Quantum-chemical calculations for paramagnetic 13C NMR chemical shifts of iron-bound cyanide ions of iron porphyrins in ground and low-lying excited states containing ferric (dxy)2(dxz,yz)3 and (dxy)1(dxz,yz)4 configurations

Accurate quantum-chemical calculations were carried out for bis(cyanide) and cyanide-imidazole Fe(III) porphyrins in the ground and low-lying excited states including both the ferric (dxy)2(dxz,yz)3 and (dxy)1(dxz,yz)4 configurations. The trans-ligand effect on the paramagnetic 13C NMR chemical shifts of the iron-bound 13CN- was well reproduced by the present calculations. Further, in bis(cyanide)(meso-tetraethyl) Fe(III) porphyrin, which has a ruffled porphyrin ring, the (dxy)1(dxz,yz)4 configuration is included in the ground state, and the alternative (dxy)2(dxz,yz)3 configuration is located closely in energy to the ground state. Ruffling of porphyrin rings extremely affects the 13C chemical shift of iron-bound CN in the (dxy)1(dxz,yz)4 configuration but not in the (dxy)2(dxz,yz)3 configuration.     

Symmetry Classification for Jackson Integrals Associated with the Root System BC n

The Jackson integrals associated with the non-reduced root system are defined as multiple sums which are generalization of the Bailey's very-well-poised ₆₆ sum. They are classified by the number of their parameters when they can be expressed as a product of the Jacobi elliptic theta functions. The sums which appear in the classification list coincide with those investigated individually by Gustafson and van Diejen.     

Energetic protons from a few-micron metallic foil evaporated by an intense laser pulse

With detailed experimental studies and hydrodynamics and particle-in-cell simulations we investigate the role of the prepulse in laser proton acceleration. The prepulse or pedestal (amplified spontaneous emission) can completely evaporate the irradiated region of a sufficiently thin foil; therefore, the main part of the laser pulse interacts with an underdense plasma. The multiparametric particle-in-cell simulations demonstrate that the main pulse generates the quasistatic magnetic field, which in its turn produces the long-lived charge separation electrostatic field, accelerating the ions.     

Spontaneous deformation of the fermi surface due to strong correlation in the two-dimensional t- J model

The Fermi surface of the two-dimensional t- J model is studied using the variational Monte Carlo method. We study the Gutzwiller-projected d-wave superconducting state with an additional variational parameter t(')(v) corresponding to the next-nearest-neighbor hopping term. It is found that the finite t(')(v)<0 gives the lowest variational energy in the wide range of hole-doping rates. The obtained momentum distribution function shows that the Fermi surface deforms spontaneously. It is also shown that the Van Hove singularity is always located very close to the Fermi energy. Using the Gutzwiller approximation, we show that this deformation is due to the Gutzwiller projection operator or the strong correlation.     

分子束外延法在Sapphire衬底上生长的Zn1-xMgxO薄膜折射率及厚度的测试

利用偏振光椭圆率测量仪对分子束外延(MBE)法在Sapphire衬底上生长的Zn1-xMgxO薄膜的薄膜折射率和厚度进行了测试.结合ICP法测得的薄膜中的Mg组成量,经数值拟合,导出表征薄膜厚度与薄膜生长条件、薄膜折射率与薄膜中的Mg组成量之间关系的曲线,为MBE法在Sapphire衬底上生长Zn1-xMgxO薄膜时控制薄膜厚度以及在制作Zn1-xMgxO薄膜的波导时控制薄膜的折射率提供了理论依据.     

Metabolic activation of chemical carcinogens and binding of metabolites with nucleic acid bases

A free radical was produced enzymatically by incubating benzo(a)pyrene with liver microsomes. This radical, identified as the 6-oxybenzo(a) pyrene radical, was sufficiently reactive to bind covalently with nucleic acid bases. Similar reactive free radicals were produced enzymatically from anthanthrene and 10-aza-benzo(a)pyrene, which are carcinogenic in spite of lacking so-called “bay regions.” Hepatocarcinogens such as 3′-methyl-4-dimethylaminoazobenzene and related compounds, naphthylamines, and 2-acetylaminofluorene yield free radicals after being incubated with liver microsomes. Thus, various kinds of chemical carcinogens are found to be converted to free radicals, suggesting causal significance for the formation of free radicals in chemical carcinogenesis.     

