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Statistical Analysis of the Effect of Mineral Admixtures on the Strength of the Interfacial Transition Zone 总被引:1,自引:0,他引:1
Microscopic evidence indicates that the thickness of the interfacial transition zone (ITZ) between the aggregate and the cement paste is modified when mineral admixtures partially replace portland cement. Unfortunately, there is limited information on the significance of these microscopic modifications to the mechanical properties of the ITZ. This research reports experimental results on the shear and tensile strength of the ITZ as affected by the addition of the following mineral admixtures: silica fume, fly ash, and natural pozzolan. Statistical analysis was used to identify the significant parameters affecting the tensile and shear strength of the ITZ. Experimental results indicate that not only does the incorporation of silica fume and fly ash increase the strength of the ITZ, these mineral admixtures have a greater influence on the strength increase of the ITZ than in the strength increase of the cement paste. 相似文献
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Solid solutions NaCl—CdCl2 were studied in an interval of CdCl2 concentrations of 0.05—3 mol.% by Raman spectroscopy. The molecular form Na2CdCl4 decomposes: Na2CdCl4 2Na+ + Cd2+ + 2Cl2
– + 2e–; 2Na + 2e– 2Na0. Free sodium atoms form color centers of crystal (F centers) in the region of jumpwise changing the partition coefficient of CdCl2 in NaCl (K jump). 相似文献
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By means of improved ligand-field theory, the "pure electronic" pressure-induced shifts (PS's) and the PS's due to electron-phonon interaction (EPI) of R1 line and R2 line of YAG:Cr3 have been calculated, respectively.The calculated results are in very good agreement with the experimental data. It is demonstrated that the admixture of |t22(3T1)e4T2> and |t322E> bases in the wavefunction of R1 level of YAG:Cr3 and its change with pressure play a key role for the PS of R1 line. The behaviors of the "pure electronic" PS of R1 line and the PS of R1 line due to EPI are different. It is the combined effect of them that gives rise to the total PS of R1 line, which has satisfactorily explained the experimental results. The systematic analyses and comparisons between the feature of R1-line PS of YAG:Cr3 and the ones of three laser crystals (GSGG:Cr3 , GGG:Cr3 and ruby) have been made, and the origin of the difference between them has been revealed. 相似文献
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A class of models of porous media based on the concept of an ensemble of pores with a certain distribution of the main geometric parameters (for example, the pore size) is considered. The cases of pores saturated with single-and two-phase multicomponent liquid mixtures are investigated. The properties of equilibrium states of the mixture are derived from the minimum free energy condition and the transfer laws from the decreasing free energy condition. The hydrodynamic connectivity of the pores is described by two types of kernels: one describes the spatial connectivity and the other the connectivity in an elementary macrovolume. Analytically and numerically, the one-dimensional problems of establishment of a steady-state regime, propagation of a passive admixture, and two-phase flow (an analog of the Buckley-Leverett problem) are investigated. A relationship between the models in question and relaxational filtration models is demonstrated. A simple model of capillary hysteresis related with the non-monotonicity of the pore area to volume ratio function is proposed. 相似文献
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ⅡA,ⅡB族第一激发态原子中的角动量耦合 总被引:1,自引:1,他引:0
随着主子量子数n增大,ⅡA,ⅡB族第一激发态原子中价壳电子间库仑排斥作用减弱,电子自身自旋-轨道相互作用相对增强,从而导致其对LS耦合方式的逐渐偏离和ij耦合方式的逐渐介入,组态混合方法可用来定量计算LS耦合方式的偏离程度。 相似文献
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Is Cd2 truly a van der Waals molecule? Analysis of rotational profiles recorded at the , transitions
Rotational profiles of the 228Cd2 isotopomer recorded in the (υ′, υ″) = (26, 0), (27, 0), (42, 0), (45, 0), (46, 0), (48, 0) vibrational bands of the transition were analysed. As a result, the , , , , and excited- as well as the ground-state rotational constants of the (114Cd)2 were determined. The analysis allowed determining the absolute values for the and excited- and ground-state bond lengths, respectively. The obtained result – the – distinctly shorter than that obtained with assumption of pure ground-state van der Waals bonding, supports a theoretical prediction of a covalent admixture to the bonding. Analysis of the partially-resolved rotational profile recorded in the (υ′, υ″) = (38, 0) band of the same isotopomer recorded at the transition allowed estimating the rotational constant in the B1u state. 相似文献
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By successively taking into account various interactions for d2 ions in trigonally distorted cubic crystal fields, detailed analyses, derivations and calculations of the zero-field splitting (ZFS) and g factors of the ground state have been carried out; and their physical essentials and origins have been clearly revealed. The mistakes and shortcomings in some references have been corrected and improved. The calculated results are in excellent agreement with experimental data and much better than those of previous work. It is found that both the combined action of the trigonal field and spin-orbit interaction and the interaction between the ground state and excited states are quite necessary for causing ZFS of the ground state, and both the spin-orbit interaction and the admixture between the ground state and excited states are necessary for causing the deviation of g factors of the ground state from spin-only values. 相似文献
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詹兆宗 《宁波大学学报(理工版)》2005,18(2):244-247
介绍了C/S和B/S混合结构对改变饭店管理模式的作用,讨论了用PB8.0构造C/S和B/S混合结构的基本体系,分析了C/S结构饭店管理系统向C/S和B/S混合结构转换中的移植策略和基本步骤. 相似文献