It is necessary for China to refocus its energy conservation effort from the industrial sector (field) to all three sectors simultaneously, i.e. industry, construction and transport. In addition, it should also make s...It is necessary for China to refocus its energy conservation effort from the industrial sector (field) to all three sectors simultaneously, i.e. industry, construction and transport. In addition, it should also make significant effort for conserving energy on general technical equipment that are used in large quantities and for a variety of applications. Therefore, there is a need to integrate industrial, construction and transport sectors, i.e. the integration between key technologies and widely used technologies, between hard and soft management, between energy-saving technologies and comprehensive resource utilization technologies. According to estimates, if China’s energy consuming sectors adopted appropriate energy-saving technologies, total energy-savings (using 2010 as the baseline) would be 200 million, 450 million, 650 million and 800 million tons of standard coal in 2015, 2020, 2025 and 2030, respectively.展开更多
Energy consumption for transport purposes has increased rapidly in China over the past decade. China’s transport industry has undergone remarkable developments in energy conservation through structural, technological...Energy consumption for transport purposes has increased rapidly in China over the past decade. China’s transport industry has undergone remarkable developments in energy conservation through structural, technological and managerial measures. The paper analyzes energy-conservation policies and measures related to road transport in China. The paper also identifies constraints for these policies and measures. The transport management authorities face a series of difficulties associated with methods, costs, public awareness, and management systems. Suggestions for improvement are also offered, including promotion of energy-efficient private vehicles, advances in business vehicle energy conservation, exploiting the energy potential of urban traffic and infrastructure development for energy-efficient clean vehicles.展开更多
Transportation is a sector with high energy consumption as well as high emissions.Generally speaking,economic growth will inevitably lead to the increase of travel demand and vehicle population,which in turn results i...Transportation is a sector with high energy consumption as well as high emissions.Generally speaking,economic growth will inevitably lead to the increase of travel demand and vehicle population,which in turn results into the augmentation of environmental and social costs.For metropolis like Beijing under rapid development,there exist various possibilities and options for transport development policy instruments.But there is no guarantee that they will be suitable for Beijing,although they are effective in their local places.This article assesses what kind of policy can most effectively improve the traffic conditions in Beijing in the future.After literature reviews on the practices of foreign policy and we established several feasible scenarios.Then,we used the Long Range Energy Alternatives Planning System(LREAP) analyzed their corresponding results of reduced energy consumption and emissions.Finally,by simulating and computing the realistic Beijing transportation scenarios,this paper scientifically assesses what kind of policy can most effectively improve the traffic condition in Beijing in the coming decade.展开更多
Aiming at optimizing the energy consumption of HVAC,an energy conservation optimization method was proposed for HVAC systems based on the sensitivity analysis(SA),named the sensitivity analysis combination method(SAC)...Aiming at optimizing the energy consumption of HVAC,an energy conservation optimization method was proposed for HVAC systems based on the sensitivity analysis(SA),named the sensitivity analysis combination method(SAC).Based on the SA,neural network and the related settings about energy conservation of HVAC systems,such as cooling water temperature,chilled water temperature and supply air temperature,were optimized.Moreover,based on the data of the existing HVAC system,various optimal control methods ofHVAC systems were tested and evaluated by a simulated HVAC system in TRNSYS.The results show that the proposed SA combination method can reduce significant computational load while maintaining an equivalent energy performance compared with traditional optimal control methods.展开更多
High density polyethylene (HDPE) samples, containing different concentrations of prodegradant additive d2w?, were prepared. The properties of the samples were evaluated through differential scanning calorimetry (DSC),...High density polyethylene (HDPE) samples, containing different concentrations of prodegradant additive d2w?, were prepared. The properties of the samples were evaluated through differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), rheometry, and scanning electron microscopy (SEM). The work contributes to decreasing the products made of non-biodegradable polymeric materials derived from fossil sources which are have become a problem due to their increasingly inappropriate disposal and long degradation time in the environment. The obtained results indicated that there was no degradation of the samples due to processing. No significant changes in melting temperature, crystallinity, viscoelastic behavior, molecular weight and chemical composition were observed. Images from SEM analysis showed particles on HDPE surface, attributed to prodegradant additive d2w?. Oxidation Onset Temperature (OOT) results showed that the additive d2w? accelerated the degradation of HDPE. The activation energy (Ea) was determined by Ozawa-Wall-Flynn method. The obtained values were used for lifetime estimation of the samples. At 25°C, HDPE with d2w? showed a lifetime 50% higher than that of HDPE without this additive. This fact is attributed to the presence of stabilizers in masterbatch d2w? and the absence of oxygen in thermogravimetric analysis.展开更多
Unconditionally stable higher-order accurate time step integration algorithms based on the differential quadrature method (DQM) for second-order initial value problems were applied and the quadrature rules of DQM, com...Unconditionally stable higher-order accurate time step integration algorithms based on the differential quadrature method (DQM) for second-order initial value problems were applied and the quadrature rules of DQM, computing of the weighting coefficients and choices of sampling grid points were discussed. Some numerical examples dealing with the heat transfer problem, the second-order differential equation of imposed vibration of linear single-degree-of-freedom systems and double-degree-of-freedom systems, the nonlinear move differential equation and a beam forced by a changing load were computed, respectively. The results indicated that the algorithm can produce highly accurate solutions with minimal time consumption, and that the system total energy can remain conservative in the numerical computation.展开更多
