This review delved into the intricate relationship between circadian clocks and physiological processes,emphasizing their critical role in maintaining homeo-stasis.Orchestrated by interlocked clock genes,the circadian...This review delved into the intricate relationship between circadian clocks and physiological processes,emphasizing their critical role in maintaining homeo-stasis.Orchestrated by interlocked clock genes,the circadian timekeeping system regulates fundamental processes like the sleep-wake cycle,energy metabolism,immune function,and cell proliferation.The central oscillator in the hypothalamic suprachiasmatic nucleus synchronizes with light-dark cycles,while peripheral tissue clocks are influenced by cues such as feeding times.Circadian disruption,linked to modern lifestyle factors like night shift work,correlates with adverse health outcomes,including metabolic syndrome,cardiovascular diseases,infec-tions,and cancer.We explored the molecular mechanisms of circadian clock genes and their impact on metabolic disorders and cancer pathogenesis.Specific associ-ations between circadian disruption and endocrine tumors,spanning breast,ovarian,testicular,prostate,thyroid,pituitary,and adrenal gland cancers,are highlighted.Shift work is associated with increased breast cancer risk,with PER genes influencing tumor progression and drug resistance.CLOCK gene expression correlates with cisplatin resistance in ovarian cancer,while factors like aging and intermittent fasting affect prostate cancer.Our review underscored the intricate interplay between circadian rhythms and cancer,involving the regulation of the cell cycle,DNA repair,metabolism,immune function,and the tumor microenvir-onment.We advocated for integrating biological timing into clinical consider-ations for personalized healthcare,proposing that understanding these connec-tions could lead to novel therapeutic approaches.Evidence supports circadian rhythm-focused therapies,particularly chronotherapy,for treating endocrine tumors.Our review called for further research to uncover detailed connections between circadian clocks and cancer,providing essential insights for targeted treatments.We emphasized the importance of public health interventions to mitigate lifestyle-related circadian disruptions and underscored the critical role of circadian rhythms in disease mechanisms and therapeutic interventions.展开更多
Objective:The aim of the study was to evaluate the quality of sleep in nurses performing shift work in therapeutic and surgical depar tments and to establish possible relationships between level of blood pressure(BP)a...Objective:The aim of the study was to evaluate the quality of sleep in nurses performing shift work in therapeutic and surgical depar tments and to establish possible relationships between level of blood pressure(BP)and quality of sleep.Methods:A total of 20 nurses of the therapeutic depar tments and 20 nurses of the surgical depar tments were enrolled in the study.Sleep quality was assessed using the Pittsburgh Sleep Quality Index(PSQI).BP was measured according to the standard protocol using the Korotkoff method;a sphygmomanometer was used for this twice with an interval of 2 min between 10:00 a.m.and 10:30 a.m.The average value for the 2 indicators was calculated.The diagnosis of essential ar terial hyper tension(AH)was established according to the recommendations of the European Association of Cardiology and the European Association of Hypertension(2018).Results:The overall assessment of the sleep quality of the nurses involved in shift work indicates poor sleep quality;this was true in respondents of both the surgical and therapeutic profiles.However,it was observed that the quality of sleep was significantly lower in nurses of the therapeutic departments.Moreover,poor sleep quality was associated with AH,which was diagnosed in 65%of the nurses of the therapeutic departments and 45%of the nurses of the surgical departments,that is,in almost all of the subjects.Herewith,in the nurses of the therapeutic departments,the level of systolic BP exceeded that of the nurses of the surgical departments.Conclusions:Poor sleep quality is a significant risk factor for AH development and is relevant to nurses performing shift work.Additional clinical studies should be conducted to better understand the mechanisms underlying such adverse cardiometabolic outcomes associated with sleep disorders in the health-sector shift workers.展开更多
Aiming at decreasing the hub transportation costs, a railway hub shift working plan in terms of multicommodity network flow model is set up for considering ...Aiming at decreasing the hub transportation costs, a railway hub shift working plan in terms of multicommodity network flow model is set up for considering the coordination of freight working,train working and locomotive working plans.The solution and the calculating results are also introduced.展开更多
