The Yemaomian landslide,the largest near-dam accumulation landslide in the Three Gorges Reservoir area,is situated 17 km upstream of the Three Gorges Dam.Nearly 20 years of monitoring data indicate that the landslide ...The Yemaomian landslide,the largest near-dam accumulation landslide in the Three Gorges Reservoir area,is situated 17 km upstream of the Three Gorges Dam.Nearly 20 years of monitoring data indicate that the landslide has been undergoing slow deformation with a low deformation rate and magnitude.This paper applies a stepwise linear regression method and a mechanical model of hydrodynamics triggering to deeply explore the relationship between geological conditions,external factors,and deformation characteristics.Based on the stage transition characteristics of external triggering factors,the deformation evolution process of the landslide since the reservoir impoundment is divided into three stages:(1)June 2003-September 2006,the landslide was reactivated by the significant rise in reservoir water levels,in a retrogressive mode;(2)October 2006-September 2018,the deformation mode shifted from retrogressive mode to creep deformation as a whole,primarily due to the degradation effect on the landslide mass caused by immersion in reservoir water.(3)October 2018-February 2024,a further significant reduction in the overall deformation rate and the impact of seasonal rainfall on landslide deformation surpassed that of reservoir water level fluctuations.The main component of landslide deformation is convergent creep,and extreme rainfall will be an important triggering factor for the local instability.Identifying the deformation evolution stages and determining the dominant external influencing factors at each stage is crucial for landslide research,and this paper provides an effective research paradigm for this purpose.展开更多
Tight-skin （TSK） mice are commonly used as an animal model to study the pathogenesis of Marfan syndrome （MFS）, but little is known of their skeletal phenotype and in particular of the development of the spinal def...Tight-skin （TSK） mice are commonly used as an animal model to study the pathogenesis of Marfan syndrome （MFS）, but little is known of their skeletal phenotype and in particular of the development of the spinal deformities, common in MFS. Here we examined growth of the axial skeletons of TSK and wild-type（B6） mice during their period of rapid growth. The whole bodies of mice, 4-12 weeks of age, were scanned after sacrifice, by micro-computed tomography （microCT）. We reconstructed three-dimensional models of the spine and ribs, and measured vertebral body heights and rib lengths using the Mac-based image-processing software ＂OsiriX＂. Although the TSK mice were smaller than the B6 mice at 4 weeks, they experienced an early growth spurt and by 8 weeks the height, but not the width, of the vertebral body was significantly greater in the TSK mice than the B6 mice. Measurement of the angles of scoliotic and kyphotic curves postmortem in the mice was problematic, hence we measured changes that develop in skeletal elements in these disorders. As a marker of kyphosis, we measured anterior wedging of the vertebral bodies; as a marker for scoliosis we measured asymmetries in rib length. We found, unlike in the B6 mice where the pattern was diffuse, wedging in TSK mice was directly related to spinal level and peaked steeply at the thoracolumbar junction. There was also significant asymmetry in length of the ribs in the TSK mice, but not in the B6 mice. The TSK mice thus appear to exhibit spinal deformities seen in MFS and could be a useful model for gaining understanding of the mechanisms of development of scoliosis and kyphosis in this disorder.展开更多
The BPA eight-chain molecular network model is introduced into the finite element formulation of elastic-plastic large deformation. And then, the tensile deformation localization development of the amorphous glassy ci...The BPA eight-chain molecular network model is introduced into the finite element formulation of elastic-plastic large deformation. And then, the tensile deformation localization development of the amorphous glassy circular polymeric bars (such as polycarbonates) is numerically simulated. The simulated results are compared with experimental ones, and very good consistence between numerical simulation and experiment is obtained, which shows the efficiency of the finite element analysis. Finally, the influences of the microstructure parameter S-ss on tensile neck-propagation and triaxial stress effect are studied.展开更多
The development of oral orthodontic disciplines of Jinzhou Medical College Department of Oral Zhang Yuxia any subject development and other disciplines are closely related to the development of orthodontics is no exce...The development of oral orthodontic disciplines of Jinzhou Medical College Department of Oral Zhang Yuxia any subject development and other disciplines are closely related to the development of orthodontics is no exception, which can be obtained from its development process prove. Initially used to treat orthodontic patients with precious metals, because of the expensive, very few people acceptable. Later, materials scientists and orthodontists through.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U2340226,12072047,42277186)China Three Gorges Corporation under the contract of No.0799291(SXSN/5115)the Fundamental Research Funds for Central Public Welfare Research Institutes(CKSF20241014/YT,CKSF20241016/YT).
