On the problem of competing channel structure, we present asymmetry competing channel structure models under bargaining power, analyze the evolving process of channel structure under different bargaining power and pro...On the problem of competing channel structure, we present asymmetry competing channel structure models under bargaining power, analyze the evolving process of channel structure under different bargaining power and product nature, find different bargaining power and product nature important role for channel structure, and also present equilibrium result. Furthermore, the academic proof for channel structure choice is presented.展开更多
The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under differe...The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under different conditions. We find that like product difference, cost difference have important influence on the choice of channel structure. This paper has improved the present result and provided proof for the choice of channel structure under different environments.展开更多
From the bargaining process, competing channel structure models are presented. The evolving process of channel structure under different bargaining power is analyzed The important role of different bargaining power is...From the bargaining process, competing channel structure models are presented. The evolving process of channel structure under different bargaining power is analyzed The important role of different bargaining power is discussed and the equilibrium result is found. Also the theoretical evidences for competing channel structure choice are given.展开更多
Printed circuit heat exchanger(PCHE)has been widely used in supercritical carbon dioxide(S-CO_(2))power systems because of its high heat transfer efficiency and good compactness.However,due to the large variety of PCH...Printed circuit heat exchanger(PCHE)has been widely used in supercritical carbon dioxide(S-CO_(2))power systems because of its high heat transfer efficiency and good compactness.However,due to the large variety of PCHE configurations,channel selection in practical applications lacks a basis.Therefore,this paper discussed the heat transfer and friction characteristics and the synergy of three fields in the channel under the guidance of the field synergy principle for four typical PCHE channels.Additionally,the comprehensive performance of four channels was compared.Finally,the heat transfer and friction factor correlations for S-CO_(2)in four channels were established.The findings demonstrate that the synergy of velocity and pressure fields of the straight channel PCHE is better(β≈180°),so its resistance loss is relatively small.The zigzag and sinusoidal wavy channels and the airfoil fins can reduce the angle a between the temperature gradient and velocity,thus enhancing the heat transfer.The sinusoidal wavy channel can reduce flow resistance compared to the zigzag channel due to the rounded corners.The streamlined airfoil structure can guide the flow and reduce backflow,thus reducing resistance losses.In the range of Re studied in this paper,the maximum error of the proposed heat transfer and friction factor correlations of PCHE is 7.0%,which shows good fitting accuracy.The research in this paper can provide a reference for the selection and design of PCHE with different channel configurations.展开更多
The combination of both 4,4′-bipyridine(4,4′-bipy) and dihydrogen phosphate anion ligands with copper(Ⅱ) results in the formation of a novel layered compound Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2. The crystal structu...The combination of both 4,4′-bipyridine(4,4′-bipy) and dihydrogen phosphate anion ligands with copper(Ⅱ) results in the formation of a novel layered compound Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2. The crystal structure comprises discrete neutral Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2 units. The copper atom,located on the crystallographic twofold axis,is coordinated with two nitrogen atoms of terminal 4,4′-bipy ligands and two water molecules at the equatorial positions,and two dihydrogen phosphate oxygen atoms at the axial positions,forming an elongated octahedron. The complex is a two-dimensional distorted rhomboidal network possessing two kinds of rhomboids with dimensions of ca . 1.6792 nm×0.3203 nm and 1.2778 nm×0.3198 nm,respectively. The two-dimensional networks are stacked parallelly on each other along c -axis to give an extended three-dimensional channel network with an interlayer distance of ca . 0.5030 nm. Crystal data: triclinic,space group P -_1,a =1.0253(2) nm,b =1.4501(3) nm,c =0.79715(16) nm, α =97.91(3)°,β = 90.99(3)° ,γ =85.54(3)°,V =1.1703(4) nm 3,Z =2,R =0.0892,wR =0.2451.展开更多
The ground-state energy level (GEL) and electron distribution of GaAs pseudomorphic high-electron-mobility transistors (PHEMTs) are analyzed by a self-consistent solution to the Schrodinger-Poisson equations. The ...The ground-state energy level (GEL) and electron distribution of GaAs pseudomorphic high-electron-mobility transistors (PHEMTs) are analyzed by a self-consistent solution to the Schrodinger-Poisson equations. The indium composition and thickness of the InGaAs channel are optimized according to the GEL position. The GEL position is not in direct proportion to 1/d^2 (d is the channel thickness) by considering the influence of electron distribution in the InGaAs channel. Indium composition 0.22 and channel thickness 9 nm are obtained by considering the mismatch between InGaAs and AlGaAs. Several PHEMT samples are grown according to the theoretical results and mobility 6300 cm^2 /V.s is achieved.展开更多
