Temperature-Dependent Optical Reflectivity of Tetragonal-Prime Yttria-Stabilized Zirconia

The optical reflectance of dense, metastable, tetragonal-prime zirconia plates, made by densifying electron beam physical vapor-deposited powder, is reported as a function of temperature up to 1673 K (1400°C) over the range of 400–1500 cm⁻¹ (6.67–25 μm). Curve fitting of the reflectance as a function of temperature was performed using two different damped oscillator models, each with three infrared (IR)-active modes. Oscillator parameters were then used to calculate the values of the indices of refraction and absorption as a function of temperature using the classical dispersion theory. The reflectance data of tetragonal-prime yttria-stabilized zirconia at room temperature are qualitatively similar to that reported for the equilibrium tetragonal phase in that it can be fit with three IR-active modes.     

Control of molecular packing structure of a derivative of vanadyl-phthalocyanine using pore wall of porous alumina and/or magnetic field

We filled one-dimensional alumina pores with a molten derivative of vanadyl-phthalocyanine (VOPcHt) and evaluated the effect of the surface of pore wall on the molecular packing structure of VOPcHt. We also evaluated the effect of a magnetic field of 5.0 T on the packing structure of VOPcHt that was solidified on a flat substrate. X-ray diffraction measurements revealed that both the surface effect as well as the magnetic field controlled the packing structure of VOPcHt. When both the pore wall and the magnetic field existed, the surface effect was dominant in the control of the packing structure. These results provide practical methods to fabricate nanostructures of organic molecules with a controlled molecular packing structure.     

Self-calibration of precision angle sensor and polygon mirror

The present paper describes a high-precision angle sensor and a new method for calibrating precision angle sensors absolutely without the use of any accurate reference instruments. Two angle sensors with compensating devices which compensate thermal drift of the light source are developed and calibrated by themselves. The repeatability error of the evaluated mean sensitivity was improved to 0.01% by the compensating device. The repeatability of the calibrated linearity error was reduced to 0.025 s (arc). This paper also describes a new differential method that can calibrate simultaneously the dividing errors of a polygon mirror and angular profile of polygonal surfaces by using the developed angle sensors. Calibration of a 24-sided polygon mirror showed the repeatability error of dividing angle and angular profile to be approximately 0.2 s (arc).     

Photocatalytic effect of ZnO on carbon gasification with CO2 for high temperature solar thermochemistry

A photocatalytic effect of ZnO on carbon gasification with CO₂ was studied using a concentrated Xe beam to enhance the gasification rate in solar/chemical energy conversion process. The sample, activated carbon impregnated with ZnO (5 wt%), was heated at 873 K by a Xe beam irradiation with UV (<400 nm). The gasification rate at 873 K increased 2 folds in comparison with the Xe irradiation without UV, but, the difference of the rate of CO evolution decreased with the increasing temperature from 873 to 1073 K. The carbothermal reduction of ZnO (ZnO+C→Zn+CO) proceeded at above 950 K, which was demonstrated by XRD analysis and thermodynamic calculation. These results indicate that the photocatalytic effect of ZnO with the UV irradiation enhance the gasification rate of carbon at low temperature (873 K).     

直喷汽油(DIG)汽车发动机无声链条系统用温压-高温烧结粉末冶金链轮的开发

作者们以前报导过非直喷汽油 (一般MPI汽油 )发动机滚子链条系统用温压 -常规温度 ( 114 0℃ )烧结的粉末冶金链轮。在这个新开发的项目中 ,研究了几种温压 -高温烧结的粉末冶金钢的力学性能。为测定这些材料的耐磨性 ,用虚拟发动机进行了磨耗试验。最终开发出了可承受严酷磨耗条件的DIG发动机无声链条系统的链轮。使用的基础粉末是混合粉 (DistaloyDC1)。其含 2 %Ni(质量分数 ) ,Ni粉是通过扩散粘结在Fe - 1 5 %Mo(质量分数 )粉末颗粒上的 ,温压是在 130℃下 ,用这种粉末、阴模及模具进行的。烧结温度为 1190℃。链轮还进行了热处理     

Studies on the direct liquefaction of protein-contained biomass: The distribution of nitrogen in the products

In studies of the direct aqueous liquefaction of protein-contained biomass such as sewage sludge, nitrogen derived from proteins is distributed in both the oil and aqueous phases. The nitrogen in the oil is very difficult to remove by hydrotreatment over nickel/molybdenum catalysts. Egg albumin was used as a model protein in direct liquefaction studies of the nitrogen distribution in the products. The oil yield from albumin (10%) was much less than that obtained from actual feedstocks (typically in the range 30–40%). The nitrogen content of the oil (9%) represented less than 5% of the total nitrogen, while in the liquefaction of actual feedstocks, 30–50% of the nitrogen in the feedstock was found in the oil. No distribution of nitrogen to oil under 150°C occurred because of no oil yield. The majority of the nitrogen in albumin (80%) was distributed to the aqueous phase above 200°C. The distribution of nitrogen to oil was completed by 250°C. Sodium carbonate, used as a catalyst, prevented the distribution of nitrogen to oil. Albumin was decomposed to ammonia, not to amino acids.     

