Российская наука и мир (дайджест) - Июль 2005 г. (часть 2)
Навигация
Дайджест за другие годы
Июль
2005 г.
Российская наука и мир
(по материалам зарубежной электронной прессы)
январь февраль март апрель май июнь июль август сентябрь октябрь ноябрь декабрь

      Science News Daily / July 29, 2005
      Russian Titanium

    Оксид титана, который используют при производстве белил, бумаги, пластмасс и косметики, Россия покупает за рубежом, хотя своих месторождений у нас хватает. Проблема в том, что мы пока не можем наладить технологию извлечения титана из нашего сырья. Московские химики предлагают решение проблемы, которое они успешно апробировали в лаборатории.

The situation regarding titanium is paradoxical. On the one hand, titanium is found in abundance in the natural environment: in terms of natural occurrence in the earth's crust, the element is the third among all metals, directly following iron and aluminium. In industry, particularly in metallurgy it is used very rarely, about one hundred times less than aluminium. This happens in spite of the outstanding properties of titanium: it is lightweight, fast, heatproof and chemically stable. But it is too expensive as it is very difficult to extract it from minerals, and the raw materials for its production are extremely expensive.
It came to having to purchase titanium dioxide from abroad. It is used as a basis for titanium white, and the production of plastics, paper and even cosmetics. There are enough deposits in Russia; the problem is that Russia has not yet managed to establish the production of high-quality raw titanium.
This stumbling block will probably be removed soon with the help of the technology developed in the Baikov Institute of Metallurgy and Material Authority, Russian Academy of Sciences(IMET RAS), in the laboratory of Professor Reznichenko by G.B. Sadykhov, Doctor of Science (Engineering).
The rutile mineral is found in nature, it mainly consists of titanium dioxide. The researchers suggest that rutile should be educed from the so-called leucoxene petroliferous sandstones of the Yaregskoye deposit, which was previously considered absolutely hopeless for obtaining titanium dioxide.
The method of production is as follows: first, it is necessary to get rid of mineral oil the sandstone is imbued with. This mineral oil has been distilled off from Yaregsky sandstone by heating it without air. Then, the sandstone is heated once again; this changes its structure. The sandstone initially consists of over half ordinary sand, i.e. silicon dioxide - quartz. The latter is distributed irregularly: there are large agglomerates, and some agglomerates are as if ingrown in the rutile structure, they are the most difficult to get rid of. As a result of thermal treatment, the silicon dioxide structure changes, and it becomes much more active.
Strange as it may seem, rutile acquires ferromagnetic properties and starts to be pulled to the magnet. The researchers do not yet know for sure the reason for this happening, so far there is only a hypothesis that this is connected with minor iron admixtures. Finding out the reasons for this phenomenon is the subject of further research. However, the phenomenon has been persistently proved experimentally and it allows to separate rutile from quartz. As for silicon dioxide remaining with rutile in thin conglutination, it is much easier to remove - it is washed out of rutile by alkali solution.
As a result, the researchers manage (so far, only in a laboratory environment) to educe practically all titanium dioxide from ore, i.e., 90 to 95 percent of the initial content, and such synthetic rutile proves practically pure: it contains more than 90 percent of titanium dioxide and less than three percent of silicon dioxide. It is pure pleasure to get titanium white from such rutile.

© sciencenewsdaily.org

* * *

      RIA / 22/ 07/2005
      Des chercheurs russes surveillent l'activité solaire

    Запущенный 31 июля 2001 г. российско-украинский спутник КОРОНАС-Ф в течение вот уже почти  четырех лет ведет мониторинг солнечной активности и изучает солнечно-земные связи. Спутник представляет собой космическую обсерваторию, которая наблюдает Солнце во всем диапазоне электромагнитного спектра. Это позволяет исследовать строение нашего светила и его атмосферу, природу и механизмы различных проявлений солнечной активности. Например, происхождение и ускорение солнечного ветра, оказывающего непосредственное воздействие на Землю и околоземное космическое пространство; механизмы трансформации различных видов солнечной энергии внутрь магнитосферы и ионосферу Земли.

