Ablative Rayleigh-Taylor instability at short wavelengths observed with moiré interferometry

One of the most important quantities to be measured for better understanding of the ablative Rayleigh-Taylor (RT) instability is the growth rate in the short wavelength region at which the RT instability is significantly reduced. The short wavelength ( 4.7-12 microm) RT growth rates for direct-drive targets were measured for the first time by utilizing the innovated moiré interferometry [M. Matsuoka et al., Rev. Sci. Instrum. 70, 637 (1999)]. These growth rates were reasonably well reproduced by the simulation that solves the Fokker-Planck equation for nonlocal heat transport.     

Polarization interferometric stellar coronagraph

A nulling stellar coronagraph based on polarization interferometry is proposed that has achromatic characteristics. The principle and the optical setup of the nulling stellar coronagraph are described. Experimental results with monochromatic and white light show the usefulness of the proposed method. A liquid-crystal device is used as a four-quadrant polarization mask, which is the key element of a polarization interferometric stellar coronagraph.     

Measurement of the B(e2) of (7)(lambda)Li and shrinkage of the hypernuclear size

We report on the first measurement of a hypernuclear gamma-transition probability. gamma rays emitted in the E2(5/2(+)-->1/2(+)) transition of (7)(Lambda)Li were detected by a large-acceptance germanium detector array (Hyperball), and the lifetime of the parent state ( 5/2(+)) was determined by the Doppler shift attenuation method. The obtained result, 5.8(+0.9)(-0.7)+/-0.7 ps, was then converted into the reduced transition probability [ B(E2)] to be B(E2;5/2(+)-->1/2(+)) = 3.6+/-0.5(+0.5)(-0.4) e(2) fm(4). Compared with the B(E2) of the corresponding E2(3(+)-->1(+)) transition in the 6Li nucleus, our result gives evidence that the size of the 6Li core in (7)(Lambda)Li is smaller than the 6Li nucleus in the free space.     

Switching extended 1,3-diequatorial and bent 1,3-diaxial states of a disubstituted hinge sugar by ligand exchange reactions on Pt(II)

The bent conformation of a trisaccharide containing 2,4-diaminoxylopyranoside, in which both end sugars are presented in 1,3-diaxial orientation, is fixed by chelation of the diamino groups to Pt(II) and unfixed by a ligand exchange reaction with NaCN or thiourea giving its extended conformation.     

Design of combinatorial shadow masks for complete ternary-phase diagramming of solid state materials

We report on a novel mask design for the combinatorial synthesis of a ternary composition spreads library, which allows such libraries to be deposited through a series of simple masks on a rotatable mount. This eliminates the use of complicated actuation of a heated substrate. In our configuration, this design leads to a standard linear phase diagram by varying the growth rate of each constituent nearly linearly from 0 to 100% at a triangular area on the substrate. Film growth occurs as a series of cycles in which one molecular layer of the material is deposited over the entire area of the spread by a synchronization of the mask movement, target exchange, and laser pulses. The technique has been applied to the synthesis of photoluminescent TbCa(4)O(BO(3))(3)-ScCa(4)O(BO(3))(3)-PrCa(4)O(BO(3))(3), demonstrating its value for the mapping of direct relationship between composition and the light-emitting property.     

Bioactive saponins and glycosides. XIV. Structure elucidation and immunological adjuvant activity of novel protojujubogenin type triterpene bisdesmosides, protojujubosides A, B, and B1, from the seeds of Zizyphus jujuba var. spinosa (Zizyphi Spinosi Semen)

Following the elucidation of jujubosides A1 and C and acetyljujuboside B, novel protojujubogenin type triterpene bisdesmosides, protojujubosides A, B, and B1, were isolated from Zizyphi Spinosi Semen, the seeds of Zizyphus jujuba Mill. var. spinosa Hu. The structures of protojujubosides A, B, and B1 were determined on the basis of chemical and physicochemical evidence, which included the conversion of protojujubosides to known jujubosides using enzymatic hydrolysis. Protojujubosides A and jujubosides A, B, and C were found to show potent immunological adjuvant activity.     

Chemorheological treatment of crosslinked EPT

Stress relaxation mechanisms were investigated on three types of (EPT) ethylene–propylene terpolymers in air at 109°C. These polymers differe only by the structure of the crosslinkage in which there is a carbon–carbon bond, a polysulfide linkage (? S?? ) or a monosulfide linkage (? S? ). All the stress relaxation of peroxide-cured EPT polymer was not due to the oxygen-induced cleavage of the main chain but to a physical flow. In the case of sulfur-cured EPT polymer, the relaxation curve is divided into three straight lines when the procedure X is used and log f(t)/f(0) is plotted linearly with time. It was concluded that this graph was in agreement with an interchange reaction of the polysulfide linkage by an oxidative cleavage of the monosulfide linkage. On the other hand, a TT-cured EPT polymer gave a plot with a straight line. This stress relaxation could be explained by an oxidative cleavage of the monosulfide linkage.     

Network structure and mechanical properties of allophanate-cured polyurethane rubber

An allophanate-cured polyurethane (PU) has been prepared. The relationship between trifunctional network structure and mechanical properties is discussed. Mooney-Rivlin constants C₁ and C₂ are determined from stress-strain isotherms. C₂ is approximately constant. The average value of structure factor A₃ in the limit at large deformation is 0.432, in fair agreement with the theoretical prediction of 1/3. The structure factor A′₃ of all PU samples becomes roughly unity in the limit at small deformation. The experimental results are interpreted by the recent Flory theory (a fluctuation-constraint model of junctions). The κ parameter decreases with increasing crosslink density; the ξ parameter is small and approaches zero. Increasing crosslink density tends to cause phantom deformation for extended PU networks. However, the absolute value of the reduced stress in the limit at large deformation (or for the equivalent phantom network) [f] is believed to be overestimated for PU networks with high crosslink density. The origin of this behavior is discussed in detail.     

Monte-Carlo-Simulierung der Pfropfreaktionen von Sterol auf Celluloseacetat

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