This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/...This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/2 000 kVA) for the quay cranes is used for the power input of the system, after frequency and voltage converting (450 V/60 Hz), then putting out and supplying to vessel. This system is flexible with positive effect on energy-saving and emission reduction; besides, there's no requirement of civil reconstruction to container terminals, which is suitable for the busy ports in China.展开更多
目的观察钾通道开放剂尼可地尔对冠心病Warm-up现象及患者反复运动后心率恢复(HRR)的影响。方法选择运动试验阳性以及经冠脉造影证实至少单支冠脉狭窄程度在70%~90%的慢性稳定型心绞痛患者75例。根据干预药物不同分为对照组(常规治...目的观察钾通道开放剂尼可地尔对冠心病Warm-up现象及患者反复运动后心率恢复(HRR)的影响。方法选择运动试验阳性以及经冠脉造影证实至少单支冠脉狭窄程度在70%~90%的慢性稳定型心绞痛患者75例。根据干预药物不同分为对照组(常规治疗)、尼可地尔组(常规治疗+尼可地尔口服5 mg,3次/d)及单硝酸异山梨酯组(常规治疗+单硝酸异山梨酯口服20 mg,2次/d),各25例。各组均服药6个月以上。通过间隔15 min的连续两次运动试验(EX1与EX2)来观察各组缺血阈值(ST段压低0.1 m V时心率血压乘积即RPP值)、出现ST段压低0.1 m V时间(T-STD)、ST段压低的最大值(STDmax)、ST段恢复压低0.05 m V时间、总运动时间(ED)等反映心电图缺血情况的指标以及HRR的变化。结果 3组前后两次运动相比,EX2各指标均较EX1有明显改善(P均〈0.05);单硝酸异山梨酯组仅STDmax高于对照组(P〈0.05);尼可地尔组在RPP、T-STD、ST段恢复压低0.05m V时间、STDmax方面均明显优于对照组(P均〈0.01)和单硝酸异山梨酯组(P〈0.05或〈0.01);尼可地尔组EX1后与EX2后HRR比较,P〈0.01,与对照组比较,P〈0.05。结论尼可地尔可促进冠心病Warm-up现象的发生,钾通道可能作为重要机制参与其中;同时尼可地尔有利于HRR。展开更多
目的观察尼可地尔对冠心病心绞痛患者发生Warm-up现象的影响。方法选择运动试验阳性和经冠脉造影证实至少单支冠脉狭窄程度为70%~90%的慢性稳定型心绞痛患者作为研究对象,共50例入选。根据干预药物不同分为对照组(常规治疗)和治疗组...目的观察尼可地尔对冠心病心绞痛患者发生Warm-up现象的影响。方法选择运动试验阳性和经冠脉造影证实至少单支冠脉狭窄程度为70%~90%的慢性稳定型心绞痛患者作为研究对象,共50例入选。根据干预药物不同分为对照组(常规治疗)和治疗组(常规治疗+尼可地尔),每组25例。分别进行间隔15 min连续2次踏车运动实验(EX1,EX2),观察运动时间(ED,s)、出现ST段压低0.1 m V时间(T-STD,s)、ST段压低的最大值(STDmax,mm)以及缺血阈值(ST段压低0.1 m V时心率血压乘积即RPP值,beats·min-1·mm Hg·102)等指标的组内及组间变化。结果 2组患者分别于前后2次运动(EX1与EX2)比较,EX2各指标较EX1均有明显改善(P〈0.05);且治疗组在缺血阈值、T-STD、STDmax方面改善度均明显优于对照组(P〈0.01)。结论尼可地尔可有效促进冠心病Warm-up现象的发生,进而增强缺血心肌的自我保护作用。展开更多
目的观察warm-up现象对缺血心脏的保护及硝酸酯类药物对warm-up现象的影响。方法选择运动试验阳性和经冠脉造影证实至少单支冠脉狭窄程度为70%~90%的慢性稳定型心绞痛患者作为研究对象,共50例患者入选。根据干预药物不同分为对照组(常...目的观察warm-up现象对缺血心脏的保护及硝酸酯类药物对warm-up现象的影响。方法选择运动试验阳性和经冠脉造影证实至少单支冠脉狭窄程度为70%~90%的慢性稳定型心绞痛患者作为研究对象,共50例患者入选。根据干预药物不同分为对照组(常规治疗)和治疗组(常规治疗+单硝酸异山梨酯),每组25例。分别进行间隔15 min的连续两次踏车运动实验(EX1,EX2),观察运动时间(ED)、出现ST段压低0.1 m V时间(T-STD)、ST段压低的最大值(STDmax)以及ST段压低0.1 m V时的心率收缩压乘积(RPP)等指标的组内及组间变化。结果 2组患者前后两次运动(EX1与EX2)相比,EX2各指标较EX1均有明显改善(P〈0.05);而治疗组仅在STDmax方面改善优于对照组(P〈0.05)。结论运动可以诱发慢性稳定型心绞痛患者发生warm-up现象保护缺血心肌,冠脉舒张可能并未作为重要机制参与其中。展开更多
Well begun is half done。良好的Warm-up是上好一堂课的基石,也是激发学生学习兴趣的关键环节。苏霍姆林斯基曾经说过:"如果教师不想办法使学生产生情绪高昂和智力振奋的内心状态,就急于传授知识,那么这种知识只能使人产生冷漠的...Well begun is half done。良好的Warm-up是上好一堂课的基石,也是激发学生学习兴趣的关键环节。苏霍姆林斯基曾经说过:"如果教师不想办法使学生产生情绪高昂和智力振奋的内心状态,就急于传授知识,那么这种知识只能使人产生冷漠的态度,而使不动感情的脑力劳动带来疲劳。"别具匠心、引人入胜的Warm-up,能及时地吸引学生的注意力,激发学生的学习热情。展开更多
Background:Football is the most practised sport in the world and is associated with the risk of injuries in the players.Some studies have been published that identify injury prevention programs,but there is no review ...Background:Football is the most practised sport in the world and is associated with the risk of injuries in the players.Some studies have been published that identify injury prevention programs,but there is no review of the full body of evidence on injury prevention programs for use by football coaches.The aim of this article was to carry out a systematic review of published studies on injury prevention programs for adult male