In this paper, we propose a multistage Volterra filter and show it is equivalent to the partially decoupled Volterra per as formulated in [1]. Using this approach. we may readily derive a partially decoupled parallel ...In this paper, we propose a multistage Volterra filter and show it is equivalent to the partially decoupled Volterra per as formulated in [1]. Using this approach. we may readily derive a partially decoupled parallel algorithm for adaptation of filter's coefficients and upper bounds for each of the step sizes. The approach greatly simplifies the derivation given in [1].展开更多
Aimed at the problems of design difficulty and weak kinematic performance caused by spherical joint,a novel PRC+PRCR+RR humanoid ankle joint based on the partially decoupled spherical parallel mechanism is proposed.Ac...Aimed at the problems of design difficulty and weak kinematic performance caused by spherical joint,a novel PRC+PRCR+RR humanoid ankle joint based on the partially decoupled spherical parallel mechanism is proposed.According to screw theory,the degree of freedom and decoupling characteristics of this mechanism are analyzed.Based on Klein formula and virtual work principle,the kinematic expressions of each link and dynamic model are established.The correctness of the dynamic model is verified by combining the virtual prototype software and the ankle pose function obtained by gait planning and Fourier fitting.The workspace of this mechanism is mapped into a two-dimensional polar coordinate system with the azimuth and elevation angles of the spherical coordinate system as parameters.The motion/force transmission index and constraint index of this mechanism are evaluated and expressed in the workspace,showing this mechanism with excellent kinematic characteristics.展开更多
Voluminous Silurian–Devonian granitoids intruded a greywacke-dominated Ordovician accretionary wedge in the Chinese Altai. These granitoids are characterized by significant Nd-Hf isotopic decoupling, the underlying m...Voluminous Silurian–Devonian granitoids intruded a greywacke-dominated Ordovician accretionary wedge in the Chinese Altai. These granitoids are characterized by significant Nd-Hf isotopic decoupling, the underlying mechanism of which, so far, has been poorly understood. This issue is addressed in this study by the integration of our new and regional published geological and geochemical data. Geological studies indicated a close spatial relationship between the regional anatexis of the Ordovician wedge and the formation of the granitoids, which is characterized by a gradual textural evolution from the partial molten Ordovician wedge sedimentary rocks(the Habahe Group) to the granitoid bodies. Compositionally, these granitoids and the Ordovician Habahe Group rocks displayed close geochemical similarities, in the form of arclike trace elemental signatures as well as comparable Nd isotopic characteristics. Combined with regional available data, we suggest that the Silurian–Devonian granitoids originated from the immature and chemically primitive Habahe Group rocks. Since Nd and Hf isotopic data for the Habahe Group rocks show significant Nd-Hf isotopic decoupling, we propose that the Silurian–Devonian granitoids inherited the Nd and Hf isotopic signatures from their sources, i.e., the Habahe Group rocks. In other words, the Nd-Hf decoupling in the Habahe Group rocks is the primary causative factor leading to the prevailing Nd-Hf isotopic decoupling of the Silurian–Devonian granitoids in the Chinese Altai.展开更多
文摘In this paper, we propose a multistage Volterra filter and show it is equivalent to the partially decoupled Volterra per as formulated in [1]. Using this approach. we may readily derive a partially decoupled parallel algorithm for adaptation of filter's coefficients and upper bounds for each of the step sizes. The approach greatly simplifies the derivation given in [1].
基金the Zhejiang Province Foundation for Distinguished Young Scholars of China(No.LR18E050003)the National Natural Science Foundation of China(Nos.51975523 and 51475424)。
文摘Aimed at the problems of design difficulty and weak kinematic performance caused by spherical joint,a novel PRC+PRCR+RR humanoid ankle joint based on the partially decoupled spherical parallel mechanism is proposed.According to screw theory,the degree of freedom and decoupling characteristics of this mechanism are analyzed.Based on Klein formula and virtual work principle,the kinematic expressions of each link and dynamic model are established.The correctness of the dynamic model is verified by combining the virtual prototype software and the ankle pose function obtained by gait planning and Fourier fitting.The workspace of this mechanism is mapped into a two-dimensional polar coordinate system with the azimuth and elevation angles of the spherical coordinate system as parameters.The motion/force transmission index and constraint index of this mechanism are evaluated and expressed in the workspace,showing this mechanism with excellent kinematic characteristics.
基金supported by the National Key R&D Program of China(No.2017YFC0601205)the Strategic Priority Research Program(B)of the CAS(No.XDB18020203)+4 种基金the NSF China(No.41672056)the Guangdong Special Support ProgramGIG-CAS 135 Project(No.135TP201601)A 100 Talents Program of the CAS to Yingde Jianga China Postdoctoral Science Foundation to Yu Yang(No.2018M633172)
文摘Voluminous Silurian–Devonian granitoids intruded a greywacke-dominated Ordovician accretionary wedge in the Chinese Altai. These granitoids are characterized by significant Nd-Hf isotopic decoupling, the underlying mechanism of which, so far, has been poorly understood. This issue is addressed in this study by the integration of our new and regional published geological and geochemical data. Geological studies indicated a close spatial relationship between the regional anatexis of the Ordovician wedge and the formation of the granitoids, which is characterized by a gradual textural evolution from the partial molten Ordovician wedge sedimentary rocks(the Habahe Group) to the granitoid bodies. Compositionally, these granitoids and the Ordovician Habahe Group rocks displayed close geochemical similarities, in the form of arclike trace elemental signatures as well as comparable Nd isotopic characteristics. Combined with regional available data, we suggest that the Silurian–Devonian granitoids originated from the immature and chemically primitive Habahe Group rocks. Since Nd and Hf isotopic data for the Habahe Group rocks show significant Nd-Hf isotopic decoupling, we propose that the Silurian–Devonian granitoids inherited the Nd and Hf isotopic signatures from their sources, i.e., the Habahe Group rocks. In other words, the Nd-Hf decoupling in the Habahe Group rocks is the primary causative factor leading to the prevailing Nd-Hf isotopic decoupling of the Silurian–Devonian granitoids in the Chinese Altai.
