Precipitation chemistry in Japan was discussed on the basis of nation-wide monitoring results of Acid Deposition Survey of Japan Environment Agency in terms of ionic composition, concentrations and deposition of major ions. The volume-weighted mean ionic-composition of p recipitation collected fr om April 1989 to March 1993 was interpreted from the viewpoints of atmospheric chemistry to be composed of three contributions: 1) sea-salt derived ions including sodium, chloride, and magnesium ions, 2) sulfuric and nitric acids originated from man-made air p ollutants, sulfur dioxide and nitrogen ox ides, and 3) basic species such as ammonia and calcium c ompounds. Approximately 70% of t he origin al sulfuric and nitric acids were explained to have been neutralized to yield resultant pH of 4.76. pH at each site ranging from pH 4.5 to pH 5.8. A nnual mean concentrations and deposition of n on-seasalt sulf ate, nitrate, and ammonium were obtained, respectively, with their ranges in parentheses as follow s: 19.3(2.6-29.5), 14.1 (1.8-25.0), 18.3 (0.6-29.8) μmol L^-1, 26.1 (4.7-49.8), 19.4 (3.1-40.8), 2 5.9(1.1-55.4) mmol m^-2y^-1. Spatial distribution of annual mean concentration and deposition of th ese three ions w ere suggested highly u niform over the country from the ratios of the standard deviatio ns to the means. Seasonal variation of concentration and deposition of selected major ions o n Japan Sea were clarified, and discussed in terms of longrange transport from the Asian continent. Wintertime nonseasalt sulfate ion was shown to be remarkably increased in the concentration and deposition on Japan Sea side, and similar variations were observed for nitrate, ammonium, non-seasalt calcium i ons. O n the Pacific Ocean side, however, no distinct seasonal variations were found for these ions. Precipitation chemistry in Japan was compared with those in Europe, North America in terms of pH and pAi. The latter index was defined as the negative logarithm of the sum of non-seasalt sulfate and nitrate ion concentrations, which physically means the hypothetical pH under the assumption that no sulfuric and nitric acids in precipitation had been neutralized with atmospheric bases. In Europe, pAi was considerably low and the degree of neutralization was very small to offer lowest pH among the three regions of interest. In North America, pAi was likely to be lower than those in Europe, but the degree of neutralization wa s also high so a s to lower the pH. Both pH and pAi of t he precipitation in J apan were between those in t he two regions. Concentrations and deposition of non-seasalt sulfate and nitrate ions w ere discussed o n a global scale.

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A new NMR methodology was devised for configurational assignments of acyclic structures in natural products or synthetic compounds. Conventional methods based on NOEs often suffer from the ambiguity in assigning the configurations of compounds with acyclic structures and conformational alternation. Unlike these NOE analyses, the new methodology is based on the dihedral angle dependency of longrange carbon-proton coupling constants (^{2, 3}J_{C, H}). The combination of the coupling constants (^{2, 3}J_{C, H}, ³J_{H, H}) which are categorized to large, medium, or small allows to determine the relative stereochem istry among adjacent asymmetric centers or those separated by a methylene group. Hetero half-filter TOCSY (HETLOC) was shown to be the most effective for measuring ^{2, 3}J_{C, H} of protonated carbon system. For structures with quaternary carbons or weakly coupling protons, in which TOCSY in HETLOC fails to correlate relevant protons, phase-sensitive HMBC (HMQC optimized for long-range coupling)worked effectively. To evaluate the utility of the method in structural analysis of natural products, the relative configurations of acyclic portions of maitotoxin, the largest secondary metabolite known to date, were assigned by this method, which evidently demonstrated the validity of ^{2, 3}J, _{C, H} in the configurational and conformational analysis of organic compounds.

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The relation between particle size and catalytic properties of alumina-supported cobalt catalysts were investigated for steam reforming of ethanol, C₂H₅OH+H₂O→2CO+4H₂, in order to make effective use of ethanol solution produced by fermentation of biomass. The catalysts prepared from various Co-sources were examined for their performances in steady-state reaction, temperature-programmed reaction (TPR) and temperature-programmed desorption (TPD) at atmospheric pressure by use of a conventional flow reactor. The selectivity of the catalysts for the steam reforming of ethanol were determined as follows: Co (Carbonyl, CVD method)>Co (Chloride)>Co (Carbonyl)>Co (Acetate)>Co (Nitrate). The mean crystallite size of Co species on alumina varies depending on Co-sources and forms the reverse line to the selectivity, except for Co (Chloride). The peak of COx (mainly carbon dioxide) in the TPD spectrum, measured in the presence of water vapor, of ethanol adsorbed on the Co (Nitrate)catalyst shifts clearly to a higher temperature range with decreasing the crystallite size. This fact indicates that the selectivity for the steam reforming increases with the dispersion degree of the metal on alumina. The effect of the crystallite size on the catalytic properties is related to the strength of adsorption of COx and the catalytic activity for methanation of CO.

