The main objective of this research was to examine the suitability of aluminium alloy to design a piston of an internal combustion engine for improvement in weight and cost reduction. The piston was modelled using Aut...The main objective of this research was to examine the suitability of aluminium alloy to design a piston of an internal combustion engine for improvement in weight and cost reduction. The piston was modelled using Autodesk Inventor 2017 software. The modelled piston was then imported into Ansys for further analysis. Static structural and thermal analysis were carried out on the pistons of the four different materials namely: Al 413 alloy, Al 384 alloy, Al 390 alloy and Al332 alloy to determine the total deformation, equivalent Von Mises stress, maximum shear stress, and the safety factor. The results of the study revealed that, aluminium 332 alloy piston deformed less compared to the deformations of aluminium 390 alloy piston, aluminium 384 alloy piston and aluminium 413 alloy piston. The induced Von Mises stresses in the pistons of the four different materials were found to be far lower than the yield strengths of all the materials. Hence, all the selected materials including the implementing material have equal properties to withstand the maximum gas load. All the selected materials were observed to have high thermal conductivity enough to be able to withstand the operating temperature in the engine cylinders.展开更多
The subject of the Holocaust appeared in Israeli art from the establishment of the State and onwards. The integration of the Holocaust in Israeli art through the years was influenced by Israeli society and the Israeli...The subject of the Holocaust appeared in Israeli art from the establishment of the State and onwards. The integration of the Holocaust in Israeli art through the years was influenced by Israeli society and the Israeli art institutional attitude towards the subject and by local historical events. As a result, we witness a development of two directions in Israeli art concerning the Holocaust. One of them has two facets： a massive use of images emphasizing the enormous personal as well as collective destruction of the Jewish nation as the ultimate victim that ＂the entire world is against us＂; While the other facet is that despite the Jewish people emerge battered and humiliated from the Holocaust, they built a country to be an immovable, permanent and safe place for the Jewish nation since ＂there is no one else except for us to do it＂. The other direction regarding the Holocaust that developed in Israeli art, examining in an universal approach the Israeli response to the Holocaust through the prism of local historical events occurring since the establishment of the State. Therefore, we see imagery that examines the aggressive impression of the Israelis, as an internal as well as external criticism of what seems as aggression and violence against another nation. In Israel, as well as in other Modem states, art is used as a means for expression of different viewpoints. In this article, I am focusing on the artistic references to the above approaches to the Holocaust.展开更多
In this paper,we present optimal error estimates of the local discontinuous Galerkin method with generalized numerical fluxes for one-dimensional nonlinear convection-diffusion systems.The upwind-biased flux with the ...In this paper,we present optimal error estimates of the local discontinuous Galerkin method with generalized numerical fluxes for one-dimensional nonlinear convection-diffusion systems.The upwind-biased flux with the adjustable numerical viscosity for the convective term is chosen based on the local characteristic decomposition,which is helpful in resolving discontinuities of degenerate parabolic equations without enforcing any limiting procedure.For the diffusive term,a pair of generalized alternating fluxes is considered.By constructing and analyzing generalized Gauss-Radau projections with respect to different convective or diffusive terms,we derive optimal error estimates for nonlinear convection-diffusion systems with the symmetrizable flux Jacobian and fully nonlinear diffusive problems.Numerical experiments including long time simulations,different boundary conditions and degenerate equations with discontinuous initial data are provided to demonstrate the sharpness of theoretical results.展开更多
Background:The lateral movements of mass and energy across the terrestrial-aquatic interface are being increasingly recognized for their importance in the carbon(C)balance of coastal/estuarine wetlands.We quantifed th...Background:The lateral movements of mass and energy across the terrestrial-aquatic interface are being increasingly recognized for their importance in the carbon(C)balance of coastal/estuarine wetlands.We quantifed the lateral fux of detrital C in the Yangtze estuary where invasive Spartina alternifora has substantially and extensively altered the ecosystem structure and functions.Our overall objective was to close the C budget of estuarine wetlands through feld sampling,tower-based measurements,and modeling.Methods:A lateral detrital C exchange evaluation platform was established in a case study of the Yangtze River Estuary to investigate the efect of ecosystem structural changes on lateral detrital C transfer processes.This study estimated the lateral detrital C exchange based on the gross primary production(GPP)by performing coupled modeling