In this paper, we present an adaptive moving mesh technique for solvingthe incompressible viscous flows using the vorticity stream-function formulation. Themoving mesh strategy is based on the approach proposed by Li ...In this paper, we present an adaptive moving mesh technique for solvingthe incompressible viscous flows using the vorticity stream-function formulation. Themoving mesh strategy is based on the approach proposed by Li et al. [J. Comput. Phys.,170 (2001), pp. 562–588] to separate the mesh-moving and evolving PDE at each timestep. The Navier-Stokes equations are solved in the vorticity stream-function form bya finite-volume method in space, and the mesh-moving part is realized by solving theEuler-Lagrange equations to minimize a certain variation in conjunction with a moresophisticated monitor function. A conservative interpolation is used to redistributethe numerical solutions on the new meshes. This paper discusses the implementationof the periodic boundary conditions, where the physical domain is allowed to deformwith time while the computational domain remains fixed and regular throughout. Numericalresults demonstrate the accuracy and effectiveness of the proposed algorithm.展开更多
Heterostructured eutectic high-entropy alloys(EHEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture toughness.However,the toughening/strength...Heterostructured eutectic high-entropy alloys(EHEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture toughness.However,the toughening/strengthening mechanisms of these EHEAs have not been thoroughly investigated.In this study,we developed a series of dual-phase Al_((18–2x))Co_(30)Cr_((11+x))Fe_((11+x))Ni_(3)0(x=-1,0,1)eutectic and neareutectic HEAs containing face-centered cubic(FCC)and body-centered cubic(BCC)phases.Despite the high amount of BCC,which is referred to as the brittle phase,newly developed EHEAs exhibited superior fracture toughness.Interestingly,we discovered that a fully eutectic HEA exhibited further improvements in both yield stress and fracture toughness,outperforming our off-eutectic and other previously reported HEAs.By combining experiments and theoretical models,we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic HEA was derived from the high hetero-deformationinduced(HDI)strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.展开更多
The objective of this project is to improve the performance of the efficiency, thrust and lift of flapping wings in tandem arrangement. This research investigates the effect of the arrangement of the airfoils in tande...The objective of this project is to improve the performance of the efficiency, thrust and lift of flapping wings in tandem arrangement. This research investigates the effect of the arrangement of the airfoils in tandem on the performance of the airfoils by varying the phase difference and distance between the airfoils. Three flapping configurations from an earlier phase of a research which gives high efficiency, thrust and lift are used in the tandem simulation. It is found all the different flapping configurations show improvement in the efficiency, thrust or lift when the distance between the two airfoils and the phase angle between the heaving positions of the two airfoils are optimal. The average thrust coefficient of the tandem arrangement managed to attain more than twice that of the single one （4.84 vs. 2.05）. On the other hand, the average lift coefficient of the tandem arrangement also increased to 4.59, as compared to the original single airfoil value of 3.04. All these results obtained will aid in the design of a better ornithopter with tandem wing arrangement.展开更多
Stroke is a leading cause of death worldwide. Up to one thousand potential drugs or interventions have been developed to treat stroke, out of which;60 have gone on to clinical trials. However, none of them has been su...Stroke is a leading cause of death worldwide. Up to one thousand potential drugs or interventions have been developed to treat stroke, out of which;60 have gone on to clinical trials. However, none of them has been successful. New insights into the molecular and cellular mechanisms of ischemia-induced injury are needed for discovering new therapeutic targets. Recently, Drosophila has been used to uncover new hypoxia-related genes. In this study, we describe an efficient and reliable assay with a sophisticated apparatus for studying the effects of oxygen deprivation on flies. Using this assay, wild-type flies were exposed to an anoxic environment for varying lengths of time, then the cumulative death rate and mobility recovery were systematically analyzed. We found that anoxia for over one hour caused lethality. The cumulative death rate on day 5 after anoxia was linearly and positively correlatedwith the duration of anoxia, and reached 50% when the duration was 2.5 h–3 h. We also found that the mobility recovery in normoxia was slow, as the climbing ability remained largely unchanged 4 h–6 h after 2.5-h of anoxia.We suggest that 2.5 h–3 h of anoxia and 4 h–6 h of recovery before mobility analysis are appropriate for future use of the anoxia assay.展开更多
Simulations have been done to assess the lift, thrust and propulsive efficiency of different types of non-symmetrical airfoils under different flapping configurations. The variables involved are reduced frequency, Str...Simulations have been done to assess the lift, thrust and propulsive efficiency of different types of non-symmetrical airfoils under different flapping configurations. The variables involved are reduced frequency, Strouhal number, pitch amplitude and phase angle. In order to analyze the variables more efficiently, the design of experiments using the response surface methodology is applied. Results show that both the variables and shape of the airfoil have a profound effect on the lift, thrust, and efficiency. By using non- symmetrical airfoils, average lift coefficient as high as 2.23 can be obtained. The average thrust coefficient and efficiency also reach high values of 2.53 and 0.61, respectively. The lift production is highly dependent on the airfoil＇s shape while thrust production is influenced more heavily by the variables. Efficiency falls somewhere in between. Two-factor interac- tions are found to exist among the variables. This shows that it is not sufficient to analyze each variable individually. Vorticity diagrams are analyzed to explain the results obtained. Overall, the S1020 airfoil is able to provide relatively good efficiency and at the same time generate high thrust and lift force. These results aid in the design of a better ornithopter＇s wing.展开更多