MOSCOU, 22 juillet (par Youri Zaïtsev, expert de l'Institut d'études spatiales relevant de l'Académie des sciences de Russie).  
Les chercheurs affirment que pendant les tempêtes magnétiques provoquées par les éruptions solaires on observe une montée d'adrénaline dans l'organisme humain, une modification du caractère de la circulation sanguine dans les vaisseaux, surtout capillaires, ainsi que des "poussees" de tension.
Ces phénomènes n'ont aucune incidence sur les jeunes pétant de santé. Chez les autres, cela pose problème. Auparavant on écoutait les bulletins météo dix fois par jour - plus souvent encore aujourd'hui - pour s'informer sur la situation géomagnétique.
Le satellite russo-ukrainien CORONAS-F lancé le 31 juillet 2001 surveille l'activité solaire et étudie les interactions entre le Soleil et la Terre. C'est un observatoire spatial dont la mission est de surveiller le Soleil et de l'étudier dans tout le registre du spectre électromagnétique. Il nous apprend beaucoup de choses sur la structure et l'atmosphère de notre astre, sur la nature et les mécanismes des phénomènes de l'activité solaire. Par exemple, l'origine et l'accélération du vent solaire, qui exerce un impact direct sur la Terre et l'espace circumterrestre: les mécanismes de transformation des différents types d'énergie solaire au sein de la magnétosphère et de l'ionosphère de la Terre.
Les aspects appliqués de ces observations consistent à comprendre l'influence de l'activité du Soleil sur l'atmosphère et la biosphère de la Terre, sur l'organisme de l'homme et les structures technologiques: lignes de transport d'électricité, télécommunications, canalisations, etc.
Les spécialistes dans les domaines les plus divers ont besoin des prévisions du temps spatial. Par exemple, ceux qui contrôlent l'état des communications radio ou sont chargés d'assurer la sécurité radioactive des cosmonautes. Privés pendant le vol spatial de la protection de l'atmosphère terrestre, pendant les éruptions solaires les plus actives, ils doivent se réfugier dans des abris spéciaux.
Ces éruptions sont dangereuses aussi pour les explorateurs automatiques de l'espace: leurs équipements électroniques ne résistent pas. En outre, sous l'effet de la radiation solaire accrue l'atmosphère terrestre se chauffe, se "dilate", sa densité dans les hautes altitudes augmente, ce qui a pour effet de freiner les satellites qui ont ainsi une durée de vie écourtée. C'est pour cette raison que les stations spatiales américaine Skylab et soviétique Saliout-7 se sont désintégrées. Cette dernière avait été mise en veilleuse et devait être réutilisée quelques années plus tard dans une version pilotée.
Pendant le fonctionnement de l'observatoire spatial CORONAS-F des archives exceptionnelles de représentations spectrales du Soleil et de sa couronne ont été constituées: près d'un million de clichés. Pour la première fois il a été possible de définir la teneur absolue de plusieurs éléments chimiques dans la couronne solaire. Les observations ont fourni de précieux renseignements sur les rayonnements X, ultraviolets, gamma et corpusculaires du Soleil et leur influence sur la magnétosphère, l'ionosphère et l'atmosphère de la Terre.
En vertu des tâches qui lui ont été assignées, le spectrophotomètre multicanaux installé à bord de l'observatoire peut être qualifié de "cardiographe" du Soleil. L'analyse de ses "cardiogrammes" a fourni des données sur la dynamique des couches internes du Soleil et les modifications de cette dynamique en fonction de l'activité solaire.
Un autre instrument scientifique unique en son genre: le spectromètre multicanaux des rayons X qui livre quotidiennement quelque 200 clichés hautement informatifs. Ces derniers ont permis d'enregistrer de nombreux phénomènes actifs sur le Soleil et d'en déceler la nature. Des données inédites ont également été obtenues sur la dynamique de la couronne solaire à distance de trois rayons solaires, un domaine qui jusqu'ici avait échappé à la surveillance.
Les données obtenues d'octobre à novembre 2003, une période marquée par la plus intense activité solaire de ces dernières décennies, présentent un intérêt exceptionnel. Plusieurs éruptions ont été d'une intensité record, elles se sont accompagnées de projections de plasma coronal à la vitesse de 2.000 kilomètres par seconde. Toutes les éruptions et pratiquement la quasi-totalité des rayonnements qui se génèrent pendant l'éruption ont été enregistrés par les instruments du laboratoire. Par ailleurs on a observé dans la couronne solaire toute une classe de phénomènes nouveaux qui ont été étudiés. Citons, entre autres, des formations plasmiques hautement dynamiques dont la température atteint 20 millions de degrés. Cette découverte permettra peut-être d'élucider ce problème de la physique du Soleil comme l'échauffement de la couronne solaire jusqu'à 1 million de degrés alors que la température à la surface de notre astre n'est que de 6.000 degrés environ.
L'observatoire solaire CORONAS-F et la sonde CORONAS-I, qui avait fonctionné en 1994-2001, sont des composantes du programme spatial russe CORONAS (Observations orbitales complexes circumterrestres de l'activité du Soleil). Sa prochaine étape devrait être la réalisation du projet Coronas-Foton portant sur l'étude du Soleil dans les bandes des rayons X et gamma.
D'une manière générale il faut dire qu'à part l'étude de notre astre, l'observation permanente du vent solaire sur son chemin entre le Soleil et la Terre est déterminante dans la prévision du temps spatial. Ici il faut un système de surveillance comportant plusieurs niveaux et il est en cours de conception par des chercheurs russes.
Dans l'ionosphère les observations se feront au moyen de micro-satellites Tchibis, créés à l'Institut d'études spatiales. Ils seront lancés depuis la Station spatiale internationale (ISS). À l'intérieur de la magnétosphère et dans les ceintures de radiation on utilisera des satellites Rezonans, qui seront lancés dans le cadre du Programme spatial fédéral. Leur mission essentielle consistera à étudier la dynamique fine de la ceinture de radiation, la corrélation entre les particules et les ondes à l'intérieur de la magnétosphère.
Aux niveaux supérieurs on trouvera un satellite (Intrebol-3), placé à un point de libration situé à environ un million et demi de kilomètres de la Terre. Grâce à l'équilibrage des forces d'attraction de la Terre et du Soleil, à cet endroit l'engin spatial pourra pendant une période prolongée rester "suspendu" près d'une ligne Soleil-Terre, le long de laquelle les nuages magnétiques nés sur le Soleil se deplacent et constituent un danger pour notre planète. Ce positionnement du satellite permettra de prévoir avec une grande fiabilité les tempêtes magnétiques une à deux heures avant leur naissance.