Molecular dynamics method is used to study the conformation behavior of a semi-flexible polymer chain confined in a cylinder channel.A novel helix-like structure is found to form during the simulation.Moreover,the det...Molecular dynamics method is used to study the conformation behavior of a semi-flexible polymer chain confined in a cylinder channel.A novel helix-like structure is found to form during the simulation.Moreover,the detailed characteristic parameters and formation probability of these helix-like structures under moderate conditions are investigated.We find that the structure is not a perfect helix,but a bundle of elliptical turns.In addition,we conduct a statistical analysis for the chain monomer distribution along the radial direction.This research contributes to our understanding of the microscopic conformation of polymer chains in confined environments filled with a solvent.展开更多
Voltage-gated sodium(Nav)channels are critical players in the generation and propagation of action potentials by triggering membrane depolarization.Mutations in Nav channels are associated with a variety of channelopa...Voltage-gated sodium(Nav)channels are critical players in the generation and propagation of action potentials by triggering membrane depolarization.Mutations in Nav channels are associated with a variety of channelopathies,which makes them relevant targets for pharmaceutical intervention.Sofar,the cryoelectron microscopic structure of the human Nav 1.2,Nav 1.4,and Nav 1.7 has been reported,which sheds light on the molecular basis of functional mechanism of Nav channels and provides a path toward structure-based drug discovery.In this review,we focus on the recent advances in the structure,molecular mechanism and modulation of Nav channels,and state updated sodium channel blockers for the treatment of pathophysiology disorders and briefly discuss where the blockers may be developed in the future.展开更多
The organized alignment of cells in various tissues plays a significant role in the maintenance of specific functions.To induce such an alignment,ideal scaffolds should simulate the characteristics and morphologies of...The organized alignment of cells in various tissues plays a significant role in the maintenance of specific functions.To induce such an alignment,ideal scaffolds should simulate the characteristics and morphologies of natural tissues.Aligned structures that guide cell orientation are used to facilitate tissue regeneration and repair.We here review how various aligned structures are fabricated,including aligned electrospun nanofibers,aligned porous or channeled structures,micropatterns and combinations thereof,and their application in nerve,skeletal muscle,tendon,and tubular dentin regeneration.The future use of aligned structures in tissue engineering is also discussed.展开更多
In a multichannel supply chain comprising of dual-channel retailers with both physical and online channels as well as single-channel e-tailers with online channels,a multichannel demand model for e-commerce is constru...In a multichannel supply chain comprising of dual-channel retailers with both physical and online channels as well as single-channel e-tailers with online channels,a multichannel demand model for e-commerce is constructed based on customer channel preferences,and a Stackerberg game model with price competition dominated by dual-channel retailers and single-channel e-tailers as well as a Bertrand game model with equal rights are established to analyze the impact of different channel rights structures on the price,demand,and profit of the two retailers.The results show that the single-channel e-tailer under the dual-channel retailer-dominated game has the highest profit,and the dual-channel retailer xmder the single-channel e-tailer-dominated game has the highest profit;thus,both retailers should accept the other's dominant channel rights for profit maximization.展开更多
For realizing diffused anode attachment in pure nitrogen arcs, a special arc plasma generator was designed and combined with suitable working parameters such as gas flow rate and arc current. The anode has a flow-rest...For realizing diffused anode attachment in pure nitrogen arcs, a special arc plasma generator was designed and combined with suitable working parameters such as gas flow rate and arc current. The anode has a flow-restrictor channel of 2.8 mm diameter and downstream expansion half-angle of 8°, with the purpose of creating a dispersed nitrogen-arc column by strong gasdynamic expansion effect. Results show that, when thermal blocking condition existed in the flow restrictor and the cathode cavity pressure was higher than that in the exit chamber by at least 9 kPa, the action due to gasdynamic expansion could be much stronger than the self-magnetic contraction effect of the arc and the nitrogen arc column could be effectively dispersed to form a sufficiently diffused attachment on the water-cooled anode surface.展开更多
