什么是无缝线路的温度应力?
参考答案:如果钢轨完全被固定,不能随温度变化而自由伸缩,则在钢轨内部产生应力,这种由于钢轨温度变化而在钢轨内部产生的应力,称为温度应力。
不接地的直流均衡汇流母线涂()色漆。
A.蓝
B.绿
C.紫
D.黑
Despite (1) that alcoholic beverages may (2) , a leading medical expert is advising: don’t (3) just yet. Anybody who’s ever worked in a hospital sees the hospital is full of patients that have (4) disease, but the hospital is not full of patients that have disease related to cholesterol and (5) . In an (6) in the current New England Journal of Medicine, Dr. Goldberg of Columbia University said it is time to see (7) prevents heart disease. Such a study would give (8) to one group of heart disease patients and not to another, and see (9) . In the latest study, which followed (10) over a 12-year period, researchers found that those who drank (11) drinks per week (12) of heart attack by (13) compared to (14) . The lead author, (15) Kenneth Mukamal of Beth Israel Deaconess Medical Center in Boston, insists his study is (16) . For one thing, other studies have not looked at (17) . Dr. Mukamal says (18) also appear to settle which alcoholic beverage are (19) . "Beer and spirits, beer and liquor, were most ply (20) ."