Based on the geographical circumstance, climate and the boundary layer meteorology features of the Pearl River Delta, a boundary layer concept model of the Pearl River Delta was built. The concept model consists of fo...Based on the geographical circumstance, climate and the boundary layer meteorology features of the Pearl River Delta, a boundary layer concept model of the Pearl River Delta was built. The concept model consists of four fundamental factors that affect the boundary layer meteorology of the Pearl River Delta and can convincingly explain the reason of the air quality change in the Pearl River Delta. The model can be used to the diffusion capability analysis, the air pollution potential forecasting or haze forecasting, etc.展开更多
Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issue...Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issues in hydrometallurgical cut-off grades determination. Slags are remarked as one of the main sources of copper. It is not only regarded as a waste but also identified as another resource extracting base metals. Slags are characterized by copper high grade. Thus, slag copper recovery can be led to different cut-off grades and net present value(NPV). The current research scrutinizes the effect of slag recovery by both flotation and hydrometallurgical methods on the hydrometallurgical cut-off grades. For this purpose, the optimum cut-off grade algorithms of hydrometallurgical methods are developed by considering associated environmental parameters, incomes and also the costs. Then, their optimum amounts are calculated with NPV maximization as an objective function. The results indicate that considering slag copper recovery in the hydrometallurgical cut-off grade algorithms reduces the environmental costs caused by slag dumping and leads to more NPV by 9%.展开更多
In order to solve the heat damages in deep mines, a cool-wall cooling technology and its working model are proposed based on the principles of heat absorption and insulation in this paper. During this process, the dif...In order to solve the heat damages in deep mines, a cool-wall cooling technology and its working model are proposed based on the principles of heat absorption and insulation in this paper. During this process, the differential equation of thermal equilibrium for roadway control unit is built, and the heat adsorption control equation of cool-wall cooling system is derived by an integral method, so as to obtain the quantitative relationship among the heat absorption capacity of cooling system, the heat dissipating capacity of surrounding rock and air temperature change. Then, the heat absorption capacity required by air temperature less than the standard value for safety is figured out by section iterative method with the simultaneous solution of heat absorption control equation and the heat dissipation density equation of surrounding rock. Finally, the results show that as the air temperature at the inlet of roadway is 25 ℃, the roadway wall is covered by heat-absorbing plate up to 39% of the area, as well as the cold water is injected into the heat-absorbing plate with a temperature of 20 ℃ and a mass flow of 113.6 kg/s, the air flow temperature rise per kilometer in the roadway can be less than 3 ℃.展开更多
This study seeks to determine an effective boundary between government and market in light of modern financial theories.According to the findings of this paper,the relationship between government and market must be co...This study seeks to determine an effective boundary between government and market in light of modern financial theories.According to the findings of this paper,the relationship between government and market must be conceived of as under the "continuous spectrum of change" resulting from economic development.In practice,an effective frontier between government and market not only transforms continuously with the process of economic development but also demonstrates significant contrasts internationally according to the different national characteristics existing in each country.Determining a frontier between government and market requires that the relationship between the two be embedded into a broader set of institutional environmental constraints that incorporate consideration of the dynamic processes and mechanisms of economic development.The key issue is that government and market act with regard to the principle of comparative advantage as they play their respective roles.展开更多
Heat and mass transfer analysis of an incompressible, laminar boundary layer over solar flat plate collector evapora- tion systems for tannery effluent (soak liquor) is investigated. The governing equations are solved...Heat and mass transfer analysis of an incompressible, laminar boundary layer over solar flat plate collector evapora- tion systems for tannery effluent (soak liquor) is investigated. The governing equations are solved for various liquid to air velocity ratios. Profiles of velocity, temperature and concentration as well as their gradients are presented. The heat transfer and mass transfer coefficients thus obtained are used to evaluate mass of water evaporated for an inclined fibre-reinforced plastic (FRP) solar flat plate collector (FPC) with and without cover. Comparison of these results with the experimental performance shows encouraging trend of good agreement between them.展开更多
This paper first explores the concepts of values and ethics, utilizing a social work framework. It proceeds to examine various dilemmas involved in communicating with others via social media tools. Historic boundary i...This paper first explores the concepts of values and ethics, utilizing a social work framework. It proceeds to examine various dilemmas involved in communicating with others via social media tools. Historic boundary issues between students and faculty are discussed, as well as emerging dilemmas that are becoming prevalent within electronic communicative networks （e.g., Skype, Facebook, Myspace, Linkedln, Twitter, and Texting）. The need for policy guidelines within academic environments in the use of social media is emphasized, Similar to the National Association of Social Workers （NASW） Code of Ethics, Arizona State University （ASU） is cited as a model in providing some structure regarding staff responsibility and unethical conduct within its academic setting. An enhancement of these guidelines to include electronic communication is recommended. Guidance is necessary to promote responsible communication, as the right to privacy, freedom of speech, and anonymity are all illusions of invulnerability.展开更多
基金National Natural Science Foundation of China(40645026)National Basic Research Programof China (2002CB410801)
文摘Based on the geographical circumstance, climate and the boundary layer meteorology features of the Pearl River Delta, a boundary layer concept model of the Pearl River Delta was built. The concept model consists of four fundamental factors that affect the boundary layer meteorology of the Pearl River Delta and can convincingly explain the reason of the air quality change in the Pearl River Delta. The model can be used to the diffusion capability analysis, the air pollution potential forecasting or haze forecasting, etc.
