稳定蓝相液晶的研究进展

介绍了蓝相液晶特殊的“双轴螺旋”结构,并解释了其三维晶格的形成.阐述了蓝相液晶在显示器件中的应用优势和原理.分类详细介绍了诸如聚合物稳定、纳米粒子稳定、“香蕉”型或“T”型分子诱发稳定、双液晶基元以及氢键稳定等拓宽蓝相温度范围的方法,分析了各自的特点和优势.最后对蓝相液晶的应用前景进行了展望.     

无人值守微波中继站远程短信报警系统

本文针对野外现场的特殊环境,结合通信业和短信业务的迅猛发展,通过手机短信发送报警信息这样一个有效的手段。真正实现机房从有人值守到少人或无人值守,保障设备稳定运行和机房安全。     

纳米功能镀膜技术在建筑节能中的应用

一、纳米功能镀膜技术简介纳米功能镀膜技术是指将包含不同种类、不同粒径、不同形貌的无机纳米材料与特殊粘接材料进行杂化复合制成的透明或半透明液体,采用适当工艺或装备在各种物质表面进行化学组装,形成均匀、稳定、牢固的转化膜或透明涂层。膜层的厚度一般处于纳微米量级,具有疏水、疏油(或亲水、亲     

关于加强基层河道管理单位人才队伍建设的思考

基层河道管理单位大多处于偏远乡村,条件艰苦、人员力量薄弱、职工队伍不稳定等问题严重制约了基层水管单位各项工作的健康、顺利开展。对此,基层河道管理单位应从建立人才开发规划、制订特殊的政策、制度、加大资金扶持力度和加强职工培训与教育等方面采取有针对性的措施或解决办法。     

751-GW分光光度计特殊故障的处理

笔者在检修 75 1—ＧＷ紫外可见光分光光度计时 ,两次遇到比较少见的特殊故障。当检查或检修好仪器各部分后 ,仪器工作均已正常 ,仪器各组稳压电源均在正常范围内 ,且用数字万用电表检查也均非常稳定 ,但在关闭光门 ,调透射比 0 %或打开光门调透射比 10 0 %时 ,均不能稳定工作     

食品安全国家标准预包装特殊膳食用食品标签

<正>1范围本标准适用于预包装特殊膳食用食品的标签(含营养标签)。2术语和定义GB 7718中规定的以及下列术语和定义适用于本标准。2.1特殊膳食用食品为满足特殊的身体或生理状况和(或)满足疾病、紊乱等状态下的特殊膳食需求,专门加工或配方的食品。     

继电保护装置干扰防护若干措施

高压变电站、发电厂是具有高强度电磁场环境的特殊区域,容易对继电保护装置造成干扰,使保护误动或拒动,危及系统安全稳定运行。为此,介绍了现阶段广东省所采取的若干抗干扰措施,并对这些措施的原理及实现方法进了简单的阐述。     

提高电视自动装置自动测量尺寸精度的一种方法

用电视方法自动测量尺寸,是测量物体图像边缘产生的信号脉冲间的时间间隔,或计算光学方法或电学方法产生的标记脉冲的物体图像的长度。如果标记脉冲是用文献(1)和(2)中所介绍的电学方法产生(由行同步脉冲同步的特殊的高稳定的高频发生器产生),那么,     

特殊浸润性纳米纤维膜材料在油水分离中的研究进展

油水混合物经过分离后再处理,不仅可以实现油、水资源的重复利用,还能有效避免由于直接排放所造成的环境污染问题,因此研究用于分离油水混合物的材料对于节约资源和保护环境就显得尤为重要.其中,特殊浸润性纳米纤维膜材料具有超疏水/超亲油或超亲水/超疏油等特性,这使其在油水分离的应用研究中得到广泛关注.基于此,本文对特殊浸润性纳米纤维膜材料在油水分离领域的研究现状和应用进行了综述.介绍了特殊浸润性材料的基础理论和电纺纳米纤维膜的应用,归纳并总结了特殊浸润性纳米纤维膜材料在油水分离领域中的研究进展,最后指出在油水分离过程中,特殊浸润性纳米纤维膜上精细的微观结构很容易受到机械损坏和化学污染,这极大地限制了其在油水分离中的应用,同时对于研究出结构稳定、耐酸碱、并且可大规模生产的高效分离性能的特殊浸润性纳米纤维膜材料进行了展望.     

