Defining Dry Eye from a Clinical Perspective

Over the past decades, the number of patients with dry eye disease (DED) has increased dramatically. The incidence of DED is higher in Asia than in Europe and North America, suggesting the involvement of cultural or racial factors in DED etiology. Although many definitions of DED have been used, discrepancies exist between the various definitions of dry eye disease (DED) used across the globe. This article presents a clinical consensus on the definition of DED, as formulated in four meetings with global DED experts. The proposed new definition is as follows: “Dry eye is a multifactorial disease characterized by a persistently unstable and/or deficient tear film (TF) causing discomfort and/or visual impairment, accompanied by variable degrees of ocular surface epitheliopathy, inflammation and neurosensory abnormalities.” The key criteria for the diagnosis of DED are unstable TF, inflammation, ocular discomfort and visual impairment. This definition also recommends the assessment of ocular surface epitheliopathy and neurosensory abnormalities in each patient with suspected DED. It is easily applicable in clinical practice and should help practitioners diagnose DED consistently. This consensus definition of DED should also help to guide research and clinical trials that, to date, have been hampered by the lack of an established surrogate endpoint.     

Driver detection and recognition of lineside signals and signs at different approach speeds

A study was carried out using simulation to investigate driver responses to lineside signals and signs at various approach speeds. The objectives of the study were: (1) to find out whether train speed would significantly affect signal/sign reading; (2) to examine at which point certain types of signs or signals could be detected or recognised, and (3) to determine a speed cut-off level above which certain types of signs or signals are no longer recognisable or detectable. Fifty-seven train drivers from 12 Train Operating Companies in the UK participated in the trials. Twenty different types of lineside signs and ten types of signals were tested under six different approach speeds ranging from 100 to 350 km/h (62–218 mph). Driver performance measures were ‘time remaining to the signal/sign’ at the point of detection or recognition, and reading error rate. The results showed a significant influence of train speed on driver responses to lineside signals/signs and demonstrated a non-linear relationship between driver responses to signals/signs and approach speed. This has been used to estimate a maximum approach speed limit within which a specific signal or sign can be correctly detected or recognised. The findings and implications of the study are discussed in the paper.     

Microwave Communication to Moving Parts Inside Machines

Cables to moving parts on a linear actuator in production machines, such as pick-and-place machines, are a source of unreliability owing to the possible breaking of a cable. They further reduce the positioning precision of the actuator owing to additional forces. Slotted waveguide systems for rail vehicles based on 2.4 GHz transmission frequency are well known, but transmitters/receivers and waveguides are bulky. The paper reports on the reduction in size of the equipment, adapted to 5.8 GHz using a commercial off-the-shelf RadioLan communication module. Further, the efficient termination of the wave-guide and a new way to reduce standing-wave effects is also discussed.     

立井钢丝绳罐道的特点及使用

介绍了钢丝绳罐道的特点,从《煤矿安全规程》的要求出发,考虑钢丝绳罐道的形式、 刚度、定位张紧、布置方式、钢丝绳数目等因素,分析了钢丝绳罐道的选择要点,并指出了钢丝绳罐 道的使用和维护方法。     

基于Lab VIEW的小型汽油机磁电机点火提前角的测量

本文介绍了磁电机点火系统的点火提前角测量原理。对点火系统的点火信号和触发信号进行采集、调理，再用单片机进行处理，最后用LabVIEW进行点火提前角数据存储和显示。     

用φ76 mm穿孔机组生产φ63mm毛管的设备改进

介绍了用Φ76mm穿孔机组生产Φ63mm毛管的设备概况及其改进。改进后，Φ76mm穿孔机组增加了产品范围为后面的冷技工序减少了拉拔道次，从而降低了Φ51mm以下冷拔管的生产成本。     

聚四氢呋喃及其下游产品的开发应用

本文论述了聚四氢呋喃技术进展、氨纶弹性纤维发展现状和国内外聚四氢呋喃产能和需求。     

中国先进研究堆导流箱流场的数值模拟

采用目前国内普遍使用的计算流体力学 (CFD)软件PHOENICS 3 2对中国先进研究堆不同结构的导流箱的三维流场进行数值模拟计算。结果表明 :导流箱入口导流板和导流筒能显著改善导流箱入口冷却剂的流动状况 ,获得入口冷却剂沿周向均匀分流的效果 ,达到显著减缓入口冷却剂对垂直辐照孔道导管及安全棒导管直接的横向水力冲刷的设计目的     

海底沉积物中天然气水合物生成和分解规律研究进展

对国内外有关海底沉积物中天然气水合物生成和分解规律方面的研究进行了详细调研,得到如下结论:天然气水合物的生成和分解条件在海底沉积物中与在井筒、管道中有明显不同,其主要原因是多孔介质中流体与孔隙壁面间的界面效应对海底沉积物中天然气水合物的形成条件会产生明显影响;在海底沉积物中天然气水合物生成和分解条件的数值模拟技术研究方面,研究者大都假设以天然气水合物作为盖层的成藏类型,借助常规油气藏数值模拟技术进行模拟研究;影响海底沉积物中天然气水合物生成和分解条件的因素很多,因此海底沉积物中天然气水合物生成和分解规律研究必须借助试验模拟、数值模拟和现场测试相结合的综合方式进行。该调研成果可为今后天然气水合物经济有效开采技术方案选择和进行天然气水合物危害控制等提供参考。