Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analys...Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analysis and exergy cost optimization in petrochemical industry is of great economic and environmental significance. Based on the main fractionator in Jiujiang Petrochemical Complex No. 2 FCCU, an enhanced exergy cost optimization under different operating conditions by adjusting set points of temperature and valves opening degree for flow control is studied in this paper in order to reduce exergy cost and improve the quality of energy. A steadystate optimization algorithm to enhance exergy availability and an objective function comprehensively considering exergy loss are proposed. On the basis of ensuring the quality of petroleum products, the economic benefits can be improved by optimizing the controllable variables due to the fact that exergy cost is decreased.展开更多
This article presents a new method to calculate the composition differences (e) for tar g.etin.g the minimum total annualized cost (TAC) of a mass exchange network (MEN),which is based on the combination of comp...This article presents a new method to calculate the composition differences (e) for tar g.etin.g the minimum total annualized cost (TAC) of a mass exchange network (MEN),which is based on the combination of composition interval diagram (CID) with mathematical programming.The total cost target consists of the capital cost of the process units and the operating cost for mass separating agents (MS.As). The value of total cost varies considerablv with the composition differences, so the values of e should be optimized in order to obtain minimum TAC of a MEN. This articleconsiders ε as a set of unequal variables for each equilibrium equation of a rich-lean stream pair, employing them to build the CID and mathematical model, which optimizes the structure and composition differences simultaneously. Two examples are applied to illustrate the proposed method and the results demonstrate that the approach introduced by this article is simpler and more convenient than the methods in previous literatures.展开更多
In today's knowledge-based economy, the role played by human capital in the determination of the market value of a firm is recognized. To be able to persist in the open competition, entities are forced to invest incr...In today's knowledge-based economy, the role played by human capital in the determination of the market value of a firm is recognized. To be able to persist in the open competition, entities are forced to invest increasingly in the professional training of their employees. Inconsistent with this rising importance is the prohibition to capitalize professional training cost according to international accounting standards (IAS) 38.69 (b). Highly qualified employees ensure competitive advantages and thus lead to an increase in shareholder value. Regarding the financial statement as a primary source of information, it does not seem reasonable to leave such a valuable resource completely unnoticed in the balance sheet. Consequently, a truthful representation of a firm's asset should take training costs into account. This article pleads for a limitation of this general legal prohibition and analyzes under which premises those expenditures for training can comply with the common criteria of capitalization according to IAS 38.展开更多
AIM To evaluate the pathogenic role of toll-like receptor(TLR) gene polymorphisms in patients with nonalcoholic fatty liver disease(NAFLD).METHODS Two hundred and fifty subjects(NAFLD = 200, healthy volunteers = 50) u...AIM To evaluate the pathogenic role of toll-like receptor(TLR) gene polymorphisms in patients with nonalcoholic fatty liver disease(NAFLD).METHODS Two hundred and fifty subjects(NAFLD = 200, healthy volunteers = 50) underwent polymerase chain reaction and restriction fragment length polymorphism to assess one polymorphism in the toll-like receptor 2(TLR2) gene(A753G), two polymorphisms in the TLR4 gene(TLR4 Asp299 Gly and Thr399 Ile allele), and two polymorphisms in the cluster of differentiation 14(CD14)(C-159 T and C-550T) gene, a co-receptor of TLR4. Association of TLR gene polymorphisms with NAFLD and its severity was evaluated by genetic models of association.RESULTS On both multiplicative and recessive models of gene polymorphism association, there was significant association of CD14 C(-159) T polymorphism with NAFLD; patients with TT genotype had a 2.6 fold increased risk of developing NAFLD in comparison to CC genotype. There was no association of TLR2 Arg753 Gln, TLR4 Asp299 Gly, Thr399 Ile, and CD14 C(-550) T polymorphisms with NAFLD. None of the TLR gene polymorphisms had an association with histological severity of NAFLD.CONCLUSION Patients with CD14 C(-159) T gene polymorphism, a co-receptor of TLR4, have an increased risk of NAFLD development.展开更多
This paper presents a generalized model for determining minimum cost preventive maintenance schedules for a maintained reliability system. Through balancing the cost of system failure during operation against the cos...This paper presents a generalized model for determining minimum cost preventive maintenance schedules for a maintained reliability system. Through balancing the cost of system failure during operation against the cost of planned maintenance, an optimal policy is established which minimizes the expected cost rate. A simple equation to determine the optimal period between maintenances for a system with the known failure distribution is acquired, and the calculation for the system with Gamma failure distribution is given.展开更多
