From Kaula's Earth gravitational potential written in classical orbital elements, the unified ideal model of mean motion resonance of artificial satellites due to geopotential perturbations is developed in this pa...From Kaula's Earth gravitational potential written in classical orbital elements, the unified ideal model of mean motion resonance of artificial satellites due to geopotential perturbations is developed in this paper first, through a suitable sequence of canonical transformations constructed by implicit functions. This unified ideal orbital resonance model is valid for all the commensurabilities between the rotational angular velocity of the Earth and the angular velocities of mean orbital motion of artificial satellites with arbitrary inclination and small eccentricity, and can be also transformed into Garfinkel's general expression of ideal resonance problem. Then 1/1 resonance of the 24-hour satellite with arbitrary inclination and small eccentricity is analyzed under the effect of harmonics of J2 and J 22 of the geopotential, based on the unified ideal model of mean motion resonance. The analytical expressions of the libration period and libration half width of the 1/1 resonance of the 24-hour satellite with arbitrary inclination and small eccentricity are presented.展开更多
If there is no imagination, there is no music appreciation. It should create imaginary world for students in the music classroom teaching practice, and it should foster the students＇ musical imagination. Thus, collea...If there is no imagination, there is no music appreciation. It should create imaginary world for students in the music classroom teaching practice, and it should foster the students＇ musical imagination. Thus, colleagues can make discussion about strategies proposed including pilot background, context led, screen hygiene conditions and others. We use Cognitive Linguistic Theories to introduce idealized cognitive model and its theoretical basis and the intensified impact on student musical imagination.展开更多
In the article a molecular model of oil with nanoparticles on the basis of the model of ideal fluid is considered. It is assumed that the molecular model of the oil can be represented as a homogenous distribution of i...In the article a molecular model of oil with nanoparticles on the basis of the model of ideal fluid is considered. It is assumed that the molecular model of the oil can be represented as a homogenous distribution of identical molecules in space. It is assumed that the central interaction between the oil molecules and nanoparticles, results in a change of the model parameters. It is shown that for an ideal fluid the effect of nanoparticles is reduced to a change of the coefficient at the pressure.展开更多
By comparing China's import of major imported agriculture textile material( cotton and wool),the characteristics of import are concluded. On this basis,a restricted version of source differentiated almost ideal de...By comparing China's import of major imported agriculture textile material( cotton and wool),the characteristics of import are concluded. On this basis,a restricted version of source differentiated almost ideal demand system( RSDAIDS) is used to estimate the income and price elasticity of major imported agriculture textile material from the major sources based on the data from 1992 to 2015. The results are shown as follows.( 1) Although the dependency on imported cotton is lower than wool, the fluctuation of cotton import is much more drastic; China's demand for cotton is relatively price elastic with higher expenditure elasticity compared with wool; besides,the existence of complementarity is proved between imported cotton and wool.( 2) According to the import elasticity of cotton,demand for cotton imported from India shows priority over cotton from other sources; demand for cotton imported from America is the most price-sensitive one; substitution among cotton from different sources is weak.( 3) According to the import elasticity of wool,wool imported from Uruguay has bright market prospects. In addition,wool imported from Australia has irreplaceable advantage than that from New Zealand.展开更多
Knowledge about the amino acid requirements and the response of pigs to the amino acid supply is essential in feed formulation. A deficient AA supply results in a reduction in performance while an oversupply is costly...Knowledge about the amino acid requirements and the response of pigs to the amino acid supply is essential in feed formulation. A deficient AA supply results in a reduction in performance while an oversupply is costly and leads to excessive nitrogen excretion with a potentially negative environmental impact. Amino acid requirements are determined to a large extent by the protein deposition in the body and, for lactating sows, by the protein exported in the milk. The concept of ideal protein was developed more than 50 years ago and refers to a protein