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This research used a two-stage fluidized-bed gasifier to investigate the effects of the temperature, equivalence ratio, and steam/biomass ratio on the syngas composition. When the operating temperature in the first stage increased from 700 °C to 900 °C, the proportion of H 2 in the syngas increased significantly. After passing through the second stage (900 °C), the syngas produced from the first stage underwent the thermal reaction again, and the proportion of H 2 was further increased. When the ER value increased from 0.2 to 0.3, the proportion of H 2 in the syngas increased; whereas, when the ER value increased to 0.4, the amount of H 2 produced was reduced. For S/B ratio, an increase to 0.5 enhanced the steam content of the gasifier and accelerated the methane–steam reforming reaction, thus producing more H 2 (up to 52 mol%). Furthermore, when the operating temperature of the fluidized bed reactor at the second stage was set at 900 °C, the proportion of H 2 in the syngas could still be effectively improved to more than 42 mol% although the operating temperature at the first stage was only 700 °C. The proportion of H 2 was enhanced to more than 52 mol% with a combination of appropriate ER and S/B ratio values. [ABSTRACT FROM AUTHOR]

Micro-honeycomb barium titanate (BaTiO 3 ) ceramics, which have uniformly distributed one-dimensional pore channels, were prepared by freeze-casting suspensions of hydrothermally synthesized BaTiO 3 nanopowder with a particle size of 100 nm. The effects of sintering schedules such as sintering temperature and holding time on pore size distribution, porosity, pore wall density and grain size were studied. The grain size on the pore wall of BaTiO 3 is around 1–2 μm after two-step sintering. The crystallographic structure of all samples was tetragonal phase regardless of the sintering schedules. Ferroelectric domains were shaped in a stripe and the domain width obviously increased after polarization. The micro-honeycomb BaTiO 3 sintered at lower temperature or shorter holding time showed larger piezoelectric coefficient d 33 and smaller dielectric constant ε r . [ABSTRACT FROM AUTHOR]

We study the BCS–Bose Einstein Condensation (BEC) crossover of a three-dimensional spin polarized Fermi gas with Rashba spin–orbital coupling (SOC). At finite temperature, the effects of non-condensed pairs due to the thermal excitation are considered based on the G 0 G pair fluctuation theory. These fluctuations generate a pseudogap even persistent above T c . Within this framework, the Sarma state or the spin polarized superfluid state and polarized pseudogap state are explored in detail. The resulting T c curves show that the enhancement of pairing due to the SOC roughly cancels out the suppression of pairing due to the population imbalance. Thus we observed that in a large portion of the parameter space, the polarized superfluid state are stabilized by the SOC. [ABSTRACT FROM AUTHOR]

A novel, mild, inexpensive, nontoxic, and effective, one-pot synthesis of vicinal diamines with benzaldehyde and aniline derivatives mediated by 10% of BiCl 3 and 3 equiv of Zn in ethanol at reflux temperature has been developed and systematically investigated. A wide range of substituted vicinal diamines compounds were obtained in good to excellent yields. The scope and limitations of this reaction have been examined. Steric and electronic effects of reactants have been discussed. [ABSTRACT FROM AUTHOR]

Porous YSZ ceramics were prepared by a gel-casting method using tert-butyl alcohol (TBA) as solvent and Al2O3 fiber as reinforcement. Effects of sintering temperature, soaking time and Al2O3 fiber content on porosity, microstructure, compressive strength, and fracture toughness of the porous ceramics were studied. Compressive strength of porous YSZ ceramics was improved while the porosity decreased with the increase of sintering temperature and soaking time. Addition of Al2O3 fibers significantly strengthened and toughened porous YSZ ceramics; however, the laws of strengthening and toughening were different. The strength of the porous YSZ ceramics reached maximum at the addition of 10vol% Al2O3 fibers, and the corresponding compressive strength and flexural strength were 100.2±25.4MPa and 61.5±11.3MPa, respectively. Fracture toughness of the porous YSZ ceramics monotonically increased with increasing of Al2O3 fibers, and could be improved from 0.5MPam1/2 to 1.2MPam1/2 (improved by 140%). The strengthening and toughening mechanisms of Al2O3 fibers were discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] We synthesize mesoporous zirconia with different amounts of aluminum doping. [•] Doping of zirconia with aluminum stabilizes tetragonal zirconia. [•] Increasing aluminum content will increase the crystallization temperature. [•] Increasing aluminum content will improve the thermal stability. [•] The mesoporous zirconia with Al/Zr of 1 possess highest thermal stability. [Copyright &y& Elsevier]

