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p‐Type Optoelectronic and Transparent Conducting Oxide Properties of Delafossite CuAl1/2Fe1/2O2 下载免费PDF全文
Chesta Ruttanapun Phumin Jindajitawat Prathan Buranasiri Adul Harnwunggmoung Anek Charoenphakdee Vittaya Amornkitbamrung 《Journal of the American Ceramic Society》2015,98(2):437-442
CuAl1/2Fe1/2O2 delafossite was prepared using a solid‐state reaction method to investigate its optical and electronic transport properties. CuAl1/2Fe1/2O2 formed a hexagonal delafossite structure with an Rm space group. The positive Seebeck coefficient and the direct optical gap of 3.6 eV confirmed that the CuAl1/2Fe1/2O2 delafossite in a p‐type transparent conducting oxide. The fluorescence emission at 390 nm (green emission) confirmed that CuAl1/2Fe1/2O2 has a direct transition band gap. Thermogravimetric analysis indicated a weight loss of 1.2%, caused by the intercalation of O atoms, which produced hole carriers from the different ionic radii at the B sites. The electric conductivity at room temperature was thermally activated, as predicted by the small‐polaron hopping mechanism, with an activation energy of 75 meV and a charge transport energy of 61 meV. CuAl1/2Fe1/2O2 delafossite exhibited p‐type optoelectronic behavior and is a transparent conducting oxide, which may be crucial in the p‐type photonic and electrode industries. 相似文献
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Suksun Horpibulsuk Cherdsak Suksiripattanapong Anek Niramitkornburee Avirut Chinkulkijniwat Theerasak Tangsutthinon 《Geotextiles and Geomembranes》2011,29(5):514-524
This article presents the performance of a fully instrumented test wall reinforced with bearing reinforcement. Bearing reinforcement is an inextensible earth reinforcement. It is composed of a longitudinal member and transverse members. The longitudinal member is a deformed steel bar and the transverse members are a set of equal steel angles. The test wall was 6 m high, 9 m long at the top, 6 m wide at the top, and 12 m long, 21 m wide at the base and was constructed on a hard stratum. The facing panels were made of segmental concrete block which measured 1.50 × 1.50 × 0.14 m in dimension. From the full-scale test results, the bearing stress distribution is a trapezoid shape as generally assumed for the examination of the external stability of MSE walls. The tilt of the bearing reinforcement earth (BRE) wall indicates that the BRE wall behaves as a rigid body. The coefficients of earth pressure decrease with depth and approach the active state at deeper reinforcement level. From the variation in the stiffness factor as a function of depth and lateral earth pressure, the bearing reinforcement has a stiffness factor of K/Ka = 1.7, which is much lower than that of steel grids and metal strips. The lower tension (coefficient of lateral earth pressure) reduces the cross-sectional area of the longitudinal members and hence cost effectiveness. The maximum tension line (possible failure plane) of the BRE wall is bilinear, similarly to the coherent gravity structure hypothesis, which is commonly used for the analysis of inextensible reinforcements. Finally, the suggested method of designing the BRE wall is presented. It has been successfully used to design several BRE walls founded on the hard stratum in different areas in Thailand. 相似文献
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Clifford A. Hughes Colin G. Taylor Anek Thamaung 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1983,33(7):381-386
The fungicides, 3,5-dimethyltetrahydro-1,3,5-thiadiazine-2-thione (DTTT) and 4-tolyldiiodomethylsulphone (TDMS) have been prepared labelled with 14C and incorporated into polyvinylacetate emulsion (PVA), styrene/acrylic emulsion (acrylic) or alkyd gloss (alkyd) paints. Test plates prepared from these paints have been exposed in both tropical and temperate conditions and losses of fungicides have been followed radiometrically. In outdoor conditions, DTTT is rapidly lost from all the paints. Indoors, DTTT is retained well (50% after 150 days) only by alkyd paint. TDMS is well retained in indoor conditions by all the paints. Outdoors however, retention in PVA and acrylic films is less than 50% after 150 days and is poorer in tropical conditions. About 90% of the TDMS is retained in alkyd films for an indefinite period in temperate conditions: in tropical conditions, 80% is retained after 150 days. Comparisons of losses from paint films of mercurial and non-mercurial fungicides show that TDMS is a satisfactory substitute for the more commonly used mercurials. 相似文献
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S. Yamanaka M. Ishimaru A. Charoenphakdee H. Matsumoto K. Kurosaki 《Journal of Electronic Materials》2009,38(7):1392-1396