On-line inference of tube-wall temperature in an industrial olefin pyrolysis plant

A major difficulty in the efficient functioning of industrial pyrolysis is the lack of suitable on-line tube-wall temperature measurements. In this paper, an inferential scheme is developed to predict the tube-wall temperature, which is called skin temperature, in an industrial olefin pyrolysis plant. Based on a theoretically-derived model, the skin temperature is predicted from the available on-line measured process variables, such as gas temperature around the tube, fuel gas flowrate, and naphtha feed flowrate. Using the infrequently off-line measured skin temperature with the on-line measurements, adjustable parameters of the model are updated on-line according to the Kalman filter technique. The application of this scheme then is illustrated using operating data obtained from an industrial olefin pyrolysis plant. The results of the proposed scheme show that, by taking infrequent measurements of the skin temperature for model adaptation, the skin temperature can be predicted successfully for every tube in the pyrolysis over an extended time interval. Simulations suggest that as few as one or two manual measurements of the skin temperature, taken during the entire cracking operation, provide sufficient information to maintain the developed inferential system at a practical level.     

Microscopic magnetism in lithium insertion materials of LiNi1−xCoxO2 (x = 0, 1/4, 1/2, 3/4, and 1)

The magnetic nature of lithium insertion materials of LiNi_1−xCo_xO₂ (x = 0, 1/4, 1/2, 3/4, and 1) were investigated by means of positive muon-spin rotation/relaxation (μ⁺SR) spectroscopy combined with X-ray diffraction (XRD) analyses and susceptibility measurements. Zero field μ⁺SR spectra for all the samples below 300 K were well fitted by a dynamic Kubo–Toyabe function, indicating the existence of randomly oriented magnetic moments even at 2 K, i.e., disordered state. The field distribution width Δ due to magnetic Ni³⁺ ions decreases exponentially with increasing x, suggesting that the Co substitution is likely to simply dilute Ni moments. This also supports that cobalt and nickel ions are homogeneously distributed in a solid matrix even in a muon-scale (microscopically), which is consistent with the results of macroscopic measurements.     

Bandgap-tunable lateral and vertical heterostructures based on monolayer Mo<Subscript>1-<Emphasis Type="Italic">x</Emphasis></Subscript>W<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>S<Subscript>2</Subscript> alloys

The fabrication of heterostructures of two-dimensional semiconductors with specific bandgaps is an important approach to realizing the full potential of these materials in electronic and optoelectronic devices. Several groups have recently reported the direct growth of lateral and vertical heterostructures based on monolayers of typical semiconducting transition metal dichalcogenides (TMDCs) such as WSe₂, MoSe₂, WS₂, and MoS₂. Here, we demonstrate the single-step direct growth of lateral and vertical heterostructures based on bandgap-tunable Mo_1-x W _x S₂ alloy monolayers by the sulfurization of patterned thin films of WO₃ and MoO₃. These patterned films are capable of generating a wide variety of concentration gradients by the diffusion of transition metals during the crystal growth phase. Under high temperatures, this leads to the formation of monolayer crystals of Mo_1-x W _x S₂ alloys with various compositions and bandgaps, depending on the positions of the crystals on the substrates. Heterostructures of these alloys are obtained through stepwise changes in the ratio of W/Mo within a single domain during low-temperature growth. The stabilization of the monolayer Mo_1-x W _x S₂ alloys, which often degrade even under gentle conditions, was accomplished by coating the alloys with other monolayers. The present findings demonstrate an efficient means of both studying and optimizing the optical and electrical properties of TMDC-based heterostructures to allow use of the materials in future device applications.

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Liquid‐Filled Valence Tautomeric Microcapsules: A Solid Material with Solution‐Like Behavior

The integration of stimuli‐responsive valence tautomeric (VT) molecular systems into solid materials without compromising their functionality is a major bottleneck for the use of these compounds in high‐added value applications. In this work, an innovative, simple, and universal approach is described to tackle this challenge based on the confinement of the active species into liquid‐filled polymeric capsules. A microstructured solid with optimized solution‐like behavior is obtained in this way, whose VT properties can be rationally tuned upon variation of the encapsulated solvent. Incorporation of the resulting capsules into thin films or other matrices of interest allows successful transfer of valence tautomerism from the liquid phase to solid materials, thus paving the way to the fabrication of functional devices based on spin transition compounds.