A new idea and a distinctive method have been proposed, which concern real errors and their estimators. By using the idea of 'Quasi-Stable Adjustment' created by Prof. Zhou Jiangwen for reference, the rank-def...A new idea and a distinctive method have been proposed, which concern real errors and their estimators. By using the idea of 'Quasi-Stable Adjustment' created by Prof. Zhou Jiangwen for reference, the rank-deficient equations on real errors are resolved by adding the conditions under which the minimum of the norm of the real errors of the quasi-accurate observations is restrained.展开更多
To satisfy the validation requirements of flight control law for advanced aircraft,a wind tunnel based virtual flight testing has been implemented in a low speed wind tunnel.A 3-degree-offreedom gimbal,ventrally insta...To satisfy the validation requirements of flight control law for advanced aircraft,a wind tunnel based virtual flight testing has been implemented in a low speed wind tunnel.A 3-degree-offreedom gimbal,ventrally installed in the model,was used in conjunction with an actively controlled dynamically similar model of aircraft,which was equipped with the inertial measurement unit,attitude and heading reference system,embedded computer and servo-actuators.The model,which could be rotated around its center of gravity freely by the aerodynamic moments,together with the flow field,operator and real time control system made up the closed-loop testing circuit.The model is statically unstable in longitudinal direction,and it can fly stably in wind tunnel with the function of control augmentation of the flight control laws.The experimental results indicate that the model responds well to the operator＇s instructions.The response of the model in the tests shows reasonable agreement with the simulation results.The difference of response of angle of attack is less than 0.5°.The effect of stability augmentation and attitude control law was validated in the test,meanwhile the feasibility of virtual flight test technique treated as preliminary evaluation tool for advanced flight vehicle configuration research was also verified.展开更多
Background:Schistosomiasis in the People’s Republic of China(PRC)can be traced back to antiquity.In the past 60 years,the Chinese government has made great efforts to control this persistent disease with elimination ...Background:Schistosomiasis in the People’s Republic of China(PRC)can be traced back to antiquity.In the past 60 years,the Chinese government has made great efforts to control this persistent disease with elimination slated by 2020 through the implementation of a comprehensive control strategy.This strategy aims to reduce the role of bovines and humans as sources of infection as a pre-requisite for elimination through transmission interruption.The goal of elimination will be achievable only by the implementation of a sustainable surveillance and control system,with sensitive diagnosis a key feature so that the true disease burden is not underestimated.Currently used diagnostics lack the necessary sensitivity to accurately determine the prevalence of Schistosoma japonicum infection in areas with low infection intensities.It is of critical importance to find and treat people and to identify animals with low-level infections if the National Control Programme for China is to achieve schistosomiasis elimination.Methods:We evaluated a real-time polymerase chain reaction(qPCR)assay using 633 human stool samples collected from five villages in Hunan,Anhui,Hubei,and Jiangxi provinces,and 182 bovine(70 cattle and 112 buffalo)stool samples obtained from four villages in Hunan,Anhui,and Jiangxi provinces in the PRC.All stool samples were subjected to the miracidium hatching test(MHT,a diagnostic procedure used in the National Schistosomiasis Control Programme)and the qPCR assay.Samples positive by MHT were subjected to either the Kato-Katz technique for humans,or the formalin-ethyl acetate sedimentation-digestion(FEA-SD)procedure for bovines,to determine infection intensities.Results:The qPCR assay exhibited a high level of sensitivity in the detection of S.japonicum infections.With both the human and bovine samples,a significantly higher prevalence was determined using the qPCR assay(11.06%humans,24.73%bovines)than with the MHT(0.93%humans,7.69%bovines).The animal contamination index(calculated using data obtained with the展开更多
文摘A new idea and a distinctive method have been proposed, which concern real errors and their estimators. By using the idea of 'Quasi-Stable Adjustment' created by Prof. Zhou Jiangwen for reference, the rank-deficient equations on real errors are resolved by adding the conditions under which the minimum of the norm of the real errors of the quasi-accurate observations is restrained.
基金supported by the National Key Basic Research Program of China(No.2015CB755800)
文摘To satisfy the validation requirements of flight control law for advanced aircraft,a wind tunnel based virtual flight testing has been implemented in a low speed wind tunnel.A 3-degree-offreedom gimbal,ventrally installed in the model,was used in conjunction with an actively controlled dynamically similar model of aircraft,which was equipped with the inertial measurement unit,attitude and heading reference system,embedded computer and servo-actuators.The model,which could be rotated around its center of gravity freely by the aerodynamic moments,together with the flow field,operator and real time control system made up the closed-loop testing circuit.The model is statically unstable in longitudinal direction,and it can fly stably in wind tunnel with the function of control augmentation of the flight control laws.The experimental results indicate that the model responds well to the operator＇s instructions.The response of the model in the tests shows reasonable agreement with the simulation results.The difference of response of angle of attack is less than 0.5°.The effect of stability augmentation and attitude control law was validated in the test,meanwhile the feasibility of virtual flight test technique treated as preliminary evaluation tool for advanced flight vehicle configuration research was also verified.
基金This work was supported by the Science and Technology Committee of Hunan Province,People’s Republic of China(Grant No.2013WK3023)by the Australian National Health and Medical Research Council(Project Grants:APP1002245,APP1098244,Program Grant:APP1037304).
文摘Background:Schistosomiasis in the People’s Republic of China(PRC)can be traced back to antiquity.In the past 60 years,the Chinese government has made great efforts to control this persistent disease with elimination slated by 2020 through the implementation of a comprehensive control strategy.This strategy aims to reduce the role of bovines and humans as sources of infection as a pre-requisite for elimination through transmission interruption.The goal of elimination will be achievable only by the implementation of a sustainable surveillance and control system,with sensitive diagnosis a key feature so that the true disease burden is not underestimated.Currently used diagnostics lack the necessary sensitivity to accurately determine the prevalence of Schistosoma japonicum infection in areas with low infection intensities.It is of critical importance to find and treat people and to identify animals with low-level infections if the National Control Programme for China is to achieve schistosomiasis elimination.Methods:We evaluated a real-time polymerase chain reaction(qPCR)assay using 633 human stool samples collected from five villages in Hunan,Anhui,Hubei,and Jiangxi provinces,and 182 bovine(70 cattle and 112 buffalo)stool samples obtained from four villages in Hunan,Anhui,and Jiangxi provinces in the PRC.All stool samples were subjected to the miracidium hatching test(MHT,a diagnostic procedure used in the National Schistosomiasis Control Programme)and the qPCR assay.Samples positive by MHT were subjected to either the Kato-Katz technique for humans,or the formalin-ethyl acetate sedimentation-digestion(FEA-SD)procedure for bovines,to determine infection intensities.Results:The qPCR assay exhibited a high level of sensitivity in the detection of S.japonicum infections.With both the human and bovine samples,a significantly higher prevalence was determined using the qPCR assay(11.06%humans,24.73%bovines)than with the MHT(0.93%humans,7.69%bovines).The animal contamination index(calculated using data obtained with the
