Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely u...Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely used practice in public buildings throughout China, including government offices, schools and hospitals. To investigate the damage mechanism of suspended ceilings, a series of three-dimensional shake table tests was conducted to reproduce the observed damage. A full-scale reinforced concrete frame was constructed as the testing frame for the ceiling, which was single-story and infilled with brick masonry walls to represent the local construction of low-rise buildings. In general, the ceiling in the tests exhibited similar damage phenomena as the field observations, such as higher vulnerability of perimeter elements and extensive damage to the cross runners. However, it exhibited lower fragility in terms of peak ground/roof accelerations at the initiation of damage. Further investigations are needed to clarify the reasons for this behavior.展开更多
Purpose : To compare the clinical application value of Ultrasound biomicrsocpic dark room provocative test with the traditional dark room test in screening primary angle closure glaucoma (PACG).Methods: 22 eyes with P...Purpose : To compare the clinical application value of Ultrasound biomicrsocpic dark room provocative test with the traditional dark room test in screening primary angle closure glaucoma (PACG).Methods: 22 eyes with PACG in prodromal stage and 30 eyes with deep anterior chamber and wide angle of 15 normal persons were observed in this trail. All 52 eyes were performed traditional dark room provocative test and ultrasound biomicorosopic darkroom test respectively. With different positive diagnostic criteria, the sensitivity of the two methods were compared using chi-squared analysis.Results : After staying in the dark room for 2 hours, In case group, IOP in 10 of 22 eyes rose more than 1. 07kPa(1kPa = 7.5mmHg), in 12 eyes less than 1.07kPa or had no changes; appositional angle closure were found by Goldmann gonioscopy in 8 eyes : 3 eyes in two quadrants, 5 eyes in more than two quadrants; the appositional angle closure was found by UBM in 15 eyes; 3 eyes in one quadrants, 5 eyes in two quadrants, 7展开更多
为有效表征流体在致密储层CO_(2)驱动态裂缝网络系统的分区闭合及动态储容效应,以及反演动态裂缝网络特征参数,建立一种动态裂缝网络水平井试井模型,采用半解析方法、Laplace转换、动态裂缝特征函数、杜哈美原理和Stehfest数值反演求解...为有效表征流体在致密储层CO_(2)驱动态裂缝网络系统的分区闭合及动态储容效应,以及反演动态裂缝网络特征参数,建立一种动态裂缝网络水平井试井模型,采用半解析方法、Laplace转换、动态裂缝特征函数、杜哈美原理和Stehfest数值反演求解试井模型,获得井底压力响应半解析解,绘制井底压力响应曲线,对动态裂缝闭合速度、井筒储集系数、动态裂缝网络半径和动态储容比进行敏感性分析。结果表明:考虑致密储层CO_(2)驱动态裂缝网络的压力图版与常规压力图版存在显著差异;井底压力响应曲线呈异常尖峰和额外双水平线特征,ψ′wD t D<0.5;动态裂缝闭合速度、动态裂缝网络半径及动态储容比对井底压力响应影响较大。动态裂缝网络水平井试井模型能有效定量表征致密储层长期注入CO_(2)的动态裂缝网络行为及非稳态渗流规律,为CO_(2)强化致密储层开发提供依据。展开更多
目的:冻干疫苗在不破坏原有免疫原性的基础上使该致病微生物无致病性,为避免氧气导致冻干疫苗的降解、药物的失活,需对其真空度进行检测。方法:基于朗伯比尔定律,灯检机使用顶空气体分析法(Headspace Gas Analysis,HGA)对冻干疫苗制品...目的:冻干疫苗在不破坏原有免疫原性的基础上使该致病微生物无致病性,为避免氧气导致冻干疫苗的降解、药物的失活,需对其真空度进行检测。方法:基于朗伯比尔定律,灯检机使用顶空气体分析法(Headspace Gas Analysis,HGA)对冻干疫苗制品真空度逐瓶检测,针对灯检机HGA站位详述了其硬件调试及参数设定的方法。结果:灯检机HGA检测能力主要由其设备硬件和参数控制,同时还受制品慢散性、温度、湿度、内包材和生产工艺的影响。结论:通过灯检机HGA站位的应用,确保了冻干疫苗制品的密封完整性,保证了冻干疫苗制品的质量。展开更多
This paper presents an approach to algebraic detection of relative form closure for a multi-fingered grasp G and gives an attention to the classification of relative form closures.Whether or not a grasp G is of relati...This paper presents an approach to algebraic detection of relative form closure for a multi-fingered grasp G and gives an attention to the classification of relative form closures.Whether or not a grasp G is of relative form closure has been verified by the geometric criterion 0?rintC[G](Xiong Y L,Xiong X R.Algebraic structure and geometric interpretation of rigid complex fixture system.IEEE Trans Autom Sci Eng,2007,4:252–264;Xiong Y L.Theory of point contact restraint and qualitative analysis of robot grasping.Sci China Ser A-Math,1994,37:629–640).Our aim is at transferring the geometric criterion into an algebraic formulation by a theorem that a grasp G is relative form closure,if,and only if the origin 0 can be represented as a positive convex combination of G.So we develop a constructive procedure called ri-simplex algorithm to find a positive convex combination of G when it has relative form closure.Form closure is considered as a special case of relative form closure,when the grasp G can affinely span the whole space,while partly relative form closure is referred to as form closed relative to a subset G1 of G.展开更多
基金Research fund for earthquake engineering of China Earthquake Administration(201508023)a project of the National Science&Technology Support Program during the Twelfth Five-year Plan Period of China(2015BAK17B03)a general program of National Natural Science Foundation of China(51578515)
文摘Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely used practice in public buildings throughout China, including government offices, schools and hospitals. To investigate the damage mechanism of suspended ceilings, a series of three-dimensional shake table tests was conducted to reproduce the observed damage. A full-scale reinforced concrete frame was constructed as the testing frame for the ceiling, which was single-story and infilled with brick masonry walls to represent the local construction of low-rise buildings. In general, the ceiling in the tests exhibited similar damage phenomena as the field observations, such as higher vulnerability of perimeter elements and extensive damage to the cross runners. However, it exhibited lower fragility in terms of peak ground/roof accelerations at the initiation of damage. Further investigations are needed to clarify the reasons for this behavior.
