Advanced Materials Research Vols. 608-609

Abstract: For a transmission system, there is always required a light detector with high access speed and high sensitivity. The silicon light detector will achieve those requirements under the consideration of cost and reliability. Generally, the surface of this device will be covered by a passivation layer to protect from external damage or wet erosion. As for a light detector, the passivation layer must possess the anti-reflect ability to increase the absorption of light. In this paper, we have taken the P-I-N silicon photodiode as the main part and compared the difference light absorption for different passivation-material layers. Eventually, according to the experimental results, the optimized thin film structure can increase about 17.94% light response.

Abstract: It is feasible to obtain low temperature that can liquefy the natural gas using supersonic separator in a liquefaction process. This paper represented a design method of the supersonic separator used in natural gas liquefaction plant, including the design of the Laval nozzle, the design of the rectifier straight segment and the design of the diffuser segment. The size of each part and the appropriate shape can be gotten by the theoretical calculation. The design results of an experiment liquefaction device using supersonic separator is given. The work is helpful for the natural gas transportation in remote and low production gas field.

Abstract: The electrical properties of evaporated ZnTe films were investigated with emphasis on the effects of an annealing temperature from 600oC to 800oC by RTA technique. Crystallinity, carrier concentration, sheet resistance, and mobility are shown to be dependent on the annealing temperature. The highest carrier concentration and lowest sheet resistance are 7.9×10¹⁵ cm^-3 and 9300 Ω/□ at an annealing temperature of 700oC, respectively. The mobility was found to vary from 20 to 50 cm²V^-1S^-1. The ZnTe thin films using thermal evaporation can find applications in solar cell or light emitting diodes

Abstract: Graphene has unique structure and excellent performance , It has good optical, thermal, mechanical properties and electrical conductivity. In this article , based on elaborating the structure , characteristic and preparation methods of the graphene , the modification of graphene in polymer composite was discussed and the development and research direction of the graphene/polymer composite were proposed. The conductivity of poly (3,4-ethylenedioxythiophene) (PEDOT) doped with poly(4-styrenesulfonate) (PSS) blended with different ratios of graphene/PVDF (polyvinylidiene fluoride) solution was measured. After dryness, we found that an addition of graphene/PVDF solution lowered the resistance by three or four orders of magnitude when the concentration are 25wt% and 50wt% , among them the Gb50 has the best surface conductivity, the magnitude is about 1.43 S/cm, and then we found that the second onset degradation temperature of PEDOT/PSS membrane blended with graphene/PVDF was 75°C higher than that of without blended with graphene/PVDF. All kind of dispersion has been studied using a four-point probe conductive meter, X-ray diffractometry (XRD), fourier transform infrared (FTIR), thermogravimetric analysis(TGA) and scanning electrical microscopy (SEM) in order to discuss the surface resistance, the crystallinity, the chemical structure , the thermal properties and morphology of the PEDOT/PSS-graphene/PVDF film. Conductive PEDOT/PSS-graphene/PVDF membrane has good electrical properties and thermal stability , which can be used for the electrolyte of lithium battery.

Abstract: Silicon and related materials have recently received considerable attention as potential anodes in Li-ion batteries for their high theoretical specific capacities. To overcome the problem of volume change , composites comprising porous silicon, disordered carbon (DC) have been prepared by pyrolyzing the critic acid. This composite anode material showed a discharge capacity of 1390 mAh/g in the first cycle, and the initial columbic efficiency is 70%. After 20 cycles, the discharge capacity of the material is 511 mAh/g. The improved stability of this material is hypothesized to depend on the unique structure of porous Si and the coated DC. The morphologies of the composites were systematically investigated by the X-ray diffraction and scanning electron microscopy. It can be observed that porous Si particles were embedded into the matrix of the DC. The capacity and cycling stability of the composites were systematically evaluated by electrochemical charge/discharge tests.

Abstract: This article by palladium deuterium gas-solid experimental system design, combined with the DH1716A program-controlled DC stabilized current supply and Keithley 2700 data acquisition and recording system. In five different pressure, through current and 1.5A trigger condition, making experiments of deuterated Palladium chemical reactions within the system, resulting in dozens of Watts of thermal power, and repeat for the six-sixths.

Abstract: Silicalite-1 membranes were successfully synthesized on α-Al₂O₃ tubes by in-situ hydrothermal synthesis after filling the tubes with water and glycerol mixtures, and all the membranes show high concentration performance towards ethanol/water mixtures after pretreating tubes with different NaOH solution. The results show that the flux enhances with the enhancement of NaOH solution concentration, but the separation selectivity decreases with the enhancement of NaOH solution concentration. After pretreating the α-Al₂O₃ tubes with different NaOH solution, the weight of all the α-Al₂O₃ tube decreases, but the Si/Al ratio increases, which shows that suitable pretreatment of α-Al₂O₃ is useful for improving the hydrophobicity of silicalite-1 membranes.

Abstract: The facters of molar ratio of aniline and ammonium persulfate ,aniline concentration, concentration of HCl , carbon species and different additives was studied on the yield and conductivity of polyaniline, also the coulomb efficiency and the cycle life of Zinc-PANi secondary battery. Results show that: the molar ratio of aniline and ammonium persulfate is 1:0.9, aniline concentration 0.12mol/L and the wooden actived carbon is 35% of the weight of aniline, the best value of conductivity and capacity are respectively 2.27S/cm and 121.5mAh/g.

Abstract: The Ni was partially substituted by M (M=Co, Cu) in order to ameliorate the hydriding and dehydriding kinetics of Mg2Ni-type alloy. The melt spinning technology was used to prepare the Mg20Ni10-xMx (M=Mn, Cu; x=0, 1, 2, 3, 4) alloys. The structures of the as-spun alloys were characterized by XRD and TEM. The hydriding and dehydriding kinetics of the alloys were measured by an automatically controlled Sieverts apparatus. The results show that the as-spun (M=Mn) alloys hold a nanocrystalline and amorphous structure, whereas the as-spun (M=Cu) alloys display an entire nanocrystalline structure, indicating that the substitution of Mn for Ni facilitates the glass formation in the Mg2Ni-type alloy. Additionally, Mn substitution incurs the formation of secondary phases MnNi and Mg instead of changing the Mg2Ni major phase. The hydriding kinetics of the as-spun alloys first mounts up and then declines with the rising of M (M= Mn, Cu) content, whereas the substitution of M (M=Mn, Cu) for Ni enhances the dehydriding kinetics of the alloy dramatically.

Abstract: In order to improve the practical performance of common Cellophane as packaging material, PET/PT composite film were prepared by means of Dry Lamination, and the influence of temperature on water vapor permeation of composite films was investigated at the range of 20-50°C at 50% relative humidity. The results showed that the moisture barrier properties of common Cellophane were improved obviously by means of coating on the PET films and the water vapor transmission rate of composite films was increased with temperature increasing in the range from 20°C to 50°C，the relationship between water vapor transmission rate of the composite films and the temperature followed an exponential grow curve [y=1.3441exp (0.0597x)], correlation coefficient R is 0.9957.