A rockbolt acting in the rock mass is subjected to the combined action of the pull-out load and confining pressure, and the bond quality of the rockbolt directly affects the stability of the roadway and cavern. Theref...A rockbolt acting in the rock mass is subjected to the combined action of the pull-out load and confining pressure, and the bond quality of the rockbolt directly affects the stability of the roadway and cavern. Therefore, in this study, confining pressure and pull-out load are applied to grouted rockbolt systems with bond defects by a numerical simulation method, and the rockbolt is detected by ultrasonic guided waves to study the propagation law of ultrasonic guided waves in defective rockbolt systems and the bond quality of rockbolts under the combined action of pull-out load and confining pressure. The numerical simulation results show that the length and location of bond defects can be detected by ultrasonic guided waves under the combined action of pull-out load and confining pressure. Under no pull-out load, with increasing confining pressure, the low-frequency part of the guided wave frequency in the rockbolt increases, the high-frequency part decreases, the weakening effect of the confining pressure on the guided wave propagation law increases, and the bond quality of the rockbolt increases. The existence of defects cannot change the strengthening effect of the confining pressure on the guided wave propagation law under the same pull-out load or the weakening effect of the pull-out load on the guided wave propagation law under the same confining pressure.展开更多
A new species,Lepidodens huadingensis Guo&Pan sp.nov.,was collected from Zhejiang Province.This is the most northern record of a species in this genus.This new species is identified by a narrow longitudinal stripe...A new species,Lepidodens huadingensis Guo&Pan sp.nov.,was collected from Zhejiang Province.This is the most northern record of a species in this genus.This new species is identified by a narrow longitudinal stripe on lateral side from head to thoracic segment Ⅲ,a labial chaetal formula of M_(1)M_(2)R(R_(2))EL_(1)L_(2),dorsal abdominal segments Ⅰ-Ⅲ with 3/6/7 mac,and two smooth chaetae on posterior face of ventral tube.A detailed comparison among four recorded species,a key to species of this genus were provided.展开更多
Background:Hearing loss(HL)is one major cause of disability and can lead to social impairments.However,the relationship between loneliness and the risk of incident HL remains unclear.Our study aimed to investigate thi...Background:Hearing loss(HL)is one major cause of disability and can lead to social impairments.However,the relationship between loneliness and the risk of incident HL remains unclear.Our study aimed to investigate this association among adults in the UK.Methods:This cohort study was based on data from the UK Biobank study.Loneliness was assessed by asking participants if they often felt lonely.Incident HL was defined as a primary diagnosis,ascertained via linkage to electronic health records.Cox proportional hazard regression models were used to examine the association between loneliness and risk of incident HL.Results:Our analyses included 490,865 participants[mean(SD)age,56.5(8.1)years;54.4%female],among whom 90,893(18.5%)reported feeling lonely at baseline.Over a median follow-up period of 12.3 years(interquartile range,11.3 to 13.1),11,596 participants were diagnosed with incident HL.Compared to non-lonely participants,lonely individuals exhibited an increased risk of HL[hazard ratio(HR),1.36;95%confidence interval(CI),1.30 to 1.43].This association remained(HR,1.24;95%CI,1.17 to 1.31)after adjusting for potential confounders,including age,sex,socioeconomic status,biological and lifestyle factors,social isolation,depression,chronic diseases,use of ototoxic drugs,and genetic risk of HL.The joint analysis showed that loneliness was significantly associated with an increased risk of incident HL across all levels of genetic risks for HL.Conclusions:Loneliness was associated with the risk of incident HL independent of other prominent risk factors.Social enhancement strategies aimed at alleviating loneliness may prove beneficial in HL prevention.展开更多
文摘A rockbolt acting in the rock mass is subjected to the combined action of the pull-out load and confining pressure, and the bond quality of the rockbolt directly affects the stability of the roadway and cavern. Therefore, in this study, confining pressure and pull-out load are applied to grouted rockbolt systems with bond defects by a numerical simulation method, and the rockbolt is detected by ultrasonic guided waves to study the propagation law of ultrasonic guided waves in defective rockbolt systems and the bond quality of rockbolts under the combined action of pull-out load and confining pressure. The numerical simulation results show that the length and location of bond defects can be detected by ultrasonic guided waves under the combined action of pull-out load and confining pressure. Under no pull-out load, with increasing confining pressure, the low-frequency part of the guided wave frequency in the rockbolt increases, the high-frequency part decreases, the weakening effect of the confining pressure on the guided wave propagation law increases, and the bond quality of the rockbolt increases. The existence of defects cannot change the strengthening effect of the confining pressure on the guided wave propagation law under the same pull-out load or the weakening effect of the pull-out load on the guided wave propagation law under the same confining pressure.
基金supported by the Zhejiang Provincial Natural Science Foundation (LTY20C030001)the Project for Investigation of Wild Animal Diversity in Tiantai County。
文摘A new species,Lepidodens huadingensis Guo&Pan sp.nov.,was collected from Zhejiang Province.This is the most northern record of a species in this genus.This new species is identified by a narrow longitudinal stripe on lateral side from head to thoracic segment Ⅲ,a labial chaetal formula of M_(1)M_(2)R(R_(2))EL_(1)L_(2),dorsal abdominal segments Ⅰ-Ⅲ with 3/6/7 mac,and two smooth chaetae on posterior face of ventral tube.A detailed comparison among four recorded species,a key to species of this genus were provided.
基金supported by the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(grant number 2020QNRC001 to Y.X.)the LiaoNing Revitalization Talents Program(grant number XLYC2203168 to Y.X.)+1 种基金the 345 Talent Project of Shengjing Hospital of China Medical University(grant number M0294 to Y.X.)the Scientific Research Project of the Liaoning Province Education Department(grant number LJKMZ20221149 to Y.X.).
文摘Background:Hearing loss(HL)is one major cause of disability and can lead to social impairments.However,the relationship between loneliness and the risk of incident HL remains unclear.Our study aimed to investigate this association among adults in the UK.Methods:This cohort study was based on data from the UK Biobank study.Loneliness was assessed by asking participants if they often felt lonely.Incident HL was defined as a primary diagnosis,ascertained via linkage to electronic health records.Cox proportional hazard regression models were used to examine the association between loneliness and risk of incident HL.Results:Our analyses included 490,865 participants[mean(SD)age,56.5(8.1)years;54.4%female],among whom 90,893(18.5%)reported feeling lonely at baseline.Over a median follow-up period of 12.3 years(interquartile range,11.3 to 13.1),11,596 participants were diagnosed with incident HL.Compared to non-lonely participants,lonely individuals exhibited an increased risk of HL[hazard ratio(HR),1.36;95%confidence interval(CI),1.30 to 1.43].This association remained(HR,1.24;95%CI,1.17 to 1.31)after adjusting for potential confounders,including age,sex,socioeconomic status,biological and lifestyle factors,social isolation,depression,chronic diseases,use of ototoxic drugs,and genetic risk of HL.The joint analysis showed that loneliness was significantly associated with an increased risk of incident HL across all levels of genetic risks for HL.Conclusions:Loneliness was associated with the risk of incident HL independent of other prominent risk factors.Social enhancement strategies aimed at alleviating loneliness may prove beneficial in HL prevention.