The bottleneck analysis of the minimum cost problem for the generalized network (MCPGN) is discussed. The analysis is based on the network simplex algorithm, which gains negative cost graphs by constructing augmented ...The bottleneck analysis of the minimum cost problem for the generalized network (MCPGN) is discussed. The analysis is based on the network simplex algorithm, which gains negative cost graphs by constructing augmented forest structure, then augments flows on the negative cost graphs until the optimal revolution is gained. Bottleneck structure is presented after analyzing the augmented forest structure. The negative cost augmented graphs are constructed with the bottleneck structure. The arcs that block the negative cost augmented graph are the elements of the bottleneck. The bottleneck analysis for the generalized circulation problem, the minimum circulation problem and the circulation problem are discussed respectively as the basal problems, then that for MCPGN is achieved. An example is presented at the end.展开更多
We analyze an infinite horizon difference game between four aggregated industries-production of producer goods, production of consumption goods, federation of labor unions, and commercial banking sector. Consumers do ...We analyze an infinite horizon difference game between four aggregated industries-production of producer goods, production of consumption goods, federation of labor unions, and commercial banking sector. Consumers do not behave strategically. They make their decisions on the basis of maximization of average discounted utility. Therefore, we do not include them in the set of players in the game. The payoffof each production industry and the commercial banking sector is equal to the average discounted sum of real dividends of its owners. The payoff of the federation of labor unions is equal to the average discounted sum of real wages and real unemployment benefits. A strict strong perfect general equilibrium is the applied solution concept for the game. It requires that there does not exist a coalition of players that can weakly Pareto improve the vector of continuation payoffs of its members in some subgame by a coordinated deviation. It is a refinement of Rubinstein's concept of a strong perfect equilibrium. We formulate and prove the sufficient condition for its existence. It is based on the assumption that no one of the aggregated industries can have a positive output without using some minimal amount of output of each other aggregated industry as an input. By definition, in each subgame, the equilibrium payoff vector in a strict strong perfect general equilibrium is strictly Pareto efficient. Thus, if each consumer either has only income from wage and unemployment benefit or receives dividend from only one aggregated industry, and his nominal income in each period along the equilibrium path exceeds social minimum, it is not possible to weakly Pareto improve the vector of consumers' average discounted real incomes. This holds not only for the whole game but also for each subgame starting in the first phase of some period.展开更多
By means of critical behaviors of the dynamical fermion mass in four-fermion interaction models, we show by explicit calculations that when T = 0 the particle density will have a discontinuous jumping across the criti...By means of critical behaviors of the dynamical fermion mass in four-fermion interaction models, we show by explicit calculations that when T = 0 the particle density will have a discontinuous jumping across the critical chemical potential μ<SUB>c</SUB> in 2D and 3D Gross-Neveu (GN) model and these physically explain the first-order feature of the corresponding symmetry restoring phase transitions. For the second-order phase transitions in the 3D GN model when T → 0 and in 4D Nambu–Jona–Lasinio (NJL) model when T = 0, it is proven that the particle density itself will be continuous across μ<SUB>c</SUB> but its derivative over the chemical potential μ will have a discontinuous jumping. The results give a physical explanation of implications of the tricritical point in the 3D GN model. The discussions also show effectiveness of the critical analysis approach of phase transitions.展开更多
Under the smart grid paradigm, in the near future all consumers will be exposed to variable pricing schemes introduced by utilities. Hence, there is a need to develop algorithms which could be used by the consumers to...Under the smart grid paradigm, in the near future all consumers will be exposed to variable pricing schemes introduced by utilities. Hence, there is a need to develop algorithms which could be used by the consumers to schedule their loads. In this paper, load scheduling problem is formulated as a LCP (load commitment problem). The load model is general and can model atomic and non-atomic loads. Furthermore, it can also take into consideration the relative discomfort caused by delay in scheduling any load. For this purpose, a single parameter "uric" is introduced in the load model which captures the relative discomfort caused by delay in scheduling a particular load. Guidelines for choosing this parameter are given. All the other parameters of the proposed load model can be easily specified by the consumer. The paper shows that the general LCP can be viewed as multi-stage decision making problem or a MDP (Markov decision problem). RL (reinforcement learning) based algorithm is developed to solve this problem. The efficacy of the algorithm is investigated when the price of electricity is available in advance as well as for the case when it is random. The scalability of the approach is also investigated.展开更多
High density of buildings and population in urban areas increases urban temperature, generally known as the urban heat island. Raised temperature, especially in SUlIuner, alms city centers into unwelcome hot areas, wi...High density of buildings and population in urban areas increases urban temperature, generally known as the urban heat island. Raised temperature, especially in SUlIuner, alms city centers into unwelcome hot areas, with direct effects on electricity demand and energy consttrnption for cooling buildings and increases the production of carbon dioxide and other pollutants. Therefore, by considering that the energy consumption in the world has been faced with intense crisis, it becomes increasingly important to study the effects of urban heat island on energy constunption in order to improve people's environment and decrease energy use in cities. This paper, therefore, is focused on urbanization and population size factors to understand tile influence way of these factors on formation of UHI and energy consumption balance. To achieve this aim, this paper explores literally the conceptual framework of confliction between population and urban structure, which produce UHI intensity and affected energy consumption balance. It is then discussed how these two factors can be affected and give implication to the city, and then, focuses on whether actions should be taken for balancing adaptation and mitigation UHI effects. It will be concluded by making the recommendations for preventive action and provide quality of life.展开更多
An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation withou...An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation without any photocatalyst at room temperature in good chemical yields.展开更多
Ion exchange membranes(IEMs) play a significant role in fields of energy and environment, for instance fuel cells, diffusion dialysis, electrodialysis, etc. The limited choice of commercially available IEMs has produc...Ion exchange membranes(IEMs) play a significant role in fields of energy and environment, for instance fuel cells, diffusion dialysis, electrodialysis, etc. The limited choice of commercially available IEMs has produced a strong demand of fabricating IEMs with improved properties via facile synthetic strategies over the past two decades. Poly(phenylene oxide)(PPO) is considered as a promising polymeric material for constructing practical IEMs, due to its advantages of good physicochemical properties, low manufacturing cost and easy post functionalization. In this review, we present the accumulated efforts in synthetic strategies towards diverse types of PPO-based IEMs. Relation between polymer structures and the resulted features is discussed in detail. Besides, applying IEMs from PPO and its derivatives in fuel cell, diffusion dialysis and electrodialysis is summarized and commented.展开更多
China is facing challenges of the increasing incidence of some chronic diseases. However, the share of government spending on health in total kept fairing during the economic transition and the cost of health care has...China is facing challenges of the increasing incidence of some chronic diseases. However, the share of government spending on health in total kept fairing during the economic transition and the cost of health care has been rising dramatically. Using the data at the provincial level, I find that income and population aging are significant determinants of increasing health expenditure. Time dummies contribute more than 40% in the growth of health expenditure and nearly one-third in the growth rate of health expenditure, which implies that technological and institutional changes are also very important drivers in China. In the future, the rising of health expenditure is a necessary response to income growth and population aging; but there is still plenty of room to cut the cost through reforming the health care sector.展开更多
At present, most airlines adopted generally the same amount of compensa- tion strategy when needing to provide financial compensation to all flight delay passengers. However, due to the existence of differences in tra...At present, most airlines adopted generally the same amount of compensa- tion strategy when needing to provide financial compensation to all flight delay passengers. However, due to the existence of differences in travel time value, ticket fare, as well as the expectation of compensation for flight delays, the gap between the effect of same amount of compensation and many passengers' (especially the high-value ones) expectations is large, it results in that airlines need to pay higher cost of compensation, but the total effect of compensation for passengers are not better. This paper advanced four financial com- pensation strategies for flight delays, summarized their own characteristics, and took into account the interests of both airlines and passengers, built the optimization models of the four financial compensation strategies under the restriction of the airline's compensation cost and on the goal of the maximum total effectiveness of the financial compensation to all passengers. Finally, based on the specific circumstances of the flight delays, the paper discussed the method for airline to choose the optimal financial compensation strategy through solving four models and comparing the compensation effectiveness.展开更多
基金Supported by the National Natural Science Foundation of China(61590924,61673273,61521063)
文摘Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analysis and exergy cost optimization in petrochemical industry is of great economic and environmental significance. Based on the main fractionator in Jiujiang Petrochemical Complex No. 2 FCCU, an enhanced exergy cost optimization under different operating conditions by adjusting set points of temperature and valves opening degree for flow control is studied in this paper in order to reduce exergy cost and improve the quality of energy. A steadystate optimization algorithm to enhance exergy availability and an objective function comprehensively considering exergy loss are proposed. On the basis of ensuring the quality of petroleum products, the economic benefits can be improved by optimizing the controllable variables due to the fact that exergy cost is decreased.
文摘This article presents a new method to calculate the composition differences (e) for tar g.etin.g the minimum total annualized cost (TAC) of a mass exchange network (MEN),which is based on the combination of composition interval diagram (CID) with mathematical programming.The total cost target consists of the capital cost of the process units and the operating cost for mass separating agents (MS.As). The value of total cost varies considerablv with the composition differences, so the values of e should be optimized in order to obtain minimum TAC of a MEN. This articleconsiders ε as a set of unequal variables for each equilibrium equation of a rich-lean stream pair, employing them to build the CID and mathematical model, which optimizes the structure and composition differences simultaneously. Two examples are applied to illustrate the proposed method and the results demonstrate that the approach introduced by this article is simpler and more convenient than the methods in previous literatures.
文摘In today's knowledge-based economy, the role played by human capital in the determination of the market value of a firm is recognized. To be able to persist in the open competition, entities are forced to invest increasingly in the professional training of their employees. Inconsistent with this rising importance is the prohibition to capitalize professional training cost according to international accounting standards (IAS) 38.69 (b). Highly qualified employees ensure competitive advantages and thus lead to an increase in shareholder value. Regarding the financial statement as a primary source of information, it does not seem reasonable to leave such a valuable resource completely unnoticed in the balance sheet. Consequently, a truthful representation of a firm's asset should take training costs into account. This article pleads for a limitation of this general legal prohibition and analyzes under which premises those expenditures for training can comply with the common criteria of capitalization according to IAS 38.
基金Supported by Indian Council of Medical Research(ICMR),New Delhi,No.5/4/3-7/2009-NCD-II
文摘AIM To evaluate the pathogenic role of toll-like receptor(TLR) gene polymorphisms in patients with nonalcoholic fatty liver disease(NAFLD).METHODS Two hundred and fifty subjects(NAFLD = 200, healthy volunteers = 50) underwent polymerase chain reaction and restriction fragment length polymorphism to assess one polymorphism in the toll-like receptor 2(TLR2) gene(A753G), two polymorphisms in the TLR4 gene(TLR4 Asp299 Gly and Thr399 Ile allele), and two polymorphisms in the cluster of differentiation 14(CD14)(C-159 T and C-550T) gene, a co-receptor of TLR4. Association of TLR gene polymorphisms with NAFLD and its severity was evaluated by genetic models of association.RESULTS On both multiplicative and recessive models of gene polymorphism association, there was significant association of CD14 C(-159) T polymorphism with NAFLD; patients with TT genotype had a 2.6 fold increased risk of developing NAFLD in comparison to CC genotype. There was no association of TLR2 Arg753 Gln, TLR4 Asp299 Gly, Thr399 Ile, and CD14 C(-550) T polymorphisms with NAFLD. None of the TLR gene polymorphisms had an association with histological severity of NAFLD.CONCLUSION Patients with CD14 C(-159) T gene polymorphism, a co-receptor of TLR4, have an increased risk of NAFLD development.
文摘This paper presents a generalized model for determining minimum cost preventive maintenance schedules for a maintained reliability system. Through balancing the cost of system failure during operation against the cost of planned maintenance, an optimal policy is established which minimizes the expected cost rate. A simple equation to determine the optimal period between maintenances for a system with the known failure distribution is acquired, and the calculation for the system with Gamma failure distribution is given.
基金Supported by the National Natural Science Foundation of China (No. 60174046).
文摘The bottleneck analysis of the minimum cost problem for the generalized network (MCPGN) is discussed. The analysis is based on the network simplex algorithm, which gains negative cost graphs by constructing augmented forest structure, then augments flows on the negative cost graphs until the optimal revolution is gained. Bottleneck structure is presented after analyzing the augmented forest structure. The negative cost augmented graphs are constructed with the bottleneck structure. The arcs that block the negative cost augmented graph are the elements of the bottleneck. The bottleneck analysis for the generalized circulation problem, the minimum circulation problem and the circulation problem are discussed respectively as the basal problems, then that for MCPGN is achieved. An example is presented at the end.
文摘We analyze an infinite horizon difference game between four aggregated industries-production of producer goods, production of consumption goods, federation of labor unions, and commercial banking sector. Consumers do not behave strategically. They make their decisions on the basis of maximization of average discounted utility. Therefore, we do not include them in the set of players in the game. The payoffof each production industry and the commercial banking sector is equal to the average discounted sum of real dividends of its owners. The payoff of the federation of labor unions is equal to the average discounted sum of real wages and real unemployment benefits. A strict strong perfect general equilibrium is the applied solution concept for the game. It requires that there does not exist a coalition of players that can weakly Pareto improve the vector of continuation payoffs of its members in some subgame by a coordinated deviation. It is a refinement of Rubinstein's concept of a strong perfect equilibrium. We formulate and prove the sufficient condition for its existence. It is based on the assumption that no one of the aggregated industries can have a positive output without using some minimal amount of output of each other aggregated industry as an input. By definition, in each subgame, the equilibrium payoff vector in a strict strong perfect general equilibrium is strictly Pareto efficient. Thus, if each consumer either has only income from wage and unemployment benefit or receives dividend from only one aggregated industry, and his nominal income in each period along the equilibrium path exceeds social minimum, it is not possible to weakly Pareto improve the vector of consumers' average discounted real incomes. This holds not only for the whole game but also for each subgame starting in the first phase of some period.
基金The project supported by National Natural Science Foundation ot China
文摘By means of critical behaviors of the dynamical fermion mass in four-fermion interaction models, we show by explicit calculations that when T = 0 the particle density will have a discontinuous jumping across the critical chemical potential μ<SUB>c</SUB> in 2D and 3D Gross-Neveu (GN) model and these physically explain the first-order feature of the corresponding symmetry restoring phase transitions. For the second-order phase transitions in the 3D GN model when T → 0 and in 4D Nambu–Jona–Lasinio (NJL) model when T = 0, it is proven that the particle density itself will be continuous across μ<SUB>c</SUB> but its derivative over the chemical potential μ will have a discontinuous jumping. The results give a physical explanation of implications of the tricritical point in the 3D GN model. The discussions also show effectiveness of the critical analysis approach of phase transitions.
文摘Under the smart grid paradigm, in the near future all consumers will be exposed to variable pricing schemes introduced by utilities. Hence, there is a need to develop algorithms which could be used by the consumers to schedule their loads. In this paper, load scheduling problem is formulated as a LCP (load commitment problem). The load model is general and can model atomic and non-atomic loads. Furthermore, it can also take into consideration the relative discomfort caused by delay in scheduling any load. For this purpose, a single parameter "uric" is introduced in the load model which captures the relative discomfort caused by delay in scheduling a particular load. Guidelines for choosing this parameter are given. All the other parameters of the proposed load model can be easily specified by the consumer. The paper shows that the general LCP can be viewed as multi-stage decision making problem or a MDP (Markov decision problem). RL (reinforcement learning) based algorithm is developed to solve this problem. The efficacy of the algorithm is investigated when the price of electricity is available in advance as well as for the case when it is random. The scalability of the approach is also investigated.
