The classical job shop scheduling problem(JSP) is the most popular machine scheduling model in practice and is known as NP-hard.The formulation of the JSP is based on the assumption that for each part type or job ther...The classical job shop scheduling problem(JSP) is the most popular machine scheduling model in practice and is known as NP-hard.The formulation of the JSP is based on the assumption that for each part type or job there is only one process plan that prescribes the sequence of operations and the machine on which each operation has to be performed.However,JSP with alternative machines for various operations is an extension of the classical JSP,which allows an operation to be processed by any machine from a given set of machines.Since this problem requires an additional decision of machine allocation during scheduling,it is much more complex than JSP.We present a domain independent genetic algorithm(GA) approach for the job shop scheduling problem with alternative machines.The GA is implemented in a spreadsheet environment.The performance of the proposed GA is analyzed by comparing with various problem instances taken from the literatures.The result shows that the proposed GA is competitive with the existing approaches.A simplified approach that would be beneficial to both practitioners and researchers is presented for solving scheduling problems with alternative machines.展开更多
The problem of simultaneous scheduling of machines and vehicles in flexible manufacturing system (FMS) was addressed.A spreadsheet based genetic algorithm (GA) approach was presented to solve the problem.A domain inde...The problem of simultaneous scheduling of machines and vehicles in flexible manufacturing system (FMS) was addressed.A spreadsheet based genetic algorithm (GA) approach was presented to solve the problem.A domain independent general purpose GA was used,which was an add-in to the spreadsheet software.An adaptation of the propritary GA software was demonstrated to the problem of minimizing the total completion time or makespan for simultaneous scheduling of machines and vehicles in flexible manufacturing systems.Computational results are presented for a benchmark with 82 test problems,which have been constructed by other researchers.The achieved results are comparable to the previous approaches.The proposed approach can be also applied to other problems or objective functions without changing the GA routine or the spreadsheet model.展开更多
The electronic properties of sphalerite(110)surface bearing Fe,Mn and Cd impurities were calculated using density-functional theory,and the effects of impurities on the copper activation of sphalerite were investigate...The electronic properties of sphalerite(110)surface bearing Fe,Mn and Cd impurities were calculated using density-functional theory,and the effects of impurities on the copper activation of sphalerite were investigated.Calculated results indicate that both Fe and Mn impurities narrow the band gap of sphalerite surface and lead to the Fermi level shifting to conduction band.Impurity levels composed of Fe 3d and Mn 3d orbital appearing in band gap are beneficial to electrons transfer from the valence band to the conduction band and promote the surface conductivity and the electrochemical activity.The results show that Fe and Mn impurities cannot be replaced by Cu atom,which reduces the exchange sites(Zn)for Cu atom,hence Fe-and Mn-bearing sphalerites are hard to be activated by copper.Cd impurity has little effect on electronic structure of sphalerite surface;however,Cd atom is easily replaced by Cu atom,and this is the reason why the Cd-bearing sphalerite can be easily floated.展开更多
CeO2,Ce1–xZrxO2,and Ce1–xYxO2–δ(x=0.25,0.50,0.75,and 1.00)have been rapidly synthesized to estimate their catalytic behavior in decomposing CH3SH.The role of oxygen vacancies,and the relationship between the oxyge...CeO2,Ce1–xZrxO2,and Ce1–xYxO2–δ(x=0.25,0.50,0.75,and 1.00)have been rapidly synthesized to estimate their catalytic behavior in decomposing CH3SH.The role of oxygen vacancies,and the relationship between the oxygen species and catalytic properties of CeO2 and Zr‐doped and Y‐doped ceria‐based materials are investigated in detail.Combining the observed catalytic performance with the characterization results,it can be deemed that surface lattice oxygen plays a critical role in methanethiol catalytic conversion over cerium oxides.Ce0.75Zr0.25O2 shows higher catalytic activity for CH3SH decomposition due to the large amount of surface lattice oxygen,readily available oxygen species,and excellent redox properties.Ce0.75Y0.25O2–δdisplays better catalytic stability owing to the greater number of oxygen vacancies that would promote bulk lattice oxygen migration to the surface of the catalyst in order to replenish surface lattice oxygen.In addition,the results show that the difference in chemical valence between Ce and the heteroatoms would strongly influence the amount of surface lattice oxygen as well as the mobility of bulk‐phase oxygen in these catalysts,thus affecting their activity and stability.展开更多