Purpose: To investigate the relationship between stress, fatigue and sleep quality among shift work nurses in Japan. Design: A descriptive correlation design using self-administered surveys. Methods: Questionnaires on...Purpose: To investigate the relationship between stress, fatigue and sleep quality among shift work nurses in Japan. Design: A descriptive correlation design using self-administered surveys. Methods: Questionnaires on stress, fatigue and sleep quality (the Pittsburgh Sleep Quality Index;PSQI-J) among shift work nurses were distributed to 653 nurses in Japan from January 2015 to February 2015. Results: Participants who reported higher levels of fatigue reported higher levels of stress (r = 0.774, p = 0.000), lower levels of sleep satisfaction (r = −0.411, p = 0.000) and overall lower levels of health (r = −0.323, p = 0.000).PSQI scores were also significantly correlated with reported levels of stress (r = 0.294, p = 0.000), fatigue (r = 0.291, p = 0.000) and levels of health (r = −0.370, p = 0.000). Nurses who have stress-relieving recourses were younger (t = −2.842, p = 0.005), reported higher levels of overall health (t = 2.727, p = 0.007), had higher levels of sleep quality measured by the PSQI (t = −2.560, p = 0.011), and required less time to fall asleep (t = −3.207, p = 0.001). Conclusions: This study showed an association between stress and sleep satisfaction among shift work nurses in Japan. In addition, nurses that engage in activities to manage stress might achieve higher levels of health and high sleep quality.展开更多
Introduction: Sleep is critical to human physiological function, cognitive performance, and emotional regulation. Healthcare personnel, especially physicians, are chronically exposed to long working hours, which are o...Introduction: Sleep is critical to human physiological function, cognitive performance, and emotional regulation. Healthcare personnel, especially physicians, are chronically exposed to long working hours, which are often accompanied by decreased sleep time. Clinical evidence indicates that these conditions affect their cognitive function and professional practice, but researchers in the field have not sufficiently explored the possible effects of reductions in sleep time on social cognition. Objective: The aim of this is to further explore the effects of sleep restriction among medical residents, the specific impairments in social cognition that it produces, and the effects of a sleep hygiene orientation on those impairments. Method: There were 124 medical residents (50 males, 74 females) who completed a daily sleep/work log, a battery of sleep tests/questionnaires, and neuropsychological evaluations. The participants then received a short course (8 hours) on basic concepts of sleep hygiene and sleep psychoeducation. Once the course was completed, participants filled out the questionnaires again. Results: The results indicate that sleep disturbances in medical residents were associated with severe neurocognitive and social cognition impairments. After the sleep hygiene intervention, neuropsychological function and sleep parameters improved, awareness increased, and social cognition performance significantly improved. Conclusion: Using sleep psychoeducation and sleep hygiene intervention in medical residents is a simple strategy to mitigate the effects of sleep restriction.展开更多
<strong>Introduction: </strong>The consequences of shift work on health, psychological balance and socio-family life are multiple and universally known. <strong>Objective:</strong> The aim of t...<strong>Introduction: </strong>The consequences of shift work on health, psychological balance and socio-family life are multiple and universally known. <strong>Objective:</strong> The aim of this survey was to describe the impact of shift work on nurses’ health and quality life. <strong>Methodology:</strong> This was a cross-sectional descriptive study of the exposed and non-exposed type from May 2013 to July 2013, <em>i.e.</em> for a period of 3 months. We had included and divided into two groups the nurses working in the various departments of the Loandjili General Hospital (LGH). A questionnaire derived from the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale had been used to collect the data. <strong>Results:</strong> Of the 91 nurses considered, including 59 in shift work (group I) and 32 in daytime work (group II), significant associations were found between shift work on the one hand and sleep problems on the other hand in all these aspects, stress and appetite disturbances. However, no significant association was found between shift work on the one hand and the use of sleeping pills on the other hand. Fatigue, mood disorders and the notion of free time (at home and for leisure), although the frequencies are relatively high in the group of nurses on shift work. <strong>Conclusion:</strong> Our results show that nurses’ health, social and family life at Loandjili General Hospital are negatively impacted by shift work. There is a need to put in place means of prevention.展开更多
