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221.
N. Schönfeldt 《Journal of the American Oil Chemists' Society》1968,45(2):80-82
The course of the lime soap-dispersing action of various surfactants has been examined by use of a titrimetric method. Two
types of dispersants can be distinguished. With the addition of a surfactant of the first type, the concentration of the dispersed
fatty acid increases gradually. If a surfactant of the second type is used, a definite increase of the fatty acid concentration
first occurs after the addition of considerable amounts of the dispersant.
Ethylene oxide adducts and sodium triethylene glycol monolauryl ether sulfate behave like dispersants of the first type whereas
sodium dodecylbenzenesulphonate and sodium lauryl sulfate belong to those of the second type. The dispersing action of both
types of surfactants is discussed. 相似文献
222.
Selective Hydrogenation of Fats and Derivatives Using Ziegler-Type Organometallic Catalysts I: Selective Hydrogenation of Methyllinoleat and Other Dienic Compounds with Isolated Double Bonds Homogeneous catalysts of Ziegler-Sloan-Lapporte-type, containing nickel, cobalt or palladium, were used to hydrogenate methyllinoleate under very mild conditions selectively to monounsaturated products. The question, wether this selectivity is caused by the 1,4-position of the olefinic double bonds, led to hydrogenation experiments with non-conjugated α,ω-dienes of different chain length. A significant selectivity was only observed for the reduction of 1,4-pentadiene to pentene, dienes with greater distance between the double bonds than in linoleic acid were hydrogenated with less selectivity. To explain these facts, a kinetic model, including catalyst-substrate-complexes of different stabilities, is proposed. 相似文献
223.
Peter Meszmer Karla Hiller Steffen Hartmann Alexey Shaporin Daniel May Raul David Rodriguez Jörg Arnold Gianina Schondelmaier Jan Mehner Dietrich R. T. Zahn Bernhard Wunderle 《Microsystem Technologies》2014,20(6):1041-1050
In this paper, a novel concept of a thermo-mechanical MEMS actuator using aluminum thin-film heaters on a thermal oxide for electrical insulation is presented. The actuator is part of an universal tensile testing platform for thermo-mechanical material characterization of one dimensional materials on a micro- and nano-scopic scale under different environmental conditions, as varying temperatures, pressure, moisture or even vacuum and is realised in BDRIE technology. It is shown, that the actuator concept fulfills the requirements for the use in a tensile loading stage along with heterogeneously integrated nanofunctional elements, following a specimen centered approach in line with bottom-up self-assembly processes. Simulation and experiment agree very well in the thermal and mechanical domain and allow subsequent optimisation of the actuator performance. 相似文献
224.
Fides Aarts Harco Kuppens Jan Tretmans Frits Vaandrager Sicco Verwer 《Machine Learning》2014,96(1-2):189-224
Using a well-known industrial case study from the verification literature, the bounded retransmission protocol, we show how active learning can be used to establish the correctness of protocol implementation I relative to a given reference implementation R. Using active learning, we learn a model M R of reference implementation R, which serves as input for a model-based testing tool that checks conformance of implementation I to M R . In addition, we also explore an alternative approach in which we learn a model M I of implementation I, which is compared to model M R using an equivalence checker. Our work uses a unique combination of software tools for model construction (Uppaal), active learning (LearnLib, Tomte), model-based testing (JTorX, TorXakis) and verification (CADP, MRMC). We show how these tools can be used for learning models of and revealing errors in implementations, present the new notion of a conformance oracle, and demonstrate how conformance oracles can be used to speed up conformance checking. 相似文献
225.
Pavel Krömer Jan Platoš Václav Snášel 《International journal of parallel programming》2014,42(5):681-709
Graphic processing units (GPUs) emerged recently as an exciting new hardware environment for a truly parallel implementation and execution of Nature and Bio-inspired Algorithms with excellent price-to-power ratio. In contrast to common multicore CPUs that contain up to tens of independent cores, the GPUs represent a massively parallel single-instruction multiple-data devices that can nowadays reach peak performance of hundreds and thousands of giga floating-point operations per second. Nature and Bio-inspired Algorithms implement parallel optimization strategies in which a single candidate solution, a group of candidate solutions (population), or multiple populations seek for optimal solution or set of solutions of given problem. Genetic algorithms (GA) constitute a family of traditional and very well-known nature-inspired populational meta-heuristic algorithms that have proved its usefulness on a plethora of tasks through the years. Differential evolution (DE) is another efficient populational meta-heuristic algorithm for real-parameter optimization. Particle swarm optimization (PSO) can be seen as nature-inspired multiagent method in which the interaction of simple independent agents yields intelligent collective behavior. Simulated annealing (SA) is global optimization algorithm which combines statistical mechanics and combinatorial optimization with inspiration in metallurgy. This survey provides a brief overview of the latest state-of-the-art research on the design, implementation, and applications of parallel GA, DE, PSO, and SA-based methods on the GPUs. 相似文献
226.