According to the Total Cost of Ownership concept (TOCO), the selection criterion of international procurement suppliers can be classified into two levels, namely Macroeconomic decision-making level and Microeconomic d...According to the Total Cost of Ownership concept (TOCO), the selection criterion of international procurement suppliers can be classified into two levels, namely Macroeconomic decision-making level and Microeconomic decision-making level. In this paper, a new quantitative method is put forward to accomplish the task of total assessment on the Microeconomic level which analyses all of the quantitative and qualitative factors with regard to the supplier selection. A Microsoft Excel based new application kit named TOCO Total Assessment Tool is introduced. It can calculate the direct cost and the indirect cost conveniently and can help to evaluate the performance of candidate suppliers. To use the tool, the first module called Total Cost Analysis Module is introduced to calculate the total cost of supplier selection, and then the second module named Supplier Evaluation Module is used to evaluate the performance of each supplier. Finally, the results from these two modules are transferred to the Final Comparison Module to get the final decision-making results. In this paper, the supplier selection related factors are discussed; the method of using the tool is illustrated in detail. It is shown that scientific usage of the TOCO Total Assessment Tool can make the decision-making processes of supplier selection in international procurement transparent, easily calculated, and objective. At the end, a practical case is given to clarify the procedure of using the tool.展开更多
Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS (Geogr...Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS (Geographic Information System) software in GIS sector. However, those table data contain much unnecessary information that do not need for a certain project. Using the raw data can increase processing times and reduce performance of geoprocessing tools. This study shows steps of how the raw data are being processed using ArcGIS ModelBuilder and Python script.展开更多
In the current scenario of global competition and short product life cycles, customer-defined satisfaction has attracted interest in artifact design. Accordingly, intelligent decision-making through multi-objective op...In the current scenario of global competition and short product life cycles, customer-defined satisfaction has attracted interest in artifact design. Accordingly, intelligent decision-making through multi-objective optimization has been proposed as an efficient method for human-centered manufacturing. However, previous vast researches on optimization have been mainly focused on optimization theory and optimization techniques and paid little interests on the process of problem formulation itself. In this paper, therefore, the authors present a total framework for supporting multi-objective decision making. Then, the authors try to solve the formulated multi-objective optimization problem that involves both qualitative and quantitative performance measures as a general consequence from the above procedure. Taking especially quality as a qualitative measure, the authors gave a new idea to evaluate the quality quantitatively. Additionally, to facilitate the portability of the proposed method in multidisciplinary decision-making environments, the authors implement the proposal algorithm in an Excel spreadsheet and validate the effectiveness of the approach through a case study.展开更多
A simple and intuitive manner for solving fluid-structure interaction problem has been developed using Microsoft Excel spreadsheets. By eliminating the need of previous knowledge of any programming language, the metho...A simple and intuitive manner for solving fluid-structure interaction problem has been developed using Microsoft Excel spreadsheets. By eliminating the need of previous knowledge of any programming language, the method appears as an interesting introduction to numerical solutions of partial differential equations, due to the direct and didactic way that it is developed. Proposed procedure enables the analysis of tridimensional geometries using the finite difference method and can be extended to other differential equations or boundary conditions. The author's objective in this paper is to develop a simple and reliable preliminary method for solving acoustic fluid-structure interaction problems with application to dam-reservoir interaction phenomena and also contribute in the educational growth for undergraduate students that are beginning research in such matter.展开更多