Objective:To examine the association between sleep characteristics and night shift work and the risk of polycystic ovary syndrome(PCOS)in Chinese women and to investigate their relationship with infertility in PCOS.Me...Objective:To examine the association between sleep characteristics and night shift work and the risk of polycystic ovary syndrome(PCOS)in Chinese women and to investigate their relationship with infertility in PCOS.Methods:From March 21,2021 to April 31,2021,3927 Chinese women with or without PCOS were recruited online.All participants completed WeChat-based electronic questionnaires.Sleep characteristics were measured using the Pittsburgh sleep quality index.Results:A total of 2871 women were included in the final analysis.Sleep duration(odds ratio[OR],0.857;95%confidence interval[CI],0.763-0.963),sleep midpoint(OR,1.142;95%CI,1.049-1.244),sleep disturbance(OR,1.320;95%CI,0.957-1.146),daytime dysfunction(OR,1.136;95%CI,1.030-1.253),and night shift work(OR,1.628;95%CI,1.264-2.097)were associated with a higher risk of PCOS.After adjusting for confounders,including age,body mass index,smoking status,and coffee and tea drinking status,sleep disturbance(OR,1.314;95%CI,1.111-1.555),daytime dysfunction(OR,1.143;95%CI,1.034-1.264),and night shift work(OR,1.800;95%CI,1.388-2.333)remained associated.In addition,sleep disturbance(OR,1.887;95%CI,1.400-2.542)and subjective sleep quality(OR,1.299;95%CI,1.037-1.627)were associated with infertility in women with PCOS,and sleep disturbance(OR,1.750;95%CI,1.281-2.390)remained significant after adjusting for confounders.Conclusions:Sleep disturbance,daytime dysfunction,and night shift work are significantly associated with PCOS.Screening for sleep disturbances and providing appropriate treatment could be potential strategies for managing PCOS and its long-term complications.展开更多
An optimization solution to roll shifting strategy for alternately rolling campaign is presented. All the strips in a rolling campaign are divided into narrow strips and wide ones, and shifting position of narrow stri...An optimization solution to roll shifting strategy for alternately rolling campaign is presented. All the strips in a rolling campaign are divided into narrow strips and wide ones, and shifting position of narrow strips is obtained by the recursive method, and then shifting position of wide strips is optimized by NSGA-II which is a multiobjective genetic algorithm. For wide strips, a multi-objective optimization model of roll shifting strategy is pro posed, which takes 3 wear contour factors including edge smoothness, body smoothness and edge drop as optimization objectives. The Pareto optimal front of roll shifting strategy can be gained quickly by NSGA-II, which suggests a series of alternative solutions to roll shifting strategy. Analysis shows that the conflict exists among the 3 objectives. The final optimal solution is selected from the Pareto optimal solutions by the weighted-sum decision-making method. Industrial production proves the validity of the solution, and it can improve strip profile of alternately rolling, reduce strip edge wave, and extend the rolling miles of rolling campaigns.展开更多
Considering the effect of work roll shifting on roll temperature field,a finite difference method of PR format for roll temperature field was presented,which can meet the requirements of accuracy and speed of online c...Considering the effect of work roll shifting on roll temperature field,a finite difference method of PR format for roll temperature field was presented,which can meet the requirements of accuracy and speed of online calculation.The step-by-step accumulation method was used to simulate the roll temperature field and thermal crown,and the evolution of roll thermal crown in a rolling campaign was studied.And then,the effects of strip width,rolling rhythm and work roll shifting on roll thermal crown were analyzed.It is found that work roll shifting can disperse the thermal expansion of the roll body especially the edge to make roll thermal contour uniform.The effect of work roll shifting on roll thermal crown is mainly concentrated in regions around twice of roll shifting stroke,and the change range of roll thermal crown is±30μm or so in the same roll body location.展开更多
Many construction projects are met with stringent timelines or the threat of exorbitant liquidated damages. In addition, construction schedulers are frequently forced to incorporate aggressive schedule compression tec...Many construction projects are met with stringent timelines or the threat of exorbitant liquidated damages. In addition, construction schedulers are frequently forced to incorporate aggressive schedule compression techniques. As already discussed by previous researchers, these schedule compression techniques have direct impacts on project productivity and quality defects.Researchers have also pointed out that schedule compression will affect safety incidents such as Occupational Safety & Health Administration recordable injuries and near misses over long project durations. However, most of the existing studies treated safety as a subcategory of project productivity and project quality, and minimal research has been done to directly quantify the effect of schedule compression on safety at the project level.Therefore, in this research, we conducted a survey and statistical analysis to investigate the relationship between schedule compression and safety in construction projects.We interviewed various members of the Houston construction community from both industrial and non-industrial roles. Statistical analysis was used to identify factors that have significant impacts on the occurrence of safety incidents at an industry specific level.展开更多
