Advanced Materials Research Vols. 284-286

Abstract: The electronic structures of CdSe/Cd_xZn_1-xS core/shell quantum dots are investigated systematically using the effective-mass approximation method. The calculated results have shown that both of the electron and hole are completely localized at the range of core, which can be ascribed to the large energy band offset in valence band and conduction band. The carriers appear in the region of core or shell, which mainly depend on the competition between the kinetic energy and the potential energy in the heterostrucuture QDs. The transition energies can be widely tuned by the changing the structure parameters.

Abstract: In order to anticipate the color of dye ink more accurately, WENZHOU Mernuo Red-10 as an example, who was dissolved in different polarity solvent by magnetic stirring and ultrasonic agitation, the influence for properties of solvent on color of dye was researched with the coating method through contrasting sample papers. The influence for pH values of the solution and adding water to Red-10 solution on color of dye were also researched. It's shown that with the increased polarity of the solution,the absorption wavelength of Red-10 reduced gradually,light shade effect was caused. For the same solvent,with the pH values of the solvent increased,the absorption wavelength of Red-10 reduced gradually,light shade effect was caused.And all the factors affect the L,a,b values of the Red-10 dye's samples.

Abstract: The spin-dependent electronical conductivity of polarons is studied in the spin polarized organic semiconductor .It is found that the spin dependence of the electronical conductivity is induced by the spin polarization of the organic semiconductor, for the spin polarization makes the up-spin and the down-spin polarons have different density, which generates the spin-dependent electronocal conductivity. The spin-dependent electrical conductivity can be directly affected by the match level of conductivities s₀/s_f at the interface of the FM/OSE. Moreover, the current spin polarization in the organic semiconductor can be strengthened by the electric-field in the low-electric-field region .

Abstract: Response of shock initiation of cast TNT charges with double-shell casing impacted by hypervelocity fragment was studied using the non-linear dynamics software AUTODYN. The purpose of the study is to gain insight into the physical phenomena underlying debris cloud impacts, and to develop an equation that predicts critical fragment velocity at which a fragment must travel to cause initiation. First, strength model, reaction rate equation and equation of state of materials are briefly described. Second, the threshold law of shock-induced initiation of cast TNT with double-shell casings was obtained by analyzing pressure of the growth process. Final, the threshold shock initiation velocity of the fragment is calculated under different fragment diameter. Based upon above data we modified empirical Jacobs-Roslund model, which is very helpful to guide the safety study on shell charges structure.

Abstract: In the present paper, with the aid of symbolic computation, the nonlinear coupled scalar field equations relevant to materials physics are investigated by using the trigonometric function transform method. More exact traveling wave solutions are obtained for nonlinear coupled scalar field equations. The solutions obtained in this paper include four kinds of soliton solutions and four kinds of trigonometric function solutions.

Abstract: When food contamination problems occur, one of the first priorities is adsorption to any volatile or semivolatile organic chemicals in packaging materials. In this contribution the adsorption behaviour of modified polypropylene composites containing nano-silica is reported. The nano silica can increase the polarity of PP and decrease more volatile solvent residue of ethyl acetate in CPP film. If lower volatile solvent used in print ink or adhesive, load of nano silica can decrease solvent residue too, when a lesser decrease is happen in crystallinity of modified PP. The nano modification process is able to produce more safe food packaging materials, but must consider the load of nanosilica.

Abstract: The scintillation properties of Lu_1.8Y_0.2SiO₅:Ce (LYSO:Ce) and LaCl₃:Ce scintillators were studied under g-ray excitation. For 662 keV g-rays (¹³⁷Cs source), energy resolution of 4.5% obtained for LaCl₃:Ce coupled to XP5200B PMT is much better than that of 8.2% for LYSO:Ce. The estimated photofraction of 26.1% at 662 keV for LYSO:Ce is higher than that of 15.7 % for LaCl₃:Ce. The non-proportionality of the light yield and energy resolution versus g-ray energy were measured and the intrinsic resolution of the crystals was calculated. The coincidence timing resolution, obtained in this work for 511 keV annihilation quanta, was 222 and 229 ps, respectively, for LYSO:Ce – and LaCl₃:Ce – based detectors in coincidence with a BaF₂ detector.

Abstract: A method for evaluating the photolysis behavior of photoacid generator in solvent and high polymer film has been established through spectrophotometry and fluorospectrophotometry by using the acid-sensitive Rhodamine B as tracer. Results showed that this method is feasible and practicable for evaluating the acid generating efficiency of photoacid generator in organic solvents or polymer film, yielding quantitatively precise data of the photochemical reaction and acid generating behavior, thus is very useful for evaluating the quality of different types of photacid generators e.g. triazines, sulfonium salts etc.

Abstract: Alkyd resin dispersions are used in the paint industry as the basis for the new generation of environmentally friendly gloss paints. This research based on two-component seed oil soybean oil and castor oil to synthesis high-efficiency modified alkyd resin. The experimental conditions are the mass ratio of soybean oil with castor oil is 2:1, 55% degree of oil, Ni(OH)2 as the catalyst and 210°C~220°C for alcohol solution reaction, 220°C for esterification under the protection of nitrogen. The experimental results show that the product non-drying days are more than 30 days, acid value is 6.6, the migration is 1.2%, adhesion is one level, flexibility is 0.5, chroma value is 8.

Abstract: The CaTiO₃ compounds were prepared by sintering the mixtures of the TiO₂ and CaO in air. The compounds were used as cathode, the graphite as anode and the molten CaCl₂-NaCl as electrolyte. Electrolysis was performed at 800°C and constant-voltage 3.2V in dry argon atmosphere. The results showed that the electrolytic rate could be significantly enhanced because of the additive CaO. The electrolysis time was shortened efficiently than that of direct electrochemical reduction of solid TiO₂.