Advanced Materials Research Vols. 239-242

Abstract: By using the technology of numerical reservoir simulation, we have compared superheated steam soak with saturated steam soak in area of heating, effect of distillation, capability of increasing oil production, volume of steam in need to evaluate the effect of superheated steam soak in heavy oil reservoirs. Analyzed the sensitivity of parameters like steam injection intensity, steam injection rate, soak time, degree of superheat to conclude the rule that they affect on recovery percentage. The research shows that, heating radius of superheated steam is greater than that of saturated steam, distillation effect of superheated steam is better than that of saturated steam, oil production of superheated steam is more than that of saturated steam, steam volume in need of superheated steam is less than that of saturated steam. Recovery percentage of superheated steam soak increases but more and more slowly with the increase in steam injection intensity, increases first and then decreases with the increase in steam injection rate, increases first and then decreases with the increase in soak time, increases but more and more slowly with the increase in degree of superheat. Influence of steam injection intensity is obvious to recovery percentage, but influence of other factors like soak time, steam injection rate, degree of superheat is insignificant.

Abstract: The integration process of hemihydrate calcium sulfate whiskers with optimum additives was carried out, and the influence of reagents on the crystal shape and stability of hemihydrate calcium sulfate whiskers was investigated too. The products were characterized by FT-IR, SEM and XRD.The results show that the integration of preparation and stabilization of hemihydrate calcium sulfate whiskers can be achieved with addition of 0.025% sodium stearate and 0.15% sodium oleate by adding agents in different steps.

Abstract: Effective ~1.47mm and powerful ~1.8mm infrared emissions have been observed in Tm³⁺-doped bismuth tellurite glasses with low phonon energy under the excitation of 793nm diode laser. Judd-Ofelt parameters W2 (4.65´10^-20cm²), W₄ (1.15´10^-20cm²), and W₆ (1.16´10^-20cm²) indicate a higher asymmetric and stronger covalent environment in the optical glasses. In 0.5wt% Tm³⁺-doped sample, the peak emission cross-sections of ³H₄®³F₄ and ³F₄®³H₆ transitions are derived to be 2.83´10^-21 and 6.13´10^-21cm², respectively, and the maximum gain coefficients of 0.38 and 2.21dB/cm at 1.675 (U-band edge) and 1.856mm wavelengths were anticipated in an ideal status. These results indicate the Tm³⁺-doped bismuth tellurite glasses are a promising candidate in developing S- and U-band amplifiers.

Abstract: For getting higher quality and octahedron shape product Co₃O₄, the article studies precursor baked temperature, baked temperature route, baked condition affecting on apparent density, then points out obtaining octahedron shape Co₃O₄ technology. Test shows if the practice is accorded to the technology strictly, demanding standard Co₃O₄ can be obtained.

Abstract: Homogeneous carbon nanoparticles were synthesized by chemical vapor deposition (CVD) from acetylene with zeolite as template in an atmosphere of argon. The microstructure of the products was characterized by field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The results showed that the as-synthesized products were quasi-spherical carbon nanoparticles with diameter of ca.150 nm and the interplanar distance of 0.3477 nm, and their purity was above 90%. The thermal stability of carbon nanoparticles was relatively stable. They can maintain their structure over 600°C in air or over 1000°C in argon atmosphere. In addition the formation mechanism of carbon nanoparticles was discussed briefly. Carbon source firstly filled into the template, then pyrolyzed and finally took the form of the product in consequence of template deformation.

Abstract: Zn-doped palygorskite loaded TiO₂ for visible-light active catalysts were prepared by the method of liquid ion exchange and precipitation. XRD and SEM measurments show that the titanium dioxide was loaded on the palygorskite and that composite is mainly composed of two phase,that is, the palygorskite and the nano crystalline titanium dioxide. The results show that the composite catalysts showed excellent photocatalytic ability and quantum efficient.

Abstract: Magnetic fluid as a functional material can produce volume force under external magnetic field, for the purpose of controlling the magnetic fluid flow state in the non-magnetic sealing groove with external magnetic field, the volume force is written as a function form of AZ to do with the numerical simulation of magnetic fluid flow in the sealing groove. The result shows that the magnetic fluid which distributes at the right-angle edges of the two permanent magnets nearby the separator presents unsteady swirl flow due to the volume force, while the rest magnetic fluid is in the quiescent state. It means that the magnetic fluid seal method can effectively solve the air leakage of band sintering machine and circular cooling machine.

Abstract: The flowability of W-Ni-Fe powders was evaluated through measuring the lateral pressures at different lateral distances in warm flow compacting. Green densities at different lateral distances were also tested. In addition, cross-shaped parts with threaded holes were trial produced. The results showed that, at lateral distance of 2 mm, the lateral pressure was 101.9 MPa and the green density was 9.09 g·cm^-3 when compacted under 600 MPa at 96°C. Warm flow compaction could form cross-shaped parts with lengthwise and lateral threaded holes.

Abstract: In this paper, we present a novel approach for the synthesis of carbon microspheres via the polymerization of a high internal phase emulsion (HIPE). By using Span 80 and Tween 80 as emulsifiers, 1iquid paraffin as oil phase, and the mixture of resorcinol/formaldehyde (R/F) solution as aqueous phase, an O/W emulsion was obtained. This emulsion phase inverted to a W/O HIPE induced by ammonia which served as the polymerization catalyst. Carbon microspheres (CMs) were prepared by polymerization of the HIPE, followed by drying and carbonization. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analyzer were used to characterize as-prepared CMs. The results indicate that, in case of 0.25 wt% ammonia of the HIPE, the diameters of CMs decreased from about 2 to 1 μm when the mass fraction of aqueous R/F decreased from 0.714 to 0.357; the apparent density and the specific surface areas of the CMs, however, did not change obviously, which are about 0.6 g/cm³ and 200 m²/g, respectively. The dosage of ammonia has a significant influence on the morphology and properties of CMs. With increasing of the ammonia mass to 1 wt% of the HIPE, the resultant carbon materials comprise not only CMs, but also some carbon sheets; the apparent density of which increased to 0.9 g/cm³ and the specific surface areas of which decreased to below 100 m²/g. In addition, the other parameters for CMs preparation were also investigated. It was found that the proper conditions were controlling the temperature of 303-333 K and the oil/aqueous phase mass ratio of 2.5:7.

Abstract: Rare-earth-doped compounds (Sr_1.85Ln_0.15)FeMoO₆ (Ln=Sr, La, Ce, Pr, Nd, Sm and Eu) have been prepared by solid-state reaction. Crystal structure and magnetic properties were investigated by means of X-ray diffraction and magnetic measurements. All the samples are single phase and belong to the I4/m space group. Due to the competing contributions of electron doping and steric effects, the unit-cell volume of the doped compounds changes slightly and does not vary systematically with the ionic radius of the rare-earth ions. The temperature dependence of the magnetization of (Sr_1.85Ln_0.15)FeMoO₆ indicates that the Curie temperature of the doped compounds has increased upon doping, except for the Eu-doped compound.