© 2005 "RIA Novosti"

* * *

      PhysOrg / 29 July 2005
      How Do We See What We See
    Способ объективно оценить информационную значимость изображения и, соответственно, качество видеоматериалов разработали исследователи Института когнитивной нейрологии Современной гуманитарной академии.

We look at a Gothic cathedral in a different way than we gaze at a standard apartment block, and when we scrutinize paintings, our gaze slides along differently than when we look at a datasheet with numerals to be memorized. And how are training materials - manuals, video films and websites - perceived, when as much information should be gained from a glance? How should they be made up to work most effectively? Specialists of the Institute of Cognitive Neurology (Modern University for the Humanities) have been researching these questions.
Recording eye movements, the researchers found the way to impartially assess informational significance of video materials. To this end, they applied the method of video oculography. The main advantage of the method is that it is noninvasive, i.e., does not require any intervention in the organism - neither application of electrodes or putting on contact lenses.
The image of an eye where a dark pupil is distinctly distiguished is recorded by an ordinary video camera. Displacement of the pupil's center along the eye image corresponds to displacement of a gaze along a visual stage. The system determines the pupil's coordinates with accuracy of about 0.5 degrees of arc and with high frequency, and represents the eye movement along the image on the computer monitor in the form of a track.
In the first experiment, 35 students of the Modern University for the Humanities at the age of 19 through 23 were tested. The students under investigation were offered to scrutinize various images on the computer monitor. The images included a copy of painting by Shishkin, a fragment of videocollection on psychology, a photo, text from a manual, a Web page, pictures with hidden image and others. The eyes' movement was registered during contemplation of images and fulfillment of some visual tasks with the help of video-oculographic system.
Quick movement of eyeballs - saccades - accompany sight of any image. They are needed to transfer look at a new object, since discerning of fine details of the object necessary for its perception requires its projection onto the central part of retina. This is explained by the fact that it is in the central part of retina that light-sensitive photoreceptors - cones - are placed with high density. The process of image scrutinizing consists of eye focusing on some objects and transition to other objects. This process is recorded in the course of experiment.
Having laid the eyeball movement tracks (obtained with the help of the program) upon images, the researchers have determined what parts of the image bear the most information to the looker. Obviously, the gaze is focused the longest on the most informationally significant objects. The method also shows at what rate the brain perceives and processes obtained visual information, and how quickly a person under investigation can embrace the entire image, switching from one object to another.
Applied to a website, such information indicates its quality without bias. If according to the designer's idea, the user should pay more attention to some objects, but in reality the user's look does not dwell on these objects, it means that the website does not work as it should. It is very important for educational video materials what strategy the user applies for data search. That accounts for success of learning the material. The method will undoubtedly be very useful when creating new video products and for expert judgement on available materials.
The method has one more use, which the researchers investigated in the second experiment. Its goal was to evaluate the eyes' movement in the course of mastering knowledge, for example, when memorizing foreign words from a sheet, which was suggested to 19 persons under investigation. To remember a word, it is necessary to hold up a glance on it. It can be assumed that efficiency of memorizing the word will depend on the time the glance is fixed on it. Subjects were asked to learn by heart as many Latin words as possible, for this purpose, a list of words with the Russian translation was shown to them for 5 minutes. Then followed testing in the course of which the persons were to insert in the table the words they had memorized.
The persons under testing remembered from 1 to 12 words, or 4.53 on the average. The analysis proved that the time of gaze focusing on the words the persons had memorized was positively longer than on those they had failed to remember. The researchers believe that the method is applicable for control of training process effectiveness.