The battery management system(BMS)is the main safeguard of a battery system for electric propulsion and machine electrifcation.It is tasked to ensure reliable and safe operation of battery cells connected to provide h...The battery management system(BMS)is the main safeguard of a battery system for electric propulsion and machine electrifcation.It is tasked to ensure reliable and safe operation of battery cells connected to provide high currents at high voltage levels.In addition to efectively monitoring all the electrical parameters of a battery pack system,such as the voltage,current,and temperature,the BMS is also used to improve the battery performance with proper safety measures within the system.With growing acceptance of lithium-ion batteries,major industry sectors such as the automotive,renewable energy,manufacturing,construction,and even some in the mining industry have brought forward the mass transition from fossil fuel dependency to electric powered machinery and redefned the world of energy storage.Hence,the functional safety considerations,which are those relating to automatic protection,in battery management for battery pack technologies are particularly important to ensure that the overall electrical system,regardless of whether it is for electric transportation or stationary energy storage,is in accordance with high standards of safety,reliability,and quality.If the system or product fails to meet functional and other safety requirements on account of faulty design or a sequence of failure events,then the environment,people,and property could be endangered.This paper analyzed the details of BMS for electric transportation and large-scale energy storage systems,particularly in areas concerned with hazardous environment.The analysis covers the aspect of functional safety that applies to BMS and is in accordance with the relevant industrial standards.A comprehensive evaluation of the components,architecture,risk reduction techniques,and failure mode analysis applicable to BMS operation was also presented.The article further provided recommendations on safety design and performance optimization in relation to the overall BMS integration.展开更多
An indirect-forcing immersed boundary method for solving the incompressible Navier-Stokes equations involving the interfaces and irregular domains is developed.The rigid boundaries and interfaces are represented by a ...An indirect-forcing immersed boundary method for solving the incompressible Navier-Stokes equations involving the interfaces and irregular domains is developed.The rigid boundaries and interfaces are represented by a number of Lagrangian control points.Stationary rigid boundaries are embedded in the Cartesian grid and singular forces at the rigid boundaries are applied to impose the prescribed velocity conditions.The singular forces at the interfaces and the rigid boundaries are then distributed to the nearby Cartesian grid points using the immersed boundary method.In the present work,the singular forces at the rigid boundaries are computed implicitly by solving a small system of equations at each time step to ensure that the prescribed velocity condition at the rigid boundary is satisfied exactly.For deformable interfaces,the forces that the interface exerts on the fluid are computed from the configuration of the elastic interface and are applied to the fluid.The Navier-Stokes equations are discretized using finite difference method on a staggered uniform Cartesian grid by a second order accurate projection method.The ability of the method to simulate viscous flows with interfaces on irregular domains is demonstrated by applying to the rotational flow problem,the relaxation of an elastic membrane and flow in a constriction with an immersed elastic membrane.展开更多
Abstract.In this paper,a novel implementation of immersed interface method combined with Stokes solver on a MAC staggered grid for solving the steady two-fluid Stokes equations with interfaces.The velocity components ...Abstract.In this paper,a novel implementation of immersed interface method combined with Stokes solver on a MAC staggered grid for solving the steady two-fluid Stokes equations with interfaces.The velocity components along the interface are introduced as two augmented variables and the resulting augmented equation is then solved by the GMRES method.The augmented variables and/or the forces are related to the jumps in pressure and the jumps in the derivatives of both pressure and velocity,and are interpolated using cubic splines and are then applied to the fluid through the jump conditions.The Stokes equations are discretized on a staggered Cartesian grid via a second order finite difference method and solved by the conjugate gradient Uzawa-typemethod.The numerical results show that the overall scheme is second order accurate.The major advantages of the present IIM-Stokes solver are the efficiency and flexibility in terms of types of fluid flow and different boundary conditions.The proposed method avoids solution of the pressure Poisson equation,and comparisons are made to show the advantages of time savings by the present method.The generalized two-phase Stokes solver with correction terms has also been applied to incompressible two-phase Navier-Stokes flow.展开更多
Phylogenetic relationships among Bornean sucker fishes(Teleostei:Balitoridae:Gastromyzontinae)were investigated by comparing cytochrome b gene sequences from eight species.The results were in general agreement with pr...Phylogenetic relationships among Bornean sucker fishes(Teleostei:Balitoridae:Gastromyzontinae)were investigated by comparing cytochrome b gene sequences from eight species.The results were in general agreement with previous morphology-based studies.It was found that the genera Gastromyzon and Neogastromyzon are both monophyletic and that the Chinese homalopterid Crossostoma lacustre(Homalopterinae)is not related to the Bornean species.This molecular-level study of cytochrome b gene variation in Bornean gastromyzontins will undoubtedly help to shed light on the molecular systematics of this unique freshwater fish.展开更多
