The 20,000-ton combined train running has greatly promoted China’s heavy-haul railway transportation capability. The application of controllable train-tail devices could improve the braking wave of the train and brak...The 20,000-ton combined train running has greatly promoted China’s heavy-haul railway transportation capability. The application of controllable train-tail devices could improve the braking wave of the train and braking synchronism, and alleviate longitudinal impulse.However, the characteristics of the controllable train-tail device such as exhaust area, exhaust duration and exhaust action time are not uniform in practice, and their effects on the longitudinal impulse of the train are not apparent,which is worth studying. In this work, according to the formation of the Datong-Qinhuangdao Railway, the train air brake and longitudinal dynamics simulation system(TABLDSS) is applied to establish a 20,000-ton combined train model with the controllable train-tail device, and the braking characteristics and the longitudinal impulse of the train are calculated synchronously with changing the air exhaust time, exhaust area, and action lag time under initial braking. The results show that the maximum coupler force of the combined train will decrease with the extension of the continuous exhaust time, while the total exhaust time of the controllable train-tail device remains unchanged;the maximum coupler force of the combined train reduces by32.5% with the exhaust area increasing from 70% to 140%;when the lag time between the controllable train-tail device and the master locomotive is more than 1.5 s, the maximum coupler force of the train increases along with the time difference enlargement.展开更多
Objective:Previous studies have shown that exercise suppresses tumor growth.However,the effects of exercise with different intensities and exercise detraining after tumor-bearing on tumor progression remain unclear.Th...Objective:Previous studies have shown that exercise suppresses tumor growth.However,the effects of exercise with different intensities and exercise detraining after tumor-bearing on tumor progression remain unclear.The purpose of this study was to investigate the effects of continuous and disrupted free and exhausted swimming training after tumor-bearing on tumor progression in melanoma B16-F10-bearing C57BL/6 mice.Methods:C57BL/6 mice were subjected to free or exhausted swimming exercise training for 4 weeks prior to the injection of melanoma B16-F10 cells.Subsequently,the B16-F10-bearing mice were maintained with training consisting of free or exhausted swimming or without exercise for 2 weeks during the tumor challenge.Results:The tumor weight was increased by 42%and 109%in mice with 4-week exhausted swimming prior to B16-F10 tumor cells inoculation followed by 2-week training cessation compared with the tumor-bearing control(P<.05)and continuous training groups(P<.01).Tumor weights in groups with exercise detraining after tumor cell inoculation tended to be increased,while the proliferation of splenic T lymphocytes tended to be decreased compared with the group that maintained exercise intensity.After 6-weeks continuous free or exhausted swimming training,the tumor weight of mice was decreased and the proliferation of splenic T lymphocytes was increased compared with the tumor-bearing control group.The frequency of natural killer cells in tumors was increased in all exercise training groups of mice.Conclusions:These results suggest that maintaining exercise intensity after tumor-bearing slows tumor growth in mice,possibly because of the enhanced proliferative activity of splenic lymphocytes rather than natural killer cell infiltration.However,detraining after tumor-bearing might accelerate tumor progression because of the reduced proliferation of splenic T lymphocytes.展开更多
Background:Doctoral students have much higher risk of anxiety or depression than general population.Doctoral students worldwide are facing varying degrees of mental health risks.Method:Based on the survey data of 6,81...Background:Doctoral students have much higher risk of anxiety or depression than general population.Doctoral students worldwide are facing varying degrees of mental health risks.Method:Based on the survey data of 6,812 doctoral students worldwide in Nature in 2019,Probit and Logit models are used to explore the correlation between thefit of doctoral education and training process and the mental health of doctoral students.Results:(1)The training environmentfit of doctoral students has a significant positive impact on their mental health.(2)The academic professionfit of doctoral students has a significant positive impact on their mental health.(3)The orga-nizational culturefit of doctoral students has a significant positive impact on their mental health.(4)Thefinancial supportfit of doctoral students has a significant positive impact on their mental health.Conclusion:The higher the degree of doctoral students’training environmentfit,academic professionfit,organizational culturefit,andfinancial supportfit,the lower the possibility of anxiety or depression among doctoral students.The current research results can help reveal extensive factors that affect the mental health of doctoral students,facilitate the planning and development of effective intervention measures by universities,improve thefit of the doctoral education and training process,improve the mental health of doctoral students,and boost academic excellence.展开更多
