The physical and mechanical change processes of coal and rock are closely related to energy transformation,and the destruction and failure of coal and rock is an instability phenomena driven by energy change.However,t...The physical and mechanical change processes of coal and rock are closely related to energy transformation,and the destruction and failure of coal and rock is an instability phenomena driven by energy change.However,the energy change of large-scale coal rock in the mine site is hardly calculated accurately,making it difficult to monitor coal-rock systematic failure and collapse from the perspective of energy.By the energy dissipation EMR monitoring system,we studied the damage and failure of coal and rock with bursting liability from the energy dissipation point using the geophysical method-EMR,and explored the energy dissipation characteristics during uniaxial compression and their main influencing factors.The results show that under displacement-control loading mode,there are 2 types of energy dissipation trends for both coal and rock with bursting liability.The type Ⅰ trend is a steady increase one during the whole process,therein,the energy dissipation of rock samples is accelerated at the peak load.The type Ⅱ trend energy is a W-shaped fluctuating one containing 6 stages.Under load-control loading mode,there is one energy dissipation trend of shock downward-steady rise.Besides that,rock samples also present a trend of 4 stages.The energy dissipation characteristics of coal and rockduring loading failure process can be used as effective criteria to assess whether they are in a stable or destructive stage.The factors influencing energy dissipation in the loading failure process of coal and rock mainly include strength,homogeneity,and energy input efficiency.展开更多
Recycling is an alternative for preserving historical heritage buildings. Through such process, buildings are occupied by new usages that assure they are not abandoned. However, conservation issues, like pathological ...Recycling is an alternative for preserving historical heritage buildings. Through such process, buildings are occupied by new usages that assure they are not abandoned. However, conservation issues, like pathological manifestations by filamentous fungi, are common even in buildings receiving new uses. Thus, it is extremely important to know the microclimate behavior of these buildings and analyze if there are usages that favor the appearance of filamentous fungi or not. This study aims to verify if new usages modify the microclimate in historical buildings and if such possible change favors the appearance of pathological manifestations by filamentous fimgi in some specific use. To achieve the results, three buildings that have gone through recycling processes were chosen in the city of Pelotas, in Southernmost Brazil. The city possesses a large number of buildings with historical value and its climate conditions are propitious for appearance of filamentous fungi. For 12 months, microclimate was monitored, the environments modus operandi was characterized and there was a survey on the pathological manifestations by filamentous fungi in the three buildings with two different uses： administration offices and exhibition rooms. Conclusion was that usages that allow natural ventilation and lighting favor conservation, which is what happens in the ones used as administration offices. Besides that, it was noticed that the construction system also influences, since buildings with a high cellar that is being used did not present filamentous fungi, which also shows the influence of ascending humidity on the appearance of such pathological manifestations.展开更多
基金supported by Youth Science Foundation of the National Natural Science Foundation of China(No.51104156)the Fundamental Research Funds for the Central Universities of China(No.2013QNB02)the 12th Five Year National Science and Technology Support Key Project of China(Nos. 2012BAK04B07-2 and 2012BAK09B01-04)
文摘The physical and mechanical change processes of coal and rock are closely related to energy transformation,and the destruction and failure of coal and rock is an instability phenomena driven by energy change.However,the energy change of large-scale coal rock in the mine site is hardly calculated accurately,making it difficult to monitor coal-rock systematic failure and collapse from the perspective of energy.By the energy dissipation EMR monitoring system,we studied the damage and failure of coal and rock with bursting liability from the energy dissipation point using the geophysical method-EMR,and explored the energy dissipation characteristics during uniaxial compression and their main influencing factors.The results show that under displacement-control loading mode,there are 2 types of energy dissipation trends for both coal and rock with bursting liability.The type Ⅰ trend is a steady increase one during the whole process,therein,the energy dissipation of rock samples is accelerated at the peak load.The type Ⅱ trend energy is a W-shaped fluctuating one containing 6 stages.Under load-control loading mode,there is one energy dissipation trend of shock downward-steady rise.Besides that,rock samples also present a trend of 4 stages.The energy dissipation characteristics of coal and rockduring loading failure process can be used as effective criteria to assess whether they are in a stable or destructive stage.The factors influencing energy dissipation in the loading failure process of coal and rock mainly include strength,homogeneity,and energy input efficiency.
文摘Recycling is an alternative for preserving historical heritage buildings. Through such process, buildings are occupied by new usages that assure they are not abandoned. However, conservation issues, like pathological manifestations by filamentous fungi, are common even in buildings receiving new uses. Thus, it is extremely important to know the microclimate behavior of these buildings and analyze if there are usages that favor the appearance of filamentous fungi or not. This study aims to verify if new usages modify the microclimate in historical buildings and if such possible change favors the appearance of pathological manifestations by filamentous fimgi in some specific use. To achieve the results, three buildings that have gone through recycling processes were chosen in the city of Pelotas, in Southernmost Brazil. The city possesses a large number of buildings with historical value and its climate conditions are propitious for appearance of filamentous fungi. For 12 months, microclimate was monitored, the environments modus operandi was characterized and there was a survey on the pathological manifestations by filamentous fungi in the three buildings with two different uses： administration offices and exhibition rooms. Conclusion was that usages that allow natural ventilation and lighting favor conservation, which is what happens in the ones used as administration offices. Besides that, it was noticed that the construction system also influences, since buildings with a high cellar that is being used did not present filamentous fungi, which also shows the influence of ascending humidity on the appearance of such pathological manifestations.