footballers,identify points of common understanding and establish recommendations that should be considered in the design of injury prevention strategies.Methods:PubMed and EMBASE databases were used to identify relevant published articles using the following keywords:"soccer"AND"injury"AND"prevention".Results:A total of 2512 studies were identified initially,but only 11 studies met the inclusion criteria,and their outcomes are presented.Results revealed that injury prevention programs in football have focused on strength training,proprioceptive training,multicomponent programs(balance,core stability,and functional strength and mobility),and warm-up programs.Conclusion:Based on results from the studies analyzed,football players can lower the incidence of match and training injuries by participating in dynamic warm-up programs that include preventive exercises before games or during training sessions,and by adding strength,balance,and mobility training to the training sessions.展开更多
Gasoline compression ignition (GCI) is one of the most promising combustion concepts to maintain low pollutant emissions and high efficiency. However, low load combustion stability and firing in cold-start operations ...Gasoline compression ignition (GCI) is one of the most promising combustion concepts to maintain low pollutant emissions and high efficiency. However, low load combustion stability and firing in cold-start operations are two major challenges for GCI combustion. Strategies including negative valve overlap (NVO), advanced injection strategies, fuel reforming, and intake preheating have been proposed in order to solve these difficulties;however, the cold start is still an obstacle. The objective of this work is to study effective methods to achieve GCI engine cold start-up. This work combines NVO, in-cylinder fuel reforming, and intake preheating to achieve quick firing under cold-start conditions and the subsequent warmup conditions. The results show that start of injection (SOI) during the intake stroke yields the best fuel economy, and injection during the compression stroke has the potential to extend the low load limit. Furthermore, SOI during the NVO period grants the ability to operate under engine conditions with cold intake air and coolant. With highly reactive products made by in-cylinder fuel reforming and fast heat accumulation in the combustion chamber, the NVO injection strategy is highly appropriate for GCI firing. An additional assisted technical method, such as intake preheating, is required to ignite the first firing cycle for a cold-start process. With the combination of NVO, in-cylinder fuel reforming, and intake preheating, the GCI engine successfully started within five combustion cycles in the experiment. After the firing process, the engine could stably operate without further intake preheating;thus, this method is appropriate for engine cold-start and warm-up.展开更多
