Технологические особенности формирования катодных узлов автоэмиссионных и туннельных нано- и микроприборов
The article is devoted to the investigation of the structure of pressed palladium-barium cathodes. These cathodes are made from a polycrystalline palladium matrix with inclusions of the particles of the activator phase Pd5Ba. The high efficiency and durability of pressed palladiumbarium cathodes is ensured by the formation of an active-emission BaO layer on the working surface. The active metal Ba comes from the volume to the surface by diffusion of atoms on the defects of the crystal structure of the palladium matrix. When comparing the electrical parameters of the cathodes, the matrices of which were made from the same fractions but different batches of palladium powder, a considerable spread of electrical parameters was established. There were also revealed significant differences in the roughness of the cathode working surface. These differences affect the uniformity and stability of the emission current. This indicates the need for a detailed study of the characteristics of the initial palladium powder and their effect on the structure of the sintered material, and, consequently, on the physicomechanical properties of its surface. In this paper, the morphological features of eight batches of palladium powder in the initial state and after the purification annealing were studied by the method of electron microscopy. Significant differences in the form of particles and agglomerates of powder from different batches have been revealed. A metallographic analysis of microsections of the palladium samples prepared by solidphase sintering was carried out. The influence of the morphological features of the particles of the initial powder on the grain size and the mechanical properties of the sintered compact is determined. Studies have shown that to obtain a compact palladium with reproducible and predictable properties, stability of the morphological characteristics of the original powder is necessary.
The diffusion penetrability and thermal conductivity of the interphase interface in the Mo(20mсm)–Ni(1 mm) system is studied during thermal annealing and high-energy electron irradiation. It is shown that the thermal conductivity can be used to study the diffusion process of forming a quasi-stationary state at the interface.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.