Rip Van Winkle is one of the most enduring stories of Washington Irving. It is a fantasy tale about a man who somehow "stepped outside of the mainstream of life" (Chang Yao-xin, 1991: 62). Rip Van Winkle liv...Rip Van Winkle is one of the most enduring stories of Washington Irving. It is a fantasy tale about a man who somehow "stepped outside of the mainstream of life" (Chang Yao-xin, 1991: 62). Rip Van Winkle lived in a village near the Hudson River north of New York City. He was a simple, good-natured man; he was, moreover, a kind neighbor and an obedient hen-pecked husband. Yet Rip was lazy and this kept him in constant trouble with his wife. His two favorite past-times were sitting in front of the inn, chatting with his friends, and wandering through the mountains with his dog, Wolf. On one of these trips he met a strange dwarf who invited him to join him and other strange-looking dwarfs in a drinking party and a game called nine-pins, in a remote valley. Rip drank too much of beverage and fell asleep. When he woke up, he found that during just one night, twenty years had vanished and strangers were everywhere. His scolding wife had died, and his son, every bit his counterpart in appearance and personality had grown up to replace him. At last he was reunited with a married daughter and began to live a life the same as before.展开更多
A meshless numerical model is developed for analyzing transient heat conductions in three-dimensional （3D） axisymmetric continuously nonhomogeneous functionally graded materials （FGMs）. Axial symmetry of geometry ...A meshless numerical model is developed for analyzing transient heat conductions in three-dimensional （3D） axisymmetric continuously nonhomogeneous functionally graded materials （FGMs）. Axial symmetry of geometry and boundary conditions reduces the original 3D initial-boundary value problem into a two-dimensional （2D） problem. Local weak forms are derived for small polygonal sub-domains which surround nodal points distributed over the cross section. In order to simplify the treatment of the essential boundary conditions, spatial variations of the temperature and heat flux at discrete time instants are interpolated by the natural neighbor interpolation. Moreover, the using of three-node triangular finite element method （FEM） shape functions as test functions reduces the orders of integrands involved in domain integrals. The semi-discrete heat conduction equation is solved numerically with the traditional two-point difference technique in the time domain. Two numerical examples are investigated and excellent results are obtained, demonstrating the potential application of the proposed approach.展开更多
The state estimation of a maneuvering target,of which the trajectory shape is independent on dynamic characteristics,is studied.The conventional motion models in Cartesian coordinates imply that the trajectory of a ta...The state estimation of a maneuvering target,of which the trajectory shape is independent on dynamic characteristics,is studied.The conventional motion models in Cartesian coordinates imply that the trajectory of a target is completely determined by its dynamic characteristics.However,this is not true in the applications of road-target,sea-route-target or flight route-target tracking,where target trajectory shape is uncoupled with target velocity properties.In this paper,a new estimation algorithm based on separate modeling of target trajectory shape and dynamic characteristics is proposed.The trajectory of a target over a sliding window is described by a linear function of the arc length.To determine the unknown target trajectory,an augmented system is derived by denoting the unknown coefficients of the function as states in mileage coordinates.At every estimation cycle except the first one,the interaction(mixing)stage of the proposed algorithm starts from the latest estimated base state and a recalculated parameter vector,which is determined by the least squares(LS).Numerical experiments are conducted to assess the performance of the proposed algorithm.Simulation results show that the proposed algorithm can achieve better performance than the conventional coupled model-based algorithms in the presence of target maneuvers.展开更多
Synthetic biology is one of the rapid developing scientific fields in recent years. Through synthetic biology,we have a better understanding of the natural synthesis process of natural products, which provides a favor...Synthetic biology is one of the rapid developing scientific fields in recent years. Through synthetic biology,we have a better understanding of the natural synthesis process of natural products, which provides a favorable method to research the diversity of natural products, and also provides new tools for us to create new approach for producing natural products, we can synthesize compounds with different structures by artificial combination of different synthesis modules.展开更多
Poor bioavailability and undefined major/direct targets are two major obstacles for herbal medicines and natural products（NPs） to elucidate their precise mechanisms in vivo. Gut microbiota is an important bridge bet...Poor bioavailability and undefined major/direct targets are two major obstacles for herbal medicines and natural products（NPs） to elucidate their precise mechanisms in vivo. Gut microbiota is an important bridge between eukayotic body and environment, which can interact with a majority of medicines with poor bioavailability and mediate their in vivo pharmacological activities. There are two main modes through which gut microbiota may mediate the pharmacological effects of NPs. First, gut microbiota catabolizes the NPs in herbal medicines into secondary metabolites with higher bioavialability and/or higher activity, facilitating the NPs enter circulation and exert beneficial impact at the pathological spot. Second, herbal medicines and NPs can favorably shift the compositional structure of gut microbiota, thereby performing remote functions to diseased organs/tissues via the systemic impaction of gut microbiota. In this review, the potential pathways were summarized through which gut microbes facilitate the pharmacological functions of herbal medicines and NPs and highlight the significance of gut microbiota in clarifying the in vivo mechanisms of herbal medicines and NPs.展开更多
文摘Rip Van Winkle is one of the most enduring stories of Washington Irving. It is a fantasy tale about a man who somehow "stepped outside of the mainstream of life" (Chang Yao-xin, 1991: 62). Rip Van Winkle lived in a village near the Hudson River north of New York City. He was a simple, good-natured man; he was, moreover, a kind neighbor and an obedient hen-pecked husband. Yet Rip was lazy and this kept him in constant trouble with his wife. His two favorite past-times were sitting in front of the inn, chatting with his friends, and wandering through the mountains with his dog, Wolf. On one of these trips he met a strange dwarf who invited him to join him and other strange-looking dwarfs in a drinking party and a game called nine-pins, in a remote valley. Rip drank too much of beverage and fell asleep. When he woke up, he found that during just one night, twenty years had vanished and strangers were everywhere. His scolding wife had died, and his son, every bit his counterpart in appearance and personality had grown up to replace him. At last he was reunited with a married daughter and began to live a life the same as before.
