Reaction of electrochemically generated radical anions with phosphorylated ureas

1. In the presence of phosphorylated ureas, oxygen, nitrobenzene, benzophenone, and anthracene are reduced in DMF on a mercury cathode according to the ECE mechanism, and the rate constants k2 and activation energies of the included chemical reaction were calculated. 2. Based on the kinetic data, the scheme of the process with included protonation of the radical anion in which any of the hydrogen atoms in the NH fragments of the PU molecules can participate was proposed. © 1988 Plenum Publishing Corporation

ПРОБЛЕМЫ ФОРМИРОВАНИЯ ИННОВАЦИОННОГО ПАРКА СЕЛЬСКОХОЗЯЙСТВЕННЫХ ТРАКТОРОВ РОССИИ

In the market of agricultural tractors of Russia in 2013 were 900 domestic models, or 3.4 percent. There were produced 7655 tractors, 6707 from which were foreign models. It was revealed that purchasing power of the agricultural organizations appears at profitability not less than 20 percent. Because this indicator is 5.2-11.7 percent lower, agricultural enterprises are not able to turn over their fleets. The authors have presented the forecast of development of tractor fleet till 2020 taking into account the solution of national tasks, including import substitution and dynamics of the annual purchases providing its realization. Methodology of development of the State program of food import substitution based on tractor fleet revival as conditions of self-sustainability of Russia was proposed. A role of tractor fleet as multiplier in development of the mechanized agricultural production was revealed. The first-priority problem is working out of tractors of economic category.На рынке сельскохозяйственных тракторов России в 2013 г. отечественные модели составили 0,9 тыс.ед., или 3,4 процента. Было произведено 7655 тракторов, 6707 из которых представлены иностранными моделями. Выявили, что покупательная способность сельскохозяйственных организаций появляется при рентабельности не менее 20 процентов. Так как этот показатель на 5,2-11,7 процента ниже, сельхозпредприятия не способны полноценно обновлять парк. Представили прогноз развития тракторного парка до 2020 г. с учетом решения национальных задач, включая импортозамещение и динамику годовых закупок, обеспечивающих его реализацию. Предложили Методологию разработки Государственной программы продовольственного импортозамещения на основе возрождения тракторного парка как условия самодостаточности России. Выявили роль тракторного парка как мультипликатора в развитии механизированного сельхозпроизводства. В качестве первоочередной представили задачу разработки тракторов экономической категории

Further progress in the study of epsilon iron oxide in archaeological baked clays

The occurrence of ε-Fe2O3 in archaeological samples that have been subjected to high temperatures is gradually being detected by the use of micrometric structural characterization techniques. This work provides new information by revealing that the ε-Fe2O3 is formed as a response to temperature, the aggregation state and the position within the baked clay with respect to the nearest heat source. In addition, depending mainly on the atmospheric environment, the temperature reached by the combustion structure, the distance from the heating source and the particle aggregation, other iron oxide magnetic phases are produced. In the baked clay studied here, hematite is found over the whole range of samples studied but its magnetic contribution is negligible. Magnetite is observed at the sample surface, probably due to local atmospheric environment closest to the combustion source. Maghemite is found at all depths up to 6 cm below the sample surface. ε-Fe2O3 has a limited distribution, found within 2–3 cm of the sample surface. Furthermore, the viability of this compound as a palaeofield marker has been evaluated in both archaeological and synthetic samples. The results indicate that ε-Fe2O3 is able to register the direction of the magnetic field. Linear palaeointensity plots have been obtained in synthetic samples, although the value of the palaeofield could be, sometimes, overestimated

ПРОБЛЕМЫ ФОРМИРОВАНИЯ ИННОВАЦИОННОГО ПАРКА СЕЛЬСКОХОЗЯЙСТВЕННЫХ ТРАКТОРОВ РОССИИ

Formation of tractors park and its perspective development are carried out on the basis of realization and improvement of the scientifically based types range constructed on a traction classification sign which conforms to requirements of agricultural production when performing two main conditions: full meeting the requirements for various standard sizes of tractors applicable to conditions of the corresponding zones of Russia and continuous reproduction and development of tractor fleet, both by quantity of efficient machinery and its structure. The developed types range practically runs the gamut of organizational and economic and climatic conditions, and also all range of forms of the organizations using machinery, beginning from individual consumers, small and large rent and contract collectives and finishing large-scale enterprises and their associations. Federal Service of State Statistics (Rosstat) information about a steady tendency of fleet reduction was used for studying of regularities of development of tractor fleet. This information was added by analytical synthesis of data about the annual brand purchases in the Russian market of agricultural tractors. The developed database shows a share of the tractors in fleets of agricultural organizations, which are used over depreciation term, and also minimum necessary number of new machines introduction for formation of volume of tractors with limit age and the total quantity of tractors necessary for minimization of set of expenses. It was established that it is possible to estimate visually the developed quantitative and age structure of tractors fleet and to predict its development on prospect by worked out database representing set of annual tractors brand lines purchasing.Формирование парка тракторов и его перспективное развитие осуществляются на основе реализации и совершенствования научно обоснованного типажа, построенного по тяговому классификационному признаку, который соответствует требованиям сельхозпроизводства при выполнении двух основных условий: полное обеспечение потребности в различных типоразмерах тракторов применительно условиям соответствующих зон России и постоянное воспроизводство и развитие тракторного парка, как по количеству работоспособной техники, так и по его структуре. Разработанный типаж охватывает практически весь диапазон организационно-хозяйственных и климатических условий, а также весь спектр форм организаций, использующих технику, начиная от индивидуальных потребителей, мелких и крупных арендных и подрядных коллективов и кончая крупными хозяйствами и их объединениями. Для изучения закономерностей развития тракторного парка информацию Росстат об устойчивой тенденции сокращения парка дополнили путем аналитического обобщения данных о годовых помарочных закупках на российском рынке сельскохозяйственных тракторов. Показали, что разработанная база данных отражает долю тракторов в парке СХО, используемых сверх срока амортизации, а также минимально необходимое количество введения новых машин для формирования объема тракторов предельного возраста и общего количества тракторов, необходимого для минимизации совокупности затрат. Установили, что наглядно оценить сложившуюся количественно-возрастную структуру парка тракторов и прогнозировать ее развитие на перспективу возможно при помощи разработанной базы данных, представляющей собой совокупность годовых помарочных закупочных линеек тракторов

Polarity in ZnO nanowires: A critical issue for piezotronic and piezoelectric devices

The polar and piezoelectric nature of the wurtzite structure of ZnO nanowires with a high aspect ratio at nanoscale dimensions is of high interest for piezotronic and piezoelectric devices, but a number of issues related to polarity are still open and deserve a particular attention. In this context, chemical bath deposition offers a unique opportunity to select the O- or Zn-polarity of the resultant nanowires and is further compatible with the fabrication processes of flexible devices. The control and use of the polarity in ZnO nanowires grown by chemical bath deposition opens a new way to greatly enhance the performance of the related piezotronic and piezoelectric devices. However, polarity as an additional tunable parameter should be considered with care because it has a strong influence on many processes and properties. The present review is intended to report the most important consequences related to the polarity in ZnO nanowires for piezotronic and piezoelectric devices. After introducing the basic principles involving crystal polarity in ZnO, a special emphasis is placed on the effects of polarity on the nucleation and growth mechanisms of ZnO nanowires using chemical bath deposition, defect incorporation and doping, electrical contacts and device properties

Conditions of uniform distribution of current density in the deposition of metal coatings on wire

Translated from Stal' (1980) (pt.5) p. 415-416LD:5828.4F(M--26214) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo