On Error Bounds for Quasinormal Programs

The Mangasarian-Fromovitz constraint qualification is a central concept within the theory of constraint qualifications in nonlinear optimization. Nevertheless there are problems where this condition does not hold though other constraint qualifications can be fulfilled. One of such constraint qualifications is the so-called quasinormality by Hestenes. The well known error bound property (R-regularity) can also play the role of a general constraint qualification providing the existence of Lagrange multipliers. In this note we investigate the relation between some constraint qualifications and prove that quasinormality implies the error bound property, while the reciprocal is not true.     

Controlled collective acceleration of electron-ion bunches

The fundamental possibility of a new method for controlled collective ion acceleration by electron bunches of high-current relativistic picosecond beams has been proved. Dense relativistically rotating electron bunches are formed using a cusp magnetic system by their capture in a special magnetic trap. An electron bunch is filled with ions when it interacts with a preliminarily prepared plasma bunch with a certain density. Then, the effective potential well of the magnetic trap is stepwise shifted synchronously with the motion of ions by means of a system of turns with controlled currents. This ensures the displacement and confinement of electrons in the direction of acceleration. The shift of the center of the well at each step is chosen such that ions are in the region of acceleration by a high self electric field of the electron bunch. In contrast to the known methods for collective acceleration, the proposed method makes it possible to avoid the mismatch of the electron and ion components of bunches, disruption of the acceleration of ions, and development of numerous instabilities, because the duration of the acceleration cycle is in the nanosecond range.     

Relativistic twistron based on backward-wave oscillator with modulating reflector and an efficiency of 56%

Technical Physics - Using numerical simulation, the operating mode of a relativistic Cherenkov microwave generator of the twistronic type has been demonstrated. The generator includes an...     

Evidence for double acoustic windows in the dolphin, Tursiops truncatus

In a bottlenose dolphin positions of sound receiving areas on the head surface were determined by comparing the acoustic delays from different sound-source positions. For this investigation, auditory brainstem responses (ABRs) to short tone pips were recorded and their latencies were measured at different sound source positions. After correction for the latency dependence on response amplitude, the difference in ABR latencies was adopted as being the difference of the acoustic delays. These delay differences were used to calculate the position of the sound-receiving point. Measurements were conducted at sound frequencies from 16 to 128 kHz, in half-octave steps. At probe frequencies of 16 and 22.5 kHz, the receiving area was located 21.7-26 cm caudal of the melon tip, which is near the bulla and auditory meatus. At higher probe frequencies, from 32 to 128 kHz, the receiving area was located from 9.3 to 13.1 cm caudal of the melon tip, which corresponds to a proximal part of the lower jaw. Thus, at least two sound-receiving areas (acoustic windows) with different frequency sensitivity were identified.     

Quantum-chemical investigation of some oligomeric heteroaromatic compounds

The characteristics of the electronic structures of a number of model aromatic oxazoles realized in aromatic polyoxazoles were obtained within the framework of the Pariser-Parr-Pople method. The UV spectra of most of them were interpreted. The stereoisomerism of dibenzoxazoles is examined.     

Generation of high-power ultrawideband electromagnetic pulses in a system with a coaxial tem horn

A coaxial TEM horn was designed on the basis of results from nonstationary computer modeling using code KARAT. With its high dielectric strength, this antenna is capable of radiating high-power ultrawideband nanosecond pulses. The pulse source used was a compact generator built around a coaxial forming line with a built-in Tesla transformer, which shapes pulses up to 1 GW high at repetition frequencies up to 1 kHz. The amplitude of the pulses on a matched load was 20 kV at a duration of 4 nsec. Returns of ultrawideband signals from objects with simple geometric shapes were studied in laboratory experiments using this radiator. Institute of High-Current Electronics, Siberian Division, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 110–118, December, 1996.