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151.
Enrico Fabrizi Caterina Giusti Nicola Salvati Nikos Tzavidis 《Papers in Regional Science》2014,93(3):685-701
Measures of economic well‐being are often needed for geographically small areas, as economic indicators may be distributed unevenly among the subsets of relatively small regions. We consider small area estimation of average equivalized income. Disposable household income data are usually available only for a sample of households, typically too small to provide reliable estimates for small regions. We consider a small area estimation technique that is robust to outliers, produces results consistent with design weighted estimates obtained for larger areas and yield maps with approximately no shrinkage. The proposed methodology is applied to the Local Labour Systems in Tuscany (Italy). 相似文献
152.
《Materials Science & Technology》2013,29(1):371-376
AbstractThe influence of R ratio in the range 0·05–0·4 on the ambient temperature fatigue crack growth behaviour of an austenitic stainless steel weld, SS 316(N), has been studied. Results indicate that the cyclic threshold stress intensity factor ΔKth increases with decreasing R ratio. The data are compared with those for SS 316, SS 316L and SS 316L(N) base materials from the literature, and various approaches dealing with the R ratio effects are examined. Zhang’s model considering the contribution of the crack tip plasticity to the fundamental fatigue crack propagation process does provide a consistent interpretation for the data. 相似文献
153.
154.
《International Journal of Hydrogen Energy》2019,44(7):3636-3648
Nickel hydroxide nanoparticles were fabricated on Vulcan XC-72R carbon black using various reducing agents through assisted microwave polyol process. The formed electrocatalysts using sodium borohydride [Ni(OH)2/C–NB], ethylene glycol [Ni(OH)2/C–EG] and a mixture of them [Ni(OH)2/C–EGNB] displayed an electrocatalytic activity towards urea oxidation in NaOH solution. The oxidation peak potential and current density values were greatly influenced by the employed reducing agent. Lower onset and peak potential values were measured at Ni(OH)2/C–EGNB, while Ni(OH)2/C–EG exhibited the highest oxidation current density during urea oxidation reaction. Electroactive surface area measurements revealed that the number of available active sites for the oxidation reaction was arranged in an ascending order as Ni(OH)2/C–NB < Ni(OH)2/C–EGNB < Ni(OH)2/C–EG. The diffusion coefficient of urea molecules at Ni(OH)2/C–EG and Ni(OH)2/C–EGNB was 14.69 and 5.90 times higher than that at Ni(OH)2/C–NB. Stable performance was measured at all studied electrocatalysts over prolonged operation suggesting their valuable application as efficient anode materials in direct urea oxidation fuel cells. 相似文献
155.
This paper presents a prototype software system for visualization and analysis of hydrologic data that provides interoperability between the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) Hydrologic Information System (HIS) and the R statistical computing environment. By linking these two systems within a single desktop software application, an integrated hydrologic data management and analysis environment has been created that simplifies the process used by scientists and engineers to find, access, organize, and analyze the hydrologic data needed in modeling and managing hydrologic and environmental systems. The implementation of this work is a software plug-in for the CUAHSI HIS HydroDesktop software system called HydroR. We describe the design, graphical user interface, and implementation of the HydroR plug-in. An example application of HydroR is presented in which total suspended solids concentrations are modeled for the Little Bear River using a regression developed from turbidity and total suspended solids observations downloaded from the CUAHSI HIS using HydroDesktop. Finally, we conclude with a summary of our experience in developing interoperability between HIS and R and suggest future developments that can extend the capabilities we have developed. 相似文献
156.
车站建筑群作为轨道类交通体系中的一部分,具有城市代表性,它是城市基础性建筑。要把车站建筑工程与其他基础性工程视为同等重要的工作来考虑。在逐步完善和优化资源配置的过程中,最终建设与这个城市发展配套的现代化交通轨道衔接体系。 相似文献
157.
Single‐Stage ZVS‐PWM AC‐AC Power Converter Using All SiC Power Module for High‐Frequency Induction Heating Applications
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This paper presents a novel prototype of a single‐stage zero voltage soft‐switching pulse‐width modulation ‐controlled ac‐ac converter with a silicon carbide (SiC)‐MOSFET/SiC‐SBD power module for high‐frequency (HF) induction heating (IH) applications. The newly developed ac‐ac converter can achieve higher efficiency than a Si‐IGBT/Si‐PN diode power module‐based prototype due to a low ON‐resistance of SiC‐MOSFET and a low forward voltage of SiC‐SBD under the condition of HF switching. The performances of the new prototype converter are evaluated by experiment with a single‐phase IH utensil of ferromagnetic stainless metal, after which the high‐efficiency and low switching noise characteristics due to the all SiC power module are actually demonstrated. 相似文献
158.
Combination of Reaction and Separation in Heterogeneous Catalytic Hydrogenation of Ethylformate
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Gerson Martin Carla Pereira Frank Pettersson Henrik Saxén Dmitry Y. Murzin Alírio Rodrigues Tapio Salmi 《化学工程与技术》2015,38(5):804-812
Continuous hydrogenation reaction of ethyl benzoylformate was studied over a (–)‐cinchonidine (CD)‐modified Pt/Al2O3 catalyst. The catalyst showed a good stability, and high enantioselectivity was achieved in the fixed‐bed reactor. Chromatographic separation of (R)‐ and (S)‐ethyl mandelate originating from a post‐continuous hydrogenation reaction of ethyl benzoylformate over the (–)‐CD‐modified Pt/Al2O3 catalyst was investigated in the same reaction mixture. A commercial column filled with a chiral selector resin was chosen as a perspective preparative‐scale adsorbent. Since adsorption equilibrium isotherms were linear within the entire investigated range of concentrations, they were determined by pulse experiments for the isomers present in a post‐reaction mixture. Breakthrough curves were measured and described successfully by the dispersive plug‐flow model with linear driving force approximation. 相似文献
159.
林成东 《有色冶金设计与研究》2020,(2):27-30
利用艾默生控制系统旧版本软件,开发开关量设备控制模块比较繁琐,需要借助大量的逻辑功能块与条件判断功能块进行辅助开发,程序结构复杂,逻辑不清晰,容易出错。新版本软件推出的新功能块解决了以上问题。以某火法铜冶炼工程为例,结合冶炼工艺特点,程序开发过程中通过解决不熟悉新功能块特点应用难问题,风机、泵、电动阀等设备控制模块开发难问题,开发出了满足控制要求的各种设备控制模块。利用新版本软件的新功能块,开发的设备控制模块在火法铜冶炼得到成功应用。 相似文献
160.
Condensation is usually assumed to begin when the bulk enthalpy reaches the saturated vapor enthalpy, which leads to discontinuity of heat transfer coefficient calculation in modeling. This paper addresses the discontinuity by showing the presence of condensation in desuperheating region when the wall temperature decreases below the saturation temperature at any operating condition. The experiments have been conducted with R134a, R1234ze(E) and R32 for mass fluxes of 100–300 kgm−2 s−1, saturation temperatures of 30°C–50 °C and from x = 0.05 to superheat of 50 °C in a horizontal smooth tube with 6.1 mm inner diameter. R134a is observed to have approximately 10% higher and 20% lower HTC compared to R1234ze(E) and R32 respectively. Cavallini correlation predicted the data within an accuracy of 12% while Kondo-Hrnjak correlation predicted HTC for condensation in de-superheating zone within accuracy of 23%. 相似文献