问题 问答题 简答题

怎样检查焊缝裂纹?

答案

参考答案:

①目视法。观察焊缝及邻近漆膜状态,发现可疑处,将漆膜除净,用4~10倍放大镜观察。

②着色探伤法。将可疑处漆膜除净、打光、洗净,吹干后喷涂渗透液,隔5~10min,最长10min(时间根据光洁度和气温而定)后,用洗净液除去多余的渗透液,擦干。再喷涂显示液,在缺陷处即可显示红色形象。

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