Stretchable energy storage devices,maintaining the capability of steady operation under large mechanical strain,have become increasing more important with the development of stretchable electronic *** supercapacitors(...
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Stretchable energy storage devices,maintaining the capability of steady operation under large mechanical strain,have become increasing more important with the development of stretchable electronic *** supercapacitors(SSCs),with high power density,modest energy density,and superior mechanical properties are regarded as one of the most promising power supplies to stretchable electronic *** polymers,such as polyaniline(PANI),polypyrrole(PPy),polythiophene(PTh)and poly(3,4-ehtylenedioxythiophene)(PEDOT),are among the well-studied electroactive materials for the construction of SSCs because of their high specific theoretical capacity,excellent electrochemical activity,light weight,and high *** effort has been devoted to developing stretchable,conductive polymer-based SSCs with different device structures,such as sandwich-type and fiber-shaped type *** review summarizes the material and structural design for con ductive polymer-based SSCs and discusses the challenge and importa nt di recti ons in this emergi ng field.
Yellow-emitting BCNO phosphors,applied for white light-emitting-diodes（LEDs）,were synthesized by a facile microwave heating route at lower temperature within short *** prepared BCNO phosphors exhibited amorphous for...
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Yellow-emitting BCNO phosphors,applied for white light-emitting-diodes（LEDs）,were synthesized by a facile microwave heating route at lower temperature within short *** prepared BCNO phosphors exhibited amorphous form and tunable yellow emission in the range of 510–550 nm under the excitation of 450-nm blue *** effects of carbon content on the photoluminescence properties for these BCNO phosphors and their application performances in white LEDs were investigated in *** demonstrated microwave synthesis route is promising in preparing low-cost phosphors,and the prepared BCNO phosphor may find potential application in blue-based white LEDs.
The partial pressures of , , and are determined for the solid solutions with and for y values corresponding to Pb‐Sn saturation, to Te saturation, and to compositions within the homogeneity range, as well as for the ...
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The partial pressures of , , and are determined for the solid solutions with and for y values corresponding to Pb‐Sn saturation, to Te saturation, and to compositions within the homogeneity range, as well as for the liquids forming from these solids. The partial pressures are extracted from measurements of the optical absorbance of the coexisting vapor phase between 230 and 700 nm. A number of thermodynamic and phase diagram data are obtained. The enthalpy of fusion of congruently melting, 50.4 a/o Te , is . Combining our data with published data, the high temperature Gibbs energy of formation is obtained for compositions between 50.1 and 50.9 a/o Te and for all of these, and . Comparing our data with 77 K Hall measurements, the native acceptors are doubly ionized for . The Gibbs energy of formation of the solid solutions from the binary compounds is close to, but distinct from, the value for the ideal mixing of and. In contrast the enthalpy and excess entropy of mixing are not closely defined and their 95% confidence level uncertainties include the value zero. The partial pressure of for the 50 a/o Te melts is independent of the x‐value.
An experimental method was devised to increase the "packing density" of random spherical powder packings by agitation with an applied compressive force. Maximum random packing densities of both monosize and ...
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An experimental method was devised to increase the "packing density" of random spherical powder packings by agitation with an applied compressive force. Maximum random packing densities of both monosize and bimodal-size powder packings of various size ratios and volume fractions are compared to the as-received gas-atomized SS316L powder. Since the presence of a compressive load will tend to restrict the opening of interparticle passages through the powder pack, uniform mixing of the powders beforehand is important for achieving optimum packing. At the same time, however, macroscopic size segregation of mixer-mill-premixed powder packings was found not to be significant using this technique. Densities of optimized bimodal-size powder packings far exceed those of non-optimized packings and the as-received (continuously distributed) powder. This enhancement is also retained during subsequent hot isostatic pressing.
Two-point bending is a useful method for investigating the mechanical properties of optical fiber and has several advantages when compared to the traditional tensile test. However, the strength of the fiber is usually...
