The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its ther...The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its thermodynamic properties make it a fluid of choice in the efficient use of energy at low and medium temperatures in engine cycles. However, the performance of transcritical CO2 cycles weakens under high temperature and pressure conditions, especially in refrigeration systems;On the other hand, this disadvantage becomes rather interesting in engine cycles where CO2 can be used as an alternative to the organic working fluid in small and medium-sized electrical systems for low quality or waste heat sources. In order to improve the performance of systems operating with CO2 in the field of refrigeration and electricity production, research has made it possible to develop several concepts, of which this article deals with a review of the state of the art, followed by analyzes in-depth and critical of the various developments to the most recent modifications in these fields. Detailed discussions on the performance and technical characteristics of the different evolutions are also highlighted as well as the factors affecting the overall performance of the systems studied. Finally, perspectives on the future development of the use of CO2 in these different cycles are presented.展开更多
There are some special spaces in which there is no air conditioning or the people are in move,thus exposing people to a hot environment.In this study,portable cooling systems were proposed and their effects on thermal...There are some special spaces in which there is no air conditioning or the people are in move,thus exposing people to a hot environment.In this study,portable cooling systems were proposed and their effects on thermal comfort and work performance were investigated at an air temperature of 32°C.Four conditions were established:cool air towards breathing zone(A),chest and back cooling(B)#combined cooling(C)and no cooling(D).Twenty-eight subjects were exposed to the four conditions in a counterbalanced order.During each exposure they performed tasks and made subjective assessments,while multiple physiological parameters were measured.Compared with no cooling(D),cool air towards breathing zone(A)and chest and back cooling(B)improved work performance by 17.5%and 19.25%,respectively,while decreased the subjects'thermal sensation,skin temperature,and heart rate.When the two cooling systems were combined(C),larger improvements in thermal comfort and work performance were achieved than no cooling(D);the mean thermal sensation rating decreased from 2.4 to 0.7;work performance increased by up to 33%,and physiological parameters including skin temperature,pulse,heart rate and salivary alpha-amylase significantly decreased.The present results suggest that the proposed portable cooling systems could maintain thermal comfort and work performance in a hot environment,while potentially improve air quality for some special spaces.展开更多
This study investigates the functioning mechanisms of how high performance work systems （HPWS） affect organizational performance. We propose that （HPWS） can positively affect organizational performance through the...This study investigates the functioning mechanisms of how high performance work systems （HPWS） affect organizational performance. We propose that （HPWS） can positively affect organizational performance through the mediating role of entrepreneurial orientation. An organization with high performance work systems can perform better if it enjoys high level of organizational learning. We design and administer a survey questionnaire to high-level executives or founders of companies from manufacturing and service industries and receive 176 valid responses. The results of the empirical data indicate that the relationship between high performance work systems and corporate performance is more positive when organizational learning is stronger. Entrepreneurial orientation partially mediates the relationship between high performance work systems and organizational performance. This study opens new research avenues by extending and incorporating explanations and predictions of HPWS and entrepreneurial orientation, two areas that largely have been considered independently of each other. Implications for practice and directions for future research are provided.展开更多
Employee creativity is both the core element of a firm＇s innovation capabilities and the sources for its growth. To improve an organization＇s ability to innovate, it is necessary to improve the creativity of its emp...Employee creativity is both the core element of a firm＇s innovation capabilities and the sources for its growth. To improve an organization＇s ability to innovate, it is necessary to improve the creativity of its employees. Based on theories from strategic human resource management, creativity and organizational learning, this paper investigates the relationship between high performance work systems and employee creativity and explores the role knowledge sharing plays in their relationship. A questionnaire is designed and administered to a group of part-time executive students in the winter of 2012. Two hundred students are invited to answer the survey questions with 117 valid responses. Data are collected and processed by using statistical regressions. The empirical findings reveal that high performance work systems positively affect knowledge sharing and employee creativity. Knowledge sharing plays a mediating role in the relationship between high performance work systems and employee creativity. Implications for practice and future research are discussed.展开更多
