Based on statistics, this paper reviews China＇s economic growth and industrial upgrade since the reform and opening up in 1978 and estimates the contribution of industrial restructuring to economic growth. With the y...Based on statistics, this paper reviews China＇s economic growth and industrial upgrade since the reform and opening up in 1978 and estimates the contribution of industrial restructuring to economic growth. With the years of schooling as the proxy variable of human capital, this paper describes changes in China＇s labor competence during the industrial restructuring process. Then, this paper estimates China＇s future human capital demand and shortage based on economic and demographic forecast. Lastly, this paper proposes recommendations for improving human capital in China with skills development and education.展开更多
The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper（MMSD） biodynamic model, and the mass damper（TMD） with different op...The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper（MMSD） biodynamic model, and the mass damper（TMD） with different optimal model parameters being used to control the vertical vibration.First, the MMSD biodynamic model is employed to simulate the pedestrians, and the time-varying control equations of the vertical dynamic coupling system of the pedestrian-bridgeTMD are established with the consideration of pedestrianbridge dynamic interaction; and the equations are solved by using the Runge-Kutta-Felhberg integral method with variable step size. Secondly, the footbridge dynamic response is calculated under the model of pedestrian-structure dynamic interaction and the model of moving load when the pedestrian pace frequency is consistent with the natural frequency of footbridge. Finally, a comparative study and analysis are made on the control effects of the vertical dynamic coupling system in different optimal models of the TMD. The calculation results show that the pedestrian-bridge dynamic interaction cannot be ignored when the vertical human-induced vibration serviceability of low-frequency and light-weight footbridge is evaluated. The TMD can effectively reduce the vibration under the resonance of pedestrian-bridge, and TMD parameters are recommended for the determination by the Warburton optimization model.展开更多
Backgrounds Pulmonary arterial hypertension （PAH） was previously considered an illness that affects mostly the young, but now it is also increasingly recognized in the elderly. The aim of this study was to compare t...Backgrounds Pulmonary arterial hypertension （PAH） was previously considered an illness that affects mostly the young, but now it is also increasingly recognized in the elderly. The aim of this study was to compare the features of elderly versus younger patients diagnosed with PAH, and to define the prognostic factors which affect their long-term survival. Methods In this prospective, single center study, the clinical, echocardiographic, hemodynamic characteristics, and the outcomes of younger （18-65 years） and elderly （〉 65 years） patients with definitive diagnosis of precapillary PAIl were compared. Results A total of 119 patients were analyzed in this study; 43 were elderly （mean age： 71.5 ± 5.5 years）, while 76 were non-elderly （mean age 44.5 ±15.2 years）. During the mean follow-up duration of 26.8 ±25.0 months, 43 deaths occurred, 17 of which were among the elderly group, with 28 among non-elderly group. Comparison of baseline parameters showed that 6 min walking distance, hemoglobin levels, pulmonary artery pressures and pulmonary vascular resistance were significantly lower; and estimated glomerular filtration rate, body mass index, E/e＇ and pulmonary capillary wedge pressure were significantly higher in the elderly group than in the younger group. Survival analysis demonstrated that the independent predictors of death were tricuspid plane annular systolic excursion （TAPSE; HR： 1.272, 95% CI： 1.079-1.499, P = 0.004） and uric acid （HR： 1.291, 95% CI： 1.042-1.600, P = 0.019） in the elderly group. In contrast, in the non-elderly group, higher brain natriuretic peptide （HR： 1.002, 95% CI： 1.001-1.004, P 〈 0.001） and higher right atrial pressure （HR： 1.128, 95% CI： 1.026-1.241, P = 0.013） values were the only parameters associated with mortality. Conclusions Our data suggest that elderly PAH patients have a unique clinical and hemodynamic profile, with totally different prognostic markers compared to younger PAH patients.展开更多
Background Submaximal oxygen uptake measures are more feasible and may better predict clinical cardiac outcomes than maximal tests in older adults with heart failure （HF）. We examined relationships between maximal o...Background Submaximal oxygen uptake measures are more feasible and may better predict clinical cardiac outcomes than maximal tests in older adults with heart failure （HF）. We examined relationships between maximal oxygen uptake, submaximal oxygen kinetics, fianctional mobility, and physical activity in older adults with HF and reduced ejection fraction. Methods Older adults with HF and reduced ejection fraction （n = 25, age 75 ：i： 7 years） were compared to 25 healthy ageand gender-matched controls. Assessments included a maximal treadmill test for peak oxygen uptake （VO2p^ak）, oxygen uptake kinetics at onset of and on recovery from a submaximal treadmill test, functional mobility testing [Get Up and Go （GUG）, Comfortable Gait Speed （CGS）, Unipedal Stance （US）], and self-reported physical activity （PA）. Results Compared to controls, HF had worse performance on GUG, CGS, and US, greater delays in submaximal oxygen uptake kinetics, and lower PA. In controls, VO2peak was more strongly associated with functional mobility and PA than submaximal oxygen uptake kinetics. In HF patients, submaximal oxygen uptake kinetics were similarly associated with GUG and CGS as VO2peak, but weakly associated with PA. Conclusions Based on their mobility performance, older HF patients with reduced ejection fraction are at risk for adverse functional outcomes. In this population, submaximal oxygen uptake measures may be equivalent to VO2 peak in predicting functional mobility, and in addition to being more feasible, may provide better insight into how aerobic function relates to mobility in older adults with HF.展开更多
