The aim of this paper is to understand the common characteristics of the generalized flyby trajectory around natural elongated bodies. Such flyby trajectories provide a short-term mechanism to clear away vicinal objec...The aim of this paper is to understand the common characteristics of the generalized flyby trajectory around natural elongated bodies. Such flyby trajectories provide a short-term mechanism to clear away vicinal objects or temporally capture ejecta into circling orbits. The gravitational potential of elongated bodies is described by a unified approximate model, i.e., the rotating mass dipole which is two point masses connected with a constant massless rod The energy power is used to illustrate the flyby effect in terms of the instantaneous orbital energy. The essential of the single flyby trajectory is studied analytically, and the relationship between the flyby trajectory and its Jacobi integral is also illustrated. Sample trajectories are given to show the variational trend of the energy increment with respect to differen orbital periapsides. The distribution of natural ejecting orbits is presented by varying the parameters of the approximate model.展开更多
This paper studies the unsteady heat and mass natural convection in a highly porous medium bounded by an infinite vertical porous wall. The unsteady source of the problem arises from the transverse oscillations in suc...This paper studies the unsteady heat and mass natural convection in a highly porous medium bounded by an infinite vertical porous wall. The unsteady source of the problem arises from the transverse oscillations in suction velocity of fluids, The analytical results for the problem are obtained based on the method of small parameter, and show that the natural circulation in the porous medium is affected by this kind of oscillation.展开更多
Sialic acids as terminal entities of larger glycans linked to proteins and lipids are involved in multiple different pathological and physiological processes.Structural characterisation of sialoglycoconjugates is requ...Sialic acids as terminal entities of larger glycans linked to proteins and lipids are involved in multiple different pathological and physiological processes.Structural characterisation of sialoglycoconjugates is required to understand their biological function.However,a comprehensive sialylation analysis of sialoglycoconjugates has remained challenges.In this study,we employ a natural biomaterial,poplar catkin derived from white poplar tree（Populus tomentosa Carr.）,to develop a novel capturing microtip for selective and efficient enrichment of sialoglycopeptides,without losses of sialic acid residues and water molecules from sialoglycopeptides.Scanning electron microscopy and Fourier-transform infrared spectroscopy analysis,along with Maule and Wiesner staining assays,indicated that the main components on the outer layer of the poplar catkin are syringyl and guaiacyl lignins which play a key role in enriching sialoglycopeptides from complex peptide mixture.展开更多
Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter（NOM）and thousands that derive from anthropogenic contaminants.As complex as th...Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter（NOM）and thousands that derive from anthropogenic contaminants.As complex as these samples are,drinking water can be even more complex.Due to disinfectants that are used to treat drinking water（e.g.,chlorine,chloramines,展开更多
基金supported by the National Basic Research Program of China(973 Program),(Grant 2012CB720000)China Postdoctoral Science Foundation(Grant 2014M560076)Support from Shanghai Satellite Engineering Research Institute(Grant 13dz2260100)is also acknowledged
文摘The aim of this paper is to understand the common characteristics of the generalized flyby trajectory around natural elongated bodies. Such flyby trajectories provide a short-term mechanism to clear away vicinal objects or temporally capture ejecta into circling orbits. The gravitational potential of elongated bodies is described by a unified approximate model, i.e., the rotating mass dipole which is two point masses connected with a constant massless rod The energy power is used to illustrate the flyby effect in terms of the instantaneous orbital energy. The essential of the single flyby trajectory is studied analytically, and the relationship between the flyby trajectory and its Jacobi integral is also illustrated. Sample trajectories are given to show the variational trend of the energy increment with respect to differen orbital periapsides. The distribution of natural ejecting orbits is presented by varying the parameters of the approximate model.
文摘This paper studies the unsteady heat and mass natural convection in a highly porous medium bounded by an infinite vertical porous wall. The unsteady source of the problem arises from the transverse oscillations in suction velocity of fluids, The analytical results for the problem are obtained based on the method of small parameter, and show that the natural circulation in the porous medium is affected by this kind of oscillation.
基金supported by the National Natural Science Foundation of China(No.21575164)to Z.L
文摘Sialic acids as terminal entities of larger glycans linked to proteins and lipids are involved in multiple different pathological and physiological processes.Structural characterisation of sialoglycoconjugates is required to understand their biological function.However,a comprehensive sialylation analysis of sialoglycoconjugates has remained challenges.In this study,we employ a natural biomaterial,poplar catkin derived from white poplar tree（Populus tomentosa Carr.）,to develop a novel capturing microtip for selective and efficient enrichment of sialoglycopeptides,without losses of sialic acid residues and water molecules from sialoglycopeptides.Scanning electron microscopy and Fourier-transform infrared spectroscopy analysis,along with Maule and Wiesner staining assays,indicated that the main components on the outer layer of the poplar catkin are syringyl and guaiacyl lignins which play a key role in enriching sialoglycopeptides from complex peptide mixture.
文摘Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter（NOM）and thousands that derive from anthropogenic contaminants.As complex as these samples are,drinking water can be even more complex.Due to disinfectants that are used to treat drinking water（e.g.,chlorine,chloramines,
