183 research outputs found
ΠΡΡΠΎΠΊΠΈ Π΄Π΅Π³ΡΠΌΠ°Π½ΠΈΠ·Π°ΡΠΈΠΈ Π½Π°ΡΡΠ½ΠΎΠ³ΠΎ Π·Π½Π°Π½ΠΈΡ
ΠΠΎΡΡΠ°Π²Π»Π΅Π½Π° ΠΏΡΠΎΠ±Π»Π΅ΠΌΠ° Π΄Π΅Π³ΡΠΌΠ°Π½ΠΈΠ·Π°ΡΠΈΠΈ Π½Π°ΡΡΠ½ΠΎΠ³ΠΎ Π·Π½Π°Π½ΠΈΡ. ΠΠΎΠΊΠ°Π·Π°Π½Ρ ΠΏΡΠΎΡΠΈΠ²ΠΎΡΠ΅ΡΠΈΡ Π² ΠΈΠ½ΡΠ΅ΡΠΏΡΠ΅ΡΠ°ΡΠΈΠΈ ΡΠ²Π»Π΅Π½ΠΈΡ Π΄Π΅Π³ΡΠΌΠ°Π½ΠΈΠ·Π°ΡΠΈΠΈ Π² ΡΡΠ΅ΡΠ΅ Π³ΡΠΌΠ°Π½ΠΈΡΠ°ΡΠ½ΠΎΠ³ΠΎ ΠΈ Π΅ΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠ½Π°ΡΡΠ½ΠΎΠ³ΠΎ Π·Π½Π°Π½ΠΈΡ. ΠΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Ρ ΡΡΠ»ΠΎΠ²ΠΈΡ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π΅Π²ΡΠΎΠΏΠ΅ΠΉΡΠΊΠΎΠΉ Π½Π°ΡΠΊΠΈ Π² ΡΠΏΠΎΡ
Ρ ΠΠ½ΡΠΈΡΠ½ΠΎΡΡΠΈ ΠΈ ΠΊΡΠΈΡΠ΅ΡΠΈΠΈ Π½Π°ΡΡΠ½ΠΎΠ³ΠΎ Π·Π½Π°Π½ΠΈΡ, ΡΡΠΎΡΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΡΠ΅ Π² XVII Π². Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ ΠΈΡΡΠΎΠΊΠΈ Π΄Π΅Π³ΡΠΌΠ°Π½ΠΈΠ·Π°ΡΠΈΠΈ Π·Π°Π»ΠΎΠΆΠ΅Π½Ρ Π² ΡΠ°ΠΌΠΎΠΉ ΡΠΏΠ΅ΡΠΈΡΠΈΠΊΠ΅ Π½Π°ΡΡΠ½ΠΎΠ³ΠΎ Π·Π½Π°Π½ΠΈΡ. Π‘Π΄Π΅Π»Π°Π½ Π²ΡΠ²ΠΎΠ΄ ΠΎ ΡΠΎΠΌ, ΡΡΠΎ ΠΎΡΡΡΠ΅ΡΡΠ²Π»ΡΠ΅ΠΌΠ°Ρ Π² ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΡΡΠΈ Π³ΡΠΌΠ°Π½ΠΈΠ·Π°ΡΠΈΡ Π½Π°ΡΠΊΠΈ Π΄ΠΎΠ»ΠΆΠ½Π° ΠΏΡΠΎΡ
ΠΎΠ΄ΠΈΡΡ Π² ΠΎΠ±Π»Π°ΡΡΠΈ ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ Π½Π°Π²ΡΠΊΠΎΠ² ΠΏΡΠΎΠ±Π»Π΅ΠΌΠ½ΠΎΠ³ΠΎ ΠΌΡΡΠ»Π΅Π½ΠΈΡ
Grain coarsening in two-dimensional phase-field models with an orientation field
In the literature, contradictory results have been published regarding the
form of the limiting (long-time) grain size distribution (LGSD) that
characterizes the late stage grain coarsening in two-dimensional and
quasi-two-dimensional polycrystalline systems. While experiments and the
phase-field crystal (PFC) model (a simple dynamical density functional theory)
indicate a lognormal distribution, other works including theoretical studies
based on conventional phase-field simulations that rely on coarse grained
fields, like the multi-phase-field (MPF) and orientation field (OF) models,
yield significantly different distributions. In a recent work, we have shown
that the coarse grained phase-field models (whether MPF or OF) yield very
similar limiting size distributions that seem to differ from the theoretical
predictions. Herein, we revisit this problem, and demonstrate in the case of OF
models [by R. Kobayashi et al., Physica D 140, 141 (2000) and H. Henry et al.