In this paper the authors discuss a numerical simulation problem of three-dimensional compressible contamination treatment from nuclear waste. The mathematical model, a nonlinear convection-diffusion system of four PD...In this paper the authors discuss a numerical simulation problem of three-dimensional compressible contamination treatment from nuclear waste. The mathematical model, a nonlinear convection-diffusion system of four PDEs, determines four major physical unknowns: the pressure, the concentrations of brine and radionuclide, and the temperature. The pressure is solved by a conservative mixed finite volume element method, and the computational accuracy is improved for Darcy velocity. Other unknowns are computed by a composite scheme of upwind approximation and mixed finite volume element. Numerical dispersion and nonphysical oscillation are eliminated, and the convection-dominated diffusion problems are solved well with high order computational accuracy. The mixed finite volume element is conservative locally, and get the objective functions and their adjoint vector functions simultaneously. The conservation nature is an important character in numerical simulation of underground fluid. Fractional step difference is introduced to solve the concentrations of radionuclide factors, and the computational work is shortened significantly by decomposing a three-dimensional problem into three successive one-dimensional problems. By the theory and technique of a priori estimates of differential equations, we derive an optimal order estimates in L2norm. Finally, numerical examples show the effectiveness and practicability for some actual problems.展开更多
Tasks in hard real-time systems are required to meet preset deadlines, even in the presence of transient faults and hence the analysis of worst-case finish time （WCFT） must consider the extra time incurred by re-exe...Tasks in hard real-time systems are required to meet preset deadlines, even in the presence of transient faults and hence the analysis of worst-case finish time （WCFT） must consider the extra time incurred by re-executing tasks that were faulty. Existing solutions can only estimate WCFT and usually result in significant under- or over-estimation. In this work, we conclude that a sufficient and necessary condition of a task set experiencing its WCFT is that its critical task incurs all expected transient faults. A method is presented to identify the critical task and WCFT in O（IVI ＋ IEI） where IVI and IEI are the number of tasks and dependencies between tasks, respectively. This method finds its application in testing the feasibility of directed acyclic graph （DAG） based task sets scheduled in a wide variety of fault-prone multi-processor systems, where the processors could be either homogeneous or heterogeneous, DVS-capable or DVS-incapable, etc. The common practices, which require the same time complexity as the proposed critical-task method, could either underestimate the worst case by up to 25%, or overestimate by 13%. Based on the proposed critical-task method, a simulated-annealing scheduling algorithm is developed to find the energy efficient fault-tolerant schedule for a given DAG task set. Experimental results show that the proposed critical-task method wins over a common practice by up to 40% in terms of energy saving.展开更多
A local energy conservation law is proposed for the Klein--Gordon-Schrrdinger equations, which is held in any local time-space region. The local property is independent of the boundary condition and more essential tha...A local energy conservation law is proposed for the Klein--Gordon-Schrrdinger equations, which is held in any local time-space region. The local property is independent of the boundary condition and more essential than the global energy conservation law. To develop a numerical method preserving the intrinsic properties as much as possible, we propose a local energy-preserving （LEP） scheme for the equations. The merit of the proposed scheme is that the local energy conservation law can hold exactly in any time-space region. With the periodic boundary conditions, the scheme also possesses the discrete change and global energy conservation laws. A nonlinear analysis shows that the LEP scheme converges to the exact solutions with order O（τ2 ＋ h2）. The theoretical properties are verified by numerical experiments.展开更多
In 2005, an innovative program was formed between the local government and The University of Toledo to help improve environmental and economic conditions in Lucas County, Ohio, USA by providing no cost energy assessme...In 2005, an innovative program was formed between the local government and The University of Toledo to help improve environmental and economic conditions in Lucas County, Ohio, USA by providing no cost energy assessments to various types of organizations. Unlike the Industrial Assessment Centers, which focus on manufacturing and are funded by the Federal Government, this program demonstrates that successful partnerships can be established at the local government level to aid various types of organizations in energy conservation and cost reduction. Since 2005, the program completed ten energy assessments and identified over 143,000 kwh and 103,000 kg of CO2 for reduction. Additionally, over $12,000 has been identified as annual cost savings for Lucas County businesses. The purpose of this paper is to provide a complete overview and framework of this program so that other institutions may learn from it and adopt similar programs at the local level. A focus of this paper is a discussion of a case study that details the process and results of a typical energy assessment conducted through the project and comparison to similar programs in the US.展开更多
文摘It is necessary for China to refocus its energy conservation effort from the industrial sector (field) to all three sectors simultaneously, i.e. industry, construction and transport. In addition, it should also make significant effort for conserving energy on general technical equipment that are used in large quantities and for a variety of applications. Therefore, there is a need to integrate industrial, construction and transport sectors, i.e. the integration between key technologies and widely used technologies, between hard and soft management, between energy-saving technologies and comprehensive resource utilization technologies. According to estimates, if China’s energy consuming sectors adopted appropriate energy-saving technologies, total energy-savings (using 2010 as the baseline) would be 200 million, 450 million, 650 million and 800 million tons of standard coal in 2015, 2020, 2025 and 2030, respectively.
