83 research outputs found

    Human Associations Help to Detect Conventionalized Multiword Expressions

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    In this paper we show that if we want to obtain human evidence about conventionalization of some phrases, we should ask native speakers about associations they have to a given phrase and its component words. We have shown that if component words of a phrase have each other as frequent associations, then this phrase can be considered as conventionalized. Another type of conventionalized phrases can be revealed using two factors: low entropy of phrase associations and low intersection of component word and phrase associations. The association experiments were performed for the Russian language

    Intrapersonal conflict as a factor of adaptation of students to conditions of teaching at universities

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    The article reviews the current state of studying the problem of interpersonal conflict as a factor in adaptation, characterized by consideration of the relationship of these categories on two levels: intrapersonal conflict is studied as a driving force, a source of self-in the process of adaptation and as a leading indicator of complications adaptation. It is determined that the impact of interpersonal conflict in the course of adaptation depends on self-identity in a complex interaction of external (socially determined) and internal (individual personality) factors. It is indicated that psychological content intrapersonal conflict experiences have a high degree of individual differentiation and thus determine the uniqueness of perception and interpretation of a specific person. An indicator of the transition from one level to another intrapersonal difficulties acts vulnerability to conflict self-relations context of inner experience. The nature of the adaptation of the student is determined by the internal model and solve interpersonal experiences complications, which are formed in the mind and form the basis of individual experience

    Changes in composition and structure of nitrogenous bases of resin components of heavy oil from the Nurlatskoe oilfield in the course of thermal decomposition

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    The relevance. The need to obtain information on heat treatment effect on composition and structure of nitrogenous bases of resin components of heavy oil from the Nurlatskoe field (Republic of Tatarstan) to solve the problems associated with their negative impact on oil refining. The aim. To characterize the composition of nitrogenous organic bases, isolated from the resins of bituminous oil of the Nurlatskoe field, and the products of their thermal cracking. Methods. Complex formation, extraction, liquid adsorption chromatography, potentiometric titration, 1H NMR spectroscopy, structural group analysis, combined gas chromatography-mass spectrometry. Results. Based on a comparative study of the composition and structure of nitrogenous bases of the initial and thermally treated resins of the bituminous oil from the Nurlatskoe field, the authors found out that they both contain high- and low-molecular nitrogenous bases with predominance of high-molecular compounds precipitated by hydrogen chloride. As a result of thermal exposure, the number of such bases increases due to an increase in the proportion of compounds with shorter alkyl substituents in their composition. The method of structural group analysis was used to show that the main directions of thermal transformations of high- and low-molecular bases of resins in Nurlatskoe oil are destruction of alkyl substituents and cyclization of shortened alkyl chains with formation of naphthenic rings. Among the lowest molecular weight bases of the initial resins and thermolysate the authors have identified alkyl-substituted quinolines, benzoquinolines, azapyrenes, thiophenoquinolines, and benzothiophenoquinolines with similar molecular weight distributions. During the thermolysis of resins, the relative content of low molecular weight homologues in the identified nitrogenous bases increases. The share of structures with reduced chromatographic mobility caused by a decrease in the degree of spatial screening of a nitrogen atom increases among similar homologues

    Nitrogen-containing compounds of Kazakhstan petroleum vacuum gas oil

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    Relevance. The need to accumulate data on nitrogen-containing compounds of heavy fractions, the share of which in secondary oil refining is steadily increasing every year. With the weight of raw materials the amount of sulfur-, nitrogen- and oxygen-containing components in it increases. The high content of heteroatomic compounds has a negative impact on catalytic processing, the quality and performance characteristics of the products obtained, and the environment. One of the widespread processes for upgrading crude oil, in particular, vacuum gas oil, is hydrotreating. However, during the catalytic hydrodesulfurization of heavy distillates the reactions of hydrogenolysis of organic sulfur compounds are inhibited in the presence of nitrogen-containing compounds. At the same time, the degree of hydrodenitrogenation of heavy oil fractions is relatively low. It is known that petroleum nitrogen-containing compounds are divided into nitrogenous bases titrated with acid solutions and nonbasic nitrogen compounds. Nitrogenous bases are represented mainly by alkylbenzo- and alkylnaphthenobenzo derivatives of pyridine. Nonbasic compounds may include benzologs of pyrrole and amides. Determining the composition of nitrogen-containing compounds in vacuum gas oil and studying their transformations during hydrotreatment is an important and actual problem. Aim. Comparative study of high- and low-molecular nitrogenous bases and nonbasic nitrogen-containing compounds of vacuum gas oil of Kazakhstan oil before and after hydrotreating. Objects. Samples taken before and after the catalytic hydrotreatment of vacuum gas oil from Kazakhstan oil. Methods. Hydrotreatment, elemental analysis, potentiometric titration, benzene cryoscopy, IR and 1H NMR spectroscopy, structural group analysis. Results. The paper introduces a comparative characteristic of the composition and structure of high and low molecular weight nitrogenous bases from the original and hydrotreated vacuum gas oil. Under the conditions of hydrotreatment, the total removal of nitrogen was 6.56 wt %, and the content of Nbas. decreased by 36%. At the same time, nitrogenous bases in the hydrotreated product are characterized by low molecular weights. Using IR spectroscopy, similar structural fragments were identified in the nitrogen compounds of the original and hydrotreated vacuum gas oil: pyridine rings (1573–1574 cm–1), carboxylic (3209–3225 and 1701–1709 cm–1) and sulfoxide (1032–1033 cm–1) groups. Among the nitrogen-containing compounds of the original vacuum gas oil, amides (1647–1648 cm–1) were identified, which are absent in the composition of nitrogen-containing compounds of the hydrotreated vacuum gas oil. Hydrocarbon skeletons of molecules include aromatic (1599–1602 cm–1) and aliphatic fragments (2860–2960 and 1454–1460, 1377, 723–727 cm–1). In accordance with the results of the structural group analysis, the averaged molecules of high and low molecular weight nitrogenous bases of the original and hydrotreated vacuum gas oil are represented by naphthenoaromatic structures with different alkyl framing. The differences observed between the values of individual structural parameters of the nitrogenous bases average molecules of the original and hydrotreated vacuum gas oil may indicate the compounds transformations under study during hydrotreatment