Abstract: This work presents an experimental investigation of the friction and heat transfer characteristics in a narrow rectangular channel. Nine groups of experiments are conducted and the fluid temperature difference between the inlet and outlet of the test section is kept constant in each experimental run. The results show that the friction factors in isothermal condition can be well correlated by the Leon correlation for the developed laminar and turbulent flow, and the Bhatti and Shah correlation for the laminar to turbulent transition region. In addition, the friction factors prediction correlations in non-isothermal condition are proposed based on the viscosity ratio method. The heat transfer characteristic is not affected by the change of temperature difference in laminar flow. However, as in the fully developed turbulent flow, the Prandtl number significantly influences the heat transfer characteristic. The heat transfer temperature difference between the wall and fluid increases with the increase of Reynolds number in the laminar flow, and decreases sharply as the flow enters the transition region. However, it does not present a significant variation in the fully developed turbulent flow regime. Based on the analysis of heat transfer temperature difference, a new correlation for calculating the Nusselt number in the turbulent flow regime of a rectangular channel is introduced and the agreement between experimental data and predicted values is satisfactory. [Copyright &y& Elsevier]

This study shows that C can degrade pBR322 plasmid DNA at room temperature without photoactivation. The degradation was enhanced by increasing incubation temperature, reaction time or C concentration. We also found that superoxide radical anions (O) were formed in the C solution. Superoxide dismutase significantly inhibited DNA cleavage and O generation induced by C. These results suggest that DNA cleavage was caused by the formation of reactive oxygen species induced by C at room temperature. Furthermore, we demonstrate that the DNA degradation was significantly inhibited by acid amide chemicals such as formamide, and by increased ionic strength of the reaction solution. These results indicate that the DNA conformation stability and the surface properties of C are important factors regulating DNA degradation. We propose that C can bind DNA, decrease DNA conformation stability, and induce the formation of reactive oxygen species and DNA cleavage at room temperature. Our results provide a possible explanation for the genotoxicity of C, which should be considered in future use of this particular nano-material. [ABSTRACT FROM AUTHOR]

Abstract: Porous yttria-stabilized zirconia (YSZ) ceramics with unidirectionally aligned pore channels were prepared by freezing YSZ/tert-butyl alcohol (TBA) slurry under different freezing temperatures of −30, −78 and −196°C, respectively. After removing the frozen TBA via freeze-drying in vacuum at −50°C, the green samples were sintered at 1450°C for 2h in air. The results showed that the freezing temperature significantly influenced microstructure and properties of the porous YSZ ceramics. Both microstructure observation and pore size distribution indicated that the pore channel size decreased significantly with decreasing freezing temperature, regardless of microstructure variations in the individual sample. Both porosity and room-temperature thermal conductivity of the porous YSZ ceramics varied under different freezing temperatures. Regardless of microstructure variations in the samples under different freezing temperatures, all samples had unidirectional pore channels with increasing pore channel size along the freezing direction. The fabricated samples had remarkably low thermal conductivities both in directions perpendicular and parallel to the channel direction, thus rendering them suitable for applications in thermal insulations. [Copyright &y& Elsevier]