Determination of selenium in sediments by fluorimetry with 2,3-diaminonaphthalene after an improved pretreatment by tellurium coprecipitation

Summary An improved fluorimetric method for the determination of selenium in estuary sediments and sedimentary core samples is described. For the separation of selenium, coprecipitation with tellurium-ascorbic acid method gave satisfactory results. The status of the pollution caused by selenium in Nagoya area, which is one of the most industrially active areas in Japan, was estimated, based on the results obtained with this method. Several g/g of selenium were determined in the sediments. Interferences by foreign ions were eliminated by the coprecipitation procedure. Selenium added was recovered by 95–101%.

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Selenbestimmung in Sedimenten mit Hilfe der Fluorimetrie mit 2,3-Diaminonaphthalin nach einer verbesserten Vorbehandlung durch Tellur-Mitfällung

Zusammenfassung Gehalte bis zu mehreren g/g Selen wurden nach dem verbesserten Verfahren in den Sedimenten des Hafens von Nagoya bestimmt. Störungen durch Fremdionen wurden durch das Mitfällungsverfahren mit Tellur/Ascorbinsäure verhindert. Zugesetztes Selen wurde zu 95 bis 101% wiedergefunden.

     

An investigation of the level scheme of 72As through the 72Ge(p,nγ)72As reaction

The level scheme of the doubly odd nucleus ⁷²As has been investigated by the (p, nγ) reaction up to an excitation energy of about 800 keV. Spin and parity assignments were made by measuring internal conversion coefficients and by an analysis of the (p, n) cross sections through the statistical model of the compound nuclear reaction. The level scheme obtained was interpreted by a simple model calculation based on the shell model.     

Separation and determination of selenium(IV) in environmental water samples by an anion-exchange resin modified with bismuthiol-II and diaminonaphthalene fluorophotometry

Summary Selenium(IV) in environmental water samples was determined fluorometrically following its collection by the use of a new functional resin. The resin was easily prepared from an anion-exchange resin by modification with bismuthiol II. A highly selective adsorption of selenium(IV) was achieved by the formation of stable selenotrisulfide from bismuthiol II and selenium(IV) on the resin. The method was successfully employed for the determination of Se in river water and waste water.

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Trennung und Bestimmung von Selen(IV) in Umwelt-Wasserproben mit Hilfe eines Bismuthiol II-modifizierten Anionenaustauschers und der Fluorophotometrie mit Diaminonaphthalin

Zusammenfassung Das Selen wurde mit Hilfe eines mit Bismuthiol II modifizierten Anionenaustauschers angereichert und fluorometrisch bestimmt. Die Adsorption, die auf der Bildung eines stabilen Selentrisulfids beruht, ist sehr selektiv. Das Verfahren wurde mit gutem Erfolg zur Selenbestimmung in Fluß- und Abwasser eingesetzt.

     

Nylon-6 α-phase crystal: Chain repeat distance and modulus in the chain direction at low temperature

The chain repeat distance in the α-phase crystal of nylon-6 was measured from ?150 to 150°C. The distance increases with decreasing temperature, indicating that the chain is not a complete planar zigzag but is twisted at room temperature. The relation between the distance and temperature changes at about ?110°C and again near 40°C. Both changes seem to be related to the mechanical dispersions of the material. Young's modulus in the chain direction is 270 GN/m² at ?150°C, or 14% less than the theoretical value given by Tashiro and Tadokoro for the planar zig-zag structure. It is not possible to determine from the (0k0) diffraction intensities whether the amide or methylene moieties are the more important in the chain twisting.