with an amino acid profile that exactly meets the animal＇s requirement so that all amino acids are equally limiting for performance. Because Lys typically is the first-limiting amino acid, the ideal amino acid profile is often expressed relative to Lys. Although the ideal protein profile is often assumed to be constant for a given production stage, （small） changes in the ideal protein profile can occur within a production stage. This can be caused by changes in the relative contribution of the different components of amino acid requirements during the productive life on the animal （e.g. changes in the relative contribution of growth and maintenance）. Amino acids requirements can be determined experimentally using dose-response studies. The design of the study, the chosen response criterion, and the statistical model affect the requirement estimate. Although considerable experimental work has been carried out to determine the requirements for Lys, Met, Thr, and Trp in growing pigs （and to a lesser extent in sows）, little is known about the requirements for the other essential amino acids. Experimental dose-response studies generally focus on the requirement and less on the overall response （i.e. what are the consequences of an amino acid deficiency？）. This latter aspect is, to some extent, accounted for in modelling approaches that quantify the response of the animal to the amino acid supply in a dynamic way. The paper describes the origin of ideal protein and illustrates how fundamental concepts of amino acid nutrition have been integrated in practical modeling approaches for the nutrition of growing pigs and sows.展开更多
This paper described the main four basic models of ideal landscape in the Mount Lushan National Park as Kunlunshan model, Xumishan model, Peach flower land model, Christian model. Five typical places in Mount Lushan w...This paper described the main four basic models of ideal landscape in the Mount Lushan National Park as Kunlunshan model, Xumishan model, Peach flower land model, Christian model. Five typical places in Mount Lushan with the ideal landscape characteristics like the East Grove Temple, White Deer Cave Academy, Simplicity and Tranquility Monastery, Lushan Valley, and Villa-cluster of the East Valley were analyzed, and the integration of the basic models for each place was discussed to make the realistic landscape conform to the ideal needs. Moreover, the discussions also involved the characteristics of ideal landscape that are featured in resource, culture, structure, function, process, scale and region. In conclusion, ideal landscape in the Mount Lushan National Park was the product of the interaction between human and nature. Mount Lushan inherits the essence of Chinese traditional culture with a history of more than 1000 years; and it also absorbs the manna of the Western culture as well as the exchanges between nature and humanities together with the conflict and adaptation among different cultures. The natural landscape could be satisfied with the survival demand and cultural taste of mankind by the way of ecological planning.展开更多
In this paper hybrid converters with double inputs are investigated. Mainly any possible topologies are constructed and only one of them is chosen and modeled in none ideal format, by state space averaging method. Aft...In this paper hybrid converters with double inputs are investigated. Mainly any possible topologies are constructed and only one of them is chosen and modeled in none ideal format, by state space averaging method. After that small signal model and equilibrium point of that model is calculated. Finally with power sharing analysis the best point in efficiency was calculated.展开更多
The ideal reaction chromatography model can be regarded as a semi-coupled system of two hyperbolic partial differential equations,in which,one is a self-closed nonlinear equation for the reactant concentration and ano...The ideal reaction chromatography model can be regarded as a semi-coupled system of two hyperbolic partial differential equations,in which,one is a self-closed nonlinear equation for the reactant concentration and another is a linear equation coupling the reactant concentration for the resultant concentration.This paper is concerned with the initial-boundary value problem for the above model.By the characteristic method and the truncation method,we construct the global weak entropy solution of this initial initial-boundary value problem for Riemann type of initial-boundary data.Moreover,as examples,we apply the obtained results to the cases of head-on and wide pulse injections and give the expression of the global weak entropy solution.展开更多
