问题 问答题 简答题

太空太阳能电站的优点是什么?

答案

参考答案:

在太空和月球建造太阳能发电站,有许多无可比拟的优点。首先,地面一天24小时约一半时间为夜晚,无法发电,多云以及阴雨天气也不适合发电。位于静止轨道上的太空太阳能电站,除了一年两次的食蚀之外,几乎24小时均能发电。此外,静止轨道上太阳能的强度是地面的2倍,日照时间是地面的4-5倍,发电能力更是地面的8-10倍。太阳能取之不尽用之不竭,免费使用,既不需要类似火力发电那样的石油以及煤炭等资源,也不会排放导致地球变暖的二氧化碳,是一种可无限获得的洁净能源。

美国设计了一种被称为“标准模式”的太空太阳能电站,重约5万吨,太阳能电池板面积为10千米×5千米,通过长约1千米的输电天线,利用2.45千兆赫兹微波向地面无线传送电力。地面上,由大小为10千米×13千米的接收天线系统接收电力。

要在太空建造太阳能电站,并解决电力传输问题,科学家要走的路还很长。

单项选择题

It is not just Indian software and "business-process outsourcing" firms that are benefiting from the rise of the internet. Indian modern art is also on an upward spiral, driven by the aspirations of newly rich Indians, especially those living abroad, who use the internet to spot paintings and track prices at hundreds of gallery and auction websites. Prices have risen around 20-fold since 2000, particularly for prized names such as Tyeb Mehta and F. N. Souza.

There would have been "no chance" of that happening so fast without the internet, says Arun Vadehra, who runs a gallery in Delhi and is an adviser to Christie’s, an international auction house. He expects worldwide sales of Indian art, worth $200million last year, to double in 2006. It is still a tiny fraction of the $ 30 billion global art market, but is sizeable for an emerging market.

For newly rich often very rich-non-resident Indians, expensive art is a badge of success in a foreign land. "Who you are, and what you have, are on your walls," says Lavesh Jagasia, an art dealer in Mumbai. Indian art may also beat other forms of investment. A painting by Mr. Mehta that fetched $1.58million last September would have gone for little more than $100,000 just four years ago. And a $22million art-investment fund launched in July by Osian’s, a big Indian auction house, has grown by 4.1& in its first two months.

Scant attention was paid to modern Indian art until the end of the 1990s. Then wealthy Indians, particularly those living abroad, began to take an interest. Dinesh Vazirani, who runs Saffronart, a leading Indian auction site, says 60% of his sales go to buyers overseas.

The focus now is on six auctions this month. Two took place in India last week; work by younger artists such as Surendran Nair and Shibu Natesan beat estimates by more than 70%. Sotheby’s and Christie’s have auctions in New York next week, each with a Tyeb Mehta that is expected to fetch more than $1 million. The real question is tee fate of other works, including some by Mr. Souza with estimates of up to $600,000. If they do well, it will demonstrate that there is p demand and will pull up prices across the board. This looks like a market with a long way to run.

It can be inferred from the second paragraph that the recent rapid development of Indian modern art is closely associated with ()

A. economic boom

B. real estate

C. electronic element

D. international action

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