ASS is mainly manifested in the change of work hardening behavior.At the early stage of plastic deformation,GBE samples show a slightly lowered work hardening rate,since the special grain boundaries(SBs)of a high fraction induce a higher dislocation free path and a weaker back stress;however,with increasing plastic deformation amount,the work hardening rate of GBE samples gradually surpasses that of non-GBE samples due to the better capacity of maintainable work hardening that is profited from the inhibited dislocation annihilation by SBs.In a word,the enhanced capacity of sustained work hardening effectively postpones the appearance of necking point and thus efficaciously ameliorates the ductility of GBE samples under the premise of little changes in yield strength and ultimate tensile strength.
文摘In order to analyze the thermal field and thermal contour of work roll in finishing trains of hot rolling in rolling process, a quasi two-dimension implicit finite difference model is developed. To improve the calculating speed and precision, some special solutions are introduced, including the development of this model, the simplification of boundary conditions and the computation of heat transfer coefficients. The results show that these solutions of thermal behaviors of work roll are very much efficient and the model can be used as an on-line profile and fatness control model of large industrial mills.
文摘Job crafting (JC) is a form of proactive behavior and refers to the initiatives employees that could take to change their tasks or other job characteristics to achieve the best person-job fit. JC consists of six dimensions: seeking structural and social job resources, as well as challenges, hindering job demands, optimizing job demands, and delegating tasks. The aim of the present study was to explore the impact of self-efficacy and work engagement on healthcare professionals’ (HP) proactive behavior. A convenience sample of 295 HP working in Primary and Secondary healthcare structures of Northern Greece completed a questionnaire that included: 1) demographic/occupational characteristics, 2) the Job Crafting Scale, 3) the Generalized Self-Efficacy Scale (GSE) and 4) the Utrecht Work Engagement Scale (UWES). Increased age was found to be associated with decreased levels of seeking social job resources (p < 0.01). Education level was positively associated with increased levels of seeking structural job resources (p < 0.01), seeking challenges (p < 0.05), and optimizing job demands (p < 0.05), while job position was found to be negatively related to delegating tasks (p < 0.01). Self-efficacy was positively associated with increased levels of seeking structural resources (p < 0.001), challenges (p < 0.001), and increased levels of optimizing job demands (p < 0.001), while it was positively associated with decreased levels of delegating tasks (p < 0.05). In addition, increased work engagement was found to be associated with increased levels of seeking social job resources (p < 0.05), challenges (p < 0.01), and optimizing job demands (p < 0.01). Findings highlight the importance of self-efficacy, work engagement and individual characteristics in the realization of a resourceful work environment and HP’ adjustment in the organization. Thus, interventions that promote HP’ JC proactive behaviors should be encouraged.
文摘Work-team has emerged as an important unit composi ng the organization today. The concepts relating to the properties of team-role t hat fit with today’s business environment have attracted much attention from the theorists and researchers. A team having a balanced composition of team-ro les is called a balanced team. Theoretically, a balanced team usually renders a better team performance. Therefore, to improve the performance of the team, mana gement needs to ensure that their work teams are composed of appropriate team me mbers with complementary skills, playing different roles, together forming a bal anced team. However, in certain situation, a balanced team can hardly be formed. For example , companies in Hong Kong are mostly the small-to-medium sized enterprises. The number of team-members is usually smaller than the required number for formula ting a balanced team. Also, as team members are required to travel often across borders, stable team can hardly be maintained. To resolve this problem, a different paradigm of team-role prevails here. Team -members autonomously supplant the roles of those missing members. We call this phenomenon the kinetic team role behavior. By using the methodology adopted from psychotherapy study, we propose a way to investigate this interesting and important characteristics of team-role.
基金sponsored by National Social Science Foundation of China(Grant No. 11BTQ009)
文摘Purpose: This study aims to explore the relationships between different facets of work task and selection and query-related behavior.Design/methodology/approach:An experiment was conducted to explore the issue. The researcher recruited 24 participants and assigned six simulated work task situations to each of them. Each experiment lasted around 2 hours and was recorded by the software tool Morae.Findings: Time(frequency) and time(length) are more closely related to user’s selection and query-related behavior compared to the facet ‘process’ of work task. Knowledge level of work task topic, degree of work task difficulty, and subjective work task complexity are significantly correlated with selection and query-related behavior. Work task difficulty and work task complexity are different concepts. Subjective work task complexity, work task difficulty, and knowledge of work task topic are significantly correlated with user’s selection and query-related behavior.Research limitations/implications: The limitations of this study include a small sample size,limited work task situations, and possible spurious relationships. This study has implications in informing task-based information seeking/search/retrieval research and interactive information retrieval(IIR) systems design.Originality/values: Previous studies usually did not touch upon how different facets of work tasks affected interactive activities. Some studies examining task complexity and information behavior were concerned with how work tasks affect users’ behavior at information-seeking level, rather than at information search level. This study makes contribution to interactive information retrieval,task-based information search and retrieval, and personalization of IR.
文摘The management of eating behavior plays an important role in health maintenance. In this study, we investigated the relationship between eating behavior and effortful control in female young adults. Participants completed the questionnaire measures of effortful control and eating behaviors and Stroop cognitive interference task. The results showed that restrained eating was positively correlated with activation control;emotional eating was negatively correlated with inhibitory control and attentional control;external eating was negatively correlated with inhibitory, activation, and attentional control. The scores for activation control and restrained eating were higher for participants with a low Stroop error rate than for those with a high Stroop error rate. These results indicate that restrained eating has a different association with effortful control than doing emotional and external eating.