文摘Energy consumption for transport purposes has increased rapidly in China over the past decade. China’s transport industry has undergone remarkable developments in energy conservation through structural, technological and managerial measures. The paper analyzes energy-conservation policies and measures related to road transport in China. The paper also identifies constraints for these policies and measures. The transport management authorities face a series of difficulties associated with methods, costs, public awareness, and management systems. Suggestions for improvement are also offered, including promotion of energy-efficient private vehicles, advances in business vehicle energy conservation, exploiting the energy potential of urban traffic and infrastructure development for energy-efficient clean vehicles.
文摘Transportation is a sector with high energy consumption as well as high emissions.Generally speaking,economic growth will inevitably lead to the increase of travel demand and vehicle population,which in turn results into the augmentation of environmental and social costs.For metropolis like Beijing under rapid development,there exist various possibilities and options for transport development policy instruments.But there is no guarantee that they will be suitable for Beijing,although they are effective in their local places.This article assesses what kind of policy can most effectively improve the traffic conditions in Beijing in the future.After literature reviews on the practices of foreign policy and we established several feasible scenarios.Then,we used the Long Range Energy Alternatives Planning System(LREAP) analyzed their corresponding results of reduced energy consumption and emissions.Finally,by simulating and computing the realistic Beijing transportation scenarios,this paper scientifically assesses what kind of policy can most effectively improve the traffic condition in Beijing in the coming decade.
基金supported by National Key R&D Program of China(No.2020YFC2006602)National Natural Science Foundation of China(Nos.62072324,61876217,61876121,61772357)+1 种基金University Natural Science Foundation of Jiangsu Province(No.21KJA520005)Primary Research and Development Plan of Jiangsu Province(No.BE2020026).
文摘Aiming at optimizing the energy consumption of HVAC,an energy conservation optimization method was proposed for HVAC systems based on the sensitivity analysis(SA),named the sensitivity analysis combination method(SAC).Based on the SA,neural network and the related settings about energy conservation of HVAC systems,such as cooling water temperature,chilled water temperature and supply air temperature,were optimized.Moreover,based on the data of the existing HVAC system,various optimal control methods ofHVAC systems were tested and evaluated by a simulated HVAC system in TRNSYS.The results show that the proposed SA combination method can reduce significant computational load while maintaining an equivalent energy performance compared with traditional optimal control methods.
文摘High density polyethylene (HDPE) samples, containing different concentrations of prodegradant additive d2w?, were prepared. The properties of the samples were evaluated through differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), rheometry, and scanning electron microscopy (SEM). The work contributes to decreasing the products made of non-biodegradable polymeric materials derived from fossil sources which are have become a problem due to their increasingly inappropriate disposal and long degradation time in the environment. The obtained results indicated that there was no degradation of the samples due to processing. No significant changes in melting temperature, crystallinity, viscoelastic behavior, molecular weight and chemical composition were observed. Images from SEM analysis showed particles on HDPE surface, attributed to prodegradant additive d2w?. Oxidation Onset Temperature (OOT) results showed that the additive d2w? accelerated the degradation of HDPE. The activation energy (Ea) was determined by Ozawa-Wall-Flynn method. The obtained values were used for lifetime estimation of the samples. At 25°C, HDPE with d2w? showed a lifetime 50% higher than that of HDPE without this additive. This fact is attributed to the presence of stabilizers in masterbatch d2w? and the absence of oxygen in thermogravimetric analysis.
