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111.
In stereoscopic images, the crossing point of the viewing directions of the two eyes determines the perceived depth. Assuming that accommodation is affected by the positions of the crossing point, the effect of crossing point on minimum angle of resolution (MAR) was investigated. For 40 participants, MAR was measured by two‐alternative forced choice where Snellen optotype E of up and down directions were used as two kinds of stimuli. As the crossing point of the viewing direction of the left and right eyes moves farther from the sample display, the ability to identify the direction of letter E decreases at the optotype of the same line thickness. The change of MAR shows linear trends with respect to the optical power change that are the reciprocal of the distance from the participant to the crossing points located out of screen and on screen.  相似文献   
112.
The interfacial reaction between styrene/maleic anhydride copolymer (SMA) and amine-terminated butadiene-acrylonitrile copolymer (ATBA) was observed using Fourier transform infrared (FTIR) imaging spectroscopy. The anhydride and amine reacted to form an imide. Each component was detected using a characteristic wavenumber, which was 1601 cm -1 for SMA, 2237 cm -1 for ATBA, and 1701 cm -1 for the imide. FTIR images were taken as the reaction proceeded at 150, 160, 170, and 180°C. At low temperatures (150 and 160°C), diffusion-controlled kinetics were observed since interdiffusion between the reactants did not appear in the images. On the other hand, both the diffusion front and the reaction front are observed in the images at high reaction temperatures (170 and 180°C), which indicates that the kinetics became reaction-controlled rather than diffusion-controlled. Absorbance profiles were extracted from the images and used for the calculation of the extent of reaction. The data were analyzed using the Frederickson and Milner theory based on the assumption of diffusion-controlled kinetics, and this theory fit the low reaction temperature data.  相似文献   
113.
A multi-fluid nonrandom lattice fluid model with no temperature dependence of close packed volumes of a mer, segment numbers and energy parameters of pure systems is presented. The multi-fluid nonrandom lattice fluid (MF-NLF) model with the local composition concept was capable of describing properties for complex systems. However, the MF-NLF model has strong temperature dependence of energy parameters and segment numbers of pure systems; thus empirical correlations as functions of temperature were represented for reliable and convenient use in engineering practices. The MF-NLF model without temperature dependence of pure parameters could not predict thermodynamic properties accurately. It was found that the present model with three parameters describes quantitatively the vapor pressure and the saturated density for the pure fluid.  相似文献   
114.
Peel strength between a copper (Cu) thin film and a polyimide (pyromellitic dianhydride-oxydianiline, or PMDA-ODA) substrate is reduced by heat treatment at 150°C in air. In this work, we investigated the peel strength, the morphology of the interface between Cu films and polyimide substrates using optical microscopy and electron microscopy, and chemical change of the interface using Auger electron spectroscopy (AES) and micro X-ray photoelectron spectroscopy (XPS). The analysis showed that CuO “lumps” were present on the peeled surface of PMDA-ODA after heat treatment at 150°C in air. The peeled surfaces of other polyimide substrates were also analyzed: biphenyl dianhydride-para phenylene diamine (BPDA-PDA) and biphenyl dianhydride-oxydianiline (BPDA-ODA). CuO lumps were present on the peeled surface of BPDA-ODA after the heat treatment, but not that of BPDA-PDA. Compared with the adhesion strength for the Cu thin film, the adhesion strength was high for the Cu/PMDA-ODA and Cu/BPDA-ODA laminates, but the adhesion strength was very low for the Cu/BPDA-PDA laminate. This low strength is the reason that CuO lumps were not detected on the peeled surface of the BPDA-PDA substrate. These CuO lumps were related to the adhesion degradation of the Cu/polyimide laminates after the heat treatment.  相似文献   
115.
A new diimide–diacid monomer, N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide (I), was prepared by azeotropic condensation of 4,4′‐oxydiphthalic anhydride (ODPA) and p‐aminobenzoic acid (p‐ABA) at a 1:2 molar ratio in a polar solvent mixed with toluene. A series of poly(amide–imide)s (PAI, IIIa–m) was synthesized from the diimide–diacid I (or I′, diacid chloride of I) and various aromatic diamines by direct polycondensation (or low temperature polycondensation) using triphenyl phosphite and pyridine as condensing agents. It was found that only IIIk–m having a meta‐structure at two terminals of the diamine could afford good quality, creasable films by solution‐casting; other PAIs III using diamine with para‐linkage at terminals were insoluble and crystalline; though IIIg–i contained the soluble group of the diamine moieties, their solvent‐cast films were brittle. In order to improve their to solubility and film quality, copoly(amide–imide)s (Co‐PAIs) based on I and mixtures of p‐ABA and aromatic diamines were synthesized. When on equimolar of p‐ABA (m = 1) was mixed, most of Co‐PAIs IV had improved solubility and high inherent viscosities in the range 0.9–1.5 dl g?1; however, their films were still brittle. With m = 3, series V was obtained, and all members exhibited high toughness. The solubility, film‐forming ability, crystallinity, and thermal properties of the resultant poly(amide–imide)s were investigated. © 2002 Society of Chemical Industry  相似文献   
116.