基金Project supported by the National Natural Science Foundation of China(Grant No.11002054)the Foundation of Hunan Educational Committee(Grant No.12C0059).
文摘A meshless numerical model is developed for analyzing transient heat conductions in three-dimensional （3D） axisymmetric continuously nonhomogeneous functionally graded materials （FGMs）. Axial symmetry of geometry and boundary conditions reduces the original 3D initial-boundary value problem into a two-dimensional （2D） problem. Local weak forms are derived for small polygonal sub-domains which surround nodal points distributed over the cross section. In order to simplify the treatment of the essential boundary conditions, spatial variations of the temperature and heat flux at discrete time instants are interpolated by the natural neighbor interpolation. Moreover, the using of three-node triangular finite element method （FEM） shape functions as test functions reduces the orders of integrands involved in domain integrals. The semi-discrete heat conduction equation is solved numerically with the traditional two-point difference technique in the time domain. Two numerical examples are investigated and excellent results are obtained, demonstrating the potential application of the proposed approach.
基金supported by the National Natural Science Foundation of China(61671181).
文摘The state estimation of a maneuvering target,of which the trajectory shape is independent on dynamic characteristics,is studied.The conventional motion models in Cartesian coordinates imply that the trajectory of a target is completely determined by its dynamic characteristics.However,this is not true in the applications of road-target,sea-route-target or flight route-target tracking,where target trajectory shape is uncoupled with target velocity properties.In this paper,a new estimation algorithm based on separate modeling of target trajectory shape and dynamic characteristics is proposed.The trajectory of a target over a sliding window is described by a linear function of the arc length.To determine the unknown target trajectory,an augmented system is derived by denoting the unknown coefficients of the function as states in mileage coordinates.At every estimation cycle except the first one,the interaction(mixing)stage of the proposed algorithm starts from the latest estimated base state and a recalculated parameter vector,which is determined by the least squares(LS).Numerical experiments are conducted to assess the performance of the proposed algorithm.Simulation results show that the proposed algorithm can achieve better performance than the conventional coupled model-based algorithms in the presence of target maneuvers.
文摘Synthetic biology is one of the rapid developing scientific fields in recent years. Through synthetic biology,we have a better understanding of the natural synthesis process of natural products, which provides a favorable method to research the diversity of natural products, and also provides new tools for us to create new approach for producing natural products, we can synthesize compounds with different structures by artificial combination of different synthesis modules.
基金National Natural Science Foundation of China(No.81673663)CAMS Innovation Fund for Medical Sciences(CIFMS 2016-I2M-3-015)
文摘Poor bioavailability and undefined major/direct targets are two major obstacles for herbal medicines and natural products（NPs） to elucidate their precise mechanisms in vivo. Gut microbiota is an important bridge between eukayotic body and environment, which can interact with a majority of medicines with poor bioavailability and mediate their in vivo pharmacological activities. There are two main modes through which gut microbiota may mediate the pharmacological effects of NPs. First, gut microbiota catabolizes the NPs in herbal medicines into secondary metabolites with higher bioavialability and/or higher activity, facilitating the NPs enter circulation and exert beneficial impact at the pathological spot. Second, herbal medicines and NPs can favorably shift the compositional structure of gut microbiota, thereby performing remote functions to diseased organs/tissues via the systemic impaction of gut microbiota. In this review, the potential pathways were summarized through which gut microbes facilitate the pharmacological functions of herbal medicines and NPs and highlight the significance of gut microbiota in clarifying the in vivo mechanisms of herbal medicines and NPs.
