This paper examines the nonlinear electromechanical response of 1-3 piezoelectric/polymer composites. The piezocomposites contain square or circular piezoelectric rods in an epoxy matrix. Experiments were conducted to measure the displacement versus electric field curves, using the device specimen of the 1-3 piezocomposites. Three dimensional finite element analysis was also carried out to study the electromechanical fields in the 1-3 piezocomposites by introducing a model for polarization switching. Comparison was then made between simulation and experiment. 相似文献
We describe features of our methodology for predicting tertiary structures (i.e., conformations) of proteins in solvent just from the amino-acid sequences and molecular models for the solvent. The methodology, which is a combination of the Monte Carlo simulated annealing technique and the reference interaction site model theory, is illustrated for the small peptides, Met-enkephalin and C-peptide. Important roles played by water are discussed, and the alcohol effects on peptide conformations are newly analyzed. 相似文献
We extend the molecular theory of the solvated electrons [Chandler, Singh and Richardson, J. Chem. Phys. 81, 1975 (1984)] to calculate the density matrix for an excess electron in water. Using this density matrix, the numerically obtained solvent induced interaction [Miura and Hirata, J. Phys. Chem. 98, 9649 (1994)] and our developed method [Sethia, Sanyal and Singh, J. Chem. Phys. 93, 7268 (1990)], we have calculated the eigenstates of the electron in water. These results show that the excees electron in water behaves almost like a free particle with effective mass m* in a constant potential well. 相似文献
Summary. Interpolation error estimates for a modified 8-node serendipity finite element are derived in both regular and degenerate
cases, the latter of which includes the case when the element is of triangular shape. For defined over a quadrilateral K, the error for the interpolant is estimated as
, where in the regular case and in the degenerate case, respectively. Thus, the obtained error estimate in the degenerate case is of the same quality as
in the regular case at least for . Results for some related elements are also given.
Received June 2, 1997 / Published online March 16, 2000 相似文献
Summary: 2,2,6,6‐Tetramethylpiperidine 1‐oxyl (TEMPO)‐containing N‐propargylamide HCCCH2NHCO‐4‐TEMPO ( 1 ), propargyl ester HCCCH2OCO‐4‐TEMPO ( 2 ), phenylacetylene derivative HCCC6H3‐3,4‐(CO2‐4‐TEMPO)2 ( 3 ), and norbornene diester monomers, NB‐2,3‐exo,exo‐(CH2OCO‐4‐TEMPO)2 ( 4 ), NB‐2,3‐endo,exo‐(COO‐4‐TEMPO)2 ( 5a ), NB‐2,3‐endo,endo‐(COO‐4‐TEMPO)2 ( 5b ) (NB = norbornene, TEMPO = 2,2,6,6‐tetramethyl‐1‐piperidinyloxyl) were synthesized and polymerized with rhodium and ruthenium catalysts. Monomers 2 , 5a , and 5b gave polymers with number‐average molecular weights of 47 000–185 000 in 59–100% yields, while 1 , 3 , and 4 gave polymers insoluble in common organic solvents in 88–100% yields. The capacities of cells fabricated with poly( 1 ), poly( 2 ), and poly( 3 ) were 67, 82, and 23 Ah · kg−1 based on the weight, respectively. The capacity of poly( 5a )‐based cell reached the theoretical value (109 Ah · kg−1) of the polymer.
Charge–discharge curves of poly( 5a ) at a current density of 0.13 mA · cm−2 (100 mA · g−1‐cathode active material) in the voltage range of 2.5–4.2 V. 相似文献