873 research outputs found
Strong spin-orbit coupling and magnetism in (111) (LaSr)(AlTa/SrTiO
Strong correlations, multiple lattice degrees of freedom, and the ease of
doping make complex oxides a source of great research interest. Complex oxide
heterointerfaces break inversion symmetry and can host a two dimensional
carrier gas, which can display a variety of coexisting and competing phenomena.
In the case of heterointerfaces based on SrTiO, many of these phenomena can
be effectively tuned by using an electric gate, due to the large dielectric
constant of SrTiO. Most studies so far have focused on (001) oriented
heterostructures; however, (111) oriented heterostructures have recently gained
attention due to the possibility of finding exotic physics in these systems due
their hexagonal surface crystal symmetry. In this work, we use
magnetoresistance to study the evolution of spin-orbit interaction and
magnetism in a new system, (111) oriented
(LaSr)(AlTa)/SrTiO. At more positive
values of the gate voltage, which correspond to high carrier densities, we find
that transport is multiband, and dominated by high mobility carriers with a
tendency towards weak localization. At more negative gate voltages, the carrier
density is reduced, the high mobility bands are depopulated, and weak
antilocalization effects begin to dominate, indicating that spin-orbit
interaction becomes stronger. At millikelvin temperatures, and gate voltages
corresponding to the strong spin-orbit regime, we observe hysteresis in
magnetoresistance, indicative of ferromagnetism in the system. Our results
suggest that in the (111)
(LaSr)(AlTa)/SrTiO system, low mobility
carriers which experience strong spin-orbit interactions participate in
creating magnetic order in the system.Comment: 15 pages, 3 figure
Electrostatic tuning of magnetism at the conducting (111) (LaSr)(AlTa)/SrTiO interface
We present measurements of the low temperature electrical transport
properties of the two dimensional carrier gas that forms at the interface of
(LaSr)(AlTa)/SrTiO (LSAT/STO) as
a function of applied back gate voltage, . As is found in (111)
LaAlO/SrTiO interfaces, the low-field Hall coefficient is
electron-like, but shows a sharp reduction in magnitude below 20 V,
indicating the presence of hole-like carriers in the system. This same value of
correlates approximately with the gate voltage below which the
magnetoresistance evolves from nonhysteretic to hysteretic behavior at
millikelvin temperatures, signaling the onset of magnetic order in the system.
We believe our results can provide insight into the mechanism of magnetism in
SrTiO based systems.Comment: 5 pages, 3 figure
Quantum Hall effect in InAsSb quantum wells at elevated temperatures
We have characterized the electronic properties of a high-mobility
two-dimensional electron system in modulation doped InAsSb quantum wells and
compare them to InSb quantum wells grown in a similar fashion. Using
temperature-dependent Shubnikov-de Haas experiments as well as FIR transmission
we find an effective mass of 0.022, which is lower
than in the investigated InSb quantum well, but due to a rather strong
confinement still higher than in the corresponding bulk compound. The effective
-factor was determined to be 21.9. These results are also
corroborated by band structure calculations. When spin polarizing
the electrons in a tilted magnetic field, the -factor is significantly
enhanced by electron-electron interactions, reaching a value as large as
= 60 at a spin polarization P = 0.75. Finally, we show that due to
the low effective mass the quantum Hall effect in our particular sample can be
observed up to a temperature of 60 K and we propose scenarios how to increase
this temperature even further.Comment: 12 pages, 15 figure
Neuroeconom?a agraria familiar: aplicaci?n de la Jerarqu?a de Patrones Neuronales Emocionales en el sector de fibra de alpaca y papa nativa en Per?
