Livelihood of the people in Nepal hills depends much upon forest resources in addition to farming as forest plays a critical role in the well being of the farming households where access to alternative sources, such a...Livelihood of the people in Nepal hills depends much upon forest resources in addition to farming as forest plays a critical role in the well being of the farming households where access to alternative sources, such as energy for cooking, nutrition for animals, materials for fertilizer and constructing materials for shelter, are limited. Thus, the well being of the people in the hills is directly affected by the management of these forest resources. This issue was addressed in this paper by examining the forest resource management practices and its effect on well being of rural people in two different stages in a village lying in the steep hill of Mahabharat Range in the southern hills of Kathmandu valley, Lalitpur District. The main ethnic/caste groups in the village are Brahmin/Chhetri (high Hindu caste), Magar/Tamang (Tibeto Burmans) and Kami (occupational caste: cobbler). Currently there are four community forest users groups, with mixed ethnic membership, organized to manage the forest resources. The endowments, weak institutional settings, before 1990 helped the Bhramins, Magars and Tamangs to get access into the private forest endowment, which made them easy to get access to the forest resources, mainly fuel wood, fodder and timber in 1990 and enhanced their well beings. But the socially backward Kami could not get benefit from the institutions that existed during that time and had less chance to enhance their well beings. After the set up of different endowments during late 1990s, i.e., hand over of forest management to usersgroupsin line with the concept of community forest, environment to use the forest resources became better for all the groups, along with the management of the forest. This enhanced the well beings of all the groups in the study village. However, the ability of Kami to use the forest resources to enhance their well beings was still lacking behind. The reason was partially due to the difference in endowments carried over from the endowments before 1990, and partly due to their occupational work and location of their settlements.展开更多
Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of ...Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of urban areas. With a comparative study of international experiences, this article analyzed the mechanism and consequences of urban expansion, reviewed the typical planning and financial policies adopted by other countries for controlling urban sprawl, and discussed the suitable densities of urban areas. The analysis results suggested that Chinese cities have no better choice but compact urban forms. To achieve the goal of compact development, intensive use of public transportation and high proportion of collective houses should be encouraged, and 60–100 m2 per capita is recommended as the reasonable range of urban density in large cities.展开更多
The reform of the system of water resource management abroad has started since the 50s of last century, it has left us a lot of experiences in many aspects with the innovation of system, such as the legal environment ...The reform of the system of water resource management abroad has started since the 50s of last century, it has left us a lot of experiences in many aspects with the innovation of system, such as the legal environment in water resources, water rights, water market theory, and the ＂participation＂ management of water resources, these experiences has been promoted in more than 40 developing countries. Based on analyzing the theory and experiences of water resources management both at home and abroad, especially the theory and experiences of agricultural water resources management, this paper puts forward the main problems waiting for further investigation in China＇s water resources management and provides some reference and inspiration for the innovation of the system of water resource management in China.展开更多
The tendency for air column resonance generation in structures with a constant volume behind a tube array like that of an exhaust gas economizer has been reported, but many points remain unclear with respect to the me...The tendency for air column resonance generation in structures with a constant volume behind a tube array like that of an exhaust gas economizer has been reported, but many points remain unclear with respect to the mechanism and conditions that generate acoustical resonance. When acoustical resonance is generated, in reality, prevention and suppression measures are implemented by inserting a baffle plate into the ducts through a process of trial and error. The purpose of this study is to clarify the mechanism of generation of acoustical resonance, and to establish an appropriate measure to prevent such resonance. Noise generated in an exhaust gas economizer was correlated with the flow inside the tube array and experimentally analyzed, and the mechanism for resonance generation was considered. In addition, the effectiveness of a baffle plate positioned in order to prevent resonance was investigated. We have successfully employed a single baffle plate to suppress resonance.展开更多
Circuit module structure and function of high and low voltage for a pure electric road sweeper were depicted, and the necessity of energy management system was discussed. Based on preliminary research of battery life-...Circuit module structure and function of high and low voltage for a pure electric road sweeper were depicted, and the necessity of energy management system was discussed. Based on preliminary research of battery life-span, some factors that affect battery use in group and reasonable scope of battery SOC were given. The test results of the pure electric road sweeper show that its performance is reliable and operation cost is low. It is possible to replace the conventional sanitation vehicle in the future. The successful experience of the pure electric road sweeper is significantly recommendable for the future development of electric vehicle （EV）.展开更多