In order to mitigate the effects of space adaptation syndrome(SAS) and improve the training efficiency of the astronauts, a novel astronaut rehabilitative training robot(ART) was proposed. ART can help the astronauts ...In order to mitigate the effects of space adaptation syndrome(SAS) and improve the training efficiency of the astronauts, a novel astronaut rehabilitative training robot(ART) was proposed. ART can help the astronauts to carry out the bench press training in the microgravity environment. Firstly, a dynamic model of cable driven unit(CDU) was established whose accuracy was verified through the model identification. Secondly, to improve the accuracy and the speed of the active loading, an active loading hybrid force controller was proposed on the basis of the dynamic model of the CDU. Finally, the actual effect of the hybrid force controller was tested by simulations and experiments. The results suggest that the hybrid force controller can significantly improve the precision and the dynamic performance of the active loading with the maximum phase lag of the active loading being 9° and the maximum amplitude error being 2% at the frequency range of 10 Hz. The controller can meet the design requirements.展开更多
As a new group in the process of socio-economic transformation, female members of the Chinese floating population have negative self-identities rooted in the traditional gender discrimination in China society. This im...As a new group in the process of socio-economic transformation, female members of the Chinese floating population have negative self-identities rooted in the traditional gender discrimination in China society. This impacts negatively on female migrants1 both physiologically and psychologically, disadvantaging them in the pursuit of resources, opportunities and rights. It is therefore necessary to positively influence the self-image of female migrants so as to ensure their rights, further their interests and ultimately to achieve gender equality.展开更多
Background：Little is known about change in physical activity（PA） and its relationship to all-cause mortality among old people.There is even less information about the association between PA,fitness and all-cause mo...Background：Little is known about change in physical activity（PA） and its relationship to all-cause mortality among old people.There is even less information about the association between PA,fitness and all-cause mortality among people aged 80 years and above.The objective is to investigate persistence and change in PA over 5 years as a predictor of all-cause mortality,and fitnes as a mediator of this association,among people aged 80 and 85 years at the beginning of an 18-year mortality follow-up period.Methods：Using Evergreen Project data（started in 1989）,4 study groups were formed according to self-reported changes in PA level,over a 5-year period（starting in 1989–1990 and ending in 1994–1995）：remained active（RA,control group）,changed to inactive（CI）,remained inactive（RI）,and changed to active（CA）.Mortality was followed up over the 18-year period（1994–2012）.Cox models with different covariates such as age,sex,use of alcohol,smoking,chronic diseases,and a 10 m walking test were used to analyze the association between change in PA level and mortality.Results：Compared to RA,those who decreased their PA level（CI） between baseline and follow-up had higher all-cause mortality（hazard ratio（HR=2.09;95%CI：1.63–2.69） when adjusted for age,gender,and chronic diseases.RI showed the highest all-cause mortality（HR = 2.16;95%CI：1.59–2.93）.In CA,when compared against RA,the risk of all-cause mortality was not statistically significan（HR=1.51;95%CI：0.95–2.38）.In comparison with RA,when walking speed over 10 m was added as a covariate,all-cause mortality risk was almost statistically significan only in CI（HR=1.37;95%CI：1.00–1.87）.Conclusion：Persistence and change in PA level was associated with mortality.This association was largely explained by fitnes status.Randomized controlled studies are needed to test whether maintaining or increasing PA level could lengthen the life of old people.展开更多
This article reports a particle image velocimetry study and the comparative results of a numerical simulation into the hydrodynamic characteristics around an artificial reef.We reveal the process of flow separation an...This article reports a particle image velocimetry study and the comparative results of a numerical simulation into the hydrodynamic characteristics around an artificial reef.We reveal the process of flow separation and vortex evolution,and compare the force terms generated by our artificial reef model.The numerical simulation agrees well with experimental results,showing the applicability of computational fluid dynamics to the hydrodynamics of an artificial reef.Furthermore,we numerically simulate the hydrodynamics of the reef model for seven velocities.The results show that the drag coefficient is approximately 1.21 in a self-modeling region for Reynolds numbers between 2.123×104and 9×104.Therefore,the upwelling height and current width of the flow field do not change significantly when the inflow velocity increases.Our study indicates that computational fluid dynamics can be applied to study the hydrodynamics of an artificial reef and offer clues to its construction.展开更多
文摘Based on statistics, this paper reviews China＇s economic growth and industrial upgrade since the reform and opening up in 1978 and estimates the contribution of industrial restructuring to economic growth. With the years of schooling as the proxy variable of human capital, this paper describes changes in China＇s labor competence during the industrial restructuring process. Then, this paper estimates China＇s future human capital demand and shortage based on economic and demographic forecast. Lastly, this paper proposes recommendations for improving human capital in China with skills development and education.