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Two-point bending is a useful method for investigating the mechanical properties of optical fiber and has several advantages when compared to the traditional tensile test. However, the strength of the fiber is usually determined at constant faceplate velocity rather than at constant strain rate as in the uniaxial tensile test, and previous work casts doubt on the comparability of fatigue results obtained using different loading modes and hence on the reliability of the bending technique. This paper presents dynamic fatigue results using a two-point bend apparatus that can be programmed to operate in constant velocity, constant strain rate, and constant stress rate loading modes. These results, obtained for both bare and polymer-coated fused silica optical fiber, show no significant differences in the calculated fatigue parameters for the three loading modes and clearly indicate the reliability of the two-point bend method at constant faceplate velocity. The results, however, show that the obtained value of the stress corrosion susceptibility parameter, n, is dependent on the quantity used to define it, i.e., stress or strain to failure, because of the nonlinear elastic behavior of silica.
The optical absorbance of the vapor over pure Te, over Pb‐Te samples containing 49.01, 49.70, 51.26, and 55 atom percent (a,o) Te, and over a 1.56 mg crystal of is measured between 230 and 700 nm for optical cell tem...
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The optical absorbance of the vapor over pure Te, over Pb‐Te samples containing 49.01, 49.70, 51.26, and 55 atom percent (a,o) Te, and over a 1.56 mg crystal of is measured between 230 and 700 nm for optical cell temperatures of 1028, 1133, 1273, and 1353 K, and for a range of sample temperatures. The partial pressures of , , and of are extracted from the data. For Te‐saturated , reaches a maximum value of between 1064 and 1099 K and drops to at the 1197 K maximum melting point. increases monotonically with T for Pb‐saturated and is the minimum measurable value of at 1117 K. The partial pressure of , , is determined between 1000 and 1353 K and is at 1197 K. The enthalpy of fusion of deduced from the temperature dependence of . The standard Gibbs energy of dissociation of into Pb(g) and is determined from 1000 up to 1197 K, where it is 79.445 kJ/mol. Combining with the published chemical potentials for Pb and liquidus temperatures for various melt compositions and with published heat capacity data allow a determination of the standard Gibbs energy, enthalpy, and entropy of formation of . At 298 K the latter two quantities are, respectively, and .
The partial pressures of Hg, Cd, and have been determined between 420° and 840°C from optical absorption measurements for four Te‐rich compositions and for the Te‐saturated solid solution with . In additio...
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The partial pressures of Hg, Cd, and have been determined between 420° and 840°C from optical absorption measurements for four Te‐rich compositions and for the Te‐saturated solid solution with . In addition to further thermodynamically characterizing the melt, the former measurements yield ternary liquidus points. They also yield tie lines when combined with the present and previous measurements on Te‐saturated solid solutions. These results, from an essentially steady‐state technique, agree well with those of Harman. The measurements on the solid solutions yield values for the mixing quantities which are more accurate than our previous values. These are described well in terms of a quasi‐regular solution of and components with an enthalpy of mixing of 1074 cal/g‐atom and an excess entropy of mixing of 0.893 cal/K‐g‐atom at 50 mole percent .
This study investigated the long-term durability of the interfacial bond in carbon fiber polyetheretherketone (C/PEEK) and carbon fiber/polysulfone (C/PSF) composites after exposure to hygrothermal environments. A sin...
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This study investigated the long-term durability of the interfacial bond in carbon fiber polyetheretherketone (C/PEEK) and carbon fiber/polysulfone (C/PSF) composites after exposure to hygrothermal environments. A single fiber pull-out test was utilized to quantitatively determine the ultimate bond strength (UBS) of the samples following exposure. Samples were tested at three temperatures for six time periods and in two environments (dry and salt water). A mathematical model based on nth order chemical reaction kinetics was applied to describe the long-term durability of the interface. The results of this study indicate that interfacial bond strength in C/PSF and C/PEEK (380 grade) composites is significantly influenced by long-term exposure to salt water, especially at high temperatures. The results indicate that salt water saturation reduces interfacial bond strength in C/PSF and C/PEEK (380 grade) composites as a function of both time and temperature, with bond strength apparently reaching a stable temperature-dependent equilibrium level.
Globally, dental caries remains a health concern due to their complications of pain, infection, and tooth loss. The traditional dental remineralization by using fluoride is effective but limited in advanced caries and...
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