It has been proven by a number of earthquake case studies that an active fault-induced earthquake beneath a city can be devastating. It is an urgent issue for seismic hazard reduction to explore the distribution of ac...It has been proven by a number of earthquake case studies that an active fault-induced earthquake beneath a city can be devastating. It is an urgent issue for seismic hazard reduction to explore the distribution of active faults beneath the urban area and identify the seismic source and the risks underneath. As a pilot project of active fault exploration in China, the project, entitled “Active fault exploration and seismic hazard assessment in Fuzhou City”, started in early 2001 and passed the check before acceptance of China Earthquake Administration in August 2004. The project was aimed to solve a series of scientific issues such as fault location, dating, movement nature, deep settings, seismic risk and hazard, preparedness of earthquake prevention and disaster reduction, and etc. by means of exploration and assessment of active faults by stages, i.e., the preliminary survey and identification of active faults in target area, the exploration of deep seismotectonic settings, the risk evaluation of active seismogenic faults, the construction of geographic information system of active faults, and so on. A lot of exploration methods were employed in the project such as the detection of absorbed mercury, free mercury and radon in soil, the geological radar, multi-channel DC electrical method, tsansient electromagnetic method, shallow seismic refraction and reflection, effect contrast of explored sources, and various sounding experiments, to establish the buried Quaternary standard section of the Fuzhou basin. By summing up, the above explorations and experiments have achieved the following results and conclusions ：展开更多
Active networks is primarily a Defense Advanced Research Projects Agency(DARPA)-funded project focusing on the research of mechanisms, applications, and operating systems to develop a reconfigurable network infrastruc...Active networks is primarily a Defense Advanced Research Projects Agency(DARPA)-funded project focusing on the research of mechanisms, applications, and operating systems to develop a reconfigurable network infrastructure. This letter proposes an Secure Active Tracing System (SATS) to implementing security for active networking in Internet. Unlike currently existing schemes, SATS reduces the computational overloads by executing the filtering operation on selected packet streams only when needed.展开更多
Based on the collection and analysis of achievements of other scholars, and by consulting the results of seismic safety evaluation of engineering sites and field surveys of recent years, the seismotectonic indicators ...Based on the collection and analysis of achievements of other scholars, and by consulting the results of seismic safety evaluation of engineering sites and field surveys of recent years, the seismotectonic indicators are determined for northwest Yunnan and its vicinity, and then potential seismic sources are further delineated. In practice, the following principles are applied: for areas with strong historical earthquakes, the recurrence principle is used to determine the upper bound magnitude; for areas with distinct seismogenic structure but no historical strong earthquake records, the tectonic analogy principle is used in the light of the size and activity behavior of the structure; for areas where the segmentation of the active fault is well studied, the potential sources will be demarcated more precisely; and for areas with buried fault, the seismicity pattern and geophysical abnormity are used to determine the direction of the major axis of the potential seismic source.展开更多
Long-line engineering sites usually have to pass through active tectonics, so the research of active tectonics is of great importance to seismic safety evaluation of this sort of site. In the paper, basing on the summ...Long-line engineering sites usually have to pass through active tectonics, so the research of active tectonics is of great importance to seismic safety evaluation of this sort of site. In the paper, basing on the summarization and analysis of the requirements for seismic safety evaluation of long-line engineering site and the status quo of active tectonics research, we propose the focal points of active tectonics research for seismic safety evaluation of long-line engineering sites, including the research contents, technical targets and routes, and the submission of the achievements, etc. Finally, we make a preliminary analysis and discussion about the problems existing in the present-day active tectonics research for seismic safety evaluation of long-line engineering sites.展开更多
The present article examines the livelihood benefits associated with agrobiodiversity in Veracruz, Mexico. Citrus-based agriculture is the principal economic activity in the agricultural sector of the state of Veracru...The present article examines the livelihood benefits associated with agrobiodiversity in Veracruz, Mexico. Citrus-based agriculture is the principal economic activity in the agricultural sector of the state of Veracruz. It is practiced in mono-crop plantations by the majority of farmers, who are rendered vulnerable to price depreciation resulting from simultaneous harvest and over-supply of a single commodity. Some farmers have associated multiple crops in citrus farms （agroforestry techniques） as a strategy to improve their livelihoods. Farmers who increased agrobiodiversity in their farms have significantly improved their livelihoods compared to mono-crop plantation owners. The research shows that increased agro-biodiversity can be a strategy to improve the livelihoods of citrus producers in the state of Veracruz, with significant economic benefits depending on the crop combination： maize-citrus is the least economically profitable combination （providing 21% in terms of internal rate of return）, while pineapple-citrus, banana-citrus and vanilla-citrus give higher returns （41%, 44% and 221% respectively）. The citrus-vanilla crop combination also has the highest benefit-cost ratio, relative to citrus monocrop （1.91） as well as the highest net present value （MX$579,635.73）. The choice of crop ultimately depends on the farmer＇s priorities. The associated benefits can be classified in three ways which correspond to the tripartite goal of sustainable development： （i） ecological sustainability （through increased ecosystem resilience）, （ii） economic stability （through diversified, less risk-prone sources of income）, and （iii） social well-being （through lower）.展开更多