    Thermal Transformations of Organic Nitrogen Bases in Resin Components of Oils of Various Types

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    Изучены состав и структура азоторганических оснований смол малосмолистой и высокосмолистых нефтей до и после термического воздействия (450 °С, 30 мин, инертная среда). Установлено, что большую часть оснований во всех исследуемых образцах смол составляют высокомолекулярные соединения, однако их доля в термолизованных смолах существенно ниже. Термопреобразованные основания характеризуются меньшими значениями средних молекулярных масс, меньшим числом и меньшими размерами структурных блоков, входящих в состав их средних молекул. Уменьшение общих размеров структурных блоков происходит в основном за счет снижения числа насыщенных циклов в нафтеноароматической системе и количества углеродных атомов в алкильном обрамлении. По данным ГХ-МС, основания всех исследуемых смол представлены сходными наборами алкилпроизводных хинолина, бензохинолина, дибензохинолина и азапирена. В составе оснований смол высокосернистых нефтей в заметном количестве присутствуют алкилпроизводные тиофенохинолина и бензотиофенохинолина. Во всех случаях максимум в распределении идентифицированных соединений приходится на алкилбензохинолины. Особенностью азоторганических оснований термопреобразованных смол является повышенное содержание алкилхинолинов и алкилтиофенохинолинов, а также более высокая доля в их составе структур с меньшим числом атомов углерода в алкильных заместителях. Таким образом, основные направления термического преобразования азоторганических оснований смол не зависят от химической природы нефтиThe composition and the structure of organic nitrogen bases of resins of low- and high-resin oils are studied before and after thermal exposure (450 °C, 30 minutes, inert medium). It is found that most of the bases in all samples of resins under study are high-molecular compounds, but their content in thermolized resins is significantly lower. Thermally transformed bases are characterized by lower values of average molecular weights, minority and smaller sizes of structural blocks constituting their mean molecules. A decrease in the overall size of the structural blocks is mainly due to a decrease in the number of saturated cycles in the naphtheno-aromatic system and carbon atoms in alkyl substituents. According to GC-MS data, the bases of all the resins under study are represented by the same sets of alkyl derivatives of quinoline, benzoquinoline, dibenzoquinoline, and azapirene. Alkyl derivatives of thiophenoquinoline and benzothiophenoquinoline are present in the composition of bases of highsulfur oil resins in significant amounts. In all cases, the maximum in the distribution of identified compounds falls to alkyl benzoquinolines. The special feature of organic nitrogen bases of thermally transformed resins is a high content in alkylquinolines and alkylthiophenoquinolines, as well as a higher percentage of structures with a lower number of carbon atoms in alkyl substituents. Thus, the chemical nature of oils is not responsible for main patterns of thermal transformation of organic nitrogen bases in oil resin

    Transient non-collinear magnetic state for all-optical magnetization switching

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    Resonant absorption of a photon by bound electrons in a solid can promote an electron to another orbital state or transfer it to a neighboring atomic site. Such a transition in a magnetically ordered material could affect the magnetic order. While this process is an obvious road map for optical control of magnetization, experimental demonstration of such a process remains challenging. Exciting a significant fraction of magnetic ions requires a very intense incoming light beam, as orbital resonances are often weak compared to above-band-gap excitations. In the latter case, a sizeable reduction of the magnetization occurs as the absorbed energy increases the spin temperature, masking the non-thermal optical effects. Here, using ultrafast x-ray spectroscopy, we were able to resolve changes in the magnetization state induced by resonant absorption of infrared photons in Co-doped yttrium iron garnet, with negligible thermal effects. We found that the optical excitation of the Co ions affects the two distinct magnetic Fe sublattices differently, resulting in a transient non-collinear magnetic state. The present results indicate that the all-optical magnetization switching most likely occurs due to the creation of a transient, non-collinear magnetic state followed by coherent spin rotations of the Fe moments

    Electron population dynamics in resonant non-linear x-ray absorption in nickel at a free-electron laser

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    Free-electron lasers provide bright, ultrashort, and monochromatic x-ray pulses, enabling novel spectroscopic measurements not only with femtosecond temporal resolution: The high fluence of their x-ray pulses can also easily enter the regime of the non-linear x-ray–matter interaction. Entering this regime necessitates a rigorous analysis and reliable prediction of the relevant non-linear processes for future experiment designs. Here, we show non-linear changes in the L3-edge absorption of metallic nickel thin films, measured with fluences up to 60 J/cm2. We present a simple but predictive rate model that quantitatively describes spectral changes based on the evolution of electronic populations within the pulse duration. Despite its simplicity, the model reaches good agreement with experimental results over more than three orders of magnitude in fluence, while providing a straightforward understanding of the interplay of physical processes driving the non-linear changes. Our findings provide important insights for the design and evaluation of future high-fluence free-electron laser experiments and contribute to the understanding of non-linear electron dynamics in x-ray absorption processes in solids at the femtosecond timescale
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