电梯试验塔井道高度与试验电梯最大速度的关系

正电梯试验塔用于模拟电梯实际运行环境,对电梯整机及安全部件的安全性和可靠性进行型式试验,如电梯运行速度测试、加减速度测试、振动加速度的测试、运行噪声测试、平衡系数测试、制动能力试验、安全钳、限速器、缓冲器、上行超速保护装置等试验。电梯型式试验机构能够试验电梯的最大额定速度是其型式试验能力的一个重要指标,也是核定制造单位试验能力的重要依据。试验电梯的速度与电梯试验塔的提升高度有关,速度越大,需要的试验塔的提升     

地基差异沉降下埋地管道的有限元分析与试验研究

利用大型数值模拟仿真软件ABAQUS对地基差异沉降下的埋地管道力学性状进行了分析,找出了管道受力较大的区域.采用电测法对地基差异沉降下的埋地管道受力状况进行现场测试,结果表明,有限元计算结果与试验吻合良好.对管道每隔一个月连续进行4次应力测试,得知地基差异沉降下管道所受的应力远小于管道材料的许用应力.分析了埋地管道受力影响因素.可以为地基差异沉降下埋地管道最大应力区的有效防护提供参考.     

斜拉桥支架法施工的自适应安全监测技术

介绍自适应控制的基本原理及其运用现状。根据斜拉桥的实际情况选用自适应控制形式,在主要部位埋设传感器和相关的测试仪器,明确监测时间并在实施中严格执行。依据实测结果对标高、应力、容重等参数按实际情况进行修正,得出施工过程中的受力状态,从而调整施工。算出主梁各节点理论施工预拱度变化曲线等数据并与实测值进行比较,反复修正。自适应法达到了仿真计算与实际施工过程保持一致的最佳施工控制效果。绥芬河斜拉桥的施工证明,自适应法是一种很适合斜拉桥支架施工安全监测的技术,值得推广应用。     

加载条件下多尺寸原水管道受力特征模型试验

为解决在施工过程中管线附近超载导致的爆管问题,分析堆载对不同管径原水管线受力变形的影响,基于模型试验研究管道的受力变形特征,并通过数值模拟计算对试验结果进行论证。结果表明:有限元计算结果与试验结果较吻合,管底整体应力值大于管腰处;在相同荷载作用下,随着管道直径的不断增大,管道所受的应力值越来越小;当荷载距离管轴线较远时,管道整体应力值变小;对比发现,随着加载值逐渐增大、管径逐渐变小,管体轴向应力值逐渐增大,且应力值增长速度较快。这主要是因为小管径的管道长细比较大,在土体中受约束较强,其所受到的应力值较大,容易产生破坏,实际施工时需要注意此类问题。     

电力组塔专用起重设备安全施工的技术方案研究

针对目前组立钢管塔所采用的组塔专用起重设备,提出了一些组塔专用起重设备的基础、标准节、顶升方案、设备本体腰箍、底座轨道、控制系统、监测及对讲系统等相关技术的实施方案,以及通过拆分质量较大的塔件进行吊装组塔的施工方案,以确保组塔施工的安全性。     

用于预应力筋长期实时应力监测的光纤传感测试技术研究

预应力筋是预应力混凝土结构中的关键受力构件,对其应力状态的监测具有重大意义。针对传统测试方法难以有效解决其应力分布测试问题的现状,提出基于光纤布拉格光栅传感测试技术的预应力筋长期实时应力监测方法。设计模拟张拉装置,并构建预应力钢筋的光纤光栅应变测试系统,进行模拟试验研究,其试验结果表明,该测试系统适合于预应力筋的工作环境,具有线性度高、重复性好,且不影响基体性能的特点。此外,针对预应力钢绞线的特殊结构和工作特点,提出具有温度补偿能力的锚端光纤布拉格光栅应力传感测试方案,并进行理论分析。研究结果验证了光纤光栅传感技术用于预应力筋应力测试的可行性,并为其实际工程应用奠定了基础。     

基于氢气充放试验及数值模拟的储氢气瓶安全评价

储氢气瓶是新能源汽车的重要储能设备,其可靠性直接关系到汽车的安全性。研究了不同环境温度下,35 MPa铝合金内胆车用储氢III型气瓶在充放气时的最终温度和应力分布情况,并对其安全性进行了评价。借助试验测试平台,在不同温度下进行了实际充放试验。试验过程中无漏气现象,且最终温度符合要求,表明储氢气瓶在试验条件下是安全的。由此,在获得了储氢气瓶充放时热响应规律的基础上,对不同温度下的氢气充放过程进行了数值模拟,得到其应力分布情况。结果表明,储氢气瓶复合层的应力远小于其材料抗拉强度,即内胆和复合层的强度均可视为满足要求。研究结果可为储氢气瓶的试验开展、安全评价、寿命预测提供依据。     