Peach-like ZnO microstructures are synthesized using vapor phase transport on MgO(001)substrates with a copper oxide(60 nm)buffer layer.The structure and morphology of the product are investigated using an x-ray diffr...Peach-like ZnO microstructures are synthesized using vapor phase transport on MgO(001)substrates with a copper oxide(60 nm)buffer layer.The structure and morphology of the product are investigated using an x-ray diffractometer(XRD)and a field-emission scanning electron microscope.The peaches have an average diameter of 3μm and a wurtzite structure.To study the optical properties,photoluminescence(PL)and Raman spectroscopy are employed.A strong UV emission at 380 nm in the PL spectra is observed,and a sharp and dominant peak at 437 cm^(-1) in the Raman spectrum can be assigned to the good crystallization of obtained product.In addition,the growth mechanism of the peach-like ZnO structure is tentatively investigated based on the EDX analysis and growth time.展开更多
In this paper,an immersed interface method is presented to simulate the dynamics of inextensible interfaces in an incompressible flow.The tension is introduced as an augmented variable to satisfy the constraint of int...In this paper,an immersed interface method is presented to simulate the dynamics of inextensible interfaces in an incompressible flow.The tension is introduced as an augmented variable to satisfy the constraint of interface inextensibility,and the resulting augmented system is solved by the GMRES method.In this work,the arclength of the interface is locally and globally conserved as the enclosed region undergoes deformation.The forces at the interface are calculated from the configuration of the interface and the computed augmented variable,and then applied to the fluid through the related jump conditions.The governing equations are discretized on a MAC grid via a second-order finite difference scheme which incorporates jump contributions and solved by the conjugate gradient Uzawa-type method.The proposed method is applied to several examples including the deformation of a liquid capsule with inextensible interfaces in a shear flow.Numerical results reveal that both the area enclosed by interface and arclength of interface are conserved well simultaneously.These provide further evidence on the capability of the present method to simulate incompressible flows involving inextensible interfaces.展开更多
Pencil-like zinc oxide（ZnO） nanowire was synthesized on Si（111） substrate through a simple vapor phase method using a mixture of zinc oxide and graphite as the source material. The source inside a quartz tube crea...Pencil-like zinc oxide（ZnO） nanowire was synthesized on Si（111） substrate through a simple vapor phase method using a mixture of zinc oxide and graphite as the source material. The source inside a quartz tube created a Zn-rich vapor that facilitated the formation and growth of ZnO nanowires. Field emission scanning electron microscopic studies indicated that pencil-like ZnO nanowires had a size of the range from 50 to 150 nm in diameter and several microns in length. X-ray diffraction was used to investigate the crystal structure of ZnO nanowires. Raman scattering and photoluminescence were applied to characterize the optical properties of the pencils. The growth mechanism of the nanopencils was discussed based on the growth conditions.展开更多
In this paper, accurate and efficient simulation of cell motion in a biological fluid flow is investigated. The membrane of a moving cell is represented by athin shell composed of incompressible neo-Hookean elastic ma...In this paper, accurate and efficient simulation of cell motion in a biological fluid flow is investigated. The membrane of a moving cell is represented by athin shell composed of incompressible neo-Hookean elastic materials and the liquidsaround the membrane are approximated as incompressible Newtonian flows with lowReynolds numbers. The biofluid mechanics is approximated by the Stokes flow equations. A low-order BEM model is developed for the two biological fluids coupled atthe membrane surface. The moving boundary problem in fluid mechanics can be effectively solved using the BEM with a GMRES solver. The FEM model based on a flatthin shell element is further developed to predict the membrane load due to the largedeformation of a moving cell. Computational efficiency is greatly improved due tothe one-dimensional reduction in the present BEM and FEM models. The BEM solverfor the biological fluids is coupled with the FEM solver for the cell membrane at themembrane surface. The position of the membrane surface nodes is advanced in time byusing the classical fourth-order Runge-Kutta method. Numerical instability is avoidedby using a relatively small time step. Further numerical instabilities in the FEM solveris alleviated by using various techniques. The present method is applied to the FSIproblems of cell motion in a cylindrical flow. Numerical examples can illustrate thedistinct accuracy, efficiency and robustness of the present method. Furthermore, theimportance of bending stiffness of a cell membrane for stable cell motion simulation isemphasized. It is suggested that the present approach be an appealing alternative forsimulating the fluid-structure interaction of moving cells.展开更多
Nonalcoholic fatty liver disease (NAFLD) represents a rapidly growing cause of chronic liver disease in the United States and is associated with significant morbidity and mortality,including progression to liver cirrh...Nonalcoholic fatty liver disease (NAFLD) represents a rapidly growing cause of chronic liver disease in the United States and is associated with significant morbidity and mortality,including progression to liver cirrhosis and hepatocellular carcinoma.NAFLD comprises a spectrum of liver conditions,ranging from simple steatosis to steatosis with inflammation (steatohepatitis) and progressive fibrosis.Weight loss represents a first line therapeutic modality for the management of NAFLD.Herein,we review the evidence base for medical,surgical,and endoscopic approaches to weight loss and their potential impact on the natural history of NAFLD.展开更多
