TY  - JOUR
A1  - Guliakova, A. A.
A1  - Gorokhovatsky, Yu. A.
A1  - Galikhanov, M. F.
A1  - Frübing, Peter
T1  - Thermoactivational spectroscopy of the high impact polystyrene based composite films
T1  - Термоактивационная спектроскопия композитных полимерных пленок на основе ударопрочного полистирола
JF  - St. Petersburg Polytechnic University Journal : Physics and Mathematics
N2  - The relaxation processes in the high impact polystyrene (HIPS) films filled with 2, 4, 6 vol.% of titanium dioxide (TiO2) of the rutile modification have been studied using the thermally stimulated depolarization current (TSDC) technique. Three relaxation processes were observed in the composite HIPS films. The first one (a-relaxation peak) appeared at about 93 degrees C and represented the glass transition. The second peak p was a high-temperature part of the first one and overlapped it. The p peak was caused by the release and subsequent motion of excess charges deposited during the electret preparation or the polarization process. The third peak appeared at about 150 degrees C and occurred only in the spectra of the composite films. The overlapping peaks were separated by the thermal cleaning technique. The subsequent application of the numerical methods (the Tikhonov regularization technique) allowed to determine the activation energy of the second process and to compare the obtained value with the corresponding data on the dielectric relaxation.
N2  - С помощью метода токов термостимулированной деполяризации (ТСД) исследованы релаксационные процессы в пленках ударопрочного полистирола (УПС) без наполнителя и с различным содержанием диоксида титана TiO2 (2, 4, 6 об.%). На кривых тока ТСД, полученных для композитных пленок, обнаружено три пика. Первый (α-релаксация) возникает при температуре около 93 °C и соответствует переходу вещества из стеклообразного состояния в высокоэластическое. Второй (ρ-пик) появляется как высокотемпературное плечо α-пика и соответствует процессу высвобождения и движения избыточных носителей заряда. Наличие третьего пика при температуре около 150 ºС характерно только для композитных пленок УПС. Разделение перекрывающихся α- и ρ-пиков проведено методом частичной термоочистки. Последующее применение регуляризующих алгоритмов Тихонова позволило определить энергию активации второго процесcа и сравнить полученное значение с результатом, полученным методом диэлектрической спектроскопии.
KW  - thermoactivational spectroscopy
KW  - high impact polystyrene
KW  - titanium dioxide
Y1  - 2019
U6  - https://doi.org/10.18721/JPM.12401
SN  - 2405-7223
SN  - 2618-8686
SN  - 2304-9782
VL  - 12
IS  - 4
SP  - 9
EP  - 16
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Bogdanova, Oksana Yu
A1  - Miklashevsky, Alex A.
A1  - Bogdanova, Elena L.
A1  - Soldatenkova, O. B.
T1  - Academic Achievement in Math and Foreign Language: Individual Characteristics and Gender Stereotypes
JF  - Sibirskiy psikholoicheskiy zurnal - Siberian of Journal psychology
N2  - The study aims to investigate the contribution of individual characteristics and gender stereotypes of secondary school pupils in academic achievement in math and foreign language. A sample of pupils reported in 6th and 7th grades (three waves) their self-perceived ability and motivation for math and foreign language learning, math and foreign language gender stereotypes, implicit theories of intelligence; academic achievement (grades) in math in foreign language is also included in the analysis. Regression analysis and Mann Whitney U Test demonstrated that self-perceived ability in math and incremental theory of intelligence are significant predictors for academic achievement in maths. Boys are characterised by higher level of self-perceived abilities and motivation for learning math. However, academic achievement of girls in maths and foreign languages are higher as compared to boys. Pupils learning two foreign languages demonstrate higher level of self-perceived abilities for motivation and learning math and less expressed gender stereotypes about success in learning math and foreign languages. Study findings can be used for designing educational programmes for mathematics and foreign languages, professional development and finding solutions for individualized approach in school education.
KW  - self-perceived ability
KW  - motivation
KW  - gender stereotype
KW  - implicit theory of intelligence
KW  - mathematics
KW  - foreign language
KW  - academic achievement
Y1  - 2019
U6  - https://doi.org/10.17223/17267080/73/11
SN  - 1726-7080
SN  - 2411-0809
IS  - 73
SP  - 176
EP  - 196
PB  - Tomsk state univ
CY  - Tomsk
ER  -