Quantum effects in a one-dimensional magnetic gravitational trap for ultracold neutrons

JETP Letters - The problem of storing ultracold neutrons over a plane magnetic mirror in the presence of gravity is considered. For neutrons with a definite polarization, the sum of the magnetic...     

Low-frequency internal friction in complex composite strands

Conclusion A method was proposed which makes it possible to study the low-frequency internal friction of complex fibers. This method was used to study the internal friction of complex composite fibers based on PCA and PE. We observed a relaxation process which is typical of the composite and is absent in the pure materials.Translated from Mekhanika Kompozitnykh Materialov, No. 1, pp. 11–15, January–February, 1989.     

Aftereffect in microhardness testing of corundum

Cleavage near microhardness indentations on the surface of corundum is found to appear long (20–30 days) after unloading.     

Correlation NMR spectroscopy of 1,1-dichloro-2,3,4,5-tetraphenyl-1-germacyclopenta-2,4-diene

Assignment of all of the signals in the¹H and¹³C NMR spectra of 1,1-dichloro-2,3,4,5-tetraphenyl-l-germacyclopenta-2,4-diene has been carried out using two-dimensional NMR spectroscopy. Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 3, pp. 623–625, March, 1997.     

Crystal Structure of HAsUO6 4H2O

The crystal structure of HAsUO₆ 4H₂O was solved at 295 K by X-ray analysis. Reasons for structural changes due to temperature variation are analyzed.     

Can the optically uniaxial crystal be made optically isotropic?

A problem of variation in the refractive indices of the optically uniaxial crystal during its elastic deformation has been considered. The stress has been applied along the optical axis of the crystal. It has been shown that, under uniaxial compression of corundum and quartz, refractive indices of the ordinary and extraordinary rays converge but cannot be equal to each other.     

Latin squares over Abelian groups

In this paper, parametric families of Latin squares over Boolean vectors and prime fields constructed earlier are generalized to the case of Abelian groups. Some criteria for realizability of this construction are presented. Some classification results are also given. __________ Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 12, No. 3, pp. 65–71, 2006.     

The dynamics of the weakly perturbed motion of a liquid-filled gyroscope and the control problem

The Cauchy problem for the motion of a dynamically symmetrical rigid body with a cavity, filled with an ideal liquid, which is perturbed from uniform rotation, is considered in a linear formulation. The problem of the simultanious solution of the equations of hydrodynamics and the mechanics of a rigid body is reduced to the solution of an eigenvalue problem which depends solely on the geometry of the cavity and the subsequent integration of a system of differential equations.     

Nonconservation of the quantum number K and phase transitions in rapidly rotating nuclei

Three different effects observed in experiments with rotating nuclei—backbending, noncollective quadrupole transitions between different levels of the same band, and transitions that occur, in rapidly rotating nuclei, from large-K isomeric states immediately to the levels of a rotational band despite their strong forbiddenness in K—are explained in terms of nonconservation of the quantum number K in such nuclei.     

Chirp Ionosonde and Its Application in the Ionospheric Research

We present a review of materials related to a chirp ionosonde and its application in the ionospheric research. The principle of operation of an ionosonde radiating a continuous signal with linear frequency modulation is described. The chirp-ionosonde resolution and gain in the signal-to-noise ratio are estimated. Examples of applying a chirp ionosonde to problems of ionospheric HF-wave propagation are considered. Prospects for ionospheric research on the basis of a network of oblique chirp-sounding paths are discussed.