单词:quasi-parabolic reflector
单词:quasi-parabolic reflector 相关文章
By Jill Moss Broadcast: July 28, 2003 This is Bill White with the VOA Special English Development Report. Millions of people around the world cook their food over a smoky fire every day. It is often d
by Jason Marshall Weve now talked about three methods for calculating average values: the mean, median, and mode (affectionately known as the three Ms). So, are we done? Is that everything we could ever want to know about interpreting average values?
In 1970, the Soviet Union put a laser reflector on the moon, carried by a rover. A few months later, it disappeared. Some speculated that the rover had fallen into a crater or parked in such a way as to render the reflector inaccessible. Now after 40
据《科学》杂志报道,苏联的月球车40年前在月球表面留下了激光反射器,虽然经过多年的搜寻科学家始终没有发现激光反射器的踪迹。 4月22日,一组物理学家终于发现了来自反射器的微弱闪
Gain - This is an increase in signal power, due to a boost from an electronic device. Garbage - These are unwanted characters that appear because of either incorrect settings or noise. Gate - These ar
This is Scientific American's 60-Second Science. I'm Steve Mirsky. Got a minute? The 2011 Nobel Prize in chemistry goes to Daniel Schechtman of the TechnionIsrael Institute of Technology in Haifa. Schechtman discovered what are called quasicrystals.
This is the VOA Special English Development Report. Millions of people around the world cook their food over a smoky fire every day. It is often difficult to find wood for the fire. People who do not have wood must spend large amounts of money on co
By Greg Flakus Albuquerque, New Mexico 25 July 2007 Large scale collection of solar power arrays As the world searches for ways to produce energy without burning fossil fuel, there is increased interest in solar energy. One place associated with sola
DEVELOPMENT REPORT – May 13, 2002: Solar Cookers By Jill Moss This is the VOA Special English Development Report. Millions of people around the world cook their food over a smoky fire every day. It
The Five-hundred-meter wide Aperture Spherical Telescope, or FAST, is now operational in the mountains of Guizhou in southwest China. FAST has been designed to help Chinese researchers better understand our universe, as well as probe the cosmos for e
Bart's upstairs neighbor was driving him nuts. He made all kinds of strange noises at all kinds of strange hours. If I tell my neighbor he's noisy, he won't believe me, Bart thought. He'll believe me only if he lives downstairs and hears himself upst
By Paul Sisco Washington 14 November 2007 At the McDonald Observatory in western Texas, a unique space program has been quietly underway for more than 30 years. It is called the Lunar Laser Ranging Program. VOA's Paul Sisco has more. Research scienti
The construction of the project was started in 2011 with an investment of 1.2-billion yuan, or about 180 million US dollars. The 500 metre Aperture Spherical Telescope, or FAST, is the size of 30 football fields. It's located in a hollow that was for