By virtue of the technique of integration within an ordered product of operators we present a new formulation of the Weyl quantization scheme in the coherent state representation, which not only brings convenience for...By virtue of the technique of integration within an ordered product of operators we present a new formulation of the Weyl quantization scheme in the coherent state representation, which not only brings convenience for calculating the Weyl correspondence of normally ordered operators, but also directly leads us to find both the coherent state representation and the Weyl ordering representation of the Wigner operator.展开更多
The adsorption behavior of symmetric triblock copolymers, Am/2BnAm/2, from a nonselective solvent at solid-liquid interface has been studied by Monte Carlo simulations on a simple lattice model. Either segment A or se...The adsorption behavior of symmetric triblock copolymers, Am/2BnAm/2, from a nonselective solvent at solid-liquid interface has been studied by Monte Carlo simulations on a simple lattice model. Either segment A or segment B is attractive, while the other is non-attractive to the surface. Influences of the adsorption energy, bulk concentration, chain composition and chain length on the microstructure of adsorbed layers are presented. The results show that the total surface coverage and the adsorption amount increases monotonically as the bulk concentration increases. The larger the adsorption energy and the higher the fraction of adsorbing segments, the higher the total surface coverage is exhibited. The product of surface coverage and the proportion of non-attractive segments are nearly independent of the chain length, and the logarithm of the adsorption amount is a linear function of the reciprocal of the reduced temperature. When the adsorption energy is larger, the adsorption amount exhibits a maximum as the fraction of adsorbing segment increases. The adsorption isotherms of copolymers with different length of non-attractive segments can be mapped onto a single curve under given adsorption energy. The adsorption layer thickness decreases as the adsorption energy and the fraction of adsorbing segments increases, but it increases as the length of non-attractive segments increases. The tails mainly govern the adsorption layer thickness.展开更多
This paper presents the investigation of energy and cost saving of microgeneration systems which consist of conventional, load sharing, renewable energy and hybrid-renewable energy systems application featuring single...This paper presents the investigation of energy and cost saving of microgeneration systems which consist of conventional, load sharing, renewable energy and hybrid-renewable energy systems application featuring single detached house and office buildings by implementing spreadsheet modeling. Microsoft excel is employed as the spreadsheet application in this study. The system performance of each case is calculated under typical weather of ottawa, canada. These cases are calculated and analyzed in terms of thermal/cooling load (building demand) and natural gas/electricity consumption (energy supply) as well as the financial part by involving several parameters which are initial cost, annual energy consumption cost, annual operational and maintenance cost, inflation rate, and return on investment. Moreover, a house and an office have the same geometry of 200 mE. Total of seven cases modeling are developed; Case-1- a house with boiler and chiller, Case-2- an office with boiler and chiller, Case-3-a simple sum of Case l and Case 2, Case-4- a load-sharing model, Case-5- a load-sharing with GSHP (ground source heat pump), Case-6- a load-sharing with ground source heat pump-fuel cell hybrid system (FC-GSHP)and Case-7- a load-sharing with GSHP--photovoltaic hybrid system (PVT-GSHP). As the results, it will be observed the efficiency of the load-sharing, renewable energy, hybrid-renewable energy implementation comparing to the conventional system.展开更多
A 3-dimensional Lie algebra sμ(3) is obtained with the help of the known Lie algebra. Based on the sμ(3), a new discrete 3 × 3 matrix spectral problem with three potentials is constructed. In virtue of disc...A 3-dimensional Lie algebra sμ(3) is obtained with the help of the known Lie algebra. Based on the sμ(3), a new discrete 3 × 3 matrix spectral problem with three potentials is constructed. In virtue of discrete zero curvature equations, a new matrix Lax representation for the hierarchy of the discrete lattice soliton equations is acquired. It is shown that the hierarchy possesses a Hamiltonian operator and a hereditary recursion operator, which implies that there exist infinitely many common commuting symmetries and infinitely many common commuting conserved functionals.展开更多