and feld sampling.Tower-based measurements and MODIS time series and CH4 outgassing and biomass simultaneously measured the lateral detrital C fux to characterize the relative contributions of lateral(i.e.,detritus)C fuxes to the annual marsh C budget.Results:The C pools in the plants and soil of Spartina marshes were signifcantly higher than those of the native community dominated by Phragmites australis.The GPP based on MODIS(GPPMODIS)was 472.6 g C m^(−2) year^(−1) and accounted for 73.0%of the GPP estimated from eddy covariance towers(GPPEC)(646.9±70.7 g C m^(−2) year^(−1)).We also detected a higher GPPMODIS during the pre-growing season,which exhibited a similar lateral detrital C fux magnitude.On average,25.8%of the net primary production(NPP),which ranged from 0.21 to 0.30 kg C m^(−2) year^(−1),was exported during lateral exchange.The annual C loss as CH4 was estimated to be 17.9±3.7 g C m^(−2) year^(−1),accounting for 2.8%of the GPPEC.The net positive detrital C fux(i.e.,more detritus leaving the wetlands),which could exceed 0.16 kg C m^(−2) day^(-1),was related to daily tides.However,the observed lateral detrital C fux based on monthly sampling was 73.5%higher than that based on daily sampling(i.e.,the sum of daily sampling),particularly in March and October.In addition,spatiotemporal granularities were responsible for most of the uncertainty in the lateral detrital C exchange.Conclusion:This research demonstrated that an integrated framework incorporating modeling and feld sampling can quantitatively assess lateral detrital C transport processes across the terrestrial-aquatic interface in estuarine wetlands.However,we note some limitations in the application of the light-use efciency model to tidal wetlands.Spartina invasion can turn the lateral C balance from a C source(209.0 g C m^(−2) year^(−1))of Phragmites-dominated marshes into a small C sink(-31.0 g C m^(−2) year^(−1)).Sampling over a more extended period and continuous measurements are essential for determining the contribution of diferent lateral detrital C fux processes to closing the ecosystem C budgets.The sampling spatiotemporal granularities can be key to assessing lateral detrital C transfer.展开更多
Objective To investigate the etiology,clinical features and outcome of hospitalized patients with bloodstream infections(BSIs)in a tertiary hospital.MethodsPositive blood cultures were obtained from the microbiologica...Objective To investigate the etiology,clinical features and outcome of hospitalized patients with bloodstream infections(BSIs)in a tertiary hospital.MethodsPositive blood cultures were obtained from the microbiological laboratory in Fuxing Hospital,Capital Medical University from January 1,2012 to December 31,2012.展开更多
文摘The main objective of this research was to examine the suitability of aluminium alloy to design a piston of an internal combustion engine for improvement in weight and cost reduction. The piston was modelled using Autodesk Inventor 2017 software. The modelled piston was then imported into Ansys for further analysis. Static structural and thermal analysis were carried out on the pistons of the four different materials namely: Al 413 alloy, Al 384 alloy, Al 390 alloy and Al332 alloy to determine the total deformation, equivalent Von Mises stress, maximum shear stress, and the safety factor. The results of the study revealed that, aluminium 332 alloy piston deformed less compared to the deformations of aluminium 390 alloy piston, aluminium 384 alloy piston and aluminium 413 alloy piston. The induced Von Mises stresses in the pistons of the four different materials were found to be far lower than the yield strengths of all the materials. Hence, all the selected materials including the implementing material have equal properties to withstand the maximum gas load. All the selected materials were observed to have high thermal conductivity enough to be able to withstand the operating temperature in the engine cylinders.
文摘The subject of the Holocaust appeared in Israeli art from the establishment of the State and onwards. The integration of the Holocaust in Israeli art through the years was influenced by Israeli society and the Israeli art institutional attitude towards the subject and by local historical events. As a result, we witness a development of two directions in Israeli art concerning the Holocaust. One of them has two facets： a massive use of images emphasizing the enormous personal as well as collective destruction of the Jewish nation as the ultimate victim that ＂the entire world is against us＂; While the other facet is that despite the Jewish people emerge battered and humiliated from the Holocaust, they built a country to be an immovable, permanent and safe place for the Jewish nation since ＂there is no one else except for us to do it＂. The other direction regarding the Holocaust that developed in Israeli art, examining in an universal approach the Israeli response to the Holocaust through the prism of local historical events occurring since the establishment of the State. Therefore, we see imagery that examines the aggressive impression of the Israelis, as an internal as well as external criticism of what seems as aggression and violence against another nation. In Israel, as well as in other Modem states, art is used as a means for expression of different viewpoints. In this article, I am focusing on the artistic references to the above approaches to the Holocaust.