文摘High density of buildings and population in urban areas increases urban temperature, generally known as the urban heat island. Raised temperature, especially in SUlIuner, alms city centers into unwelcome hot areas, with direct effects on electricity demand and energy consttrnption for cooling buildings and increases the production of carbon dioxide and other pollutants. Therefore, by considering that the energy consumption in the world has been faced with intense crisis, it becomes increasingly important to study the effects of urban heat island on energy constunption in order to improve people's environment and decrease energy use in cities. This paper, therefore, is focused on urbanization and population size factors to understand tile influence way of these factors on formation of UHI and energy consumption balance. To achieve this aim, this paper explores literally the conceptual framework of confliction between population and urban structure, which produce UHI intensity and affected energy consumption balance. It is then discussed how these two factors can be affected and give implication to the city, and then, focuses on whether actions should be taken for balancing adaptation and mitigation UHI effects. It will be concluded by making the recommendations for preventive action and provide quality of life.
基金supported by the National Natural Science Foundation of China(2147208481421091)+2 种基金the Qing Lan Project of Jiangsu Province and State Key Laboratory of Bioorganic & Natural Products ChemistryShanghai Institute of Organic ChemistryChinese Academy of Sciences
文摘An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation without any photocatalyst at room temperature in good chemical yields.
基金supported by the National Natural Science Foundation of China (21506201, 21720102003, 91534203)the Key Technologies R&D Program of Anhui Province (17030901079)+1 种基金K. C. Wong Education Foundation (2016-11)International Partnership Program of Chinese Academy of Sciences (21134ky5b20170010)
文摘Ion exchange membranes(IEMs) play a significant role in fields of energy and environment, for instance fuel cells, diffusion dialysis, electrodialysis, etc. The limited choice of commercially available IEMs has produced a strong demand of fabricating IEMs with improved properties via facile synthetic strategies over the past two decades. Poly(phenylene oxide)(PPO) is considered as a promising polymeric material for constructing practical IEMs, due to its advantages of good physicochemical properties, low manufacturing cost and easy post functionalization. In this review, we present the accumulated efforts in synthetic strategies towards diverse types of PPO-based IEMs. Relation between polymer structures and the resulted features is discussed in detail. Besides, applying IEMs from PPO and its derivatives in fuel cell, diffusion dialysis and electrodialysis is summarized and commented.
基金The author is grateful for financial support from the National Science Foundation of China(70573024, 70973027 )
文摘China is facing challenges of the increasing incidence of some chronic diseases. However, the share of government spending on health in total kept fairing during the economic transition and the cost of health care has been rising dramatically. Using the data at the provincial level, I find that income and population aging are significant determinants of increasing health expenditure. Time dummies contribute more than 40% in the growth of health expenditure and nearly one-third in the growth rate of health expenditure, which implies that technological and institutional changes are also very important drivers in China. In the future, the rising of health expenditure is a necessary response to income growth and population aging; but there is still plenty of room to cut the cost through reforming the health care sector.
文摘At present, most airlines adopted generally the same amount of compensa- tion strategy when needing to provide financial compensation to all flight delay passengers. However, due to the existence of differences in travel time value, ticket fare, as well as the expectation of compensation for flight delays, the gap between the effect of same amount of compensation and many passengers' (especially the high-value ones) expectations is large, it results in that airlines need to pay higher cost of compensation, but the total effect of compensation for passengers are not better. This paper advanced four financial com- pensation strategies for flight delays, summarized their own characteristics, and took into account the interests of both airlines and passengers, built the optimization models of the four financial compensation strategies under the restriction of the airline's compensation cost and on the goal of the maximum total effectiveness of the financial compensation to all passengers. Finally, based on the specific circumstances of the flight delays, the paper discussed the method for airline to choose the optimal financial compensation strategy through solving four models and comparing the compensation effectiveness.