摘要：TFL开发了一种设计简单,耐用的新型铷原子频标。这个设计在传统的设计上进行了两项改进: ·采用适当的电路措施改进震动和加速度的频率灵敏度

摘要：Ambient air pollution in China has worsened following dramatic increases in industrialization, automobile use and energy consumption. Particularly bothersome is the increase in the PM2.5 fraction of pollutants. This fraction has been associated with increasing rates of cardio-respiratory disease in China and elsewhere. Ambient pollutant levels have been described in many of China＇s cities and are comparable to previous levels in southern California. Lung cancer mortality in China has increased since the 1970s and has been higher in men and in urban areas, the exact explanation for which has not been determined. The estimation of individual risk for Chinese citizens living in areas of air pollution will require further research. Occupational cohort and casecontrol designs each have unique attributes that could make them helpful to use in this setting. Other important future research considerations include detailed exposure assessment and the possible use of biomarkers as a means to better understand and manage the threat posed by air pollution in China.

摘要：随着环保观念的普及,这些曾经服务人类的大家伙,将会变成房屋、餐厅、快艇、甚至有个性的艺术品。飞机可以用来做什么？带人类翱翔。退役的飞机又可以做什么？似乎仅仅是一个毫无用处的＂大铝罐＂。

摘要：对于开关电源设计工程师,定位开关电源电路中的异常行为常常是一种挑战,而且非常浪费时间。在观察持续时间较长的信号时,手工监视波形是不实际的。此外,只有记录长度经过缩减的波形才可以进行手工监视,但分析结果却受到人为错误的影响。