Piezoelectric composites of PZT ceramics and several semi-crystalline polymers have been produced by embedding slender PZT rods (4 volume percent) in the polymers. The observed dielectric constants were considerably l...
Piezoelectric composites of PZT ceramics and several semi-crystalline polymers have been produced by embedding slender PZT rods (4 volume percent) in the polymers. The observed dielectric constants were considerably lower than that of pure PZT. The hydrostatic piezoelectric voltage coefficients of the composites were larger than PZT, even though the composite hydrostatic piezoelectric strain coefficients were lower. Composite figures of merit ranged from one-third to six times that of PZT.
Lithium batteries have been essential technologies and become an integral part of our daily lives, powering a range of devices from phones to electric vehicles. To fully understand and optimize the performance of lith...
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Lithium batteries have been essential technologies and become an integral part of our daily lives, powering a range of devices from phones to electric vehicles. To fully understand and optimize the performance of lithium batteries, it is necessary to investigate their internal states and processes through various characterization methods. Neutron imaging has been an indispensable complementary characterization technique to X-ray imaging or electron microscopy because of the unique interaction principle between neutrons and matter. It provides particular insights into the various states of matter inside lithium batteries,including the Li+concentration in solid electrodes, the Li plating/stripping behavior of Li-metal anodes,the Li+diffusion in solid ionic conductors, the distribution of liquid electrolytes and the generation of *** review aims to highlight the capabilities and advantages of neutron imaging in characterizing lithium batteries, as well as its current state of application in this field. Additionally, we discuss the potential of neutron imaging to contribute to the ongoing development of advanced batteries through its ability to visualize internal evolution.
A method for reduction of detailed chemical reaction mechanisms, introduced earlier for ignition systems, was extended to laminar premixed flames. The reduction is based on testing the reaction and reaction-enthalpy r...
A method for reduction of detailed chemical reaction mechanisms, introduced earlier for ignition systems, was extended to laminar premixed flames. The reduction is based on testing the reaction and reaction-enthalpy rates of the "full" reaction mechanism using a zero-dimensional model with a flame temperature profile as a constraint. The technique is demonstrated with numerical tests performed on the mechanism of methane combustion.
The microstructure features, martensitic transformation behavior and mechanical/functional properties of Ti–V–Al alloy were tailored by changing rare element Y content in the present investigation. The results showe...
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The microstructure features, martensitic transformation behavior and mechanical/functional properties of Ti–V–Al alloy were tailored by changing rare element Y content in the present investigation. The results showed that Y doping resulted in the grain refinement and formation of Y-rich phase mainly distributing along grain boundary in Ti–V–Al alloys. The martensitic transformation temperatures of Ti–V–Al alloys slightly increased due to the variation of matrix composition induced by the presence of Y-rich phase. The mechanical and functional properties of Ti–V–Al alloys doped moderate Y addition were significantly improved, which can be ascribed to grain refinement, solution strengthening and precipitation strengthening. The 1.0 at.%Y-doped Ti–V–Al alloy exhibited the highest ultimate tensile stress of 912 MPa and largest elongation of 17.68%. In addition, it was found that the maximum recoverable strain of 5.42% can be obtained in Ti–V–Al alloy with adding 1.0 at.%Y,under the pre-strain of 6% condition, which is enhanced by approximate 0.6% than that of Ti–V–Al alloy without Y addition.
Quantum fluctuations are pivotal in driving quantum phase transitions, exemplified by the quantum melting of Wigner crystals into Fermi liquids in electron systems. However, their impact on superconducting systems nea...
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An economical postprocessing method for estimating feature sensitivity coefficients is presented;This method uses precomputed elementary sensitivity coefficients calculated by standard methods to obtain a perturbed so...
An economical postprocessing method for estimating feature sensitivity coefficients is presented;This method uses precomputed elementary sensitivity coefficients calculated by standard methods to obtain a perturbed solution using a linear approximation to the Taylor series expansion. The perturbed solution is then used for simple feature sensitivity calculations. This approach avoids costly repetitive integrations for each model parameter and can be readily implemented with available computer codes which solve for species profiles and elementary sensitivities. The method was tested using a practical example of a CH name profile and shown to be in good agreement with a brute-force sensitivity analysis performed for the same conditions. It is also suggested that the method can be readily extended to simultaneous sensitivity analysis of multiple responses or to sensitivity analysis with respect to a functional combination of model parameters. (C) 1995 John Wiley & Sons, Inc.
The relative magnitude of the equilibrium constants describing self-association versus inter-association is an important factor in determining the phase behavior of polymers that hydrogen bond. In studies of stericall...
The relative magnitude of the equilibrium constants describing self-association versus inter-association is an important factor in determining the phase behavior of polymers that hydrogen bond. In studies of sterically hindered phenolics we have found that poly(2,6-diisopropyl-4 vinylphenol) (PDIPP) only moderately self-associates, but strongly inter-associates with polymers containing groups such as ester carbonyls, ether oxygens, and the like. PDIPP is miscible with polytetrahydrofuran (PTHF) and simultaneously acts as an efficient polymeric antioxidant. This result points the way to the design of specific miscible polymeric antioxidants for polar polymers.
Accurate parameterization of theoretical unimolecular rate coefficients into simple analytical expressions is an important requirement for effective modeling of large chemical kinetic systems. Currently available para...
Accurate parameterization of theoretical unimolecular rate coefficients into simple analytical expressions is an important requirement for effective modeling of large chemical kinetic systems. Currently available parameterization schemes predict rate coefficients that could deviate from the ''exact'' theory by as much as a factor of two. It is suggested in this study to replace the Lorentz-type pressure broadening of Troe's fall-off formula for unimolecular rate coefficients with a Gaussian form. Numerical tests were performed for several decomposition reactions over wide ranges of pressure and temperature using ''rigid'' RRKM calculations and solutions of master equations. The results demonstrate that the use of Gaussian broadening improves substantially the accuracy of Troe's formula.
The application of all-solid-state Li-metal batteries with solid oxide electrolytes is hindered by interfacial issues,especially the solid electrolyte/Li-metal *** work introduced a uniform indium film layer on the su...
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The application of all-solid-state Li-metal batteries with solid oxide electrolytes is hindered by interfacial issues,especially the solid electrolyte/Li-metal *** work introduced a uniform indium film layer on the surface of Na^(+)super ionic conductor(NASICON)solid electrolyte Li_(1.5)Al_(0.5)Ge_(1.5)P_(3)O_(12)(LAGP),which promotes the intimate contact between Li metal and solid electrolyte and hinders the side reactions at the *** impedance spectra show that the battery with coated solid electrolyte presents a smaller interfacial resistance and maintains stability after a long cycling *** contrast,the baseline battery with a pure LAGP pellet shows a contact loss after cycling with the vibration of interfacial *** Li symmetric cells with indium-modified solid electrolyte present stable cycling behavior over 400 h at 0.1 and 0.2 mA·cm^(−2).The all-solid-state Li-metal batteries with a Li anode,indium coating LAGP and two kinds of cathodes,namely carbon nanotubes(CNTs)and LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811),are prepared and *** CNTs cathode for Li-O2 and Li-air batteries has a higher specific capacity than traditional Li-ion battery *** Li-NCM811 batteries deliver an initial Coulombic efficiency of about 75%,with 82%capacity retention after 20 cycles.
The use of polysaccharides in drug delivery systems has attracted increasing interest due to their functional properties. Among these, alginate (ALG) and chitosan (CH) are promising candidates for sustained drug deliv...
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