The intersection is a widely used traffic line structure from the shallow tunnel to the deep roadway,and determining the subsidence hidden danger area of the roof is the key to its stability control.However,applying t...The intersection is a widely used traffic line structure from the shallow tunnel to the deep roadway,and determining the subsidence hidden danger area of the roof is the key to its stability control.However,applying traditional maximum equivalent span beam(MESB)theory to determine deformation range,peak point,and angle influence poses a challenge.Considering the overall structure of the intersection roof,the maximum equivalent triangular plate(METP)theory is proposed,and its geometric parameter calculation formula and deflection calculation formula are obtained.The application of the two theories in 18 models with different intersection angles,roadway types,and surrounding rock lithology is verified by numerical analysis.The results show that:1)The METP structure of the intersection roof established by the simulation results of each model successfully determined the location of the roof’s high displacement zone;2)The area comparison method of the METP theory can be reasonably explained:①The roof subsidence of the intersection decreases with the increase of the intersection angle;②The roof subsidence at the intersection of different roadway types has a rectangular type>arch type>circular type;③The roof subsidence of the intersection with weak surrounding rock is significantly larger than that of the intersection with hard surrounding rock.According to the application results of the two theories,the four advantages of the METP theory are compared and clarified in the basic assumptions,mechanical models,main viewpoints,and mechanism analysis.The large deformation inducement of the intersection roof is then explored.The J 2 peak area of the roof drives the large deformation of the area,the peak point of which is consistent with the center of gravity position of the METP.Furthermore,the change in the range of this peak is consistent with the change law of the METP’s area.Hence,this theory clarifies the large deformation area of the intersection roof,which provides a clear guiding basis for its initial support design,mid-term monitoring,and late local reinforcement.展开更多
Surface tension of calcium aluminate refining slag was measured by the Slide method at 1823 K.Based on different levels of the MgO content and the mass ratio of CaO to Al_2O_3,the effects of MgO content and the mass r...Surface tension of calcium aluminate refining slag was measured by the Slide method at 1823 K.Based on different levels of the MgO content and the mass ratio of CaO to Al_2O_3,the effects of MgO content and the mass ratio of CaO to Al_2O_3 on surface tension were investigated.The results indicate that surface tension decreased with increasing MgO content(from 0 to 4.86%),followed by an increase with further increasing MgO content up to 11.33%.The trend that surface tension changed with the mass ratio of CaO to Al_2O_3 was the same as the trend that surface tension changed with the MgO content.The surface tension was varied from 0.617 N/m to 0.710 N/m,for the mass ratio of CaO to Al_2O_3 varying between 0.60 and 1.28.An attempt was made to estimate surface tension of CaO-Al_2O_3-MgO slag and its sub-system,and the application showed that the model worked well.展开更多
A novel quantitative structure-property relationship （QSPR） model for estimating the solution surface tension of 92 organic compounds at 20℃ was developed based on newly introduced atom-type topological indices. Th...A novel quantitative structure-property relationship （QSPR） model for estimating the solution surface tension of 92 organic compounds at 20℃ was developed based on newly introduced atom-type topological indices. The data set contained non-polar and polar liquids, and saturated and unsaturated compounds. The regression analysis shows that excellent result is obtained with multiple linear regression. The predictive power of the proposed model was discussed using the leave-one-out （LOO） cross-validated （CV） method. The correlation coefficient （R） and the leave-one-out cross-validation correlation coefficient （Rcv） of multiple linear regression model are 0.991 4 and 0.991 3, respectively. The new model gives the average absolute relative deviation of 1.81% for 92 substances. The result demonstrates that novel topological indices based on the equilibrium electro-negativity of atom and the relative bond length are useful model parameters for QSPR analysis of compounds.展开更多
Surface tensions of slag addition Mg O and Si O2 based on conventional 70%CaF 2-30%Al2O3 and 60%Ca F2-20%Ca O-20%Al2O3(mass fraction) at 1300 °C, 1400 °C and 1500 °C were investigated. Influence mechani...Surface tensions of slag addition Mg O and Si O2 based on conventional 70%CaF 2-30%Al2O3 and 60%Ca F2-20%Ca O-20%Al2O3(mass fraction) at 1300 °C, 1400 °C and 1500 °C were investigated. Influence mechanism of Mg O and Si O2 on slag surface tension was also analyzed. Results indicate that surface tension decreases with the increase of Mg O content in the case of the Mg O content(mass fraction) less than 8%, however, when Mg O content(mass fraction) is from 8% to 30%, surface tension increases with the increase of Mg O content. When Si O2 content(mass fraction) is from 2% to 8%, surface tension decreases with the increase of Si O2 content. Additionally, the relationship between surface tension and optical basicity is a monotonically increasing linear function. Research findings can provide important reference for slag design and the study of slag-metal interfacial tension.展开更多
基金Project(52204164)supported by the National Natural Science Foundation of ChinaProject(2021QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,China。