This study examines the key human resources factors that affect volunteers＇ service performance from the perspectives of volunteers and managers in the Beijing Summer Olympic Games of 2008. Survey data were collected...This study examines the key human resources factors that affect volunteers＇ service performance from the perspectives of volunteers and managers in the Beijing Summer Olympic Games of 2008. Survey data were collected from 1,727 volunteers and 243 managers at the Beijing Olympics test events held at 10 venues between November 2007 and April 2008. Regression analyses and a moderation test were combined to test the hypotheses. A set of high performance work systems （HPWS） for volunteers in the Beijing Summer Olympic Games were developed which include performance management, training, recognition, teamwork and volunteer participation. Volunteer HPWS were positively related to psychological empowerment, which was in turn positively related to service recovery performance. Moreover, transformational leadership moderates the relationship between volunteer HPWS and psychological empowerment in such a way that the relationship is stronger when transformational leadership is at a higher level than when it is at a lower level.Implications and limitations were also discussed.展开更多
This research paper investigates the relationship between high-performance work systems(HPWS),organisational memory,and employee in-role performance,focus-ing on the direct impact of HPWS on different dimensions of or...This research paper investigates the relationship between high-performance work systems(HPWS),organisational memory,and employee in-role performance,focus-ing on the direct impact of HPWS on different dimensions of organisational memory and employee in-role performance,as well as the mediating role of organisational memory in this relationship.Utilizing a sample of employees working in the tele-communications industry,the study employed structural equation modelling to ana-lyse the relationships among HPWS,organisational memory,and employee in-role performance.The findings revealed that HPWS positively influence all three dimen-sions of organisational memory and employee in-role performance,with organisa-tional memory partially mediating the relationship between HPWS and employee in-role performance.However,the study was limited to the telecommunications industry and Dhofar region and did not examine the potential moderating effects of individual-level or contextual factors on the relationships among HPWS,organisa-tional memory,and employee in-role performance.The study offers practical impli-cations for organizations seeking to improve employee performance and overall effectiveness by highlighting the importance of implementing high-performance work systems and managing organisational memory effectively.This study contrib-utes to the literature on the relationships among HPWS,organisational memory,and employee in-role performance,providing valuable insights into the dynamics of organisational effectiveness.展开更多
文摘The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its thermodynamic properties make it a fluid of choice in the efficient use of energy at low and medium temperatures in engine cycles. However, the performance of transcritical CO2 cycles weakens under high temperature and pressure conditions, especially in refrigeration systems;On the other hand, this disadvantage becomes rather interesting in engine cycles where CO2 can be used as an alternative to the organic working fluid in small and medium-sized electrical systems for low quality or waste heat sources. In order to improve the performance of systems operating with CO2 in the field of refrigeration and electricity production, research has made it possible to develop several concepts, of which this article deals with a review of the state of the art, followed by analyzes in-depth and critical of the various developments to the most recent modifications in these fields. Detailed discussions on the performance and technical characteristics of the different evolutions are also highlighted as well as the factors affecting the overall performance of the systems studied. Finally, perspectives on the future development of the use of CO2 in these different cycles are presented.
基金This work was supported by the National Natural Science Foundation of China(No.51778359 and No.51478260)the State Key Laboratory of Air Conditioning Equipment and System Energy Conservation(No.ACSKL2018KT04)。
文摘There are some special spaces in which there is no air conditioning or the people are in move,thus exposing people to a hot environment.In this study,portable cooling systems were proposed and their effects on thermal comfort and work performance were investigated at an air temperature of 32°C.Four conditions were established:cool air towards breathing zone(A),chest and back cooling(B)#combined cooling(C)and no cooling(D).Twenty-eight subjects were exposed to the four conditions in a counterbalanced order.During each exposure they performed tasks and made subjective assessments,while multiple physiological parameters were measured.Compared with no cooling(D),cool air towards breathing zone(A)and chest and back cooling(B)improved work performance by 17.5%and 19.25%,respectively,while decreased the subjects'thermal sensation,skin temperature,and heart rate.When the two cooling systems were combined(C),larger improvements in thermal comfort and work performance were achieved than no cooling(D);the mean thermal sensation rating decreased from 2.4 to 0.7;work performance increased by up to 33%,and physiological parameters including skin temperature,pulse,heart rate and salivary alpha-amylase significantly decreased.The present results suggest that the proposed portable cooling systems could maintain thermal comfort and work performance in a hot environment,while potentially improve air quality for some special spaces.
