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Based on the Least Square Mean method which is broadly applied on the active noise control technology, the paper calculated the frequency selective LMS algorithm and created the model for the application of the algorithm on active noise control; and was modeled and analyzed the adaptive attenuation simulation with single tone noise signal and narrow band noise signal demonstrating on the platform of Matlab/Simulink, after the control parameters of filter performance parameters and step size and filter length of adaptive filter was decided. The simulation result showed obvious counteract effect of noice signal，it was identical with theoretic solution and the presented algorithm was valid. Keywords-vehicle interior noise; frequency selective noise control ; active noise controlI.

Karst tiankengs are rare natural habitats, having a local microclimate different from surrounding regions. A contrast study on plant communities at the inside and outside of the primitive tiankeng was carried out by performing the qualitative analysis of species compositions of arborous and shrub layers. We found that plant communities in the primitive tiankeng belong to the subtropical moist evergreen broad-leaf forest, whereas those outside the tiankeng belong to subtropical semi-moist needle-broadleaved mixed forest. Trapped habitat of primitive karst tiankeng protects the plant communities significantly different from those in external karst ecosystems, so karst tiankeng has the great value in the plant species protection. Although the trapped habitat decreases plant species abundance inside tiankeng to some extent, highly diverse shrub species are present in the inside-tiankeng plant communities, and the primitive karst tiankeng plays an important role in the plant diversity protection. The primitive karst tiankeng is an important refugia for plant not only as a plant species protection library, but a plant diversity protection library. When implementing measures for the reduction of damages to biodiversity due to global climate changes and human activities, more attention should be paid to the primitive karst tiankeng as a small ecological refugia and biodiversity protection library.

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