Abstract: Porous yttria-stabilized zirconia (YSZ) ceramics were fabricated by tert-butyl alcohol (TBA)-based gel-casting method for potential applications in heat-insulation materials. The effect of sintering temperature on compressive strength of porous YSZ ceramics was investigated on the basis of measurements linear shrinkage, porosity and pore size. As the sintering temperature increased from 1350 to 1550°C, a decrease of porosity from 77 to 65%, a decrease of average pore size from and an increase of linear shrinkage from 15.4 to 31.8% were observed. The compressive strength increased remarkably from 3 to 27MPa with increasing sintering temperature from 1350 to 1550°C, which was related to the corresponding change of linear shrinkage, porosity, pore size and microstructure. A remarkable decrease of compressive strength with increasing porosity was observed. The compressive strength decreased also with increasing pore size. [Copyright &y& Elsevier]

Abstract: Silver nanoparticles and nanoplates were prepared at the air/AgNO3 aqueous solution interfaces under poly(9-vinylcarbazole) (PVK) monolayers when illuminated by UV-light at room temperature and elevated temperatures, respectively. When the illuminated films at the air/water interfaces were covered by carbon-coated copper grids, nanoplates were formed even at room temperature, and the size of the nanoplates was much larger than those formed at the air/water interface under the same experimental conditions, indicating that copper took part in the formation of Ag nanoplates through the galvanic displacement reaction between Cu and Ag+ ions with the help of carbon layer to conduct electrons. It was found that the basal plane of these nanoplates is the (111) face of a face-centered cubic (fcc) Ag crystal. Although platelike structure can be formed at the carbon-coated copper grid/AgNO3 aqueous solution interface without PVK film, it shows different features from those with PVK films, indicating that PVK film plays an important role in the formation of regular large nanoplates. Further observations indicate that special restrained microenvironment, adsorption of PVK molecules on a specific crystal face, anisotropic growth and attachment of the nanoparticles are responsible for the formation of the nanoplates. [Copyright &y& Elsevier]

A modfied polyisobutylene succinimide T154) asphaltene dispersant was prepared by modifying PIBSA with hexyl hexanol, and was applied to the preparation of FCC slurry scale inhibitor. The effects of modification temperature, modification time and material mass ratio on asphaltene dispersion and scale inhibitor on FCC slurry were investigated. The results showed that when the modification temperature was 240 °C, the modification time was 4 h,and the mass ratio of polyisobutylene succinimide m) to hexyl hexanol m) was 1u 1,the dispersion performance was better than polyisobutylene succinimide. The product had exceHent thermal stability; when the dosage of scale inhibitor was 150 g/g, the scale inhibition rate was 91.3. [ABSTRACT FROM AUTHOR]

Abstract: The garnet-related oxide with nominal formula Li7La3Zr2O12 prepared by the sol–gel method is cubic, space group Ia-3d with lattice parameter a =12.9720Å at room temperature. The occupancies of three lithium positions (24d, 48g, 96h) and the position of a small amount of Al3+ (ca 0.61wt%) inside the grains were determined by neutron diffraction. The occupancy of the 24d Li sites was reduced to 36.0% by the Al3+ occupying the 48g sites. The bulk and total Li+-ion conductivity at 25°C was 3.1×10−4 Scm−1 and 1.4×10−4 Scm−1 with an activation energy 0.34eV in the temperature range 25–160°C. [Copyright &y& Elsevier]

Abstract: ZnO films were prepared by pulsed laser deposition (PLD) on glass substrate with temperature ranging from room temperature (RT) to 500°C. All the films formed the hexagonal wurtzite structure and showed the c-axis (002) preferred orientation. The films deposited at 200°C showed the narrowest full width at half maximum of both X-ray diffraction (XRD) and rocking curve, largest height grain size, smallest macrostress and least point defects. Meanwhile, it was found that the films deposited at 350°C displayed the most intense diffraction peak in XRD and a strong UV emission while it showed the most intense defect-related green emission, fastest growth rate and larger macrostress. In addition, the cross section images showed all films grew with a columnar form along (002) orientation. [Copyright &y& Elsevier]