平头塔机起重臂断裂失效分析

本文以一台QTZ125平头塔式起重机的起重臂与平衡臂连接节(以下简称A节)为研究对象,对该节使用中发生的主要受力杆件失效断裂进行理论分析与试验测试。采用ANSYS力学分析模块对塔机起重臂和平衡臂节建模分析,模拟塔机使用工况下A节主要受力杆件的受力情况,经计算得出断裂杆件及焊接部位局部应力过大。为了验证建模分析的可信度,对同型号塔机A节断裂杆件及其相邻主要受力杆件进行动态应变测试,测试结果与模型分析结果相一致。本文提出了有效降低失效杆件局部应力的维修方案及其优化结构设计的建议。     

超超临界锅炉蒸汽安全阀试验手段探讨

系统分析了安全阀型式试验和性能试验相关国内外标准。针对国产超超临界安全阀新产品研发、安全阀整定压力准确度对发电机组安全性影响、现场实跳整定试验对机组运行的影响,阐述了国内超超临界火力发电机组蒸汽安全阀试验技术的滞后问题。认为有必要建设模拟超超临界锅炉实际介质参数的试验装置。     

浅埋煤层综放开采上覆岩层活动规律相似模拟试验

浅埋煤层综放开采因煤层埋藏浅、采出空间大,上覆岩层活动规律仍不清楚。以辛安矿1402工作面为研究对象,采用试验研究的方法建立相似模拟试验模型,研究放顶煤开采过程覆岩破断、沉降规律和覆岩应力演化及模拟液压支架受力等规律。试验结果表明:辛安矿1402工作面放顶煤开采初次来压来压步距是73m、周期性来压步距是31.5m、垮落角是59°;支架工作阻力88%分布在5000~7000kN,且分布呈现正弦波形,分布合理;上覆岩层垮落后在采空区内可形成"应力拱"结构,拱脚的应力大,沉降量多,应力拱结构支撑上覆垮落岩层;老顶垮落后可形成铰接结构,形成铰接结构的岩层旋转的角度可以通过函数公式计算。     

The effects of arm posture and holding time on holding capability and muscle activity

The aim of this study was to examine the effects of arm posture and holding time on human holding capability and resulting muscle activity. Fifteen healthy young males were recruited as participants. Maximum holding capacity was examined at 0 (degrees of shoulder forward flexion angle)/90 (degrees of elbow angle), 30/120 and 90/180 arm postures. Maximum acceptable weight of holding was evaluated in three arm postures (0/90, 30/120, 90/180) by three holding times (10?s, 20?s, 30?s). The greatest and lowest maximum holding capacity or maximum acceptable weight of holding occurred at 0/90 and 90/180 arm postures, respectively. Maximum acceptable weight of holding decreased with increasing holding time. While holding maximum acceptable weights, the % of maximum voluntary contraction of brachioradialis, biceps brachii and erector spinae ranged from 14 to 44%, from 14 to 53% and from 25 to 36%, respectively.     

Influence of trunk muscle activity and stability in front and back holding

Purpose. A tandem carrying style is often used in the workplace, but carrying approaches are different for two people because of the holding load in the tandem posture. To understand these carrying styles, this study aimed to investigate the patterns of muscle activity and stability of the trunk influenced by front and back holding of a heavy load. Methods. Electromyography data of eight trunk and two hip muscles, as well as displacements of the trunk, were recorded for analysis while subjects stood statically holding a handle in the front and back of the body with and without load. Results. Without load, muscle activities during front holding mirrored those during back holding. With load, greater muscle activities were observed in the dorsal muscles of the trunk and lesser activities were noted in the ventral muscles in the two holding styles. More frequencies of trunk oscillations occurred in front holding with and without load. Conclusions. The results revealed that back holding of load created more stability of the upper body, whereas front holding resulted in more instability of the trunk.     

国务院关于特大安全事故行政责任追究的规定

中华人民共和国国务院令(第 30 2号 )　　现公布《国务院关于特大安全事故行政责任追究的规定》 ,自公布之日起施行。总理 :朱基2 0 0 1年 4月 2 1日　　　第一条　为了有效地防范特大安全事故的发生 ,严肃追究特大安全事故的行政责任 ,保障人民群众生命、财产安全 ,制定本规定。　　第二条　地方人民政府主要领导人和政府有关部门正职负责人对下列特大安全事故的防范、发生 ,依照法律、行政法规和本规定的规定有失职、渎职情形或者负有领导责任的 ,依照本规定给予行政处分 ;构成玩忽职守罪或者其他罪的 ,依法追究刑事责任 :　　 (一 )特…     

