Arch bridges provide significant technical and economic benefits under suitable conditions.In particular,concrete-filled steel tubular(CFST)arch bridges and steel-reinforced concrete(SRC)arch bridges are two types of ...Arch bridges provide significant technical and economic benefits under suitable conditions.In particular,concrete-filled steel tubular(CFST)arch bridges and steel-reinforced concrete(SRC)arch bridges are two types of arch bridges that have gained great economic competitiveness and span growth potential due to advancements in construction technology,engineering materials,and construction equipment over the past 30 years.Under the leadership of the author,two record-breaking arch bridges—that is,the Pingnan Third Bridge(a CFST arch bridge),with a span of 560 m,and the Tian’e Longtan Bridge(an SRC arch bridge),with a span of 600 m—have been built in the past five years,embodying great technological breakthroughs in the construction of these two types of arch bridges.This paper takes these two arch bridges as examples to systematically summarize the latest technological innovations and practices in the construction of CFST arch bridges and SRC arch bridges in China.The technological innovations of CFST arch bridges include cable-stayed fastening-hanging cantilevered assembly methods,new in-tube concrete materials,in-tube concrete pouring techniques,a novel thrust abutment foundation for nonrocky terrain,and measures to reduce the quantity of temporary facilities.The technological innovations of SRC arch bridges involve arch skeleton stiffness selection,the development of encasing concrete materials,encasing concrete pouring,arch rib stress mitigation,and longitudinal reinforcement optimization.To conclude,future research focuses and development directions for these two types of arch bridges are proposed.展开更多
The Tibetan Partridge(Perdix hodgsoniae)is an endemic species distributed in high-altitude areas of 3600–5600 m on the Qinghai–Tibet Plateau.To explore how the species is adapted to the high elevation environment,we...The Tibetan Partridge(Perdix hodgsoniae)is an endemic species distributed in high-altitude areas of 3600–5600 m on the Qinghai–Tibet Plateau.To explore how the species is adapted to the high elevation environment,we as-sembled a draft genome based on both the Illumina and PacBio sequencing platforms with its population genetics and genomics analysis.In total,134.74 Gb short reads and 30.81 Gb long reads raw data were generated.The 1.05-Gb assembled genome had a contig N50 of 4.56 Mb,with 91.94%complete BUSCOs.The 17457 genes were annotated,and 11.35%of the genome was composed of repeat sequences.The phylogenetic tree showed that P.hodgsoniae was located at the basal position of the clade,including Golden Pheasant(Chrysolophus pictus),Common Pheasant(Phasianus colchicus),and Mikado Pheasant(Syrmaticus mikado).We found that 1014,2595,and 2732 of the 6641 one-to-one orthologous genes were under positive selection in P.hodgsoniae,detected using PAML,BUSTED,and aBSREL programs,respectively,of which 965 genes were common under positive selec-tion with 3 different programs.Several positively selected genes and immunity pathways relevant to high-altitude adaptation were detected.Gene family evolution showed that 99 gene families experienced significant expansion events,while 6 gene families were under contraction.The total number of olfactory receptor genes was relatively low in P.hodgsoniae.Genomic data provide an important resource for a further study on the evolutionary history of P.hodgsoniae,which provides a new insight into its high-altitude adaptation mechanisms.展开更多
基金financially supported by the Guangxi Key Research and Development Plan Program(AB22036007).
文摘Arch bridges provide significant technical and economic benefits under suitable conditions.In particular,concrete-filled steel tubular(CFST)arch bridges and steel-reinforced concrete(SRC)arch bridges are two types of arch bridges that have gained great economic competitiveness and span growth potential due to advancements in construction technology,engineering materials,and construction equipment over the past 30 years.Under the leadership of the author,two record-breaking arch bridges—that is,the Pingnan Third Bridge(a CFST arch bridge),with a span of 560 m,and the Tian’e Longtan Bridge(an SRC arch bridge),with a span of 600 m—have been built in the past five years,embodying great technological breakthroughs in the construction of these two types of arch bridges.This paper takes these two arch bridges as examples to systematically summarize the latest technological innovations and practices in the construction of CFST arch bridges and SRC arch bridges in China.The technological innovations of CFST arch bridges include cable-stayed fastening-hanging cantilevered assembly methods,new in-tube concrete materials,in-tube concrete pouring techniques,a novel thrust abutment foundation for nonrocky terrain,and measures to reduce the quantity of temporary facilities.The technological innovations of SRC arch bridges involve arch skeleton stiffness selection,the development of encasing concrete materials,encasing concrete pouring,arch rib stress mitigation,and longitudinal reinforcement optimization.To conclude,future research focuses and development directions for these two types of arch bridges are proposed.
基金The National Center for Biotechnology Information(NCBI)BioProject and BioSample accession numbers of Perdix hodgsoniae are PRJNA760267 and SAMN21212221,respectivelyThe raw reads have been deposited in the NCBI SRA database with the accession numbers SRR15900414(Illumina),SRR15900412,and SRR15900413(PacBio).
文摘The Tibetan Partridge(Perdix hodgsoniae)is an endemic species distributed in high-altitude areas of 3600–5600 m on the Qinghai–Tibet Plateau.To explore how the species is adapted to the high elevation environment,we as-sembled a draft genome based on both the Illumina and PacBio sequencing platforms with its population genetics and genomics analysis.In total,134.74 Gb short reads and 30.81 Gb long reads raw data were generated.The 1.05-Gb assembled genome had a contig N50 of 4.56 Mb,with 91.94%complete BUSCOs.The 17457 genes were annotated,and 11.35%of the genome was composed of repeat sequences.The phylogenetic tree showed that P.hodgsoniae was located at the basal position of the clade,including Golden Pheasant(Chrysolophus pictus),Common Pheasant(Phasianus colchicus),and Mikado Pheasant(Syrmaticus mikado).We found that 1014,2595,and 2732 of the 6641 one-to-one orthologous genes were under positive selection in P.hodgsoniae,detected using PAML,BUSTED,and aBSREL programs,respectively,of which 965 genes were common under positive selec-tion with 3 different programs.Several positively selected genes and immunity pathways relevant to high-altitude adaptation were detected.Gene family evolution showed that 99 gene families experienced significant expansion events,while 6 gene families were under contraction.The total number of olfactory receptor genes was relatively low in P.hodgsoniae.Genomic data provide an important resource for a further study on the evolutionary history of P.hodgsoniae,which provides a new insight into its high-altitude adaptation mechanisms.
