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排序方式: 共有1462条查询结果,搜索用时 15 毫秒
931.
A new technique of nondestructively assessing the compression strength of concrete, which employs artificial neural networks, is presented. A data set based on results of testing concretes (with a 28-day strength of 24–105 MPa) by different nondestructive methods was used to train and test an artificial neural network. The methodology of neural identification of the strength is described. The obtained results, including those of the practical verification of the technique, are reported. 相似文献
932.
Józef Mazurkiewicz Krzysztof Rębilas P. Tomasik 《European Food Research and Technology》2001,212(3):369-373
Rheological studies of aqueous aspartame blends with d-fructose, d-glucose, maltose and sucrose revealed that only sucrose-aspartame blends provided an increase in the viscosity. Polarimetric studies of the blends together with computer MM+ simulations involving energy optimization for such blends and for solutions of saccharides showed that the energies of hydration of sucrose and aspartame are similar and higher than those for aqueous solutions of other saccharides. The hydration coats of these species are least organized. The results showed the formation of a common hydration coat for both solutes. The hydrodynamic shape of the resulting aggregate is responsible for the increase in viscosity of these blends. Other saccharides formed hydrates that remained independent of the hydrated aspartame. 相似文献
933.
A Constructive Approach to Stabilizability and Stabilization of a Class of nD Systems 总被引:1,自引:1,他引:0
Lin Zhiping Lam James Galkowski Krzysztof Xu Shengyuan 《Multidimensional Systems and Signal Processing》2001,12(3-4):329-343
This paper presents a constructive approach to the problem of output feedback stabilizability and stabilization of a class of linear multidimensional (nD, n>2) systems, whose varieties of the ideals generated by the reduced minors are infinite with respect to not more than two variables. The main idea of the proposed approach is to decompose the variety of an nD system in this class into a union of several varieties, each of which is defined by polynomials in just two variables. The new method can be considered as a combination of Gröbner bases and existing results on two-dimensional (2D) digital filter stability tests and on stabilizability and stabilization of 2D systems. An example is illustrated. 相似文献
934.
System Level Hardware/Software Partitioning Based on Simulated Annealing and Tabu Search 总被引:18,自引:1,他引:17
Petru Eles Zebo Peng Krzysztof Kuchcinski Alexa Doboli 《Design Automation for Embedded Systems》1997,2(1):5-32
This paper presents two heuristics for automatic hardware/software partitioning of system level specifications. Partitioning is performed at the granularity of blocks, loops, subprograms, and processes with the objective of performance optimization with a limited hardware and software cost. We define the metric values for partitioning and develop a cost function that guides partitioning towards the desired objective. We consider minimization of communication cost and improvement of the overall parallelism as essential criteria during partitioning. Two heuristics for hardware/software partitioning, formulated as a graph partitioning problem, are presented: one based on simulated annealing and the other on tabu search. Results of extensive experiments, including real-life examples, show the clear superiority of the tabu search based algorithm. 相似文献
935.
Krzysztof Piko 《Applied Energy》2003,75(3-4):213-220
Large amounts of fuels, burned in various types of furnaces are one of the main sources of pollution in the environment. Flue gases pollute the atmosphere and the associated ashes pollute soil and water. To compare the influence of various fuels burned in different installations on the environment, one universal index would be helpful. Such a coefficient, which represents the harmfulness of combustion processes of a particular fuel in a particular installation, is defined in this paper. This coefficient takes into account the composition of the fuel, the thermal efficiency of the installation, the type and process efficiency of creation of harmful compounds in the combustion chamber, efficiency of cleaning devices, ability of emitter to propagate pollutants into the atmosphere, as well as the relative toxicity of various components. Finally methods of calculation of propagation of pollutants in the atmosphere are introduced. All these factors are essential for a reliable assessment and comparison of fuel and installations. An individual coefficient of harmfulness could be calculated for each compound present in the flue gases as well as a total coefficient for all compounds. Each compound created in the combustion processes is the source of many types of environmental impact. It could have significant influences on human health, plants and animals as well as for example on the corrosion process taking place in many different installations. We have to take into consideration that the result of a combustion process could appear in many different places, sometimes distant from the place of the process itself. All these results should be analyzed and introduced into the universal coefficient of “harmfulness” of specific compound. Economic parameters and methods are important and therefore are also introduced into the assessment method presented in the paper. In this way we are able to compare the values of extremely different phenomena such as a human health and corrosion. 相似文献
936.
Influence of experimental conditions on electrochemical behavior of Prussian blue type nickel hexacyanoferrate film 总被引:6,自引:0,他引:6
Silvia Zamponi Mario Berrettoni Pawel J. Kulesza Krzysztof Miecznikowski Marcin A. Malik Oktawian Makowski Roberto Marassi 《Electrochimica acta》2003,48(28):1840-4269
Electrochemical properties of thin films and microcrystalline precipitates of nickel(II) hexacyanoferrate(II, III), NiHCNFe, are strongly dependent on the method of their preparation and experimental conditions of their investigation. The films have been generated on both inert (gold) and parent metal (nickel) substrates. Interpretation of voltammetric responses of nickel hexacyanoferrate microstructures on electrodes is supported with the data of elemental analysis estimations obtained using atomic absorption and surface examination based on X-ray energy dispersive spectroscopy. Both electrodeposited films and mechanically-attached precipitates of nickel hexacyanoferrate constitute mixed structures in which the relative ratios of K and Ni to Fe reflect composition of a solution for modification, choice of the deposition potential and time, and the time and potential limits of exposure of the system to voltammetric potential cycling in potassium salt supporting electrolyte. We demonstrate here that the more positive set of peaks of nickel hexacyanoferrate is related to the electroactivity of the form containing relatively larger amount of potassium and smaller of nickel. On the other hand, the more negative set of the system’s peaks shall be attributed to the form that is largely potassium depleted and containing more nickel relative to iron. In this context, the use of the previously proposed approximate formulas, K2Ni[FeII(CN)6] and KNi1.5[FeII(CN)6], for the predominant nickel hexacyanoferrate (reduced) forms is justified. 相似文献
937.
