Новые поступления электронной библиотеки
Nonleptonic kaon decays K → ππ and the matrix element of the K0−K¯ 0 transition were studied within the framework of the Quark Conned Model using eective four-quark Hamiltonians. The role of intermediate hadronic states in the description of these processes was studied. It is shown that correct consideration of the intermediate scalar state f0(600) allows one to obtain the relation γ+− = ( Γ(KS→π +π−) Γ(K0→π+π0) = 433.84, which is close to the experimental value, which makes it possible to explain the ∆I = 1 2 rule. Account of intermediate scalar, pseudo scalar and axial vector states made it possible to obtain the mass dierence K0 L and K0 S ∆mLS = 3.25×10 −15GeV , which is in good agreement with the experimental value.
В работе приведены результаты исследований стойкости к контактному изнашиванию диффузионно-упрочненных слоев конструкционных сталей 35ХГСА и 40Х при пульсирующем воздействии на поверхность материалов напряжения величиной 1300 МПа. Выявлен механизм разрушения указанных слоев. Определены зависимости, отражающие интенсивность контактного изнашивания. Обоснованы рекомендации применения сталей 35ХГСА и 40Х в качестве материала заменителя стали XI2М для изготовления мелкоразмерного инструмента для холодной объемной
штамповки.
Рассмотрена целесообразность замены неизолированных проводов воздушных линий электропередачи на самонесущие изолированные. Показано, что изолированный провод может быть размещен на уже существующих опорах. Представлены результаты конечно-элементного моделирования устройств воздушной линии электропередачи под действием статических и динамических нагрузок в среде программы ANSYS. Приведены результаты расчетов колебаний проводов, вызванных резким изменением нагрузки.
Исследовано влияние длительности нитроцементации и цементации на струрообразование поверхностных слоев конструкционных экономно-легированных сталей 40Х и ЗОХГСА при 8-ми и 12-ти часовом насыщении. Проанализировано влияние криогенной обработки после закалки на структуру сталей 40Хи ЗОХГСА.
The influence ofthe duration ofnitriding and carburizing on structureformation surface layers ofcon struction economically-alloyed steels 40Cr and 30CrMnSiA were investigated. The influence of cryogenic treatment on the structure after hardening steels 40Cr and 30CrMnSiA were analyzed.
The results of the study contact endurance of steel W6Mo5. It is shown that the destruction of the surface layer takes place by alternating two steps. At the first stage of hardening of the material flows, and the second the formation of surface defects in work-hardened layer depth.
In this paper, a novel asymmetric non-premixed combustor with well-defined geometric boundary is provided to enhance air/fuel mixing and improve flame stability. A comprehensive numerical model, which coupled with large-eddy simulation using a modified Sub-grid scales kinetic energy model and second-order moment combustion model using a simplified four steps chemical reaction mechanism, for non-premixed combustion in a semi-confined space is established. The results show that four isolated vortices characterized by the features of strongly rotating and tangential shear stress are formed in the corner region of combustor. With the increases of inlet gas velocity, the flame blow off do not happen and the average temperature in the combustor remain mostly uniform low and well distributed. Combustion intensity, vortex structures forming and shedding which involves turbulent mixing, chemical reaction and flame propagation is affected by the strongly swirling flow field structure.
Multi-energy complementary and coordinative operation can effectively improve the comprehensive utilization of energy, which can not only promote the consumption of renewable energy, but also effectively reduce energy costs and improve the reliability of energy use. The electric-thermal coupling multi-energy system is an important form of multi-energy complementary coordination, which is prevalent and continues to develop in the northern region of China. Therefore, the study of multi-time-scale modeling of electrothermal coupled energy network is of great significance to improve the anti-jamming ability of the whole system and strengthen the interaction between systems.
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