The equilibrium and kinetics of solvent extraction of Cu2+ from aqueous solutions containing equimolar EDTA with Aliquat 336 in n‐decanol and kerosene at 298 K were investigated. The concentrations of Cu2+ (8–50 mol m?3), Cl? (5–60 mol m?3), and Aliquat 336 (20–100 mol m?3) were varied. A semi‐empirical model with three parameters was proposed to describe the equilibrium behavior, in which the non‐idealities in both aqueous and organic phases were considered. Over the ranges studied, the model agreed reasonably well with the experimental data (standard deviation, 15%). The forward and backward reaction rate constants were determined as (5.31 ± 0.16)×10?6 m9/4 mol?3/4 s?1 and (2.62 ± 0.09)×10?7 s?1, respectively, at 298 K. An interfacial reaction mechanism was proposed, which revealed that the reaction between the chelated anions and trimeric amine molecules at the interface was rate limiting. The derived rate laws were consistent with the experimental results. © 2002 Society of Chemical Industry  相似文献   
117.
Interaction of impact shock waves that could detonate an explosive (Composition B) confined in a thin-walled container impacted by a cone-nosed projectile is numerically studied, based on the Forest Fire explosive reaction rate model. The normal impact on the container by a small projectile with a conical nose is considered. Depending on the cone angle of the nose part of the projectile, the zone of interaction of initiating shock waves can be remote from the central axis of the impact. The off-the-central-axis detonation is interpreted from the viewpoint of different interaction modes in the explosive container, which are reflected from the cassette wall, change their directions, and superimpose onto each other, leading to explosive detonation.  相似文献   
118.
Liquid-phase catalytic degradation of waste polyolefinic polymers (HDPE, LDPE, PP) over spent fluid catalytic cracking (FCC) catalyst was carried out at atmospheric pressure with a stirred semi-batch operation. The effect of experimental variables, such as catalyst amount, reaction temperature, plastic types and weight ratio of mixed plastic on the yield and accumulative amount distribution of liquid product for catalytic degradation was investigated. The initial rate of catalytic degradation of waste HDPE was linearly increased with catalyst amount (4-12 wt%), while that was exponentially increased with reaction temperature (350-430 ‡C). Spent FCC catalyst in the liquid-phase catalytic degradation of polymer was not deactivated fast. The product distribution from catalytic degradation using spent FCC catalyst strongly depended on the plastic type. The catalytic degradation of mixed plastic (HDPE: LDPE: PP: PS=3: 2: 3: 1) showed lower degradation temperature by about 20 ‡C than that of pure HDPE.  相似文献   
119.
We have discovered a series of lithium-containing oxides that immediately react with ambient carbon dioxide (CO2) up to 700°C. The products react and return reversibly to the oxides at a temperatures higher than about 700°C. The absorption capacity surpasses that of other CO2 absorbents by a factor of 10. Utilizing these absorbents, the possibility of a CO2 separation system that operates at around 500°C is proposed. It is generally believed that a CO2 separation process operable at temperatures higher than 500°C has the special benefit of a small energy penalty. Moreover, the absorption also proceeds at ambient temperature in the atmospheric environment. This property offers the possibility of many other applications, such as air cleaners or cartridges. Therefore, we think these materials have the potential to make a valuable contribution to the realization of CO2 emission control.  相似文献   
120.
Continuous solution copolymerization of methyl methacrylate with ethyl methacrylate or n-butyl methacrylate was carried out in a continuous stirred tank reactor. Solvent and initiator used were toluene and benzoyl peroxide, respectively. Reaction volume was 1.2 litters, residence time 3 hours and polymerization temperature 80°C. The copolymerization conversions were analyzed by UV spectrophotometry and confirmed by measuring the solid weights of copolymers obtained after evaporating solvent. The copolymerization of methyl methacrylate and alkyl methacrylates followed the second order kinetics. The simulated conversions and copolymerization rates were compared with the experimental results. The average time to reach dynamic steady-state was three and half times of the residence time.  相似文献   
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