The research of the reaction of ethylbenzene with ozone in the environment of acetic acid

Изучена реакция этилбензола с озоном в среде ледяной уксусной кислоты. Показано, что, при температуре 10 ºС этилбензол реагирует с озоном преимущественно по бензольному кольцу с образованием озонидов с дальнейшим превращением последних в гидропероксиды (60%). Селективность окисления по этильной группе не превышает 34 %, основными продуктами реакции с сохраненной ароматической структурой являются метилфенилкарбинол (10% в точке экстремума при окислении этибензола), ацетофенон (34%). Исследовано влияние условий окисления и катализатора на селективность и состав продуктов окисления по боковой цепи. Показано, что селективность окисления по этильной группе увеличивается до 78,2 % в присутствии катализатора диацетата марганца. Рассмотрены схемы химических превращений, объясняющие полученные результаты.Вивчено реакцію етилбензолу з озоном в середовищі крижаної оцтової кислоти. Показано, що, при температурі 10 ºС етилбензол реагує з озоном переважно за бензеновим кільцем з утворенням озонідів та з подальшим перетворенням останніх в гідропероксиди (60%). Селективність окислення за етильною групою не перевищує 34%, основними продуктами реакції зі збереженою ароматичною структурою є метилфенілкарбінол (10% в точці екстремуму при окисленні етібензену), ацетофенон (34%). Досліджено вплив умов окислення і каталізатора на селективність і склад продуктів окислення за бічним ланцюгом. Показано, що селективність окислення за етильною групою збільшується до 78,2% у присутності каталізатора діацетату марганцю. Розглянуто схеми хімічних перетворень, що пояснюють отримані результатиThe oxidation of ethylbenzene by ozone in the environment of acetic acid was studied. It is shown, that at the temperature 10 ºС ethylbenzene react with ozone predominantly by the benzoic ring to forms ozonides wich further transform into hydroperoxides (60%). The selectivity oxidation of the ethyl group does not exceed 34%, with the main reaction products are stored aromatic structure methylphenylcarbinole (10 % at the extremum by oxidation of ethylbenzene), acetophenone (34%). The effect of oxidation conditions on the catalyst and the selectivity and the composition of the oxidation products of the side chain were investigated. It is shown that the selectivity of the ethyl group by oxidation is increased to 78.2% in the presence of manganese diacetate catalyst. The schemes of chemical transformations that explain the obtained results were considered

Single-mode cavities at frequencies of 172 and 178 MHz

In the report presented here the projects of two accelerating cavities with strong damping of higher modes (HOM) with special vacuum loads are presented. The designs of the cavities and loads are described. The design parameters of cavities, their spectra of higher modes and calculation results of the beam phase motion stability are given for the VEPP-2000 and NANOHANA Projects

RF system of the race-track microtron – recuperator for high power free electron laser

A brief description of the RF system of 100 MeV race-track microtron-recuperator being built in Novosibirsk for the Free Electron Laser project at Siberian center of Photochemistry research is presented. The frequency of RF system is 180.4 MHz. The RF system consists of 2 parts: the RF system of 2 MeV injector and the RF system of microtron. The injector RF system includes 3 RF cavities - one buncher cavity and two accelerating cavities. RF cavities are driven by a 2.5 kW amplifier and two high power single-tube 130 kW RF amplifiers respectively. The RF system of microtron includes 16 RF cavities operating at a gap voltage of 850kV each. Two 4-tubes power amplifiers supply the RF power of 600 kW each to the cavities via distribution feeders. In the high power amplifier stages the tetrodes GU-101A are used. The control system controls the amplitude and phase of RF voltage in the cavities and provides signals for synchronization of the electron gun. The results of the operation of the injector RF system and status of large RF system for the microtron are discussed

Results of measurements of the analyzing powers for polarized neutrons on C, CH <inf>2</inf> and Cu targets for momenta between 3 and 4.2 GeV/c

The analyzing powers for neutron charge exchange nA → pX reactions on nuclei have been measured on C, CH2 and Cu targets at incident neutron momenta 3.0 - 4.2 GeV/c by detecting one charged particle in forward direction. The polarized neutron measurements are the first of their kind. The experiment was performed using the Nuclotron accelerator in JINR Dubna, where polarized neutrons and protons were obtained from breakup of a polarized deuteron beam which has a maximum momentum of 13 GeV/c. The polarimeter ALPOM2 was used to obtain the analyzing power dependence on the transverse momentum of the final-state nucleon. These data have been used to estimate the figure of merit of a proposed experiment at Jefferson Laboratory to measure the recoiling neutron polarization in the quasi-elastic 2H(e, e'n) reaction, which yields information on the charge and magnetic elastic form factors of the neutron

Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub

The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)\u2014a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration

First experimental results obtained using the highpower free electron laser at the siberian center for photochemical research

The first lasing near the wavelength of 140 µm was achieved in April 2003 using a high-power free electron laser (FEL) constructed at the Siberian Center for Photochemical Research. In this paper we briefly describe the design of the FEL driven by an accelerator–recuperator. Characteristics of the electron beam and terahertz laser radiation, obtained in the first experiments, are also presented in the paper.У Сибірському центрі фотохімічних досліджень навесні 2003 року отримана генерація випромінювання з довжиною хвилі 140 мкм на потужному лазері на вільних електронах (ЛВЕ). У роботі коротко описана конструкція ЛВЕ на базі прискорювача рекуператора і представлені результати вимірювання деяких параметрів електронного пучка і терагерцового випромінювання.В Сибирском центре фотохимических исследований весной 2003 года получена генерация излучения с длиной волны 140 мкм на мощном лазере на свободных электронах (ЛСЭ). В работе кратко описана конструкция ЛСЭ на базе ускорителя рекуператора и представлены результаты измерения некоторых параметров электронного пучка и терагерцового излучения