基金The National Natural Science Foundation of China(No.51508257,51668042,51578274)the Yangtze River Scholar and the Innovation Team of M inistry of Education(No.IRT13068)the Scientific Research Project of Gansu Higher Education(No.2015B-34)
文摘The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper（MMSD） biodynamic model, and the mass damper（TMD） with different optimal model parameters being used to control the vertical vibration.First, the MMSD biodynamic model is employed to simulate the pedestrians, and the time-varying control equations of the vertical dynamic coupling system of the pedestrian-bridgeTMD are established with the consideration of pedestrianbridge dynamic interaction; and the equations are solved by using the Runge-Kutta-Felhberg integral method with variable step size. Secondly, the footbridge dynamic response is calculated under the model of pedestrian-structure dynamic interaction and the model of moving load when the pedestrian pace frequency is consistent with the natural frequency of footbridge. Finally, a comparative study and analysis are made on the control effects of the vertical dynamic coupling system in different optimal models of the TMD. The calculation results show that the pedestrian-bridge dynamic interaction cannot be ignored when the vertical human-induced vibration serviceability of low-frequency and light-weight footbridge is evaluated. The TMD can effectively reduce the vibration under the resonance of pedestrian-bridge, and TMD parameters are recommended for the determination by the Warburton optimization model.
文摘Backgrounds Pulmonary arterial hypertension （PAH） was previously considered an illness that affects mostly the young, but now it is also increasingly recognized in the elderly. The aim of this study was to compare the features of elderly versus younger patients diagnosed with PAH, and to define the prognostic factors which affect their long-term survival. Methods In this prospective, single center study, the clinical, echocardiographic, hemodynamic characteristics, and the outcomes of younger （18-65 years） and elderly （〉 65 years） patients with definitive diagnosis of precapillary PAIl were compared. Results A total of 119 patients were analyzed in this study; 43 were elderly （mean age： 71.5 ± 5.5 years）, while 76 were non-elderly （mean age 44.5 ±15.2 years）. During the mean follow-up duration of 26.8 ±25.0 months, 43 deaths occurred, 17 of which were among the elderly group, with 28 among non-elderly group. Comparison of baseline parameters showed that 6 min walking distance, hemoglobin levels, pulmonary artery pressures and pulmonary vascular resistance were significantly lower; and estimated glomerular filtration rate, body mass index, E/e＇ and pulmonary capillary wedge pressure were significantly higher in the elderly group than in the younger group. Survival analysis demonstrated that the independent predictors of death were tricuspid plane annular systolic excursion （TAPSE; HR： 1.272, 95% CI： 1.079-1.499, P = 0.004） and uric acid （HR： 1.291, 95% CI： 1.042-1.600, P = 0.019） in the elderly group. In contrast, in the non-elderly group, higher brain natriuretic peptide （HR： 1.002, 95% CI： 1.001-1.004, P 〈 0.001） and higher right atrial pressure （HR： 1.128, 95% CI： 1.026-1.241, P = 0.013） values were the only parameters associated with mortality. Conclusions Our data suggest that elderly PAH patients have a unique clinical and hemodynamic profile, with totally different prognostic markers compared to younger PAH patients.
文摘Background Submaximal oxygen uptake measures are more feasible and may better predict clinical cardiac outcomes than maximal tests in older adults with heart failure （HF）. We examined relationships between maximal oxygen uptake, submaximal oxygen kinetics, fianctional mobility, and physical activity in older adults with HF and reduced ejection fraction. Methods Older adults with HF and reduced ejection fraction （n = 25, age 75 ：i： 7 years） were compared to 25 healthy ageand gender-matched controls. Assessments included a maximal treadmill test for peak oxygen uptake （VO2p^ak）, oxygen uptake kinetics at onset of and on recovery from a submaximal treadmill test, functional mobility testing [Get Up and Go （GUG）, Comfortable Gait Speed （CGS）, Unipedal Stance （US）], and self-reported physical activity （PA）. Results Compared to controls, HF had worse performance on GUG, CGS, and US, greater delays in submaximal oxygen uptake kinetics, and lower PA. In controls, VO2peak was more strongly associated with functional mobility and PA than submaximal oxygen uptake kinetics. In HF patients, submaximal oxygen uptake kinetics were similarly associated with GUG and CGS as VO2peak, but weakly associated with PA. Conclusions Based on their mobility performance, older HF patients with reduced ejection fraction are at risk for adverse functional outcomes. In this population, submaximal oxygen uptake measures may be equivalent to VO2 peak in predicting functional mobility, and in addition to being more feasible, may provide better insight into how aerobic function relates to mobility in older adults with HF.
