Observation of Large Differences in the Diffraction of Normal- and Para-H2 from LiF(001)

Theoretical Chemistr

Spontaneous magnetization of aluminum nanowires deposited on the NaCl(100) surface

We investigate electronic structures of Al quantum wires, both unsupported and supported on the (100) NaCl surface, using the density-functional theory. We confirm that unsupported nanowires, constrained to be linear, show magnetization when elongated beyond the equilibrium length. Allowing ions to relax, the wires deform to zig-zag structures with lower magnetization but no dimerization occurs. When an Al wire is deposited on the NaCl surface, a zig-zag geometry emerges again. The magnetization changes moderately from that for the corresponding unsupported wire. We analyse the findings using electron band structures and simple model wires.Comment: submitted to PHys. Rev.

Catastrophe theory and resonance line shapes in atom-surface scattering

The measured high-resolution energy profile of a selective adsorption resonance in the scattering of He atoms from NaCl(001) is found to exhibit a mixed-extrema structure reminiscent of a Fano-type function. An analysis of the topological properties of the resonance line shape as a function of the surface temperature reveals a behavior which is isomorphic to the simplest elementary catastrophe, the fold catastrophe. As the crystal temperature approaches the surface Debye temperature ΘD of NaCl the resonance profile undergoes a transition in its topology according to the behavior of the fold catastrophe. The analysis is sufficiently general in order to be extended to any resonant scattering event displaying Fano-type profiles. ©1999 The American Physical Society.This work has been supported in part by DGICYT ~Spain! under Contract Nos. PB96-0651-C03-01 and PB95-0071.Peer Reviewe

Distance Learning in the Humanitarian Field amid the Coronavirus Pandemic: Risks of Creating Barriers and Innovative Benefits

The goal of the research is to study the risks and innovative benefits of distance learning. The main research method is an anonymous survey of academic staff (university teachers) and students (future philologists, foreign language teachers), based on the need to clarify the situation associated with the use of distance learning technologies in the conditions of the quarantine. The following data have been obtained in the course of the study: the most significant opportunities for distance learning, the level of satisfaction with distance learning technologies, the compliance with the previously drawn up training schedule in the distance learning conditions, the satisfaction with the promptness of informing about the training schedule, the use of distance learning technologies to provide feedback, the factors that affect the quality of the implementation of distance learning technologies, the teachers' positive experience of using distance learning technologies, the use of distance learning technologies when providing students with lecture materials, as well as the use of information resources of the institution by the students. The results of the study have revealed that both students and teachers are aware of the need to work in a distance learning environment, but the coronavirus pandemic has created new risks for the higher education system, which require an innovative approach to overcoming barriers in the distance learning system. The results of the article can be used in the organization of distance learning at a humanitarian university

Optics in computers servers and data centers

Based on well-known laws of physics, a lower bound on the energy-per-bit required for transmitting information using a photonic channel is established. The analysis includes the energy required to convert information from the electronic to the photonic domain and back. We investigate links that employ a directly modulated laser as well as links that employ an external modulator. It is shown that the power dissipation of the channel also imposes a bound on the maximum bandwidth density for a photonic link. Keeping this in mind, opportunities for optics in computing systems are discussed, especially from a systems perspective

Симптомы сезонных аффективных расстройств (САД) и снижение качества жизни (КЖ) как предикторы снижения функциональных резервов организма к африканских студентов-медиков во время учёбы и жизни в Москве

We showed that African students during their studies and life in Moscow during the winter (December-January) in relation to the summer period (June) significantly reduced the functional reserves of the body. The total index of symptoms of seasonal affective disorders (SAD) in winter was 9 ± 0.4 units, and in the summer period the same indicator was 4±0.4 unit. (P≤0.05). Such integrative indicators of the Quality of Life (QoL) as Mental (MH) and Physical Health (PH) were also significantly lower among African medical students in the winter period.The total index of the Heart Rhythm Variability (HRV) for R.M. Bayevsky (1-4), correlated with the level of functional reserves of the body (IARS - Regulatory System Activity Index) was significantly higher in the surveyed African students in the winter period compared to the same indicator in the surveyed in the summer period - 6±0.4 and 2 ± 0.1 respectively (P≤ 0.05).The data obtained show that the received Quality of Life and the degree of expression of seasonal affective disorders can serve as predictive predictors in assessing the level of functional reserves of the body of African students in changed climatic and geographical conditions.Нами было показано, что у Африканских студентов во время учёбы и жизни в Москве в зимний период (декабрь-январь) по отношению к летнему периоду (июнь) существенно снизились функциональные резервы организма. Суммарный показатель выраженности симптомов сезонных аффективных расстройств (САР) в зимний период составил 9±0.4 ед., а в летний период аналогичный показатель был равен 4±0.4 ед. (Р≤0.05).Такие интегративные показатели Качества Жизни (КЖ) как Ментальное (МЗ) и Физическое Здоровье (ФЗ) были также существенно ниже у Африканских студентов- медиков в зимний период времени.Суммарный показатель Вариабельности Сердечного Ритма (ВСР) по Р.М. Баевскому, соотносящийся с уровнем функциональных резервов организма (ПАРС - Показатель Активности Регуляторных Систем) был существенно выше у обследуемых Африканских студентов в зимний период времени по отношению к аналогичному показателю у обследуемых в летний период времени - 6±0.4 и 2±0.1 соответственно (Р≤0.05).Полученные данные свидетельствуют о том, что полученные показатели Качества Жизни и степень выраженности Сезонных аффективных расстройств могут служить прогностическими предикторами при оценке уровня функциональных резервов организма Африканских студентов изменённых климато-географических условиях