The key properties for the design of high-efficiency thermoelectric materials are a low thermal conductivity and a large Seebeck
coefficient with moderate electrical conductivity. Recent developments in nanotechnology and nanoscience are leading to breakthroughs
in the field of thermoelectrics. The goal is to create a situation where phonon pathways are disrupted due to nanostructures
in “bulk” materials. Here we introduce promising materials: (Ga,In)2Te3 with unexpectedly low thermal conductivity, in which certain kinds of superlattice structures naturally form. Two-dimensional
vacancy planes with approximately 3.5-nm intervals exist in Ga2Te3, scattering phonons efficiently and leading to a very low thermal conductivity. 相似文献
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Mechanically stabilized earth (MSE) structure has been widely accepted as a retaining structure. Its construction cost is mainly controlled by backfill materials, which are generally coarse-grained soils, and reinforcement type (steel volume). The present paper introduces a new cost-effective reinforcement, designated as “Bearing Reinforcement”. It is composed of a longitudinal member and transverse (bearing) members. The longitudinal member is made of a deformed bar, which exhibits a high pullout friction resistance. The transverse members are a set of equal angles, which provide high pullout bearing resistance. The maximum pullout bearing resistance of a single isolated transverse member, σbmax, can be determined by using the plasticity solution based on the modified punching shear failure mechanism. Influential factors governing the mobilization of pullout bearing resistance are spacing, S, leg length, B, and numbers, n of transverse members. The larger the S/B, the lower the transverse member interference. The S/B ratios of <3.75 and >25 are referred to as full and free interference, respectively. The relationship between normalized average pullout bearing stress, σbn/nσn and pullout displacement, d, where σbn/n is average pullout bearing stress of the bearing reinforcement with n transverse members and σn is applied normal stress, is practically identical for the same level of transverse member interference. This relationship can be modelled by hyperbolic function. From this finding, a suggested procedure for estimating pullout characteristics (maximum pullout resistance and pullout force versus displacement relationship) of the bearing reinforcement for any level of transverse member interference (any S, B, and n) based on a one point test on the bearing reinforcement with a single isolated transverse member is proposed. Good agreement has been obtained between the predicted and the measured pullout characteristics. This suggested method is useful for the internal stability analysis of MSE wall in terms of engineering and economic viewpoints. 相似文献
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Chesta Ruttanapun Aree WichainchaiWutthisak Prachamon Anucha YangthaisongAnek Charoenphakdee Tosawat Seetawan 《Journal of Alloys and Compounds》2011,509(13):4588-4594
The samples of Cu1−xPtxFeO2 (0 ≤ x ≤ 0.05) delafossite were synthesized by solid state reaction method for studying thermoelectric properties. The properties of Seebeck coefficient, electrical conductivity and thermal conductivity were measured in the high temperature ranging from 300 to 960 K. The results of Seebeck coefficient, electrical conductivity and power factor were increased with increasing Pt substitution and temperature. The thermal conductivity was decreased from 5.8 to 3.5 W/mK with increasing the temperature from 300 to 960 K. An important results, the highest value of power factor and ZT is 2.0 × 10−4 W/mK2 and 0.05, respectively, for x = 0.05 at 960 K. 相似文献
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Atsuko Kosuga Ken Kurosaki Kunio Yubuta Anek Charoenphakdee Shinsuke Yamanaka Ryoji Funahashi 《Journal of Electronic Materials》2009,38(7):1303-1308
We have focused on the recently reported nanostructured bulk ZnMn2−x
Ga
x
O4 to evaluate whether this type of nanostructured oxide can effectively reduce thermal conductivity. Firstly, powdered samples
of ZnMn2−x
Ga
x
O4 (x = 0 to 2) were prepared and the effect of heat treatment on the obtained phases was examined. Secondly, we have picked out
the composition of ZnMnGaO4, in which two distinct types of rectangular nanorods with different compositions spontaneously interlace to form a cross-sectional
checkerboard pattern. To confirm the effect of nanostructure on thermal transport properties, the room-temperature thermal
conductivity of this nanostructured oxide was evaluated. 相似文献
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