Experimental modeling of a middle-rise office building via ambient modal identification is presented.

通过环境激励模态识别技术对一座中高层新结构大楼环境激励试验建模研究。

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Historians suggest that the advent of mass tourism began in England during the industrial revolution with the rise of the middle class and the availability of relatively inexpensive transportation.

历史学家认为，大众旅游的出现始于工业革命时期的英国，当时中产阶级崛起，交通费用也变得相对便宜。

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But climate change negotiators worry that without quick action, the carbon footprint of countries like India and China will rise dramatically as their fast-growing economies propel millions into the middle class.

VOA: standard.2009.11.27

The graduate without a future, then is a middle-class, mostly developed world phenomenon, separate from the rise of youth unemployment.

FORBES: Getting Younger

We still have enormous challenges because middle-class families have not seen their wages and their incomes rise for the last 20 years, even as those of us at the very top have seen an extraordinary explosion in our wealth and our incomes.

WHITEHOUSE: The White House

Meanwhile, Iran-related tensions began to rise last week in the Middle East.

ECONOMIST: Iran's president visits New York