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Transmission Frequency Properties of Elastic Waves along a Hetero-Phononic Crystal Waveguide 下载免费PDF全文
We investigate the propagation properties of hetero-phononic crystal waveguides by the improved eigen-mode matching theory, which can be used at same time to calculate both the transmission (reflection) coefficient and band structure. The numerical results show that the transmission frequency range is the same as the common range for two uniform waveguides composing the hereto-system, and the gap of any composite waveguide is also the gap of the hetero-phononic crystals waveguide. 相似文献
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中国古陶瓷是国际性的艺术收藏品,它的真伪判定是一个关键而且是首要的问题.传统的“目鉴”方法由于它的主观性,结论不容易取得共识,也不易对采用现代高新技术制作的赝品做出准确的鉴别.对古陶瓷进行现代的科技方法鉴定是必然的趋势,而且已取得重要的进展.热释光检测方法是一种绝对断代方法,它不依赖于数据库的建立.经过40余年的发展,热释光技术已从早期的常规方法发展出前剂量方法和高温峰测定方法,一种快速无损的二氧化碳激光加热检测法亦已取得重要的进展. 相似文献
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ELECTRONIC ENERGY SPECTRUM STRUCTURE OF THE TWO-DIMENSIONAL FIBONACCI QUASILATTICES WITH THREE KINDS OF ATOMS AND ONE KIND OF BOND LENGTH 下载免费PDF全文
After establishing the method of constructing a class of two-dimensional Fibonacci quasi-lattices, by means of a decomposition-decimation method based on the renormalization-group technique, we have studied the rule. of energy spectrum splitting for the two-dimensional Fibonacci quasilattices in the framework of single-electron tight-binding on-site model. Analytic results show that there are only six kinds of clusters and the electronic energy band consists of nine subbands. 相似文献
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According go the group representation theory, we derive the character formulae of representation-matrices of the期physical property gensors for the one-dimensional (1D) quasicrysgals. Based on this, we have calculated the numbers of independent components of representation-matrices for thermal expansion coefficient gensors, piezoelectric coefficient tensors and elastic constant tensors under 31 point-groups for the 1D quasicrystals. Moreover, we have deduced the particular matrix forms of these gensors under the 31 point-groups. This is an important complement of quasicrysgal physical property. 相似文献