In the process of using the original key stratum theory to predict the height of a water-flowing fractured zone(WFZ),the influence of rock strata outside the calculation range on the rock strata within the calculation...In the process of using the original key stratum theory to predict the height of a water-flowing fractured zone(WFZ),the influence of rock strata outside the calculation range on the rock strata within the calculation range as well as the fact that the shape of the overburden deformation area will change with the excavation length are ignored.In this paper,an improved key stratum theory(IKS theory)was proposed by fixing these two shortcomings.Then,a WFZ height prediction method based on IKS theory was established and applied.First,the range of overburden involved in the analysis was determined according to the tensile stress distribution range above the goaf.Second,the key stratum in the overburden involved in the analysis was identified through IKS theory.Finally,the tendency of the WFZ to develop upward was determined by judging whether or not the identified key stratum will break.The proposed method was applied and verified in a mining case study,and the reasons for the differences in the development patterns between the WFZs in coalfields in Northwest and East China were also fully explained by this method.展开更多
Based on Least Square Method, this paper presents variational principle for handling various water gravity wave theories and the unified water gravity wave theory was given. By using this variational principle of unif...Based on Least Square Method, this paper presents variational principle for handling various water gravity wave theories and the unified water gravity wave theory was given. By using this variational principle of unified water wave theory, two kinds of improved linear waves were derived. The first one uses the same boundary conditions which were applied to derive 5-order Stokes wave. The second one uses the accurate boundary conditions (Eqs. 11 and 12). The two improved linear waves were compared with the existing linear wave.展开更多
Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of ...Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, R1, R2, R'3, R'2, and R'1 lines, U band, ground-state zero-field-splitting (GSZFS), and ground-state g factors of ruby and/or GSGG: Cr3+ as well as thermal shifts of GSZFS, R1 line and R2 line of ruby have been calculated.The results are in very good agreement with the experimental data. Moreover, it is found that the value of cubic-field parameter given by traditional ligand-field theory is inappropriately large. For thermal shifts of GSZFS, R1 line and R2 line of ruby, several conclusions have also been obtained.展开更多
Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved...Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, the R-line, t^3 2^2 T1 lines, t^2 2(^3 T1)e^4 T2, and t^2 2(^3T1)e^4T1 bands, ground-state g factor, four strain-induced level- splittings, and R-line thermal shift of MgO:Cr^3+ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO:Cr^3+, the contributions due to electron-phonon interaction (EPI) come from the first-order term. In thermal shift of R-line of MgO:Cr^3+, the temperature-dependent contribution due to EPI is dominant.展开更多
With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wave...With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wavefunc-tions within d^3 electronic configuration,the R-line thermal broadenings(TB)of both MgO:Cr^(3+)and MgO:V^(2+)havemicroscopic-theoretically been calculated.The results are in very good agreement with the experimental data.It is foundthat the R-line TB of MgO:Cr^(3+)or MgO:V^(2+)comes from the first-order term of EPI.The elastic Raman scattering ofacoustic phonons plays a dominant role in R-line TB of MgO:Cr^(3+)or MgO:V^(2+).展开更多