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A homogeneous precipitation using the hydrolysis of trimethyl phosphate (TMP) was studied. Stainlesssteel tubes containing 10 mM (1 M =1 mol dm^-3) of TMP and lanthanum chloride were maintained in a thermostated air bath. TMP was hydrolyzed above 130°C. Needle-like lanthanum phosphate of monazite type, 2-3 μm in size was quantitatively precipitated at 160°C for 4 h. Spherical aggregate was obtained under the crystallization control, keeping pH higher than 4 with sodium acetate buffer solution or adding methanol in large quantity (50 vol%). The mean size of the spherical aggregates was 0.63 μm (by sodium acetate buffer) and 0.85 μm (by methanol). When pH was lowered about 2.4 by the hydrolysis of TMP, the hydrolysis was accelerated by the effect of hydrogen ion.

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Solubilities of hardly soluble zirconium (IV) and hafnium (IV) complexes with water-soluble calix[n]arenes, Na_n1_n(n =4, 6, 8), such as (ZrO)₃(1₄H_-2)⋅7 H₂O, (HfO)₃ (1₄H_-2)⋅16H₂O, (ZrO)₄(1₆H_-2)⋅20H₂O, (HfO)₄(1₆H_-2)⋅22H₂O, (ZrO)₇(1₈H_-6)⋅16H₂O and (HfO)₇(1₈H_-6)⋅5H₂O were measured in water at 20°C and the solubilities of hafnium (IV) complexes were always found to be lower than those for corresponding zirconium (IV) complexes. The effect of hydrogen ion and several anions on the solubility was studied. The solubilities were the lowest at 0.1-0.3 M of hydrogen ion and little affected by the presence of chloride and nitrate ions. On the other hand, hydrogensulfate ion increased the solubilities, and the extent was different from zirconium (IV) to hafnium(IV) complexes. This was applied to the mutual separation of zirconium (IV) and hafnium (IV). Aluminium (III), titanium (IV) and iron (III)ions, usually found in a zirconium ore, were not precipitated with Na_n1_n, even in the presence of a large excess of zirconium (IV) ion.
By the precipitation me thod using Na_n1_n, almost all t itanium (III) and iron (III) and a large portion of aluminium (III) could be removed from zirconium (IV). The purified zirconium complex with Na₈1₈ was dissolved in an aqueous solution containing excess oxalic acid, then by passing the solution through an anion-exchange resin column, both zirconium (IV) and Na₈1₈ could be separately recovered in high yield.

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With a view to developing organic metals based on heteroaromatic-substituted tetrathiafulvalene (TTF) donors with a multidimensional network of heteroatomic interactions, we have investigated the syntheses and properties of 2, 3, 6, 7-tetra (3-thienyl)-, 2, 3-di (3-thienyl) -, 2, 3, 6, 7-tetra (2-thienyl)-, and 2, 3-di (2-thienyl) -tetrathiafulvalenes and their charge-transfer complexes. Single-crystal X-ray structure analyses of the tetra- and di (3-thienyl) derivatives revealed that the sulfur atoms in the thienyl groups contribute to intermolecular interactions via short S… S contacts. In the cyclic voltammograms, all the thienyl-TTFs showed two reversible one-electron redox waves at somewhat higher potentials than the corresponding ones of TTF. They thus behaved as relatively weak electron donors to form charge-transfer complexes with strong electron acceptors, such as 2, 3, 5, 6-tetrafluoro-7, 7, 8, 8tetracyanoquinordimethane (TCNQF₄) and iodine. The electrical conductivities of all the TCNQF₄ complexes were very low (10^-7-10^-8Scm^-1), but the iodine complexes of the two tetrathienyl derivatives showed high conductivities of the order of 10^-1-10^-2Scm^-1.

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Racemization of serine is an important reaction in the process of L-tryptophan synthesis from serine and indole. Broad substrate specificity amino acid racemase (EC 5.1.1.10) extracted from Pseudomonas putida was immobilized in polyacrylamide gel. Velocities of racemization of serine by bot h the native and immobilized enzymes were measured and analyzed. Two reactions catalyzed by both enzymes followed an equation of Michaelis-Menten type. For the native enzyme Michaelis constant (Km) of D-serine formation from L-serine was 4.1×10^-2 M, being Km of the reverse reaction 1.8×10^-2 M. Both Km and maximum reaction velocity (Vm) for the forward reaction showed approximately two-fold larger than those for the reverse reaction. In the immobilized enzyme the real Kms were 1.1-1.4 fold larger than those in the native enzyme, and the apparent Km increased with increasing a size of gel. Vms in the immobilized enzyme were 60-70% of those in the native enzyme. Extent of variations of Km and Vm was almost the same in forward and reverse reactions. By the measurement of the activity of the immobilized enzyme in a flow-reactor within 23 days the activity maintained stably within experimental errors.

