It is introduced the current situation and development for solar heating technology including passive solar heating and solar heating combisystems in China in this paper. Combined with the engineering application proj...It is introduced the current situation and development for solar heating technology including passive solar heating and solar heating combisystems in China in this paper. Combined with the engineering application projects, the author gave the technical and economic analysis of the passive solar and solar heating combisystems in China and summarized the developing obstacle and the spreading tactics for raising marketing of the solar heating in China.展开更多
The hydrothermal scheduling in the electric power market becomes difficult because of introducing competition and considering sorts of constraints. An augmented Lagrangian approach is adopted to solve the problem,whic...The hydrothermal scheduling in the electric power market becomes difficult because of introducing competition and considering sorts of constraints. An augmented Lagrangian approach is adopted to solve the problem,which adds to the standard Lagrangian function a quadratic penalty term without changing its dual property,and reduces the oscillation in iterations. According to the theory of large system coordination and decomposition,the problem is divided into hydro sub-problem and thermal sub-problem,which are coordinated by updating the Lagrangian multipliers,then the optimal solution is obtained. Our results for a test system show that the augmented Lagrangian approach can make the problem converge into the optimal solution quickly.展开更多
The objective of the study was to assess factors affecting market participation of agro-forestry smallholder farmers in Uganda. Primary data on household, farm and marketing characteristics were collected from 153 far...The objective of the study was to assess factors affecting market participation of agro-forestry smallholder farmers in Uganda. Primary data on household, farm and marketing characteristics were collected from 153 farming households using a semi-structured, pre-tested questionnaire. The determinants of market participation were assessed using the Probit model. Descriptive statistics showed that a combination of crop, livestock and tree products were marketed by farmers. The main products included maize, cassava and coffee （crops）; firewood and poles （tree products）; and birds and goats （livestock products）. Results from the Probit model showed that farm size, household size, education level, access to credit and extension visits had positive and statistically significant effects on market participation of farmers in agro-forestry products＇ markets. Age of farmer had a negative and statistically significant effect on the participation. Emphasis on improving the quality and coverage of extension services, extending credit facilities to farmers and intensifying agro-forestry training among farmers are suggested as avenues to enhance participation of farmers in agro-forestry products＇ markets.展开更多
The state-of-the-art solar power system technologies are presented. Various methods of capturing solar energy using solar collectors such as parabolic trough collectors and dish collectors are reviewed. Combined heat ...The state-of-the-art solar power system technologies are presented. Various methods of capturing solar energy using solar collectors such as parabolic trough collectors and dish collectors are reviewed. Combined heat and power （CHP） systems driven by concentrating solar absorbers and supplemented by biomass boilers are proving to be the most promising methods of domestic power generation, μCHP systems eliminate losses associated with power distribution and transmission opposed to the large scale power generation methods. The systems can utilize about 75% of solar energy to provide electric and thermal energy direct to end users. The driving potential behind μCHP systems is the thermal efficiency the systems can achieve and their market significance. Despite huge potential market for μCHP systems, the systems are yet to be seen available in commercial market. Hence the authors of this paper are currently developing such type of CHP system with electricity production being of prime importance.展开更多
文摘It is introduced the current situation and development for solar heating technology including passive solar heating and solar heating combisystems in China in this paper. Combined with the engineering application projects, the author gave the technical and economic analysis of the passive solar and solar heating combisystems in China and summarized the developing obstacle and the spreading tactics for raising marketing of the solar heating in China.
基金the Specialized Research Fund for the Doctoral Program of High Education(Grant No.20050213006) the Key Science Research Project of Heilongjiang Province(Grant No.GD07A304).
文摘The hydrothermal scheduling in the electric power market becomes difficult because of introducing competition and considering sorts of constraints. An augmented Lagrangian approach is adopted to solve the problem,which adds to the standard Lagrangian function a quadratic penalty term without changing its dual property,and reduces the oscillation in iterations. According to the theory of large system coordination and decomposition,the problem is divided into hydro sub-problem and thermal sub-problem,which are coordinated by updating the Lagrangian multipliers,then the optimal solution is obtained. Our results for a test system show that the augmented Lagrangian approach can make the problem converge into the optimal solution quickly.
文摘The objective of the study was to assess factors affecting market participation of agro-forestry smallholder farmers in Uganda. Primary data on household, farm and marketing characteristics were collected from 153 farming households using a semi-structured, pre-tested questionnaire. The determinants of market participation were assessed using the Probit model. Descriptive statistics showed that a combination of crop, livestock and tree products were marketed by farmers. The main products included maize, cassava and coffee （crops）; firewood and poles （tree products）; and birds and goats （livestock products）. Results from the Probit model showed that farm size, household size, education level, access to credit and extension visits had positive and statistically significant effects on market participation of farmers in agro-forestry products＇ markets. Age of farmer had a negative and statistically significant effect on the participation. Emphasis on improving the quality and coverage of extension services, extending credit facilities to farmers and intensifying agro-forestry training among farmers are suggested as avenues to enhance participation of farmers in agro-forestry products＇ markets.
文摘The state-of-the-art solar power system technologies are presented. Various methods of capturing solar energy using solar collectors such as parabolic trough collectors and dish collectors are reviewed. Combined heat and power （CHP） systems driven by concentrating solar absorbers and supplemented by biomass boilers are proving to be the most promising methods of domestic power generation, μCHP systems eliminate losses associated with power distribution and transmission opposed to the large scale power generation methods. The systems can utilize about 75% of solar energy to provide electric and thermal energy direct to end users. The driving potential behind μCHP systems is the thermal efficiency the systems can achieve and their market significance. Despite huge potential market for μCHP systems, the systems are yet to be seen available in commercial market. Hence the authors of this paper are currently developing such type of CHP system with electricity production being of prime importance.