Boron carbide submicron powder was synthesized with boron oxide and graphene as starting materials by gas-solid reaction method using two different apparatuses. The effects of calcination temperature and holding time, apparatus type and B 2 O 3 /C ratio of the starting materials on the phase composition and morphology of the synthesized powders were evaluated. A newly formed residual carbon morphology distinct from original graphene were present in samples synthesized at a higher B 2 O 3 /C ratio or temperature. The synthesis temperature of ∼1500 °C was found to be more suitable to obtain boron carbide powder without the existence of residual carbon. The new type of apparatus enabled the synthesis of boron carbide phase at a relatively lower temperature, due to its more efficient use of B 2 O 3 vapor. [ABSTRACT FROM AUTHOR]

Pure anorthite porous ceramics have been fabricated using γ-Al2O3, CaCO3, and SiO2 as raw materials through foam-gelcasting method. XRD, thermal analysis, SEM, and TEM were used to study the synthesis and grain growth of anorthite during the in situ process. The results indicated that the initiator (ammonium presulfate) took part in the chemical reaction to form CaSO4, which played an effective role during synthesis of anorthite. Besides, CaO and CaSiO2 were the other intermediate phase during synthesis. Anorthite first occurred at 1050°C, and it was the only phase after it sintered over 1260°C. With sintering temperature increasing from 1300°C to 1450°C, the large sphere pore wall got denser and the anorthite grains obviously showed platelike. It was deduced that the preferential growth of anorthite crystals was parallel to the (004) plane. [ABSTRACT FROM AUTHOR]

The garnet-type solid Li-ion conductor, Li6.4La3Zr1.4Ta0.6O12, is viewed as a promising solid-state electrolyte for the next-generation high-performance Li-ion battery because of its high ionic conductivity and stability. The previous researches, in order to avoid Li volatilization loss during solid-state reaction of sintering, mother powder with the same composition as green bodies was usually used to cover the samples, it would waste the expensive raw materials and increase the fabrication cost. In this study, a new method was proposed to prepare the Li6.4La3Zr1.4Ta0.6O12 ceramic solid-state electrolyte where the Li loss is compensated by the outside Li2CO3. Samples prepared by this method have pure garnet phase and compact micromorphology with few pores. These samples have a high Li-ion conductivity of 2.9×10−4 S/cm and a low activation energy of 0.37 eV at room temperature. The electronic conductivity is 1.08×10−8 S/cm, which can be neglected for solid-state electrolyte. [ABSTRACT FROM AUTHOR]

Cubic perovskite–type oxide Li 3/8 Sr 7/16 Hf 1/4 Ta 3/4 O 3 (LSHT) is a promising solid electrolyte material for next–generation Li–ion batteries such as all–solid–state Li batteries and Li–redox flow batteries due to its high room–temperature Li–ion conductivity and good chemical compatibility with commercial organic liquid electrolyte. High relative density is another important requirement for these applications. Here we investigate the influence of sintering additives (Li 3 BO 3 , Li 4 SiO 4 , LiF) on the density, the total Li–ion conductivity, the interfacial conductivity against commercial liquid electrolyte, and the cycling performance of the hybrid Li-ion cells. The results show that comparing with other additives, LSHT sintered with 2 wt% LiF shows the highest Li–ion conductivity (3.3 × 10 −4 S cm −1 ) and the smallest interfacial resistance (125 Ω cm 2 ) against organic electrolyte at room temperature; Li/LiFePO 4 batteries with LSHT pellets fired with 2 wt% LiF have the best cyclability and the highest coulombic efficiency (99.6 ± 0.04%) in 50 cycles. [ABSTRACT FROM AUTHOR]

