Abstract Elements and natural radionuclides in the contact zone of two granites with different ages would migrate from one to the other because of the difference in their chemical contents and later water-rock interac...Abstract Elements and natural radionuclides in the contact zone of two granites with different ages would migrate from one to the other because of the difference in their chemical contents and later water-rock interactions. This migration could serve as an analogue for the near-field process of radwastes in a high-level radwaste deep geological disposal repository.展开更多
Blasting used for rock excavation is associated with ground vibrations having potential damage to surrounding structures.The extent of damage produced in a structure depends largely on ground motion characteristics,dy...Blasting used for rock excavation is associated with ground vibrations having potential damage to surrounding structures.The extent of damage produced in a structure depends largely on ground motion characteristics,dynamic characteristics of structure and the type of geological strata on which it is founded.The safety of surrounding structures against blast vibrations is a cause of concern.However,use of a systematic approach to rock blasting helps to complete the excavation safely in time without endangering the safety of surrounding structures.Various steps are commonly adopted at construction sites to ensure safety of engineered structures against blast vibrations,e.g.adopting a suitable safe vibration level,developing site-specific attenuation relation,estimating safe charges for different distances,designing blasting pattern,and monitoring vibrations during actual blasting.The paper describes the details of studies conducted for ensuring safety of an 85 years old masonry dam and green concrete of varying ages during excavation of about 30,000 m;of hard rock in Maharashtra,India.The studies helped to complete the rock excavation safely in time and the safety of the dam was ensured by monitoring blast vibrations during actual rock excavation.展开更多
It is always quite difficult to accurately measure boiler drum water level in power plant. Though the effect of false measurement of water level can be reduced with some devices, the effect of deviation of boiler drum...It is always quite difficult to accurately measure boiler drum water level in power plant. Though the effect of false measurement of water level can be reduced with some devices, the effect of deviation of boiler drum water level to the monitoring and alarm system, even to the control of drum water level, and so on, cannot be surmounted. Because of these reasons, the accurate water level alarm signal cannot be provided and the water level control measures cannot be applied. In order to solve this problem, a water level deviation analysis method is presented for analyzing boiler drum water level. Based on the analysis of boiler drum water level related running parameters, the relational model of water level deviation under different working conditions and its parameters is constructed. By analyzing this model, the specific impacts of the main factors can be fixed. Thus the drum water level deviation can be reduced by adjusting running parameters without changing unit load. And then the measurement of drum water level can be more accurate only if power plants have accurate measuring devices. Therefore, the boiler drum water level can be more accurately monitored and controlled. So, this innovation is important in ensuring the safe running of power plant.展开更多
文摘Abstract Elements and natural radionuclides in the contact zone of two granites with different ages would migrate from one to the other because of the difference in their chemical contents and later water-rock interactions. This migration could serve as an analogue for the near-field process of radwastes in a high-level radwaste deep geological disposal repository.
文摘Blasting used for rock excavation is associated with ground vibrations having potential damage to surrounding structures.The extent of damage produced in a structure depends largely on ground motion characteristics,dynamic characteristics of structure and the type of geological strata on which it is founded.The safety of surrounding structures against blast vibrations is a cause of concern.However,use of a systematic approach to rock blasting helps to complete the excavation safely in time without endangering the safety of surrounding structures.Various steps are commonly adopted at construction sites to ensure safety of engineered structures against blast vibrations,e.g.adopting a suitable safe vibration level,developing site-specific attenuation relation,estimating safe charges for different distances,designing blasting pattern,and monitoring vibrations during actual blasting.The paper describes the details of studies conducted for ensuring safety of an 85 years old masonry dam and green concrete of varying ages during excavation of about 30,000 m;of hard rock in Maharashtra,India.The studies helped to complete the rock excavation safely in time and the safety of the dam was ensured by monitoring blast vibrations during actual rock excavation.
基金supported by the State Key Program of National Natural Science Foundation of China(No.61034004)Shanghai Science and Technology Commission Key Program(Nos.14DZ2251100,15510722100 and 15111106800)Shanghai Key Laboratory of Power Station Automation Technology(No.13DZ2273800)
文摘It is always quite difficult to accurately measure boiler drum water level in power plant. Though the effect of false measurement of water level can be reduced with some devices, the effect of deviation of boiler drum water level to the monitoring and alarm system, even to the control of drum water level, and so on, cannot be surmounted. Because of these reasons, the accurate water level alarm signal cannot be provided and the water level control measures cannot be applied. In order to solve this problem, a water level deviation analysis method is presented for analyzing boiler drum water level. Based on the analysis of boiler drum water level related running parameters, the relational model of water level deviation under different working conditions and its parameters is constructed. By analyzing this model, the specific impacts of the main factors can be fixed. Thus the drum water level deviation can be reduced by adjusting running parameters without changing unit load. And then the measurement of drum water level can be more accurate only if power plants have accurate measuring devices. Therefore, the boiler drum water level can be more accurately monitored and controlled. So, this innovation is important in ensuring the safe running of power plant.
