Close-distance coal seams are widely distributed over China,and the coal pillars left by the overlying coal seams afect the retracement channel of the underlying coal seam in the stopping stage.Based on the engineerin...Close-distance coal seams are widely distributed over China,and the coal pillars left by the overlying coal seams afect the retracement channel of the underlying coal seam in the stopping stage.Based on the engineering background of close-distance seam mining in a coal mine,the reasonable position of the underlying coal seam's stopping line and the support method of the large section roadway during stopping are investigated using feld measurements,similar simulation experiments,and numerical simulations.There are three types of location relationships between the stopping line of the underlying coal seam and the stopping line of the overlying coal seam:"externally staggered with the upper stopping line"(ESUL,stops mining under the overlying goaf),"overlapped with upper stopping line"(OUL),and"internally staggered with the upper stopping line"(ISUL,ISUL-SD for shorter internal staggered distances,ISUL-LD for longer ones).There are diferent stress arch structures in the overlying strata of the above three positions,and the stress arch evolution process exists in the process of ESUL→OUL→ISUL-SD→ISUL-LD:a front and rear double stress arch structure→the front arch gradually decreases→the front arch dies out,and the double arch synthesizes the single arch→the single-arch range expands→the nested double arch.The relationship between the stress arch structure and the position of the stopping line is evaluated as follows:(1)ESUL:the stress concentration in the roof plate of the retracement channel of the underlying coal seam is the highest,because the overburden block of the extensive collapse zone acts directly on the roof plate of the retracement channel,resulting in relative difculties in roof support.(2)OUL:although the retracement channel roof pressure is minimal,the overlying rock structure has the potential for rotation or slippage instability.(3)ISUL-SD:the pressure on the roof of the retracement channel is small and the overburden structure is stable,which is conducive to the safe retraction of the support and not limited by the width of the end-mining coal pillar.(4)ISUL-LD:it is basically the same as the condition of stopping under the non-goaf;however,it has a limitation on the width of the end-mining coal pillar.The location of the stopping line is selected as ISUL-SD,and the retraction process of the self-excavating retraction channel was adopted.A partition asymmetric support scheme which is proven by feld practice is proposed,through a comprehensive analysis of the pre-stress feld simulation of the support scheme,based on the diferent control requirements of the roof above the support and the roof of the retracement channel in the stopping area.This method realizes safe and smooth withdrawal of the support.展开更多
Long non-coding RNAs(lncRNAs)play key roles in colorectal carcinogenesis.Here,we aimed to identify the risk SNP-induced lncRNAs and to investigate their roles in colorectal carcinogenesis.First,we identified rs6695584...Long non-coding RNAs(lncRNAs)play key roles in colorectal carcinogenesis.Here,we aimed to identify the risk SNP-induced lncRNAs and to investigate their roles in colorectal carcinogenesis.First,we identified rs6695584 as the causative SNP in 1 q41 locus.The A>G mutation of rs6695584 created a protein-binding motif of BATF,altered the enhancer activity,and subsequently activated IncSLCCl expression.Further validation in two independent CRC cohorts confirmed the upregulation of IncSLCCl in CRC tissues,and revealed that increased IncSLCCl expression was associated with poor survival in CRC patients.Mechanistically,lncRNA-SLCCl interacted with AHR and transcriptionally activated HK2 expression,the crucial enzyme in glucose metabolism,thereby driving the glycolysis pathway and accelerating CRC tumor growth.The functional assays revealed that IncSLCCl induced glycolysis activation and tumor growth in CRC mediated by HK2.In addition,HK2 was upregulated in colorectal cancer tissues and positively correlated with IncSLCCl expression and patient survival.Taken together,our findings reveal a risk SNP-mediated oncogene lncRNA-SLCCl promotes CRC through activating the glycolysis pathway.展开更多
The first catalytic enantioselective C(sp)-C(sp^3) cross-coupling reaction between N-tosylhydrazones and trialkylsilylethynes in the presence of Cu(I) salts and chiral phosphoramidite ligands was developed. A se...The first catalytic enantioselective C(sp)-C(sp^3) cross-coupling reaction between N-tosylhydrazones and trialkylsilylethynes in the presence of Cu(I) salts and chiral phosphoramidite ligands was developed. A series of svnthetically interesting, functionalized alkynes were obtained with moderate to good enanttiselectivities (up to 83% ee). Cu(ll) carbene migratory insertion is proposed to be the enantio-determining step. KEYWORDS C(sp)--C(sp^3) cross-coupling, metal carbene, asymmetric catalysis, Cu(I) catalysts, N-tosylhydrazones展开更多