Objective:To investigate the effect of high-intensity interval training on blood glucose control, adipocytokine secretion and oxidative stress response in patients with T2DM.Methods: A total of 92 patients with newly ...Objective:To investigate the effect of high-intensity interval training on blood glucose control, adipocytokine secretion and oxidative stress response in patients with T2DM.Methods: A total of 92 patients with newly diagnosed T2DM who were treated in this hospital between July 2016 and July 2017 were divided into the control group (n=46) and HIIT group (n=46) by random number table method. Control group received conventional hypoglycemic therapy, HIIT group received hypoglycemic combined with high-intensity interval training therapy, and the intervention lasted for 3 months. The differences in blood glucose control, adipocytokine secretion and oxidative stress response were compared between the two groups before and after intervention.Results: Before intervention, the differences in blood glucose index levels in peripheral blood as well as the contents of adipocytokines and oxidative stress indexes in serum were not statistically significant between the two groups of patients. After 3 months of intervention, blood glucose indexes FPG, FINS and 2hPBG levels in peripheral blood of HIIT group were lower than those of control group;adipocytokine APN content in serum was higher than that of control group whereas LEP, Resistin and CHEM contents were lower than those of control group;oxidative stress indexes MDA and ROS contents in serum were lower than those of control group whereas T-AOC content was higher than that of control group. Conclusion: Routine hypoglycemic therapy combined with high-intensity interval training can further control the blood glucose levels, regulate the secretion of adipocytokines and reduce the systemic oxidative stress response.展开更多
In shipping,which is one of the drivers of the world’s economy,many marine accidents continue to occur,such as ship collisions and grounding.To reduce marine collision accidents,seafarers’skills must be improved thr...In shipping,which is one of the drivers of the world’s economy,many marine accidents continue to occur,such as ship collisions and grounding.To reduce marine collision accidents,seafarers’skills must be improved through training.Therefore,the authors propose a ship handling training for collision avoidance(hereinafter referred to as“T for CA”)in which a group of several people discusses the ship handling for collision avoidance,assuming the situation of the collision avoidance.After T for CA implementation,anchoring training was done and the effect of T for CA was verified through comparison with a group where T for CA was not applied.Two instructors evaluated the anchoring training conducted with and without“T for CA”.The anchoring training experiment showed a difference of 27.5%in the achievement rate between the proposed training and previous training.T for CA maximises the effects of group work and resulted in good evaluations in the anchoring training experiments.The training was effective because the students themselves set the scenarios and devised ship handling strategies for collision avoidance.In addition,group work discussions helped deepen students’knowledge and skills.展开更多
E-learning platforms support education systems worldwide, transferring theoretical knowledge as well as soft skills. In the present study high-school pupils’, and adult students’ opinions were evaluated through a mo...E-learning platforms support education systems worldwide, transferring theoretical knowledge as well as soft skills. In the present study high-school pupils’, and adult students’ opinions were evaluated through a modern structured MOODLE interactive course, designed for the needs of the laboratory course “Automotive Systems”. The study concerns Greek secondary vocational education pupils aged 18 and vocational training adult students aged 20 to 50 years. The multistage, equal size simple random cluster sample was used as a sampling method. Pupils and adult students of each cluster completed structured 10-question questionnaires both before and after attending the course. A total of 120 questionnaires were collected. In general, our findings disclosed that the majority of pupils and adult students had significantly improved their knowledge and skills from using MOODLE. They reported strengthening conventional teaching, using the new MOODLE technology. The satisfaction indices improved quite, with the differences in their mean values being statistically significant.展开更多
基金China National Railway Group Co.,Ltd(N2020J037).
文摘The 20,000-ton combined train running has greatly promoted China’s heavy-haul railway transportation capability. The application of controllable train-tail devices could improve the braking wave of the train and braking synchronism, and alleviate longitudinal impulse.However, the characteristics of the controllable train-tail device such as exhaust area, exhaust duration and exhaust action time are not uniform in practice, and their effects on the longitudinal impulse of the train are not apparent,which is worth studying. In this work, according to the formation of the Datong-Qinhuangdao Railway, the train air brake and longitudinal dynamics simulation system(TABLDSS) is applied to establish a 20,000-ton combined train model with the controllable train-tail device, and the braking characteristics and the longitudinal impulse of the train are calculated synchronously with changing the air exhaust time, exhaust area, and action lag time under initial braking. The results show that the maximum coupler force of the combined train will decrease with the extension of the continuous exhaust time, while the total exhaust time of the controllable train-tail device remains unchanged;the maximum coupler force of the combined train reduces by32.5% with the exhaust area increasing from 70% to 140%;when the lag time between the controllable train-tail device and the master locomotive is more than 1.5 s, the maximum coupler force of the train increases along with the time difference enlargement.
基金The authors are grateful to Dr.Qing Wang(University of Kentucky,USA)for her critical reading of the manuscript.
