Measurement of piezoelectric modulus by pulsed excitation of piezoelectric ceramic elements

The possibility of measuring the piezoelectric modulus by exciting piezoelectric ceramic components with a radio pulse is considered. It is shown that there is a relation between the piezoelectric modulus and the rate of change of the current envelope at the beginning of the transient. Theoretical relations are derived. __________ Translated from Izmeritel’naya Tekhnika, No. 10, pp. 71–72, October, 2006.     

Determination of the parameters of piezoceramic elements from amplitude measurements

A new method of measuring the parameters of a piezoceramic element is proposed, the basis of which is the maximum values of the amplitudes of the conductance and its derivative. The method only requires simple automated instruments.     

用于激光起爆的新型光敏炸药——过氯酰胺(英)

介绍了过氯酰胺盐的一些性质,指出过氯酰胺盐是激光起爆阈值低的光敏炸药。用１０％光学透明的聚合物分别５０ｍｇ／ｃｍ＾２的过氯酰胺钾和过氯酰胺钡制１ｃｍ＾２的光敏炸药薄板并进行了实验。Ⅱ的起爆阈值经久０．１Ｊ／ｃｍ＾２,Ⅳ的起爆阈值为５－７ｍＪ／ｃｍ＾２,皆低于压装的叠氮化铅药柱,全都实现了平面起爆。     

Operation algorithm of reference model-based adaptive system ensuring given dynamic precision of control of nonstationary dynamic object under uncertainty

A new adaptation algorithm was proposed for reference model-based systems operating independently of the intensity and spectral composition of the input actions. This fact enables one to make predictable the dynamic precision of the reference model-based adaptive system which, by the authors’ opinion, is the stumbling block to wide practicalization of the systems of the class under consideration.     

Determining Piezoceramic Parameters on Disks

Approximate formulas are obtained for various parameters of a piezoelectric material in the form of a disk, which do not require the calculation of the least (first) root of the frequency equation. To calculate approximately the planar electromechanical coupling coefficient, one can simplify the measurement procedure because it is not necessary to measure the first overtone frequency and determine Poisson's ratio.     

Integrated sensor array for analysis of multicomponent gas mixtures

A new device has been proposed and tested experimentally for the discrimination of gases in “electronic nose” systems. The device consists of an array of surface-acoustic wave (SAW) sensors positioned on a single anisotropic substrate with a common gas-sensitive coating for each sensor. The specificity of the sensors is provided entirely by the elastic anisotropy of the single-crystal substrate: changes in the direction of propagation of the wave through the gas-sensitive film deposited on the anisotropic substrate are accompanied by changes in the partial components of the mechanical displacement of the wave and corresponding contributions to the resultant SAW “response.” Pis’ma Zh. Tekh. Fiz. 24, 40–45 (August 26, 1998)