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关于圆形和方形城市工作区道路交通面积的解析与比较 总被引:1,自引:1,他引:0
对于城市规划来讲,事先预测其工作区内所需道路面积,以尽量避免实际交通网络中发生拥挤阻塞,具有重要意义,在本文,我们通过考虑一个城市通勤高峰时期的车辆交通情况,并通过利用走行中的车辆占用道路面积这一概念,基于一个相对现实的模型,从理论上对圆形方形城市工作区推导了所需的道路面积,并将两者加以比较,以发现与其交通网络结构相关的工作区的相对有效形状。 相似文献
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The recently proposed dynamic extended molecular orbital (DEMO) method is applied to the HCl(H2O) n and DCl(H2O) n (n = 0–4) clusters in order to explore the isotope effect on their structures, wavefunctions, and energies, theoretically. Since the DEMO method determines both electronic and nuclear wavefunctions simultaneously by optimizing all parameters including basis sets and their centres variationally, we can get the different nuclear orbitals for proton and deuteron as well as their electronic wavefunctions. The positions of the centres of nuclear orbitals show that the deuteron has weaker hydrogen bonding than the proton. There are three isomers in the case of n = 3 clusters, and less stable isomers have hydrogen transferred and non-transferred structures. In the conventional MO calculation, both hydrogen transferred and non-transferred isomers are calculated to be energy minima. When we have applied the DEMO method, only the hydrogen transferred structure is obtained for HCl(H2O)3, while both structures are optimized for DCl(H2O)3. Such strong H/D dependence on the structures of the HCl(H2O) n and DCl(H2O) n clusters can be expressed directly by using the DEMO method. The present application demonstrates that the DEMO method is a useful tool for analysing the anharmonicity and vibronic effects of a hydrogen bonding system. 相似文献
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MASANORI TACHIKAWA 《Molecular physics》2013,111(6):881-901
In order to explore the proton/deuteron (H/D) isotope effect on the structures, wavefunctions, and size dependence of water clusters, both electronic and nuclear wavefunctions are determined simultaneously. The optimized centres and the exponents for the nuclear orbitals indicate the Ubbelohde effect, i.e. the deuteron has weaker hydrogen bonding than the proton. Calculations are made also of hydrogen halide water clusters, Such as HF(H2O)n, HBr(H2O)n, (n = 0–4), and their deuterated species. Only the hydrogen transferred ring structure is optimized for the protonic HBr (H2O)3 cluster, while both the hydrogen transferred and the non-transferred structures are obtained for the deuterated DBr (H2O)3 cluster under the one-particle multi-component treatment. The proton in the HF molecule is localized more than those in the HCl and HBr molecules, and no hydrogen transferred structures are obtained for HF water clusters. 相似文献
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1.Introduction'TherearemanyskyscrapersinlargecitiessuchasTokyO,Beijingetc.,m~withrectangularparallelepipedshapesandsomewithfrustumshapes,whichiscausedbythesoaringofthelandprice.Inaverybigbuildingwithmanypeople,itiswgllknownthattheinnertrwhccannotbeignored… 相似文献
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