The governing rheological property for extrusion drawing in film-casting process is proposed in this study. The experiment
of film-casting process using the high-pressure process low-density polyethylene (LDPE) was performed. The non-isothermal
viscoelastic simulation of the film casting experiment was also carried out to explain the experimental results. Film width
reduction phenomenon in an air gap, so-called neck-in behavior, was investigated by using the simulation of the LDPE and the
model fluids exhibiting specific viscoelasticity. The neck-in phenomenon was also examined using theoretical model based on
force balance and deformation type of a film. As a result, the neck-in normalized by the air gap was in good correlation with
the ratio of planar to uniaxial elongational viscosity rather than the strain hardening nature of uniaxial elongational viscosity. 相似文献
Summary: The formation of a molecular‐complex crystalline phase of syndiotactic polystyrene (sPS) that contains a stable nitroxide radical compound, 2,2,6,6‐tetramethylpiperidinyl‐N‐oxyl (TEMPO), is confirmed by IR and electron spin resonance (ESR) spectroscopy, X‐ray diffractometry, and thermogravimetric analysis. Through a guest exchange procedure assisted by a plasticizing agent, the original guest (chloroform) contained in the starting clathrate phase is completely replaced by TEMPO. Although the conformational regularity of the sPS helices in the resultant crystalline phase that contains TEMPO is similar to that in the starting clathrate phase, the host lattice expands in the 010 direction. The guest TEMPO molecules exhibit a significantly broadened ESR signal because of their highly concentrated state in the complex crystalline phase.
Thermogravimetric measurement of a powder sample of the sPS/TEMPO complex. 相似文献
Electron spin resonance (ESR) of Fe3+ ions and of radiation-induced centers in quartz (E’, peroxy and Al centers) was studied to distinguish between burnt and unburnt stone tools and to determine their age. The yellow stone tool with a reddish edge discovered at the paleolithic site in Kamitakamori, northern Japan, was investigated. The ESR spectrum intensity of Fe3+ ions around g=4.3 and the color of the material changed at 600°C and 240°C, respectively, which indicates that the red part was heated at 240–600°C. The E′ center in the red part was used for dating because isochronal annealing experiments showed low thermal stability of the Al center and overlap of broad signals at g=2.0086 onto the peroxy center. Assuming the same efficiency of defect formation in the red part as of that in the laboratory-heated material at 450°C, the obtained age of 520–770 ka is in concordance with the ages of the tephra layers at the site. 相似文献
Acid treatment of (IR, 3S,1′S)-1-(1′,2′-Epoxyethyl)-1,2,2-trimethyl-3-acetoxymethyl-cyclopentane ) has been shown to yield three products (, , ), among which and are 1-oxa-bicyclo[3.3.0]octane derivatives formed successive methyl migrations followed by an oxorane ring closure. 相似文献
A unique "single-chain quantum magnet" was formed by an alternating arrangement of high-spin FeII/low-spin FeIII ions. Although the predominant spin-carrier components (high-spin FeII) possess easy-plane magnetic anisotropy (D > 0), twisted arrangement of easy-planes along the chain axis defines a novel class of one-dimensional Ising system. 相似文献
The system consists of an AT-cut quartz piezoelectric crystal, oscillator and frequency counter. The surface of the palladium-plated electrodes is oxidized anodically, and anti-Candida antibody is immobilized onto the surface. The crystal sensor is dipped into Candida suspension and the surface mass increase, caused by immuno-adsorption of Candida, is measured by the decrease in the resonant frequency of the crystal. The frequency shift is correlated with C. albicans concentrations in the range 106?5 × 108 cells cm?3. The crystal sensor showed no response to Saccharomyces cerevisiae. 相似文献
Single crystals of the quaternary compound Ba8Cu3In4N5 were prepared by heating Ba, Cu, and In in a Na flux at 1023 K under 7 MPa of N2, and by slow cooling from this temperature. The crystal structure was analyzed by single-crystal X-ray diffraction. It crystallizes in an orthorhombic cell (space group Immm (No. 71), Z=2) with a=4.0781(6), b=12.588(2), and c=19.804(3) Å at 298 K. The structural formula is expressed as Ba8[CuN2]2 [CuN]In4. Nitridocuprates of one-dimensional chains 1∞[CuN2/2] and isolated units 0[CuN2], and one-dimensional indium clusters 1∞[In2In4/2] are contained in the structure. A split-site model applied for the arrangement of 1∞[CuN2/2] chains suggested that there is a short-bond, long-bond alternation of the Cu-N bondings. The electrical resistivity of Ba8Cu3In4N5 was 3.44 mΩ·cm at 298 K. A metallic temperature dependence of the resistivity was observed down to 10 K. 相似文献