From the analysis of helical characteristics, ideal geometric models of cutting edge and helical groove of nose burr are developed to realize the ideal geometric model of helical groove of nose burr, in terms of not o...From the analysis of helical characteristics, ideal geometric models of cutting edge and helical groove of nose burr are developed to realize the ideal geometric model of helical groove of nose burr, in terms of not only the shape of cutting edge being accurately machined but also rake angle and depth of groove in fall compliance with design requirements. The fundamental relationship of too-groove engagment for groove shaping and the complex formulas related are verified by the example of machining and its computer simulation.展开更多
A new method of robust damper design is presented for elastic-plastic multi-degree-of-freedom(MDOF)building structures under multi-level ground motions(GMs).This method realizes a design that is effective for various ...A new method of robust damper design is presented for elastic-plastic multi-degree-of-freedom(MDOF)building structures under multi-level ground motions(GMs).This method realizes a design that is effective for various levels of GMs.The robustness of a design is measured by an incremental dynamic analysis(IDA)curve and an ideal drift response curve(IDRC).The IDRC is a plot of the optimized maximum deformation under a constraint on the total damper quantity vs.the design level of the GMs.The total damper quantity corresponds to the total cost of the added dampers.First,a problem of generation of IDRCs is stated.Then,its solution algorithm,which consists of the sensitivity-based algorithm(SBA)and a local search method,is proposed.In the application of the SBA,the passive added dampers are removed sequentially under the specified-level GMs.On the other hand,the proposed local search method can search the optimal solutions for a constant total damper quantity under GMs’increased levels.In this way,combining these two algorithms enables the comprehensive search of the optimal solutions for various conditions of the status of the GMs and the total damper quantity.The influence of selecting the type of added dampers(oil,hysteretic,and so on)and the selection of the input GMs on the IDRCs are investigated.Finally,a robust optimal design problem is formulated,and a simple local search-based algorithm is proposed.A simple index using the IDRC and the IDA curve of the model is used as the objective function.It is demonstrated that the proposed algorithm works well in spite of its simplicity.展开更多
A single diode model for a photovoltaic solar module is the most ideal and quick way of analyzing the module characteristics before implementing them in a solar plant. Solar modules manufacturers provide information f...A single diode model for a photovoltaic solar module is the most ideal and quick way of analyzing the module characteristics before implementing them in a solar plant. Solar modules manufacturers provide information for three critical points that are essential in I-V, P-V or P-I curves. In this study, we propose four separate simulation procedures to estimate the five-model parameters of an analogous single diode equivalent circuit by utilizing three cardinal points of the photovoltaic module I-V curve, described from experimental data using a solar simulator and manufacturer’s datasheet. The main objective is to extract and use the five unknown parameters of a single diode model to describe the photovoltaic system using I-V ad P-V plots under different environmental conditions. The most influential parameters that greatly alter the cardinal points defined at short circuit point (SCP), the maximum power point (MPP) and the open circuit point(OCP) are the ideality factor (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;">) and the diode saturation current (</span><i><span style="font-family:Verdana;">I<sub>o</sub></span></i><span style="font-family:Verdana;">). For a quick and fast convergence, we have determined the optimal ideality factor (</span><i><span style="font-family:Verdana;">n<sub>o</sub></span></i><span style="font-family:Verdana;">) and optimal saturation current (</span><i><span style="font-family:Verdana;">I<sub>oopt</sub></span></i><span style="font-family:Verdana;">) as the primary parameters by first assuming the optimal values of </span><i><span style="font-family:Verdana;">R<sub>sh</sub></span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">R<sub>s</sub> </span></i><span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">I<sub>ph</sub> </span></i><span style="font-family:Verdana;">at standard test conditions (STC). Further, we evaluated the effects of </span><i><span style="font-family:Verdana;">I<sub>ph</sub></span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">R<sub>s</sub> </span></i><span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">R<sub>sh</sub> </span></i><span style="font-family:Verdana;">on I-V and P-V curves by considering the values of </span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">below </span><i><span style="font-family:Verdana;">n</span><sub><span style="font-family:Verdana;">o</span></sub></i><span style="font-family:Verdana;">. We