It is important to find a way to modulate the work function of TiN metal gate towards the valence band edge of Si,which can meet the lower threshold voltage requirement of p-type metal-oxide-semiconductor(MOS) trans...It is important to find a way to modulate the work function of TiN metal gate towards the valence band edge of Si,which can meet the lower threshold voltage requirement of p-type metal-oxide-semiconductor(MOS) transistor.In this work,effects of TiN thickness,post-deposition annealing(PDA),oxygen incorporation and N concentration variation on the work function of TiN metal gate in MOS structures are systematically investigated. It can be found that the work function positively shifts at the initial stage as the thickness of the TiN layer increases and stabilizes at such a thickness.PDA at N_2 ambience with a trace of O_2 can also cause a positive shift in the work function of TiN metal gate.The same tendency can be observed when oxygen is incorporated into TiN.Finally, increasing the N concentration in TiN can also positively shift the work function.All these measures are effective in modulating the TiN metal gate so that it is more suitable for PMOS application.展开更多
文摘This review delved into the intricate relationship between circadian clocks and physiological processes,emphasizing their critical role in maintaining homeo-stasis.Orchestrated by interlocked clock genes,the circadian timekeeping system regulates fundamental processes like the sleep-wake cycle,energy metabolism,immune function,and cell proliferation.The central oscillator in the hypothalamic suprachiasmatic nucleus synchronizes with light-dark cycles,while peripheral tissue clocks are influenced by cues such as feeding times.Circadian disruption,linked to modern lifestyle factors like night shift work,correlates with adverse health outcomes,including metabolic syndrome,cardiovascular diseases,infec-tions,and cancer.We explored the molecular mechanisms of circadian clock genes and their impact on metabolic disorders and cancer pathogenesis.Specific associ-ations between circadian disruption and endocrine tumors,spanning breast,ovarian,testicular,prostate,thyroid,pituitary,and adrenal gland cancers,are highlighted.Shift work is associated with increased breast cancer risk,with PER genes influencing tumor progression and drug resistance.CLOCK gene expression correlates with cisplatin resistance in ovarian cancer,while factors like aging and intermittent fasting affect prostate cancer.Our review underscored the intricate interplay between circadian rhythms and cancer,involving the regulation of the cell cycle,DNA repair,metabolism,immune function,and the tumor microenvir-onment.We advocated for integrating biological timing into clinical consider-ations for personalized healthcare,proposing that understanding these connec-tions could lead to novel therapeutic approaches.Evidence supports circadian rhythm-focused therapies,particularly chronotherapy,for treating endocrine tumors.Our review called for further research to uncover detailed connections between circadian clocks and cancer,providing essential insights for targeted treatments.We emphasized the importance of public health interventions to mitigate lifestyle-related circadian disruptions and underscored the critical role of circadian rhythms in disease mechanisms and therapeutic interventions.
文摘Objective:The aim of the study was to evaluate the quality of sleep in nurses performing shift work in therapeutic and surgical depar tments and to establish possible relationships between level of blood pressure(BP)and quality of sleep.Methods:A total of 20 nurses of the therapeutic depar tments and 20 nurses of the surgical depar tments were enrolled in the study.Sleep quality was assessed using the Pittsburgh Sleep Quality Index(PSQI).BP was measured according to the standard protocol using the Korotkoff method;a sphygmomanometer was used for this twice with an interval of 2 min between 10:00 a.m.and 10:30 a.m.The average value for the 2 indicators was calculated.The diagnosis of essential ar terial hyper tension(AH)was established according to the recommendations of the European Association of Cardiology and the European Association of Hypertension(2018).Results:The overall assessment of the sleep quality of the nurses involved in shift work indicates poor sleep quality;this was true in respondents of both the surgical and therapeutic profiles.However,it was observed that the quality of sleep was significantly lower in nurses of the therapeutic departments.Moreover,poor sleep quality was associated with AH,which was diagnosed in 65%of the nurses of the therapeutic departments and 45%of the nurses of the surgical departments,that is,in almost all of the subjects.Herewith,in the nurses of the therapeutic departments,the level of systolic BP exceeded that of the nurses of the surgical departments.Conclusions:Poor sleep quality is a significant risk factor for AH development and is relevant to nurses performing shift work.Additional clinical studies should be conducted to better understand the mechanisms underlying such adverse cardiometabolic outcomes associated with sleep disorders in the health-sector shift workers.
文摘Aiming at decreasing the hub transportation costs, a railway hub shift working plan in terms of multicommodity network flow model is set up for considering the coordination of freight working,train working and locomotive working plans.The solution and the calculating results are also introduced.
