146 research outputs found
Observation of ferromagnetic resonance in strontium ruthenate (SrRuO3)
We report the observation of ferromagnetic resonance (FMR) in SrRuO3 using
the time-resolved magneto-optical Kerr effect. The FMR oscillations in the
time-domain appear in response to a sudden, optically induced change in the
direction of easy-axis anistropy. The high FMR frequency, 250 GHz, and large
Gilbert damping parameter, alpha ~ 1, are consistent with strong spin-orbit
coupling. We find that the parameters associated with the magnetization
dynamics, including alpha, have a non-monotonic temperature dependence,
suggestive of a link to the anomalous Hall effect.Comment: submitted to Phys. Rev. Let
Determination of the spin-flip time in ferromagnetic SrRuO3 from time-resolved Kerr measurements
We report time-resolved Kerr effect measurements of magnetization dynamics in
ferromagnetic SrRuO3. We observe that the demagnetization time slows
substantially at temperatures within 15K of the Curie temperature, which is ~
150K. We analyze the data with a phenomenological model that relates the
demagnetization time to the spin flip time. In agreement with our observations
the model yields a demagnetization time that is inversely proportional to T-Tc.
We also make a direct comparison of the spin flip rate and the Gilbert damping
coefficient showing that their ratio very close to kBTc, indicating a common
origin for these phenomena
Π£ΡΠ΅Ρ ΠΈ Π°Π½Π°Π»ΠΈΠ· Π΄Π²ΠΈΠΆΠ΅Π½ΠΈΡ ΠΎΡΠ½ΠΎΠ²Π½ΡΡ ΡΡΠ΅Π΄ΡΡΠ² Π½Π° Π½Π΅ΡΡΠ΅Π³Π°Π·ΠΎΠ΄ΠΎΠ±ΡΠ²Π°ΡΡΠ΅ΠΌ ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΠΈ
Π£ΡΠ΅Ρ ΠΈ Π°Π½Π°Π»ΠΈΠ· Π΄Π²ΠΈΠΆΠ΅Π½ΠΈΡ ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
ΡΡΠ΅Π΄ΡΡΠ² Π½Π° ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΠΈ. Π ΡΠ°Π±ΠΎΡΠ΅ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡΡΡ ΠΏΠΎΠ½ΡΡΠΈΠ΅ ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
ΡΡΠ΅Π΄ΡΡΠ², ΠΈΡ
ΠΊΠ»Π°ΡΡΠΈΡΠΈΠΊΠ°ΡΠΈΡ, Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΠΎΠΎΠ±ΠΎΡΠΎΡ, ΠΏΠ΅ΡΠ²ΠΈΡΠ½ΡΠ΅ Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΡ ΠΏΠΎ ΠΎΡΠ½ΠΎΠ²Π½ΡΠΌ ΡΡΠ΅Π΄ΡΡΠ²Π°ΠΌ ΠΈ ΠΏΡΠ°Π²ΠΈΠ»ΡΠ½ΠΎΠ΅ ΠΈΡ
Π·Π°ΠΏΠΎΠ»Π½Π΅Π½ΠΈΠ΅.Accounting and analysis of the movement of fixed assets in the enterprise. The paper discusses the concept of fixed assets, their classification, document flow, primary documents on fixed assets and their correct filling
Late consequences of early selection: when memory monitoring backfires
At retrieval, people can adopt a retrieval orientation by which they recreate the mental operations used at encoding. Monitoring by retrieval orientation leads to assessing all test items for qualities related to the encoding task, which enriches foils with some of the qualities already possessed by targets. We investigated the consequences of adopting a retrieval orientation under conditions of repeated monitoring of the same foils. Participants first processed foils in the context of one of two tests encouraging different retrieval orientations. The foils were then re-used on a subsequent test in which retrieval orientation either matched or mismatched that adopted on the first test. In the aggregate data, false alarms for repeated foils were higher when there was a match between the retrieval orientations on both tests. This demonstrates that when retrieval orientation enriches foils with target-like characteristics, it can backfire when repeated monitoring of the same foils is required
Tumour homing and therapeutic effect of colloidal nanoparticles depend on the number of attached antibodies
Active targeting of nanoparticles to tumours can be achieved by conjugation with specific antibodies. Specific active targeting of the HER2 receptor is demonstrated in vitro and in vivo with a subcutaneous MCF-7 breast cancer mouse model with trastuzumab-functionalized gold nanoparticles. The number of attached antibodies per nanoparticle was precisely controlled in a way that each nanoparticle was conjugated with either exactly one or exactly two antibodies. As expected, in vitro we found a moderate increase in targeting efficiency of nanoparticles with two instead of just one antibody attached per nanoparticle. However, the in vivo data demonstrate that best effect is obtained for nanoparticles with only exactly one antibody. There is indication that this is based on a size-related effect. These results highlight the importance of precisely controlling the ligand density on the nanoparticle surface for optimizing active targeting, and that less antibodies can exhibit more effect
Design, calibration, and performance of the MINERvA detector
The MINERvA(6) experiment is designed to perform precision studies of neutrino-nucleus scattering using nu(mu) and (nu) over bar (mu) neutrinos incident at 1-20 GeV in the NuMI beam at Fermilab. This article presents a detailed description of the MINERvA detector and describes the ex situ and in situ techniques employed to characterize the detector and monitor its performance. The detector is composed of a finely segmented scintillator-based inner tracking region surrounded by electromagnetic and hadronic sampling calorimetry. The upstream portion of the detector includes planes of graphite, iron and lead interleaved between tracking planes to facilitate the study of nuclear effects in neutrino interactions. Observations concerning the detector response over sustained periods of running are reported. The detector design and methods of operation have relevance to future neutrino experiments in which segmented scintillator tracking is utilized. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/)
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