Effect of radiation heating on the creep of polymeric materials

Strength of Materials -     

On scientometrical characteristics on information activities of leading scientists

A comparative analysis of the information activities of leading scientists has been carried out, including 5 Soviet chemists and 5 foreign ones, and 8 Soviet physicists, specialist in low temperature physics. Within chemists there has appeared a tendency to a new form of scientific activities, namely ephemeron teams which favour the production line mode of getting new information. In physics, the traditional scheme is preserved: leading scientists publish few articles and have few co-authors. The ephemeron teams produce an expanding information: new objects and processes are studied from the previously elaborated point of view. The specific average citation rate (number of references per number of papers) is a criterion for separating the publications of the intellectual industry from the pilot studies full of novel ideas.Repinted from: A. I. MIKHAILOV (Ed.), Problems of Information User Needs, All-Union Institute for Scientific and Technical Information, Moscow, 1973, p. 113–134.     

有机硅／三元乙丙橡胶共混研究

本文对有机硅／三元乙丙橡胶共混的相容性和共硫化进行了研究，探讨了共混比例、填料、助剂、工艺条件等因素对共混胶力学性能的影响。结果表明，提高共混胶的相容性和共硫化性，是获得性能优异产品的关键，从而使这一新型材料在新的领域广泛应用。     

汽车用水基密封胶的制备

通过对不同的填料和用量的选择，研制成了水基汽车密封胶，应用于轻型汽车的整体密封，具有以水替代溶剂，节约能源、减少污染、贮存期长、使用安全、价格低廉等待点。     

熟料细碎机在粉磨系统中的应用

JSP系列超慢速剪式水泥熟料细碎机，是上世纪90年代出现的新型熟料细碎节能技术。它吸收了国内外机械适用先进技术．采用超慢速剪切破碎原理．克服了影响水泥熟料破碎机使用寿命的5个因素．即：高线速度、耐磨件材质、机体结构、篦板的设计、熟料矿物组成的影响。完全实现了有效控制出料粒度长期稳定．具有破碎效率高、功耗极低、防尘好、易损件寿命长、费用低、维护简便等特点。     

余热制冷技术在玻璃工业中的应用探讨

介绍了两种蒸汽制冷设备的工作原理和特点,并对各自的运行状况作了比较,同时简要分析了在玻璃工业中利用余热制冷的可行性。     

Investigation into the formation of phases with a Ba<Subscript>2</Subscript>Ti<Subscript>9</Subscript>O<Subscript>20</Subscript>-type structure in the BaO-TiO<Subscript>2</Subscript> and BaO-SrO-TiO<Subscript>2</Subscript> systems

The mechanism of formation of barium titanate Ba₂Ti₉O₂₀ in the BaO-TiO₂ and BaO-SrO-TiO₂ systems is investigated using initial mixtures prepared by three methods, namely, mechanical grinding of the initial reactants, coprecipitation from aqueous solutions of salts, and the sol-gel technique. It is established that, irrespective of the preparation procedure, the formation of Ba₂Ti₉O₂₀ proceeds through the formation of the intermediate phases BaTi₄O₉ and BaTi₅O₁₁. The nature of the intermediate phases is determined by the homogeneity and dispersion of the initial mixture, as well as by the stability of the intermediate phase. The most optimum conditions for the synthesis of Ba₂Ti₉O₂₀ are provided by the formation of BaTi₅O₁₁ as an intermediate phase upon heat treatment of the coprecipitation products in the nanocrystalline state. The metastability and structural defects in the BaTi₅O₁₁ intermediate phase encourage a decrease in the temperature of the final heat treatment by 100–150°C in the course of the preparation of Ba₂Ti₉O₂₀ single-phase ceramics.     

Electro-oxidation of dimethyl ether on Pt/C and PtMe/C catalysts in sulfuric acid

The electro-oxidation of dimethyl ether (DME) on PtMe/Cs (Me = Ru, Sn, Mo, Cr, Ni, Co, and W) and Pt/C electro-catalysts were investigated in an aqueous half-cell, and compared to the methanol oxidation. The addition of a second metal enhanced the tolerance of Pt to the poisonous species during the DME oxidation reaction (DOR). The PtRu/C electro-catalyst showed the best electro-catalytic activity and the highest tolerance to the poisonous species in the low over-potential range (<0.55 V, 50 °C) among the binary electro-catalysts and the Pt/C, but at the higher potential (>ca. 0.55 V, 50 °C), the Pt/C behaved better than PtRu/C. The apparent activation energy for the DOR decreased in the order: PtRu/C (57 kJ mol⁻¹) > Pt₃Sn/C (48 kJ mol⁻¹) ≈ Pt/C (46 kJ mol⁻¹). On the other hand, the activation energy for the MOR showed a different turn, decreased in the following order: Pt/C (43 kJ mol⁻¹) > Pt₃Sn/C (35 kJ mol⁻¹) ≈ PtRu/C (34 kJ mol⁻¹). The temperature dependence of the DOR was greater than that of the oxidation of methanol (MOR) on the PtRu/C.