Through system analysis of typical explosive trains in various fuses, physical and correspondent mathematical models of typical explosive trains are established, based on mass conservation, momentum conservation, ener...Through system analysis of typical explosive trains in various fuses, physical and correspondent mathematical models of typical explosive trains are established, based on mass conservation, momentum conservation, energy conservation and so on. MAZE and DYNA2D program is used to dispose these models and results of the simulating of elements of explosive trains in a typical fuse are obtained. It is helpful for designing fuses.展开更多
BACKGROUND： Plyometric training has been shown to improve performance in distance running events up to 5-km, but little research has been done on this type of training for marathon （42.195-km） runners. The purpose ...BACKGROUND： Plyometric training has been shown to improve performance in distance running events up to 5-km, but little research has been done on this type of training for marathon （42.195-km） runners. The purpose of this study was to examine the effects of plyometric and explosive speed training （PLYO） on recreational marathoners. METHODS： Twenty-two subjects （ages 18-23）, were randomized to either PLYO or core training （CORE） for a weekly session performed for 12 weeks, in addition to marathon training. Sprint, jump, and distance running performance variables were measured pre- and post-intervention. RESULTS： In the sprint tests, the PLYO group improved in both the 200-m run （P ≤ 0.001） and 60-m run （P = 0.004）, and trended toward improvement in the 30-m fly （P = 0.051）. The difference from CORE was significant only in the 200-m （P = 0.002）. The CORE group did not change in any of the sprint or jump variables. The PLYO group was significantly different from the CORE group in the standing long jump （P = 0.024）. There were no differences between groups in distance running performance. Both improved in 2-mile （3.219-km） time trial （p 〈 0.001）, VO2MAX （P = 0.026 for CORE; P = 0.002 for PLYO）, and running economy （P = 0.01）. CONCLUSION： Weekly PLYO training improves sprint speed and maintains jumping ability in recreational marathoners, but does not augment improvements in distance running performance.展开更多
The shot put is a sport that requires very high explosive power and precise technique.Strength training occupies the core position in the training of shot-putters,which can not only improve the throwing distance of at...The shot put is a sport that requires very high explosive power and precise technique.Strength training occupies the core position in the training of shot-putters,which can not only improve the throwing distance of athletes but also enhance their competitive state and prevent sports injuries.The purpose of this paper is to analyze the principles,classification,methods,and specific exercises of strength training in the training of shot-putters,in order to provide scientific training guidance for shot-putters.展开更多
Purpose:The purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.Methods:Fourteen moderately trained male endurance runners were all...Purpose:The purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.Methods:Fourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group(n = 7)or the plyometric training group(n = 7).The preliminary tests required subjects to perform a treadmill graded exercise test,a countermovement jump test for peak power measurement,and a 10-km time trial.Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week.On completion of the intervention,post-tests were conducted.Results:Both groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period.There were significant improvements in the 10-km time trial performance and peak power.There was also significant improvement in relative peak power for both groups.The 10-km time trial performance and relative peak power showed a moderate inverse correlation.Conclusion:These findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage.The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.展开更多
Purpose:It is challenging to prepare military surgeons with the skills of combat damage control surgery(CDCS).The current study aimed to establish a damage control surgery(DCS)training platform for explosive combined ...Purpose:It is challenging to prepare military surgeons with the skills of combat damage control surgery(CDCS).The current study aimed to establish a damage control surgery(DCS)training platform for explosive combined thoraco-abdominal injuries.Methods:The training platform established in this study consisted of 3 main components:(1)A 50 m×50 m square yard was constructed as the explosion site.Safety was assessed through cameras.(2)Sixteen pigs were injured by an explosion of trinitrotoluene attached with steel balls and were randomly divided into the DCS group(accepted DCS)and the control group(have not accepted DCS).The mortality rate was observed.(3)The literature was reviewed to identify the key factors for assessing CDCS,and testing standards for CDCS were then established.Expert questionnaires were employed to evaluate the scientificity and feasibility of the testing standards.Then,a 5-day training course with incorporated tests was used to test the efficacy of the established platform.In total,30 teams attended the first training course.The scores that the trainees received before and after the training were compared.SPSS 11.0 was employed to analyze the results.Results:The high-speed video playback confirmed the safety of the explosion site as no explosion fragments projected beyond the wall.No pig died within 24 h when DCS was performed,while 7 pigs died in the control group.After a literature review,assessment criteria for CDCS were established that had a total score of 100 points and had 4 major parts:leadership and team cooperation,resuscitation,surgical procedure,and final outcome.Expert questionnaire results showed that the scientific score was 8.6±1.25,and the feasibility score was 8.74±1.19.When compared with the basic level,the trainees’score improved significantly after training.展开更多
文摘Through system analysis of typical explosive trains in various fuses, physical and correspondent mathematical models of typical explosive trains are established, based on mass conservation, momentum conservation, energy conservation and so on. MAZE and DYNA2D program is used to dispose these models and results of the simulating of elements of explosive trains in a typical fuse are obtained. It is helpful for designing fuses.