文摘Purpose: To investigate the relationship between stress, fatigue and sleep quality among shift work nurses in Japan. Design: A descriptive correlation design using self-administered surveys. Methods: Questionnaires on stress, fatigue and sleep quality (the Pittsburgh Sleep Quality Index;PSQI-J) among shift work nurses were distributed to 653 nurses in Japan from January 2015 to February 2015. Results: Participants who reported higher levels of fatigue reported higher levels of stress (r = 0.774, p = 0.000), lower levels of sleep satisfaction (r = −0.411, p = 0.000) and overall lower levels of health (r = −0.323, p = 0.000).PSQI scores were also significantly correlated with reported levels of stress (r = 0.294, p = 0.000), fatigue (r = 0.291, p = 0.000) and levels of health (r = −0.370, p = 0.000). Nurses who have stress-relieving recourses were younger (t = −2.842, p = 0.005), reported higher levels of overall health (t = 2.727, p = 0.007), had higher levels of sleep quality measured by the PSQI (t = −2.560, p = 0.011), and required less time to fall asleep (t = −3.207, p = 0.001). Conclusions: This study showed an association between stress and sleep satisfaction among shift work nurses in Japan. In addition, nurses that engage in activities to manage stress might achieve higher levels of health and high sleep quality.
文摘Introduction: Sleep is critical to human physiological function, cognitive performance, and emotional regulation. Healthcare personnel, especially physicians, are chronically exposed to long working hours, which are often accompanied by decreased sleep time. Clinical evidence indicates that these conditions affect their cognitive function and professional practice, but researchers in the field have not sufficiently explored the possible effects of reductions in sleep time on social cognition. Objective: The aim of this is to further explore the effects of sleep restriction among medical residents, the specific impairments in social cognition that it produces, and the effects of a sleep hygiene orientation on those impairments. Method: There were 124 medical residents (50 males, 74 females) who completed a daily sleep/work log, a battery of sleep tests/questionnaires, and neuropsychological evaluations. The participants then received a short course (8 hours) on basic concepts of sleep hygiene and sleep psychoeducation. Once the course was completed, participants filled out the questionnaires again. Results: The results indicate that sleep disturbances in medical residents were associated with severe neurocognitive and social cognition impairments. After the sleep hygiene intervention, neuropsychological function and sleep parameters improved, awareness increased, and social cognition performance significantly improved. Conclusion: Using sleep psychoeducation and sleep hygiene intervention in medical residents is a simple strategy to mitigate the effects of sleep restriction.
文摘<strong>Introduction: </strong>The consequences of shift work on health, psychological balance and socio-family life are multiple and universally known. <strong>Objective:</strong> The aim of this survey was to describe the impact of shift work on nurses’ health and quality life. <strong>Methodology:</strong> This was a cross-sectional descriptive study of the exposed and non-exposed type from May 2013 to July 2013, <em>i.e.</em> for a period of 3 months. We had included and divided into two groups the nurses working in the various departments of the Loandjili General Hospital (LGH). A questionnaire derived from the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale had been used to collect the data. <strong>Results:</strong> Of the 91 nurses considered, including 59 in shift work (group I) and 32 in daytime work (group II), significant associations were found between shift work on the one hand and sleep problems on the other hand in all these aspects, stress and appetite disturbances. However, no significant association was found between shift work on the one hand and the use of sleeping pills on the other hand. Fatigue, mood disorders and the notion of free time (at home and for leisure), although the frequencies are relatively high in the group of nurses on shift work. <strong>Conclusion:</strong> Our results show that nurses’ health, social and family life at Loandjili General Hospital are negatively impacted by shift work. There is a need to put in place means of prevention.
文摘Objective:To examine the association between sleep characteristics and night shift work and the risk of polycystic ovary syndrome(PCOS)in Chinese women and to investigate their relationship with infertility in PCOS.Methods:From March 21,2021 to April 31,2021,3927 Chinese women with or without PCOS were recruited online.All participants completed WeChat-based electronic questionnaires.Sleep characteristics were measured using the Pittsburgh sleep quality index.Results:A total of 2871 women were included in the final analysis.Sleep duration(odds ratio[OR],0.857;95%confidence interval[CI],0.763-0.963),sleep midpoint(OR,1.142;95%CI,1.049-1.244),sleep disturbance(OR,1.320;95%CI,0.957-1.146),daytime dysfunction(OR,1.136;95%CI,1.030-1.253),and night shift work(OR,1.628;95%CI,1.264-2.097)were associated with a higher risk of PCOS.After adjusting for confounders,including age,body mass index,smoking status,and coffee and tea drinking status,sleep disturbance(OR,1.314;95%CI,1.111-1.555),daytime dysfunction(OR,1.143;95%CI,1.034-1.264),and night shift work(OR,1.800;95%CI,1.388-2.333)remained associated.In addition,sleep disturbance(OR,1.887;95%CI,1.400-2.542)and subjective sleep quality(OR,1.299;95%CI,1.037-1.627)were associated with infertility in women with PCOS,and sleep disturbance(OR,1.750;95%CI,1.281-2.390)remained significant after adjusting for confounders.Conclusions:Sleep disturbance,daytime dysfunction,and night shift work are significantly associated with PCOS.Screening for sleep disturbances and providing appropriate treatment could be potential strategies for managing PCOS and its long-term complications.