Non-alcoholic steatohepatitis(NASH)results from inflammation and hepatocyte injury in the setting of hepatic steatosis.Non-alcoholic steatohepatitis increases the risk of progression to liver fibrosis and cirrhosis,an...Non-alcoholic steatohepatitis(NASH)results from inflammation and hepatocyte injury in the setting of hepatic steatosis.Non-alcoholic steatohepatitis increases the risk of progression to liver fibrosis and cirrhosis,and is the most rapidly growing etiology for liver failure and indication for liver transplantation in the USA.Weight loss and lifestyle modification remain the standard first-line treatment,as no USA Food and Drug Administration-approved pharmacotherapy currently exists.The past decade has seen an explosion of interest in drug development targeting pathologic pathways in non-alcoholic steatohepatitis,with numerous phase 2 and 3 trials currently in progress.Here,we concisely review the major targets and mechanisms of action by class,summarize results from com-pleted pivotal phase 2 studies,and provide a detailed outline of key active studies with trial data for drugs in development,including obeticholic acid,elafibranor,cenicriviroc and selonsertib.展开更多
Budd-Chiari syndrome(BCS)is a rare disease consisting of obstruction of the hepatic venous outflow tract,which can occur at any level ranging from small hepatic veins to the inferior vena cava(1-4).BCS can result from...Budd-Chiari syndrome(BCS)is a rare disease consisting of obstruction of the hepatic venous outflow tract,which can occur at any level ranging from small hepatic veins to the inferior vena cava(1-4).BCS can result from intravascular thrombosis or membranous obstruction of the hepatic venous outflow tract,or,less commonly,due to external compression from tumors,nodules,abscesses,cysts,or other intrahepatic lesions(1-3).展开更多
To address the increasing need for detecting and validating protein biomarkers in clinical specimens,mass spectrometry(MS)-based targeted proteomic techniques,including the selected reaction monitoring(SRM),parallel r...To address the increasing need for detecting and validating protein biomarkers in clinical specimens,mass spectrometry(MS)-based targeted proteomic techniques,including the selected reaction monitoring(SRM),parallel reaction monitoring(PRM),and massively parallel dataindependent acquisition(DIA),have been developed.For optimal performance,they require the fragment ion spectra of targeted peptides as prior knowledge.In this report,we describe a MS pipeline and spectral resource to support targeted proteomics studies for human tissue samples.To build the spectral resource,we integrated common open-source MS computational tools to assemble a freely accessible computational workflow based on Docker.We then applied the workflow to generate DPHL,a comprehensive DIA pan-human library,from 1096 data-dependent acquisition(DDA)MS raw files for 16 types of cancer samples.This extensive spectral resource was then applied to a proteomic study of 17 prostate cancer(PCa)patients.Thereafter,PRM validation was applied to a larger study of 57 PCa patients and the differential expression of three proteins in prostate tumor was validated.As a second application,the DPHL spectral resource was applied to a study consisting of plasma samples from 19 diffuse large B cell lymphoma(DLBCL)patients and 18 healthy control subjects.Differentially expressed proteins between DLBCL patients and healthy control subjects were detected by DIA-MS and confirmed by PRM.These data demonstrate that the DPHL supports DIA and PRM MS pipelines for robust protein biomarker discovery.DPHL is freely accessible at https://www.iprox.org/page/project.html?id=IPX0001400000.展开更多
Recent reports of acute hepatitis of unknown origin in previously healthy children have been increasing worldwide.The main characteristics of the affected children were jaundice and gastrointestinal symptoms.Their ser...Recent reports of acute hepatitis of unknown origin in previously healthy children have been increasing worldwide.The main characteristics of the affected children were jaundice and gastrointestinal symptoms.Their serum aminotransaminase levels were above 500 IU/L,with negative tests for hepatitis viruses A–E.By 31 May 2022,the outbreak had affected over 800 children under the age of 16 years in more than 40 countries,resulting in acute liver failure in approximately 10%,including at least 21 deaths and 38 patients requiring liver transplantation.There was still no confirmed cause or causes,although there were several different working hypotheses,such as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),adenovirus serotype 41,or SARS-CoV-2 superantigen-mediated immune cell activation.Here,we review early observations of the 2022 outbreak which may inform diagnosis,treatment,and prevention in the context of an overlapping COVID-19 pandemic.展开更多
文摘In this paper, we present an adaptive moving mesh technique for solvingthe incompressible viscous flows using the vorticity stream-function formulation. Themoving mesh strategy is based on the approach proposed by Li et al. [J. Comput. Phys.,170 (2001), pp. 562–588] to separate the mesh-moving and evolving PDE at each timestep. The Navier-Stokes equations are solved in the vorticity stream-function form bya finite-volume method in space, and the mesh-moving part is realized by solving theEuler-Lagrange equations to minimize a certain variation in conjunction with a moresophisticated monitor function. A conservative interpolation is used to redistributethe numerical solutions on the new meshes. This paper discusses the implementationof the periodic boundary conditions, where the physical domain is allowed to deformwith time while the computational domain remains fixed and regular throughout. Numericalresults demonstrate the accuracy and effectiveness of the proposed algorithm.
