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排序方式: 共有260条查询结果,搜索用时 15 毫秒
1.
Mobile Networks and Applications - Project MindCatcher is an art/research project which has the intention to explore the potential of interactive artistic environments for measuring and a better... 相似文献
2.
The objective of this study is to analyze volatile organic compound (VOC) concentrations in Taiwan's drinking water supply. Focusing on Taiwan's three major metropolitan areas--Taipei, Taichung and Kaohsiung (in the north, middle and south, respectively)--171 samples were taken from tap water and 68 from boiled water. Tests showed VOC concentrations were highest in Kaohsiung. This is due to different water sources and methods of treatment. Except for bromoform, trihalomethane (THM) concentrations were highest. Detection rates of toluene and 1,2-dichloroethane were slightly higher than other VOC compounds. VOC concentrations decreased significantly after water was boiled. THMs had a removal rate from 61% to 82%. The authors conclude that the three metropolitan areas contain significantly different levels of VOCs and that boiling can significantly reduce the presence of VOCs. Other sources of pollution that contaminate drinking water such as industrial plants and gas stations must be further investigated. 相似文献
3.
Analog Integrated Circuits and Signal Processing - This paper proposes a circuit configuration to emulate the behaviour of a floating/grounded incremental/decremental flux-controlled meminductor,... 相似文献
4.
Molecular spiders are nanoscale walkers made with DNA enzyme legs attached to a common body. They move over a surface of DNA substrates, cleaving them and leaving behind product DNA strands, which they are able to revisit. Simple one-dimensional models of spider motion show significant superdiffusive motion when the leg-substrate bindings are longer-lived than the leg-product bindings. This gives the spiders potential as a faster-than-diffusion transport mechanism. However, analysis shows that single-spider motion eventually decays into an ordinary diffusive motion, owing to the ever increasing size of the region of cleaved products. Inspired by cooperative behavior of natural molecular walkers, we propose a symmetric exclusion process model for multiple walkers interacting as they move over a one-dimensional lattice. We show that when walkers are sequentially released from the origin, the collective effect is to prevent the leading walkers from moving too far backwards. Hence, there is an effective outward pressure on the leading walkers that keeps them moving superdiffusively for longer times, despite the growth of the product region. Multi-spider systems move faster and farther than single spiders or systems with multiple simple random walkers. 相似文献
5.
Mihajlo C. Stefanovic Jelena A. Anastasov Aleksandra M. Cvetkovic Goran T. Djordjevic 《Wireless Communications and Mobile Computing》2015,15(18):2141-2149
The outage performance of the amplify‐and‐forward relaying strategies over mutually uncorrelated extended generalized‐K fading channels is addressed in this paper. The attention is dedicated to the analyses of the noise‐limited and also interference‐limited environment. The new analytical expression for outage probability of observed relaying system in the presence of thermal noise is derived using the method for approximating equivalent signal‐to‐noise ratio. In addition, the outage performance is studied for the dual‐hop system when only the single dominant co‐channel interference is inherent at the relay and destination node. The correctness of the proposed mathematical derivations is verified by simulations. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
6.
Milan Stakić Dejan Cvetinović Predrag Škobalj Vuk Spasojević 《Chemical Engineering Research and Design》2014
Despite benefiting from vast fuel reserves, combustion of low-rank coals is commonly characterized by low thermal efficiency and high pollutant emissions, partly due to high moisture content of the coals in question. Thus, removal of moisture from low-rank coals is deemed an important quality upgrading method. The paper provides an overview of the current status of low-rank coal upgrading technologies, particularly with respect to utilization of drying and dewatering procedures. In order to examine the influence of relevant parameters on the moisture removal process, a model of convective coal drying in a packed, as well as in a fluid bed combustion arrangement, is developed and presented. Product-specific data (intraparticle mass transfer, gas–solid moisture equilibrium) related to the coal variety addressed herein (lignite) are obtained through preliminary investigations. Effective thermal conductivity of the packed bed as defined by Zehner/Bauer/Schlünder is used to define heat transfer mechanisms occurring in the packed bed. Similar two-phase fluidization model has been validated for different types of biomaterials. 相似文献
7.