基金Item Sponsored by National Natural Science Foundation of China(50974039)
文摘An optimization solution to roll shifting strategy for alternately rolling campaign is presented. All the strips in a rolling campaign are divided into narrow strips and wide ones, and shifting position of narrow strips is obtained by the recursive method, and then shifting position of wide strips is optimized by NSGA-II which is a multiobjective genetic algorithm. For wide strips, a multi-objective optimization model of roll shifting strategy is pro posed, which takes 3 wear contour factors including edge smoothness, body smoothness and edge drop as optimization objectives. The Pareto optimal front of roll shifting strategy can be gained quickly by NSGA-II, which suggests a series of alternative solutions to roll shifting strategy. Analysis shows that the conflict exists among the 3 objectives. The final optimal solution is selected from the Pareto optimal solutions by the weighted-sum decision-making method. Industrial production proves the validity of the solution, and it can improve strip profile of alternately rolling, reduce strip edge wave, and extend the rolling miles of rolling campaigns.
基金Sponsored by National Natural Science Foundation of China(51205336)Fujian Natural Science Foundation of China(2013J05086)
文摘Considering the effect of work roll shifting on roll temperature field,a finite difference method of PR format for roll temperature field was presented,which can meet the requirements of accuracy and speed of online calculation.The step-by-step accumulation method was used to simulate the roll temperature field and thermal crown,and the evolution of roll thermal crown in a rolling campaign was studied.And then,the effects of strip width,rolling rhythm and work roll shifting on roll thermal crown were analyzed.It is found that work roll shifting can disperse the thermal expansion of the roll body especially the edge to make roll thermal contour uniform.The effect of work roll shifting on roll thermal crown is mainly concentrated in regions around twice of roll shifting stroke,and the change range of roll thermal crown is±30μm or so in the same roll body location.
文摘Many construction projects are met with stringent timelines or the threat of exorbitant liquidated damages. In addition, construction schedulers are frequently forced to incorporate aggressive schedule compression techniques. As already discussed by previous researchers, these schedule compression techniques have direct impacts on project productivity and quality defects.Researchers have also pointed out that schedule compression will affect safety incidents such as Occupational Safety & Health Administration recordable injuries and near misses over long project durations. However, most of the existing studies treated safety as a subcategory of project productivity and project quality, and minimal research has been done to directly quantify the effect of schedule compression on safety at the project level.Therefore, in this research, we conducted a survey and statistical analysis to investigate the relationship between schedule compression and safety in construction projects.We interviewed various members of the Houston construction community from both industrial and non-industrial roles. Statistical analysis was used to identify factors that have significant impacts on the occurrence of safety incidents at an industry specific level.
基金supported by the Important National Science & Technology Specific Projects,China(No.2009ZX02035)the National Natural Science Foundation of China(Nos.61176091,50932001)
文摘It is important to find a way to modulate the work function of TiN metal gate towards the valence band edge of Si,which can meet the lower threshold voltage requirement of p-type metal-oxide-semiconductor(MOS) transistor.In this work,effects of TiN thickness,post-deposition annealing(PDA),oxygen incorporation and N concentration variation on the work function of TiN metal gate in MOS structures are systematically investigated. It can be found that the work function positively shifts at the initial stage as the thickness of the TiN layer increases and stabilizes at such a thickness.PDA at N_2 ambience with a trace of O_2 can also cause a positive shift in the work function of TiN metal gate.The same tendency can be observed when oxygen is incorporated into TiN.Finally, increasing the N concentration in TiN can also positively shift the work function.All these measures are effective in modulating the TiN metal gate so that it is more suitable for PMOS application.