新型自毁塑料

瑞典贝兰德(Belland)公司发明了一种可以用特殊化学试剂的水溶液溶解的新型塑料。新塑料能生产各种形式的塑料制品:注塑制品、型材、泡沫制品、液体塑料或刚性塑料。新塑料的特点是在水中稳定,使用寿命长,可用作能经受阳光、水和微生物作用的     

The impact of biotechnology on corporate law and regulation

The author describes how biotechnology relates to traditional corporate law and regulation, using as a basis public perceptions that this technology involves special hazards and has revolutionary implications. He notes not only the public feelings of environmental hazards, but also the moral and ethical issues. After examining the present regulatory framework, the author describes how public policy has developed in this perceived revolutionary area, as compared with the experience of nuclear power, and concludes by noting the substantial future impacts biotechnology might pose for the law.     

A critical view of severity classification in risk assessment methods

The knowledge of operational experts plays a fundamental role in performing safety assessments in safety critical organizations. The complexity and socio-technical nature of such systems produce hazardous situations which require a thorough understanding of concrete operational scenarios and cannot be anticipated by simply analysing single failures of specific functions. This paper addresses some limitations regarding state-of-the-art safety assessment techniques, with special reference to the adoption of “chain of event” models in accident causation (widely criticised by many authors), to the use of severity classes and to the adoption of the worst credible effect criterion. Such methods tend to assume a linear link between single hazards considered in isolation and corresponding consequences for safety, thus neglecting the intrinsic complexity of the systems under analysis and reducing the opportunities for an effective involvement of operational experts. An alternative approach is proposed to overcome these limitations, by distinguishing different typologies of hazards and integrating the analysis of single functions with the study of concrete operational scenarios.     

The Risk Line: a special telephone line to provide means of reporting potential dangers and to increase public participation

Injuries constitute a significant public health problem. There is a risk of injury in any environment in which persons are present. The purpose of this paper is to describe the development and experiences from the Risk Line. The Risk Line is a special telephone number to provide means of reporting potential risks for injuries and dangerous products and to increase public participation in injury reporting. Various strategies have been used to make the Risk Line well known in the population. Weekly reports on the risk of playground, traffic, recreational, and residential injuries and dangerous products have been distributed to those who are responsible for eliminating these hazards. The major risk environments reported were traffic, recreational, residential environments, and playgrounds. Seventy-seven percent of the reported hazards had been eliminated. A majority of the public (72%) who had phoned the Risk Line stated that they had become more observant and aware of risks for injuries. In conjunction with injury statistics and safety inspections, information from the Risk Line can contribute to give an improved overall picture of where priorities are needed in safety promotion and injury prevention work.     

Remaining useful life prediction for hard failures using joint model with extended hazard

In this paper, we investigate a joint modeling method for hard failures where both degradation signals and time‐to‐event data are available. The mixed‐effects model is used to model degradation signals, and extended hazard model is used for the time‐to‐event data. The extended hazard is a general model which includes two well‐known hazard rate models, the Cox proportional hazards model and accelerated failure time model, as special cases. A two‐stage estimation approach is used to obtain model parameters, based on which remaining useful life for the in‐service unit can be predicted. The performance of the method is demonstrated through both simulation studies and a real case study.     

Some hazards are more attractive than others: Drivers of varying experience respond differently to different types of hazard

The ability to detect hazards in video clips of driving has been inconsistently linked to driving experience and skill. One potential reason for the lack of consistency is the failure to understand the structural differences between those hazards that discriminate between safe and unsafe drivers, and those that do not. The current study used a car simulator to test drivers of differing levels of experience on approach to a series of hazards that were categorized a priori according to their underlying structure. The results showed that learner drivers took longer to fixate hazards, although they were particularly likely to miss hazards that were obscured by the environment (such as a pedestrian emerging from behind a parked truck). While drivers with a moderate amount of experience were as fast as driving instructors to look at hazards, they spent the greatest amount of time looking at them. Only instructors’ ability to detect hazards early in the approach translated into differences in driving speed for certain types of hazard. The results demonstrate that drivers of varying experience respond differently to different hazards, and lay the foundations for a hazard typology.     

