The theoretical research of cable-driven mechanisms is developed with its broad applications. The first prototype of cable-driven mechanisms is RoboCrane, which was developed by the National Institute of Standards and...The theoretical research of cable-driven mechanisms is developed with its broad applications. The first prototype of cable-driven mechanisms is RoboCrane, which was developed by the National Institute of Standards and Technology (NIST). Then many excellent properties were developed and they have a variety of applications such as aerospace, aircraft and automobile industries [1]. Example application for RoboCrane in the field of aircraft mainte- nance is equipped with a quick-change mechanism to remove the robot arm remotely.展开更多
Agricultural tridimensional pollution (AtriP) has multi-directional and complicated chains. Circular economy is found to be an efficient mechanism that can help control AtriP. The application of three circular econo...Agricultural tridimensional pollution (AtriP) has multi-directional and complicated chains. Circular economy is found to be an efficient mechanism that can help control AtriP. The application of three circular economic modes in agriculture and its related industries call not only interdict the AtriP chains in different stages and different directions, but also produce greater ecological, social and economical returns with less input. Nevertheless, it is a complicated systematic engineering to construct and implement effective circular economic modes to bring AtriP under control, and it depends not only on the support of the relevant technology system, but also on the supports of the relevant policies and law systems.展开更多
Based on the analyses of data obtained from the underground powerhouse at Jinping I hydropower station, a comprehensive review of engineering rock mechanics practice in the underground powerhouse is first conducted. T...Based on the analyses of data obtained from the underground powerhouse at Jinping I hydropower station, a comprehensive review of engineering rock mechanics practice in the underground powerhouse is first conducted. The distribution of strata, lithology, and initial geo-stress, the excavation process and corresponding rock mass support measures, the deformation and failure characteristics of the surrounding rock mass, the stress characteristics of anchorage structures in the cavern complex, and numerical simulations of surrounding rock mass stability and anchor support performance are presented. The results indicate that the underground powerhouse of Jinping I hydropower station is characterized by high to extremely high geo-stresses during rock excavation. Excessive surrounding rock mass deformation and high stress of anchorage structures, surrounding rock mass unloading damage, and local cracking failure of surrounding rock masses, etc., are mainly caused by rock mass excavation. Deformations of surrounding rock masses and stresses in anchorage structures here are larger than those found elsewhere: 20% of extensometers in the main powerhouse record more than 50 mm with the maximum at around 250 mm observed in the downstream sidewall of the transformer hall. There are about 25% of the anchor bolts having recorded stresses of more than 200 MPa. Jinping I hydropower plant is the first to have an underground powerhouse construction conducted in host rocks under extremely high geo-stress conditions, with the ratio of rock mass strength to geo-stress of less than 2.0. The results can provide a reference to underground powerhouse construction in similar geological conditions.展开更多
In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic co...In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic compounds have frequently been detected, sometimes at high concentrations, particularly at sites abandoned by chemical manufacturing enterprises. With the redevelopment of sites and changes in land-use tvpe associated with these sites, substantial amounts of contaminated soils now require remediation. "Since China is a developing country, soil remediation warrants the usage of techniques that are suitable for addressing the unique challenges faced in this country. Land shortage is a common problem in China; the large numbers of contaminated sites, tight development schedules, and limited financial resources necessitate the development of .cost-effective methods for land reclamation.Mechanical soil aeration is a simple, effective, and low-cost soil remediation tectm^que mat is particularly suitable for the remediation of large volatile organic compound-contaminated sites. Its effectiveness has been confirmed by conducting laboratory studies, pilot tests, and full-scale projects.This study reviews current engineei-ing practice and developmental trends of mechanical soil aeration and analyzes the advantages and disadvantages of this technology for application in China as an emerging soil remediation market. The findings of this study might aid technology development in China, as well as assist other developing countries in the assessment and implementation of costeffective hazardous waste site soil remediation programs.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51575150)
文摘The theoretical research of cable-driven mechanisms is developed with its broad applications. The first prototype of cable-driven mechanisms is RoboCrane, which was developed by the National Institute of Standards and Technology (NIST). Then many excellent properties were developed and they have a variety of applications such as aerospace, aircraft and automobile industries [1]. Example application for RoboCrane in the field of aircraft mainte- nance is equipped with a quick-change mechanism to remove the robot arm remotely.
文摘Agricultural tridimensional pollution (AtriP) has multi-directional and complicated chains. Circular economy is found to be an efficient mechanism that can help control AtriP. The application of three circular economic modes in agriculture and its related industries call not only interdict the AtriP chains in different stages and different directions, but also produce greater ecological, social and economical returns with less input. Nevertheless, it is a complicated systematic engineering to construct and implement effective circular economic modes to bring AtriP under control, and it depends not only on the support of the relevant technology system, but also on the supports of the relevant policies and law systems.
基金the valuable support from Yalong River Hydropower Development Company,Ltd.HydroChina Chengdu Engineering Corporation,Ltdthe National Natural Science Foundation of China(Grant Nos.51179014,51579016,51379022,and 51539002)
文摘Based on the analyses of data obtained from the underground powerhouse at Jinping I hydropower station, a comprehensive review of engineering rock mechanics practice in the underground powerhouse is first conducted. The distribution of strata, lithology, and initial geo-stress, the excavation process and corresponding rock mass support measures, the deformation and failure characteristics of the surrounding rock mass, the stress characteristics of anchorage structures in the cavern complex, and numerical simulations of surrounding rock mass stability and anchor support performance are presented. The results indicate that the underground powerhouse of Jinping I hydropower station is characterized by high to extremely high geo-stresses during rock excavation. Excessive surrounding rock mass deformation and high stress of anchorage structures, surrounding rock mass unloading damage, and local cracking failure of surrounding rock masses, etc., are mainly caused by rock mass excavation. Deformations of surrounding rock masses and stresses in anchorage structures here are larger than those found elsewhere: 20% of extensometers in the main powerhouse record more than 50 mm with the maximum at around 250 mm observed in the downstream sidewall of the transformer hall. There are about 25% of the anchor bolts having recorded stresses of more than 200 MPa. Jinping I hydropower plant is the first to have an underground powerhouse construction conducted in host rocks under extremely high geo-stress conditions, with the ratio of rock mass strength to geo-stress of less than 2.0. The results can provide a reference to underground powerhouse construction in similar geological conditions.
文摘In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic compounds have frequently been detected, sometimes at high concentrations, particularly at sites abandoned by chemical manufacturing enterprises. With the redevelopment of sites and changes in land-use tvpe associated with these sites, substantial amounts of contaminated soils now require remediation. "Since China is a developing country, soil remediation warrants the usage of techniques that are suitable for addressing the unique challenges faced in this country. Land shortage is a common problem in China; the large numbers of contaminated sites, tight development schedules, and limited financial resources necessitate the development of .cost-effective methods for land reclamation.Mechanical soil aeration is a simple, effective, and low-cost soil remediation tectm^que mat is particularly suitable for the remediation of large volatile organic compound-contaminated sites. Its effectiveness has been confirmed by conducting laboratory studies, pilot tests, and full-scale projects.This study reviews current engineei-ing practice and developmental trends of mechanical soil aeration and analyzes the advantages and disadvantages of this technology for application in China as an emerging soil remediation market. The findings of this study might aid technology development in China, as well as assist other developing countries in the assessment and implementation of costeffective hazardous waste site soil remediation programs.