文摘It has been proven by a number of earthquake case studies that an active fault-induced earthquake beneath a city can be devastating. It is an urgent issue for seismic hazard reduction to explore the distribution of active faults beneath the urban area and identify the seismic source and the risks underneath. As a pilot project of active fault exploration in China, the project, entitled “Active fault exploration and seismic hazard assessment in Fuzhou City”, started in early 2001 and passed the check before acceptance of China Earthquake Administration in August 2004. The project was aimed to solve a series of scientific issues such as fault location, dating, movement nature, deep settings, seismic risk and hazard, preparedness of earthquake prevention and disaster reduction, and etc. by means of exploration and assessment of active faults by stages, i.e., the preliminary survey and identification of active faults in target area, the exploration of deep seismotectonic settings, the risk evaluation of active seismogenic faults, the construction of geographic information system of active faults, and so on. A lot of exploration methods were employed in the project such as the detection of absorbed mercury, free mercury and radon in soil, the geological radar, multi-channel DC electrical method, tsansient electromagnetic method, shallow seismic refraction and reflection, effect contrast of explored sources, and various sounding experiments, to establish the buried Quaternary standard section of the Fuzhou basin. By summing up, the above explorations and experiments have achieved the following results and conclusions ：
文摘Active networks is primarily a Defense Advanced Research Projects Agency(DARPA)-funded project focusing on the research of mechanisms, applications, and operating systems to develop a reconfigurable network infrastructure. This letter proposes an Secure Active Tracing System (SATS) to implementing security for active networking in Internet. Unlike currently existing schemes, SATS reduces the computational overloads by executing the filtering operation on selected packet streams only when needed.
文摘Based on the collection and analysis of achievements of other scholars, and by consulting the results of seismic safety evaluation of engineering sites and field surveys of recent years, the seismotectonic indicators are determined for northwest Yunnan and its vicinity, and then potential seismic sources are further delineated. In practice, the following principles are applied: for areas with strong historical earthquakes, the recurrence principle is used to determine the upper bound magnitude; for areas with distinct seismogenic structure but no historical strong earthquake records, the tectonic analogy principle is used in the light of the size and activity behavior of the structure; for areas where the segmentation of the active fault is well studied, the potential sources will be demarcated more precisely; and for areas with buried fault, the seismicity pattern and geophysical abnormity are used to determine the direction of the major axis of the potential seismic source.
文摘Long-line engineering sites usually have to pass through active tectonics, so the research of active tectonics is of great importance to seismic safety evaluation of this sort of site. In the paper, basing on the summarization and analysis of the requirements for seismic safety evaluation of long-line engineering site and the status quo of active tectonics research, we propose the focal points of active tectonics research for seismic safety evaluation of long-line engineering sites, including the research contents, technical targets and routes, and the submission of the achievements, etc. Finally, we make a preliminary analysis and discussion about the problems existing in the present-day active tectonics research for seismic safety evaluation of long-line engineering sites.
文摘The present article examines the livelihood benefits associated with agrobiodiversity in Veracruz, Mexico. Citrus-based agriculture is the principal economic activity in the agricultural sector of the state of Veracruz. It is practiced in mono-crop plantations by the majority of farmers, who are rendered vulnerable to price depreciation resulting from simultaneous harvest and over-supply of a single commodity. Some farmers have associated multiple crops in citrus farms （agroforestry techniques） as a strategy to improve their livelihoods. Farmers who increased agrobiodiversity in their farms have significantly improved their livelihoods compared to mono-crop plantation owners. The research shows that increased agro-biodiversity can be a strategy to improve the livelihoods of citrus producers in the state of Veracruz, with significant economic benefits depending on the crop combination： maize-citrus is the least economically profitable combination （providing 21% in terms of internal rate of return）, while pineapple-citrus, banana-citrus and vanilla-citrus give higher returns （41%, 44% and 221% respectively）. The citrus-vanilla crop combination also has the highest benefit-cost ratio, relative to citrus monocrop （1.91） as well as the highest net present value （MX$579,635.73）. The choice of crop ultimately depends on the farmer＇s priorities. The associated benefits can be classified in three ways which correspond to the tripartite goal of sustainable development： （i） ecological sustainability （through increased ecosystem resilience）, （ii） economic stability （through diversified, less risk-prone sources of income）, and （iii） social well-being （through lower）.