Semi-parametric additive risk models: Application to injury duration study

In survival analysis, the Cox model is a multiplicative model and widely used in survival analysis. However, the assumption of proportional hazards in the Cox multiplicative model is a crucial one that needs to be fulfilled for the results to be meaningful. When proportionality is a questionable assumption, an alternative but less widely used method is additive model. The additive hazards model assumes that covariates act in an additive manner on an unknown baseline hazard rate.Using the emergency department (ED) visits data, we demonstrated the additive hazards regression models and showed the differences in estimates obtained by the additive hazards models and the Cox model. In our study, the Cox model gave a higher estimate than the additive hazards model. However, both models revealed similar results with regard to covariates selected to remain in the model and the estimated survival functions based on the Cox and additive hazards models were almost identical. Since Cox and additive hazards models give different aspects of the association between risk factors and the study outcome, it seems desirable to use together to give a more comprehensive understanding of data.     

消费品说明中警示信息有效性的工效学研究(Ⅰ)——警示信息对消费者危险感受与商品危险性之间关系的影响

该研究采用问卷法，通过对３０种消费品的调查，分析了消费者对消费品说明中警示信息的阅读倾向性，消费者的危险感受、消费者安全使用商品的自信度、遵守警示信息的可能性、主观危险估计和客观危险性这几项因素之间的关系。结果表明：消费者的危险感受与阅读警示信息的倾向性、遵守警告的要求之间存在高度的一致性；且与自信度呈负相关，所以可以通过研究消费者的危险感受来研究警示信息的有效性；消费者的危险感受、主观危险估计常与商品的客观危险性不一致，所以必须采取一些措施来矫正消费者的危险感受，以确保警示信息发挥应有的安全保障作用     

施工现场安全危险源实时监控与安全风险预测方法研究

对国内外建筑业施工现场安全风险的研究进行了文献综述,针对目前研究的不足之处,提出了施工现场安全危险源实时监控和安全风险实时预测的示意性模型,并详细解释了该模型的含义和方法。研究将提供一种基于前馈信号的施工现场安全危险源实时监控和安全风险实时预测的方法;并通过将现有研究的视角引入到施工现场关键安全危险源的前馈信号上,为进一步的研究打下良好的理论基础。     

Recognition of home injury risks by novice parents of toddlers

Objective

Unintentional injury in the home is a leading cause of death for toddlers. The majority of injuries occur at home; parents play a significant role in injury prevention. Health-related behavior change theory suggests that behavior change is only possible if individuals (a) recognize the problem, and (b) believe they are vulnerable. This study examined these characteristics among novice parents of toddlers by investigating how well parents recognize hazards in the home and whether they believe their toddlers are vulnerable to those hazards.

Methods

Three types of participants were recruited: novice parents of toddlers ages 12-36 months, daycare employees, and pediatric healthcare workers. All participants were examined three rooms simulating a typical toddler's bedroom, a living room, and a bathroom. Participants marked any hazards they recognized with stickers. Parents completed the hazard identification task twice, once identifying hazards for all toddlers and another time identifying hazards for their child.

Results

Participants identified less than half the hazards present in the simulated rooms; parents identified more hazards than comparison groups. Parents identified significantly fewer hazards for their own child than they identified for other children.

Discussion

Although parents identified more hazards than the professionals, they failed to identify a large portion of hazards and they perceived their own children to have less vulnerability than toddlers more broadly. Results indicate that education about toddler's vulnerability to injury in the home, as well as instructing parents about what situations are hazardous, might be considered during development of toddler home injury prevention programs.     

室内LED射灯光生物安全分析

针对LED射灯在室内环境下的潜在光生物安全风险,通过模拟室内LED射灯的实际照明,分别测量了定距离不同功率和等功率不同距离下LED射灯的蓝光危害值(LB)及辐照度.根据GB/T20145—2006《灯和灯系统的光生物安全》的要求,对LED射灯的光生物安全性进行了评价.结果表明,在定距离1.0m的室内使用情况下,实测功率4W以上的LED射灯,其蓝光危害值都超过了安全阈值100W·m-2·sr-1,存在不同程度的视网膜蓝光危害,危害程度与灯功率和辐照时间呈线性相关.LED射灯的辐照度伤害与蓝光危害有着相似的规律.在一般室内(辐照距离一定)情况下,LED射灯的功率是影响视网膜蓝光危害和辐照度危害的主要因素,随着灯功率增大,危害程度也随之增大.在特殊室内环境下(辐照距离不定),辐照距离也是影响视网膜蓝光危害和辐照度危害的重要因素.