基金supported by the National Research Foundation of Korea(No.NRF-2021R1A6A3A0108674211)the Fundamental Research Program of the Korean Institute of Materials Science(No.PNK8730)by Research Grant Council(RGC),Hong Kong Government,through General Research Fund(Nos.CityU11213118,CityU11200719 and CityU11209317).
文摘Heterostructured eutectic high-entropy alloys(EHEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture toughness.However,the toughening/strengthening mechanisms of these EHEAs have not been thoroughly investigated.In this study,we developed a series of dual-phase Al_((18–2x))Co_(30)Cr_((11+x))Fe_((11+x))Ni_(3)0(x=-1,0,1)eutectic and neareutectic HEAs containing face-centered cubic(FCC)and body-centered cubic(BCC)phases.Despite the high amount of BCC,which is referred to as the brittle phase,newly developed EHEAs exhibited superior fracture toughness.Interestingly,we discovered that a fully eutectic HEA exhibited further improvements in both yield stress and fracture toughness,outperforming our off-eutectic and other previously reported HEAs.By combining experiments and theoretical models,we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic HEA was derived from the high hetero-deformationinduced(HDI)strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.
文摘The objective of this project is to improve the performance of the efficiency, thrust and lift of flapping wings in tandem arrangement. This research investigates the effect of the arrangement of the airfoils in tandem on the performance of the airfoils by varying the phase difference and distance between the airfoils. Three flapping configurations from an earlier phase of a research which gives high efficiency, thrust and lift are used in the tandem simulation. It is found all the different flapping configurations show improvement in the efficiency, thrust or lift when the distance between the two airfoils and the phase angle between the heaving positions of the two airfoils are optimal. The average thrust coefficient of the tandem arrangement managed to attain more than twice that of the single one （4.84 vs. 2.05）. On the other hand, the average lift coefficient of the tandem arrangement also increased to 4.59, as compared to the original single airfoil value of 3.04. All these results obtained will aid in the design of a better ornithopter with tandem wing arrangement.
基金supported by the National Key Basic Research Program of China(2013CB530900)the National Natural Science Foundation of China(81371400 and 81771416)Shanghai Municipal Commission of Health and Family Planning(201740153)
文摘Stroke is a leading cause of death worldwide. Up to one thousand potential drugs or interventions have been developed to treat stroke, out of which;60 have gone on to clinical trials. However, none of them has been successful. New insights into the molecular and cellular mechanisms of ischemia-induced injury are needed for discovering new therapeutic targets. Recently, Drosophila has been used to uncover new hypoxia-related genes. In this study, we describe an efficient and reliable assay with a sophisticated apparatus for studying the effects of oxygen deprivation on flies. Using this assay, wild-type flies were exposed to an anoxic environment for varying lengths of time, then the cumulative death rate and mobility recovery were systematically analyzed. We found that anoxia for over one hour caused lethality. The cumulative death rate on day 5 after anoxia was linearly and positively correlatedwith the duration of anoxia, and reached 50% when the duration was 2.5 h–3 h. We also found that the mobility recovery in normoxia was slow, as the climbing ability remained largely unchanged 4 h–6 h after 2.5-h of anoxia.We suggest that 2.5 h–3 h of anoxia and 4 h–6 h of recovery before mobility analysis are appropriate for future use of the anoxia assay.