文摘BACKGROUND： Plyometric training has been shown to improve performance in distance running events up to 5-km, but little research has been done on this type of training for marathon （42.195-km） runners. The purpose of this study was to examine the effects of plyometric and explosive speed training （PLYO） on recreational marathoners. METHODS： Twenty-two subjects （ages 18-23）, were randomized to either PLYO or core training （CORE） for a weekly session performed for 12 weeks, in addition to marathon training. Sprint, jump, and distance running performance variables were measured pre- and post-intervention. RESULTS： In the sprint tests, the PLYO group improved in both the 200-m run （P ≤ 0.001） and 60-m run （P = 0.004）, and trended toward improvement in the 30-m fly （P = 0.051）. The difference from CORE was significant only in the 200-m （P = 0.002）. The CORE group did not change in any of the sprint or jump variables. The PLYO group was significantly different from the CORE group in the standing long jump （P = 0.024）. There were no differences between groups in distance running performance. Both improved in 2-mile （3.219-km） time trial （p 〈 0.001）, VO2MAX （P = 0.026 for CORE; P = 0.002 for PLYO）, and running economy （P = 0.01）. CONCLUSION： Weekly PLYO training improves sprint speed and maintains jumping ability in recreational marathoners, but does not augment improvements in distance running performance.
文摘The shot put is a sport that requires very high explosive power and precise technique.Strength training occupies the core position in the training of shot-putters,which can not only improve the throwing distance of athletes but also enhance their competitive state and prevent sports injuries.The purpose of this paper is to analyze the principles,classification,methods,and specific exercises of strength training in the training of shot-putters,in order to provide scientific training guidance for shot-putters.
文摘Purpose:The purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.Methods:Fourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group(n = 7)or the plyometric training group(n = 7).The preliminary tests required subjects to perform a treadmill graded exercise test,a countermovement jump test for peak power measurement,and a 10-km time trial.Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week.On completion of the intervention,post-tests were conducted.Results:Both groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period.There were significant improvements in the 10-km time trial performance and peak power.There was also significant improvement in relative peak power for both groups.The 10-km time trial performance and relative peak power showed a moderate inverse correlation.Conclusion:These findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage.The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.
基金Key logistics scientific project of the "Thirteenth Five Year Plan" of Medical Research of PLA(ALJ19J001)Key Clinical Innovation Project of XinQiao Hospital and Army Medical University(2018JSLC0023/CX2019JS107)
文摘Purpose:It is challenging to prepare military surgeons with the skills of combat damage control surgery(CDCS).The current study aimed to establish a damage control surgery(DCS)training platform for explosive combined thoraco-abdominal injuries.Methods:The training platform established in this study consisted of 3 main components:(1)A 50 m×50 m square yard was constructed as the explosion site.Safety was assessed through cameras.(2)Sixteen pigs were injured by an explosion of trinitrotoluene attached with steel balls and were randomly divided into the DCS group(accepted DCS)and the control group(have not accepted DCS).The mortality rate was observed.(3)The literature was reviewed to identify the key factors for assessing CDCS,and testing standards for CDCS were then established.Expert questionnaires were employed to evaluate the scientificity and feasibility of the testing standards.Then,a 5-day training course with incorporated tests was used to test the efficacy of the established platform.In total,30 teams attended the first training course.The scores that the trainees received before and after the training were compared.SPSS 11.0 was employed to analyze the results.Results:The high-speed video playback confirmed the safety of the explosion site as no explosion fragments projected beyond the wall.No pig died within 24 h when DCS was performed,while 7 pigs died in the control group.After a literature review,assessment criteria for CDCS were established that had a total score of 100 points and had 4 major parts:leadership and team cooperation,resuscitation,surgical procedure,and final outcome.Expert questionnaire results showed that the scientific score was 8.6±1.25,and the feasibility score was 8.74±1.19.When compared with the basic level,the trainees’score improved significantly after training.
