洪涝灾后铁路抢修现场蚊蝇防治效果研究

目的探讨洪涝灾后铁路抢修现场蚊蝇防治的有效方法。方法每天防治一次,直至蚊蝇密度下降率到70%时,改隔日一次。结果 连续处理5 d后,蚊虫密度下降率为85.39%～100%,蝇密度下降率为70.34%～100%。有效地控制了蚊蝇密度。结论铁路抢修现场病媒生物防治应同环境治理工作同步进行,以垃圾站及厕所作为防治重点。     

铁路沿线伙食团卫生状况调查

为掌握铁路沿线伙食团卫生状况,对340个伙食团卫生情况进行调查,存在卫生管理组织制度不落实;从业人员未体检办证、无工作服;建筑与布局不合理;卫生设施设备不齐全;食品采购不索证索票、购买不安全食品;食品贮存不符号要求和食品加工过程有交叉污染等7个方面问题。应采取对策、科学管理,确保铁路沿线伙食团食品安全和一线职工身体健康。     

Contact dermatitis and its relationship to atopy in workers on the Polish State Railways

Clinical examinations, patch tests and prick tests were carried out in a group of railwaymen. Only 3 had both eczema and atopy. Prick tests were positive in a high proportion of subjects, including both those with eczema and controls.     

Modeling the Depth of Surface Cracks in Brake Disc

The article presents the state of knowledge and research in the field of surface cracks occurring in disc braking systems of rail and car vehicles. The craze formed during the operation of vehicles is particularly dangerous and leads to breaking the disc into several pieces. It may lead to a loss of braking force and damage to the entire disc brake caliper. The main aim of the research is to identify surface cracks in brake discs made of cast iron and use experimental methods to estimate their depth. Research were conducted on the disc braking system developed by the authors. In examining the location and depth of cracks, the penetration method, ultrasound, as well as a special probe were used. This device measures the crack depth based on the electrical resistance between two points on the surface of the metallic object. The tests showed that the first microcracks on the brake discs appeared after 309 braking tests on the test stand. In addition, it was observed that the surface cracks length of the disc increased linearly to depth until they reached about 11.5–12 mm with corresponded to crack lengths in the range of 65–70 mm. However, determination of the regression functions presented in the article allows to estimate the depth of surface cracks up to 70 mm long on cast iron brake discs by measuring their length.     

铁路工伤危险因素的控制及评价

[目的]预防和控制铁路运输工伤事故。[方法]运用流行病学调查方法和SPSS FOR WINDOWS 12．0软件，分析工伤事故发生原因，建立事前预防控制体系并在试点区实施干预。[结果]铁路运输工伤事故发生率为23．68／10万，违章操作是其主要原因（61．3％）。文化程度较低、工龄较短、吸烟、安全意识不强、违规操作、机器异常均可使职业伤害发生的危险性增高。实施干预后工伤事故发生率有所下降。[结论]工伤是可以预防和控制的。只要领导重视，以人为本，采取有效的工伤事故预防控制体系，完全可以减少工伤事故发生率，从而达到保护职工健康、推动运输经济可持续发展的目的。     

青藏高原喜马拉雅旱獭疫源地鼠疫菌质粒种类及特性的研究

用琼脂糖凝胶电泳的方法，研究了青藏高原喜马拉旱獭鼠疫自然疫源地的９１４株鼠疫菌，共观察到１０种质粒，其中大质粒分子量差异较大，为我国各疫源地中鼠疫菌所含大质粒最独特的地区，其分布特征是：含５２×１０＾５质粒的菌株分布在祁连山南、北木刻级青海湖的环湖地区；带６５×１０＾６闰的菌，主要见于青南高原。当金山口甘南山地、冈底斯山与喜马拉雅山之间和藏南谷地以及新疆南部亦有零星分布。鉴于我国青藏高原喜马拉雅旱     

