During the modernization or rehabilitation activity,the demolished structural waste causes large soil pollution and unavailability of natural aggregate is the big concern for the construction industry.Therefore,this m...During the modernization or rehabilitation activity,the demolished structural waste causes large soil pollution and unavailability of natural aggregate is the big concern for the construction industry.Therefore,this manuscript deals with the Composite Steel Circular Column(CSCC)with Recycled Aggregate concrete(RAC)as infill is partly used,with the replacement of 25%and 50%in M30 grade of Concrete.And internal reinforcement steel is fully replaced by rolled steel tubes(circular and square)with varied thickness,ISA-unequal angle.Around 14 specimens are cast and examined under axial load for analysis of the deflection characteristics,the load-bearing capacity along with its buckling behavior.The experimental values are estimated through LVDT(linear variable differential transducer)at 3-phase.The curve of load-deflection is drawn with the load pattern.From the date interpretation,it is found column made of 50%-RAC has more than 25%-RAC.展开更多
Two-order morphology of rock joints named as waviness and unevenness can be separated by morphology classification method,which plays a decisive role in the evolution of shear stress during the shear test.The joint mo...Two-order morphology of rock joints named as waviness and unevenness can be separated by morphology classification method,which plays a decisive role in the evolution of shear stress during the shear test.The joint morphology is obtained by using 3D printing and 3D laser scanning techniques and the joint model samples in two-order morphology are produced by cement mortar.Then,shear tests are performed under different normal loads.Results shows that the waviness is dominant in the total morphology during the shear test,and the shear contribution of unevenness mainly occurs in the climbing phase of shearing process.Comparing the failure modes of two-order morphology,waviness mainly embodies shear dilation characteristics and unevenness mainly shows shear wear characteristics.Based on this,a quantitative parameter is proposed to represent the ratio of the peak shear strength of the two-order morphology to that of total morphology.The functional relationship between the peak shear strength of total and two-order morphologies is determined,providing a theoretical method for further in-depth study on the shear strength of the interaction with two-order morphology of rock joints.展开更多
Froth flotation is an essential processing technique for upgrading low-grade ores.Flotation separation would not be efficient without chemical surfactants(collectors,depressants,frothers,etc.).Depressants play a criti...Froth flotation is an essential processing technique for upgrading low-grade ores.Flotation separation would not be efficient without chemical surfactants(collectors,depressants,frothers,etc.).Depressants play a critical role in the selective separation of minerals in that they deactivate unfavorable mineral surfaces and hinder them from floating into the flotation concentration zone.Pyrite is the most common and challenging sulfide gangue,and its conventional depressants could be highly harmful to nature and humans.Therefore,using available,affordable,eco-friendly polymers to assist or replace hazardous reagents is mandatory for a green transition.Polysaccharide-based(starch,dextrin,carboxymethyl cellulose,guar gum,etc.)polymers are one of the most used biodegradable depressant groups for pyrite depression.Despite the satisfactory flotation results obtained using these eco-friendly depressants,several gaps still need to be addressed,specifically in investigating surface interactions,adsorption mechanisms,and parameters affecting their depression performance.As a unique approach,this review comprehensively discussed previously conducted studies on pyrite depression with polysaccharide-based reagents.Additionally,practical suggestions have been provided for future assessments and developments of polysaccharide-based depressants,which pave the way to green flotation.This robust review also explored the depression efficiency and various adsorption aspects of naturally derived depressants on the pyrite surface to create a possible universal trend for each biodegradable depressant derivative.展开更多
利用MPM(material point method)计算方法,以爆炸焊接作为实例,对炸药滑移爆轰过程和金属飞板与基板之间的碰撞变形进行了数值模拟．并将无网格MPM法的数值计算结果与近似解析公式的计算结果进行了比较,二者基本吻合,有力地证明了无网格...利用MPM(material point method)计算方法,以爆炸焊接作为实例,对炸药滑移爆轰过程和金属飞板与基板之间的碰撞变形进行了数值模拟．并将无网格MPM法的数值计算结果与近似解析公式的计算结果进行了比较,二者基本吻合,有力地证明了无网格MPM法在求解爆炸冲击问题中的有效性和健壮性．展开更多
文摘During the modernization or rehabilitation activity,the demolished structural waste causes large soil pollution and unavailability of natural aggregate is the big concern for the construction industry.Therefore,this manuscript deals with the Composite Steel Circular Column(CSCC)with Recycled Aggregate concrete(RAC)as infill is partly used,with the replacement of 25%and 50%in M30 grade of Concrete.And internal reinforcement steel is fully replaced by rolled steel tubes(circular and square)with varied thickness,ISA-unequal angle.Around 14 specimens are cast and examined under axial load for analysis of the deflection characteristics,the load-bearing capacity along with its buckling behavior.The experimental values are estimated through LVDT(linear variable differential transducer)at 3-phase.The curve of load-deflection is drawn with the load pattern.From the date interpretation,it is found column made of 50%-RAC has more than 25%-RAC.
