The ECB has been very explicit about its separation principle since the launch of its non-conventional tools including covered bond purchasing program and also SMP.

欧洲央行非常明确地表示了利率工具和非传统工具（如在二级市场购买债券）用途的不同性。

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In the valence bond treatment, explicit recourse is made to classical, localized bond structure.

价键法明显依赖经典的定域结构。

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In America, Britain and Germany ten-year bond yields under 2% are now lower than the explicit (or implicit) inflation targets of their central banks.

ECONOMIST: The remarkable demand for low-yielding government bonds