Charge screening and magnetic anisotropy in metallic rare-earth systems

The calculation of magnetic anisotropy constants is performed beyond the point charge model for a continuous charge density distribution of screening conduction electrons. An important role of the non-uniform electron density, in particular, of the Friedel oscillations, in the formation of crystal field is demonstrated. Such effects can modify strongly the effective ion (impurity) charge and even change its sign. This enables one to justify the anion model, which is often used at discussing experimental data on hydrogen-containing systems. Possible applications to the pure rare-earth metals and RCo5 compounds are discussed. The deformation of magnetic structure near the interstitial positive muon owing to the strong local anisotropy, and the corresponding contribution to the dipole field at the muon are considered.Comment: 10 pages, RevTeX, 3 figure

Состав отходящих газов при каталитическом синтезе углеродных наноматериалов при пиролитическом разложении пропан-бутановой смеси

It is known that during the process of carbon nanomaterials synthesis, gaseous products and various unknown hydrocarbons are formed. Thus, the production of carbon nanomaterials could damage the environment. A detailed analysis of all gaseous products during the pyrolysis process is needed in order to clarify the nature of the formed substances and to control the technological characteristics of the catalyst. The chemical composition study of exhaust gases was made on the facility of propane-butane mixture pyrolysis for the carbon nanomaterial synthesis. The analysis of 16 polycyclic aromatic hydrocarbons (PAHs) of the extracts is made using a gas chromatography-mass spectrometry method. A quantitative analysis of gases was made by gas chromatography coupled with a heat conduction detector and a flame ionization detector. It was established that the concentrations of some PAHs exceed 14, 20, 90 and 100 times much as a maximum permissible concentration in the air. It was found that the appropriate devices of carbon nanomaterial production should be used in order to eliminate the PAHs that are formed.Анализ отходящих газов установки пиролиза легких углеводородов в процессе синтеза углеродных наноматериалов является актуальной задачей не только для оценки количества образующихся вредных веществ, но и для обеспечения наибольшей производительности реактора и максимальной степени конверсии исходного сырья. Методом газовой хроматографии проведен качественный и количественный анализ отходящих газов: неконденсируемых газообразных фракций и адсорбируемых ароматических углеводородов. В результате экспериментов было установлено, что основными компонентами отходящих газов являются водород и метан. В соответствии с утвержденной в Республике Беларусь методикой измерены значения 16 полициклических ароматических углеводородов, обнаруженных в отходящих газах. Проведено сравнение полученных значений с нормативными предельно допустимыми концентрациями канцерогенов в воздухе. Установлено, что концентрации пирена, фенантрена, аценафтилена, аценафтена превышают норму в 1,5–6 раз, а содержание таких токсикантов, как бенз(а)антрацен, антрацен, бенз(а)пирен и дибенз(а,h)антрацен значительно превышают норму. Полученная информация позволяет оценить степень опасности для экологии и возможный вклад таких установок в загрязнение окружающей среды, а также прогнозировать защитные меры по снижению вредного воздействия

The response of introduced initial material to dry conditions

Here has been carried out the study of ten parental forms of maize hybrids in moisture supplied conditions (All-Russian RI of maize, Pyatigorsk) and in dry conditions (All-Russian RI of Grain crops, Zernograd) according to the main economic-valuable traits, i.e. grain productivity, harvesting moisture of grain, a length of the period ‘sprouts-flowering’, lodging, infection with blister smut, infertility, a plant height and a height of cob attachment. The moisture supply differed in 2014 and 2016 that resulted in significant decrease of average productivity of the studied form in a dry trial. In 2015 the same moisture conditions in both trials resulted in the same amount of productivity of the studied forms. There have been determined such parental forms with high indexes of drought tolerance as ‘Istok S’(36.0%), ‘Mirt M’(44.9%), ‘Malvina S’(39.3%), ‘Verbena SD’(39.2%) and ‘Maya M’(39.7%). They are characterized with high indexes of main economic-valuable traits in dry conditions: grain productivity of 3.16-4.41 t/ha, harvesting moisture of grain of 11.3-14.9%, a height of cob attachment of 78.0-87.0cm, infection with blister smut 0-2.2%, lodging of 0.3-3.7%. The obtained parental forms are the promising ones for maize hybridization in the Rostov region characterized with unstable humidity. The correlation between an index of drought tolerance and plant infertility has been established. It has been recommended to use the data received in the years with contrast moisture supply for calculation of the index of drought tolerance