We study theoretically the quantum effects of the littlest Higgs model (LH) mediated by flavor changing one-loop Feynman diagrams on the rare decay process t → cH0. The comparison of the decay width in the LH model w...We study theoretically the quantum effects of the littlest Higgs model (LH) mediated by flavor changing one-loop Feynman diagrams on the rare decay process t → cH0. The comparison of the decay width in the LH model with that in the standard model (SM) is made. We find that the decay branch ratio of t → cH0 in the LH model is at most of the order ~ 10-12, which is two order larger than in the SM. The numerical results show that the difference between the branch ratios in the LH model and the SM is generally sensitive to the LH model parameters, such as symmetry breaking scale f, Higgs boson mass mH0, and x = v'4f /v2 in our chosen parameter space, but relatively insensitive to the value choice of the cosine of the mixing angle c and the ratio λ1/λ2.展开更多
Smoothed particle hydrodynamics (SPH) is a Lagrangian meshless particle method. It is one of the best method for simulating violent free surface flows in fluids and solving large fluid deformations. Dam breaking is a ...Smoothed particle hydrodynamics (SPH) is a Lagrangian meshless particle method. It is one of the best method for simulating violent free surface flows in fluids and solving large fluid deformations. Dam breaking is a typical example of these problems. The basis of SPH was reviewed, including some techniques for governing equation resolution, such as the stepping method and the boundary handling method. Then numerical results of a dam breaking simulation were discussed, and the benefits of concepts like artificial viscosity and position correction were analyzed in detail. When compared with dam breaking simulated by the volume of fluid (VOF) method, the wave profile generated by SPH had good agreement, but the pressure had only reasonable agreement. Improving pressure results is clearly an important next step for research.展开更多
A new model is proposed to explain the physical mechanism of the extraordinary transmission enhancement in subwavelength metallic grating.The extraordinary transmission enhancement is described by the co-operation of ...A new model is proposed to explain the physical mechanism of the extraordinary transmission enhancement in subwavelength metallic grating.The extraordinary transmission enhancement is described by the co-operation of Fabry-Perot-like(FPL) resonance and the surface plasmon polariton(SPP) resonance.The rigorous coupled-wave analysis(RCWA) and the finite difference time domain(FDTD) method are employed to illustrate the model by calculating the transmission and the field distributions in the subwavelength metallic grating,respectively.And the numerical calculations show that transmission enhancement is achieved when the coupling resonance of the incident light,the surface plasmon polariton mode and the Fabry-Perot-Like mode is happened,which are in good agreement with the proposed model.展开更多
Traditional light bulbs (e.g., incandescent, fluorescent) use too much electricity, convert very little energy into light of sufficient quality and in their production use toxic contaminants. During the last few yea...Traditional light bulbs (e.g., incandescent, fluorescent) use too much electricity, convert very little energy into light of sufficient quality and in their production use toxic contaminants. During the last few years, a new type of light source, LED (light emitting diode) bulb, has gained increasing popularity and its costs are set to plunge even further. LED bulbs offer many advantages over traditional sources, and they can be used as a direct replacement to existing lighting. This paper will use a spreadsheet-based analysis with hourly solar data supplied by Ecotect to show that, the efficiency of LED installations can be increased when used in conjunction with photovoltaic modules, as the two generate (and use) DC (direct-current) electricity, thereby eliminating intermediate-level losses in the electronic circuitry. If a storage battery is included, the solar panels generate electricity during the times when the occupants are not necessarily using the lighting, but the stored electricity can be used to power the lighting when the energy is required. The latest results demonstrate that, a slight reduction in the required floor area to be lit allows the solar-battery-LED system to be implemented in small buildings using a storage battery size that is within the range of present commercial devices.展开更多
This paper deals with the problem of tunneling effects on existing buildings. The direct solution,using the condensation method,is presented. This method allows the structural and geotechnical engineers to treat the p...This paper deals with the problem of tunneling effects on existing buildings. The direct solution,using the condensation method,is presented. This method allows the structural and geotechnical engineers to treat the problem separately and then assemble a relatively small matrix that can be solved directly,even within a spreadsheet. There are certain concerns that the resultant matrix may be ill-conditioned when the structure is very stiff. This paper suggests an alternative method that essentially relaxes the system from an infinitely rigid structure solution. As such,it does not encounter the problems associated with stiff systems. The two methods are evaluated for an example problem of tunneling below a framed structure. It is found that while the direct method may fail to predict reasonable values when the structure is extremely rigid,the alternative method is stable. The relaxation method can therefore be used in cases where there are concerns about the reliability of a direct solution.展开更多