© PhysOrg.com 2003-2004

* * *

      AlphaGalileo / 29 July 2005
      Climate Is Regulated By Water

    Около ста лет назад шведский химик и естествоиспытатель Сванте Аррениус высказал гипотезу о том, что температура воздуха у поверхности Земли повышается под влиянием парникового эффекта, создаваемого углекислым газом. С тех пор ученые, моделируя климат планеты, уделяют основное внимание именно СО2.
    Российские же географы убеждены, что основным регулятором климата Земли служит вода во всех трех состояниях: в виде водяного пара, гидросферы и облаков, льда и снега. Роль парниковых примесей, в том числе и углекислого газа, в сотни раз менее существенна.

About one hundred years ago, S. Arrhenius brought forward a hypothesis that the atmospheric temperature of at the surface of the Earth was increasing under the influence of the glasshouse effect created by carbonic acid gas. Since that time, the researchers, when simulating the planet climate, have mainly focused on O2 and it is water vapour that comprises the largest mass of all greenhouse gases. Thanks to water vapour and clouds, the average temperature at the surface of the planet is about 15 degrees C, instead of minus 58 degrees C (absolutely dry air would have this particular temperature).
Measuring air temperature at night in windless weather, in absence of low clouds, fogs or precipitations, the researchers have come to the conclusion that cooling down of the earth surface depends on water vapour concentration: the high the concentration is, the more warmth the Earth would preserve. In this case, water vapour plays the role of greenhouse gas in the atmosphere.
Other greenhouse admixtures - carbon oxide and dioxide, often called carbon monoxide and carbonic acid gas, sulfur dioxide and nitrogen dioxide, hydrogen chloride, ammonia and many others - also impact the air temperature, but their role in this process is much weaker. This is explained by the fact that water vapour density (absolute humidity) is by two to three times higher that that of other admixtures. And the quantity of radiation, including thermal radiation, absorbed by some admixture and the rise of temperature caused by it is proportionate to the concentration (density) of this admixture.
Cloud sheets play an important role in the thermal conditions of the Earth. According to space exploration data, in all continents of the Northern hemisphere, there is a connection between average monthly values of cloud quantity and surface air temperature. In the warm half of a year, this connection is tight enough, in the cold one - it is slightly weaker. The only exception to the rule is Europe in summer.
The amount of cloud, according to the same data, is increasing with each decade: since 1971 through 1990 it increased by 2 percent in the Northern hemisphere, by 4 percent - in the southern hemisphere, and by 3 percent - above the Earth on the whole. Based on this data, the researchers claim that carbonic acid gas and other admixtures, to which main attention was paid in the 20th century when simulating the climate, do not play a significant role in changing thermal conditions of the Earth.
The Moscow geographers believe that climatologists have no grounds at all to talk about such change, as the main part of the planet, including oceans and deserts, is not embraced by meteorological watch. It should also be taken into account that all evaluations of global temperature changes are obtained through observations in inhabited localities, where it is always more damply and cloudy, and consequently, hotter than in the uninhabited locations. Terrestrial climate specialists should particularly focus their effort on the problem of interaction between fluxes of radiation and humidity and cloudiness fields.

© AlphaGalileo Foundation 2003

* * *

      Innovations report / 04.07.2005
      Useful Bacteria Need Protection

    Новосибирские исследователи разрабатывают новые формы лекарств от дисбактериоза и прочих кишечных расстройств. В таких случаях пациентам обычно прописывают эубиотики - препараты, содержащие бактерии, необходимые для пищеварения. Но в желудке они разрушаются, что приводит к снижению их эффективности. Защитить бактериальные составляющие препаратов можно, поместив их в капсулы или на специальный носитель-сорбент (иммобилизованная форма). Новосибирские ученые создают и испытывают иммобилизованные эубиотики. Клетки полезных бактерий наносят на пористый микроноситель - порошок оксида алюминия. С поверхностью микроносителя белки клеточной стенки бактерий образуют хелатные комплексы, которые проходят через желудок без потерь и распадаются в нижних отделах тонкого кишечника.