This paper proposes nonlinear Lagrangians based on modified Fischer-Burmeister NCP functions for solving nonlinear programming problems with inequality constraints. The convergence theorem shows that the sequence of p...This paper proposes nonlinear Lagrangians based on modified Fischer-Burmeister NCP functions for solving nonlinear programming problems with inequality constraints. The convergence theorem shows that the sequence of points generated by this nonlinear La- grange algorithm is locally convergent when the penalty parameter is less than a threshold under a set of suitable conditions on problem functions, and the error bound of solution, depending on the penalty parameter, is also established. It is shown that the condition number of the nonlinear Lagrangian Hessian at the optimal solution is proportional to the controlling penalty parameter. Moreover, the paper develops the dual algorithm associ- ated with the proposed nonlinear Lagrangians. Numerical results reported suggest that the dual algorithm based on proposed nonlinear Lagrangians is effective for solving some nonlinear optimization problems.展开更多
By utilizing the improvement function,we change the nonsmooth convex constrained optimization into an unconstrained optimization,and construct an infeasible quasi-Newton bundle method with proximal form.It should be n...By utilizing the improvement function,we change the nonsmooth convex constrained optimization into an unconstrained optimization,and construct an infeasible quasi-Newton bundle method with proximal form.It should be noted that the objective function being minimized in unconstrained optimization subproblem may vary along the iterations(it does not change if the null step is made,otherwise it is updated to a new function).It is necessary to make some adjustment in order to obtain the convergence result.We employ the main idea of infeasible bundle method of Sagastizabal and Solodov,and under the circumstances that each iteration point may be infeasible for primal problem,we prove that each cluster point of the sequence generated by the proposed algorithm is the optimal solution to the original problem.Furthermore,for BFGS quasi-Newton algorithm with strong convex objective function,we obtain the condition which guarantees the boundedness of quasi-Newton matrices and the R-linear convergence of the iteration points.展开更多
基金supported by the National Natural Science Foundation of China(52004286)the Fundamental Research Funds for the Central Universities(2022XJNY02)+3 种基金the National Natural Science Foundation of China(51974317,52074296)the China Postdoctoral Science Foundation(2020T130701,2019M650895)the Fundamental Research Funds for the Central Universities(2022YJSNY18,2022YJSNY09)all of which were gratefully acknowledged.
文摘Close-distance coal seams are widely distributed over China,and the coal pillars left by the overlying coal seams afect the retracement channel of the underlying coal seam in the stopping stage.Based on the engineering background of close-distance seam mining in a coal mine,the reasonable position of the underlying coal seam's stopping line and the support method of the large section roadway during stopping are investigated using feld measurements,similar simulation experiments,and numerical simulations.There are three types of location relationships between the stopping line of the underlying coal seam and the stopping line of the overlying coal seam:"externally staggered with the upper stopping line"(ESUL,stops mining under the overlying goaf),"overlapped with upper stopping line"(OUL),and"internally staggered with the upper stopping line"(ISUL,ISUL-SD for shorter internal staggered distances,ISUL-LD for longer ones).There are diferent stress arch structures in the overlying strata of the above three positions,and the stress arch evolution process exists in the process of ESUL→OUL→ISUL-SD→ISUL-LD:a front and rear double stress arch structure→the front arch gradually decreases→the front arch dies out,and the double arch synthesizes the single arch→the single-arch range expands→the nested double arch.The relationship between the stress arch structure and the position of the stopping line is evaluated as follows:(1)ESUL:the stress concentration in the roof plate of the retracement channel of the underlying coal seam is the highest,because the overburden block of the extensive collapse zone acts directly on the roof plate of the retracement channel,resulting in relative difculties in roof support.(2)OUL:although the retracement channel roof pressure is minimal,the overlying rock structure has the potential for rotation or slippage instability.(3)ISUL-SD:the pressure on the roof of the retracement channel is small and the overburden structure is stable,which is conducive to the safe retraction of the support and not limited by the width of the end-mining coal pillar.(4)ISUL-LD:it is basically the same as the condition of stopping under the non-goaf;however,it has a limitation on the width of the end-mining coal pillar.The location of the stopping line is selected as ISUL-SD,and the retraction process of the self-excavating retraction channel was adopted.A partition asymmetric support scheme which is proven by feld practice is proposed,through a comprehensive analysis of the pre-stress feld simulation of the support scheme,based on the diferent control requirements of the roof above the support and the roof of the retracement channel in the stopping area.This method realizes safe and smooth withdrawal of the support.