Background:Traditional vertical and side-alternating whole body vibrations(WBV) can effectively improve muscle power performance but have a limited efficacy for enhancing change-of-direction(COD) ability.Novel dual-pl...Background:Traditional vertical and side-alternating whole body vibrations(WBV) can effectively improve muscle power performance but have a limited efficacy for enhancing change-of-direction(COD) ability.Novel dual-plate WBV uniquely providing various directions of movements with higher and distinctive frequencies for each leg may cause better acute effect on muscle power and stretch-shortening cycle efficacy contributing to COD ability.Therefore,the purpose of this study was to investigate the acute effect of dual-or single-frequency WBV on squat jumps(SJs),countermovement jumps(CMJs),eccentric utilization ratios(EURs),and COD ability in rugby players.Methods:Fourteen male rugby players were recruited and performed a 4 min partial squat with 3 types of WBV protocols on a dual-plate WBV machine,including 1 dual-frequency WBV protocol(DFW) with the dominant leg receiving 35 Hz and the non-dominant leg receiving 45 Hz,and2 single-frequency WBV protocols(SFWs) with 35 Hz or 45 Hz provided to both legs(SFW35Hz and SFW45Hz) on 3 different days.Results:The results showed that all the vibration protocols significantly improved SJ and CMJ performances(SJ:p = 0.008;CMJ:p < 0.001),but did not significantly change EURs(p > 0.05).In addition,only the DFW significantly improved COD ability(p = 0.001 for the pre–post comparison).Conclusion:A 4 min dual-frequency WBV session improved both vertical jumping and COD ability in rugby players,suggesting that this could be a potential warm-up protocol for athletes.展开更多
Public enthusiasm marks the Sixth Asian Winter Games China’s motor-city Changchun, Jilin Province, came into the spotlight fora reasonother than cars this year as host of the Sixth Asian Winter Games.
Serverless computing has become increasingly popular recently due to its cost efficiency and flexibility.However,running serverless computing functions in the cloud can incur high end-to-end service latency and operat...Serverless computing has become increasingly popular recently due to its cost efficiency and flexibility.However,running serverless computing functions in the cloud can incur high end-to-end service latency and operational costs.Running them on edge servers may significantly reduce service latency but is limited by computing power and memory availability.Given the limitations of cloud and edge environments for performing serverless com-puting,this paper proposes a joint function warm-up and request routing scheme to perform serverless computing functions on edge and cloud collaboratively.The key idea of the new scheme is to maximize the hit ratio of server-less computing requests,thereby reducing the cold-start latency that dominates the overall serving latency.This scheme explicitly considers allocating server memory and operation budget for executing concurrent requests during the scheduling.The proposed scheme has been evaluated through extensive simulations.Its effectiveness has been proved by comparison with the upper-bound results.展开更多
文摘This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/2 000 kVA) for the quay cranes is used for the power input of the system, after frequency and voltage converting (450 V/60 Hz), then putting out and supplying to vessel. This system is flexible with positive effect on energy-saving and emission reduction; besides, there's no requirement of civil reconstruction to container terminals, which is suitable for the busy ports in China.