In order to secure the massive heterogeneous medical data for the complex scenarios and improve the information sharing efficiency in healthcare system,a distributed medical data ledger model(DMDL)is proposed in this ...In order to secure the massive heterogeneous medical data for the complex scenarios and improve the information sharing efficiency in healthcare system,a distributed medical data ledger model(DMDL)is proposed in this paper.This DMDL model has adopted the blockchain technology including the function decoupling,the distributed consensus,smart contract as well as multi-channel communication structure of consortium blockchain.The DMDL model not only has high adaptability,but also meets the requirements of the medical treatment processes which generally involve multientities,highly private information and secure transaction.The steps for processing the medical data are also introduced.Additionally,the methods for the definition and application of the DMDL model are presented for three specific medical scenarios,i.e.,the management of the heterogeneous data,copyright protection for medical data and the secure utilization of sensitive data.The advantage of the proposed DMDL model is demonstrated by comparing with the models which are being currently adopted in healthcare system.展开更多
Wall-bounded turbulent flow involves the development of multi-scale turbulent eddies, as well as a sharply varying boundary layer. Its theoretical descriptions are yet phenomenological. We present here a new framework...Wall-bounded turbulent flow involves the development of multi-scale turbulent eddies, as well as a sharply varying boundary layer. Its theoretical descriptions are yet phenomenological. We present here a new framework called structural ensemble dynamics (SED), which aims at using systematically all relevant statistical properties of turbulent structures for a quantitative description of ensemble means. A new set of closure equations based on the SED approach for a turbulent channel flow is presented. SED order functions are defined, and numerically determined from data of direct numerical simulations (DNS). Computational results show that the new closure model reproduces accurately the solution of the original Navier-Stokes simulation, including the mean velocity profile, the kinetic energy of the streamwise velocity component, and every term in the energy budget equation. It is suggested that the SED-based studies of turbulent structure builds a bridge between the studies of physical mechanisms of turbulence and the development of accurate model equations for engineering predictions.展开更多
The family of voltage-gated (Shaker-like) potassium channels in plants includes both inward-rectifying (Kin) channels that allow plant cells to accumulate K+ and outward-rectifying (Kout) channels that mediate ...The family of voltage-gated (Shaker-like) potassium channels in plants includes both inward-rectifying (Kin) channels that allow plant cells to accumulate K+ and outward-rectifying (Kout) channels that mediate K+ efflux. Despite their dose structural similarities, Kin and Kout channels differ in their gating sensitivity towards voltage and the extracellular K+ concentration. We have carried out a systematic program of domain swapping between the Kout channel SKOR and the Kin channel KAT1 to examine the impacts on gating of the pore regions, the S4, S5, and the S6 helices. We found that, in particular, the N-terminal part of the S5 played a critical role in KAT1 and SKOR gating. Our findings were supported by molecular dynamics of KAT1 and SKOR homology models. In silico analysis revealed that during channel opening and closing, displacement of certain residues, especially in the S5 and S6 segments, is more pronounced in KAT1 than in SKOR. From our analysis of the S4-S6 region, we conclude that gating (and K+-sensing in SKOR) depend on a number of structural elements that are dispersed over this -145-residue sequence and that these place additional constraints on configurational rearrangement of the channels during gating.展开更多
Subject Code:C05 With the support by the National Natural Science Foundation of China,the collaborative research team led by Prof.Chen Lei(陈雷)at the State Key Laboratory of Membrane Biology,Institute of Molecular Me...Subject Code:C05 With the support by the National Natural Science Foundation of China,the collaborative research team led by Prof.Chen Lei(陈雷)at the State Key Laboratory of Membrane Biology,Institute of Molecular Medicine,Peking-Tsinghua Center for Life Sciences,Beijing Key Laboratory of Cardiometabolic展开更多
This paper develops manufacturer's channel selection models considering carbon emission reduction and remanufacturing. The models are based on the cap-and-trade system and consumer's preference for low-carbon produc...This paper develops manufacturer's channel selection models considering carbon emission reduction and remanufacturing. The models are based on the cap-and-trade system and consumer's preference for low-carbon product. We study the strategies of pricing and carbon emission reduction under three channel structures: pure online channel, pure offiine channel and dual channel. The results show that a higher recovery rate of remanufacturing can bring a higher reduction in carbon emission level and a lower price for consumers in the three channel structures. Compared to the pure online channel and pure offiine channel, the dual channel is the optimal selection for a for-profit manufacturer However, for a retailer, the pure offiine channel is more profitable than the dual channel. From the perspective of carbon emission reduction, the dual channel and the pure online channel generate the same effect; the pure offiine channel makes the highest reduction in carbon emission when consumers' acceptance for online channel is low. More managerial insights are provided in sensitivity analysis.展开更多