文摘Livelihood of the people in Nepal hills depends much upon forest resources in addition to farming as forest plays a critical role in the well being of the farming households where access to alternative sources, such as energy for cooking, nutrition for animals, materials for fertilizer and constructing materials for shelter, are limited. Thus, the well being of the people in the hills is directly affected by the management of these forest resources. This issue was addressed in this paper by examining the forest resource management practices and its effect on well being of rural people in two different stages in a village lying in the steep hill of Mahabharat Range in the southern hills of Kathmandu valley, Lalitpur District. The main ethnic/caste groups in the village are Brahmin/Chhetri (high Hindu caste), Magar/Tamang (Tibeto Burmans) and Kami (occupational caste: cobbler). Currently there are four community forest users groups, with mixed ethnic membership, organized to manage the forest resources. The endowments, weak institutional settings, before 1990 helped the Bhramins, Magars and Tamangs to get access into the private forest endowment, which made them easy to get access to the forest resources, mainly fuel wood, fodder and timber in 1990 and enhanced their well beings. But the socially backward Kami could not get benefit from the institutions that existed during that time and had less chance to enhance their well beings. After the set up of different endowments during late 1990s, i.e., hand over of forest management to usersgroupsin line with the concept of community forest, environment to use the forest resources became better for all the groups, along with the management of the forest. This enhanced the well beings of all the groups in the study village. However, the ability of Kami to use the forest resources to enhance their well beings was still lacking behind. The reason was partially due to the difference in endowments carried over from the endowments before 1990, and partly due to their occupational work and location of their settlements.
基金supported by Natural Science Foundation of China (Grant no. 40671063)
文摘Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of urban areas. With a comparative study of international experiences, this article analyzed the mechanism and consequences of urban expansion, reviewed the typical planning and financial policies adopted by other countries for controlling urban sprawl, and discussed the suitable densities of urban areas. The analysis results suggested that Chinese cities have no better choice but compact urban forms. To achieve the goal of compact development, intensive use of public transportation and high proportion of collective houses should be encouraged, and 60–100 m2 per capita is recommended as the reasonable range of urban density in large cities.
文摘The reform of the system of water resource management abroad has started since the 50s of last century, it has left us a lot of experiences in many aspects with the innovation of system, such as the legal environment in water resources, water rights, water market theory, and the ＂participation＂ management of water resources, these experiences has been promoted in more than 40 developing countries. Based on analyzing the theory and experiences of water resources management both at home and abroad, especially the theory and experiences of agricultural water resources management, this paper puts forward the main problems waiting for further investigation in China＇s water resources management and provides some reference and inspiration for the innovation of the system of water resource management in China.
文摘The tendency for air column resonance generation in structures with a constant volume behind a tube array like that of an exhaust gas economizer has been reported, but many points remain unclear with respect to the mechanism and conditions that generate acoustical resonance. When acoustical resonance is generated, in reality, prevention and suppression measures are implemented by inserting a baffle plate into the ducts through a process of trial and error. The purpose of this study is to clarify the mechanism of generation of acoustical resonance, and to establish an appropriate measure to prevent such resonance. Noise generated in an exhaust gas economizer was correlated with the flow inside the tube array and experimentally analyzed, and the mechanism for resonance generation was considered. In addition, the effectiveness of a baffle plate positioned in order to prevent resonance was investigated. We have successfully employed a single baffle plate to suppress resonance.
文摘Circuit module structure and function of high and low voltage for a pure electric road sweeper were depicted, and the necessity of energy management system was discussed. Based on preliminary research of battery life-span, some factors that affect battery use in group and reasonable scope of battery SOC were given. The test results of the pure electric road sweeper show that its performance is reliable and operation cost is low. It is possible to replace the conventional sanitation vehicle in the future. The successful experience of the pure electric road sweeper is significantly recommendable for the future development of electric vehicle （EV）.