文摘The intersection is a widely used traffic line structure from the shallow tunnel to the deep roadway,and determining the subsidence hidden danger area of the roof is the key to its stability control.However,applying traditional maximum equivalent span beam(MESB)theory to determine deformation range,peak point,and angle influence poses a challenge.Considering the overall structure of the intersection roof,the maximum equivalent triangular plate(METP)theory is proposed,and its geometric parameter calculation formula and deflection calculation formula are obtained.The application of the two theories in 18 models with different intersection angles,roadway types,and surrounding rock lithology is verified by numerical analysis.The results show that:1)The METP structure of the intersection roof established by the simulation results of each model successfully determined the location of the roof’s high displacement zone;2)The area comparison method of the METP theory can be reasonably explained:①The roof subsidence of the intersection decreases with the increase of the intersection angle;②The roof subsidence at the intersection of different roadway types has a rectangular type>arch type>circular type;③The roof subsidence of the intersection with weak surrounding rock is significantly larger than that of the intersection with hard surrounding rock.According to the application results of the two theories,the four advantages of the METP theory are compared and clarified in the basic assumptions,mechanical models,main viewpoints,and mechanism analysis.The large deformation inducement of the intersection roof is then explored.The J 2 peak area of the roof drives the large deformation of the area,the peak point of which is consistent with the center of gravity position of the METP.Furthermore,the change in the range of this peak is consistent with the change law of the METP’s area.Hence,this theory clarifies the large deformation area of the intersection roof,which provides a clear guiding basis for its initial support design,mid-term monitoring,and late local reinforcement.
基金Project(51204115)supported by the National Natural Science Foundation of ChinaProject(BK20130308)supported by the Basic Research Program of Jiangsu Province,ChinaProject(2014M561710)supported by China Postdoctoral Science Foundation
文摘Surface tension of calcium aluminate refining slag was measured by the Slide method at 1823 K.Based on different levels of the MgO content and the mass ratio of CaO to Al_2O_3,the effects of MgO content and the mass ratio of CaO to Al_2O_3 on surface tension were investigated.The results indicate that surface tension decreased with increasing MgO content(from 0 to 4.86%),followed by an increase with further increasing MgO content up to 11.33%.The trend that surface tension changed with the mass ratio of CaO to Al_2O_3 was the same as the trend that surface tension changed with the MgO content.The surface tension was varied from 0.617 N/m to 0.710 N/m,for the mass ratio of CaO to Al_2O_3 varying between 0.60 and 1.28.An attempt was made to estimate surface tension of CaO-Al_2O_3-MgO slag and its sub-system,and the application showed that the model worked well.
基金Projects(20775010,21075011) supported by the National Natural Science Foundation of ChinaProject(2008AA05Z405) supported by the National High Technology Research and Development Program of China+2 种基金Project(09JJ3016) supported by Hunan Provincial Natural Science Foundation,ChinaProject(09C066) supported by Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(2010CL01) supported by the Foundation of Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,China
文摘A novel quantitative structure-property relationship （QSPR） model for estimating the solution surface tension of 92 organic compounds at 20℃ was developed based on newly introduced atom-type topological indices. The data set contained non-polar and polar liquids, and saturated and unsaturated compounds. The regression analysis shows that excellent result is obtained with multiple linear regression. The predictive power of the proposed model was discussed using the leave-one-out （LOO） cross-validated （CV） method. The correlation coefficient （R） and the leave-one-out cross-validation correlation coefficient （Rcv） of multiple linear regression model are 0.991 4 and 0.991 3, respectively. The new model gives the average absolute relative deviation of 1.81% for 92 substances. The result demonstrates that novel topological indices based on the equilibrium electro-negativity of atom and the relative bond length are useful model parameters for QSPR analysis of compounds.
基金Project(51274266)supported by the National Natural Science Foundation of ChinaProject(N120502002)supported by the Fundamental Research Funds for Central Universities of ChinaProject(LR2013009)supported by the Program for Liaoning Excellent Talents in University,China
文摘Surface tensions of slag addition Mg O and Si O2 based on conventional 70%CaF 2-30%Al2O3 and 60%Ca F2-20%Ca O-20%Al2O3(mass fraction) at 1300 °C, 1400 °C and 1500 °C were investigated. Influence mechanism of Mg O and Si O2 on slag surface tension was also analyzed. Results indicate that surface tension decreases with the increase of Mg O content in the case of the Mg O content(mass fraction) less than 8%, however, when Mg O content(mass fraction) is from 8% to 30%, surface tension increases with the increase of Mg O content. When Si O2 content(mass fraction) is from 2% to 8%, surface tension decreases with the increase of Si O2 content. Additionally, the relationship between surface tension and optical basicity is a monotonically increasing linear function. Research findings can provide important reference for slag design and the study of slag-metal interfacial tension.
