In order to interpret the physical feature of Bessho form translating-pulsating source Green function, the phase function is extracted from the integral representation and stationary-phase analysis is carried out in t...In order to interpret the physical feature of Bessho form translating-pulsating source Green function, the phase function is extracted from the integral representation and stationary-phase analysis is carried out in this paper. The complex characteristics of the integral variable and segmentation of the integral intervals are discussed in m complex plane. In θ space, the interval [-π/2+φ,-π/2+φ-iε] is dominant in the near-field flow, and there is a one-to-one correspondence between the real intervals in m space and the unsteady wave patterns in far field. If 4τ>1(τ is the Brard number), there are three kinds of propagation wave patterns such as ring-fan wave pattern, fan wave pattern and inner V wave pattern, and if 0<4τ<1, a ring wave pattern, an outer V and inner V wave pattern are presented in far field. The ring-fan or ring wave pattern corresponds to the interval [-π+α,-π/2+φ] for integral terms about k2, and the fan or outer V wave pattern and inner V wave pattern correspond to [-π+α,-π/2) and(-π/2,-π/2+φ] respectively for terms about k1. Numerical result shows that it is beneficial to decompose the unsteady wave patterns under the condition of τ≠0 by converting the integral variable θ to m. In addition, the constant-phase curve equations are derived when the source is performing only pulsating or translating.展开更多
Using predictions for the sea surface temperature anomaly(SSTA) generated by an intermediate coupled model(ICM)ensemble prediction system(EPS), we first explore the "spring predictability barrier"(SPB) probl...Using predictions for the sea surface temperature anomaly(SSTA) generated by an intermediate coupled model(ICM)ensemble prediction system(EPS), we first explore the "spring predictability barrier"(SPB) problem for the 2015/16 strong El Nio event from the perspective of error growth. By analyzing the growth tendency of the prediction errors for ensemble forecast members, we conclude that the prediction errors for the 2015/16 El Nio event tended to show a distinct season-dependent evolution, with prominent growth in spring and/or the beginning of the summer. This finding indicates that the predictions for the 2015/16 El Nio occurred a significant SPB phenomenon. We show that the SPB occurred in the 2015/16 El Nio predictions did not arise because of the uncertainties in the initial conditions but because of model errors. As such, the mean of ensemble forecast members filtered the effect of model errors and weakened the effect of the SPB, ultimately reducing the prediction errors for the 2015/16 El Nio event. By investigating the model errors represented by the tendency errors for the SSTA component,we demonstrate the prominent features of the tendency errors that often cause an SPB for the 2015/16 El Nio event and explain why the 2015/16 El Nio was under-predicted by the ICM EPS. Moreover, we reveal the typical feature of the tendency errors that cause not only a significant SPB but also an aggressively large prediction error. The feature is that the tendency errors present a zonal dipolar pattern with the west poles of positive anomalies in the equatorial western Pacific and the east poles of negative anomalies in the equatorial eastern Pacific. This tendency error bears great similarities with that of the most sensitive nonlinear forcing singular vector(NFSV)-tendency errors reported by Duan et al. and demonstrates the existence of an NFSV tendency error in realistic predictions. For other strong El Nio events, such as those that occurred in 1982/83 and 1997/98, we obtain the tendency errors of the NFSV structure, which cause a significant SPB and yield a much larger prediction error. These results suggest that the forecast skill of the ICM EPS for strong El Nio events could be greatly enhanced by using the NFSV-like tendency error to correct the model.展开更多
One recent study by using instrumental records suggested the correlation between East Asian surface air temperatures(EATs)and the Atlantic Multidecadal Oscillation(AMO)reaches the maximum when the former leads the lat...One recent study by using instrumental records suggested the correlation between East Asian surface air temperatures(EATs)and the Atlantic Multidecadal Oscillation(AMO)reaches the maximum when the former leads the latter by 5–7 years.This seems to disagree with a previous well-realized point that the AMO modulates the decadal variation of EATs,since the atmosphere responds swiftly to sea surface temperature anomalies(SSTA)if therein.It implies that the AMO-EATs correlation should reach the maximum when they are simultaneous or the AMO leads EATs slightly,rather than that the EATs lead the AMO.Thus,this poses an issue about the reality of the newly found lead-lag correlation.Because the instrumental record in the natural climate system may be contaminated by human activities,the EATs-AMO