电梯轿厢上行超速保护装置现状分析与检验要求

曳引驱动电梯上应装设符合要求的轿厢上行超速保护装置,使轿厢制停或使轿厢速度降低至对重缓冲器能够承受的设计范围内,防止“冲顶”事故。本文阐述了上行超速保护装置的设置历程,概述了上行超速保护装置的构成及现状,分析失效原因,提出检验方法。在此基础上指出检验过程中面临的问题,认为缺乏统一定性定量的试验方法及判别标准是目前亟待解决的问题关键,提出了相应的改善建议。     

新冠肺炎疫情期间铁路客运职工心理影响调查

选取某铁路局集团公司客运系统人员为研究对象,调查新型冠状病毒肺炎疫情对铁路客运职工的心理影响情况,以调查问卷的方式收集社会人口学数据、工作情况、疫情认知和行为改变、广泛性焦虑自评量表(GAD-7)、患者健康问卷抑郁量表(PHQ-9)、事件影响量表修订版(IES-R)。采用单因素和多重线性回归分析其影响因素,结果显示,客运人员PHQ-9评分为6.34±6.730分,GAD-7评分为4.68±5.462分,IES-R评分为20.57±19.140分;多重线性回归结果表明年龄、夜班频率、焦虑、抑郁为IES-R总分的影响因素。客运人员有轻度的焦虑、抑郁;年龄、夜班频率、焦虑、抑郁均会加大客运系统人员对新冠肺炎疫情的应激反应程度;相关部门应关注职工心理健康状况,改善焦虑和抑郁状态。     

铁路货车制造企业焊接烟尘治理探讨

为改善焊接作业环境、保护职工健康,基于某铁路货车企业的生产工艺和焊接烟尘治理难点,从完善焊接烟尘治理技术方案、优化焊接方法和焊接结构、改造厂房加强换气通风等方面总结治理措施,提出了焊接烟尘综合治理的新方向,即融入绿色设计思维、提高工艺制造水平、结合智能制造和采取综合治理方案。     

基于改进型AES算法汽车门禁系统的研究

汽车门禁系统已成为汽车智能与安全领域的重要一部分.车主手持智能钥匙靠近汽车,通过车载基站与钥匙的双频通信,实现车门的开与关,还可实现发动机的一键启动.同时,对信号加密采用了改进的AES算法,加入了循环扩展密钥,加大了密码的破解难度.并对整个系统进行了建模仿真,分析了信号传输的误码率.图6,表1,参5.     

人车碰撞中行人大腿保护研究

研究提高人车碰撞中行人大腿的保护性能的方法。首先对大腿伤害机理,伤害评价指标以及车辆自身结构进行阐述和研究,总结车辆前端结构的关键参数;对某车型的前大灯进行结构改进,按照欧洲新车安全评鉴协会(Euro NCAP)行人大腿保护的试验评价方法,改进后进行碰撞试验;建立装有发动机罩安全气囊的整车仿真模型,验证安全气囊对行人大腿的保护性能。经过试验和仿真可以得出:车辆前大灯结构刚度改进和发动机罩安全气囊可以改善行人大腿的保护性能。     

混铁车强制冷却场集尘系统改造

混铁车强制冷却场原设计为露天敞开式,有4个工作台位,在强制冷却(采用大风量风机经过特制送风头送入炉膛内,将其温度从350℃左右冷却到40℃)过程中,产生了大量扬尘,不仅污染了周围环境,还严重威胁了岗位职工的身体健康.     

流域开发项目环评的深层思考

通过对一西部流域梯级开发水电站环评及其显现的环境问题案例,产生对流域梯级开发项目进行分割式单项环评存在问题的思考,提出对梯级开发环境影响评价必须贯穿流域规划,建立累积环境影响的基本概念和理论,并从其管理机制及公众参与机制上保证流域开发环评的有效实施,使环评在流域梯级开发中真正发挥对生态环境调控的作用.     

State-level seat belt use in the United States, 2011–2016: Comparison of self-reported with observed use and use by fatally injured occupants

Introduction: Despite 49 states and the District of Columbia having seat belt laws that permit either primary or secondary enforcement, nearly half of persons who die in passenger vehicle crashes in the United States are unbelted. Monitoring seat belt use is important for measuring the effectiveness of strategies to increase belt use. Objective: Document self-reported seat belt use by state seat belt enforcement type and compare 2016 self-reported belt use with observed use and use among passenger vehicle occupant (PVO) fatalities. Methods: We analyzed the Behavioral Risk Factor Surveillance System (BRFSS) self-reported seat belt use data during 2011–2016. The Pearson correlation coefficient (r) was used to compare the 2016 BRFSS state estimates with observed seat belt use from state-based surveys and with unrestrained PVO fatalities from the Fatality Analysis Reporting System. Results: During 2011–2016, national self-reported seat belt use ranged from 86–88%. In 2016, national self-reported use (87%) lagged observed use (90%) by 3 percentage points. By state, the 2016 self-reported use ranged from 64% in South Dakota to 93% in California, Hawaii, and Oregon. Seat belt use averaged 7 percentage points higher in primary enforcement states (89%) than in secondary states (82%). Self-reported state estimates were strongly positively correlated with state observational estimates (r = 0.80) and strongly negatively correlated with the proportion of unrestrained PVO fatalities (r = −0.77). Conclusion: National self-reported seat belt use remained essentially stable during 2011–2016 at around 87%, but large variations existed across states. Practical Applications: If seat belt use in secondary enforcement states matched use in primary enforcement states for 2016, an additional 3.98 million adults would have been belted. Renewed attention to increasing seat belt use will be needed to reduce motor-vehicle fatalities. Self-reported and observational seat belt data complement one another and can aid in designing targeted and multifaceted interventions.     

2 ,4-二硝基苯肼固相吸附/高效液相色谱法测定车内空气中醛酮类物质

建立了2,4-二硝基苯肼固相吸附／高效液相色谱同时测定车内空气中4种醛酮类物质的方法,研究了固相吸附采样和前处理方法,优化了试验条件。4种醛酮类物质在一定质量范围内工作曲线线性良好,甲醛、乙醛、丙烯醛、丙酮的检出限分别为0．075μg／m^3、0．207μg／m^3、0．715μg／m^3、0．159μg／m^3（按采样体积12L计）,实际样品测定的RSD为7.5％-9．7％。     

European regulations to reduce lead emissions from automobiles – did they have an economic impact on the German gasoline and automobile markets?

Environmental protection policies in the automobile market were not implemented until the motorisation of the masses in the 1960s caused an increasing environmental burden. The rising air pollution was considered a latent danger to humans, animals and plants. In the years up to 1985 the EU passed several regulations to limit the mass pollutants CO, CxHy and NOx. Germany was the first EU-member nation to also be concerned with lead in gasoline, passing reduction regulations as early as 1971. In 1986, several EU-member nations implemented the supply of unleaded gasoline. This decision was predominantly based on information about widespread forest damage. The reduction of lead emissions due to these regulations could be verified in different environmental systems. An example of this was the decline of atmospheric lead concentrations and human blood lead levels in Germany. With regard to industries, the German mineral oil and automobile markets were affected mostly. The price trend of gasoline was no longer only influenced by varying crude oil prices but also by tax discrimination between leaded and unleaded fuel. With regard to the distribution system, the market positions particularly of the medium-sized traders and the independent importers were weakened. In the automobile market, favourable terms of competition were experienced by producers who had already gained experience with catalyst systems in the US market. The Gasoline Lead Content Regulations had no significant effects on further economic indicators, except for competition. Electronic Publication