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61.
In this paper we propose four-dimensional (4D) operators, which can be used to deal with sequential changes of topological relationships between 4D moving objects and we call them 4D development operators. In contrast to the existing operators, we can apply the operators to real applications on 4D moving objects. We also propose a new approach to define them. The approach is based on a dimension-separated method, which considers x-y coordinates and z coordinates separately. In order to show the applicability of our operators, we show the algorithms for the proposed operators and development graph between 4D moving objects. 相似文献
62.
基于采用微波能量预先弱化岩石的方法可以有效的降低岩石强度这一理论。本文先通过对花岗岩试件进行一定条件下的微波照射及劈裂试验,再利用ANSYS软件建立简化的二相岩石模型,模拟不同功率密度和照射时间下模型内部的温度分布和应力分布。结果表明:一定功率下,随着微波照射时间的增加,花岗岩试件抗拉强度逐渐降低,降低速度先快后慢,存在一个最佳照射时间范围。而采用高功率密度和短时间的微波照射时,模型内部的温度梯度增大,更易产生较高的温度应力,造成岩石损伤。模拟结果与试结果基本吻合,为微波辅助机械破岩技术提供一定的参考价值。 相似文献
63.
大孔吸附树脂A_(IA)的骨架主要是由丙烯酸酯和衣康酸双烯丙酯组成,它有好的吸附能力和淋洗性能。A_(IA)树脂按照Freundlich方程吸附VB_(12)。 相似文献
64.
给定n维分布F(x_1,…,x_n)与m维分布G(y_1,…,y_m),如果存在随机向量X=(X_1,…,X_n),Y=(Y_1,…,Y_m),使得X,Y分别以F,G为分布,X_i,Y_j(i=1,…,n;j=1,…,m)不相关并且不独立,则称F,G存在强耦合,且称n+m维随机向量(X_1,…,X_n,Y_1,…,Y_m)的分布就是F与G的一个强耦合。本文给出了F,G存在强耦合的一个充分条件和一个必要条件。特别地,当n≤2,m≤2时,文中所给的充分条件和必要条件恰好相重合。 相似文献
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66.
Recently, some case study of distance learning by internet line are widely carried out. Until now, the cultural or friendship exchange was a main purpose using distance learning program. In our research group, a distance learning which connected 3 sites (Nagasaki and Omura and Kagoshima in Japan) was tried as a domestic example[1]. In this case, internet exclusive line and portable telephone were utilized for DVTS technical support of distance learning. Nowadays, the international distance learning for education is also beginning. Our research group also tried international distance learning between Kwangju city of Korea and Nagasaki city of Japan using DVTS techniques with the tools of WebGIS education materials. 相似文献
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68.
Synthesis and anticonvulsant activity of 1-substituted benzyl-N-substituted-1,2,3-triazole-4-formamides 总被引:2,自引:1,他引:2
Substituted benzyl azids were synthesized through the reaction of substituted benzyl chloride and sodium azid,which subsequently underwent cyclization with ethyl propiolate and amidation to give thirteen 1-substituted benzyl-N-substituted-1,2,3-triazole-4-formamide derivatives (3a-3m). The structure of the synthesized compounds was confirmed by IR, H-NMR, MS and elemental analysis. Their anticonvulsant activity against maximal electrolshock (MES) induced seizure was tested and the result showed that all these compounds possess anticonvulsant activity in different degrees. Among those, the compounds containing chloro atoms on the phenyl ring were less potent in anticonvulsant activity, while introducing one or two fluorin atoms on benzyl system increased its activity. Furthermore, their activity decreased when there was substituent on the nitrogen atom of carboxamide, and the larger the substituent, the lower the activity. 相似文献
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