have evaluated different iterative procedures of determining </span><i><span style="font-family:Verdana;">R<sub>sh</sub> </span></i><span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">R<sub>s</sub> </span></i><span style="font-family:Verdana;">at open-circuit, short-circuit point and the maximum-power points. These procedures have been classified into four approaches that guarantees positive shunt and series resistance for </span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">≤</span><i><span style="font-family:Verdana;"> n<sub>o</sub></span></i><span style="font-family:Verdana;">. These approaches have been categorized by deriving the saturation current as a dependent variable at each cardinal point with or without </span><i><span style="font-family:Verdana;">R<sub>s</sub> </span></i><span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">R<sub>sh</sub> </span></i><span style="font-family:Verdana;">pair. The values obtained for the five parameters have been used to simulate the photovoltaic solar module characteristic curves with great precision at different air temperatures and irradiances, considering the effect of Nominal Operating Cell Temperature (NOCT).展开更多
The multi-branched Husimi recursive lattice is extended to a virtual structure with fractional numbers of branches joined on one site. Although the lattice is undrawable in real space, the concept is consistent with r...The multi-branched Husimi recursive lattice is extended to a virtual structure with fractional numbers of branches joined on one site. Although the lattice is undrawable in real space, the concept is consistent with regular Husimi lattice. The Ising spins of antiferromagnetic interaction on such a set of lattices are calculated to check the critical temperatures(Tc) and ideal glass transition temperatures(Tk) variation with fractional branch numbers. Besides the similar results of two solutions representing the stable state(crystal) and metastable state(supercooled liquid)and indicating the phase transition temperatures, the phase transitions show a well-defined shift with branch number variation. Therefore the fractional branch number as a parameter can be used as an adjusting tool in constructing a recursive lattice model to describe real systems.展开更多
An inhomogeneous 2-dimensional recursive lattice formed by planar elements has been designed to investigate the thermodynamics of Ising spin system on the surface/thin film. The lattice is constructed as a hybrid of p...An inhomogeneous 2-dimensional recursive lattice formed by planar elements has been designed to investigate the thermodynamics of Ising spin system on the surface/thin film. The lattice is constructed as a hybrid of partial Husimi square lattice representing the bulk and 1D single bonds representing the surface. Exact calculations can be achieved with the recursive property of the lattice. The model has an anti-ferromagnetic interaction to give rise to an ordered phase identified as crystal, and a solution with higher energy to represent the amorphous/metastable phase.Free energy and entropy of the ideal crystal and supercooled liquid state of the model on the surface are calculated by the partial partition function. By analyzing the free energies and entropies of the crystal and supercooled liquid state,we are able to identify the melting and ideal glass transition on the surface. The results show that due to the variation of coordination number, the transition temperatures on the surface decrease significantly compared to the bulk system.Our calculation qualitatively agrees with both experimental and simulation works on the thermodynamics of surfaces and thin films conducted by others. Interactions between particles farther than the nearest neighbor distance are taken into consideration, and their effects are investigated.展开更多
Ground gravity survey was recently carried out in the Lolabe-Campo area, which constitutes the southern onshore portion of the Kribi-Campo sub-basin in South Cameroon. The obtained gravity data were processed and inte...Ground gravity survey was recently carried out in the Lolabe-Campo area, which constitutes the southern onshore portion of the Kribi-Campo sub-basin in South Cameroon. The obtained gravity data were processed and interpreted in order to elucidate the subsurface geology of the area in which preliminary studies highlighted the presence of an intrusive igneous body. In order to determine the nature and the characteristics of this body, spectral analysis, ideal body solution and 2.5D modelling methods were applied to the gravity data. The results suggest that the emplacement, breaking up and separation of the intrusive igneous body were the outcome of two tectonic events corresponding to an upward vertical translational tectonic movement followed by an anticlockwise rotational faulting tectonic movement. From a density contrast of 0.13 g·cmDž, the two isolated bodies have an estimated density of 2.80 g·cmDž which is comparatively higher than the average density of 2.67 g·cmDž of the autochthonous rocks. These two blocks are completely surrounded by both sedimentary and metamorphic formations and are confined between the depths of 0.6 km and 3.5 km. The highly dense nature of the rocks and their location around the Atlantic Ocean led to the conclusion that the two intrusive bodies are composed principally of gabbro. The disposition and shape of the open zone resulting from the separation of the blocks are suggestive of a trap for the accumulation of hydrocarbons and mineral resources.展开更多
