493 research outputs found
Devaney Chaos on a Set-valued Map and Its Inverse Limit
We study relationships between a set-valued map and its inverse limits about
the notion of periodic point set, transitivity, sensitivity and Devaney chaos.
Density of periodic point set of a set-valued map and its inverse limits
implies each other. Sensitivity of a set-valued map and its inverse limits does
not imply each other. Transitivity and Devaney chaos of generalized inverse
limits implies the corresponding property of a set-valued map
Electronic phase diagram of NdFe1-xRhxAsO
We report on the electrical resistivity, thermoelectric power and electronic
phase diagram of rhodium-doped NdFeAsO. Rhodium doping suppresses the
structural phase transition and spin density wave observed in the undoped
material, and superconductivity emerges at x close to 0.05, despite the
distortion of FeAs4 tetrahedra induced by the large size difference between Rh
and Fe elements. The Tc(x) curve is dome-like, and the highest Tc is reached at
x = 0.1, with Tconset = 18K. An upturn of the electrical resistivity above Tc
has been observed, with a Kondo like behaviour above Tc and a Fermi-liquid
behaviour close to room temperature.Comment: 17 pages, 10 figure
Electronic phase diagram of NdFe1-xRhxAsO
We report on the electrical resistivity, thermoelectric power and electronic
phase diagram of rhodium-doped NdFeAsO. Rhodium doping suppresses the
structural phase transition and spin density wave observed in the undoped
material, and superconductivity emerges at x close to 0.05, despite the
distortion of FeAs4 tetrahedra induced by the large size difference between Rh
and Fe elements. The Tc(x) curve is dome-like, and the highest Tc is reached at
x = 0.1, with Tconset = 18K. An upturn of the electrical resistivity above Tc
has been observed, with a Kondo like behaviour above Tc and a Fermi-liquid
behaviour close to room temperature.Comment: 17 pages, 10 figure
Анализ современных методов ремонта дефектных участков магистральных нефтепроводов
Объектом исследования является дефекты магистральных нефтепроводов и способы и особенности их устранения. Цель работы: выявление эффективных методов ремонта дефектных участков магистрального нефтепровода. В процессе работы проводилось изучение основных распространенных дефектов и основных методов их устранения. Подробно рассмотрен ремонт магистрального нефтепровода с помощью муфт типа П-1 и П-2 методом постоянного ремонта, восстанавливающим несущую способность дефектного участка нефтепровода до уровня бездефектного участка на все время его дальнейшей эксплуатации.
В результате изучения способов ремонта нефтепровода сделан вывод, что применение таких методов ремонта как заварка, шлифовка, установка ремонтной конструкции в отличие от вырезки дефекта (замены катушки) и капитального ремонта нефтепровода с заменого трубопровода производится без остановки перекачки нефти, что дает ряд преимуществ.The object of research is the main oil pipelines defects and ways and features to address them. Objective: To identify effective methods for repairing defective portions of the main oil pipeline. In the process, carried out the study of basic common defects and basic methods of their elimination. Considered in detail the main oil pipeline repair using couplings type P-1 and P-2 by the method of constant repair, reducing the carrying capacity of the defective section of the pipeline to the level of a defect-free area for the duration of its intended use. As a result of studying ways to repair the pipeline concluded that the use of such methods of repairs such as welding, grinding, installation repair structure in contrast
Can ChatGPT-like Generative Models Guarantee Factual Accuracy? On the Mistakes of New Generation Search Engines
Although large conversational AI models such as OpenAI's ChatGPT have
demonstrated great potential, we question whether such models can guarantee
factual accuracy. Recently, technology companies such as Microsoft and Google
have announced new services which aim to combine search engines with
conversational AI. However, we have found numerous mistakes in the public
demonstrations that suggest we should not easily trust the factual claims of
the AI models. Rather than criticizing specific models or companies, we hope to
call on researchers and developers to improve AI models' transparency and
factual correctness
Анализ и исследование условий образования и эффективности мер предотвращения солеотложений при эксплуатации скважин на Шингинском нефтяном месторождении (Томская область)
Предотвращение солеобразования оборудования эксплуатационных скважин. Объектом являются добывающие и нагнетательные скважины, пробы попутно-добываемой и нагнетаемой воды. Целью работы является увеличения межремонтного периода работы осложнённого фонда скважин и разработки рекомендаций по увеличению срока защиты подземного оборудования. В процессе исследования проводились анализ химического состава и определение типа попутно добываемой, пластовой и нагнетаемой воды, изучение внутренней структуры солеотложения, прогноз вероятности образования солеотложений в подземном оборудовании скважин, анализ экономической эффективности за счет изменения межремонтного периода работы скважин.Scale formation is a major problem in the oil industry. They may occur downhole or in surface facilities. The formations of these scales plug production lines and equipment and impair fluid flow. Their consequence could be production equipment failure, emergency shutdown, increased maintenance cost, and an overall decrease in production efficiency. The failure of production equipment and instruments could result in safety hazards
Устойчивость процесса зажигания полимерного материала горячей частицей
As a result of the numerical investigation of a typical polymeric material ignition by a local energy source with limited heat content it has been determined three modes: gasification without ignition followed by pyrolysis stop, stable ignition, and unstable ignition. The mathematical model of the process takes in account conductive heat transfer and thermal decomposition in condensed phase, diffusion-convective heat and mass transfer and gaseous pyrolysis products oxidation of polymeric material in air
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