The NMR shift arising from the electron angular momentum and electron spin dipolar-nuclear spin angular momentum interactions has been investigated for a $4d^1$system in a strong crystal field environment of tetragonal symmetry. A general formula for NMR shift is used to compute the NMR shifts along the (100), (010), (001), (110) and (111) axes. We find that from the computed results, the NMR shift along the (100) and (010) axes is consistent with each other in a strong crystal field environment of tetragonal symmetry, but the NMR shift along the (001) axis is about triply greater in magnitude than those along the (100) and (010) axes and is opposite in sign to those along (100) and (010) axes. In this work, we express the expansion coefficients $a_1^{(i)}$ and $b_1^{(i)}$ of $A_i$ and $B_i$ in terms of $g_m^{(i)}$ and $h_m^{(i)}$ and two matrices $c_{lm}$ and $d_{lm}$ of radial dependence. The NMR shift is also separated into the contributions of multipolar terms. We find that $1/R^3$ term contributes dominantly to the NMR shift along the (100), (010), (001) and (110) axes while along the (111) axis $1/R^5$ term dominantly contributes. However, the contribtions of the other terms may not be negligible.

The molecular orbital calculations for solid HF are performed by using the pseudolattice method considering the coulomb lattice sum. In order to obtain the reliable net atomic charges and lattice energy of one dimensional chains, the limited counting of interactions terms up to second neighbours for zig-zag chain and third neighbours for linear chain are sufficient in this calculation. In three dimensional solid HF, the contribution of interaction energy between non-hydrogen bonded neighbours to lattice energy is about 3.5% and the lattice energy of nonpolar structure is stablized by 2.05 kcal/mole compared with that of polar structure. And, this method is further tested and compared with the other methods.

Reactions of $MoOCl_5^{2-}$ with $[PW_{11}O_{39}]^{7-}\;and\;[SiW_{11}O_{39}]^{8-}$ have been studied spectrophotometrically and several transient complexes have been discovered. Transient species initially formed are probably $[Mo_2O_4(PW_{11}O_{39})_2]^{12-}\;and\;[Mo_2O_4(SiW_{11}O_{39})_2]^{14-}$. Spectra change gradually, indicating formation of transient isomers of $[PMoW_{11}O_{40}]^{4-}\;and\;[SiMoW_{11}O_{40}]^{5-}$, which again transform into the stable isomers. The transient isomers absorb light much more strongly than the stable isomers in the visible range.

An enhancement of through-bond interaction by bond angle distortion in pyrazine was examined using various MO methods. Results of MINDO/3 geometry optimization with an angle (${\alpha}$) at $C_2$ atom fixed to 120∼90$^{\circ}$ lead to distorted structures in which the distorted bond is brought closer toward lone pair orbital n of N atom. It was also found that the bond angle distortion increased the P character at the atom $C_2$, resulting in an increased vicinal overlap between n and the $C_2-C_3$ bond. The FMO patterns of ${\sigma}$ framework showed three-fold degeneracy, one of which was of different symmetry which mixes in the symmetry adapted pair, $n_+\;and\;n_-;\;both\;n_+\;and\;n_-$ orbitals thus can interact with both FMOs of the ${\sigma}$ framework. The LCBO-MO analysis with partial elimination of bonds, antibonds or both, however, revealed that the main interaction of $n_+$ was with the HO-${\sigma}$ and that of $n_-$ was with the LU-${\sigma}^{\ast}$ orbital of the ${\sigma}$ framework.

Superplastic alloys generally exhibit a three-stage sigmoidal variation of stress (f) with strain rate (s), the stages being named region 1, 2 and 3 according to the increasing order of stress or strain rate. In the recent years, two different types of papers have been published on the plastic deformation of Zn-22% Al eutectoid in region Ⅰ differing in strain-rate sensitivity m (= dln f/dln s). In this paper, the data of the two groups have been analysed by applying Kim and Ree's theory of superplastic deformation. (1) We obtained the parametric values of $X_{gj}/{\alpha}_{gj}\;and\;{\beta)_{gj}$ (g: grain boundary, j = 1,2 indicating flow units) appearing in Kim and Ree's theory [Eq. (2a)]. (2) It was found that the value of $X_{g^2}/{\alpha}_{g^2}$ is small for the group data with small m, i.e., ${\alpha}_{g^2}$, which is proportional to the size of flow unit g2, is large whereas ${\alpha}_{g^2}$ is small for the groups data with large m, i.e., the size of the flow unit g2 is small. In other words, the two types of behavior occur by the size difference in the flow units. (3) From the ${\beta}_{gj}$ value, which is proportional to the relaxation time of flow unit gj, the ${\Delta}H_{gj}^{\neq}$ for the flow process was calculated, and found that ${\Delta}H_{g^2}^{\neq}$ is large for the group data with small m whereas it is small for the group data with large m. (4) The flow-unit growth was studied, but it was concluded that this effect is not so important for differentiating the two groups. (5) The difference in ${\alpha}_{g^2}$ and in the growth rate of flow units is caused by minute impurities, crystal faults, etc., introduced in the sample preparation.

This study concerns about catalyic cracking of iso-octane over cation ($Cd^{2+},\;Ca^{2+}\;and\;La^{3+}$) exchange mordenites. It deals with mordenite shape selectivity and with kinetics of this catalytic reaction. The striking feature was that over the region of cracking temperature investigated, 523-665K, the yield of isobutene was predominant, relative to that of larger or smaller carbon chain(s). This permits kinetic analysis of the heterogeneous catalytic system in terms of the modified pulse-version microcatalytic chromatography. The observed activation energy ($E_a,\;KJ\;mol^{-1}$) was found to be 46 for Cd-M, 57 for Ca-M and 59 for La-M, respectively.

The anomalous behaviors of supercooled water are explained by using a two-solid-like structure model in which an equilibrium is assumed between open structures and closed structures. Besides these structures, small fraction of monomer exists in liquid water. The anomalies of liquid water are classified into two groups: structural and energetic. The structural anomalies appear in enlarged fashions in a supercooled state where the free volume is small.