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961.
Facile growth of 1‐D nanowire‐based WO3 thin films with enhanced photoelectrochemical performance 下载免费PDF全文
A flame reactor embedded with a constant tungsten wire feeding system to prepare one‐dimensional (1‐D) nanostructured tungsten oxide thin film for photoelectrochemical (PEC) water splitting was developed. Photoactive vertically‐aligned nanowire‐based WO3 thin films could be obtained with a controlled thickness via a flame vapor deposition process followed by air‐annealing. The PEC performances of WO3 photoelectrodes for different thin film thicknesses were examined. The optimum thickness of WO3 thin film was found to be about 7.2 μm for PEC water splitting based on incident photon‐to‐current efficiency plots and I–V curves. The WO3 prepared with optimum thickness showed better PEC performance than those of recently reported nanostructured WO3 photoanodes. © 2015 American Institute of Chemical Engineers AIChE J, 62: 421–428, 2016 相似文献
962.
Mathematical simulation of wet spinning coagulation process: Dynamic modeling and numerical results 下载免费PDF全文
Nan Xu Yongsheng Ding William E. Schiesser Mayuresh V. Kothare 《American Institute of Chemical Engineers》2016,62(9):3432-3440
A dynamic model of polymer wet spinning coagulation process is proposed in this article. The model is based on the double diffusion phenomenon, phase separation process, continuity balance, and momentum balance of the entire coagulation process. The uniqueness of the model lies in its dynamic feature. The model can simulate the system's dynamic response to variations in system inputs/parameters. Steady‐state system solutions can also be produced as the long‐time solutions of the dynamic model; a settling time can be observed at the same time. This paper employs a computationally efficient method of lines numerical algorithm for solving the dynamic model. A simulation experiment on a selected non‐solvent‐solvent‐polymer ternary system is carried out to verify the model as well as the numerical method. The dynamic simulation results are analyzed and discussed. At the end of the article, h‐refinement and p‐refinement are used to confirm the spatial convergence of the numerical solutions. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3432–3440, 2016 相似文献
963.
Large Piezoelectricity and Ferroelectricity in Mn‐Doped (Bi0.5Na0.5)TiO3‐BaTiO3 Thin Film Prepared by Pulsed Laser Deposition 下载免费PDF全文
Qianru Lin Rui Ding Qian Li Yee Yan Tay Danyang Wang Yun Liu Yizhong Huang Sean Li 《Journal of the American Ceramic Society》2016,99(7):2347-2353
Mn‐doped (Bi0.5Na0.5)0.94Ba0.06TiO3 (MnBNBT) thin films were prepared on SrRuO3 (SRO)‐coated (001) SrTiO3 (STO) single crystal substrates by pulsed laser deposition under different processing conditions. Structural characterization (i.e., XRD and TEM) confirms the epitaxial growth of STO/SRO/MnBNBT heterostructures. Through the judicious control of deposition temperature, the defect level within the films can be finely tuned. The MnBNBT thin film deposited at the optimized temperature exhibits superior ferroelectric and piezoelectric responses with remanent polarization Pr of 33.0 μC/cm2 and piezoelectric coefficient d33 of 120.0 ± 20 pm/V. 相似文献
964.
Li2O–MgO–TiO2 ternary system is an important microwave dielectric ceramic material with excellent properties and prospect in both scientific research and application. A phase diagram of the Li2O–MgO–TiO2 ternary system was established in this article, based on earlier research results and our present work. Microwave dielectric properties with compositions in different regions of the phase diagram have been analyzed. We found that the 0.33 Li2MgTi3O8–0.67 Li2TiO3 ceramics sintered at 1200°C exhibited excellent dielectric properties: Q × f value = 80 476 GHz (at 7.681 GHz), εr = 24.7, τf = +3.2 ppm/°C. We also designed two ceramic systems in the Li‐rich region of the Li2O–MgO–TiO2 ternary system, which received little attention in the past decades, because many excellent single‐phase ceramics, such as Li2MgTiO4, Li2MgTi3O8 and MgTiO3, have been found in the Ti‐rich region. The ceramic systems have low sintering temperatures but also relatively poor dielectric properties. 相似文献
965.
Ron Li Guanglin Tang Jiachen Ding Timothy Logan Sarah D. Brooks Don R. Collins 《Aerosol science and technology》2018,52(6):666-678
Light scattering by kaolinite dust samples at 532 nm is studied using a newly developed laboratory apparatus. During the experiments, dust samples are suspended in water, aerosolized by a nebulizer, and then injected into the scattering zone, with or without going through a diffusion drier, to generate either dried dust particles or water droplets with dust inclusions. The light source is a dual wavelength (532 and 1064 nm) diode-pumped solid state laser. Light scattered by an ensemble of particles is collected by a charge-coupled device (CCD) camera, which is mounted on the rotating arm of a stepper motor. The stepper motor rotates the CCD to cover the scattering angle range from 3° to 177°. Polarized scattering light is measured for the horizontally and vertically polarized incident light. The apparatus is calibrated, using pure water droplets as the scattering media. The response function with respect to the scattering angle is obtained by comparing the measurements with Lorenz–Mie calculations and then used in the later data analysis. Measurements show that the backward scattering features of the water droplets are smoothened due to their dust inclusions. Numerical simulations and measurements are extensively compared and discussed. It is found that the Lorenz–Mie theory is inadequate to reproduce the scattering phase functions of either dust particles or water droplets with dust inclusions. A nonspherical aggregate model is applied to simulate the scattering phase functions. The simulation is able to reproduce the overall scattering features; however, substantial discrepancies still exist due to uncertainties in particle shape and refractive index.
