Anchoring mechanism and failure characteristics of composite soft rock with weak interface usually exhibit remarkable difference from those in single rock mass.In order to fully understand the reinforcement mechanism ...Anchoring mechanism and failure characteristics of composite soft rock with weak interface usually exhibit remarkable difference from those in single rock mass.In order to fully understand the reinforcement mechanism of composite soft roof in western mining area of China,a mechanical model of composite soft rock with weak interface and rock bolt which considering the transverse shear sliding between different rock layers was established firstly.The anchoring effect was quantified by a factor defined as anchoring effect coefficient and its evolution equation was further deduced based on the deformation relationship and homogenized distribution assumption of stress acting on composite structure.Meanwhile,the numerical simulation model of composite soft rock with shear joint was prompted by finite element method.Then detailed analysis were carried out for the deformation features,stress distribution and failure behavior of rock mass and rock bolt near the joint under transverse load.The theoretical result indicates that the anchoring effect of rock-bolt through weak joint changes with the working status of rock mass and closely relates with the physical and geometric parameters of rock mass and rock bolt.From the numerical results,the bending deformation of rock bolt accurately characterized by Doseresp model is mainly concentrated between two plastic hinges near the shear joint.The maximum tensile and compression stresses distribute in the plastic hinge.However,the maximum shear stress appears at the positions of joint surface.The failure zones of composite rock are produced firstly at the joint surface due to the reaction of rock bolt.The above results laid a theoretical and computational foundation for further study of anchorage failure in composite soft rock.展开更多
To establish a rapid, accurate and economical real-time PCR assay system based on TaqMan probe technology for the detection of genetic variations of single nucleotide polymorphisms （SNPs） in myestatin （MSTN） gene,...To establish a rapid, accurate and economical real-time PCR assay system based on TaqMan probe technology for the detection of genetic variations of single nucleotide polymorphisms （SNPs） in myestatin （MSTN） gene, a pair of TaqMan probes were designed on the polymorphism loci of MSTN gene and used in PCR reaction system for SNP genotyping. Meanwhile, an association study was performed between MSTN genotypes and growth traits of Tan sheep, including birth weight, weaning weight, 3-month weight, and 6-month weight. The results showed that rs417816017 locus of MSTN gene in Tan sheep had two genotypes ： YY and XY. The individuals with genotype XY had a growth advantage over the ones with genotype YY. The results indicate that TaqMan probe-based real-time PCR assay can be used to detect the genotype of MSTN gene, which will provide candidate genes for breeding of Tan sheep.展开更多
基金Projects(51774196,41472280,51578327)supported by the National Natural Science Foundation of ChinaProject(2016M592221)supported by the China Postdoctoral Science FoundationProject(BJRC20160501)supported by the SDUST Young Teachers Teaching Talent Training Plan,China
文摘Anchoring mechanism and failure characteristics of composite soft rock with weak interface usually exhibit remarkable difference from those in single rock mass.In order to fully understand the reinforcement mechanism of composite soft roof in western mining area of China,a mechanical model of composite soft rock with weak interface and rock bolt which considering the transverse shear sliding between different rock layers was established firstly.The anchoring effect was quantified by a factor defined as anchoring effect coefficient and its evolution equation was further deduced based on the deformation relationship and homogenized distribution assumption of stress acting on composite structure.Meanwhile,the numerical simulation model of composite soft rock with shear joint was prompted by finite element method.Then detailed analysis were carried out for the deformation features,stress distribution and failure behavior of rock mass and rock bolt near the joint under transverse load.The theoretical result indicates that the anchoring effect of rock-bolt through weak joint changes with the working status of rock mass and closely relates with the physical and geometric parameters of rock mass and rock bolt.From the numerical results,the bending deformation of rock bolt accurately characterized by Doseresp model is mainly concentrated between two plastic hinges near the shear joint.The maximum tensile and compression stresses distribute in the plastic hinge.However,the maximum shear stress appears at the positions of joint surface.The failure zones of composite rock are produced firstly at the joint surface due to the reaction of rock bolt.The above results laid a theoretical and computational foundation for further study of anchorage failure in composite soft rock.
基金Supported by Special Fund for Science and Technology Development of Ningxia Hui Autonomous Region(2012ZDN1001)Domestic Animal Germplasm Resources Sharing Platform Project(2005DKA21101)
文摘To establish a rapid, accurate and economical real-time PCR assay system based on TaqMan probe technology for the detection of genetic variations of single nucleotide polymorphisms （SNPs） in myestatin （MSTN） gene, a pair of TaqMan probes were designed on the polymorphism loci of MSTN gene and used in PCR reaction system for SNP genotyping. Meanwhile, an association study was performed between MSTN genotypes and growth traits of Tan sheep, including birth weight, weaning weight, 3-month weight, and 6-month weight. The results showed that rs417816017 locus of MSTN gene in Tan sheep had two genotypes ： YY and XY. The individuals with genotype XY had a growth advantage over the ones with genotype YY. The results indicate that TaqMan probe-based real-time PCR assay can be used to detect the genotype of MSTN gene, which will provide candidate genes for breeding of Tan sheep.
