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红外分光光度法测定水中石油类时,如何检验校正系数?

答案

参考答案:

分别准确量取纯正十六烷、姥鲛烷和甲苯,按5∶3∶1(V/V)比例配成混合烃。以四氯化碳为溶剂配成适当浓度范围的混合烃标准系列。在2930cm-1、2960cm-1、3030cm-1处分别测量混合烃系列溶液的吸光度,按原校正系数计算石油类浓度,将测定值与配制值比较。如测定值的回收率在90%~110%范围内,则原校正系数可采用。否则重新测定校正系数并检验,直到符合要求。也可用正十六烷、异辛烷和苯按65∶25∶10(V/V)的比例配制混合烃,然后按相同方法检验校正系数。

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The U.S. Supreme Court’s decision Monday to let stand a ruling in an online defamation case will make it more difficult to determine correct legal jurisdictions in other Internet cases, legal experts said.

By opting not to take the case, the high court effectively endorsed a lower court’s decision that a Colorado company that posts ratings of health plans on the Internet could be sued for defamation in a Washington court. The lower court ruling is one of several that makes it easier for plaintiffs to sue Web site operators in their own jurisdictions, rather than where the operators maintain a physical presence.

The case involved a defamation suit filed by Chehalis, Wash.-based Northwest Healthcare Alliance against Lakewood, Colo.-based Healthgrades. com The Alliance sued in Washington federal court after Healthgrades. com posted a negative ranking of Northwest Healthcare’s home health services on the Internet. Healthgrades. com argued that it should not be subject to the jurisdiction of a court in Washington because its publishing operation is in Colorado.

Observers said the fact that the Supreme Court opted not to hear the case only clouds the legal situation for Web site operators.

Geoff Stewart, a partner at Jones Day in Washington, D. C. , said that the Supreme Court eventually must act on the issue, as Internet sites that rate everything from automobile dealerships to credit offers could scale back their offerings to avoid lawsuits originating numerous jurisdictions.

Online publishers also might have to worry about being dragged into lawsuits in foreign courts, said Dow Lohnes & Albertson attorney Jon Hart, who has represented the Online News Association.

"The much more difficult problems for U. S. media companies arise when claims are brought in foreign countries over content published in the United States," Hart said. Hart cited a recent case in which an Australian court ruled that Dow Jones must appear in a Victoria, Australia court to defend its publication of an article on the U. S.--based Walt Street Journal Web site.

According to Hart, the potential chilling effect of those sorts of jurisdictional decisions is substantial. "I have not yet seen publishers holding back on what they otherwise publish because they’re afraid they’re going to get sued in another country, but that doesn’t mean it won’t happen if we see a rash of U. S. libel cases against U. S. media companies being brought in foreign countries," he said.

Until the high court decides to weigh in directly on this issue, Web site operators that offer information and services to users located outside of their home states must deal with a thorny legal landscape, said John Morgan, a partner at Perkins Coie LLP and an expert in Internet law.

Which of the following best defines the word "libel" (Paragraph 8)()

A. Slander

B. Publicity

C. Option

D. Generosity