文摘This study investigates the functioning mechanisms of how high performance work systems （HPWS） affect organizational performance. We propose that （HPWS） can positively affect organizational performance through the mediating role of entrepreneurial orientation. An organization with high performance work systems can perform better if it enjoys high level of organizational learning. We design and administer a survey questionnaire to high-level executives or founders of companies from manufacturing and service industries and receive 176 valid responses. The results of the empirical data indicate that the relationship between high performance work systems and corporate performance is more positive when organizational learning is stronger. Entrepreneurial orientation partially mediates the relationship between high performance work systems and organizational performance. This study opens new research avenues by extending and incorporating explanations and predictions of HPWS and entrepreneurial orientation, two areas that largely have been considered independently of each other. Implications for practice and directions for future research are provided.
文摘Employee creativity is both the core element of a firm＇s innovation capabilities and the sources for its growth. To improve an organization＇s ability to innovate, it is necessary to improve the creativity of its employees. Based on theories from strategic human resource management, creativity and organizational learning, this paper investigates the relationship between high performance work systems and employee creativity and explores the role knowledge sharing plays in their relationship. A questionnaire is designed and administered to a group of part-time executive students in the winter of 2012. Two hundred students are invited to answer the survey questions with 117 valid responses. Data are collected and processed by using statistical regressions. The empirical findings reveal that high performance work systems positively affect knowledge sharing and employee creativity. Knowledge sharing plays a mediating role in the relationship between high performance work systems and employee creativity. Implications for practice and future research are discussed.
文摘This study examines the key human resources factors that affect volunteers＇ service performance from the perspectives of volunteers and managers in the Beijing Summer Olympic Games of 2008. Survey data were collected from 1,727 volunteers and 243 managers at the Beijing Olympics test events held at 10 venues between November 2007 and April 2008. Regression analyses and a moderation test were combined to test the hypotheses. A set of high performance work systems （HPWS） for volunteers in the Beijing Summer Olympic Games were developed which include performance management, training, recognition, teamwork and volunteer participation. Volunteer HPWS were positively related to psychological empowerment, which was in turn positively related to service recovery performance. Moreover, transformational leadership moderates the relationship between volunteer HPWS and psychological empowerment in such a way that the relationship is stronger when transformational leadership is at a higher level than when it is at a lower level.Implications and limitations were also discussed.
文摘This research paper investigates the relationship between high-performance work systems(HPWS),organisational memory,and employee in-role performance,focus-ing on the direct impact of HPWS on different dimensions of organisational memory and employee in-role performance,as well as the mediating role of organisational memory in this relationship.Utilizing a sample of employees working in the tele-communications industry,the study employed structural equation modelling to ana-lyse the relationships among HPWS,organisational memory,and employee in-role performance.The findings revealed that HPWS positively influence all three dimen-sions of organisational memory and employee in-role performance,with organisa-tional memory partially mediating the relationship between HPWS and employee in-role performance.However,the study was limited to the telecommunications industry and Dhofar region and did not examine the potential moderating effects of individual-level or contextual factors on the relationships among HPWS,organisa-tional memory,and employee in-role performance.The study offers practical impli-cations for organizations seeking to improve employee performance and overall effectiveness by highlighting the importance of implementing high-performance work systems and managing organisational memory effectively.This study contrib-utes to the literature on the relationships among HPWS,organisational memory,and employee in-role performance,providing valuable insights into the dynamics of organisational effectiveness.
