In this paper,distributed model predictive control(DMPC) for island DC micro-grids(MG) with wind/photovoltaic(PV)/battery power is proposed,which coordinates all distributed generations(DG) to stabilize the bus voltag...In this paper,distributed model predictive control(DMPC) for island DC micro-grids(MG) with wind/photovoltaic(PV)/battery power is proposed,which coordinates all distributed generations(DG) to stabilize the bus voltage together with the insurance of having computational efficiency under a real-time requirement.Based on the feedback of the bus voltage,the deviation of the current is dispatched to each DG according to cost over the prediction horizon.Moreover,to avoid the excessive fluctuation of the battery power,both the discharge-charge switching times and costs are considered in the model predictive control(MPC) optimization problems.A Lyapunov constraint with a time-varying steady-state is designed in each local MPC to guarantee the stabilization of the entire system.The voltage stabilization of the MG is achieved by this strategy with the cooperation of DGs.The numeric results of applying the proposed method to a MG of the Shanghai Power Supply Company shows the effectiveness of the distributed economic MPC.展开更多
A nonlinear semi-analytical scheme is proposed for investigating the finiteamplitude nonlinear sloshing in a horizontally baffled rectangular liquid container under the seismic excitation.The sub-domain method is deve...A nonlinear semi-analytical scheme is proposed for investigating the finiteamplitude nonlinear sloshing in a horizontally baffled rectangular liquid container under the seismic excitation.The sub-domain method is developed to analytically derive the modal behaviors of the baffled linear sloshing.The viscosity dissipation effects from the interior liquid and boundary layers are considered.With the introduction of the generalized time-dependent coordinates,the surface wave elevation and velocity potential are represented by a series of linear modal eigenfunctions.The infinite-dimensional modal system of the nonlinear sloshing is formulated based on the Bateman-Luke variational principle,which is further reduced to the finite-dimensional modal system by using the NarimanovMoiseev asymptotic ordering.The base force and overturning moment induced by the nonlinear sloshing are derived as the functions of the generalized time-dependent coordinates.The present results match well with the available analytical,numerical,and experimental results.The paper examines the surface wave elevation,base force,and overturning moment versus the baffle parameters and excitation amplitude in detail.展开更多
《医学微生物学》是医学院校的重点核心课程,实验教学是其重要的组成部分。但近年来,实验课课时被大幅度压缩,实验内容删减严重,教学效果不尽如人意。为解决实验课学时严重短缺、学习内容片段化、缺乏系统性的问题,智慧教学工具"...《医学微生物学》是医学院校的重点核心课程,实验教学是其重要的组成部分。但近年来,实验课课时被大幅度压缩,实验内容删减严重,教学效果不尽如人意。为解决实验课学时严重短缺、学习内容片段化、缺乏系统性的问题,智慧教学工具"雨课堂"被引入教学,通过课上及课后推送,将传统教学内容与MOOC(massive open online courses,慕课)、微课、手机微信融为一体,完善并丰富教学内容,有效提高教学效果。文章从实际应用角度出发,介绍"雨课堂"的使用方法和具体教学内容,并使用调查问卷分析教学效果。皆在与同行分享经验,为《医学微生物学》实验课教学改革提供有益的借鉴。展开更多
Peach(Prunus persica)is a typical climacteric fruit that produces ethylene rapidly during ripening,and its fruit softens quickly.Stony hard peach cultivars,however,do not produce large amounts of ethylene,and the frui...Peach(Prunus persica)is a typical climacteric fruit that produces ethylene rapidly during ripening,and its fruit softens quickly.Stony hard peach cultivars,however,do not produce large amounts of ethylene,and the fruit remains firm until fully ripe,thus differing from melting flesh peach cultivars.To identify the key proteins involved in peach fruit ripening,an antibody-based proteomic analysis was conducted.A mega-monoclonal antibody(mAb)library was generated and arrayed on a chip(mAbArray)at a high density,covering~4950 different proteins of peach.Through the screening of peach fruit proteins with the mAbArray chip,differentially expressed proteins recognized by 1587 mAbs were identified,and 33 corresponding antigens were ultimately identified by immunoprecipitation and mass spectrometry.These proteins included not only important enzymes involved in ethylene biosynthesis,such as ACO1,SAHH,SAMS,and MetE,but also novel factors such as NUDT2.Furthermore,protein–protein interaction analysis identified a metabolon containing SAHH and MetE.By combining the antibody-based proteomic data with the transcriptomic and metabolic data,a mathematical model of ethylene biosynthesis in peach was constructed.Simulation results showed that MetE is an important regulator during peach ripening,partially through interaction with SAHH.展开更多
The morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells.Here,we report a general approach for preparing Pt-M(M=Fe,Co and Ni)b...The morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells.Here,we report a general approach for preparing Pt-M(M=Fe,Co and Ni)bimetallic nano-branched structure(NBs)by a simple high temperature solution-phase synthesis.As-prepared Pt-M NBs show a polycrystalline structure and are rich in steps and kinks on the surface,which promote them favorable bifunctional catalytic properties in acidic electrolytes,specifically in terms of the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR).Specially,Pt-Co NBs/C catalyst shows 6.1 and 5.3 times higher in specific activity(SA)and mass activity(MA)for ORR than state-of-the-art commercial Pt/C catalysts,respectively.Moreover,it exhibits a loss of 4.0%in SA and 14.4%in MA after 10,000 cycles of accelerated durability tests(ADTs)compared with the initial activities.In addition,we also confirmed the superior MOR activity of Pt-Co NBs/C catalyst in acidic electrolytes.For Pt-M NBs with other alloying metals,the ORR and MOR activities are both higher than commercial catalysts and are in the sequence of Pt-Co/C>Pt-Fe/C>Pt-Ni/C>commercial Pt/C(or PtRu/C).The improved activities and durability can benefit from the morphological and compositional effects.This synthesis approach may be applied to develop bifunctional catalysts with enhanced ORR and MOR properties for future fuel cells designs.展开更多
基金supported by the National Key R&D Program of China (2018AAA0101701)the National Natural Science Foundation of China (62073220,61833012)。
文摘In this paper,distributed model predictive control(DMPC) for island DC micro-grids(MG) with wind/photovoltaic(PV)/battery power is proposed,which coordinates all distributed generations(DG) to stabilize the bus voltage together with the insurance of having computational efficiency under a real-time requirement.Based on the feedback of the bus voltage,the deviation of the current is dispatched to each DG according to cost over the prediction horizon.Moreover,to avoid the excessive fluctuation of the battery power,both the discharge-charge switching times and costs are considered in the model predictive control(MPC) optimization problems.A Lyapunov constraint with a time-varying steady-state is designed in each local MPC to guarantee the stabilization of the entire system.The voltage stabilization of the MG is achieved by this strategy with the cooperation of DGs.The numeric results of applying the proposed method to a MG of the Shanghai Power Supply Company shows the effectiveness of the distributed economic MPC.
基金Project supported by the National Natural Science Foundation of China(Nos.51978336 and11702117)。
文摘A nonlinear semi-analytical scheme is proposed for investigating the finiteamplitude nonlinear sloshing in a horizontally baffled rectangular liquid container under the seismic excitation.The sub-domain method is developed to analytically derive the modal behaviors of the baffled linear sloshing.The viscosity dissipation effects from the interior liquid and boundary layers are considered.With the introduction of the generalized time-dependent coordinates,the surface wave elevation and velocity potential are represented by a series of linear modal eigenfunctions.The infinite-dimensional modal system of the nonlinear sloshing is formulated based on the Bateman-Luke variational principle,which is further reduced to the finite-dimensional modal system by using the NarimanovMoiseev asymptotic ordering.The base force and overturning moment induced by the nonlinear sloshing are derived as the functions of the generalized time-dependent coordinates.The present results match well with the available analytical,numerical,and experimental results.The paper examines the surface wave elevation,base force,and overturning moment versus the baffle parameters and excitation amplitude in detail.
