问题 问答题 简答题

水基油墨有什么特点?

答案

参考答案:

以水作为溶剂的油墨,称作水基油墨。这种油墨是利用油墨中水分在干燥过程中挥发,使已溶解助树脂固化,形成皮膜。这种油墨也称为水性油墨。水基油墨由水性树脂、颜

料、辅助剂、水基系统添加剂经调合而成的。

水基油墨的优点是:由于溶剂大部分是水,所以污染少利于环境保护,油墨对丝网的通过性及再现性等都比较好。其缺点是:油墨光泽差、精度低、附着性差,必须使用耐水印版。印刷纸张时容易引起纸张翻卷弯曲,而影响套印质量。另外油墨中水的蒸发速度较慢,所以干燥时间较长。

问答题
单项选择题

It was the best of times or, depending on your political and philosophical outlook, one of the foulest and most depraved. Rebellion seemed to be leaping from city to city, continent to continent, by some fiery process of contagion. Radical students filled the streets of Mexico city, Berlin, Tokyo, Prague. In the U. S. , Chicago swirled into near anarchy as cops battled antiwar demonstrators gathered at the Democratic Convention. And everywhere from Amsterdam to Haight-Ashbury, a generation was getting high, acting up.

So, clearly, it was the year from hell--a collective "dive into extensive social and personal dysfunction," as the Wall Street Journal editorialized recently. Or, depending again on your outlook, a global breakthrough for the human spirit. On this, the 25th anniversary of 1968, probably the only thing we can all agree on is that ’68 marks the beginning of the "culture wars," which have divided America ever since.

Both the sides of the "culture wars" of the ’80s and ’90s took form in the critical year of’68. The key issues are different now--abortion and gay rights, for example, as opposed to Vietnam and racism--but the underlying themes still echo the clashes of ’68: Diversity vs. conformity, tradition vs. iconoclasm, self-expression vs. deference to norms. "Question authority," in other words, vs. "Father knows best."

The 25th anniversary of ’68 is a good time to reflect, calmly and philosophically, on these deep, underlying choices. On one hand we know that anti-authoritarianism for its own sake easily degenerates into a rude and unfocused defiance: Revolution, as Abbie Hoffman put it, "for the hell of it." Certainly ’68 had its wretched excesses as well as its moments of glory: the personal tragedy of lives undone by drugs and sex, the heavy cost of riots and destruction. One might easily conclude that the ancient rules and hierarchies are there for a reason--they’re worked, more or less, for untold millenniums, so there’s no point in changing them now.

But it’s also true that what "worked" for thousands of years may not be the best way of doing things. Democracy, after all, was onee a far-out, subversive notion, condemned by kings and priests. In our own country, it took all kinds of hell-raising, including a war, to get across the simple notion that no person is morally entitled to own another. One generation’s hallowed tradition--slavery, or the divine right of kings--may be another generation’s object lesson in human folly.

’68 was one more awkward, stumbling, half-step forward in what Dutschke called the "long march" toward human freedom. Actually, it helped inspire the worldwide feminist movement.

The writer’s attitude towards the issue is()

A. impartial

B. subjective

C. biased

D. puzzling