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10Решетневскце чтения
Т. Кобский
Чешский технический университет, Чешская Республика, Прага
МОДЕЛИРОВАНИЕ ХИМИЧЕСКОЙ УСТОЙЧИВОСТИ УАМ-069 И ОДНОГО ИЗ ПРОДУКТОВ ЕГО РАСПАДА
Для развития процесса ядерного гидрометаллургического разделения необходимо продемонстрировать стабильность систем извлечения. В этом процессе используется соединение m-xylylene-bis-diglycolamide (соединение 1), но его неустойчивость является нежелательной характеристикой. Известно, что один из продуктов деструкции (2) значительно более устойчив и имеет сопоставимые свойства извлечения. Моделирование химической стабильности показало значительно менее ограниченную плотность HOMO для 2, что соответствует более низкому предпочтению кислородного атома эфира, расположенному в слабой позиции.
© Koubsky Т., 2011
УДК 53
I. Kraus
Czech Technical University, Czech Republic, Prague
SOLID STATE PHYSICS AT THE CZECH TECHNICAL UNIVERSITY IN PRAGUE
The contribution contains a brief description of the solid state physics research at the Faculty of Nuclear Sciences and Physical Engineering (FNSPE) of the Czech Technical Unversity in Prague.
There is no doubt that among all the fields of physics, solid state physics is dominant as far as the number of scientists is concerned for whom it has become their career, as well as the institutions which conduct experiments with solid state substances, search for theoretical explanations for their observed behaviour, and express hypotheses for their new properties. Solids are also unequalled in the number of journals accepting contributions in this field, the number of publications, and their use in real life.
Keeping in view the discoveries of the 20th century that have changed our lives from the very fundamentals (splitting of uranium, semiconductors, and the laser), two of them can be attributed to solid state physicists. The first discovery was made by Shockley-Bardeen-Brattain, a trinity of American physicists, towards the end of the 40's. They appeared on the Nobel Prize Winners' list in physics on December 10th, 1956, for investigations into semiconductors and the discovery of the transistor phenomenon. The second greatest discovery of the recent time is the laser (Light Amplification by Stimulated Emission of Radiation). Its parents are Charles Hard Townes, an American, and Nikolay Gennadievich Basov and Alexander Mikhailovich Prochorov, two Russians, Nobel laureates for 1964.
Czech Technical University in Prague included solid state physics into its programmes as early as autumn 1960. In the beginning, training was provided by three full-time members of staff of the Solid State Physics Section of the then Faculty of Technical and Nuclear Physics, and several dedicated part-timers; later a proper
department was founded, since 1967 known as the Department of Solid State Engineering. Its scientific activities was then defined by both the objektive factors (i. e., state of the art of the field), and the scientists leading the team of academic and technical staff. In the beginning, the research issues covered mainly the theory of solids, theory of magnetism, and technology of magnetic substances; later the attention shifted to research into semiconductor technology, semiconductor detectors, X-ray and neutron diffraction, optical properties of solids, nanotechnology, surface physics, polymer physics and materials simulations.
To those interested in studying physical engineering, the Faculty offers both courses of the „non-engineering" type (i. e. calculus and analysis, algebra, numerical mathematics and statistics, quantum mechanics, nuclear physics, crystallography, theory of solids, physics of metals and dielectrics), and the „engineering" type, e. g. applications of computer technology, superconductivity, applications of semiconductor electronics, semiconductor technology, semiconductor measurements methods of solids, experimental methods of X-ray and neutron diffraction, and others.
The first scientific achievement of note that brought the Department to the attention of peers was the theory of spontaneous magnetisation of thin ferromagnetic films and also the preparationn of layers by vakuum evaporation for ferromagnetic elements of the iron group and the lanthanides. Close cooperation with the Institute of Magnetic Substances in Jena also helped to develop the technology and fundamental magnetostatic masurements
Наноматериалы и нанотехнологии в аэрокосмической отрасли
of new magnetic materials based on compounds of uranium.
Structural changes at the Faculty in 1967 brought about changes at the Department, resulting in extending the team engaged in X-ray diffraction and establishing a new semiconductor team concentrated on the technology of semiconductor elements and development of measuring techniques. In the years that followed, an original approach had been elaborated for observing the dotation profile of epitaxial and diffusion layers of silicone by the resistence technique, Hall effect measurements were designed and performed by applying changing magnetic field and voltage of various frequency, and the industry was able to introduce homogeneous alloying of silicone by thermal neutrons.
Of unique importance not only within the Faculty, but nationwide, is the Department's section focusing its attention on the use of diffraction of thermal neutrons in solid state physics and in material science research. The Neutron Laboratory, founded in 1967, is now equipped with unique instruments for diffraction analysis of monocrystalline as well as polycrystalline substances. The research focuses on texture determination, placement of light atoms in the structure, study of magnetic arrangements, and phase transitions.
The Department's longest tradition - from 1960 until today - has been connected with X-ray diffraction residual stress analysis. This research is a good example of how physical engineers are trained at FNSPE: perfekt understanding of the theory of physical processes, preparation and mastering of the experiment verifying the validity of theoretical conclusions, and cooperation in introducing laboratory research results into industry.
No wonder that until not long ago, the industry had been reluctant to accept the conclusions of the diffraction methods. While with the destructive methods the changes due to stress can be observed directly - they can be seen -X-ray tensiometry is based on trusting the laws of diffraction and interference of invisible radiation.
However, recently there has been a decline in the number of sceptics. Most probably, the decline has occured because the list of products requiring a tensiometric expert's opinion from an X-ray laboratory, a condition for selling them to customers from developed countries, is getting longer and longer, year by year. Or, maybe, technologists no longer rely on their eyes in searching the truth. „What is important cannot be seen by eyes", sayes Antoine de Saint-Exupéry in his book The Little Prince. The same can be expressed in an unpoetic way. According to the experience of countries of high technology, the knowledge of residual stresses is first of all made effective use of where there is no mistrust between research and production, and where information flows both ways.
X-ray Laboratory at the FNSP CTU is engaged both in teaching and research, and so students can study from two monographs on X-ray stress analysis written by the staff [1; 2]; in the world scientific community sources on similar topics can be counted on the fingers of the hand. This was also why the X-ray people from CTU were invited to join the team of authors to write a book on industrial applications of X-ray diffraction. Forty-four institutions from 14 countries got a chance to inform the world scientists and engineers what question can be put to X-rays. Physical engineers from the CTU were asked by the American editors to contribute a chapter on residual stress and stress gradients. The book was published in New York in the year 2000; it has over 1000 pages and FNSPE CTU is thus listed among the chosen world X-ray laboratories.
References
1. Kraus I., Trofimov V. V. Rentgenova tenzometrie. Prague : Academia, 1988.
2. Kraus I., Ganev N. Residual Stress and Stress Gradients. In: Industrial Applications of X-ray Diffraction. New York - Basel : Marcel Dekker, 2000.
И. Краус
Чешский технический университет, Чешская Республика, Прага
ФИЗИКА ТВЕРДОГО ТЕЛА В ЧЕШСКОМ УНИВЕРСИТЕТЕ В ПРАГЕ
Описаны исследования в области физики твердого тела, которые проводятся на факультете ядерной физики и физической техники (FNSPE) Чешского Технического университета в Праге.
© Kraus I., 2011