The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a...The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a generalized channel structures strategy with optimized in situ polymerization technology in their recent study.The resultant FLBs can be woven into different-sized powering textiles,providing a high energy density output of 128 Wh kg^(-1) and simultaneously demonstrating good durability even under harsh conditions.Such a promising strategy expands the horizon in developing FLB with particular polymer gel electrolytes,and significantly ever-deepening understanding of the scaled wearable energy textile system toward a sustainable future.展开更多
The spatial relationship between the energy dissipation slabs and the vortex tubes is investigated based on the direct numerical simulation(DNS) of the channel flow. The spatial distance between these two structures...The spatial relationship between the energy dissipation slabs and the vortex tubes is investigated based on the direct numerical simulation(DNS) of the channel flow. The spatial distance between these two structures is found to be slightly greater than the vortex radius. Comparison of the core areas of the vortex tubes and the dissipation slabs gives a mean ratio of 0.16 for the mean swirling strength and that of 2.89 for the mean dissipation rate. These results verify that in the channel flow the slabs of intense dissipation and the vortex tubes do not coincide in space. Rather they appear in pairs offset with a mean separation of approximately 10η.展开更多
The impressive development of China's economy over the past few decades has enabled non-financial firms to adopt financial investment in exchange for enhanced financing behavior and short-term profit(shareholder v...The impressive development of China's economy over the past few decades has enabled non-financial firms to adopt financial investment in exchange for enhanced financing behavior and short-term profit(shareholder value)maximization,while the persistence of fixed investment leading to dramatic capital accumulation has spurred the nation's rapid economic growth.The existing literature has extensive discussions on the crowd-out effect of financial activities on non-financial firms'fixed investment but overlooks to what extent and under what forces financial activities potentially benefit real investment.This paper investigates whether profits from financial activities have an inverted U-shape relationship with firms'fixed investment.In particular,we aim to identify if the benefit of financial profit on fixed investment is through the financial constraint channel and/or ownership structure channel for Chinese-listed firms from 2003 to 2018.We present robust evidence to support the inverted U-shape relationship between financial profit and fixed investment for the whole sample of firms as well as the split samples of firms(SOEs and non-SOEs).Moreover,among all channels including cash flow,debt financing,managerial shareholding,ownership concentration,and state ownership,this research documents that financial profit mainly benefits firms by reducing debt burden.Firms with concentrated ownership and strong state shareholding are also more likely to crowd-out real investment or potentially alleviate overinvestment.Nevertheless,non-SOEs are more prone to benefit from financial profits by reducing the debt overhang problem than SOEs,whereas ownership concentration for SOEs non-increments the crowd-out effect.展开更多
文摘On the problem of competing channel structure, we present asymmetry competing channel structure models under bargaining power, analyze the evolving process of channel structure under different bargaining power and product nature, find different bargaining power and product nature important role for channel structure, and also present equilibrium result. Furthermore, the academic proof for channel structure choice is presented.
基金Supported by the National Preeminence Youth Foundation of China(No.79275002)
文摘The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under different conditions. We find that like product difference, cost difference have important influence on the choice of channel structure. This paper has improved the present result and provided proof for the choice of channel structure under different environments.
文摘From the bargaining process, competing channel structure models are presented. The evolving process of channel structure under different bargaining power is analyzed The important role of different bargaining power is discussed and the equilibrium result is found. Also the theoretical evidences for competing channel structure choice are given.