lead-lag correlation derived from the instrumental records may not be a realistic connection of the natural climate system.Thus,whether the connection also exists in the proxies prior to the industrial is essential to answer the issue.In this study the EATs-AMO lead-lag connection is analyzed by using the reconstructed data in the last 500 years,together with the control experimental data with the prescribed pre-industrial forcing in a multiple of coupled climate system models,which attend the international CMIP5 program.The results suggest that the connection,the EATs lead the AMO,also exists in the period from the Little Ice Age(LIA)to the industrial,1500–1860AD.Therefore,the connection may be realistic in the natural climate system.The mechanisms for the connection are then discussed briefly.The results from this paper provide some insights into the connection of the AMO with East Asian climate.展开更多
Objective: To investigate the community promotion feasibility of superficial needling plus club swing for post-stroke motion impairment of the shoulder joint. Methods:A total of 180 cases (duration 〈1.5 years) wi...Objective: To investigate the community promotion feasibility of superficial needling plus club swing for post-stroke motion impairment of the shoulder joint. Methods:A total of 180 cases (duration 〈1.5 years) with post-stroke motion impairment of the shoulder joint were recruited from three community health centers in Changning District, 60 from each community. They were randomly allocated into an observation group (n=90) and a control group (n=90). Patients in both groups received standard internal and rehabilitation care. Patients in the observation group received additional superficial needling plus club swing. The visual analogue scale (VAS) was conducted before and 60 d after the treatment to evaluate the severity of shoulder pain. The active movement of the shoulder joint and activities of daily living (ADL) were also observed. Results:There were no between-group statistical differences before the treatment (allP〉0.05). After a 60-day treatment, the shoulder pain severity, active range of motion of the shoulder joint and ADL in the observation group were significantly improved than those in the control group (allP〈0.01). In addition, no adverse events were reported by participants in the observation group. Conclusion:Superficial needling plus club swing plays a positive role in improving post-stroke motion impairment of the shoulder joint. This safe, reliable and economical therapy has good patient compliance and is suitable for community promotion.展开更多
基金financial support from the National Natural Science Foundation of China under Grant No. 50879090the Key Program of Hydrodynamics of China under Grant No.9140A14030712JB11044
文摘In order to interpret the physical feature of Bessho form translating-pulsating source Green function, the phase function is extracted from the integral representation and stationary-phase analysis is carried out in this paper. The complex characteristics of the integral variable and segmentation of the integral intervals are discussed in m complex plane. In θ space, the interval [-π/2+φ,-π/2+φ-iε] is dominant in the near-field flow, and there is a one-to-one correspondence between the real intervals in m space and the unsteady wave patterns in far field. If 4τ>1(τ is the Brard number), there are three kinds of propagation wave patterns such as ring-fan wave pattern, fan wave pattern and inner V wave pattern, and if 0<4τ<1, a ring wave pattern, an outer V and inner V wave pattern are presented in far field. The ring-fan or ring wave pattern corresponds to the interval [-π+α,-π/2+φ] for integral terms about k2, and the fan or outer V wave pattern and inner V wave pattern correspond to [-π+α,-π/2) and(-π/2,-π/2+φ] respectively for terms about k1. Numerical result shows that it is beneficial to decompose the unsteady wave patterns under the condition of τ≠0 by converting the integral variable θ to m. In addition, the constant-phase curve equations are derived when the source is performing only pulsating or translating.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41230420 & 41525017)the National Public Benefit (Meteorology) Research Foundation of China (Grant No. GYHY201306018)
文摘Using predictions for the sea surface temperature anomaly(SSTA) generated by an intermediate coupled model(ICM)ensemble prediction system(EPS), we first explore the "spring predictability barrier"(SPB) problem for the 2015/16 strong El Nio event from the perspective of error growth. By analyzing the growth tendency of the prediction errors for ensemble forecast members, we conclude that the prediction errors for the 2015/16 El Nio event tended to show a distinct season-dependent evolution, with prominent growth in spring and/or the beginning of the summer. This finding indicates that the predictions for the 2015/16 El Nio occurred a significant SPB phenomenon. We show that the SPB occurred in the 2015/16 El Nio predictions did not arise because of the uncertainties in