New forms of drugs for dysbacteriosis and other gastrointestinal disturbances are being developed by the Novosibirsk researchers with support of the International Science and Technology Center (ISTC).
A lot of Russians suffer from malfunction of gastrointestinal tract. The frequent reason for that is dysbacteriosis - disturbances of normal intestinal flora. To fight dysbacteriosis, physicians prescribe eubiotic drugs to patients, which contain bacteria necessary for digestion, for example, bifidumbacterin, lactobacterin, colibacterin, bificol, etc. The drugs are good, but upon intake they are destroyed in the stomach, due to that their efficiency reduces. To increase efficiency of eubiotics, they should be protected in some way.
This problem is being solved by the researchers of the State Research Center for Virology and Biotechnology "Vector" ("Vector-BiAlgam" close corporation (Koltsovo, Novosibirsk Region)) with support of the International Science and Technology Center (ISTC). Bacteria making part of the drugs need protection, and there are two main methods to defend them. The bacteria are either placed into a capsule - this is a capsulated form of drug, or they are placed on a special carrier - sorbent - this is an immobilized form.
The Novosibirsk researchers are developing and testing immobilized eubiotics. In this medication, cells of useful bacteria are placed on porous microcarrier SUMS-1 - aluminium oxide powder, the size of microparticles varying from 40 to 100 mkm, the surface of microparticles being covered by carbon (which is used in medicine as enterosorbent). Adsorption occurs on the carrier owing to both physical and chemical mechanisms. Proteins of the cellular wall of bacteria form chelates with the SUMS-1 surface, where magnesium serves as a complexing agent (chelation). In this case, active groups of bacteria's proteins and lipoproteids turn out to be protected from the stomach's aggressive acid medium. In the meantime, unprotected bifido- and lactobacteria lose more than 90 percent of their activity in the stomach, the immobilized ones go lossless through the stomach.
Chelates are known for their stability being dependent on the medium. As the stomach has acid medium, bacteria remains in it bound with sorbent. When the drug gets into lower parts of thin bowels, the chelate disintegrates due to increased. This is what is needed, because it is particularly in the thin bowels and than in the thick bowels that bifido- and lactobacteria get released from the carrier and start working. The released sorbent surface takes away toxins and metabolic products. SUMS-1 is a very efficient enterosorbent: it does not sorb small molecules - acids, carbohydrates, trace elements and it does not sorb large mass proteins either - transport proteins and enzymes. That is why the water-salt balance is not broken and bowel' enzymatic activity does not decrease. Along with that, SUMS-1 actively binds proteins of medium mass, where toxins and products of uncomplete metabolism belong to. They are brought out of the organism together with the sorbent.
The Novosibirsk researchers have created complex eubiotic based on the SUMS-1sorbent, which includes consortium of several species of the most active cultures of bifido- and lactobacteria. These bacteria suppress reproduction of pathogenic, saprogenous and gas-producing microflora, they participate in peptic processes and synthesis of vitamins, in metabolism of trace elements and biologically active substances. On top of that, bifido- and lactobacteria act as immunostimulants.
New drugs underwent investigation at all levels. Testing them on laboratory animals, the researchers have made sure that they are non-toxic, do not cause side effects and at the same time destroy harmful intestinal flora and increase vital capacity of the organism. While clinical trials of the complex immobilized eubiotic are being prepared, the Novosibirsk State Medical Academy (based on the clinic) has already carried out clinical trials of its analogue called "Ecoflor", which belongs to the category of bioactive nutritional supplements. 70 patients who were taking "Ecoflor" within two weeks have improved digestion and general habitus, and the gut organisms have become normal. The complex eubiotic production is still limited to pilot batches, and its analogue "Ecoflor" is already produced as a bioactive nutritional supplement.
And finally, it should be pointed out where new eubiotic drugs will be applied. They will be used not only for dysbacteriosis but also for toxin poisoning, enteric infection, pancreatitis, gastritis, ulcer and other chronic ailments, allergy, radiolesion and even tuberculosis and oncology treatment.

* * *

Начало дайджеста за ИЮЛЬ 2005 года (часть 1)
январь февраль март апрель май июнь июль август сентябрь октябрь ноябрь декабрь

предыдущий месяц
1998-2005
следующий месяц
[О библиотеке | Академгородок | Новости | Выставки | Ресурсы | Библиография | Партнеры | ИнфоЛоция | Поиск | English]
  Пожелания и письма: www@prometeus.nsc.ru
© 1997-2018 Отделение ГПНТБ СО РАН (Новосибирск)
Статистика доступов: архив | текущая статистика
 

Документ изменен: Thu Apr 5 16:45:24 2018. Размер: 33,752 bytes.
Посещение N 2770 с 09.11.2005