文摘Unconditionally stable higher-order accurate time step integration algorithms based on the differential quadrature method (DQM) for second-order initial value problems were applied and the quadrature rules of DQM, computing of the weighting coefficients and choices of sampling grid points were discussed. Some numerical examples dealing with the heat transfer problem, the second-order differential equation of imposed vibration of linear single-degree-of-freedom systems and double-degree-of-freedom systems, the nonlinear move differential equation and a beam forced by a changing load were computed, respectively. The results indicated that the algorithm can produce highly accurate solutions with minimal time consumption, and that the system total energy can remain conservative in the numerical computation.
基金supported by the Natural Science Foundation of Shangdong Province (Grant No.ZR2021MA019)Natural Science Foundation of Hunan Province (Grant No.2018JJ2028)。
文摘In this paper the authors discuss a numerical simulation problem of three-dimensional compressible contamination treatment from nuclear waste. The mathematical model, a nonlinear convection-diffusion system of four PDEs, determines four major physical unknowns: the pressure, the concentrations of brine and radionuclide, and the temperature. The pressure is solved by a conservative mixed finite volume element method, and the computational accuracy is improved for Darcy velocity. Other unknowns are computed by a composite scheme of upwind approximation and mixed finite volume element. Numerical dispersion and nonphysical oscillation are eliminated, and the convection-dominated diffusion problems are solved well with high order computational accuracy. The mixed finite volume element is conservative locally, and get the objective functions and their adjoint vector functions simultaneously. The conservation nature is an important character in numerical simulation of underground fluid. Fractional step difference is introduced to solve the concentrations of radionuclide factors, and the computational work is shortened significantly by decomposing a three-dimensional problem into three successive one-dimensional problems. By the theory and technique of a priori estimates of differential equations, we derive an optimal order estimates in L2norm. Finally, numerical examples show the effectiveness and practicability for some actual problems.
基金This work is partially supported by the National High Technology Research and Development 863 Program of China under Grant Nos. 2015AA015304 and 2013AA013202, the National Natural Science Foundation of China under Grant No. 61472052, and Chongqing Research Program under Grant No. cstc2014yykfB40007.
文摘Tasks in hard real-time systems are required to meet preset deadlines, even in the presence of transient faults and hence the analysis of worst-case finish time （WCFT） must consider the extra time incurred by re-executing tasks that were faulty. Existing solutions can only estimate WCFT and usually result in significant under- or over-estimation. In this work, we conclude that a sufficient and necessary condition of a task set experiencing its WCFT is that its critical task incurs all expected transient faults. A method is presented to identify the critical task and WCFT in O（IVI ＋ IEI） where IVI and IEI are the number of tasks and dependencies between tasks, respectively. This method finds its application in testing the feasibility of directed acyclic graph （DAG） based task sets scheduled in a wide variety of fault-prone multi-processor systems, where the processors could be either homogeneous or heterogeneous, DVS-capable or DVS-incapable, etc. The common practices, which require the same time complexity as the proposed critical-task method, could either underestimate the worst case by up to 25%, or overestimate by 13%. Based on the proposed critical-task method, a simulated-annealing scheduling algorithm is developed to find the energy efficient fault-tolerant schedule for a given DAG task set. Experimental results show that the proposed critical-task method wins over a common practice by up to 40% in terms of energy saving.
基金supported by the National Natural Science Foundation of China(Grant Nos.11201169,11271195,and 41231173)the Project of Graduate Education Innovation of Jiangsu Province,China(Grant No.CXLX13 366)
文摘A local energy conservation law is proposed for the Klein--Gordon-Schrrdinger equations, which is held in any local time-space region. The local property is independent of the boundary condition and more essential than the global energy conservation law. To develop a numerical method preserving the intrinsic properties as much as possible, we propose a local energy-preserving （LEP） scheme for the equations. The merit of the proposed scheme is that the local energy conservation law can hold exactly in any time-space region. With the periodic boundary conditions, the scheme also possesses the discrete change and global energy conservation laws. A nonlinear analysis shows that the LEP scheme converges to the exact solutions with order O（τ2 ＋ h2）. The theoretical properties are verified by numerical experiments.
文摘In 2005, an innovative program was formed between the local government and The University of Toledo to help improve environmental and economic conditions in Lucas County, Ohio, USA by providing no cost energy assessments to various types of organizations. Unlike the Industrial Assessment Centers, which focus on manufacturing and are funded by the Federal Government, this program demonstrates that successful partnerships can be established at the local government level to aid various types of organizations in energy conservation and cost reduction. Since 2005, the program completed ten energy assessments and identified over 143,000 kwh and 103,000 kg of CO2 for reduction. Additionally, over $12,000 has been identified as annual cost savings for Lucas County businesses. The purpose of this paper is to provide a complete overview and framework of this program so that other institutions may learn from it and adopt similar programs at the local level. A focus of this paper is a discussion of a case study that details the process and results of a typical energy assessment conducted through the project and comparison to similar programs in the US.