基金supported in part by grants from the State Key R&D Program(2020YFA0509200)the National Natural Science Foundation of China(81421001,81530072,81830081,81871901,81874159,81902368,31970718,81770165)+4 种基金Shanghai Municipal Health Commission,Collaborative Innovation Cluster Project(2019CXJQ02)"Shu Guang"project supported by Shanghai Municipal Education Commission and Shanghai Education Developm ent Foundation(17SG18)the Program for Professor of Special Appointm ent(Eastern Scholar No.201268 and 2015 Youth Eastern Scholar No.QD2015003)at Shanghai Institutions of Higher LearningShanghai Municipal Education Commission—Gaofeng Clinical Medicine Grant Support(No.20152512,20161309)Innovative research team of high-level local universities in Shanghai.
文摘Long non-coding RNAs(lncRNAs)play key roles in colorectal carcinogenesis.Here,we aimed to identify the risk SNP-induced lncRNAs and to investigate their roles in colorectal carcinogenesis.First,we identified rs6695584 as the causative SNP in 1 q41 locus.The A>G mutation of rs6695584 created a protein-binding motif of BATF,altered the enhancer activity,and subsequently activated IncSLCCl expression.Further validation in two independent CRC cohorts confirmed the upregulation of IncSLCCl in CRC tissues,and revealed that increased IncSLCCl expression was associated with poor survival in CRC patients.Mechanistically,lncRNA-SLCCl interacted with AHR and transcriptionally activated HK2 expression,the crucial enzyme in glucose metabolism,thereby driving the glycolysis pathway and accelerating CRC tumor growth.The functional assays revealed that IncSLCCl induced glycolysis activation and tumor growth in CRC mediated by HK2.In addition,HK2 was upregulated in colorectal cancer tissues and positively correlated with IncSLCCl expression and patient survival.Taken together,our findings reveal a risk SNP-mediated oncogene lncRNA-SLCCl promotes CRC through activating the glycolysis pathway.
基金Acknowledgement The project is supported by the National Basic Research Program of China (973 Program, No. 2015CB856600), the National Natural Science Foundation of China (Grant 21472004, 21332002) and the China Postdoctoral Science Foundation Funded Project (2015M5B0911).
文摘The first catalytic enantioselective C(sp)-C(sp^3) cross-coupling reaction between N-tosylhydrazones and trialkylsilylethynes in the presence of Cu(I) salts and chiral phosphoramidite ligands was developed. A series of svnthetically interesting, functionalized alkynes were obtained with moderate to good enanttiselectivities (up to 83% ee). Cu(ll) carbene migratory insertion is proposed to be the enantio-determining step. KEYWORDS C(sp)--C(sp^3) cross-coupling, metal carbene, asymmetric catalysis, Cu(I) catalysts, N-tosylhydrazones
文摘This paper proposes nonlinear Lagrangians based on modified Fischer-Burmeister NCP functions for solving nonlinear programming problems with inequality constraints. The convergence theorem shows that the sequence of points generated by this nonlinear La- grange algorithm is locally convergent when the penalty parameter is less than a threshold under a set of suitable conditions on problem functions, and the error bound of solution, depending on the penalty parameter, is also established. It is shown that the condition number of the nonlinear Lagrangian Hessian at the optimal solution is proportional to the controlling penalty parameter. Moreover, the paper develops the dual algorithm associ- ated with the proposed nonlinear Lagrangians. Numerical results reported suggest that the dual algorithm based on proposed nonlinear Lagrangians is effective for solving some nonlinear optimization problems.
文摘By utilizing the improvement function,we change the nonsmooth convex constrained optimization into an unconstrained optimization,and construct an infeasible quasi-Newton bundle method with proximal form.It should be noted that the objective function being minimized in unconstrained optimization subproblem may vary along the iterations(it does not change if the null step is made,otherwise it is updated to a new function).It is necessary to make some adjustment in order to obtain the convergence result.We employ the main idea of infeasible bundle method of Sagastizabal and Solodov,and under the circumstances that each iteration point may be infeasible for primal problem,we prove that each cluster point of the sequence generated by the proposed algorithm is the optimal solution to the original problem.Furthermore,for BFGS quasi-Newton algorithm with strong convex objective function,we obtain the condition which guarantees the boundedness of quasi-Newton matrices and the R-linear convergence of the iteration points.