文摘Purpose : To compare the clinical application value of Ultrasound biomicrsocpic dark room provocative test with the traditional dark room test in screening primary angle closure glaucoma (PACG).Methods: 22 eyes with PACG in prodromal stage and 30 eyes with deep anterior chamber and wide angle of 15 normal persons were observed in this trail. All 52 eyes were performed traditional dark room provocative test and ultrasound biomicorosopic darkroom test respectively. With different positive diagnostic criteria, the sensitivity of the two methods were compared using chi-squared analysis.Results : After staying in the dark room for 2 hours, In case group, IOP in 10 of 22 eyes rose more than 1. 07kPa(1kPa = 7.5mmHg), in 12 eyes less than 1.07kPa or had no changes; appositional angle closure were found by Goldmann gonioscopy in 8 eyes : 3 eyes in two quadrants, 5 eyes in more than two quadrants; the appositional angle closure was found by UBM in 15 eyes; 3 eyes in one quadrants, 5 eyes in two quadrants, 7
文摘为有效表征流体在致密储层CO_(2)驱动态裂缝网络系统的分区闭合及动态储容效应,以及反演动态裂缝网络特征参数,建立一种动态裂缝网络水平井试井模型,采用半解析方法、Laplace转换、动态裂缝特征函数、杜哈美原理和Stehfest数值反演求解试井模型,获得井底压力响应半解析解,绘制井底压力响应曲线,对动态裂缝闭合速度、井筒储集系数、动态裂缝网络半径和动态储容比进行敏感性分析。结果表明:考虑致密储层CO_(2)驱动态裂缝网络的压力图版与常规压力图版存在显著差异;井底压力响应曲线呈异常尖峰和额外双水平线特征,ψ′wD t D<0.5;动态裂缝闭合速度、动态裂缝网络半径及动态储容比对井底压力响应影响较大。动态裂缝网络水平井试井模型能有效定量表征致密储层长期注入CO_(2)的动态裂缝网络行为及非稳态渗流规律,为CO_(2)强化致密储层开发提供依据。
文摘目的:冻干疫苗在不破坏原有免疫原性的基础上使该致病微生物无致病性,为避免氧气导致冻干疫苗的降解、药物的失活,需对其真空度进行检测。方法:基于朗伯比尔定律,灯检机使用顶空气体分析法(Headspace Gas Analysis,HGA)对冻干疫苗制品真空度逐瓶检测,针对灯检机HGA站位详述了其硬件调试及参数设定的方法。结果:灯检机HGA检测能力主要由其设备硬件和参数控制,同时还受制品慢散性、温度、湿度、内包材和生产工艺的影响。结论:通过灯检机HGA站位的应用,确保了冻干疫苗制品的密封完整性,保证了冻干疫苗制品的质量。
基金supported by the National Natural Science Foundation of China(Grant No.51327801)the National Key Basic Research Program of China(Grant No.2013CB035803)
文摘This paper presents an approach to algebraic detection of relative form closure for a multi-fingered grasp G and gives an attention to the classification of relative form closures.Whether or not a grasp G is of relative form closure has been verified by the geometric criterion 0?rintC[G](Xiong Y L,Xiong X R.Algebraic structure and geometric interpretation of rigid complex fixture system.IEEE Trans Autom Sci Eng,2007,4:252–264;Xiong Y L.Theory of point contact restraint and qualitative analysis of robot grasping.Sci China Ser A-Math,1994,37:629–640).Our aim is at transferring the geometric criterion into an algebraic formulation by a theorem that a grasp G is relative form closure,if,and only if the origin 0 can be represented as a positive convex combination of G.So we develop a constructive procedure called ri-simplex algorithm to find a positive convex combination of G when it has relative form closure.Form closure is considered as a special case of relative form closure,when the grasp G can affinely span the whole space,while partly relative form closure is referred to as form closed relative to a subset G1 of G.