Phys. Rev. B 86, 054117 (2012)] that an insufficient resolution of the small
angle grain boundaries leads to a lognormal distribution close to those seen in
the experiments and the molecular scale PFC simulations. Our work indicates,
furthermore, that the LGSD is critically sensitive to the details of the
evaluation process, and raises the possibility that the differences among the
LGSD results from different sources may originate from differences in the
detection of small angle grain boundaries
Feedback Cooling of a Single Neutral Atom
We demonstrate feedback cooling of the motion of a single rubidium atom
trapped in a high-finesse optical resonator to a temperature of about 160 \mu
K. Time-dependent transmission and intensity-correlation measurements prove the
reduction of the atomic position uncertainty. The feedback increases the 1/e
storage time into the one second regime, 30 times longer than without feedback.
Feedback cooling therefore rivals state-of-the-art laser cooling, but with the
advantages that it requires less optical access and exhibits less optical
pumping.Comment: 5 pages, 4 figure
ΠΠΏΠΏΠ°ΡΠ°ΡΠ½ΠΎ-ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ½ΡΠΉ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡ Π΄Π»Ρ ΠΎΡΠ΅Π½ΠΊΠΈ ΠΏΡΠΈΡ ΠΎΡΠΌΠΎΡΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Π½Π° Π½Π°Π½ΠΎΡΠ΅Π½ΡΠΎΡΠ°Ρ
ΠΠ°Π½Π½Π°Ρ Π΄ΠΈΡΡΠ΅ΡΡΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ°Π±ΠΎΡΠ° ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠΈΡ
ΠΎΡΠΌΠΎΡΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ Π½Π° Π°ΠΏΠΏΠ°ΡΠ°ΡΠ½ΠΎ-ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ½ΠΎΠΌ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ΅ Ρ ΠΏΠΎΠΌΠΎΡΡΡ Π½Π°Π½ΠΎΡΠ΅Π½ΡΠΎΡΠΎΠ². ΠΡΠ» ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ Π°Π½Π°Π»ΠΈΠ· ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΠΌΠ΅ΡΠΎΠ΄ΠΎΠ² ΠΈ ΠΏΡΠΈΠ±ΠΎΡΠΎΠ² ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ ΡΠ»Π΅ΠΊΡΡΠΎΡΠΈΠ·ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ², ΡΠ²ΡΠ·Π°Π½Π½ΡΡ
Ρ ΠΏΡΠΈΡ
ΠΎΡΠΌΠΎΡΠΈΠΎΠ½Π°Π»ΡΠ½ΡΠΌ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ΠΌ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ°. Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° ΠΏΡΠ΅Π΄Π²Π°ΡΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ ΠΏΡΠΈΡ
ΠΎΡΠΌΠΎΡΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Π½Π° Π°ΠΏΠΏΠ°ΡΠ°ΡΠ½ΠΎ-ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ½ΠΎΠΌ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ΅. ΠΡΠΎΠ²Π΅Π΄Π΅Π½Ρ ΠΏΡΠ΅Π΄Π²Π°ΡΠΈΡΠ΅Π»ΡΠ½ΡΠ΅ ΠΌΠ΅Π΄ΠΈΡΠΈΠ½ΡΠΊΠΈΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠΈΡ
ΠΎΡΠΌΠΎΡΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ. ΠΠ° ΠΈΡ
ΠΎΡΠ½ΠΎΠ²Π΅ ΠΏΠΎΠΊΠ°Π·Π°Π½Π° Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΡ Π·Π½Π°ΡΠ΅Π½ΠΈΠΉ ΠΌΠΈΠΊΡΠΎΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΠΎΠ² ΠΏΠΎ ΡΠ°Π·Π½ΡΠΌ ΡΠΈΠΏΠ°ΠΌ Π²ΠΎΠΏΡΠΎΡΠΎΠ², Π·Π°ΡΠ΅Π³ΠΈΡΡΡΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
Π² ΡΠ΅Π°Π»ΡΠ½ΠΎΠΌ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π½ΡΠΌ ΠΠΠ, Π½Π° ΡΠ΅Π°ΠΊΡΠΈΡ Π³Π½Π΅Π²Π°, ΡΡΡΠ°Ρ
Π°, Π³ΡΡΡΡΠΈ ΠΈ Π½Π΅ΠΉΡΡΠ°Π»ΡΠ½ΡΡ
Π²ΠΎΠΏΡΠΎΡΠΎΠ².. ΠΠ°Π½Π½ΠΎΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΡΠΈΠΌΠ΅Π½ΠΈΠΌΠΎ Π΄Π»Ρ ΠΎΡΠ΅Π½ΠΊΠΈ Π΄ΠΎΡΡΠΎΠ²Π΅ΡΠ½ΠΎΡΡΠΈ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΈ, ΡΠΎΠΎΠ±ΡΠ°Π΅ΠΌΠΎΠΉ ΠΈΡΠΏΡΡΡΠ΅ΠΌΡΠΌ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠΎΠΌ,This dissertational work is devoted to the study of the psychoemotional state on the hardware-software complex with the help of nanosensors. An analysis was made of modern methods and devices for recording the electrophysiological parameters associated with the psychoemotional state of a person. A technique for preliminary studies of the psychoemotional state of a person on the hardware and software complex has been developed. Preliminary medical studies of the psychoemotional state were carried out. On their basis, the dependence of the values of micro-potentials on different types of questions registered in real time by the AIC on the reaction of anger, fear, sadness and neutral questions is shown. This study is applicable for assessing the reliability of information reported by a test
ΠΠ»ΠΈΡΠ½ΠΈΠ΅ ΡΠΎΠ»ΡΠΈΠ½Ρ ΠΈ Π²Π·Π°ΠΈΠΌΠ½ΠΎΠ³ΠΎ ΡΠ°ΡΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΡ ΡΠ»ΠΎΠ΅Π² Π² ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΈ ΠΆΠ΅Π»Π΅Π·ΠΎ-ΠΏΠΎΠ»ΠΈΡΡΠΈΠ»Π΅Π½ Π½Π° ΡΠ½Π΅ΡΠ³Π΅ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ Π±ΡΡΡΡΡΡ Π½Π΅ΠΉΡΡΠΎΠ½ΠΎΠ²