文摘Simulations have been done to assess the lift, thrust and propulsive efficiency of different types of non-symmetrical airfoils under different flapping configurations. The variables involved are reduced frequency, Strouhal number, pitch amplitude and phase angle. In order to analyze the variables more efficiently, the design of experiments using the response surface methodology is applied. Results show that both the variables and shape of the airfoil have a profound effect on the lift, thrust, and efficiency. By using non- symmetrical airfoils, average lift coefficient as high as 2.23 can be obtained. The average thrust coefficient and efficiency also reach high values of 2.53 and 0.61, respectively. The lift production is highly dependent on the airfoil＇s shape while thrust production is influenced more heavily by the variables. Efficiency falls somewhere in between. Two-factor interac- tions are found to exist among the variables. This shows that it is not sufficient to analyze each variable individually. Vorticity diagrams are analyzed to explain the results obtained. Overall, the S1020 airfoil is able to provide relatively good efficiency and at the same time generate high thrust and lift force. These results aid in the design of a better ornithopter＇s wing.
基金supported by Azure Mining Technology,CCTEG,and the University of Wollongong.
文摘The battery management system(BMS)is the main safeguard of a battery system for electric propulsion and machine electrifcation.It is tasked to ensure reliable and safe operation of battery cells connected to provide high currents at high voltage levels.In addition to efectively monitoring all the electrical parameters of a battery pack system,such as the voltage,current,and temperature,the BMS is also used to improve the battery performance with proper safety measures within the system.With growing acceptance of lithium-ion batteries,major industry sectors such as the automotive,renewable energy,manufacturing,construction,and even some in the mining industry have brought forward the mass transition from fossil fuel dependency to electric powered machinery and redefned the world of energy storage.Hence,the functional safety considerations,which are those relating to automatic protection,in battery management for battery pack technologies are particularly important to ensure that the overall electrical system,regardless of whether it is for electric transportation or stationary energy storage,is in accordance with high standards of safety,reliability,and quality.If the system or product fails to meet functional and other safety requirements on account of faulty design or a sequence of failure events,then the environment,people,and property could be endangered.This paper analyzed the details of BMS for electric transportation and large-scale energy storage systems,particularly in areas concerned with hazardous environment.The analysis covers the aspect of functional safety that applies to BMS and is in accordance with the relevant industrial standards.A comprehensive evaluation of the components,architecture,risk reduction techniques,and failure mode analysis applicable to BMS operation was also presented.The article further provided recommendations on safety design and performance optimization in relation to the overall BMS integration.
基金The last author’s research is supported by the grant AcRF RG59/08 M52110092.
文摘An indirect-forcing immersed boundary method for solving the incompressible Navier-Stokes equations involving the interfaces and irregular domains is developed.The rigid boundaries and interfaces are represented by a number of Lagrangian control points.Stationary rigid boundaries are embedded in the Cartesian grid and singular forces at the rigid boundaries are applied to impose the prescribed velocity conditions.The singular forces at the interfaces and the rigid boundaries are then distributed to the nearby Cartesian grid points using the immersed boundary method.In the present work,the singular forces at the rigid boundaries are computed implicitly by solving a small system of equations at each time step to ensure that the prescribed velocity condition at the rigid boundary is satisfied exactly.For deformable interfaces,the forces that the interface exerts on the fluid are computed from the configuration of the elastic interface and are applied to the fluid.The Navier-Stokes equations are discretized using finite difference method on a staggered uniform Cartesian grid by a second order accurate projection method.The ability of the method to simulate viscous flows with interfaces on irregular domains is demonstrated by applying to the rotational flow problem,the relaxation of an elastic membrane and flow in a constriction with an immersed elastic membrane.
基金supported by Guangdong Provincial Government of China through the“Computational Science Innovative Research Team”program and the Sun Yat-sen University“Hundred Talents Program”(34000-3181201)and the National Natural Science Foundation of China(No.11101446).
文摘Abstract.In this paper,a novel implementation of immersed interface method combined with Stokes solver on a MAC staggered grid for solving the steady two-fluid Stokes equations with interfaces.The velocity components along the interface are introduced as two augmented variables and the resulting augmented equation is then solved by the GMRES method.The augmented variables and/or the forces are related to the jumps in pressure and the jumps in the derivatives of both pressure and velocity,and are interpolated using cubic splines and are then applied to the fluid through the jump conditions.The Stokes equations are discretized on a staggered Cartesian grid via a second order finite difference method and solved by the conjugate gradient Uzawa-typemethod.The numerical results show that the overall scheme is second order accurate.The major advantages of the present IIM-Stokes solver are the efficiency and flexibility in terms of types of fluid flow and different boundary conditions.The proposed method avoids solution of the pressure Poisson equation,and comparisons are made to show the advantages of time savings by the present method.The generalized two-phase Stokes solver with correction terms has also been applied to incompressible two-phase Navier-Stokes flow.