文摘《医学微生物学》是医学院校的重点核心课程,实验教学是其重要的组成部分。但近年来,实验课课时被大幅度压缩,实验内容删减严重,教学效果不尽如人意。为解决实验课学时严重短缺、学习内容片段化、缺乏系统性的问题,智慧教学工具"雨课堂"被引入教学,通过课上及课后推送,将传统教学内容与MOOC(massive open online courses,慕课)、微课、手机微信融为一体,完善并丰富教学内容,有效提高教学效果。文章从实际应用角度出发,介绍"雨课堂"的使用方法和具体教学内容,并使用调查问卷分析教学效果。皆在与同行分享经验,为《医学微生物学》实验课教学改革提供有益的借鉴。
基金supported by the National Key Research and Development Program[2018YFD1000200]the National Natural Science Foundation of China[31872085]the Agricultural Science and Technology Innovation Program(ASTIP)[CAAS-ASTIP-2020-ZFRI].
文摘Peach(Prunus persica)is a typical climacteric fruit that produces ethylene rapidly during ripening,and its fruit softens quickly.Stony hard peach cultivars,however,do not produce large amounts of ethylene,and the fruit remains firm until fully ripe,thus differing from melting flesh peach cultivars.To identify the key proteins involved in peach fruit ripening,an antibody-based proteomic analysis was conducted.A mega-monoclonal antibody(mAb)library was generated and arrayed on a chip(mAbArray)at a high density,covering~4950 different proteins of peach.Through the screening of peach fruit proteins with the mAbArray chip,differentially expressed proteins recognized by 1587 mAbs were identified,and 33 corresponding antigens were ultimately identified by immunoprecipitation and mass spectrometry.These proteins included not only important enzymes involved in ethylene biosynthesis,such as ACO1,SAHH,SAMS,and MetE,but also novel factors such as NUDT2.Furthermore,protein–protein interaction analysis identified a metabolon containing SAHH and MetE.By combining the antibody-based proteomic data with the transcriptomic and metabolic data,a mathematical model of ethylene biosynthesis in peach was constructed.Simulation results showed that MetE is an important regulator during peach ripening,partially through interaction with SAHH.
基金This work was supported by the National Natural Science Foundation of China(Nos.51571072 and 51871078)Heilongjiang Science Foundation(No.E2018028)the China Scholarship Council,and the NSF MRSEC Program(DMR-14-19807).
文摘The morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells.Here,we report a general approach for preparing Pt-M(M=Fe,Co and Ni)bimetallic nano-branched structure(NBs)by a simple high temperature solution-phase synthesis.As-prepared Pt-M NBs show a polycrystalline structure and are rich in steps and kinks on the surface,which promote them favorable bifunctional catalytic properties in acidic electrolytes,specifically in terms of the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR).Specially,Pt-Co NBs/C catalyst shows 6.1 and 5.3 times higher in specific activity(SA)and mass activity(MA)for ORR than state-of-the-art commercial Pt/C catalysts,respectively.Moreover,it exhibits a loss of 4.0%in SA and 14.4%in MA after 10,000 cycles of accelerated durability tests(ADTs)compared with the initial activities.In addition,we also confirmed the superior MOR activity of Pt-Co NBs/C catalyst in acidic electrolytes.For Pt-M NBs with other alloying metals,the ORR and MOR activities are both higher than commercial catalysts and are in the sequence of Pt-Co/C>Pt-Fe/C>Pt-Ni/C>commercial Pt/C(or PtRu/C).The improved activities and durability can benefit from the morphological and compositional effects.This synthesis approach may be applied to develop bifunctional catalysts with enhanced ORR and MOR properties for future fuel cells designs.