文摘The Yemaomian landslide,the largest near-dam accumulation landslide in the Three Gorges Reservoir area,is situated 17 km upstream of the Three Gorges Dam.Nearly 20 years of monitoring data indicate that the landslide has been undergoing slow deformation with a low deformation rate and magnitude.This paper applies a stepwise linear regression method and a mechanical model of hydrodynamics triggering to deeply explore the relationship between geological conditions,external factors,and deformation characteristics.Based on the stage transition characteristics of external triggering factors,the deformation evolution process of the landslide since the reservoir impoundment is divided into three stages:(1)June 2003-September 2006,the landslide was reactivated by the significant rise in reservoir water levels,in a retrogressive mode;(2)October 2006-September 2018,the deformation mode shifted from retrogressive mode to creep deformation as a whole,primarily due to the degradation effect on the landslide mass caused by immersion in reservoir water.(3)October 2018-February 2024,a further significant reduction in the overall deformation rate and the impact of seasonal rainfall on landslide deformation surpassed that of reservoir water level fluctuations.The main component of landslide deformation is convergent creep,and extreme rainfall will be an important triggering factor for the local instability.Identifying the deformation evolution stages and determining the dominant external influencing factors at each stage is crucial for landslide research,and this paper provides an effective research paradigm for this purpose.
基金funding for support of this research from the British Scoliosis Research Foundation (JU, JY)the China Postdoctoral Science Foundation (2012M520584)Tianjin Postdoctoral Science Foundation (BL)
文摘Tight-skin （TSK） mice are commonly used as an animal model to study the pathogenesis of Marfan syndrome （MFS）, but little is known of their skeletal phenotype and in particular of the development of the spinal deformities, common in MFS. Here we examined growth of the axial skeletons of TSK and wild-type（B6） mice during their period of rapid growth. The whole bodies of mice, 4-12 weeks of age, were scanned after sacrifice, by micro-computed tomography （microCT）. We reconstructed three-dimensional models of the spine and ribs, and measured vertebral body heights and rib lengths using the Mac-based image-processing software ＂OsiriX＂. Although the TSK mice were smaller than the B6 mice at 4 weeks, they experienced an early growth spurt and by 8 weeks the height, but not the width, of the vertebral body was significantly greater in the TSK mice than the B6 mice. Measurement of the angles of scoliotic and kyphotic curves postmortem in the mice was problematic, hence we measured changes that develop in skeletal elements in these disorders. As a marker of kyphosis, we measured anterior wedging of the vertebral bodies; as a marker for scoliosis we measured asymmetries in rib length. We found, unlike in the B6 mice where the pattern was diffuse, wedging in TSK mice was directly related to spinal level and peaked steeply at the thoracolumbar junction. There was also significant asymmetry in length of the ribs in the TSK mice, but not in the B6 mice. The TSK mice thus appear to exhibit spinal deformities seen in MFS and could be a useful model for gaining understanding of the mechanisms of development of scoliosis and kyphosis in this disorder.
文摘The BPA eight-chain molecular network model is introduced into the finite element formulation of elastic-plastic large deformation. And then, the tensile deformation localization development of the amorphous glassy circular polymeric bars (such as polycarbonates) is numerically simulated. The simulated results are compared with experimental ones, and very good consistence between numerical simulation and experiment is obtained, which shows the efficiency of the finite element analysis. Finally, the influences of the microstructure parameter S-ss on tensile neck-propagation and triaxial stress effect are studied.
文摘The development of oral orthodontic disciplines of Jinzhou Medical College Department of Oral Zhang Yuxia any subject development and other disciplines are closely related to the development of orthodontics is no exception, which can be obtained from its development process prove. Initially used to treat orthodontic patients with precious metals, because of the expensive, very few people acceptable. Later, materials scientists and orthodontists through.