Π Π°ΡΡΠ΅Ρ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΠ»ΡΡ Π΄Π»Ρ Π΄Π²ΡΡ
ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΉ: ΠΆΠ΅Π»Π΅Π·ΠΎ-ΠΏΠΎΠ»ΠΈΡΡΠΈΠ»Π΅Π½, ΠΏΠΎΠ»ΠΈΡΡΠΈΠ»Π΅Π½-ΠΆΠ΅Π»Π΅Π·ΠΎ. Π£ΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ ΠΏΠ΅ΡΠ΅Π½ΠΎΡΠ° Π½Π΅ΠΉΡΡΠΎΠ½ΠΎΠ² ΡΠ΅ΡΠ°Π»ΠΎΡΡ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠΎΠ½ΡΠ΅-ΠΠ°ΡΠ»ΠΎ Π² ΡΡΠ°Π½ΡΠΏΠΎΡΡΠ½ΠΎΠΌ ΠΏΡΠΈΠ±Π»ΠΈΠΆΠ΅Π½ΠΈΠΈ. ΠΠΎΠ»ΡΡΠ΅Π½Π½ΡΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΡΡΡ ΠΎ Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠΌ Π²Π»ΠΈΡΠ½ΠΈΠΈ ΡΠ»ΠΎΡ Π»Π΅Π³ΠΊΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° Π½Π° Π²Π΅Π»ΠΈΡΠΈΠ½Ρ ΠΏΠΎΡΠΎΠΊΠ° ΠΈ ΡΠ½Π΅ΡΠ³Π΅ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ ΠΏΡΠΎΡΠ΅Π΄ΡΠΈΡ
Π½Π΅ΠΉΡΡΠΎΠ½ΠΎΠ², ΡΡΠΎ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ ΠΎΡΡΡΠ΅ΡΡΠ²ΠΈΡΡ Π²ΡΠ±ΠΎΡ ΡΠ½Π΅ΡΠ³Π΅ΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π° ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ ΠΏΡΠΎΡΠ΅Π΄ΡΠ΅Π³ΠΎ ΠΏΠΎΡΠΎΠΊΠ° Π΄Π»Ρ ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΡ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠΉ ΠΈΠ·Π±ΠΈΡΠ°ΡΠ΅Π»ΡΠ½ΠΎΠΉ ΡΡΠ²ΡΡΠ²ΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΠΈ ΠΊ ΡΠ»ΠΎΡ Π»Π΅Π³ΠΊΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π°
ΠΠ°ΡΠ΅ΡΡΠ°Π»ΠΈ ΡΡΡΠ΄Π΅Π½ΡΡΡΠΊΠΎΡ Π½Π°ΡΠΊΠΎΠ²ΠΎΡ ΠΊΠΎΠ½ΡΠ΅ΡΠ΅Π½ΡΡΡ (ΠΠ½ΡΠΏΡΠΎΠΏΠ΅ΡΡΠΎΠ²ΡΡΠΊ, 21-23 Π±Π΅ΡΠ΅Π·Π½Ρ 2012 ΡΠΎΠΊΡ)
ΠΠΈΠΊΠ»Π°Π΄Π΅Π½ΠΎ ΡΠ΅Π·ΠΈ Π΄ΠΎΠΏΠΎΠ²ΡΠ΄Π΅ΠΉ ΡΡΠ°ΡΠ½ΠΈΠΊΡΠ² ΠΌΡΠΆΠ½Π°ΡΠΎΠ΄Π½ΠΎΡ Π½Π°ΡΠΊΠΎΠ²ΠΎ-ΠΏΡΠ°ΠΊΡΠΈΡΠ½ΠΎΡ ΠΊΠΎΠ½ΡΠ΅ΡΠ΅Π½ΡΡΡ "ΠΡΠΎΠ±Π»Π΅ΠΌΠΈ Ρ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²ΠΈ ΡΡΠ²ΠΎΡΠ΅Π½Π½Ρ Π΅ΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΡΠ½Π°Π½ΡΠΎΠ²ΠΎΠ³ΠΎ ΠΌΠ΅Ρ
Π°Π½ΡΠ·ΠΌΡ". Π ΠΎΠ·Π³Π»ΡΠ½ΡΡΠΎ ΠΏΡΠΎΠ±Π»Π΅ΠΌΠΈ, ΠΏΠΎΠ²'ΡΠ·Π°Π½Ρ Π· ΡΠΎΠ·Π²ΠΈΡΠΊΠΎΠΌ Π΅ΠΊΠΎΠ½ΠΎΠΌΡΡΠ½ΠΎΡ ΡΠ΅ΠΎΡΡΡ ΡΠ° Π³ΠΎΡΠΏΠΎΠ΄Π°ΡΡΡΠΊΠΎΡ ΠΏΡΠ°ΠΊΡΠΈΠΊΠΈ; Π΅ΠΊΠΎΠ½ΠΎΠΌΡΡΠ½Ρ ΠΏΡΠΎΠ±Π»Π΅ΠΌΠΈ ΡΠ½Π½ΠΎΠ²Π°ΡΡΠΉΠ½ΠΎΠ³ΠΎ ΡΠΎΠ·Π²ΡΡΠΊΡ Π³ΠΎΡΠΏΠΎΠ΄Π°ΡΡΡΠΊΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΡ Ρ ΠΏΡΠ΄ΠΏΡΠΈΡΠΌΡΡΠ²; ΠΏΡΠΎΠ±Π»Π΅ΠΌΠΈ Ρ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²ΠΈ ΡΡΠ²ΠΎΡΠ΅Π½Π½Ρ Π΅ΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎ ΡΡΠ½ΠΊΡΡΠΎΠ½ΡΡΡΠΎΠ³ΠΎ ΡΡΠ½Π°Π½ΡΠΎΠ²ΠΎΠ³ΠΎ ΠΌΠ΅Ρ