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With the aim of developing preserving agents (ethylene-removing agents) for fruit and vegetables, the synthetic conditions and the properties of poly (4-vinylp3rridine) resins and resinbromine complexes obtained were investigated. Polymerization of 4-vinylpyridine with divinylbenzene as a cross linking agent was conducted in aqueous suspension systems, in methanol dispersion systems, and in aqueous systems added with some organic solvents. Resins of large granular size with considerable strengths were obtained in aqueous suspension systems. However, the specific surface areas of the resins were very small. In methanol dispersion systems, although resins of large specific areas were obtained, the granules were fragile and troublesome to handle. With the addition of t-pentyl alcohol and toluene to aqueous dispersion system, porous resins were obtained having sufficient size and strengths of granules for practical use. In this aqueous systems with t-pentyl alcohol and toluene, a part of divinylbenzene could be replaced with styrene and the resins of lower cost were obtained.1, 2-Dibromoethane was detected when a 4-ethylpyridine bromine complex as a model for the poly (4-vinylpyridine) bromine complex was brought into contact with ethylene gas. Poly (4-vinylpyridine) resins effectively adsorbed 1, 2-dibromoethane. Thus, it is suggested that the removal of ethylene by the resinbromine complex is due to the adsorption of 1, 2-dibromoethane, which is produced by the addition of bromine in the complex to ethylene. In addition, the rates of ethylene removal by the resinbromine complexes increased as the specific surface areas of the resins increased. This result indicates that the rate-determining step of the reaction is the diffusion of ethylene into the inside of the poly (4-vinylpyridine) bromine complexes.

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Enhancement of photosensitivity in a laser-beam sensitive layered photoreceptor consisting of a triphenylamine trisazo pigment has been performed. We focused an investigation on increasing a number of electron transfer sites for the extrinsic photocarrier generation between a carrier generation material (CGM) and a carrier transport material (CTM). To increase the number of CGMs at the surface of the CGM particle, we designed to control the particle size of the trisazo pigment for the CGM. As a result, quantum efficiency of a layered photoreceptor, of which carrier generation layer (CGL) was formed using the CGM dispersion ball-milled at 40°Cfor 258 hours, was proven to be 2.1 times larger than that ball-milled at room temperature. The magnitude of quantum efficiency was 0.8 at 3×10⁷Vm^-1. This value is equal to that using titanyl phthalocyanine, which currently exhibits the highest ph otosensitivity for a laser-diode beam. X-ray diffraction, absorption spectrum, electroabsorption spectrum and TEM observations of the high-sensitive trisazo pigment revealed that the secondary particle has a large vacant space which originates in a randomness of the primary particle size. In the layered photoreceptor, CTM penetrates not only into the CGL but also into such secondary particle after an overcoating of the carrier transport layer. This results in an increased density of photocarrier generation site in the CGL. Consequently, the layered photoreceptor using the trisazo pigment has achieved the highest photosensitivity resulting from an increase in number of the extrinsic electron transfer site.

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Preparation of antibacterial quaternary ammonium ion intercalation compound of layered aluminium dihydrogentriphosphate, AlH₂P₃O₁₀(a bbreviated to ADHP), was established.
Intercalation of quaternary ammonium ion was recognized when butylamine intercalation compound of ADHP reacted with aqueous solution of quaternary ammonium salt, or when ADHP reacted with the quaternary ammonium ion solution containing butylamine.
The obtained intercalation compounds were in dicated as Al[R']₂P₃O₁₀([R'] shows quaternary ammonium ion), and showed the sterilizing effect for several bacteria. The thermal stability of quaternary ammonium ions held between the interlayer region of ADHP was improved.

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Organofunctionalized silica gel was readily prepared from the organostannio silica gel, which had dib utyl or tributylstannio group, and (3-methacryloxypropyl) trimethoxysilane. The reaction in the presence of acid or base catalyst proceeded with the elimination of organotin group to produce the silica gel having a high content of the organofunctional group.

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Polyetherurethaneureas (PEUU-Si) including the tetramethyldisiloxane moiety in main chain were obtained from a typical two step polyaddition of polytetrahydrofuran (PTHF) to 4, 4'-methylene-bi s (phenylisocyanate) (MPI) in the presence of 1, 3-bis (3-hydroxypropy1)-1, 1, 3, 3-tetramethyldisiloxane (TMDS), using ethylenediamine (EDA) as a chain extension reagent. Polyaddition with a molar ratio of 1: 2: 1 for PTHF + TMDS: MPI: EDA gave the PEUU-Si in the mixed solvent of dimethyl sulfoxide and isobutyl methyl ketone, where the molar ratio of TMDS was changed from 0.2 to 1.0. From the XPS spectra and the contact angle measurements, it was found that the TMDS moiety was located on the surface of the PEUU-Si film in air and hydrophobicity was increased with increasing the molar ratio of the TMDS moiety. It was also found that PEUU-Si adsorbed bovine serum albumin. The tensile modulus of PEUU-Si showed E= 66-120 MPa.

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