基金funded by National Natural Science Foundation of China(Grant Nos.42272333 and 42277147)。
文摘Two-order morphology of rock joints named as waviness and unevenness can be separated by morphology classification method,which plays a decisive role in the evolution of shear stress during the shear test.The joint morphology is obtained by using 3D printing and 3D laser scanning techniques and the joint model samples in two-order morphology are produced by cement mortar.Then,shear tests are performed under different normal loads.Results shows that the waviness is dominant in the total morphology during the shear test,and the shear contribution of unevenness mainly occurs in the climbing phase of shearing process.Comparing the failure modes of two-order morphology,waviness mainly embodies shear dilation characteristics and unevenness mainly shows shear wear characteristics.Based on this,a quantitative parameter is proposed to represent the ratio of the peak shear strength of the two-order morphology to that of total morphology.The functional relationship between the peak shear strength of total and two-order morphologies is determined,providing a theoretical method for further in-depth study on the shear strength of the interaction with two-order morphology of rock joints.
基金a project financially supported by CAMM3,the Center of Advanced Mining and Metallurgy,a center of excellence at the Lule?University of Technology。
文摘Froth flotation is an essential processing technique for upgrading low-grade ores.Flotation separation would not be efficient without chemical surfactants(collectors,depressants,frothers,etc.).Depressants play a critical role in the selective separation of minerals in that they deactivate unfavorable mineral surfaces and hinder them from floating into the flotation concentration zone.Pyrite is the most common and challenging sulfide gangue,and its conventional depressants could be highly harmful to nature and humans.Therefore,using available,affordable,eco-friendly polymers to assist or replace hazardous reagents is mandatory for a green transition.Polysaccharide-based(starch,dextrin,carboxymethyl cellulose,guar gum,etc.)polymers are one of the most used biodegradable depressant groups for pyrite depression.Despite the satisfactory flotation results obtained using these eco-friendly depressants,several gaps still need to be addressed,specifically in investigating surface interactions,adsorption mechanisms,and parameters affecting their depression performance.As a unique approach,this review comprehensively discussed previously conducted studies on pyrite depression with polysaccharide-based reagents.Additionally,practical suggestions have been provided for future assessments and developments of polysaccharide-based depressants,which pave the way to green flotation.This robust review also explored the depression efficiency and various adsorption aspects of naturally derived depressants on the pyrite surface to create a possible universal trend for each biodegradable depressant derivative.
文摘研究了CMAQ大气模型在64位Linux操作系统上不同CPU核心数目并行计算模拟耗时以及结果的差异情况。研究结果表明,并行计算能大幅缩短CMAQ模拟耗时,以16个CPU核心并行处理为性价比最佳值;此时连续模拟中国区域37天空气质量状况(分辨率36 km、167行×97列、垂直14层)平均耗时小于16 m in/d,而相同情况下单核模拟耗时大于2 h/d;多于16个核心并行处理时,随核心数量的增加模型性能提升的趋势减缓;操作系统和参与运算的核心数目对CMAQ模型模拟结果没有影响。