Grey theory is a multidisciplinary and generic theory to cope with systems of poor or deficient information. We proposed in this paper an improved grey method (GM) to overcome the disadvantages of the general GM(1,1)....Grey theory is a multidisciplinary and generic theory to cope with systems of poor or deficient information. We proposed in this paper an improved grey method (GM) to overcome the disadvantages of the general GM(1,1). In the improved GM(1,1), a new background value formula is deduced and Markov-chain sign estimation is imbedded into the residual modification model. We tested the efficiency and accuracy of our model by applying it to the power demand forecasting in Taiwan. Experimental results demonstrate the new method has obviously a higher prediction accuracy than the general model.展开更多
By means of an improved ligand-field theory, the "pure electronic" PS and the PS due to EPI of R line of MgO: V^2+ have been calculated, respectively. The calculated results are in very good agreement with the exp...By means of an improved ligand-field theory, the "pure electronic" PS and the PS due to EPI of R line of MgO: V^2+ have been calculated, respectively. The calculated results are in very good agreement with the experimental data. The behaviors of the pure electronic PS of R line of MgO:V^2+ and the PS of its R line due to EPI are different. It is the combined effect of them that gives rise to the total PS of R line, which has satisfactorily explained the experimental results. The mixing-degree of |t2^2(^3T1)e^4T2〉 and |t2^3 ^2E〉 in the wavefunetion of R level and its variation with pressure have been calculated and analyzed. The comparison between the feature of R-line PS of MgO:V^2+ and that of MgO:Cr^3+ has been made.展开更多
为解决基坑坍塌风险评价等级问题,优化模糊综合评价模型以提高基坑风险等级评估的准确性,从而采取有效治理措施控制基坑风险。首先,采用层次模型建立基坑坍塌风险评价指标体系,定性指标采用量化等级进行定量转化,然后引入模糊集理论建...为解决基坑坍塌风险评价等级问题,优化模糊综合评价模型以提高基坑风险等级评估的准确性,从而采取有效治理措施控制基坑风险。首先,采用层次模型建立基坑坍塌风险评价指标体系,定性指标采用量化等级进行定量转化,然后引入模糊集理论建立评价指标模糊关系,针对传统层次分析法(analytic hierarchy process,AHP)不能处理模糊性及不完整性信息的缺点,采用D数理论改进层次法(D-AHP)确定一级指标主观权重,提高了在赋权过程中专家对指标的偏好性;为提高评价体系中风险指标权重的精确性,综合熵权法(entropy weight method,EWM)和指标相关性权重确定法(criteria importance through intercriteria correlation,CRITIC)的赋权优点,利用改进博弈论对熵权法和CRITIC法求出的二级指标权重进行组合赋权,得到二级指标客观权重,线性耦合主客观权重得到最终权重,从而建立基坑坍塌风险评价模型,根据最大隶属度原则确定基坑风险等级;同时,建立基于施工监测数据结合改进博弈论组合赋权的逼近理想解排序法(technique for order preference by similarity to an idea solution,TOPSIS)评价模型进行对比验证。结合昆明5号线某地铁基坑为例进行风险评价,结果表明:模型评价结果与实际工程情况相吻合,验证了改进博弈论组合赋权结合模糊集评价模型的正确性和可靠性,同时验证了组合赋权的合理性,为基坑风险评估提供新的参考方法。展开更多
基金supported by the Key Projects of Natural Science Foundation of China(No.41931284)the Scientific Research Start-Up Fund for High-Level Introduced Talents of Anhui University of Science and Technology(No.2022yjrc21).
文摘In the process of using the original key stratum theory to predict the height of a water-flowing fractured zone(WFZ),the influence of rock strata outside the calculation range on the rock strata within the calculation range as well as the fact that the shape of the overburden deformation area will change with the excavation length are ignored.In this paper,an improved key stratum theory(IKS theory)was proposed by fixing these two shortcomings.Then,a WFZ height prediction method based on IKS theory was established and applied.First,the range of overburden involved in the analysis was determined according to the tensile stress distribution range above the goaf.Second,the key stratum in the overburden involved in the analysis was identified through IKS theory.Finally,the tendency of the WFZ to develop upward was determined by judging whether or not the identified key stratum will break.The proposed method was applied and verified in a mining case study,and the reasons for the differences in the development patterns between the WFZs in coalfields in Northwest and East China were also fully explained by this method.
文摘Based on Least Square Method, this paper presents variational principle for handling various water gravity wave theories and the unified water gravity wave theory was given. By using this variational principle of unified water wave theory, two kinds of improved linear waves were derived. The first one uses the same boundary conditions which were applied to derive 5-order Stokes wave. The second one uses the accurate boundary conditions (Eqs. 11 and 12). The two improved linear waves were compared with the existing linear wave.