The quest for an internal state variable constitutive model describing metal deformation is reviewed. First, analogy is drawn between a deformation model and the Ideal Gas Law. The use of strain as a variable in defor...The quest for an internal state variable constitutive model describing metal deformation is reviewed. First, analogy is drawn between a deformation model and the Ideal Gas Law. The use of strain as a variable in deformation models is discussed, and whether strain serves as an internal state variable is considered. A simple experiment that demonstrated path dependence in copper is described. The importance of defining appropriate internal state variables for a constitutive law relates to the ability to accurately model temperature and strain-rate dependencies in deformation simulations.展开更多
基金supported by the National Natural Science Foundation of China (Grant nos. 11033009, 11125315 and 11103086)
文摘From Kaula's Earth gravitational potential written in classical orbital elements, the unified ideal model of mean motion resonance of artificial satellites due to geopotential perturbations is developed in this paper first, through a suitable sequence of canonical transformations constructed by implicit functions. This unified ideal orbital resonance model is valid for all the commensurabilities between the rotational angular velocity of the Earth and the angular velocities of mean orbital motion of artificial satellites with arbitrary inclination and small eccentricity, and can be also transformed into Garfinkel's general expression of ideal resonance problem. Then 1/1 resonance of the 24-hour satellite with arbitrary inclination and small eccentricity is analyzed under the effect of harmonics of J2 and J 22 of the geopotential, based on the unified ideal model of mean motion resonance. The analytical expressions of the libration period and libration half width of the 1/1 resonance of the 24-hour satellite with arbitrary inclination and small eccentricity are presented.
文摘If there is no imagination, there is no music appreciation. It should create imaginary world for students in the music classroom teaching practice, and it should foster the students＇ musical imagination. Thus, colleagues can make discussion about strategies proposed including pilot background, context led, screen hygiene conditions and others. We use Cognitive Linguistic Theories to introduce idealized cognitive model and its theoretical basis and the intensified impact on student musical imagination.
文摘In the article a molecular model of oil with nanoparticles on the basis of the model of ideal fluid is considered. It is assumed that the molecular model of the oil can be represented as a homogenous distribution of identical molecules in space. It is assumed that the central interaction between the oil molecules and nanoparticles, results in a change of the model parameters. It is shown that for an ideal fluid the effect of nanoparticles is reduced to a change of the coefficient at the pressure.
基金Industrial Research of National Wool and Csahmere Industry Technology System,China(No.CARS-40-20)
文摘By comparing China's import of major imported agriculture textile material( cotton and wool),the characteristics of import are concluded. On this basis,a restricted version of source differentiated almost ideal demand system( RSDAIDS) is used to estimate the income and price elasticity of major imported agriculture textile material from the major sources based on the data from 1992 to 2015. The results are shown as follows.( 1) Although the dependency on imported cotton is lower than wool, the fluctuation of cotton import is much more drastic; China's demand for cotton is relatively price elastic with higher expenditure elasticity compared with wool; besides,the existence of complementarity is proved between imported cotton and wool.( 2) According to the import elasticity of cotton,demand for cotton imported from India shows priority over cotton from other sources; demand for cotton imported from America is the most price-sensitive one; substitution among cotton from different sources is weak.( 3) According to the import elasticity of wool,wool imported from Uruguay has bright market prospects. In addition,wool imported from Australia has irreplaceable advantage than that from New Zealand.
