A Study of Online Portal Users’ Loyalty From Core Service,Additional Value-added Service and Switching Barriers Perspectives

This study proposes a research model elucidating the effects of core service satisfaction, additional value-added service satisfaction, and switching barriers as determinants of portal loyalty and tests the model using empirical data collected from game portal users. The results suggest that different service satisfaction and switching barriers are strong antecedents of p-loyalty; the moderating effect of switching barriers on the relationship between satisfactions and p-loyalty is contingent on the portal users’ usage patterns.     

Japan Flavour and Fragrance Materials Association’s (JFFMA) safety assessment of food-flavouring substances uniquely used in Japan that belong to the class of aliphatic primary alcohols,aldehydes, carboxylic acids,acetals and esters containing additional oxygenated functional groups

ABSTRACT

We performed a safety evaluation using the procedure devised by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) of the following four flavouring substances that belong to the class of ‘aliphatic primary alcohols, aldehydes, carboxylic acids, acetals, and esters containing additional oxygenated functional groups’ and are uniquely used in Japan: butyl butyrylacetate, ethyl 2-hydroxy-4-methylpentanoate, 3-hydroxyhexanoic acid and methyl hydroxyacetate. Although no genotoxicity study data were found in the published literature, none of the four substances had chemical structural alerts predicting genotoxicity. All four substances were categorised as class I by using Cramer’s classification. The estimated daily intake of each of the four substances was determined to be 0.007–2.9 μg/person/day by using the maximised survey-derived intake method and based on the annual production data in Japan in 2001, 2005 and 2010, and was determined to be 0.250–600.0 μg/person/day by using the single-portion exposure technique and based on average-use levels in standard portion sizes of flavoured foods. Both of these estimated daily intake ranges were below the threshold of toxicological concern for class I substances, which is 1800 μg/person/day. Although no information from in vitro and in vivo toxicity studies for the four substances was available, these substances were judged to raise no safety concerns at the current levels of intake.     

Infiltrated La0.5Ba0.5CoO3-δ in La0.8Sr0.2Ga0.8Mg0.2O2.8 scaffolds as cathode material for IT-SOFC

The electrochemical response of infiltrated La_0.5Ba_0.5CoO_3-δ (LBC) in porous La_0.8Sr_0.2Ga_0.8Mg_0.2O_2.8 (LSGM) has been investigated. The thermal expansion coefficient (TEC) of the resulting electrode was measured, obtaining α?=?12.5?×?10^?6 K^?1, a value similar to that of LSGM. The polarization resistance (Rp) and the processes involved in the oxygen reduction reaction (ORR) for the new electrode were studied and analyzed through complex impedance spectroscopy measurements as a function of temperature and oxygen partial pressure (pO₂), using a symmetrical cell. The value of Rp for the infiltrated LBC turned out to be lower than that measured for an electrode prepared with a composite LBC-LSGM (1:1?wt%) by an order of magnitude, for the temperature range 750?°C ≤ T?≤?900?°C, and about 5 times lower for the temperature range 450?°C≤ T?≤?650?°C. At 600?°C, the LBC infiltrated cathode exhibits a polarization resistance R_p =?0.22?Ω?cm², in air. The complex impedance spectra show two processes, one identified as low frequency (LF),with a characteristic frequency of 10?Hz, and the other as intermediate frequency (IF), with a range between 0.05 and 2000?Hz. The LF process could be associated to the diffusion of oxygen in the gas phase through the pores of the electrode. Its resistance, R_LF =?0.01?Ωc?m²_, was found to be independent of the temperature and half of that obtained for the LBC composite cathode. On the other hand, the IF process is related to charge transfer at the electrode surface and the electrode-electrolyte interface. The LBC cobaltite infiltrated in the LSGM scaffolds offers an adequate thermal expansion coefficient and good electrocatalytic activity for the ORR.     

Structure and transport properties of the spark plasma sintered barium cerate based proton conductor

BaCe_0.7Y_0.2In_0.1O_3–δ (BCYI) compositions were prepared by a modified Pechini method, following this the ceramic samples were consolidated using conventional sintering (CS) and spark plasma sintering (SPS) at 1250–1500 °C for 3–10 min. The structural and microstructural characteristics of the samples were determined using XRD, SEM and TEM. The total, bulk and grain boundary ionic conductivities were evaluated using the AC impedance method in dry air, wet air and dry Ar. It was shown that application of SPS in case of nanocrystalline BCYI allows to reduce the sintering time, and in case of microcrystalline BCYI application of SPS after CS allows to improve hardness and total conductivity through reduction of grain boundary resistance.     

Electronic Granularity and the Work Function of Transparent Conducting ZnO:Al Thin Films

Controlling the efficiency of electron transport across oxide interfaces is essential for numerous emerging technologies including advanced photovoltaics and light emitting devices. This work illuminates the connections between granular structure, defect chemistry, and the work function of a technologically important transparent conductor, ZnO:Al. Visual evidence is provided for a model of grain boundary oxidation in the form of nanometer‐scale heterogeneity in the contact potential between grains and grain boundaries, a phenomenon referred to as electronic granularity. By correlating scanning probe data with photoemission spectroscopy we relate electronic granularity to defect chemistry and, importantly, account for the overall trends in work function. The resulting physical picture connects heterogeneity at the nanoscale to macroscopic properties, informs the design of transparent electrodes, and may be broadly relevant to granular oxide conductors.     

参量回归与指数函数曲线拟合

本文讨论了一种带参量的多项式回归拟合。调节参量数值可使剩差平方和达到足够小,从而减省了所用的项数。通过变换又可导致指数函数曲线拟合。这对某些问题(尤其如热传导问题等)具有简化计算或求解的作用。     

厚表土层中竖井沥青夹层复合井壁的试验研究

以相似理论为基础，用模拟试验研究了有沥青夹层的复合井壁，得到了沥青夹层的适宜厚度，传递竖直附加力的规律和数值；同时研究了外层井壁的可压缩层材料，获得可压缩层材料与传递到内层井壁的竖直附加力的关系。     

广西天湖水电站压力管道镇支墩位移监测研究

高水头水电站压力管道及其镇支墩的稳定和安全至关重要，安全监测应以镇支墩位移为主。观测精度指标的选取要依据管道结构本身对镇支墩位移的实际承受能力来确定，在天湖水电站，其观测中误差允许值，镇墩纵向位移取１．６ｍｍ，镇支墩间沉降差取０．４ｍｍ。     

Specific Heat and Electrical Resistivity of 53%Niobium-47%Titanium Alloy Measured by Subsecond Calorimetric Technique

This paper presents results of measurements of the specific heat and electrical resistivity of a 53%Ni-47%Ti superconducting alloy. Both properties were measured by a contact variant of the millisecond-resolution pulse calorimeter. W5%Re/W25%Re thermocouple thermometry enabled study from ambient temperature to 2000 K. Results are discussed, and their uncertainty is estimated.