Novaković MM Stevanović SM Gorjanović SŽ Jovanovic PM Tešević VV Janković MA Sužnjević DŽ 《Journal of food science》2011,76(4):C663-C668
This study was conducted to investigate the influence of different drying treatments on antioxidant (AO) activity and phenolic content of raspberry (Rubus idaeus), cultivar Willamette. Whole raspberry fruits were dried convectively (air-drying), osmotically, and freeze-dried. Acetone-water extracts of fresh and dried raspberries were assessed for total phenolic content by standard Folin-Ciocalteau method. Two AO assays were applied, a recently developed direct current (DC) polarographic assay based on decrease of anodic oxidation current of hydrogen peroxide and widely used radical scavenge against the 1,1-diphenyl-2-picrylhydrazyl (DPPH). Strong correlation has been obtained between both AO assays and total phenolic content. In addition, some individual phenolic compounds present in raspberry have been assessed using DPPH and DC polarographic assay. Comparison and evaluation of drying methods has been based on preservation of AO activity and total phenolic content. Obtained results confirmed superiority of freeze-drying; convective drying caused slight changes while osmotic dehydration showed a significant decrease of phenolic compounds and AO activity. 相似文献
8.
Ability of laboratory determination of a sand behaviour in static and dynamic loading conditions are influenced by (among other things): sample preparation, number of tests, size of strains, speed of loading and averaging of the errors during examination. Dynamic load per se causes accumulation of the pore water pressure and the phenomenon of stiffening-threshold-degradation which makes the understanding of the sand behaviour more difficult. The complex behaviour of granular material, i.e. sand, is caused by chemical and physical properties of individual particles and their mutual interaction. Obviously, these interrelationships could not be analysed on the basis of laboratory testing. One way to analyse it is numerically, with algorithm that takes into consideration the characteristics of individual particles as well as their interaction in the sand matrix. Discrete element method (DEM) is a numerical method which takes into consideration the discrete nature of sand and shape of particles and is used as an elementary research tool for sand behaviour. Program package PFC3D is based on DEM and allows the modelling of the laboratory equipment, materials and calibration of its micro-characteristics, based on experimental results. The research of cyclic threshold shear strain for degradation in sand includes observation and visualization of the sample preparation (creation of the material skeleton), pouring of the material (transition from liquid to meta-stable state), influence of the particle shape (interlocking, arching), consolidation (deformation of the skeleton) and development and braking of force chains through the sample. This paper explores the suitability of the selected numerical method for modelling of NGI-DSS device, calibration of the tested granular material (Nevada sand) and preparation of the sample for testing and presentation of the stiffening-threshold-degradation phenomenon. 相似文献
9.
Anna Fensel Slobodanka Tomic Vikash Kumar Milan Stefanovic Sergey V. Aleshin Dmitry O. Novikov 《Informatik-Spektrum》2013,36(1):46-57
As the urgent need for efficient and sustainable energy usage becomes ever more apparent, interest in Smart Homes is on the rise. The SESAME-S project (SEmantic SmArt Metering – Services for Energy Efficient Houses) uses semantically linked data to actively assist end-consumers in making well-informed decisions and controlling their energy consumption. By integrating smart metering and home automation functionality, SESAME-S works to effectively address the potential mass market of end-consumers with an easily customizable solution that can be widely implemented in domestic or business environments, with expected savings of over 20?% from the total energy bill. The developed system is a basis for conceptualizing, demonstrating, and evaluating a variety of innovative end-consumer services and their user interface paradigms. In this paper, we present the SESAME-S system as a whole and discuss the semantically enabled services, demonstrating that such systems may have broad acceptance in the future. The data obtained through such systems will be invaluable for future global energy-efficiency strategies and businesses. 相似文献
10.
An approach to the performance analyses of dual selection combining (SC) diversity receiver over correlated a ?m fading channels with the arbitrary parameters is presented. Fading between the diversity branches and interferers is correlated and distributed with α ? μ distribution. Infinite series expressions are obtained for the output SIR?s probability density function (PDF), cumulative distribution function (CDF) and an important measure of the system?s performances, the outage probability (OP). An average error probability is efficiently evaluated for coherent and non-coherent modulation schemes such as coherent frequency-shift keying (CFSK), coherent phase-shift keying (CPSK), binary frequency-shift keying (BFSK) and binary differentially phase-shift keying (BDPSK). Numerical results are presented to show the effects of various parameters such as fading severity, input SIR unbalance and the level of correlation between received desired signals and interferences on system?s performances. 相似文献