文摘目的观察钾通道开放剂尼可地尔对冠心病Warm-up现象及患者反复运动后心率恢复(HRR)的影响。方法选择运动试验阳性以及经冠脉造影证实至少单支冠脉狭窄程度在70%~90%的慢性稳定型心绞痛患者75例。根据干预药物不同分为对照组(常规治疗)、尼可地尔组(常规治疗+尼可地尔口服5 mg,3次/d)及单硝酸异山梨酯组(常规治疗+单硝酸异山梨酯口服20 mg,2次/d),各25例。各组均服药6个月以上。通过间隔15 min的连续两次运动试验(EX1与EX2)来观察各组缺血阈值(ST段压低0.1 m V时心率血压乘积即RPP值)、出现ST段压低0.1 m V时间(T-STD)、ST段压低的最大值(STDmax)、ST段恢复压低0.05 m V时间、总运动时间(ED)等反映心电图缺血情况的指标以及HRR的变化。结果 3组前后两次运动相比,EX2各指标均较EX1有明显改善(P均〈0.05);单硝酸异山梨酯组仅STDmax高于对照组(P〈0.05);尼可地尔组在RPP、T-STD、ST段恢复压低0.05m V时间、STDmax方面均明显优于对照组(P均〈0.01)和单硝酸异山梨酯组(P〈0.05或〈0.01);尼可地尔组EX1后与EX2后HRR比较,P〈0.01,与对照组比较,P〈0.05。结论尼可地尔可促进冠心病Warm-up现象的发生,钾通道可能作为重要机制参与其中;同时尼可地尔有利于HRR。
文摘目的观察尼可地尔对冠心病心绞痛患者发生Warm-up现象的影响。方法选择运动试验阳性和经冠脉造影证实至少单支冠脉狭窄程度为70%~90%的慢性稳定型心绞痛患者作为研究对象,共50例入选。根据干预药物不同分为对照组(常规治疗)和治疗组(常规治疗+尼可地尔),每组25例。分别进行间隔15 min连续2次踏车运动实验(EX1,EX2),观察运动时间(ED,s)、出现ST段压低0.1 m V时间(T-STD,s)、ST段压低的最大值(STDmax,mm)以及缺血阈值(ST段压低0.1 m V时心率血压乘积即RPP值,beats·min-1·mm Hg·102)等指标的组内及组间变化。结果 2组患者分别于前后2次运动(EX1与EX2)比较,EX2各指标较EX1均有明显改善(P〈0.05);且治疗组在缺血阈值、T-STD、STDmax方面改善度均明显优于对照组(P〈0.01)。结论尼可地尔可有效促进冠心病Warm-up现象的发生,进而增强缺血心肌的自我保护作用。
文摘目的观察warm-up现象对缺血心脏的保护及硝酸酯类药物对warm-up现象的影响。方法选择运动试验阳性和经冠脉造影证实至少单支冠脉狭窄程度为70%~90%的慢性稳定型心绞痛患者作为研究对象,共50例患者入选。根据干预药物不同分为对照组(常规治疗)和治疗组(常规治疗+单硝酸异山梨酯),每组25例。分别进行间隔15 min的连续两次踏车运动实验(EX1,EX2),观察运动时间(ED)、出现ST段压低0.1 m V时间(T-STD)、ST段压低的最大值(STDmax)以及ST段压低0.1 m V时的心率收缩压乘积(RPP)等指标的组内及组间变化。结果 2组患者前后两次运动(EX1与EX2)相比,EX2各指标较EX1均有明显改善(P〈0.05);而治疗组仅在STDmax方面改善优于对照组(P〈0.05)。结论运动可以诱发慢性稳定型心绞痛患者发生warm-up现象保护缺血心肌,冠脉舒张可能并未作为重要机制参与其中。
文摘Well begun is half done。良好的Warm-up是上好一堂课的基石,也是激发学生学习兴趣的关键环节。苏霍姆林斯基曾经说过:"如果教师不想办法使学生产生情绪高昂和智力振奋的内心状态,就急于传授知识,那么这种知识只能使人产生冷漠的态度,而使不动感情的脑力劳动带来疲劳。"别具匠心、引人入胜的Warm-up,能及时地吸引学生的注意力,激发学生的学习热情。
文摘Background:Football is the most practised sport in the world and is associated with the risk of injuries in the players.Some studies have been published that identify injury prevention programs,but there is no review of the full body of evidence on injury prevention programs for use by football coaches.The aim of this article was to carry out a systematic review of published studies on injury prevention programs for adult male footballers,identify points of common understanding and establish recommendations that should be considered in the design of injury prevention strategies.Methods:PubMed and EMBASE databases were used to identify relevant published articles using the following keywords:"soccer"AND"injury"AND"prevention".Results:A total of 2512 studies were identified initially,but only 11 studies met the inclusion criteria,and their outcomes are presented.Results revealed that injury prevention programs in football have focused on strength training,proprioceptive training,multicomponent programs(balance,core stability,and functional strength and mobility),and warm-up programs.Conclusion:Based on results from the studies analyzed,football players can lower the incidence of match and training injuries by participating in dynamic warm-up programs that include preventive exercises before games or during training sessions,and by adding strength,balance,and mobility training to the training sessions.