文摘Knowledge about the amino acid requirements and the response of pigs to the amino acid supply is essential in feed formulation. A deficient AA supply results in a reduction in performance while an oversupply is costly and leads to excessive nitrogen excretion with a potentially negative environmental impact. Amino acid requirements are determined to a large extent by the protein deposition in the body and, for lactating sows, by the protein exported in the milk. The concept of ideal protein was developed more than 50 years ago and refers to a protein with an amino acid profile that exactly meets the animal＇s requirement so that all amino acids are equally limiting for performance. Because Lys typically is the first-limiting amino acid, the ideal amino acid profile is often expressed relative to Lys. Although the ideal protein profile is often assumed to be constant for a given production stage, （small） changes in the ideal protein profile can occur within a production stage. This can be caused by changes in the relative contribution of the different components of amino acid requirements during the productive life on the animal （e.g. changes in the relative contribution of growth and maintenance）. Amino acids requirements can be determined experimentally using dose-response studies. The design of the study, the chosen response criterion, and the statistical model affect the requirement estimate. Although considerable experimental work has been carried out to determine the requirements for Lys, Met, Thr, and Trp in growing pigs （and to a lesser extent in sows）, little is known about the requirements for the other essential amino acids. Experimental dose-response studies generally focus on the requirement and less on the overall response （i.e. what are the consequences of an amino acid deficiency？）. This latter aspect is, to some extent, accounted for in modelling approaches that quantify the response of the animal to the amino acid supply in a dynamic way. The paper describes the origin of ideal protein and illustrates how fundamental concepts of amino acid nutrition have been integrated in practical modeling approaches for the nutrition of growing pigs and sows.
基金The study was supported by ＂Cities Farming for the Future, RUAF-CFF＂, funded by DGIS of the Netherlands and IDRC of Canada and the National Natural Science Foundation of China （70503007）+1 种基金 the Graduate＇s Scientific Research Foundation of Hunan Province and the Graduate＇s Scientific Research Foundation of Central South University of Forestry and Technology （2006bx03）
文摘This paper described the main four basic models of ideal landscape in the Mount Lushan National Park as Kunlunshan model, Xumishan model, Peach flower land model, Christian model. Five typical places in Mount Lushan with the ideal landscape characteristics like the East Grove Temple, White Deer Cave Academy, Simplicity and Tranquility Monastery, Lushan Valley, and Villa-cluster of the East Valley were analyzed, and the integration of the basic models for each place was discussed to make the realistic landscape conform to the ideal needs. Moreover, the discussions also involved the characteristics of ideal landscape that are featured in resource, culture, structure, function, process, scale and region. In conclusion, ideal landscape in the Mount Lushan National Park was the product of the interaction between human and nature. Mount Lushan inherits the essence of Chinese traditional culture with a history of more than 1000 years; and it also absorbs the manna of the Western culture as well as the exchanges between nature and humanities together with the conflict and adaptation among different cultures. The natural landscape could be satisfied with the survival demand and cultural taste of mankind by the way of ecological planning.
文摘In this paper hybrid converters with double inputs are investigated. Mainly any possible topologies are constructed and only one of them is chosen and modeled in none ideal format, by state space averaging method. After that small signal model and equilibrium point of that model is calculated. Finally with power sharing analysis the best point in efficiency was calculated.
基金supported by the State Key Program of National Natural Science Foundation of China(Grants No.11731008)the National Natural Science Foundation of China(Grants No.10771087)。
文摘The ideal reaction chromatography model can be regarded as a semi-coupled system of two hyperbolic partial differential equations,in which,one is a self-closed nonlinear equation for the reactant concentration and another is a linear equation coupling the reactant concentration for the resultant concentration.This paper is concerned with the initial-boundary value problem for the above model.By the characteristic method and the truncation method,we construct the global weak entropy solution of this initial initial-boundary value problem for Riemann type of initial-boundary data.Moreover,as examples,we apply the obtained results to the cases of head-on and wide pulse injections and give the expression of the global weak entropy solution.
文摘From the analysis of helical characteristics, ideal geometric models of cutting edge and helical groove of nose burr are developed to realize the ideal geometric model of helical groove of nose burr, in terms of not only the shape of cutting edge being accurately machined but also rake angle and depth of groove in fall compliance with design requirements. The fundamental relationship of too-groove engagment for groove shaping and the complex formulas related are verified by the example of machining and its computer simulation.