基金supported by National Natural Science Foundation of China(Grant Nos.11971132 and 11971131)Natural Science Foundation of Heilongjiang Province(Grant No.YQ2021A002)Guangdong Basic and Applied Basic Research Foundation(Grant No.2020B1515310006)。
文摘In this paper,we present optimal error estimates of the local discontinuous Galerkin method with generalized numerical fluxes for one-dimensional nonlinear convection-diffusion systems.The upwind-biased flux with the adjustable numerical viscosity for the convective term is chosen based on the local characteristic decomposition,which is helpful in resolving discontinuities of degenerate parabolic equations without enforcing any limiting procedure.For the diffusive term,a pair of generalized alternating fluxes is considered.By constructing and analyzing generalized Gauss-Radau projections with respect to different convective or diffusive terms,we derive optimal error estimates for nonlinear convection-diffusion systems with the symmetrizable flux Jacobian and fully nonlinear diffusive problems.Numerical experiments including long time simulations,different boundary conditions and degenerate equations with discontinuous initial data are provided to demonstrate the sharpness of theoretical results.
基金supported by the Open Research Fund of the State Key Laboratory of Estuarine and Coastal Research(Grant No.SKLEC-KF201912)the Foundation of Key Laboratory of Yangtze River Water Environment,Ministry of Education(Tongji University),China,(Grant No.YRWEF202105)+3 种基金the Natural Science Fund of Shanghai(Grant No.19ZR1470300)the Natural Science Foundation of China(Grant No.32071584)the Special Fund for Natural Resources Development of Jiangsu Province(Marine Science and Technology Innovation)(Grant No.JSZRHYKJ202109)the Central Public-interest Scientifc Institution Basal Research Fund,ECSFR,CAFS(Grant No.2021M04).
文摘Background:The lateral movements of mass and energy across the terrestrial-aquatic interface are being increasingly recognized for their importance in the carbon(C)balance of coastal/estuarine wetlands.We quantifed the lateral fux of detrital C in the Yangtze estuary where invasive Spartina alternifora has substantially and extensively altered the ecosystem structure and functions.Our overall objective was to close the C budget of estuarine wetlands through feld sampling,tower-based measurements,and modeling.Methods:A lateral detrital C exchange evaluation platform was established in a case study of the Yangtze River Estuary to investigate the efect of ecosystem structural changes on lateral detrital C transfer processes.This study estimated the lateral detrital C exchange based on the gross primary production(GPP)by performing coupled modeling and feld sampling.Tower-based measurements and MODIS time series and CH4 outgassing and biomass simultaneously measured the lateral detrital C fux to characterize the relative contributions of lateral(i.e.,detritus)C fuxes to the annual marsh C budget.Results:The C pools in the plants and soil of Spartina marshes were signifcantly higher than those of the native community dominated by Phragmites australis.The GPP based on MODIS(GPPMODIS)was 472.6 g C m^(−2) year^(−1) and accounted for 73.0%of the GPP estimated from eddy covariance towers(GPPEC)(646.9±70.7 g C m^(−2) year^(−1)).We also detected a higher GPPMODIS during the pre-growing season,which exhibited a similar lateral detrital C fux magnitude.On average,25.8%of the net primary production(NPP),which ranged from 0.21 to 0.30 kg C m^(−2) year^(−1),was exported during lateral exchange.The annual C loss as CH4 was estimated to be 17.9±3.7 g C m^(−2) year^(−1),accounting for 2.8%of the GPPEC.The net positive detrital C fux(i.e.,more detritus leaving the wetlands),which could exceed 0.16 kg C m^(−2) day^(-1),was related to daily tides.However,the observed lateral detrital C fux based on monthly sampling was 73.5%higher than that based on daily sampling(i.e.,the sum of daily sampling),particularly in March and October.In addition,spatiotemporal granularities were responsible for most of the uncertainty in the lateral detrital C exchange.Conclusion:This research demonstrated that an integrated framework incorporating modeling and feld sampling can quantitatively assess lateral detrital C transport processes across the terrestrial-aquatic interface in estuarine wetlands.However,we note some limitations in the application of the light-use efciency model to tidal wetlands.Spartina invasion can turn the lateral C balance from a C source(209.0 g C m^(−2) year^(−1))of Phragmites-dominated marshes into a small C sink(-31.0 g C m^(−2) year^(−1)).Sampling over a more extended period and continuous measurements are essential for determining the contribution of diferent lateral detrital C fux processes to closing the ecosystem C budgets.The sampling spatiotemporal granularities can be key to assessing lateral detrital C transfer.
文摘Objective To investigate the etiology,clinical features and outcome of hospitalized patients with bloodstream infections(BSIs)in a tertiary hospital.MethodsPositive blood cultures were obtained from the microbiological laboratory in Fuxing Hospital,Capital Medical University from January 1,2012 to December 31,2012.
