In this paper,a numerical simulation model of the flow field in a gearbox with an oil volume adjusting device is established for the first time to study its influence on the lubrication characteristics of a high-speed...In this paper,a numerical simulation model of the flow field in a gearbox with an oil volume adjusting device is established for the first time to study its influence on the lubrication characteristics of a high-speed electric multiple unit(EMU)gearbox.The moving particle semi-implicit(MPS)method is used to numerically simulate the internal flow field of the gearbox of the high-speed EMU under working conditions.The effects of the velocity of the high-speed EMU,the immersion depth,and the oil sump temperature on the power loss of the gears and the lubricant quantity of each bearing are studied and provide an effective tool for the quantitative evaluation of the lubrication characteristics of the gearbox.The lubrication characteristics of the gearbox under different working conditions are studied when the oil volume adjusting device is closed and opened.The results show that the oil volume adjusting device mainly changes the amount of lubricant stirred by the output gear by changing the flow rate of lubricant from the cavity pinion(Cavity P)to the cavity gear(Cavity G),and thus affects the power loss of gears and the lubricant quantity of each bearing.展开更多
Background:Common and rare variants of guanosine triphosphate cyclohydrolase 1(GCH1)gene may play important roles in Parkinson's disease(PD).However,there is a lack of comprehensive analysis of GCH1 genotypes,espe...Background:Common and rare variants of guanosine triphosphate cyclohydrolase 1(GCH1)gene may play important roles in Parkinson's disease(PD).However,there is a lack of comprehensive analysis of GCH1 genotypes,especially in non-coding regions.The aim of this study was to explore the genetic characteristics of GCH1,including rare and common variants in coding and non-coding regions,in a large population of PD patients in Chinese mainland,as well as the phenotypic characteristics of GCH1 variant carriers.Methods:In the first cohort of this case-control study,we performed whole-exome sequencing in 1555 patients with early-onset or familial PD and 2234 healthy controls;then in the second cohort,whole-genome sequencing was performed in sporadic late-onset PD samples(1962 patients),as well as 1279 controls.Variants at target GCH1 regions were extracted,and then genetic and detailed phenotypic data were analyzed using regression models and the sequence kernel association test.We also performed a meta-analysis to correlate deleterious GCH1 variants with age at onset(AAO)in PD patients.Results:For coding variants,we identified a significant burden of GCH1 deleterious variants in early-onset or familial PD cases compared to controls(1.2%VS 0.1%,P<0.0001).In the analysis of possible regulatory variants in GCH1 non-coding regions,rs12323905(P=0.001,odds ratio=1.19,95%CI 1.07-1.32)was significantly associated with PD,and variant sets in untranslated regions and intron regions,GCH1 brain-specific expression quantitative trait loci,and two possible promoter/enhancer(GH14J054857 and GH14J054880)were suggestively associated with PD.Genotype phenotype correlation analysis revealed that the carriers of GCH1 deleterious variants manifested younger AAO(P<0.0001),and had milder motor symptoms,milder fatigue symptoms and more autonomic nervous dysfunctions.Meta-analysis of six studies demonstrated 6.4-year earlier onset in GCH1 deleterious variant carriers(P=0.0009).Conclusions:The results highlight the importance of deleterious variants and non-coding variants of GCH1 in PD in Chinese mainland and suggest that GCH1 mutation can influence the PD phenotype,which may help design experimental studies to elucidate the mechanisms of GCH1 in the pathogenesis of PD.展开更多
基金supported by the Natural Science Foundation of Sichuan Province,China(Nos.2022NSFSC0034 and 2022NSFSC1901)the National Railway Group Science and Technology Program(No.N2021J028)+1 种基金the Independent Research and Development Projects of State Key Laboratory of Heavy Duty AC Drive Electric Locomotive Systems Integration(No.R111720H01385)the Independent Research and Development Projects of State Key Laboratory of Traction Power(No.2022TPL-T02),China。
文摘In this paper,a numerical simulation model of the flow field in a gearbox with an oil volume adjusting device is established for the first time to study its influence on the lubrication characteristics of a high-speed electric multiple unit(EMU)gearbox.The moving particle semi-implicit(MPS)method is used to numerically simulate the internal flow field of the gearbox of the high-speed EMU under working conditions.The effects of the velocity of the high-speed EMU,the immersion depth,and the oil sump temperature on the power loss of the gears and the lubricant quantity of each bearing are studied and provide an effective tool for the quantitative evaluation of the lubrication characteristics of the gearbox.The lubrication characteristics of the gearbox under different working conditions are studied when the oil volume adjusting device is closed and opened.The results show that the oil volume adjusting device mainly changes the amount of lubricant stirred by the output gear by changing the flow rate of lubricant from the cavity pinion(Cavity P)to the cavity gear(Cavity G),and thus affects the power loss of gears and the lubricant quantity of each bearing.
