问题 问答题 简答题

何谓锅炉排污?有几种排污?各有何作用?

答案

参考答案:

从锅炉水中排除浓缩的溶解固体物和水面上的悬浮固体物的操作叫排污。

排污有两种,即连续排污和间断排污。

连续排污的集水管设在汽包的汽水界面以下约80mm处,此处正好是蒸汽释放区,是炉水中盐浓度最大的地方,从这里连续排出部分炉水以维持炉水含盐量和蒸汽含盐量在规定范围内。连续排污也叫表面排污。

间断排污口设在锅炉的最低点,那里是溶解固体物和沉淀物堆积的地方,间断排污的目的是排除炉内沉淀物和部分含溶解固体物质浓度较高的炉水,以保持炉水水质合格。间断排污也叫定期排污。

单项选择题

Any normal species would be delighted at the prospect of cloning. No more nasty surprises like sickle cell or Down syndrome--just batch after batch of high-grade and, genetically speaking, immortal offspring! But representatives of the human species are responding as if someone had proposed adding Satanism to the grade-school Curriculum. Suddenly, perfectly secular folks are throwing around words like sanctity and retrieving medieval-era arguments against the pride of science. No one has proposed burning him at the stake, but the poor fellow who induced a human embryo to double itself has virtually recanted proclaiming his reverence for human life in a voice, this magazine reported," choking with emotion."

There is an element of hypocrisy to much of the anti-cloning furor, or if not hypocrisy, superstition. The fact is we are already well down the path leading to genetic manipulation of the creepiest sort. Life-forms can be patented, which means they can be bought and sold and potentially traded on the commodities markets. Human embryos are life-forms, and there is nothing to stop anyone from marketing them now, on the same shelf with the Cabbage Patch dolls.

In fact, any culture that encourages in vitro fertilization has no right to complain about a market in embryos. The assumption behind the in vitro industry is that some people’s genetic material is worth more than others’ and deserves to be reproduced at any expense. Millions of low-income babies die every year from preventable ills like dysentery, while heroic efforts go into maintaining yuppie zygotes in test tubes at the unicellular stage. This is the dread "nightmare” of eugenics in familiar, marketplace form which involves breeding the best-paid instead of the best. Cloning technology is an almost inevitable byproduct of in vitro fertilization. Once you decide to go to the trouble of in vitro, with its potentially hazardous megadoses of hormones for the female partner and various indignities for the male, you might as well make a few backup copies of any viable embryo that’s produced. And once you’ve got the backup organ copies, why not keep a few in the freezer, in case Junior ever needs a new kidney or cornea

The critics of cloning say we should know what we’re getting into, with all its Orwellian implications. But if we decide to outlaw cloning, we should understand the implications of that. We would be saying in effect that we prefer to leave genetic destiny to the crap shooting of nature, despite sickle-cell anemia and Tay-Sachs and all the rest, because ultimately we don’t trust the market to regulate life itself. And this may be the hardest thing of all to acknowledge: that it isn’t so much 21st century technology we fear, as what will happen to that technology in the hands of old-fashioned 20th century capitalism.

We can learned from the text that cloning techniques would be applied to()

A.family planning

B. marketing strategies

C. preventable diseases

D. organ replacements

单项选择题