Objective To investigate the co-effect of Demand-control-support （DCS） model and Effort-reward Imbalance （ERI） model on the risk estimation of depression in humans in comparison with the effects when they are used...Objective To investigate the co-effect of Demand-control-support （DCS） model and Effort-reward Imbalance （ERI） model on the risk estimation of depression in humans in comparison with the effects when they are used respectively. Methods A total of 3 632 males and 1 706 females from 13 factories and companies in Henan province were recruited in this cross-sectional study. Perceived job stress was evaluated with the Job Content Questionnaire and Effort-Reward Imbalance Questionnaire （Chinese version）. Depressive symptoms were assessed by using the Center for Epidemiological Studies Depression Scale （CES-D）. Results DC （demands/job control ratio） and ERI were shown to be independently associated with depressive symptoms. The outcome of low social support and overcommitment were similar. High DC and low social support （SS）, high ERI and high overcommitment, and high DC and high ERI posed greater risks of depressive symptoms than each of them did alone. ERI model and SS model seem to be effective in estimating the risk of depressive symptoms if they are used respectively. Conclusion The DC had better performance when it was used in combination with low SS. The effect on physical demands was better than on psychological demands. The combination of DCS and ERI models could improve the risk estimate of depressive symptoms in humans.展开更多
针对新能源大量接入背景下电力系统频率调节能力紧张、旋转备用不足的问题,提出一种“源网荷”协同的二次调频策略。通过柔性直流输电(voltage source converter-high voltage direct current,VSC-HVDC)系统将拥有丰富可控资源的电解铝...针对新能源大量接入背景下电力系统频率调节能力紧张、旋转备用不足的问题,提出一种“源网荷”协同的二次调频策略。通过柔性直流输电(voltage source converter-high voltage direct current,VSC-HVDC)系统将拥有丰富可控资源的电解铝工业电网与传统电力系统互联,建立考虑VSC-HVDC功率支援的两端互联系统二次调频模型。基于互联系统频率控制模型构建分布式架构,在两端设计模型预测控制器,控制器在本区域内进行优化控制,定期进行信息交互,主动调节电解铝负荷功耗进行需求响应,减轻由功率支援引起的送端系统功率不平衡。最后以我国西部地区某工业电网的实际数据进行仿真验证了所提出策略的有效性。结果表明,在大扰动场景下,所提出的策略可以将受端系统频率恢复时间缩短约30%,同时在调控过程中,送端系统频率偏差始终保持在0.05 Hz以内,且电解铝负荷与VSC-HVDC系统参数始终处于安全范围内。展开更多
基金funded by Henan Provincial Health Science and Technology Key Projects(201001009)National Science and Technology Infrastructure Program(2006BAI06B 08),China
文摘Objective To investigate the co-effect of Demand-control-support （DCS） model and Effort-reward Imbalance （ERI） model on the risk estimation of depression in humans in comparison with the effects when they are used respectively. Methods A total of 3 632 males and 1 706 females from 13 factories and companies in Henan province were recruited in this cross-sectional study. Perceived job stress was evaluated with the Job Content Questionnaire and Effort-Reward Imbalance Questionnaire （Chinese version）. Depressive symptoms were assessed by using the Center for Epidemiological Studies Depression Scale （CES-D）. Results DC （demands/job control ratio） and ERI were shown to be independently associated with depressive symptoms. The outcome of low social support and overcommitment were similar. High DC and low social support （SS）, high ERI and high overcommitment, and high DC and high ERI posed greater risks of depressive symptoms than each of them did alone. ERI model and SS model seem to be effective in estimating the risk of depressive symptoms if they are used respectively. Conclusion The DC had better performance when it was used in combination with low SS. The effect on physical demands was better than on psychological demands. The combination of DCS and ERI models could improve the risk estimate of depressive symptoms in humans.
文摘针对新能源大量接入背景下电力系统频率调节能力紧张、旋转备用不足的问题,提出一种“源网荷”协同的二次调频策略。通过柔性直流输电(voltage source converter-high voltage direct current,VSC-HVDC)系统将拥有丰富可控资源的电解铝工业电网与传统电力系统互联,建立考虑VSC-HVDC功率支援的两端互联系统二次调频模型。基于互联系统频率控制模型构建分布式架构,在两端设计模型预测控制器,控制器在本区域内进行优化控制,定期进行信息交互,主动调节电解铝负荷功耗进行需求响应,减轻由功率支援引起的送端系统功率不平衡。最后以我国西部地区某工业电网的实际数据进行仿真验证了所提出策略的有效性。结果表明,在大扰动场景下,所提出的策略可以将受端系统频率恢复时间缩短约30%,同时在调控过程中,送端系统频率偏差始终保持在0.05 Hz以内,且电解铝负荷与VSC-HVDC系统参数始终处于安全范围内。
