Experimental demonstration of stimulated polarization wave in a chain of nuclear spins

A stimulated wave of polarization, which implements a simple mechanism of quantum amplification, is experimentally demonstrated in a chain of four J-coupled nuclear spins, irradiated by a weak radio-frequency transverse field. The "quantum domino" dynamics, a wave of flipped spins triggered by a flip of the first spin, has been observed in fully $^{13}$C-labeled sodium butyrate.Comment: 8 pages including 3 figure

Projective measurement in nuclear magnetic resonance

It is demonstrated that nuclear magnetic resonance experiments using pseudopure spin states can give possible outcomes of projective quantum measurement and probabilities of such outcomes. The physical system is a cluster of six dipolar-coupled nuclear spins of benzene in a liquid-crystalline matrix. For this system with the maximum total spin S=3, the results of measuring $S_X$ are presented for the cases when the state of the system is one of the eigenstates of $S_Z$.Comment: 9 pages incluing 3 figure

Professionalization of social groups: research traditions and ongoing features.

The article is aimed at defining the extent of the applicability of traditional approaches to the exploration of professionalization of social groups. It is accomplished by the separation of certain relevant features of the “classical” model of professionalization which is used in foreign sociology of professions. Matching these features with specific traits of the modern stage of professions’ development allowed us to make a conclusion about the necessity of reconsidering some features of the said “classical” model, for instance, in the context of the increase of educational practices’ significance as an aspect of the professionalization process.Цель статьи — определить степень применимости в современных условиях традиционных подходов к изучению процесса профессионализации социальных групп. Это достигается посредством выделения некоторых релевантных черт «классической» модели профессионализации, используемой в зарубежной социологии профессий. Соотнесение данных черт и специфических моментов современного этапа развития профессий позволило сделать вывод о необходимости пересмотра ряда характеристик «классической» моде-ли, например, в контексте возрастания значения образовательных практик как аспекта процесса профессионализации

Selective excitation of homogeneous spectral lines

It is possible, for homogeneously broadened lines, to excite selectively the response signals, which are orders of magnitude narrower than the original lines. The new type of echo, which allows detecting such signals, and the formalism, useful for understanding the phenomenon, as well as the experimental examples from NMR spectroscopy are presented.Comment: 19 pages, 8 figure