Bartosz awniczek Grzegorz Majka Pawe Sowikowski Krzysztof Zieliski Sawomir Zieliski 《Electronic Notes in Theoretical Computer Science》2003,82(6):77
The paper describes a grid infrastructure monitoring service based on Jiro and JMX. Involvement of those technologies gives the programmer ease of instrumentation, dynamic configuration and simple to use discovery and notification mechanisms. Moreover, building the system over existing standards accepted by the IT industry makes this process stable in longer period of time. The goals of the autors of the service's concept were not only to provide the user with yet another front-end for SNMP, but also to let the system resolve typical problems by involving existing or forthcoming technologies supporting declarative way of programming. Being structured as a framework, the system allows the user to describe rules that define the actions taken by the system and conditions, upon which the actions should be taken. The system is currently developed further by the Distributed Systems Research Group at the University of Mining and Metallurgy in Kraków. 相似文献
938.
Agata Gitlin Dr. Dawid Dębowski Natalia Karna Prof. Anna Łęgowska Dr. Marit Stirnberg Prof. Michael Gütschow Prof. Krzysztof Rolka 《Chembiochem : a European journal of chemical biology》2015,16(11):1601-1607
A series of 17 new analogues of trypsin inhibitor SFTI‐1 were designed and synthesized to obtain matriptase‐2 inhibitors. A number of the modified bicyclic peptides displayed much higher affinity towards matriptase‐2 than towards the highly homologous matriptase‐1. Replacement of Lys5 by Arg in the wild‐type SFTI‐1 led to an 11‐fold increase in the matriptase‐2 inhibitory activity. Replacement of Arg2 by its enantiomer (D ‐arginine) slightly lowered the inhibition of matriptase‐2, but almost completely abolished the affinity towards matriptase‐1, thus yielding the most selective matriptase‐2 inhibitor. This is the first report describing inhibitors of the recently discovered matriptase‐2 based on the SFTI‐1 structure. The results showed that SFTI‐1 is a promising scaffold for the design of potent and selective inhibitors of this enzyme. 相似文献
939.
Adrian Barylski Joanna Maszybrocka Marian Kupka Krzysztof Aniołek Sławomir Kaptacz 《应用聚合物科学杂志》2015,132(31)
PTFE with a 15% addition of graphite was subjected to irradiation using an electron beam of 10 MeV energy with absorbed doses of 26, 52, 78, 104, and 156 kGy. The effect of electron‐beam irradiation on the mechanical, sclerometic, and tribological properties, the crystallinity degree, and the morphology of the polymer surface was examined. It was found that the modification through irradiation entailed a gradual increase in the degree of crystallinity, which had a direct influence on the mechanical properties. An increase in the hardness, Young's modulus, and compressive strength of the polymer irradiated with an electron beam was also demonstrated. The electron‐beam irradiation reduced the value of components of the work‐of‐indentation, showing the growing resistance to deformation. An analysis of the scratch test parameters showed a reduced depth of penetration of the indenter into the material, proportionally to the irradiation value, at relatively constant values of the scratch depth after scratching load removal. A stereometric analysis of the scratch traces on the material allowed to determine coefficients of the wear micromechanism, β, and resistance to wear, Wβ. It was found that after irradiation (especially with a dose of 4 × 26 kGy), a significant quantity of the material showed traces of ploughing, which meant a positive effect on the wear mechanism. The value of the wear resistance coefficient Wβ for PTFE subjected to the absorbed irradiation dose increased intensively, which portended a significant reduction of the tribological wear compared to the nonirradiated material. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42348. 相似文献
940.
Effects of ultrasonic assisted processing and clay nanofiller on dielectric properties and lithium ion transport mechanism of poly(methyl methacrylate) based plasticized polymer electrolytes
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Shobhna Choudhary Adam Bald Ram Jeewan Sengwa Dorota Chęcińska‐Majak Krzysztof Klimaszewski 《应用聚合物科学杂志》2015,132(27)
Lithium ion conducting solid polymer electrolyte (SPE) films consisted of poly(methyl methacrylate) (PMMA) matrix with lithium perchlorate as a dopant ionic salt, poly(ethylene glycol) as plasticizer and montmorillonite clay as inorganic nanofiller have been prepared by classical solution casting and high intensity ultrasonic assisted solution casting methods. The X‐ray diffraction study confirmed the amorphous structure of all these PMMA‐based solid electrolytes and the clay nanosheets existed in exfoliated form in their amorphous phase. Dielectric relaxation spectroscopy had been employed for the investigation of complex dielectric function, ac electrical conductivity, electric modulus, and impedance spectra of these electrolytes over the frequency range from 20 Hz to 1 MHz. It was observed that the dielectric properties and ionic conductivity of the electrolytes strongly depended on the sample preparation methods, and also had changes with addition of the clay nanofiller. Temperature‐dependent dielectric study of the electrolyte films confirmed that their dc ionic conductivity and conductivity relaxation time values obeyed the Arrhenius behavior. This study also revealed that the lithium ion transportation in the ion–dipolar complexes of these electrolytes occurred through hopping mechanism and it was correlated with the conductivity relaxation time. Preparation of these electrolyte films through ultrasonic assisted solution casting method increased the ionic conductivity by more than one order of magnitude in comparison to that of the classical solution casting method, which revealed that the former was a novel method for the preparation of these SPEs of relatively enhanced ionic conductivity. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42188. 相似文献