Recently, the two negative-index relations have been deduced by the principle of the maximum entropy and confirmed by a lot of observation.

近年来，从熵最大原理的角度曾推导出其中的两个负指数关系，并被大量的观测所证实。

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Recent experiments that demonstrate the negative refraction of light has led a hot scientific debate to a close, and will bring the negative-index material a positive future.

近期关于光的负折射现象的论证实验给这个激烈的科学争论一个结论。并且对负反射物质的美好未来给予肯定。

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If water had a negative index of refraction, then a straw placed in a glass would appear to bend back under itself.

如果水具有负折射率，那么放在玻璃杯中的吸管似乎可能弯曲到自身下方。

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On the other hand, continued large investment gains helped 12 charities generate a negative index number--surpluses exceeding all donations for the reporting year.

FORBES: Personal Finance

Price returns for the Barclays Municipal 10-year Index were negative seven out of 13 years.

FORBES: Muni Bond Manager's Journal: Coupon Power Compounded

In that light, a negative yield of 0.55% on index-linked bonds seems a good investment.

ECONOMIST: A very unusual sign of confidence in economic policy