Even harmonic generation in isotropic media of dissociating homonuclear molecules

Isotropic gases irradiated by long pulses of intense IR light can generate very high harmonics of the incident field. It is generally accepted that, due to the symmetry of the generating medium, be it an atomic or an isotropic molecular gas, only odd harmonics of the driving field can be produced. Here we show how the interplay of electronic and nuclear dynamics can lead to a marked breakdown of this standard picture: a substantial part of the harmonic spectrum can consist of even rather than odd harmonics. We demonstrate the effect using ab-initio solutions of the time-dependent Schr\"odinger equation for $H$$_2$$^+$ and its isotopes in full dimensionality. By means of a simple analytical model, we identify its physical origin, which is the appearance of a permanent dipole moment in dissociating homonuclear molecules, caused by light-induced localization of the electric charge during dissociation. The effect arises for sufficiently long laser pulses and the region of the spectrum where even harmonics are produced is controlled by pulse duration. Our results (i) show how the interplay of femtosecond nuclear and attosecond electronic dynamics, which affects the charge flow inside the dissociating molecule, is reflected in the nonlinear response, and (ii) force one to augment standard selection rules found in nonlinear optics textbooks by considering light-induced modifications of the medium during the generation process.Comment: 7 pages, 6 figure

Lamellar structure and nanomechanical properties of quasicrystalline Al-Cu-Fe alloys

The kinetics of structural phase transformations in quasicrystal-forming Al-Cu-Fe alloys with compositions in the region of stability of the icosahedral (i) phase has been investigated. It has been shown that, depending on the development of metastable transformations i → pentagonal phases P1 and P2, a homogeneous lamellar structure (i + P1 + P2) or a polygrain i-phase is formed in the alloys. The P-h diagrams obtained upon nanoindentation, atomic force microscopy, and scanning electron microscopy of indentations have demonstrated signs of elasto-plastic deformation of the alloys with lamellar and polygrain icosahedral structures. It has been found that, in contrast to the polygrain icosahedral alloys with a normal size effect of nanoindentation, the alloys with a lamellar structure are characterized by a nonmonotonic dependence of the hardness (H) on the maximum load (P max) and exhibit the effect of strain hardening in the range of loads 50 mN ≤ P max < 500 mN. The strain hardening is considered as the result of resistance exerted by boundaries of the lamellar structure to the development of plastic deformation. © 2013 Pleiades Publishing, Ltd

Evaluative Potential of Lexemes — Representatives of Concept TRUE in Russian

The study of the evaluative potential of the concept TRUTH in the Russian language picture of the world has been carried out. The results of the analysis of the use of the word true in the role of a qualitative adjective with evaluative semantics and the word truly in the role of a qualitative adverb with the semantics of the degree of manifestation of a property, feature or action / state are presented based on the materials of the Russian National Corpus and the authors’ own Internet monitoring in the Russian-speaking segment of the Internet. It is shown that in the total semantic content of the concept TRUTH, two semantic layers of its conceptual content in the modern Russian are realized: correspondence to reality; compliance with the norm in the world of people, the highest ideal. The following varieties of uses of the qualitative adjective true and the qualitative adverb truly as a secondary assessment based on the general meaning of “corresponding to the ideal in the world of norms and values of the speaker” were found: the meaning is “ideal, exemplary, perfect”; the meaning is “full, reached / brought to the maximum degree of manifestation of the entity named by the defined word” and the meaning of a strong degree of manifestation of something. It is concluded that the words true and truly embody the subjective moral and value ideas of native speakers about how it should be in the world of human relations, and not about “how it really is”

The content of the studies on discipline «Physical culture» in the context of preserving the University studentshealth

The article provides data on the health of students. The author grounds the necessity of the change of the training discipline «Physical culture» contentВ статье приведены данные состояния здоровья студентов. Обоснована необходимость изменения содержания обучения по дисциплине «Физическая культура

Morphological Substantiation of Clinical Efficacy of Platelet Rich Plasma in the Treatment of Androgenetic Alopecia

The aim of the study was morphological substantiation of clinical efficacy of platelet rich plasma (PRP) in the treatment of patients with androgenetic alopecia (AGA). Materials and Methods: The study included 25 men aged from 20 to 43 years. AGA degree II-IV on the Hamilton-Norwood scale was diagnosed in 23 (92%) patients and degree I in 2 patients. All patients received intradermal injections of PRP. The course of treatment consisted of 4 procedures with an interval of 4 weeks between each procedure. The clinical efficacy of the therapy was evaluated by the dynamics of morphometric indicators of hair growth. The morphological analysis included an assessment of indicators in horizontal sections and was carried out at 4 levels: at the level of subcutaneous adipose tissue, sweat glands, sebaceous glands, and mouths of hair follicle (HF). Sections were stained with H&E. Histological examination was performed before and after treatment. Against the background of treatment with PRP, hair density increased by 12% (P=0.000), average hair diameter by 12% (P=0.002), and the share of vellus and telogen hair decreased by 17% (P=0.002) and 16% (P=0.028), respectively. At the same time, the amount of anagen hair in relation to telogen hair increased by 18% (P=0.016). Histologically, the increase in hair density was accompanied by a significant increase in the number of HF at the mouth level (∆+96%, P=0.004) and at the level of sweat glands (∆+54%, P=0.037), as well as a tendency for their number to increase at the level of the sebaceous glands. These increases were combined with a significant decrease in the proportion of telogen hair (∆-43%, P=0.023) and vellus hair (∆-29%, P=0.037). Conclusion: The positive clinical effect of PRP therapy is due to significant morphofunctional changes in hair follicles

КОМПЛЕКСНАЯ МОДЕЛЬ СОВЕРШЕНСТВОВАНИЯ ВЫСШЕГО УЧЕБНОГО ЗАВЕДЕНИЯ

The article explores issues related to application of competitive techniques and diagnostic self-assessments along with traditional methods of quality assessment activities inhigher institutions.The author shows the main difference of self-assessment from measuring the quality of activity; the method of self-assessment is applied in licence, accreditation and self-investigation. The publication focuses on application of competitive self-assessment by national universities. The author suggests applying of complex integrated model, demonstrates interaction between different methods of activity assessment and makes prospective students, partners and society sure that higher institution provides high-rank and competitive education.В статье рассматриваются вопросы, связанные с применением высшими учебными заведениями методик конкурсной и диагностической самооценок наряду с традиционными методами оценки качества деятельности. Приводятся основные отличия метода самооценки от процесса измерения показателей качества деятельности, который используется при лицензировании, аккредитации и самообследовании. Особое внимание уделяется анализу применения конкурсной самооценки вузами нашей страны. Предложенная автором комплексная модель совершенствованияиллюстрирует взаимосвязь между различными методами оценки деятельности, позволяядать абитуриентам, партнерам, обществу уверенность в том, что высшее учебное заведение оказывает высококачественные и конкурентоспособные образовательные услуги