A consequence of nonlinearities is a multi-harmonic response via a monoharmonic excitation.A similar phenomenon also exists in random vibration.The power spectral density(PSD)analysis of random vibration for nonlinear...A consequence of nonlinearities is a multi-harmonic response via a monoharmonic excitation.A similar phenomenon also exists in random vibration.The power spectral density(PSD)analysis of random vibration for nonlinear systems is studied in this paper.The analytical formulation of output PSD subject to the zero-mean Gaussian random load is deduced by using the Volterra series expansion and the conception of generalized frequency response function(GFRF).For a class of nonlinear systems,the growing exponential method is used to determine the first 3 rd-order GFRFs.The proposed approach is used to achieve the nonlinear system’s output PSD under a narrow-band stationary random input.The relationship between the peak of PSD and the parameters of the nonlinear system is discussed.By using the proposed method,the nonlinear characteristics of multi-band output via single-band input can be well predicted.The results reveal that changing nonlinear system parameters gives a one-of-a-kind change of the system’s output PSD.This paper provides a method for the research of random vibration prediction and control in real-world nonlinear systems.展开更多
To the Editor:Patients with severe persistent asthma experience greater morbidity with more impairment in quality of life despite higher use of health care resources and being treated with existing asthma treatments s...To the Editor:Patients with severe persistent asthma experience greater morbidity with more impairment in quality of life despite higher use of health care resources and being treated with existing asthma treatments such as inhaled corticosteroids and b-agonists,and sometimes oral corticosteroid(OCS)therapy.Type-2(T2)high asthma has been identified as a phenotype that responds to targeted T2 biologic therapies such as anti-IgE,anti-interleukin(IL)5,or anti-IL5Ra and anti-IL4Ra monoclonal antibodies,which are currently available in Europe and North America,and are currently introduced in the rest of the world.[1]展开更多
基金the National Natural Science Foundation of China(Nos.11772084 and U1906233)the National High Technology Research and Development Program of China(No.2017YFC0307203)the Key Technology Research and Development Program of Shandong Province of China(No.2019JZZY010801)。
文摘A consequence of nonlinearities is a multi-harmonic response via a monoharmonic excitation.A similar phenomenon also exists in random vibration.The power spectral density(PSD)analysis of random vibration for nonlinear systems is studied in this paper.The analytical formulation of output PSD subject to the zero-mean Gaussian random load is deduced by using the Volterra series expansion and the conception of generalized frequency response function(GFRF).For a class of nonlinear systems,the growing exponential method is used to determine the first 3 rd-order GFRFs.The proposed approach is used to achieve the nonlinear system’s output PSD under a narrow-band stationary random input.The relationship between the peak of PSD and the parameters of the nonlinear system is discussed.By using the proposed method,the nonlinear characteristics of multi-band output via single-band input can be well predicted.The results reveal that changing nonlinear system parameters gives a one-of-a-kind change of the system’s output PSD.This paper provides a method for the research of random vibration prediction and control in real-world nonlinear systems.
基金supported by grants from AstraZeneca,China,and the National Natural Science Foundation of China(No.82070026).
文摘To the Editor:Patients with severe persistent asthma experience greater morbidity with more impairment in quality of life despite higher use of health care resources and being treated with existing asthma treatments such as inhaled corticosteroids and b-agonists,and sometimes oral corticosteroid(OCS)therapy.Type-2(T2)high asthma has been identified as a phenotype that responds to targeted T2 biologic therapies such as anti-IgE,anti-interleukin(IL)5,or anti-IL5Ra and anti-IL4Ra monoclonal antibodies,which are currently available in Europe and North America,and are currently introduced in the rest of the world.[1]