Due to the property of water repellence, biomimetic superhydrophobic surfaces have been widely applied to green technologies, in turn inducing wider and deeper investigations on superhydrophobic surfaces. Theoretical,...Due to the property of water repellence, biomimetic superhydrophobic surfaces have been widely applied to green technologies, in turn inducing wider and deeper investigations on superhydrophobic surfaces. Theoretical, experimental and numerical studies on wetting transitions have been carried out by researchers, but the mechanism of wetting transitions between Cassie-Baxter state and Wenzel state, which is crucial to develop a stable superhydrophobic surface, is still not fully understood. In this paper, the flee energy curves based on the transition processes are presented and discussed in detail. The exis- tence of energy barriers with or without consideration of the gravity effect, and the irreversibility of wet- ting transition are discussed based on the presented energy curves. The energy curves show that different routes of the Cassie-to-Wenzel transition and the reverse transition are the main reason for the irre- versibility. Numerical simulations are implemented via a phase field lattice Boltzmann method of large density ratio, and the simulation results show good consistency with the theoretical analysis.展开更多
文摘The classical job shop scheduling problem(JSP) is the most popular machine scheduling model in practice and is known as NP-hard.The formulation of the JSP is based on the assumption that for each part type or job there is only one process plan that prescribes the sequence of operations and the machine on which each operation has to be performed.However,JSP with alternative machines for various operations is an extension of the classical JSP,which allows an operation to be processed by any machine from a given set of machines.Since this problem requires an additional decision of machine allocation during scheduling,it is much more complex than JSP.We present a domain independent genetic algorithm(GA) approach for the job shop scheduling problem with alternative machines.The GA is implemented in a spreadsheet environment.The performance of the proposed GA is analyzed by comparing with various problem instances taken from the literatures.The result shows that the proposed GA is competitive with the existing approaches.A simplified approach that would be beneficial to both practitioners and researchers is presented for solving scheduling problems with alternative machines.
文摘The problem of simultaneous scheduling of machines and vehicles in flexible manufacturing system (FMS) was addressed.A spreadsheet based genetic algorithm (GA) approach was presented to solve the problem.A domain independent general purpose GA was used,which was an add-in to the spreadsheet software.An adaptation of the propritary GA software was demonstrated to the problem of minimizing the total completion time or makespan for simultaneous scheduling of machines and vehicles in flexible manufacturing systems.Computational results are presented for a benchmark with 82 test problems,which have been constructed by other researchers.The achieved results are comparable to the previous approaches.The proposed approach can be also applied to other problems or objective functions without changing the GA routine or the spreadsheet model.
基金Project(50864001) supported by the National Natural Science Foundation of China
文摘The electronic properties of sphalerite(110)surface bearing Fe,Mn and Cd impurities were calculated using density-functional theory,and the effects of impurities on the copper activation of sphalerite were investigated.Calculated results indicate that both Fe and Mn impurities narrow the band gap of sphalerite surface and lead to the Fermi level shifting to conduction band.Impurity levels composed of Fe 3d and Mn 3d orbital appearing in band gap are beneficial to electrons transfer from the valence band to the conduction band and promote the surface conductivity and the electrochemical activity.The results show that Fe and Mn impurities cannot be replaced by Cu atom,which reduces the exchange sites(Zn)for Cu atom,hence Fe-and Mn-bearing sphalerites are hard to be activated by copper.Cd impurity has little effect on electronic structure of sphalerite surface;however,Cd atom is easily replaced by Cu atom,and this is the reason why the Cd-bearing sphalerite can be easily floated.