Abstract: Formation and reservoir of steam injection well thermal properties are important parameters for evaluating thermal efficiency of thermal recovery process. Oil saturation of reservoir is also a crucial criterion for evaluating exploitation value of oil field. This study firstly presents a layered inversion method for estimating the spatial distributions of formation and reservoir thermal properties from temperature logs, and then the distribution of oil saturation in reservoir is predicted by a semi-empirical oil saturation model with the inversion thermal properties distributions. The proposed method was based on the heat transfer in steam injection well. Sensitivity analysis was firstly conducted to investigate the sensitivity of uncertain parameters, determining the inversion sequence. Then the spatial distributions of thermal properties were obtained by the layered inversion method, which reflected the diversity in physical properties of different wells and depth variability. Consequently, the present method not only could estimate effectively the thermal properties distributions which showed variability over the whole spread in depth; but also was able to predict reservoir depth by the significant change in thermal properties distributions between formation and reservoir. Above all, the estimated oil saturation distribution agreed well with the field data with relative error below 10%. [Copyright &y& Elsevier]

The NASICON oxides with general formula Li1+x Y x Zr2−x (PO4)3 (0.1 ≤ x ≤ 0.2) are prepared by conventional solid-state reaction. The samples are characterized by XRD, SEM, electrochemical impedance spectroscopy and 7Li MAS NMR measurements. The structures are refined by the Rietveld method from powder X-ray diffraction data. With the introduction of Y3+, the volume of the large M1 cavity is reduced and the rhombohedral NASICON phase is stabilized at room temperature. The bulk and total Li+ conductivities of Li1.15Y0.15Zr1.85(PO4)3 sintered by SPS are 1.4 × 10−4 and 0.71 × 10−4 S cm−1 at 25 °C, respectively; the activation energy is about 0.39 eV in the temperature range 300–473 K. [ABSTRACT FROM AUTHOR]

Abstract: Oil reservoir thermal properties not only play an important role in steam injection well heat transfer, but also are the basic parameters for evaluating the oil saturation in reservoir. In this study, for estimating reservoir thermal properties, a novel heat and mass transfer model of steam injection well was established at first, this model made full analysis on the wellbore-reservoir heat and mass transfer as well as the wellbore-formation, and the simulated results by the model were quite consistent with the log data. Then this study presented an effective inversion method for estimating the reservoir thermal properties through temperature log data. This method is based on the heat transfer model in steam injection wells, and can be used to predict the thermal properties as a stochastic approximation method. The inversion method was applied to estimate the reservoir thermal properties of two steam injection wells, it was found that the relative error of thermal conductivity for the two wells were 2.9% and 6.5%, and the relative error of volumetric specific heat capacity were 6.7% and 7.0%,which demonstrated the feasibility of the proposed method for estimating the reservoir thermal properties. [Copyright &y& Elsevier]

Abstract: In this paper, porous mullite/corundum ceramics with high porosity, high strength and low thermal conductivity were fabricated by foam-gelcasting method using fused mullite powder as raw material. Effects of sintering temperature on linear shrinkage, bulk density, apparent porosity, compressive strength and thermal conductivity of the porous mullite/corundum ceramics were researched. As sintering temperature increased from 1350 to 1550°C, linear shrinkage increased from 2.6 to 9.5%, porosity decreased from 81 to 78%, bulk density increased from 0.59 to 0.69g/cm3, compressive strength increased from 3.1 to 11.7MPa and thermal conductivity increased from 0.14 to 0.35W/m·K. Porous microstructure was complex, where large spherical pores contained small cellular pores on their internal walls. [Copyright &y& Elsevier]

Abstract: The activity coefficients at infinite dilution, , for both polar and non-polar solutes in the ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate [EMIM][TCB] have been determined by gas–liquid chromatography at the temperatures from (303 to 343)K. The partial molar excess enthalpies at infinite dilution of the solutes in the ionic liquid were also calculated from the temperature dependence of the values. The selectivity for the hexane/benzene and cyclohexane/benzene separation problems was calculated from experimental infinite dilution activity coefficient values and compared to the other ionic liquids, taken from the recent literature. [Copyright &y& Elsevier]