Π°Π½ΡΠ·ΠΌΡ ΡΠ½Π½ΠΎΠ²Π°ΡΡΠΉΠ½ΠΎΠ³ΠΎ ΡΠΎΠ·Π²ΠΈΡΠΊΡ Π£ΠΊΡΠ°ΡΠ½ΠΈ; ΡΠ΅ΠΎΡΠ΅ΡΠΈΡΠ½Ρ ΠΏΡΠ°ΠΊΡΠΈΡΠ½Ρ ΠΏΠΈΡΠ°Π½Π½Ρ ΠΌΠΎΠ΄Π΅Π»ΡΠ²Π°Π½Π½Ρ Π² ΡΠΏΡΠ°Π²Π»ΡΠ½Π½Ρ ΡΠ½Π½ΠΎΠ²Π°ΡΡΠΉΠ½ΠΈΠΌ ΡΠΎΠ·Π²ΠΈΡΠΊΠΎΠΌ Π΅ΠΊΠΎΠ½ΠΎΠΌΡΠΊΠΈ; ΠΏΠΈΡΠ°Π½Π½Ρ ΡΠΎΠ·Π²ΠΈΡΠΊΡ Π±ΡΠ·Π½Π΅Ρ-ΠΎΡΠ²ΡΡΠΈ ΡΠΊ ΡΠ°ΠΊΡΠΎΡΠ° ΡΠ½Π½ΠΎΠ²Π°ΡΡΠΉΠ½ΠΎΠ³ΠΎ ΡΠΎΠ·Π²ΠΈΡΠΊΡ Π΅ΠΊΠΎΠ½ΠΎΠΌΡΠΊΠΈ ΡΠ΅Π³ΡΠΎΠ½Ρ.ΠΡΠΎΠ±Π»Π΅ΠΌΠΈ Ρ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²ΠΈ ΡΡΠ²ΠΎΡΠ΅Π½Π½Ρ Π΅ΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΡΠ½Π°Π½ΡΠΎΠ²ΠΎΠ³ΠΎ ΠΌΠ΅Ρ
Π°Π½ΡΠ·ΠΌΡ / ΠΠ°ΡΠ΅ΡΡΠ°Π»ΠΈ ΡΡΡΠ΄Π΅Π½ΡΡΡΠΊΠΎΡ Π½Π°ΡΠΊΠΎΠ²ΠΎΡ ΠΊΠΎΠ½ΡΠ΅ΡΠ΅Π½ΡΡΡ (ΠΠ½ΡΠΏΡΠΎΠΏΠ΅ΡΡΠΎΠ²ΡΡΠΊ, 21-23 Π±Π΅ΡΠ΅Π·Π½Ρ 2012 ΡΠΎΠΊΡ). β ΠΠ½ΡΠΏΡΠΎΠΏΠ΅ΡΡΠΎΠ²ΡΡΠΊ: ΠΠΠΠ Β«ΠΠΠ£Β», 2012. β Ρ. 106
Mesoscopic modeling of spacing and grain selection in columnar dendritic solidification: Envelope versus phase-field model
We investigate and assess the capability of the mesoscopic envelope model of dendritic solidification to represent the growth of columnar dendritic structures. This is done by quantitative comparisons to phase-field simulations in two dimensions. While the phase-field model resolves the detailed growth morphology at the microscale, the mesoscopic envelope model describes a dendritic grain by its envelope. The envelope growth velocities are calculated by an analytical dendrite-tip model and matched to the numerical solution of the solute concentration field in the vicinity of the envelope. The simplified representation of the dendrites drastically reduces the calculation time compared to phase field. Larger ensembles of grains can therefore be simulated. We show that the mesoscopic envelope model accurately reproduces the evolution of the primary branch structure, the undercooling of the dendrite tips, and the solidification path in the columnar mushy zone. We further show that it can also correctly describe the transient adjustments of primary spacing, both by spacing increase due to elimination of primary branches and by spacing reduction due to tertiary rebranching. Elimination and tertiary rebranching are also critical phenomena for the evolution of grain boundaries between columnar grains that have a different crystallographic orientation with respect to the temperature gradient. We show that the mesoscopic model can reproduce the macroscopic evolution