基金supported by the National Natural Science Foundation of China (21667016, 21267011, U1402233)~~
文摘CeO2,Ce1–xZrxO2,and Ce1–xYxO2–δ(x=0.25,0.50,0.75,and 1.00)have been rapidly synthesized to estimate their catalytic behavior in decomposing CH3SH.The role of oxygen vacancies,and the relationship between the oxygen species and catalytic properties of CeO2 and Zr‐doped and Y‐doped ceria‐based materials are investigated in detail.Combining the observed catalytic performance with the characterization results,it can be deemed that surface lattice oxygen plays a critical role in methanethiol catalytic conversion over cerium oxides.Ce0.75Zr0.25O2 shows higher catalytic activity for CH3SH decomposition due to the large amount of surface lattice oxygen,readily available oxygen species,and excellent redox properties.Ce0.75Y0.25O2–δdisplays better catalytic stability owing to the greater number of oxygen vacancies that would promote bulk lattice oxygen migration to the surface of the catalyst in order to replenish surface lattice oxygen.In addition,the results show that the difference in chemical valence between Ce and the heteroatoms would strongly influence the amount of surface lattice oxygen as well as the mobility of bulk‐phase oxygen in these catalysts,thus affecting their activity and stability.
文摘According to the Total Cost of Ownership concept (TOCO), the selection criterion of international procurement suppliers can be classified into two levels, namely Macroeconomic decision-making level and Microeconomic decision-making level. In this paper, a new quantitative method is put forward to accomplish the task of total assessment on the Microeconomic level which analyses all of the quantitative and qualitative factors with regard to the supplier selection. A Microsoft Excel based new application kit named TOCO Total Assessment Tool is introduced. It can calculate the direct cost and the indirect cost conveniently and can help to evaluate the performance of candidate suppliers. To use the tool, the first module called Total Cost Analysis Module is introduced to calculate the total cost of supplier selection, and then the second module named Supplier Evaluation Module is used to evaluate the performance of each supplier. Finally, the results from these two modules are transferred to the Final Comparison Module to get the final decision-making results. In this paper, the supplier selection related factors are discussed; the method of using the tool is illustrated in detail. It is shown that scientific usage of the TOCO Total Assessment Tool can make the decision-making processes of supplier selection in international procurement transparent, easily calculated, and objective. At the end, a practical case is given to clarify the procedure of using the tool.
文摘Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS (Geographic Information System) software in GIS sector. However, those table data contain much unnecessary information that do not need for a certain project. Using the raw data can increase processing times and reduce performance of geoprocessing tools. This study shows steps of how the raw data are being processed using ArcGIS ModelBuilder and Python script.
文摘In the current scenario of global competition and short product life cycles, customer-defined satisfaction has attracted interest in artifact design. Accordingly, intelligent decision-making through multi-objective optimization has been proposed as an efficient method for human-centered manufacturing. However, previous vast researches on optimization have been mainly focused on optimization theory and optimization techniques and paid little interests on the process of problem formulation itself. In this paper, therefore, the authors present a total framework for supporting multi-objective decision making. Then, the authors try to solve the formulated multi-objective optimization problem that involves both qualitative and quantitative performance measures as a general consequence from the above procedure. Taking especially quality as a qualitative measure, the authors gave a new idea to evaluate the quality quantitatively. Additionally, to facilitate the portability of the proposed method in multidisciplinary decision-making environments, the authors implement the proposal algorithm in an Excel spreadsheet and validate the effectiveness of the approach through a case study.
文摘A simple and intuitive manner for solving fluid-structure interaction problem has been developed using Microsoft Excel spreadsheets. By eliminating the need of previous knowledge of any programming language, the method appears as an interesting introduction to numerical solutions of partial differential equations, due to the direct and didactic way that it is developed. Proposed procedure enables the analysis of tridimensional geometries using the finite difference method and can be extended to other differential equations or boundary conditions. The author's objective in this paper is to develop a simple and reliable preliminary method for solving acoustic fluid-structure interaction problems with application to dam-reservoir interaction phenomena and also contribute in the educational growth for undergraduate students that are beginning research in such matter.
基金Supported by the National Natural Science Foundation of China under Grant No.10775097
文摘By virtue of the technique of integration within an ordered product of operators we present a new formulation of the Weyl quantization scheme in the coherent state representation, which not only brings convenience for calculating the Weyl correspondence of normally ordered operators, but also directly leads us to find both the coherent state representation and the Weyl ordering representation of the Wigner operator.
基金the National Natural Science Foundation of China (No. 20025618, No. 20236010) Shanghai Municipal Education Commission of China.