基金Project supported by the National Natural Science Foundation of China(Nos.51675443 and 51735012)the Independent Research and Development Projects of State Key Laboratory of Traction Power,Southwest Jiaotong University,China(Nos.2017TPL_T02 and2018TPL_T05)
基金This study was supported by the National Key Research and Development Program of China(2016YFC1306000,2017YFC0909100,2018YFC1312000,and 2016YFC1306501)to GJ.F,T.B.S and Y.X.X,the Central Public-Interest Scientific Institution Basal Research Fund of Chinese Academy of Medical Sciences(2018-12 M-HL-025)+3 种基金to GJ.F,the National Natural Science Foundation of China(81873785,81974202)to GJ.F and T.B.S,and Science and Technology Major Project of Hunan Provincial Science and Technology Department(2018SK1030)to GJ.F,the innovative team program from Department of Sci-ence&Technology of Hunan Province(2019RS1010)to GJ.F,and the Innovation-driven Team Project from Central South University(2020CX016)to GJ.F.
文摘Background:Common and rare variants of guanosine triphosphate cyclohydrolase 1(GCH1)gene may play important roles in Parkinson's disease(PD).However,there is a lack of comprehensive analysis of GCH1 genotypes,especially in non-coding regions.The aim of this study was to explore the genetic characteristics of GCH1,including rare and common variants in coding and non-coding regions,in a large population of PD patients in Chinese mainland,as well as the phenotypic characteristics of GCH1 variant carriers.Methods:In the first cohort of this case-control study,we performed whole-exome sequencing in 1555 patients with early-onset or familial PD and 2234 healthy controls;then in the second cohort,whole-genome sequencing was performed in sporadic late-onset PD samples(1962 patients),as well as 1279 controls.Variants at target GCH1 regions were extracted,and then genetic and detailed phenotypic data were analyzed using regression models and the sequence kernel association test.We also performed a meta-analysis to correlate deleterious GCH1 variants with age at onset(AAO)in PD patients.Results:For coding variants,we identified a significant burden of GCH1 deleterious variants in early-onset or familial PD cases compared to controls(1.2%VS 0.1%,P<0.0001).In the analysis of possible regulatory variants in GCH1 non-coding regions,rs12323905(P=0.001,odds ratio=1.19,95%CI 1.07-1.32)was significantly associated with PD,and variant sets in untranslated regions and intron regions,GCH1 brain-specific expression quantitative trait loci,and two possible promoter/enhancer(GH14J054857 and GH14J054880)were suggestively associated with PD.Genotype phenotype correlation analysis revealed that the carriers of GCH1 deleterious variants manifested younger AAO(P<0.0001),and had milder motor symptoms,milder fatigue symptoms and more autonomic nervous dysfunctions.Meta-analysis of six studies demonstrated 6.4-year earlier onset in GCH1 deleterious variant carriers(P=0.0009).Conclusions:The results highlight the importance of deleterious variants and non-coding variants of GCH1 in PD in Chinese mainland and suggest that GCH1 mutation can influence the PD phenotype,which may help design experimental studies to elucidate the mechanisms of GCH1 in the pathogenesis of PD.