of such grain boundaries for small and moderate misorientation angles, i.e., up to 30°. It is therefore suitable for predicting the texture of polycrystalline columnar structures. We also provide guidelines for the calibration of the main parameters of the mesoscopic model, required to obtain reliable predictions.ANR-11-LABX-0008/11-LABX-0008 - DAMAS - Design des Alliages Métalliques pour Allègement des Structures (2011) - German Space Agency DLR under Contract FKZ 50WM144
ΠΡΠΎΠ±Π»Π΅ΠΌΡ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π±Π»Π°Π³ΠΎΠΏΠΎΠ»ΡΡΠΈΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ ΡΠΊΠΎΠ»ΠΎΠ³ΠΈΠ·Π°ΡΠΈΠΈ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ ΠΈ ΠΏΡΠΎΠΌΡΡΠ»Π΅Π½Π½ΡΡ ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΠΉ
ΠΡΠΎΠ²Π΅Π΄Π΅Π½ Π°Π½Π°Π»ΠΈΠ· ΠΊΠ°ΡΠ΅ΡΡΠ²Π° ΠΆΠΈΠ·Π½ΠΈ ΠΈ ΡΡΠΎΠ²Π½Ρ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π±Π»Π°Π³ΠΎΠΏΠΎΠ»ΡΡΠΈΡ Π³ΡΠ°ΠΆΠ΄Π°Π½ Π² ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΌ ΠΌΠΈΡΠ΅. Π‘ΠΎΠ±ΡΠ°Π½Ρ ΡΡΠ°ΡΠΈΡΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ Π΄Π°Π½Π½ΡΠ΅, Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΊΠΎΡΠΎΡΡΡ
ΡΠ΄Π΅Π»Π°Π½Ρ Π²ΡΠ²ΠΎΠ΄Ρ ΠΎ ΡΠ΅Π»Π΅ΡΠΎΠΎΠ±ΡΠ°Π·Π½ΠΎΡΡΠΈ ΠΎΡΠ΅Π½ΠΊΠΈ Π±Π»Π°Π³ΠΎΠΏΠΎΠ»ΡΡΠΈΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Π² ΡΠ»ΠΎΠΆΠΈΠ²ΡΠΈΡ
ΡΡ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π΅Π½Π½ΠΎ-ΡΠ΅Ρ
Π½ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΡΠ»ΠΎΠ²ΠΈΡΡ
. ΠΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠ² ΠΎΡΠ΅Π½ΠΊΠΈ Π±Π»Π°Π³ΠΎΠΏΠΎΠ»ΡΡΠΈΡ Π³ΡΠ°ΠΆΠ΄Π°Π½ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»Π΅ΠΉ ΠΈ ΠΊΡΠΈΡΠ΅ΡΠΈΠ΅Π². ΠΡΠΎΠ²Π΅Π΄Π΅Π½Π° ΠΎΡΠ΅Π½ΠΊΠ° ΠΊΠ°ΡΠ΅ΡΡΠ²Π° ΠΆΠΈΠ·Π½ΠΈ Π³ΡΠ°ΠΆΠ΄Π°Π½ Π ΠΎΡΡΠΈΠΈ. ΠΡΡΡΠ΅ΡΡΠ²Π»Π΅Π½ΠΎ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ Π±Π»Π°Π³ΠΎΡΠΎΡΡΠΎΡΠ½ΠΈΡ Π³ΡΠ°ΠΆΠ΄Π°Π½ Ρ ΡΡΠ΅ΡΠΎΠΌ Π³Π΅Π½Π΄Π΅ΡΠ½ΠΎΠΉ ΠΏΡΠΈΠ½Π°Π΄Π»Π΅ΠΆΠ½ΠΎΡΡΠΈ, ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΈ ΡΠΎΡΠΈΠ°Π»ΡΠ½ΠΎ-ΠΏΠΎΠ»ΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΡΡΡΠ°Π½. ΠΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Ρ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π±Π»Π°Π³ΠΎΠΏΠΎΠ»ΡΡΠΈΡ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ°
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