文摘Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issues in hydrometallurgical cut-off grades determination. Slags are remarked as one of the main sources of copper. It is not only regarded as a waste but also identified as another resource extracting base metals. Slags are characterized by copper high grade. Thus, slag copper recovery can be led to different cut-off grades and net present value(NPV). The current research scrutinizes the effect of slag recovery by both flotation and hydrometallurgical methods on the hydrometallurgical cut-off grades. For this purpose, the optimum cut-off grade algorithms of hydrometallurgical methods are developed by considering associated environmental parameters, incomes and also the costs. Then, their optimum amounts are calculated with NPV maximization as an objective function. The results indicate that considering slag copper recovery in the hydrometallurgical cut-off grade algorithms reduces the environmental costs caused by slag dumping and leads to more NPV by 9%.
基金Project(2018CXNL08) supported by the Fundamental Research Funds for the Central Universities,China。
文摘In order to solve the heat damages in deep mines, a cool-wall cooling technology and its working model are proposed based on the principles of heat absorption and insulation in this paper. During this process, the differential equation of thermal equilibrium for roadway control unit is built, and the heat adsorption control equation of cool-wall cooling system is derived by an integral method, so as to obtain the quantitative relationship among the heat absorption capacity of cooling system, the heat dissipating capacity of surrounding rock and air temperature change. Then, the heat absorption capacity required by air temperature less than the standard value for safety is figured out by section iterative method with the simultaneous solution of heat absorption control equation and the heat dissipation density equation of surrounding rock. Finally, the results show that as the air temperature at the inlet of roadway is 25 ℃, the roadway wall is covered by heat-absorbing plate up to 39% of the area, as well as the cold water is injected into the heat-absorbing plate with a temperature of 20 ℃ and a mass flow of 113.6 kg/s, the air flow temperature rise per kilometer in the roadway can be less than 3 ℃.
基金supported by National Natural Science Foundation of China(Grant No.71403277)National Social Science Foundation of China(Grant No.12&ZD089)
文摘This study seeks to determine an effective boundary between government and market in light of modern financial theories.According to the findings of this paper,the relationship between government and market must be conceived of as under the "continuous spectrum of change" resulting from economic development.In practice,an effective frontier between government and market not only transforms continuously with the process of economic development but also demonstrates significant contrasts internationally according to the different national characteristics existing in each country.Determining a frontier between government and market requires that the relationship between the two be embedded into a broader set of institutional environmental constraints that incorporate consideration of the dynamic processes and mechanisms of economic development.The key issue is that government and market act with regard to the principle of comparative advantage as they play their respective roles.
文摘Heat and mass transfer analysis of an incompressible, laminar boundary layer over solar flat plate collector evapora- tion systems for tannery effluent (soak liquor) is investigated. The governing equations are solved for various liquid to air velocity ratios. Profiles of velocity, temperature and concentration as well as their gradients are presented. The heat transfer and mass transfer coefficients thus obtained are used to evaluate mass of water evaporated for an inclined fibre-reinforced plastic (FRP) solar flat plate collector (FPC) with and without cover. Comparison of these results with the experimental performance shows encouraging trend of good agreement between them.
文摘This paper first explores the concepts of values and ethics, utilizing a social work framework. It proceeds to examine various dilemmas involved in communicating with others via social media tools. Historic boundary issues between students and faculty are discussed, as well as emerging dilemmas that are becoming prevalent within electronic communicative networks （e.g., Skype, Facebook, Myspace, Linkedln, Twitter, and Texting）. The need for policy guidelines within academic environments in the use of social media is emphasized, Similar to the National Association of Social Workers （NASW） Code of Ethics, Arizona State University （ASU） is cited as a model in providing some structure regarding staff responsibility and unethical conduct within its academic setting. An enhancement of these guidelines to include electronic communication is recommended. Guidance is necessary to promote responsible communication, as the right to privacy, freedom of speech, and anonymity are all illusions of invulnerability.