基金Project(61175128) supported by the National Natural Science Foundation of ChinaProject(2008AA040203) supported by the National High Technology Research and Development Program of ChinaProject(QC2010009) supported by the Natural Science Foundation of Heilongjiang Province,China
文摘In order to mitigate the effects of space adaptation syndrome(SAS) and improve the training efficiency of the astronauts, a novel astronaut rehabilitative training robot(ART) was proposed. ART can help the astronauts to carry out the bench press training in the microgravity environment. Firstly, a dynamic model of cable driven unit(CDU) was established whose accuracy was verified through the model identification. Secondly, to improve the accuracy and the speed of the active loading, an active loading hybrid force controller was proposed on the basis of the dynamic model of the CDU. Finally, the actual effect of the hybrid force controller was tested by simulations and experiments. The results suggest that the hybrid force controller can significantly improve the precision and the dynamic performance of the active loading with the maximum phase lag of the active loading being 9° and the maximum amplitude error being 2% at the frequency range of 10 Hz. The controller can meet the design requirements.
文摘As a new group in the process of socio-economic transformation, female members of the Chinese floating population have negative self-identities rooted in the traditional gender discrimination in China society. This impacts negatively on female migrants1 both physiologically and psychologically, disadvantaging them in the pursuit of resources, opportunities and rights. It is therefore necessary to positively influence the self-image of female migrants so as to ensure their rights, further their interests and ultimately to achieve gender equality.
文摘Background：Little is known about change in physical activity（PA） and its relationship to all-cause mortality among old people.There is even less information about the association between PA,fitness and all-cause mortality among people aged 80 years and above.The objective is to investigate persistence and change in PA over 5 years as a predictor of all-cause mortality,and fitnes as a mediator of this association,among people aged 80 and 85 years at the beginning of an 18-year mortality follow-up period.Methods：Using Evergreen Project data（started in 1989）,4 study groups were formed according to self-reported changes in PA level,over a 5-year period（starting in 1989–1990 and ending in 1994–1995）：remained active（RA,control group）,changed to inactive（CI）,remained inactive（RI）,and changed to active（CA）.Mortality was followed up over the 18-year period（1994–2012）.Cox models with different covariates such as age,sex,use of alcohol,smoking,chronic diseases,and a 10 m walking test were used to analyze the association between change in PA level and mortality.Results：Compared to RA,those who decreased their PA level（CI） between baseline and follow-up had higher all-cause mortality（hazard ratio（HR=2.09;95%CI：1.63–2.69） when adjusted for age,gender,and chronic diseases.RI showed the highest all-cause mortality（HR = 2.16;95%CI：1.59–2.93）.In CA,when compared against RA,the risk of all-cause mortality was not statistically significan（HR=1.51;95%CI：0.95–2.38）.In comparison with RA,when walking speed over 10 m was added as a covariate,all-cause mortality risk was almost statistically significan only in CI（HR=1.37;95%CI：1.00–1.87）.Conclusion：Persistence and change in PA level was associated with mortality.This association was largely explained by fitnes status.Randomized controlled studies are needed to test whether maintaining or increasing PA level could lengthen the life of old people.
基金Supported by the National Natural Science Foundation of China(Nos.31072246,31272703)
文摘This article reports a particle image velocimetry study and the comparative results of a numerical simulation into the hydrodynamic characteristics around an artificial reef.We reveal the process of flow separation and vortex evolution,and compare the force terms generated by our artificial reef model.The numerical simulation agrees well with experimental results,showing the applicability of computational fluid dynamics to the hydrodynamics of an artificial reef.Furthermore,we numerically simulate the hydrodynamics of the reef model for seven velocities.The results show that the drag coefficient is approximately 1.21 in a self-modeling region for Reynolds numbers between 2.123×104and 9×104.Therefore,the upwelling height and current width of the flow field do not change significantly when the inflow velocity increases.Our study indicates that computational fluid dynamics can be applied to study the hydrodynamics of an artificial reef and offer clues to its construction.