基金Part of the present work is supported by the Grant-in-Aid for Scientific Research(KAKENHI)of the Japan Society for the Promotion of Science(Nos.18H01584,JP20J20811)This support is greatly appreciated.
文摘A new method of robust damper design is presented for elastic-plastic multi-degree-of-freedom(MDOF)building structures under multi-level ground motions(GMs).This method realizes a design that is effective for various levels of GMs.The robustness of a design is measured by an incremental dynamic analysis(IDA)curve and an ideal drift response curve(IDRC).The IDRC is a plot of the optimized maximum deformation under a constraint on the total damper quantity vs.the design level of the GMs.The total damper quantity corresponds to the total cost of the added dampers.First,a problem of generation of IDRCs is stated.Then,its solution algorithm,which consists of the sensitivity-based algorithm(SBA)and a local search method,is proposed.In the application of the SBA,the passive added dampers are removed sequentially under the specified-level GMs.On the other hand,the proposed local search method can search the optimal solutions for a constant total damper quantity under GMs’increased levels.In this way,combining these two algorithms enables the comprehensive search of the optimal solutions for various conditions of the status of the GMs and the total damper quantity.The influence of selecting the type of added dampers(oil,hysteretic,and so on)and the selection of the input GMs on the IDRCs are investigated.Finally,a robust optimal design problem is formulated,and a simple local search-based algorithm is proposed.A simple index using the IDRC and the IDA curve of the model is used as the objective function.It is demonstrated that the proposed algorithm works well in spite of its simplicity.
文摘A single diode model for a photovoltaic solar module is the most ideal and quick way of analyzing the module characteristics before implementing them in a solar plant. Solar modules manufacturers provide information for three critical points that are essential in I-V, P-V or P-I curves. In this study, we propose four separate simulation procedures to estimate the five-model parameters of an analogous single diode equivalent circuit by utilizing three cardinal points of the photovoltaic module I-V curve, described from experimental data using a solar simulator and manufacturer’s datasheet. The main objective is to extract and use the five unknown parameters of a single diode model to describe the photovoltaic system using I-V ad P-V plots under different environmental conditions. The most influential parameters that greatly alter the cardinal points defined at short circuit point (SCP), the maximum power point (MPP) and the open circuit point(OCP) are the ideality factor (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;">) and the diode saturation current (</span><i><span style="font-family:Verdana;">I<sub>o</sub></span></i><span style="font-family:Verdana;">). For a quick and fast convergence, we have determined the optimal ideality factor (</span><i><span style="font-family:Verdana;">n<sub>o</sub></span></i><span style="font-family:Verdana;">) and optimal saturation current (</span><i><span style="font-family:Verdana;">I<sub>oopt</sub></span></i><span style="font-family:Verdana;">) as the primary parameters by first assuming the optimal values of </span><i><span style="font-family:Verdana;">R<sub>sh</sub></span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">R<sub>s</sub> </span></i><span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">I<sub>ph</sub> </span></i><span style="font-family:Verdana;">at standard test conditions (STC). Further, we evaluated the effects of </span><i><span style="font-family:Verdana;">I<sub>ph</sub></span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">R<sub>s</sub> </span></i><span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">R<sub>sh</sub> </span></i><span style="font-family:Verdana;">on I-V and P-V curves by considering the values of </span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">below </span><i><span style="font-family:Verdana;">n</span><sub><span style="font-family:Verdana;">o</span></sub></i><span style="font-family:Verdana;">. We have evaluated different iterative procedures of determining </span><i><span style="font-family:Verdana;">R<sub>sh</sub> </span></i><span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">R<sub>s</sub> </span></i><span style="font-family:Verdana;">at open-circuit, short-circuit point and the maximum-power points. These procedures have been classified into four approaches that guarantees positive shunt and series resistance for </span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">≤</span><i><span style="font-family:Verdana;"> n<sub>o</sub></span></i><span style="font-family:Verdana;">. These approaches have been categorized by deriving the saturation current as a dependent variable at each cardinal point with or without </span><i><span style="font-family:Verdana;">R<sub>s</sub> </span></i><span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">R<sub>sh</sub> </span></i><span style="font-family:Verdana;">pair. The values obtained for the five parameters have been used to simulate the photovoltaic solar module characteristic curves with great precision at different air temperatures and irradiances, considering the effect of Nominal Operating Cell Temperature (NOCT).