Endurance time,muscular activity and the hand/arm tremor for different exertion forces of holding

This study aimed to examine the effects of exertion force on endurance time, muscular activity and hand/arm tremor during holding. Fifteen healthy young males were recruited as participants. The independent variable was exertion force (20%, 40%, 60% and 80% maximum holding capacity). The dependent variables were endurance time, muscular activity and hand/arm tremor. The results showed that endurance time decreased with exertion force while muscular activity and hand/arm tremor increased with exertion force. Hand/arm tremor increased with holding time. Endurance time of 40%, 60% and 80% maximum holding capacity was approximately 22.7%, 12.0% and 5.6% of that of 20% maximum holding capacity, respectively. The rms (root mean square) acceleration of hand/arm tremor of the final phase of holding was 2.27-, 1.33-, 1.20- and 1.73-fold of that of the initial phase of holding for 20%, 40%, 60% and 80% maximum holding capacity, respectively.     

考虑等待位置的航空器交叉滑行冲突概率模型

为解决交叉道口冲突范围定义不完整等问题,提出了航空器交叉滑行冲突概率模型。该模型针对交叉滑行道结构特点,以T型交叉口为例,综合等待位置、机身长度、喷流范围等要素,扩展冲突区域,基于实时速度、位置变化构造冲突概率模型,并利用速度分布密度函数对模型求解。仿真验证表明:模型能计算不同运动状态的中型机在T型交叉口处的冲突概率,T型道口等待位置对冲突概率影响较大,等待位置较近将造成冲突判断延迟,等待位置较远会产生虚警误判,致使滑行中断。利用实际滑行轨迹验证,结果表明:模型能够再现T型道口上2架中型机滑行冲突产生、发展及解脱过程,计算结果与实际运行情况一致,能为管制员、飞行员提前判断冲突,及时采取措施提供依据。     

基于航空器高度保持性能的风险碰撞模型优化*

为提高Reich风险碰撞模型在“缩小垂直间隔”(Reduced Vertical Separation Minimum,RVSM)标准实施后的适用性。基于同一机型航空器的测高系统误差（Altimetry System Error,ASE）数据在超高空各高度层中并不服从相同分布且具有显著的统计学差异,针对现有的Reich模型对同一机型仍使用整个航空空域的ASE数值进行经验分布拟合的现状,对模型中ASE混合累积经验分布参数部分进行改进,添加高度层相关的参数,使原有仅根据机型进行累积的ASE经验分布细化为根据机型和高度层2部分进行累积。结果表明:改进后模型可准确体现ASE数据在不同高度层的差异性;采用改进的风险模型进行仿真计算,得到更加精确的结果;验证改进后模型的合理性和其在应用中的有效性。     

测量不确定度的评定及应用

根据我国计量技术规范JJF1059-1999<量不确定度评定与表示>,结合实验室检测质量控制的实际要求,讨论测量不确定度评定的概念、评价方法和应注意的问题,进行不确定度评定结果的实际运用,说明建立测量不确定度的评定程序及应用,是达到实验室检测质量控制和规范性管理的有效措施.     

A test and refinement of the equity sensitivity construct

This paper reports results from two studies that test a refinement of the equity sensitivity construct first in an experimental setting and second in a field setting. Results from Study 1 show that benevolents express tolerance for both overreward and underreward relative to entitleds and equity sensitives and that benevolents report relatively high levels of satisfaction regardless of reward condition. Study 1 results also show that manipulation of outcomes produce a more dramatic effect on satisfaction than does manipulation of inputs. Results from Study 2 reveal significantly different exchange ideologies for benevolents and entitleds and show that entitleds place more importance on pay whereas benevolents place more importance on the work itself. For both benevolents and entitleds, there is a positive correlation between assessments of distributive justice and job satisfaction. Implication of the findings both for equity theory research and the practice of management are discussed.     

Validation of the driver ecological glare test

IntroductionThe present study proposes to validate the Driver Ecological Glare Test (DEGT), a test developed to measure the benefit of a headlight glare Advanced Driver Assistance System (ADAS), by comparing it to a laboratory glare test. Method: Twenty-four participants, aged from 55 to 70 years, were recruited to complete a visual examination, including monocular halo size measurement for both eyes using Vision Monitor device (MonCv3; Metrovision). An on-field evaluation took place at night at the UTAC CERAM test track to obtain disability glare measures using the DEGT. Results: A significant correlation was found between the two glare tests and Bland-Altman analysis reveals a good agreement with a bias of 73.7 arcmin between the halo size measurements obtained from the DEGT and Vision Monitor. The results of the present study demonstrate that the DEGT is a valid method to test halo size and is adapted to evaluate the benefits of an antiglare device for drivers in an ecological situation.