文摘Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, R1, R2, R'3, R'2, and R'1 lines, U band, ground-state zero-field-splitting (GSZFS), and ground-state g factors of ruby and/or GSGG: Cr3+ as well as thermal shifts of GSZFS, R1 line and R2 line of ruby have been calculated.The results are in very good agreement with the experimental data. Moreover, it is found that the value of cubic-field parameter given by traditional ligand-field theory is inappropriately large. For thermal shifts of GSZFS, R1 line and R2 line of ruby, several conclusions have also been obtained.
文摘Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, the R-line, t^3 2^2 T1 lines, t^2 2(^3 T1)e^4 T2, and t^2 2(^3T1)e^4T1 bands, ground-state g factor, four strain-induced level- splittings, and R-line thermal shift of MgO:Cr^3+ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO:Cr^3+, the contributions due to electron-phonon interaction (EPI) come from the first-order term. In thermal shift of R-line of MgO:Cr^3+, the temperature-dependent contribution due to EPI is dominant.
基金supported partially by National Natural Science Foundation of China under Grant No.40841012
文摘With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wavefunc-tions within d^3 electronic configuration,the R-line thermal broadenings(TB)of both MgO:Cr^(3+)and MgO:V^(2+)havemicroscopic-theoretically been calculated.The results are in very good agreement with the experimental data.It is foundthat the R-line TB of MgO:Cr^(3+)or MgO:V^(2+)comes from the first-order term of EPI.The elastic Raman scattering ofacoustic phonons plays a dominant role in R-line TB of MgO:Cr^(3+)or MgO:V^(2+).
文摘Grey theory is a multidisciplinary and generic theory to cope with systems of poor or deficient information. We proposed in this paper an improved grey method (GM) to overcome the disadvantages of the general GM(1,1). In the improved GM(1,1), a new background value formula is deduced and Markov-chain sign estimation is imbedded into the residual modification model. We tested the efficiency and accuracy of our model by applying it to the power demand forecasting in Taiwan. Experimental results demonstrate the new method has obviously a higher prediction accuracy than the general model.
文摘By means of an improved ligand-field theory, the "pure electronic" PS and the PS due to EPI of R line of MgO: V^2+ have been calculated, respectively. The calculated results are in very good agreement with the experimental data. The behaviors of the pure electronic PS of R line of MgO:V^2+ and the PS of its R line due to EPI are different. It is the combined effect of them that gives rise to the total PS of R line, which has satisfactorily explained the experimental results. The mixing-degree of |t2^2(^3T1)e^4T2〉 and |t2^3 ^2E〉 in the wavefunetion of R level and its variation with pressure have been calculated and analyzed. The comparison between the feature of R-line PS of MgO:V^2+ and that of MgO:Cr^3+ has been made.
文摘为解决基坑坍塌风险评价等级问题,优化模糊综合评价模型以提高基坑风险等级评估的准确性,从而采取有效治理措施控制基坑风险。首先,采用层次模型建立基坑坍塌风险评价指标体系,定性指标采用量化等级进行定量转化,然后引入模糊集理论建立评价指标模糊关系,针对传统层次分析法(analytic hierarchy process,AHP)不能处理模糊性及不完整性信息的缺点,采用D数理论改进层次法(D-AHP)确定一级指标主观权重,提高了在赋权过程中专家对指标的偏好性;为提高评价体系中风险指标权重的精确性,综合熵权法(entropy weight method,EWM)和指标相关性权重确定法(criteria importance through intercriteria correlation,CRITIC)的赋权优点,利用改进博弈论对熵权法和CRITIC法求出的二级指标权重进行组合赋权,得到二级指标客观权重,线性耦合主客观权重得到最终权重,从而建立基坑坍塌风险评价模型,根据最大隶属度原则确定基坑风险等级;同时,建立基于施工监测数据结合改进博弈论组合赋权的逼近理想解排序法(technique for order preference by similarity to an idea solution,TOPSIS)评价模型进行对比验证。结合昆明5号线某地铁基坑为例进行风险评价,结果表明:模型评价结果与实际工程情况相吻合,验证了改进博弈论组合赋权结合模糊集评价模型的正确性和可靠性,同时验证了组合赋权的合理性,为基坑风险评估提供新的参考方法。