基金supported by the National Key R&D Program of China(No.2022YFB3304001)the Key R&D Special Program of Shaanxi province(No.2022GXLH-01-04)。
文摘Printed circuit heat exchanger(PCHE)has been widely used in supercritical carbon dioxide(S-CO_(2))power systems because of its high heat transfer efficiency and good compactness.However,due to the large variety of PCHE configurations,channel selection in practical applications lacks a basis.Therefore,this paper discussed the heat transfer and friction characteristics and the synergy of three fields in the channel under the guidance of the field synergy principle for four typical PCHE channels.Additionally,the comprehensive performance of four channels was compared.Finally,the heat transfer and friction factor correlations for S-CO_(2)in four channels were established.The findings demonstrate that the synergy of velocity and pressure fields of the straight channel PCHE is better(β≈180°),so its resistance loss is relatively small.The zigzag and sinusoidal wavy channels and the airfoil fins can reduce the angle a between the temperature gradient and velocity,thus enhancing the heat transfer.The sinusoidal wavy channel can reduce flow resistance compared to the zigzag channel due to the rounded corners.The streamlined airfoil structure can guide the flow and reduce backflow,thus reducing resistance losses.In the range of Re studied in this paper,the maximum error of the proposed heat transfer and friction factor correlations of PCHE is 7.0%,which shows good fitting accuracy.The research in this paper can provide a reference for the selection and design of PCHE with different channel configurations.
文摘The combination of both 4,4′-bipyridine(4,4′-bipy) and dihydrogen phosphate anion ligands with copper(Ⅱ) results in the formation of a novel layered compound Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2. The crystal structure comprises discrete neutral Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2 units. The copper atom,located on the crystallographic twofold axis,is coordinated with two nitrogen atoms of terminal 4,4′-bipy ligands and two water molecules at the equatorial positions,and two dihydrogen phosphate oxygen atoms at the axial positions,forming an elongated octahedron. The complex is a two-dimensional distorted rhomboidal network possessing two kinds of rhomboids with dimensions of ca . 1.6792 nm×0.3203 nm and 1.2778 nm×0.3198 nm,respectively. The two-dimensional networks are stacked parallelly on each other along c -axis to give an extended three-dimensional channel network with an interlayer distance of ca . 0.5030 nm. Crystal data: triclinic,space group P -_1,a =1.0253(2) nm,b =1.4501(3) nm,c =0.79715(16) nm, α =97.91(3)°,β = 90.99(3)° ,γ =85.54(3)°,V =1.1703(4) nm 3,Z =2,R =0.0892,wR =0.2451.
文摘The ground-state energy level (GEL) and electron distribution of GaAs pseudomorphic high-electron-mobility transistors (PHEMTs) are analyzed by a self-consistent solution to the Schrodinger-Poisson equations. The indium composition and thickness of the InGaAs channel are optimized according to the GEL position. The GEL position is not in direct proportion to 1/d^2 (d is the channel thickness) by considering the influence of electron distribution in the InGaAs channel. Indium composition 0.22 and channel thickness 9 nm are obtained by considering the mismatch between InGaAs and AlGaAs. Several PHEMT samples are grown according to the theoretical results and mobility 6300 cm^2 /V.s is achieved.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504033 and 11404290)the General Research Fund of Hong Kong Research Council of China(Grant No.15301014)
文摘Molecular dynamics method is used to study the conformation behavior of a semi-flexible polymer chain confined in a cylinder channel.A novel helix-like structure is found to form during the simulation.Moreover,the detailed characteristic parameters and formation probability of these helix-like structures under moderate conditions are investigated.We find that the structure is not a perfect helix,but a bundle of elliptical turns.In addition,we conduct a statistical analysis for the chain monomer distribution along the radial direction.This research contributes to our understanding of the microscopic conformation of polymer chains in confined environments filled with a solvent.
基金the National Natural Science Foundation of China(Nos.81473254,81773637,81773594,U1703111)the Fundamental Research Fund for the Central Universities(No.2017KFYXJJ151).
文摘Voltage-gated sodium(Nav)channels are critical players in the generation and propagation of action potentials by triggering membrane depolarization.Mutations in Nav channels are associated with a variety of channelopathies,which makes them relevant targets for pharmaceutical intervention.Sofar,the cryoelectron microscopic structure of the human Nav 1.2,Nav 1.4,and Nav 1.7 has been reported,which sheds light on the molecular basis of functional mechanism of Nav channels and provides a path toward structure-based drug discovery.In this review,we focus on the recent advances in the structure,molecular mechanism and modulation of Nav channels,and state updated sodium channel blockers for the treatment of pathophysiology disorders and briefly discuss where the blockers may be developed in the future.
基金This work was financially supported by the National Key Research and Development Program of China(2018YFA0703000)the NationalNatural Science Foundation of China(81670972,31872752)+1 种基金Key Research and Development Program of Zhejiang,China(2017C01054,2018C03062,2017C01063)Postdoctoral Science Foundation of China(2020TQ0257,2020M681896).