文摘Phylogenetic relationships among Bornean sucker fishes(Teleostei:Balitoridae:Gastromyzontinae)were investigated by comparing cytochrome b gene sequences from eight species.The results were in general agreement with previous morphology-based studies.It was found that the genera Gastromyzon and Neogastromyzon are both monophyletic and that the Chinese homalopterid Crossostoma lacustre(Homalopterinae)is not related to the Bornean species.This molecular-level study of cytochrome b gene variation in Bornean gastromyzontins will undoubtedly help to shed light on the molecular systematics of this unique freshwater fish.
基金Supported by the Exploratory Research of Malaysia under Grant No ERGS/11/STG/UPM/01/3.
文摘Peach-like ZnO microstructures are synthesized using vapor phase transport on MgO(001)substrates with a copper oxide(60 nm)buffer layer.The structure and morphology of the product are investigated using an x-ray diffractometer(XRD)and a field-emission scanning electron microscope.The peaches have an average diameter of 3μm and a wurtzite structure.To study the optical properties,photoluminescence(PL)and Raman spectroscopy are employed.A strong UV emission at 380 nm in the PL spectra is observed,and a sharp and dominant peak at 437 cm^(-1) in the Raman spectrum can be assigned to the good crystallization of obtained product.In addition,the growth mechanism of the peach-like ZnO structure is tentatively investigated based on the EDX analysis and growth time.
基金The authors would like to thank the referees for the valuable suggestions on the revision of the manuscript.The research of the first author was partially supported by Guangdong Provincial Government of China through the“Computational Science Innovative Research Team”program,the Sun Yat-sen University“Hundred Talents Program”(34000-3181201)the National Natural Science Foundation of China(No.11101446).
文摘In this paper,an immersed interface method is presented to simulate the dynamics of inextensible interfaces in an incompressible flow.The tension is introduced as an augmented variable to satisfy the constraint of interface inextensibility,and the resulting augmented system is solved by the GMRES method.In this work,the arclength of the interface is locally and globally conserved as the enclosed region undergoes deformation.The forces at the interface are calculated from the configuration of the interface and the computed augmented variable,and then applied to the fluid through the related jump conditions.The governing equations are discretized on a MAC grid via a second-order finite difference scheme which incorporates jump contributions and solved by the conjugate gradient Uzawa-type method.The proposed method is applied to several examples including the deformation of a liquid capsule with inextensible interfaces in a shear flow.Numerical results reveal that both the area enclosed by interface and arclength of interface are conserved well simultaneously.These provide further evidence on the capability of the present method to simulate incompressible flows involving inextensible interfaces.
基金supported by the Universiti Putra Malaysia through Grant Nos
文摘Pencil-like zinc oxide（ZnO） nanowire was synthesized on Si（111） substrate through a simple vapor phase method using a mixture of zinc oxide and graphite as the source material. The source inside a quartz tube created a Zn-rich vapor that facilitated the formation and growth of ZnO nanowires. Field emission scanning electron microscopic studies indicated that pencil-like ZnO nanowires had a size of the range from 50 to 150 nm in diameter and several microns in length. X-ray diffraction was used to investigate the crystal structure of ZnO nanowires. Raman scattering and photoluminescence were applied to characterize the optical properties of the pencils. The growth mechanism of the nanopencils was discussed based on the growth conditions.
文摘In this paper, accurate and efficient simulation of cell motion in a biological fluid flow is investigated. The membrane of a moving cell is represented by athin shell composed of incompressible neo-Hookean elastic materials and the liquidsaround the membrane are approximated as incompressible Newtonian flows with lowReynolds numbers. The biofluid mechanics is approximated by the Stokes flow equations. A low-order BEM model is developed for the two biological fluids coupled atthe membrane surface. The moving boundary problem in fluid mechanics can be effectively solved using the BEM with a GMRES solver. The FEM model based on a flatthin shell element is further developed to predict the membrane load due to the largedeformation of a moving cell. Computational efficiency is greatly improved due tothe one-dimensional reduction in the present BEM and FEM models. The BEM solverfor the biological fluids is coupled with the FEM solver for the cell membrane at themembrane surface. The position of the membrane surface nodes is advanced in time byusing the classical fourth-order Runge-Kutta method. Numerical instability is avoidedby using a relatively small time step. Further numerical instabilities in the FEM solveris alleviated by using various techniques. The present method is applied to the FSIproblems of cell motion in a cylindrical flow. Numerical examples can illustrate thedistinct accuracy, efficiency and robustness of the present method. Furthermore, theimportance of bending stiffness of a cell membrane for stable cell motion simulation isemphasized. It is suggested that the present approach be an appealing alternative forsimulating the fluid-structure interaction of moving cells.