This study aims to analyze the neuroeconomic decision-making of small producers of alpaca fiber and native potato considering the Neural Pattern Hierarchy Theory and the Temporal Memory Model. The aim is to measure the impact on the correlation level of holistic competencies of innovation in The learning process based on entrepreneurship. To achieve this, experimental, transactional, correlational, and descriptive research was conducted with a sample of 88 individuals. A methodology for aligning emotional neural patterns was applied. The results show that (H1:Y0 > Y1) emphasizing alpaca fiber.Este estudio tiene como objetivo analizar las decisiones neuroecon?micas de peque?os productores de fibra de alpaca y papa nativa considerando la Teor?a de la Jerarqu?a de Patrones Neuronales y el Modelo de la Memoria Temporal. Se pretende medir el impacto en el nivel de correlaci?n de las competencias hol?sticas de innovaci?n en el proceso de aprendizaje basado en el emprendimiento. Para ello se realiz? una investigaci?n de tipo experimental, transaccional, correlacional y descriptiva con una muestra de 88 individuos. Se aplic? una metodolog?a de alineamiento de patrones neuronales emocionales. Los resultados muestran que (H1:Y0 > Y1), acentuando fibra de alpaca
Виробництво м’ясних сиров’ялених снеків: перспективи та конкуренто-спроможність
The article presents the results of the study of consumer expectations on the example of the “standard” sample of meat dries snacks. The purpose of the work is to study consumer expectations of raw meat products and to study the competitiveness of this product on the Ukrainian market, as well as the impact of quality on this indicator. Nutrition is one of the main determinants of human health. In recent years there has been a disturbance of the nutrition structure due to changes in the rhythm of life and a decrease in the consumption of biologically valuable nutrition components. Unfortunately, the accelerated pace of life of a modern person makes her resort to food on the go. To satisfy this need people can have such products as snacks. Snacks, as a rule, are ideal for solving this problem – It is available natural dry products ready for use and packaged in individual packaging, which allows them to be used anywhere and in all conditions. Meat snack products quite recently appeared on the domestic market and attracted the attention of the consumer as a protein-containing product. The evaluation and comparison of the competitiveness of meat snacks presented on the consumer market of Kyiv with a “standard” sample has been carried out. The study was conducted using statistical methods of quality assessment. Roasted meat snacks are a new product on the market of Ukrainians, but their popularity is growing. With the necessary balance between the indicators of economy, safety and consumer desirable organoleptic indicators, the profitability of this segment of food production will only increase. The research of the competitiveness of meat snacks proves that the consumer is interested in their purchase, and therefore producers should pay attention to the development of this type of products.У статті наведені результати дослідження споживчих очікувань на прикладі “еталонного” зразка м’ясних сиров’ялених снеків. Харчування – один із найголовніших факторів, що визначають здоров’я людини. В останні роки спостерігається порушення структури харчування, зумовлене зміною ритму життя і зниженням споживання біологічно цінних компонентів харчування. На жаль, прискорений темп життя сучасної людини, змушує її вдаватися до харчування на ходу. Задовольнити цю потребу людей можуть такі продукти як снеки. Снеки, як правило, ідеально підходять для вирішення цієї проблеми – це доступні натуральні сухі продукти, готові до вживання і розфасовані в індивідуальну упаковку, що дозволяє їх застосовувати в будь-якому місці і в будь-яких умовах. М’ясна снекова продукція досить недавно з’явилася на вітчизняному ринку і привернула до себе увагу споживача як білкововмісний продукт. Проведено оцінювання та порівняння конкурентоспроможності м’ясних снеків, які представлені на споживчому ринку м. Києва, з “еталонним” зразком. Дослідження проводилось з використанням статистичних методів оцінки якості. Сиров’ялені м’ясні снеки є новим продуктом на полицях українців, проте їх популярність набирає обертів. При дотриманні необхідного балансу між показниками економічності, безпечності та бажаними для споживача органолептичними показниками, рентабельність даного сегменту харчового виробництва буде лише зростати. Дослідження конкурентоспроможності м’ясних снеків доводить, що споживач зацікавлений в їх придбанні, а отже виробникам варто звернути увагу на розробку цього виду продукції
Ultrastructural and functional fate of recycled vesicles in hippocampal synapses
Efficient recycling of synaptic vesicles is thought to be critical for sustained information transfer at central terminals. However, the specific contribution that retrieved vesicles make to future transmission events remains unclear. Here we exploit fluorescence and time-stamped electron microscopy to track the functional and positional fate of vesicles endocytosed after readily releasable pool (RRP) stimulation in rat hippocampal synapses. We show that most vesicles are recovered near the active zone but subsequently take up random positions in the cluster, without preferential bias for future use. These vesicles non-selectively queue, advancing towards the release site with further stimulation in an actin-dependent manner. Nonetheless, the small subset of vesicles retrieved recently in the stimulus train persist nearer the active zone and exhibit more privileged use in the next RRP. Our findings reveal heterogeneity in vesicle fate based on nanoscale position and timing rules, providing new insights into the origins of future pool constitution
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