车载精密光电设备平顺性试验研究

对某车载光电探测设备进行了平顺性试验研究。根据该光电设备的结构特点和性能要求,在旋转机座、俯仰转台和红外望远镜上选取3个测点,经试验得到了这3个测点在不同路况、不同车速情况下的加速度数据。通过对试验数据的整理,得出光电探测仪不同部位及整机的振动强度随车速变化曲线,为车载光电平台的减、隔振设计提供参考。     

First-trimester diagnosis of hydrolethalus syndrome in a Chinese family

We report a case resembling hydrolethalus syndrome in a Chinese family. Fetal polydactyly, syndactyly, encephalocele and cardiac malformation were detected on ultrasound examination at 12 weeks' gestation. Termination of pregnancy was performed, and postmortem examination confirmed the findings. This is the first report of a first-trimester prenatal diagnosis of hydrolethalus syndrome in the Chinese population. Copyright © 2004 John Wiley & Sons, Ltd.     

Cross-cultural comparison of concrete recycling decision-making and implementation in construction industry

Waste management is pressing very hard with alarming signals in construction industry. Concrete waste constituents major proportions of construction and demolition waste of 81% in Australia. To minimize concrete waste generated from construction activities, recycling concrete waste is one of the best methods to conserve the environment. This paper investigates concrete recycling implementation in construction. Japan is a leading country in recycling concrete waste, which has been implementing 98% recycling and using it for structural concrete applications. Hong Kong is developing concrete recycling programs for high-grade applications. Australia is making relatively slow progress in implementing concrete recycling in construction. Therefore, empirical studies in Australia, Hong Kong, and Japan were selected in this paper. A questionnaire survey and structured interviews were conducted. Power spectrum was used for analysis. It was found that “increasing overall business competitiveness and strategic business opportunities” was considered as the major benefit for concrete recycling from Hong Kong and Japanese respondents, while “rising concrete recycling awareness such as selecting suitable resources, techniques and training and compliance with regulations” was considered as the major benefit from Australian respondents. However, “lack of clients’ support”, “increase in management cost” and “increase in documentation workload, such as working documents, procedures and tools” were the major difficulties encountered from Australian, Hong Kong, and Japanese respondents, respectively. To improve the existing implementation, “inclusion of concrete recycling evaluation in tender appraisal” and “defining clear legal evaluation of concrete recycling” were major recommendations for Australian and Hong Kong, and Japanese respondents, respectively.     

The relationship between demographic/educational parameters and perceptions,knowledge and earthquake mitigation in Israel

Perceptions, knowledge and mitigation are factors that might play a role in preventing injury and loss of life during a major earthquake.² Little is known about the relationships between different demographic and educational parameters and these factors. A national representative sample of 495 adults was investigated in order to determine the relationship between demographic and educational parameters in terms of the perceived threat, perceived coping, knowledge and mitigation of earthquakes in Israel. Compared to females, males perceived the threat of earthquakes to be lower (t=3.183, p=0.002), manifested higher levels of perceived coping (t=2.55, p=0.011), and had higher levels of earthquake related knowledge (t=2.047, p=0.041). We conclude that there are gender differences in perceptions and knowledge regarding earthquakes.     

Improving situational awareness through the design of offshore installations

Maintaining the situational awareness of control room operators on offshore installations contributes to the timely diagnosis of conditions and making appropriate decisions. This is particularly important when dealing with events and incidents. Recent initiatives aimed at reducing operators’ exposure to the hazards of working on offshore installations may have a negative impact upon situational awareness within the control room environment.This paper discusses mitigation of the negative impact through the design and operation of the installation and control system; either by improving the general level of situational awareness or by specifically targeting the areas affected by these initiatives.