文摘The organized alignment of cells in various tissues plays a significant role in the maintenance of specific functions.To induce such an alignment,ideal scaffolds should simulate the characteristics and morphologies of natural tissues.Aligned structures that guide cell orientation are used to facilitate tissue regeneration and repair.We here review how various aligned structures are fabricated,including aligned electrospun nanofibers,aligned porous or channeled structures,micropatterns and combinations thereof,and their application in nerve,skeletal muscle,tendon,and tubular dentin regeneration.The future use of aligned structures in tissue engineering is also discussed.
文摘In a multichannel supply chain comprising of dual-channel retailers with both physical and online channels as well as single-channel e-tailers with online channels,a multichannel demand model for e-commerce is constructed based on customer channel preferences,and a Stackerberg game model with price competition dominated by dual-channel retailers and single-channel e-tailers as well as a Bertrand game model with equal rights are established to analyze the impact of different channel rights structures on the price,demand,and profit of the two retailers.The results show that the single-channel e-tailer under the dual-channel retailer-dominated game has the highest profit,and the dual-channel retailer xmder the single-channel e-tailer-dominated game has the highest profit;thus,both retailers should accept the other's dominant channel rights for profit maximization.
基金supported by the National Natural Science Foundation of China (11575273)
文摘For realizing diffused anode attachment in pure nitrogen arcs, a special arc plasma generator was designed and combined with suitable working parameters such as gas flow rate and arc current. The anode has a flow-restrictor channel of 2.8 mm diameter and downstream expansion half-angle of 8°, with the purpose of creating a dispersed nitrogen-arc column by strong gasdynamic expansion effect. Results show that, when thermal blocking condition existed in the flow restrictor and the cathode cavity pressure was higher than that in the exit chamber by at least 9 kPa, the action due to gasdynamic expansion could be much stronger than the self-magnetic contraction effect of the arc and the nitrogen arc column could be effectively dispersed to form a sufficiently diffused attachment on the water-cooled anode surface.
文摘In order to secure the massive heterogeneous medical data for the complex scenarios and improve the information sharing efficiency in healthcare system,a distributed medical data ledger model(DMDL)is proposed in this paper.This DMDL model has adopted the blockchain technology including the function decoupling,the distributed consensus,smart contract as well as multi-channel communication structure of consortium blockchain.The DMDL model not only has high adaptability,but also meets the requirements of the medical treatment processes which generally involve multientities,highly private information and secure transaction.The steps for processing the medical data are also introduced.Additionally,the methods for the definition and application of the DMDL model are presented for three specific medical scenarios,i.e.,the management of the heterogeneous data,copyright protection for medical data and the secure utilization of sensitive data.The advantage of the proposed DMDL model is demonstrated by comparing with the models which are being currently adopted in healthcare system.
基金supported by the National Natural Science Foundation of China (90716008)the MOST under 973 project (2009CB724100)
文摘Wall-bounded turbulent flow involves the development of multi-scale turbulent eddies, as well as a sharply varying boundary layer. Its theoretical descriptions are yet phenomenological. We present here a new framework called structural ensemble dynamics (SED), which aims at using systematically all relevant statistical properties of turbulent structures for a quantitative description of ensemble means. A new set of closure equations based on the SED approach for a turbulent channel flow is presented. SED order functions are defined, and numerically determined from data of direct numerical simulations (DNS). Computational results show that the new closure model reproduces accurately the solution of the original Navier-Stokes simulation, including the mean velocity profile, the kinetic energy of the streamwise velocity component, and every term in the energy budget equation. It is suggested that the SED-based studies of turbulent structure builds a bridge between the studies of physical mechanisms of turbulence and the development of accurate model equations for engineering predictions.