Copyright © 2018 American Association for Aerosol Research 相似文献
966.
Nanotechnology has been successfully implemented in many applications, such as nanoelectronics, nanobiomedicine, and nanodevices. However, this technology has rarely been applied to the oil and gas industry, especially in upstream exploration and production. The oil and gas industry needs to improve oil recovery and exploit unconventional resources. The cost of research and oil production is under immense pressure, and it is becoming more difficult to justify such investment when the crude oil price is weak and depressed. There is a widespread belief that nanotechnology may be exploited to develop novel nanomaterials with enhanced performance to combat these technological barriers. Increasing funding resources from governmental and global oil industry have been allocated to exploration, drilling, production, refining, and wastewater treatment. For example, nanosensors allow for precise measurement of reservoir conditions. Nanofluids prepared using functional nanomaterials may exhibit better performance in oil production processes, and nanocatalysts have improved the efficiency in oil refining and petrochemical processes. Nanomembranes enhance oil, water and gas separation, oil and gas purification, and the removal of impurities from wastewater. Functional nanomaterials can play an important role in the production of smart, reliable, and more durable equipment. In this review paper, we summarize the research progress and prospective applications of nanotechnology and nanomaterials in the oil and gas industry. 相似文献
967.
An integrated process of catalytic hydrolysis and membrane separation for fatty acids production from lard oil 下载免费PDF全文
Enmin Lv Shaoxuan Ding Jie Lu Lixiong Du Zhuang Li Jianxin Li Shuguang Zhang Jincheng Ding 《加拿大化工杂志》2018,96(9):2014-2024
968.
Preparation of calcium aluminate cement by combustion synthesis and application for corundum‐based castables 下载免费PDF全文
Shoulei Yang Guoqing Xiao Donghai Ding Yun Ren Lihua Lv Pan Yang 《International Journal of Applied Ceramic Technology》2018,15(3):678-688
Calcium aluminate cement was prepared by combustion synthesis with CaO2, Al, and Al2O3 as raw materials. The effects of CaO/Al2O3 (C/A) molar ratios in raw materials on the phase compositions and morphologies of calcium aluminate were investigated in detail. It was found that when the C/A reduced from 1.1 to 0.74, the content of CaO·2Al2O3 (CA2) in products increased, whereas contents of CaO·Al2O3 (CA) and 12CaO·7Al2O3 (C12A7) decreased; when the C/A was 0.8, the phase composition of product (CS71) was equal to that of Secar71. Additionally, the crystallines of CA and CA2 in the product were reduced when the C/A molar ratio was decreased. And then, the bulk density, apparent porosity, permanent linear change, cold crushing strength (CCS), and cold modulus of rupture (CMOR) of the corundum‐based castables bonded with CS71, Secar7 were compared. The castables bonded with CS71 demonstrate obviously improved CCS, CMOR, and volume stability. 相似文献
969.
Residual thermal stress of SiC/Ti3SiC2/SiC joints calculation and relaxed by postannealing 下载免费PDF全文
Xiaobing Zhou Youbing Li Yifan Li Zhen Liu Hui Yang Shurong Ding Young‐Hwan Han Jaehyung Lee Shiyu Du Qing Huang 《International Journal of Applied Ceramic Technology》2018,15(5):1157-1165
Residual thermal stresses in SiC/Ti3SiC2/SiC joining couples were calculated by Raman spectra and simulated by finite element analysis, and then relaxed successfully by postannealing. The results showed that the thermal residual stress between Ti3SiC2 and SiC was about on the order of 1 GPa when cooling from 1300°C to 25°C. The thermal residual stresses can be relaxed by the recovery of structure disorders during postannealing. When the SiC/Ti3SiC2/SiC joints postannealed at 900°C, the bending strength reached 156.9 ± 13.5 MPa, which was almost twice of the as‐obtained SiC/Ti3SiC2/SiC joints. Furthermore, the failure occurred at the SiC matrix suggested that both the flexural strength of joining layer and interface were higher than the SiC matrix. 相似文献
970.
Generation of hydrogen under visible light irradiation with enhanced photocatalytic activity of Bi2WO6/Cu1.8Se for organic pollutants under Vis‐NIR light reign 下载免费PDF全文
Li‐Na Qiao Huan‐Chun Wang Yi‐Dong Luo Hao‐Min Xu Jun‐Ping Ding Shun Lan Yang Shen Yuan‐Hua Lin Ce‐Wen Nan 《Journal of the American Ceramic Society》2018,101(7):3015-3025
To make better use of solar light, a new Bi2WO6/Cu1.8Se photocatalyst active to visible and near‐infrared light has been synthesized by a facile hydrothermal method. The composites were characterized by X‐ray diffractometry (XRD), scanning electron microscopy (SEM), UV‐vis diffuse reflectance spectroscopy (DRS), and photoluminescene (PL). The photocatalytic activities of Bi2WO6/Cu1.8Se are evaluated by degrading Congo red solution and hydrogen generation from water. It was found that the molar percentage of Cu1.8Se had great effects on the morphology and photocatalytic property of the Bi2WO6/Cu1.8Se heterojunctions, and the composite with suitable molar amount of Cu1.8Se exhibits much enhanced photocatalytic activity for Congo red degradation under visible and near‐infrared light irradiation and for hydrogen generation under visible light compared to Bi2WO6. The significant improvement photocatalytic activity of the composite could be attributed to its good light absorption, suitable band gap structure, and effective separation of photogenerated electron‐hole pairs of Bi2WO6/Cu1.8Se heterojunction. This work presents an efficient multifunction photocatalyst owning the activity both for water splitting under visible light and for organic contaminants decomposition under visible‐near‐infrared light. 相似文献