文摘Objective:Previous studies have shown that exercise suppresses tumor growth.However,the effects of exercise with different intensities and exercise detraining after tumor-bearing on tumor progression remain unclear.The purpose of this study was to investigate the effects of continuous and disrupted free and exhausted swimming training after tumor-bearing on tumor progression in melanoma B16-F10-bearing C57BL/6 mice.Methods:C57BL/6 mice were subjected to free or exhausted swimming exercise training for 4 weeks prior to the injection of melanoma B16-F10 cells.Subsequently,the B16-F10-bearing mice were maintained with training consisting of free or exhausted swimming or without exercise for 2 weeks during the tumor challenge.Results:The tumor weight was increased by 42%and 109%in mice with 4-week exhausted swimming prior to B16-F10 tumor cells inoculation followed by 2-week training cessation compared with the tumor-bearing control(P<.05)and continuous training groups(P<.01).Tumor weights in groups with exercise detraining after tumor cell inoculation tended to be increased,while the proliferation of splenic T lymphocytes tended to be decreased compared with the group that maintained exercise intensity.After 6-weeks continuous free or exhausted swimming training,the tumor weight of mice was decreased and the proliferation of splenic T lymphocytes was increased compared with the tumor-bearing control group.The frequency of natural killer cells in tumors was increased in all exercise training groups of mice.Conclusions:These results suggest that maintaining exercise intensity after tumor-bearing slows tumor growth in mice,possibly because of the enhanced proliferative activity of splenic lymphocytes rather than natural killer cell infiltration.However,detraining after tumor-bearing might accelerate tumor progression because of the reduced proliferation of splenic T lymphocytes.
文摘Background:Doctoral students have much higher risk of anxiety or depression than general population.Doctoral students worldwide are facing varying degrees of mental health risks.Method:Based on the survey data of 6,812 doctoral students worldwide in Nature in 2019,Probit and Logit models are used to explore the correlation between thefit of doctoral education and training process and the mental health of doctoral students.Results:(1)The training environmentfit of doctoral students has a significant positive impact on their mental health.(2)The academic professionfit of doctoral students has a significant positive impact on their mental health.(3)The orga-nizational culturefit of doctoral students has a significant positive impact on their mental health.(4)Thefinancial supportfit of doctoral students has a significant positive impact on their mental health.Conclusion:The higher the degree of doctoral students’training environmentfit,academic professionfit,organizational culturefit,andfinancial supportfit,the lower the possibility of anxiety or depression among doctoral students.The current research results can help reveal extensive factors that affect the mental health of doctoral students,facilitate the planning and development of effective intervention measures by universities,improve thefit of the doctoral education and training process,improve the mental health of doctoral students,and boost academic excellence.
文摘Objective:To investigate the effect of high-intensity interval training on blood glucose control, adipocytokine secretion and oxidative stress response in patients with T2DM.Methods: A total of 92 patients with newly diagnosed T2DM who were treated in this hospital between July 2016 and July 2017 were divided into the control group (n=46) and HIIT group (n=46) by random number table method. Control group received conventional hypoglycemic therapy, HIIT group received hypoglycemic combined with high-intensity interval training therapy, and the intervention lasted for 3 months. The differences in blood glucose control, adipocytokine secretion and oxidative stress response were compared between the two groups before and after intervention.Results: Before intervention, the differences in blood glucose index levels in peripheral blood as well as the contents of adipocytokines and oxidative stress indexes in serum were not statistically significant between the two groups of patients. After 3 months of intervention, blood glucose indexes FPG, FINS and 2hPBG levels in peripheral blood of HIIT group were lower than those of control group;adipocytokine APN content in serum was higher than that of control group whereas LEP, Resistin and CHEM contents were lower than those of control group;oxidative stress indexes MDA and ROS contents in serum were lower than those of control group whereas T-AOC content was higher than that of control group. Conclusion: Routine hypoglycemic therapy combined with high-intensity interval training can further control the blood glucose levels, regulate the secretion of adipocytokines and reduce the systemic oxidative stress response.
文摘In shipping,which is one of the drivers of the world’s economy,many marine accidents continue to occur,such as ship collisions and grounding.To reduce marine collision accidents,seafarers’skills must be improved through training.Therefore,the authors propose a ship handling training for collision avoidance(hereinafter referred to as“T for CA”)in which a group of several people discusses the ship handling for collision avoidance,assuming the situation of the collision avoidance.After T for CA implementation,anchoring training was done and the effect of T for CA was verified through comparison with a group where T for CA was not applied.Two instructors evaluated the anchoring training conducted with and without“T for CA”.The anchoring training experiment showed a difference of 27.5%in the achievement rate between the proposed training and previous training.T for CA maximises the effects of group work and resulted in good evaluations in the anchoring training experiments.The training was effective because the students themselves set the scenarios and devised ship handling strategies for collision avoidance.In addition,group work discussions helped deepen students’knowledge and skills.
文摘E-learning platforms support education systems worldwide, transferring theoretical knowledge as well as soft skills. In the present study high-school pupils’, and adult students’ opinions were evaluated through a modern structured MOODLE interactive course, designed for the needs of the laboratory course “Automotive Systems”. The study concerns Greek secondary vocational education pupils aged 18 and vocational training adult students aged 20 to 50 years. The multistage, equal size simple random cluster sample was used as a sampling method. Pupils and adult students of each cluster completed structured 10-question questionnaires both before and after attending the course. A total of 120 questionnaires were collected. In general, our findings disclosed that the majority of pupils and adult students had significantly improved their knowledge and skills from using MOODLE. They reported strengthening conventional teaching, using the new MOODLE technology. The satisfaction indices improved quite, with the differences in their mean values being statistically significant.