文摘The multi-branched Husimi recursive lattice is extended to a virtual structure with fractional numbers of branches joined on one site. Although the lattice is undrawable in real space, the concept is consistent with regular Husimi lattice. The Ising spins of antiferromagnetic interaction on such a set of lattices are calculated to check the critical temperatures(Tc) and ideal glass transition temperatures(Tk) variation with fractional branch numbers. Besides the similar results of two solutions representing the stable state(crystal) and metastable state(supercooled liquid)and indicating the phase transition temperatures, the phase transitions show a well-defined shift with branch number variation. Therefore the fractional branch number as a parameter can be used as an adjusting tool in constructing a recursive lattice model to describe real systems.
基金Supported by the National Natural Science Foundation of China under Grant No.11505110Shanghai Pujiang Talent Program under Grant No.16PJ1431900the China Postdoctoral Science Foundation under Grant No.2016M591666
文摘An inhomogeneous 2-dimensional recursive lattice formed by planar elements has been designed to investigate the thermodynamics of Ising spin system on the surface/thin film. The lattice is constructed as a hybrid of partial Husimi square lattice representing the bulk and 1D single bonds representing the surface. Exact calculations can be achieved with the recursive property of the lattice. The model has an anti-ferromagnetic interaction to give rise to an ordered phase identified as crystal, and a solution with higher energy to represent the amorphous/metastable phase.Free energy and entropy of the ideal crystal and supercooled liquid state of the model on the surface are calculated by the partial partition function. By analyzing the free energies and entropies of the crystal and supercooled liquid state,we are able to identify the melting and ideal glass transition on the surface. The results show that due to the variation of coordination number, the transition temperatures on the surface decrease significantly compared to the bulk system.Our calculation qualitatively agrees with both experimental and simulation works on the thermodynamics of surfaces and thin films conducted by others. Interactions between particles farther than the nearest neighbor distance are taken into consideration, and their effects are investigated.
文摘Ground gravity survey was recently carried out in the Lolabe-Campo area, which constitutes the southern onshore portion of the Kribi-Campo sub-basin in South Cameroon. The obtained gravity data were processed and interpreted in order to elucidate the subsurface geology of the area in which preliminary studies highlighted the presence of an intrusive igneous body. In order to determine the nature and the characteristics of this body, spectral analysis, ideal body solution and 2.5D modelling methods were applied to the gravity data. The results suggest that the emplacement, breaking up and separation of the intrusive igneous body were the outcome of two tectonic events corresponding to an upward vertical translational tectonic movement followed by an anticlockwise rotational faulting tectonic movement. From a density contrast of 0.13 g·cmDž, the two isolated bodies have an estimated density of 2.80 g·cmDž which is comparatively higher than the average density of 2.67 g·cmDž of the autochthonous rocks. These two blocks are completely surrounded by both sedimentary and metamorphic formations and are confined between the depths of 0.6 km and 3.5 km. The highly dense nature of the rocks and their location around the Atlantic Ocean led to the conclusion that the two intrusive bodies are composed principally of gabbro. The disposition and shape of the open zone resulting from the separation of the blocks are suggestive of a trap for the accumulation of hydrocarbons and mineral resources.
文摘The quest for an internal state variable constitutive model describing metal deformation is reviewed. First, analogy is drawn between a deformation model and the Ideal Gas Law. The use of strain as a variable in deformation models is discussed, and whether strain serves as an internal state variable is considered. A simple experiment that demonstrated path dependence in copper is described. The importance of defining appropriate internal state variables for a constitutive law relates to the ability to accurately model temperature and strain-rate dependencies in deformation simulations.