文摘The adsorption behavior of symmetric triblock copolymers, Am/2BnAm/2, from a nonselective solvent at solid-liquid interface has been studied by Monte Carlo simulations on a simple lattice model. Either segment A or segment B is attractive, while the other is non-attractive to the surface. Influences of the adsorption energy, bulk concentration, chain composition and chain length on the microstructure of adsorbed layers are presented. The results show that the total surface coverage and the adsorption amount increases monotonically as the bulk concentration increases. The larger the adsorption energy and the higher the fraction of adsorbing segments, the higher the total surface coverage is exhibited. The product of surface coverage and the proportion of non-attractive segments are nearly independent of the chain length, and the logarithm of the adsorption amount is a linear function of the reciprocal of the reduced temperature. When the adsorption energy is larger, the adsorption amount exhibits a maximum as the fraction of adsorbing segment increases. The adsorption isotherms of copolymers with different length of non-attractive segments can be mapped onto a single curve under given adsorption energy. The adsorption layer thickness decreases as the adsorption energy and the fraction of adsorbing segments increases, but it increases as the length of non-attractive segments increases. The tails mainly govern the adsorption layer thickness.
文摘This paper presents the investigation of energy and cost saving of microgeneration systems which consist of conventional, load sharing, renewable energy and hybrid-renewable energy systems application featuring single detached house and office buildings by implementing spreadsheet modeling. Microsoft excel is employed as the spreadsheet application in this study. The system performance of each case is calculated under typical weather of ottawa, canada. These cases are calculated and analyzed in terms of thermal/cooling load (building demand) and natural gas/electricity consumption (energy supply) as well as the financial part by involving several parameters which are initial cost, annual energy consumption cost, annual operational and maintenance cost, inflation rate, and return on investment. Moreover, a house and an office have the same geometry of 200 mE. Total of seven cases modeling are developed; Case-1- a house with boiler and chiller, Case-2- an office with boiler and chiller, Case-3-a simple sum of Case l and Case 2, Case-4- a load-sharing model, Case-5- a load-sharing with GSHP (ground source heat pump), Case-6- a load-sharing with ground source heat pump-fuel cell hybrid system (FC-GSHP)and Case-7- a load-sharing with GSHP--photovoltaic hybrid system (PVT-GSHP). As the results, it will be observed the efficiency of the load-sharing, renewable energy, hybrid-renewable energy implementation comparing to the conventional system.
基金Supported by the Science and Technology Plan project of the Educational Department of Shandong Province of China under Grant No. J09LA54the research project of "SUST Spring Bud" of Shandong university of science and technology of China under Grant No. 2009AZZ071
文摘A 3-dimensional Lie algebra sμ(3) is obtained with the help of the known Lie algebra. Based on the sμ(3), a new discrete 3 × 3 matrix spectral problem with three potentials is constructed. In virtue of discrete zero curvature equations, a new matrix Lax representation for the hierarchy of the discrete lattice soliton equations is acquired. It is shown that the hierarchy possesses a Hamiltonian operator and a hereditary recursion operator, which implies that there exist infinitely many common commuting symmetries and infinitely many common commuting conserved functionals.
文摘We study theoretically the quantum effects of the littlest Higgs model (LH) mediated by flavor changing one-loop Feynman diagrams on the rare decay process t → cH0. The comparison of the decay width in the LH model with that in the standard model (SM) is made. We find that the decay branch ratio of t → cH0 in the LH model is at most of the order ~ 10-12, which is two order larger than in the SM. The numerical results show that the difference between the branch ratios in the LH model and the SM is generally sensitive to the LH model parameters, such as symmetry breaking scale f, Higgs boson mass mH0, and x = v'4f /v2 in our chosen parameter space, but relatively insensitive to the value choice of the cosine of the mixing angle c and the ratio λ1/λ2.
基金Supported by the National Natural Science Foundation of China under Grant No. 10572041 and 50779008
文摘Smoothed particle hydrodynamics (SPH) is a Lagrangian meshless particle method. It is one of the best method for simulating violent free surface flows in fluids and solving large fluid deformations. Dam breaking is a typical example of these problems. The basis of SPH was reviewed, including some techniques for governing equation resolution, such as the stepping method and the boundary handling method. Then numerical results of a dam breaking simulation were discussed, and the benefits of concepts like artificial viscosity and position correction were analyzed in detail. When compared with dam breaking simulated by the volume of fluid (VOF) method, the wave profile generated by SPH had good agreement, but the pressure had only reasonable agreement. Improving pressure results is clearly an important next step for research.
