Laser-induced persistent photovoltage on the surface of a ternary topological insulator at room temperature

Using time- and angle-resolved photoemission, we investigate the ultrafast response of excited electrons in the ternary topological insulator (Bi$_{1 x}$Sb$_{x}$)$_2$Te$_3$ to fs-infrared pulses. We demonstrate that at the critical concentration $x$=0.55, where the system becomes bulk insulating, a surface voltage can be driven at room temperature through the topological surface state solely by optical means. We further show that such a photovoltage persists over a time scale that exceeds $\sim$6 $\mu$s, i.e, much longer than the characteristic relaxation times of bulk states. We attribute the origin of the photovoltage to a laser-induced band-bending effect which emerges near the surface region on ultrafast time scales. The photovoltage is also accompanied by a remarkable increase in the relaxation times of excited states as compared to undoped topological insulators. Our findings are relevant in the context of applications of topological surface states in future optical devices.Comment: 5 pages, 4 figure

Citation as a stimulus to boost students’ communication skills at the English lessons

© Canadian Center of Science and Education. The study contemplates significance of using citation at the English lessons by exposing its advantages. Quotations represent the enormous linguistic variety, which discloses the modern language that unambiguously assists students to develop skills of oral speech. Special attention is paid to the experimentconducted at the series of lessons in order to enhance students’ linguistic interest, incentive and aimed at the development and improvement of communicative competence

Approach to Evaluating Characteristics of Multichannel Loss System with FCFD Preempted Priority Discipline

In the paper we consider a multichannel loss preemptive priority system with a Poisson input and general service time distribution depending on the priority of job. Jobs of the same priority are preempted according with First Come First Displaced (FCFD) protocol. Approximate formulas are obtained for the loss probability of a prescribed priority job and some other characteristics of the system. It particular cases, the obtained formulas are exact.Comment: 6 pages, no figures. arXiv admin note: text overlap with arXiv:2206.0926

Implementing environmental culture in the language learning laboratory

© Canadian Center of Science and Education. The article deals with the description of the experimental work aimed at testing the effectiveness of the pedagogical conditions used in the environmental education of senior pupils by means of a foreign language. It is worth mentioning that during the experiment under the detection of the formation of the environmental education of senior pupils were identified the indicators by which we understand the environmental characteristics of the personality traits. The results were derived from the methods used in the process of the experiment, such as: conversation, testing, verification of empirical skills, analysis and synthesis. On the whole the difference in the results of the experimental groups significantly allows us to state the effectiveness of pedagogical conditions of the environmental education of senior pupils by means of a foreign language

The Development of Sociocultural Competence with the Help of Computer Technology

© 2016, Springer Science+Business Media Dordrecht.The article deals with the description of the process of development sociocultural knowledge and competences using computer technologies. On the whole the development of modern computer technologies allows teachers to broaden trainees’ sociocultural outlook and trace their progress online. Observation of modern computer technologies and estimation of their ability to help teachers was the main question of this article. During the experiment the authors implemented the following research methods: method of observation, sociometric method, test, survey. The objectives of the experimental work were: (1) Identification of the level of development of socio-cultural competence of students; (2) Detection of the most optimal features of comprehensive integration and implementation of pedagogical conditions for development of students’ socio-cultural competence; (3) Verification of the effectiveness of pedagogical conditions for development of socio-cultural competence of students in the socio-cultural projects. Cognitive activity of students under which the authors understand the process of creative knowledge of foreign culture is increasing with the use of computer technologies. Thus, this process changes the general educational purposes of humanities. In this article the authors enumerate main skills and abilities required from the teacher who use computer technology in sociocultural environment. On the whole the level of sociocultural competence can be advanced with the help of computer technologies as it provides wide opportunities for students to take part in joint-work international projects

Linguistic peculiarities of the modern political discourse of russia and the usa

The article is dedicated to identifying the significant role of language as influential instrument of political ideology by exploring the most iterative linguistic devices used in the contemporary political discourse of two countries, namely Russia and the United States of America, thereby outlining similar and various peculiarities inherent to both countries. Recently political issues have been brought forefront. Therefore, the modern political discourse is of our main interest, namely from linguistic point of view, investigation of lexical stylistic devices used by politicians aimed at achieving specific goals, so far as this aspect has not been comprehensively analyzed yet. The methodology of this research has applied general principles of qualitative research, and it has been based on the discourse analysis of the authentic source materials published in the New York Times, American Rhetoric and RIA novosti. The research is of great value for further scientific investigations in the fields of the political linguistics. The study delineates further perspectives of the comparative investigations in the English and Russian languages and in the field of the different aspects of the political discourse and the political communication

The Development of Sociocultural Competence with the Help of Computer Technology

© 2016 Springer Science+Business Media DordrechtThe article deals with the description of the process of development sociocultural knowledge and competences using computer technologies. On the whole the development of modern computer technologies allows teachers to broaden trainees’ sociocultural outlook and trace their progress online. Observation of modern computer technologies and estimation of their ability to help teachers was the main question of this article. During the experiment the authors implemented the following research methods: method of observation, sociometric method, test, survey. The objectives of the experimental work were: (1) Identification of the level of development of socio-cultural competence of students; (2) Detection of the most optimal features of comprehensive integration and implementation of pedagogical conditions for development of students’ socio-cultural competence; (3) Verification of the effectiveness of pedagogical conditions for development of socio-cultural competence of students in the socio-cultural projects. Cognitive activity of students under which the authors understand the process of creative knowledge of foreign culture is increasing with the use of computer technologies. Thus, this process changes the general educational purposes of humanities. In this article the authors enumerate main skills and abilities required from the teacher who use computer technology in sociocultural environment. On the whole the level of sociocultural competence can be advanced with the help of computer technologies as it provides wide opportunities for students to take part in joint-work international projects