青藏高原藏药濒危现状及其资源保护策略

随着藏药产业快速发展,对高原药用植物濒危状况的研究不足,保护措施乏力以及高原生态环境固有的脆弱性等因素,造成藏药资源短缺,影响了藏药产业的可持续发展。如何根据已有的藏药资源濒危信息,制定出切实可行的保护计划,是藏药资源合理开发利用亟待解决的问题。为了初步摸清青藏高原濒危藏药的家底,使用《中国珍稀濒危植物》的等级划分方法,整理出青藏高原濒危藏药物种名录,分为一级(濒危)11种、二级(稀有)21种和三级(渐危)42种,共74种。其中除《中国珍稀濒危植物》等国家保护名录收录的,还包括建议增加的青藏高原五省(区)藏区濒危藏药物种。同时结合藏药资源濒危现状,探讨了从定期进行濒危藏药物种的调查、建立濒危藏药的种质资源库、就地保护、人工种植研究和更新观念,合理开发利用五个方面开展工作的保护策略,以期为青藏高原藏药资源保护和可持续发展利用提供科学依据。     

A Numerical Study on Structural Performance of Railway Sleepers Using Ultra High-Performance Concrete (UHPC)

This numerical study investigates the structural performance of railway sleepers made of ultra high-performance concrete (UHPC). First, numerical concrete sleepers are developed, and the tensile stress-strain relationship obtained from the direct tension test on the UHPC coupons is used for the tensile constitutive model after applying a fiber orientation reduction factor. The numerical sleeper models are validated with the experimental data in terms of the force and crack-width relationship. Second, using the developed models, a parametric study is performed to investigate the performance of the UHPC sleepers while considering various design/mechanical/geometrical parameters: steel fiber contents, size of the cross-section, and diameter and strength of prestressing (PS) tendons. The simulation results indicate that the size of the cross-section has the most impacts on the performance, while the effect of yielding strengths of PS tendons is minimal among all the parameters. Engineers need to pay attention to efficiency and an economical factor when using a larger cross-section, since sleepers with larger cross-sections can be an over-designed sleeper. This study suggests an economical design factor for engineers to evaluate what combination of parameters would be economical designs.     

青藏铁路沿线喜玛拉雅旱獭生态学研究

目的研究青藏铁路沿线鼠疫宿主动物喜玛拉雅旱獭生态学规律的,为预防控制鼠疫提供评价依据。方法对喜玛拉雅旱獭野外栖息环境、活动规律、洞巢的结构、食性生态指标进行现场观察和实验室分析和研究。结果旱獭为家族式群栖动物,营昼间活动 活动范围随旱獭个体、季节不同而异,6月活动范围广,9月活动范围小,雄性大于雌性,成体大于幼体。食物以羊胡草、苔草、紫花针茅等植物为主,繁殖期4～6月,平均子宫瘢5.3个,平均胎数3～7只,总体性别比接近1：1。依据臼齿面磨损程度、体长、体重等特征划分年龄组,即1～9龄,种群年龄组为金字塔型。结论喜玛拉雅旱獭主要栖息在海拨3 000～5 460 m之间的高原草原、高山草甸、谷地灌丛草甸草原,喜玛拉雅旱獭属松鼠科旱獭属,在青藏铁路沿线区域属优势种群,其生态学特点与鼠疫在动物间的流行存在紧密关联,具有重要的流行病学价值。     

Persistent Post‐Traumatic Headache,Postconcussion Syndrome,and Whiplash Injuries: The Evidence for a Non‐Traumatic Basis With an Historical Review

There has been intense controversy about postconcussion syndrome since Erichsen's publication in 1866 on railway brain and railway spine. The fascinating history of this debate will be reviewed and then the non‐organic explanations for postconcussion syndrome, headaches after head injury, and chronic whiplash injuries and headaches will be explored including the following: psychogenic, psychosocial, sociocultural, base rate misattribution, chronic pain, compensation and litigation, and malingering.