文摘The family of voltage-gated (Shaker-like) potassium channels in plants includes both inward-rectifying (Kin) channels that allow plant cells to accumulate K+ and outward-rectifying (Kout) channels that mediate K+ efflux. Despite their dose structural similarities, Kin and Kout channels differ in their gating sensitivity towards voltage and the extracellular K+ concentration. We have carried out a systematic program of domain swapping between the Kout channel SKOR and the Kin channel KAT1 to examine the impacts on gating of the pore regions, the S4, S5, and the S6 helices. We found that, in particular, the N-terminal part of the S5 played a critical role in KAT1 and SKOR gating. Our findings were supported by molecular dynamics of KAT1 and SKOR homology models. In silico analysis revealed that during channel opening and closing, displacement of certain residues, especially in the S5 and S6 segments, is more pronounced in KAT1 than in SKOR. From our analysis of the S4-S6 region, we conclude that gating (and K+-sensing in SKOR) depend on a number of structural elements that are dispersed over this -145-residue sequence and that these place additional constraints on configurational rearrangement of the channels during gating.
文摘Subject Code:C05 With the support by the National Natural Science Foundation of China,the collaborative research team led by Prof.Chen Lei(陈雷)at the State Key Laboratory of Membrane Biology,Institute of Molecular Medicine,Peking-Tsinghua Center for Life Sciences,Beijing Key Laboratory of Cardiometabolic
文摘This paper develops manufacturer's channel selection models considering carbon emission reduction and remanufacturing. The models are based on the cap-and-trade system and consumer's preference for low-carbon product. We study the strategies of pricing and carbon emission reduction under three channel structures: pure online channel, pure offiine channel and dual channel. The results show that a higher recovery rate of remanufacturing can bring a higher reduction in carbon emission level and a lower price for consumers in the three channel structures. Compared to the pure online channel and pure offiine channel, the dual channel is the optimal selection for a for-profit manufacturer However, for a retailer, the pure offiine channel is more profitable than the dual channel. From the perspective of carbon emission reduction, the dual channel and the pure online channel generate the same effect; the pure offiine channel makes the highest reduction in carbon emission when consumers' acceptance for online channel is low. More managerial insights are provided in sensitivity analysis.
基金the National Key R&D Program of China(2022YFA1203304)the Natural Science Foundation of Jiangsu Province(BK20220288)+1 种基金Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(Start-up grant E1552102)the China Postdoctoral Science Foundation(No.2023M732553).
文摘The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a generalized channel structures strategy with optimized in situ polymerization technology in their recent study.The resultant FLBs can be woven into different-sized powering textiles,providing a high energy density output of 128 Wh kg^(-1) and simultaneously demonstrating good durability even under harsh conditions.Such a promising strategy expands the horizon in developing FLB with particular polymer gel electrolytes,and significantly ever-deepening understanding of the scaled wearable energy textile system toward a sustainable future.
基金Project supported by the National Natural Science Foun-dation of China(Grant No.51127006)
文摘The spatial relationship between the energy dissipation slabs and the vortex tubes is investigated based on the direct numerical simulation(DNS) of the channel flow. The spatial distance between these two structures is found to be slightly greater than the vortex radius. Comparison of the core areas of the vortex tubes and the dissipation slabs gives a mean ratio of 0.16 for the mean swirling strength and that of 2.89 for the mean dissipation rate. These results verify that in the channel flow the slabs of intense dissipation and the vortex tubes do not coincide in space. Rather they appear in pairs offset with a mean separation of approximately 10η.
文摘The impressive development of China's economy over the past few decades has enabled non-financial firms to adopt financial investment in exchange for enhanced financing behavior and short-term profit(shareholder value)maximization,while the persistence of fixed investment leading to dramatic capital accumulation has spurred the nation's rapid economic growth.The existing literature has extensive discussions on the crowd-out effect of financial activities on non-financial firms'fixed investment but overlooks to what extent and under what forces financial activities potentially benefit real investment.This paper investigates whether profits from financial activities have an inverted U-shape relationship with firms'fixed investment.In particular,we aim to identify if the benefit of financial profit on fixed investment is through the financial constraint channel and/or ownership structure channel for Chinese-listed firms from 2003 to 2018.We present robust evidence to support the inverted U-shape relationship between financial profit and fixed investment for the whole sample of firms as well as the split samples of firms(SOEs and non-SOEs).Moreover,among all channels including cash flow,debt financing,managerial shareholding,ownership concentration,and state ownership,this research documents that financial profit mainly benefits firms by reducing debt burden.Firms with concentrated ownership and strong state shareholding are also more likely to crowd-out real investment or potentially alleviate overinvestment.Nevertheless,non-SOEs are more prone to benefit from financial profits by reducing the debt overhang problem than SOEs,whereas ownership concentration for SOEs non-increments the crowd-out effect.