the initial conditions but because of model errors. As such, the mean of ensemble forecast members filtered the effect of model errors and weakened the effect of the SPB, ultimately reducing the prediction errors for the 2015/16 El Nio event. By investigating the model errors represented by the tendency errors for the SSTA component,we demonstrate the prominent features of the tendency errors that often cause an SPB for the 2015/16 El Nio event and explain why the 2015/16 El Nio was under-predicted by the ICM EPS. Moreover, we reveal the typical feature of the tendency errors that cause not only a significant SPB but also an aggressively large prediction error. The feature is that the tendency errors present a zonal dipolar pattern with the west poles of positive anomalies in the equatorial western Pacific and the east poles of negative anomalies in the equatorial eastern Pacific. This tendency error bears great similarities with that of the most sensitive nonlinear forcing singular vector(NFSV)-tendency errors reported by Duan et al. and demonstrates the existence of an NFSV tendency error in realistic predictions. For other strong El Nio events, such as those that occurred in 1982/83 and 1997/98, we obtain the tendency errors of the NFSV structure, which cause a significant SPB and yield a much larger prediction error. These results suggest that the forecast skill of the ICM EPS for strong El Nio events could be greatly enhanced by using the NFSV-like tendency error to correct the model.
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.41375085,41421004)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA05090406)
文摘One recent study by using instrumental records suggested the correlation between East Asian surface air temperatures(EATs)and the Atlantic Multidecadal Oscillation(AMO)reaches the maximum when the former leads the latter by 5–7 years.This seems to disagree with a previous well-realized point that the AMO modulates the decadal variation of EATs,since the atmosphere responds swiftly to sea surface temperature anomalies(SSTA)if therein.It implies that the AMO-EATs correlation should reach the maximum when they are simultaneous or the AMO leads EATs slightly,rather than that the EATs lead the AMO.Thus,this poses an issue about the reality of the newly found lead-lag correlation.Because the instrumental record in the natural climate system may be contaminated by human activities,the EATs-AMO lead-lag correlation derived from the instrumental records may not be a realistic connection of the natural climate system.Thus,whether the connection also exists in the proxies prior to the industrial is essential to answer the issue.In this study the EATs-AMO lead-lag connection is analyzed by using the reconstructed data in the last 500 years,together with the control experimental data with the prescribed pre-industrial forcing in a multiple of coupled climate system models,which attend the international CMIP5 program.The results suggest that the connection,the EATs lead the AMO,also exists in the period from the Little Ice Age(LIA)to the industrial,1500–1860AD.Therefore,the connection may be realistic in the natural climate system.The mechanisms for the connection are then discussed briefly.The results from this paper provide some insights into the connection of the AMO with East Asian climate.
基金supported by Appropriate Technology of Traditional Chinese Medicine Promotion Project in the Community of Shanghai No.ZYSNXD-YL-SYJS-2Special Project of Science and Technology Committee of Changning District in Shanghai No.CNKW2014J06~~
文摘Objective: To investigate the community promotion feasibility of superficial needling plus club swing for post-stroke motion impairment of the shoulder joint. Methods:A total of 180 cases (duration 〈1.5 years) with post-stroke motion impairment of the shoulder joint were recruited from three community health centers in Changning District, 60 from each community. They were randomly allocated into an observation group (n=90) and a control group (n=90). Patients in both groups received standard internal and rehabilitation care. Patients in the observation group received additional superficial needling plus club swing. The visual analogue scale (VAS) was conducted before and 60 d after the treatment to evaluate the severity of shoulder pain. The active movement of the shoulder joint and activities of daily living (ADL) were also observed. Results:There were no between-group statistical differences before the treatment (allP〉0.05). After a 60-day treatment, the shoulder pain severity, active range of motion of the shoulder joint and ADL in the observation group were significantly improved than those in the control group (allP〈0.01). In addition, no adverse events were reported by participants in the observation group. Conclusion:Superficial needling plus club swing plays a positive role in improving post-stroke motion impairment of the shoulder joint. This safe, reliable and economical therapy has good patient compliance and is suitable for community promotion.