Jochen Schütz 《Journal of scientific computing》2014,60(2):438-456
We apply the concept of asymptotic preserving schemes (SIAM J Sci Comput 21:441–454, 1999) to the linearized \(p\) -system and discretize the resulting elliptic equation using standard continuous Finite Elements instead of Finite Differences. The fully discrete method is analyzed with respect to consistency, and we compare it numerically with more traditional methods such as Implicit Euler’s method. 相似文献
227.
Th. Braun M. Wohlers T. Belz G. Nowitzke G. Wortmann Y. Uchida N. Pfänder R. Schlögl 《Catalysis Letters》1997,43(3-4):167-173
The influence of fullerenes and related support materials on the structural and catalytic properties of ruthenium was investigated.
Catalysts based on C60, raw fullerene black, extracted fullerene black, cathode deposit and graphite were prepared by an impregnation/activation
procedure with Ru3CO12. The local co-ordination sphere of the resulting highly dispersed X-ray amorphous ruthenium was investigated by means of
EXAFS. The dominating role of the presence of non-six-membered carbon rings on the structure and the stability of the Ru particles
will be illustrated.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
228.
Aqueous photoresists that are capable of higher resolutions than are currently employed by the cathode ray tube (CRT) industry were developed by combining photoactivators, which activate at shorter UV wavelengths with polyvinylpyrrolidone (PVP). Two photoactivators were synthesized: 4,4′‐diazido‐2,2′‐biphenyl disodium disulfonate (DABP), which has a maximum absorbance at 264 nm, and 4,4′‐diazido‐2,2′‐biphenylethane disodium disulfonate (DABPE), which has a maximum absorbance at 258 nm. The PVP/DABP and PVP/DABPE photoresists successfully imaged a pattern with resolution as small as 4.4 μm with photoactivator concentrations greater than 20% of the PVP concentration. Addition of silane and emulgen greatly improved the performance of the photoresists with more uniform coatings of thicknesses of up to 1.4 μm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1637–1644, 2006 相似文献
229.
Ivan imkovic Jan Pastýr Miroslav Antal Karol Balog tefan Koik Jan Pla
ek 《应用聚合物科学杂志》1987,34(3):1057-1061
Lignocellulose materials were modified with 3-chlor-2-hydroxypropyltrimethylammoniumchloride, 1,3-bis(3-chlor-2-hydroxypropyl)imidazoliumhydrogensulphate, and 2-chlorethyl-sodiumsulphonate and the flame-retardant properties of materials obtained were studied. The flame-retardant effect was proved using the limited oxygen index (LOI) method and values up to 32.8 vol % of oxygen were determined. The LOI values were higher when the modification was done without using NaOH for activation, but in that case the alkylating groups were not chemically bonded to the material. The NaOH activation was necessary to obtain material with flame-retardant properties stable against washing. No synergistic effects were observed when the material was modified with both nitrogen- and sulfur-containing groups. 相似文献
230.
Schüth F. Busch O. Hoffmann C. Johann T. Kiener C. Demuth D. Klein J. Schunk S. Strehlau W. Zech T. 《Topics in Catalysis》2002,21(1-3):55-66
High-throughput experimentation in catalysis comprises the following components: (i) automated high-throughput synthesis, (ii) testing in Stage I and Stage II, for which to some extent novel assays are necessary, (iii) data handling and experimental design tools, and (iv) robotics. This contribution covers these topics, using examples from the research of the authors, but also from the literature, in order to illustrate the problems and opportunities associated with high-throughput experimentation in catalysis, focusing particularly on heterogeneous catalysis. 相似文献