This paper proposes an empirical formula to estimate the shear strength of hydraulic expansion rockbolts.The field experimental results were obtained from eleven pullout tests to evaluate the results computed by the p...This paper proposes an empirical formula to estimate the shear strength of hydraulic expansion rockbolts.The field experimental results were obtained from eleven pullout tests to evaluate the results computed by the proposed formula.It was found that shear resistance of hydraulic expansion rockbolts significantly depends on the uniaxial compressive strength and elastic modulus of rock,with high correlation coefficients of 0.7651 and0.8587,respectively.The developed formula enables estimation of the maximum pullout load in an analytical process without pullout tests in the field.Conversely,due to the poor interlocking at the initial pullout load,the measured displacements were higher than the estimated ones.To reduce the interlocking effects between bolt and rock,we recommend preloading of 29.4 kN.Preload allows reducing the distance between the measured and estimated displacement and making two load-displacement curves practically identical with marginal differences of 1.1 to 1.5 mm at the maximum pullout load.展开更多
Soybean(Glycine max L.)is a protein and oil crop grown worldwide.Its fitness may be reduced by deleterious mutations,whose identification and purging is desirable for crop breeding.In the published whole-genome re-seq...Soybean(Glycine max L.)is a protein and oil crop grown worldwide.Its fitness may be reduced by deleterious mutations,whose identification and purging is desirable for crop breeding.In the published whole-genome re-sequenced data of 2214 soybean accessions,including 221 wild soybean,1132 landrace cultivars and 861 improved soybean lines,we identified 115,275 deleterious single-nucleotide polymorphisms(SNPs).Numbers of deleterious alleles increased from wild soybeans to landraces and decreased from landraces to modern improved lines.Genes in selective-sweep regions showed fewer deleterious mutations than the remaining genes.Deleterious mutations explained 4.3%-48%more phenotypic variation than randomly selected SNPs for resistance to soybean cyst nematode race 2(SCN2),soybean cyst nematode race 3(SCN3)and soybean mosaic virus race 3(SMV3).These findings illustrate how mutation load has shifted during soybean domestication,expansion and improvement and provide candidate sites for breeding out deleterious mutations in soybean by genome editing and/or conventional breeding focused on the selection of progeny with fewer deleterious alleles.展开更多
基金supported by 2016 Hongik University Research Fund and the Convergence R&D program of MSIP/NST[Convergence Research-14-2-ETRI,Development of Internet of Things(IoT)-based Urban Underground Utility Monitoring and Management System]
文摘This paper proposes an empirical formula to estimate the shear strength of hydraulic expansion rockbolts.The field experimental results were obtained from eleven pullout tests to evaluate the results computed by the proposed formula.It was found that shear resistance of hydraulic expansion rockbolts significantly depends on the uniaxial compressive strength and elastic modulus of rock,with high correlation coefficients of 0.7651 and0.8587,respectively.The developed formula enables estimation of the maximum pullout load in an analytical process without pullout tests in the field.Conversely,due to the poor interlocking at the initial pullout load,the measured displacements were higher than the estimated ones.To reduce the interlocking effects between bolt and rock,we recommend preloading of 29.4 kN.Preload allows reducing the distance between the measured and estimated displacement and making two load-displacement curves practically identical with marginal differences of 1.1 to 1.5 mm at the maximum pullout load.
基金supported by the National Natural Science Foundation of China(32172002,32070242)Shenzhen Science and Technology Program(KQTD2016113010482651)+1 种基金Special Funds for Science Technology Innovation and Industrial Development of Shenzhen Dapeng New District(RC201901-05,PT201901-19)the USDA Agricultural Research Service Research Participation Program of the Oak Ridge Institute for Science and Education(ORISE)(DE-AC05-06OR23100).
文摘Soybean(Glycine max L.)is a protein and oil crop grown worldwide.Its fitness may be reduced by deleterious mutations,whose identification and purging is desirable for crop breeding.In the published whole-genome re-sequenced data of 2214 soybean accessions,including 221 wild soybean,1132 landrace cultivars and 861 improved soybean lines,we identified 115,275 deleterious single-nucleotide polymorphisms(SNPs).Numbers of deleterious alleles increased from wild soybeans to landraces and decreased from landraces to modern improved lines.Genes in selective-sweep regions showed fewer deleterious mutations than the remaining genes.Deleterious mutations explained 4.3%-48%more phenotypic variation than randomly selected SNPs for resistance to soybean cyst nematode race 2(SCN2),soybean cyst nematode race 3(SCN3)and soybean mosaic virus race 3(SMV3).These findings illustrate how mutation load has shifted during soybean domestication,expansion and improvement and provide candidate sites for breeding out deleterious mutations in soybean by genome editing and/or conventional breeding focused on the selection of progeny with fewer deleterious alleles.