基金Supported by the National Natural Science Foundation of China under Grant Nos.60977048 and 61078046the International Collaboration Program of Ningbo under Grant No.2010D10018the International Joint Projects CNR/CAS Agreement and the K.C.Wong Magna Fund in Ningbo University,China
文摘A new model is proposed to explain the physical mechanism of the extraordinary transmission enhancement in subwavelength metallic grating.The extraordinary transmission enhancement is described by the co-operation of Fabry-Perot-like(FPL) resonance and the surface plasmon polariton(SPP) resonance.The rigorous coupled-wave analysis(RCWA) and the finite difference time domain(FDTD) method are employed to illustrate the model by calculating the transmission and the field distributions in the subwavelength metallic grating,respectively.And the numerical calculations show that transmission enhancement is achieved when the coupling resonance of the incident light,the surface plasmon polariton mode and the Fabry-Perot-Like mode is happened,which are in good agreement with the proposed model.
文摘Traditional light bulbs (e.g., incandescent, fluorescent) use too much electricity, convert very little energy into light of sufficient quality and in their production use toxic contaminants. During the last few years, a new type of light source, LED (light emitting diode) bulb, has gained increasing popularity and its costs are set to plunge even further. LED bulbs offer many advantages over traditional sources, and they can be used as a direct replacement to existing lighting. This paper will use a spreadsheet-based analysis with hourly solar data supplied by Ecotect to show that, the efficiency of LED installations can be increased when used in conjunction with photovoltaic modules, as the two generate (and use) DC (direct-current) electricity, thereby eliminating intermediate-level losses in the electronic circuitry. If a storage battery is included, the solar panels generate electricity during the times when the occupants are not necessarily using the lighting, but the stored electricity can be used to power the lighting when the energy is required. The latest results demonstrate that, a slight reduction in the required floor area to be lit allows the solar-battery-LED system to be implemented in small buildings using a storage battery size that is within the range of present commercial devices.
基金supported by the Israel Ministry of Housing and Construction, through the National Building Research Institute at the Technion-Israel Institute of Technology, Israel
文摘This paper deals with the problem of tunneling effects on existing buildings. The direct solution,using the condensation method,is presented. This method allows the structural and geotechnical engineers to treat the problem separately and then assemble a relatively small matrix that can be solved directly,even within a spreadsheet. There are certain concerns that the resultant matrix may be ill-conditioned when the structure is very stiff. This paper suggests an alternative method that essentially relaxes the system from an infinitely rigid structure solution. As such,it does not encounter the problems associated with stiff systems. The two methods are evaluated for an example problem of tunneling below a framed structure. It is found that while the direct method may fail to predict reasonable values when the structure is extremely rigid,the alternative method is stable. The relaxation method can therefore be used in cases where there are concerns about the reliability of a direct solution.
基金financial support of this work by the doctoral degree scholarship of China Scholarship Council and the University of Nottingham,UK
文摘Due to the property of water repellence, biomimetic superhydrophobic surfaces have been widely applied to green technologies, in turn inducing wider and deeper investigations on superhydrophobic surfaces. Theoretical, experimental and numerical studies on wetting transitions have been carried out by researchers, but the mechanism of wetting transitions between Cassie-Baxter state and Wenzel state, which is crucial to develop a stable superhydrophobic surface, is still not fully understood. In this paper, the flee energy curves based on the transition processes are presented and discussed in detail. The exis- tence of energy barriers with or without consideration of the gravity effect, and the irreversibility of wet- ting transition are discussed based on the presented energy curves. The energy curves show that different routes of the Cassie-to-Wenzel transition and the reverse transition are the main reason for the irre- versibility. Numerical simulations are implemented via a phase field lattice Boltzmann method of large density ratio, and the simulation results show good consistency with the theoretical analysis.