基金the National Natural Science Foundation of China (91641203, 51476114, and 91741119)he National Key Research and Development Program of China (2017YFB0103400).
文摘Gasoline compression ignition (GCI) is one of the most promising combustion concepts to maintain low pollutant emissions and high efficiency. However, low load combustion stability and firing in cold-start operations are two major challenges for GCI combustion. Strategies including negative valve overlap (NVO), advanced injection strategies, fuel reforming, and intake preheating have been proposed in order to solve these difficulties;however, the cold start is still an obstacle. The objective of this work is to study effective methods to achieve GCI engine cold start-up. This work combines NVO, in-cylinder fuel reforming, and intake preheating to achieve quick firing under cold-start conditions and the subsequent warmup conditions. The results show that start of injection (SOI) during the intake stroke yields the best fuel economy, and injection during the compression stroke has the potential to extend the low load limit. Furthermore, SOI during the NVO period grants the ability to operate under engine conditions with cold intake air and coolant. With highly reactive products made by in-cylinder fuel reforming and fast heat accumulation in the combustion chamber, the NVO injection strategy is highly appropriate for GCI firing. An additional assisted technical method, such as intake preheating, is required to ignite the first firing cycle for a cold-start process. With the combination of NVO, in-cylinder fuel reforming, and intake preheating, the GCI engine successfully started within five combustion cycles in the experiment. After the firing process, the engine could stably operate without further intake preheating;thus, this method is appropriate for engine cold-start and warm-up.
文摘Background:Traditional vertical and side-alternating whole body vibrations(WBV) can effectively improve muscle power performance but have a limited efficacy for enhancing change-of-direction(COD) ability.Novel dual-plate WBV uniquely providing various directions of movements with higher and distinctive frequencies for each leg may cause better acute effect on muscle power and stretch-shortening cycle efficacy contributing to COD ability.Therefore,the purpose of this study was to investigate the acute effect of dual-or single-frequency WBV on squat jumps(SJs),countermovement jumps(CMJs),eccentric utilization ratios(EURs),and COD ability in rugby players.Methods:Fourteen male rugby players were recruited and performed a 4 min partial squat with 3 types of WBV protocols on a dual-plate WBV machine,including 1 dual-frequency WBV protocol(DFW) with the dominant leg receiving 35 Hz and the non-dominant leg receiving 45 Hz,and2 single-frequency WBV protocols(SFWs) with 35 Hz or 45 Hz provided to both legs(SFW35Hz and SFW45Hz) on 3 different days.Results:The results showed that all the vibration protocols significantly improved SJ and CMJ performances(SJ:p = 0.008;CMJ:p < 0.001),but did not significantly change EURs(p > 0.05).In addition,only the DFW significantly improved COD ability(p = 0.001 for the pre–post comparison).Conclusion:A 4 min dual-frequency WBV session improved both vertical jumping and COD ability in rugby players,suggesting that this could be a potential warm-up protocol for athletes.
文摘Public enthusiasm marks the Sixth Asian Winter Games China’s motor-city Changchun, Jilin Province, came into the spotlight fora reasonother than cars this year as host of the Sixth Asian Winter Games.
文摘Serverless computing has become increasingly popular recently due to its cost efficiency and flexibility.However,running serverless computing functions in the cloud can incur high end-to-end service latency and operational costs.Running them on edge servers may significantly reduce service latency but is limited by computing power and memory availability.Given the limitations of cloud and edge environments for performing serverless com-puting,this paper proposes a joint function warm-up and request routing scheme to perform serverless computing functions on edge and cloud collaboratively.The key idea of the new scheme is to maximize the hit ratio of server-less computing requests,thereby reducing the cold-start latency that dominates the overall serving latency.This scheme explicitly considers allocating server memory and operation budget for executing concurrent requests during the scheduling.The proposed scheme has been evaluated through extensive simulations.Its effectiveness has been proved by comparison with the upper-bound results.