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631.
Wilson Merchan-Merchan Alexei V. Saveliev Vu Nguyen 《Proceedings of the Combustion Institute》2009,32(2):1879-1886
The formation of carbon and metal-oxide nanostructures on molybdenum probes inserted in a counter-flow oxy-fuel flame is studied experimentally. Flame position and probe diameter were varied to achieve a controlled growth of carbon and metal-oxide nanostructures at fuel and oxygen-rich flame zones. Mo probes of 1-mm diameter were introduced in the flame at various heights, starting from the upper hydrocarbon-rich zone on the fuel side of the flame to the oxygen-rich zone on the oxidizer side. High density layers of carbon nanocoils (CNCs) and filamentous structures containing ribbon shapes and straight nanofibers were formed in the upper hydrocarbon-rich flame zone. The formation of carbon micro-trees was observed on the fuel side closer to the flame front. The structures formed in the oxidizer part of the flame were composed of molybdenum-oxides. MoO2 micron-sized channel structures were formed on the oxidizer side in the vicinity of the flame front. The micro-channels had rectangular and square-framed shapes; they were completely hollow, closed, and semi-open with a small circular cavity at their tips. The application of probes with diameters of 0.75 and 0.25 mm resulted in the formation of spectacular 3-D structures with unique and distinct morphologies. 相似文献
632.
Shafket Rasool Quoc Viet Hoang Doan Van Vu Chang Eun Song Hang Ken Lee Sang Kyu Lee Jong-Cheol Lee Sang-Jin Moon Won Suk Shin 《Journal of Energy Chemistry》2022,(1):236-245
Design and synthesis of low bandgap(LBG) polymer donors is inevitably challenging and their processability from a non-halogenated solvent system remains a hurdle to overcome in the area of highperformance polymer solar cells(PSCs).Due to a high aggregation tendency of LBG polymers,especially diketopyrrolopyrrole(DPP)-based polymers coupled with bithiophenes in the polymer backbones,their widespread adoption in non-ha logena ted solvent-processed PSCs has been limited.Herein,a novel LBG DPP-based... 相似文献
633.
Suhasini Kulkarni Elizabeth Chin Vu Tran Maggie K.-M. Ho Chieu Phan Monika Sommerhalter 《Monatshefte für Chemie / Chemical Monthly》2010,50(2):119-123
Abstract
The effect of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) on acid phosphatase (APase) from wheat germ in solution and in the sol–gel-encapsulated form was investigated to explore new methods of enzyme preparation with improved catalytic performance. APase was encapsulated in hydrogel beads made from tetramethyl orthosilicate. Compared with free APase, 20–28% enzymatic activity was retained in over nine catalytic cycles. Sol–gel encapsulation improved the thermal stability of APase. Heat shock exposure at 60 °C for 1 h resulted in activity decreasing by a factor of three, only, for sol–gel-encapsulated APase, in contrast with a factor of nine decrease for free APase. Addition of 10% v/v [BMIM][BF4] did result in a slight decrease of enzymatic activity for free and sol–gel-encapsulated APase, but resulted in a remarkable increase in alkaline pH tolerance of sol–gel-encapsulated APase. 相似文献634.
J. Vučina V. Šćepanović R. Drašković 《Journal of Radioanalytical and Nuclear Chemistry》1978,44(2):371-378
Some trace elements in samples from the aluminium industry (Aluminium Kombinat, Titograd, Yugoslavia) were determined by instrumental
neutron activation analysis. Samples characteristic for alumina production (bauxite, red sludge), reduction cell components
(alumina, anode, AlF3, cryolite) and aluminium produced (purity 99.5–99.7%) have been analyzed. 10 trace elements were determined under a given
set of working conditions and followed through the routine production. 相似文献
635.
Nguyen Vu Ngoc Mai Duong Thi Lim Nguyen Quang Bac Nguyen Thi Ha Chi Doan Trung Dung Ngo Nghia Pham Dao Ngoc Nhiem 《中国化学会会志》2020,67(2):242-245
In this study, nanoparticles of Fe2O3/Mn2O3 mixture were obtained using the sol–gel method. The synthesis uses the combination of polyvinyl alcohol (PVA) and tartaric acid (TA). Synthesized catalysts prove superior compared to those afforded from previous reports. To be specific, desired catalysts can be received at lower calcination temperature. Furthermore, their structures display higher uniformity in term of particle sizes. Finally, they show better performance for the photocatalytic degradation of model-persistent organic compounds. 相似文献
636.
Vu Kim Tuan 《Numerical Functional Analysis & Optimization》2013,34(3-4):387-394
In this paper, finite difference and finite element methods are used with nonlinear SOR to solve the problems of minimizing strict convex functionals. The functionals are discretized by both methods and some numerical quadrature formula. The convergence of such discretization is guaranteed and will be discussed. As for the convergence of the iterative process, it is necessary to vary the relaxation parameter in each iterations. In addition, for the model catenoid problem, boundary grid refinements play an essential role in the proposed nonlinear SOR algorithm. Numerical results which illustrate the importance of the grid refinements will be presented. 相似文献
637.
We prove that we can uniquely recover the coefficient of a one-dimensional heat equation from a single boundary measurement and provide a constructive procedure for its recovery. The algorithm is based on the well-known Gelfand–Levitan–Gasymov inverse spectral theory of Sturm–Liouville operators. 相似文献
638.
Retroviruses are one of the most commonly used vectors in ongoing gene therapy clinical trials. To evaluate and advance virus production on the microscale platform, we have created a novel microfluidic bioreactor for continuous retrovirus production. We investigated the growth kinetics of a retroviral packaging cell line in microfluidic bioreactors for several compartment sizes, and packaging cells perfused in the microdevices showed similar growth kinetics to those cultured in conventional static conditions. To evaluate the efficiency of retrovirus production, virus titers from the microdevices were compared to those obtained from static tissue culture. When retrovirus production and collection were maintained at 37 degrees C, virus production levels were comparable for the microdevices and static tissue culture conditions. However, immediate cold storage downstream of the packaging cells in the microdevices resulted in 1.4- to 3.7-fold greater active virus production levels with the microdevices compared to the conventional static conditions over a 5 day period. Lastly, the use of microfluidics for virus production provides a continuous supply of virus supernatant for immediate infection of target cells or for preservation and storage. Such devices will be valuable for the optimization of production and evaluation of retroviruses and other viral vectors for gene therapy applications. 相似文献
639.
We study the stress state in the vicinity of a planar surface crack whose boundary is described by the limaçon of pascal. The problem is solved by a conformal mapping of the region occupied by the crack onto part of a disk in the plane. This makes it possible to apply a numerical-analytic method for solving systems of double singular integral equations of the mathematical theory of cracks. We present the graphs of the dependence of the stress intensity factor on the angular coordinate for cracks that are part of a limaçon of Pascal. 相似文献
640.
An improved optical decryption system based on kinogram encoding is proposed. The decrypted phase image is obtained by optically descrambling the encrypted image with the decrypting phase key. Only a single Fourier lens is needed to generate intensity patterns from the decrypted phase image. The design and simulation results have confirmed the proposed technique as a novel, simple, and robust decryption architecture. 相似文献