文摘Nonalcoholic fatty liver disease (NAFLD) represents a rapidly growing cause of chronic liver disease in the United States and is associated with significant morbidity and mortality,including progression to liver cirrhosis and hepatocellular carcinoma.NAFLD comprises a spectrum of liver conditions,ranging from simple steatosis to steatosis with inflammation (steatohepatitis) and progressive fibrosis.Weight loss represents a first line therapeutic modality for the management of NAFLD.Herein,we review the evidence base for medical,surgical,and endoscopic approaches to weight loss and their potential impact on the natural history of NAFLD.
文摘Non-alcoholic steatohepatitis(NASH)results from inflammation and hepatocyte injury in the setting of hepatic steatosis.Non-alcoholic steatohepatitis increases the risk of progression to liver fibrosis and cirrhosis,and is the most rapidly growing etiology for liver failure and indication for liver transplantation in the USA.Weight loss and lifestyle modification remain the standard first-line treatment,as no USA Food and Drug Administration-approved pharmacotherapy currently exists.The past decade has seen an explosion of interest in drug development targeting pathologic pathways in non-alcoholic steatohepatitis,with numerous phase 2 and 3 trials currently in progress.Here,we concisely review the major targets and mechanisms of action by class,summarize results from com-pleted pivotal phase 2 studies,and provide a detailed outline of key active studies with trial data for drugs in development,including obeticholic acid,elafibranor,cenicriviroc and selonsertib.
文摘Budd-Chiari syndrome(BCS)is a rare disease consisting of obstruction of the hepatic venous outflow tract,which can occur at any level ranging from small hepatic veins to the inferior vena cava(1-4).BCS can result from intravascular thrombosis or membranous obstruction of the hepatic venous outflow tract,or,less commonly,due to external compression from tumors,nodules,abscesses,cysts,or other intrahepatic lesions(1-3).
基金supported by the National Natural Science Foundation of China(Grant No.81972492)National Science Fund for Young Scholars(Grant No.21904107)+7 种基金Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars(Grant No.LR19C050001)Hangzhou Agriculture and Society Advancement Program(Grant No.20190101A04)Westlake Startup Grantresearch funds from the National Cancer Centre Singapore and Singapore General Hospital,Singaporethe National Key R&D Program of China(Grant No.2016YFC0901704)Zhejiang Innovation Discipline Project of Laboratory Animal Genetic Engineering(Grant No.201510)the Netherlands Cancer Society(Grant No.NKI 2014-6651)The Netherlands Organization for Scientific Research(NWO)-Middelgroot(Grant No.91116017)
文摘To address the increasing need for detecting and validating protein biomarkers in clinical specimens,mass spectrometry(MS)-based targeted proteomic techniques,including the selected reaction monitoring(SRM),parallel reaction monitoring(PRM),and massively parallel dataindependent acquisition(DIA),have been developed.For optimal performance,they require the fragment ion spectra of targeted peptides as prior knowledge.In this report,we describe a MS pipeline and spectral resource to support targeted proteomics studies for human tissue samples.To build the spectral resource,we integrated common open-source MS computational tools to assemble a freely accessible computational workflow based on Docker.We then applied the workflow to generate DPHL,a comprehensive DIA pan-human library,from 1096 data-dependent acquisition(DDA)MS raw files for 16 types of cancer samples.This extensive spectral resource was then applied to a proteomic study of 17 prostate cancer(PCa)patients.Thereafter,PRM validation was applied to a larger study of 57 PCa patients and the differential expression of three proteins in prostate tumor was validated.As a second application,the DPHL spectral resource was applied to a study consisting of plasma samples from 19 diffuse large B cell lymphoma(DLBCL)patients and 18 healthy control subjects.Differentially expressed proteins between DLBCL patients and healthy control subjects were detected by DIA-MS and confirmed by PRM.These data demonstrate that the DPHL supports DIA and PRM MS pipelines for robust protein biomarker discovery.DPHL is freely accessible at https://www.iprox.org/page/project.html?id=IPX0001400000.
基金support from the National Key Research and Development Program of China(2021YFC2700802)the National Natural Science Foundation of China(81873565,82170593)。
文摘Recent reports of acute hepatitis of unknown origin in previously healthy children have been increasing worldwide.The main characteristics of the affected children were jaundice and gastrointestinal symptoms.Their serum aminotransaminase levels were above 500 IU/L,with negative tests for hepatitis viruses A–E.By 31 May 2022,the outbreak had affected over 800 children under the age of 16 years in more than 40 countries,resulting in acute liver failure in approximately 10%,including at least 21 deaths and 38 patients requiring liver transplantation.There was still no confirmed cause or causes,although there were several different working hypotheses,such as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),adenovirus serotype 41,or SARS-CoV-2 superantigen-mediated immune cell activation.Here,we review early observations of the 2022 outbreak which may inform diagnosis,treatment,and prevention in the context of an overlapping COVID-19 pandemic.
