Навигация
Дайджест за другие годы
Февраль
2006 г.
Российская наука и мир
(по материалам зарубежной электронной прессы)
январь февраль март апрель май июнь июль август сентябрь октябрь ноябрь декабрь

    innovations report - Bad Homburg, Germany / 23.01.2006
    Model For Arctic Zone
    Северные приполярные области обычно труднодоступны для непосредственного изучения, поэтому главным методом их исследования становится наблюдение на расстоянии посредством микроволнового и радарного зондирования и радиометрии. Разработкой новых методов и программно-аппаратных средств микроволновой радиометрии для мониторинга биогеохимических циклов приполярных территорий Сибири занимаются российские (Институт физики им. Л.В.Киренского СО РАН) и американские (Университет им. Анны Арбор, Мичиган) исследователи при поддержке Американского фонда гражданских исследований и развития (CRDF) и Федерального агентства по науке и инновациям Российской Федерации (Роснаука).

The development of a new dielectric model of tundra and forest-tundra for remote probing from space is being performed by Russian researchers from the L.V. Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences (Krasnoyarsk) jointly with the US colleagues from Michigan. The researches are sponsored by the U.S. Civilian Research & Development Foundation (CRDF) and the Federal Agency for Science and Innovation (Rosnauka). The new model will make basis for more accurate and trustworthy climatic forecasts.
Northern sub-polar areas, these being not only boundless lands of Siberia, but also vast territories of Canada and Alaska, are going through hard times. Consequences of global warming make the strongest impact on them. The temperature is rising, ice cover is decreasing, permafrost is thawing, flora is changing, arctic birds and animals are migrating. The majority of sub-polar areas is remote and difficult of access. Therefore remote probing from space is becoming now the main method of their investigation. This includes microwave and radar sounding and radiometry.
Radiosounding data can provide information about streams of warm and moisture between the surface of the earth and atmosphere taking into account soil thawing and freezing. Researchers state that trustworthiness of global climate models can be increased if they take into account changes in moisture and heat streams. Reliability of moisture and heat streams determination by radiosounding depends in principle on physical reliability of the so-called soil and flora dielectric models. Russian researchers have set about to develop this particular model for tundra and forest-tundra.
The soil, per se, represents a dielectric, the properties of which may be characterized by permittivity. The latter mainly depends on water content in the soil. When soil moisture freezes and then thaws out, the soil permittivity changes abruptly. Magnitude of such sudden changes depends significantly on the content of the so-called bound soil moisture not frozen at temperatures below freezing. These fluctuations are reflected in sudden changes of brightness temperature and radar signals at microwave probing of soil. Brightness temperature – is one of important characteristics of thermal balance of the surface. It is equal to the temperature of absolute black body, which would create irradiation of the same strength in the investigated frequency band. As strength of microwave irradiation is proportionate to the black body temperature, introduction of the brightness temperature notion noticeably simplifies radiometry methods and data interpretation.
Several years ago, Siberian researchers suggested the spectroscopic dielectric model of moist soils. It took into account the mineral composition, organic matter content, volumetric moisture, temperature and wave frequency. From their part, the US colleagues developed and justified the model, binding brightness temperature with moisture and heat streams.
Now the researchers set a task to combine these two models. A new improved model for remote probing may be checked in operation by comparing it to the longstanding surface observations data. And then, the researchers believe, it will be possible to apply the model to various soils and flora found in subpolar Arctic, thus noticeably increasing the quality of climatic forecasts.
"These results are particularly important for the community of researchers who deal with remote probing in view of the scheduled space projects HYDROS and SMOS," emphasized Valery Mironov (L.V. Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences), Corresponding Member, responsible for the Russian-US project.

* * *
    AlphaGalileo / 25 January 2006
    Air: radical purification
    Обеспечить глубокую очистку воздуха можно в недрах коллекторов-катализаторов, синтезированных российскими учеными. Такие катализаторы позволят превратить ядовитые примеси, отравляющие воздух, в малоопасные, либо совсем безопасные соединения. Поддерживает исследования ученых Международный научно-технический центр.

Scientists from the University of Nizhny Novgorod believe that ozone, an original synthetic porous material called KhIPEK and a special catalyst will protect us from the harmful effect of potentially hazardous matter – chemical and biological substances. The research by chemists and biochemists is supported by the International Science and Technology Centre, which has placed information on this promising development on its website http://tech-db.istc.ru.
Chemically and biologically active substances are irreplaceable in many chemical reactions, including in the activity of large-scale enterprises in various spheres of production and everyday life. However, to counter their advantages, their high activity can lead to dangerous situations, and therefore the environment and humans have to be protected from such incidents. And specialists from the RFNC the All-Russia Research Institute of Experimental Physics and their colleagues from the Lobachevsky University of Nizhny Novgorod know how to do this.
The method proposed by the scientists unites the advantages of several traditional chemical approaches to air purification. It is the oxidation of toxic substances with ozone on the surface of porous ceramic materials that possess catalytic properties. As a result, state the authors of the development, the toxicants will become far less harmful or they will lose their toxic force completely. The guarantee of success lies not only in the catalysts, but also in special sorbents which the group of chemists, led by Academician of the RAES Professor Yuri Alexandrov, have been developing now for several years.
The problem is that the "ozonation" method, despite clear advantages over other means of purification, has still not received widespread application. The reason is the very same; the high toxicity of ozone. What is needed is extremely high production standards and strict control over all chemical processes that involve it – this is the strongest of oxidants. It is another matter if it proves successful to strictly dose it or, even better, to restrict it spatially. And this is what the chemists from Nizhny Novgorod have succeeded in achieving – with this sorbent, the foamed ceramic KhIPEK.
Strictly speaking, the scientists have not only devised and patented this material; they have also learnt how to produce it, although to date they have preferred not to disclose its composition. To date it is the other qualities of this foamed ceramic that have been applied; it is used as a thermal insulation and fireproof construction material. However, this is also an excellent sorbent, both for ozone and for chemical and biological compounds. And if the sorbent surface is treated with an ultra-thin, multi-layer polymer film that is able to capture biological substances, and if it is impregnated with a catalyst to ease the interaction between these substances, then the job, we can say, will be done. It will be sufficient to pass air through a filter in the form of a ceramic sponge with a pre-applied catalyst layer, and saturated with ozone and toxic substances will completely or to a significant extent will lose their toxicity! And neither the environment nor humankind will suffer from potentially or actually toxic substances.
The research is not yet complete. However, the group has accumulated enormous experience in deep oxidative degradation or, put simply, the breakdown of various organic, metalloorganic and biological compounds by a method of ozonolysis on solid surfaces. They are also able to turn the results of theoretic surveys into a practical application. The KhIPEK they have developed, presented at the Techno Pia 99 – Intex Osaka won the acknowledgement of the Japanese. Thus, there is no doubt of the ability of the scientists or the commercial potential of the project. We wish the authors success and financial support, and this is because we are all winners in this situation.

© AlphaGalileo Foundation 2003

* * *
    Newswise (press release) – USA / Fri 27-Jan-2006
    Sonofusion Experiment Produces Results Without External Neutron Source
    Группа исследователей из Политехнического института Ренселера (Rensselaer Polytechnic Institute), университета Пурду (Purdue University) и Российской академии наук использовала звуковые волны, чтобы осуществить ядерный синтез без применения внешнего нейтронного источника. Речь идёт о "соносинтезе" - в смеси ацетона и бензола звуковые волны генерируют пузырьки газа, в которых на короткое время достигаются огромные температуры, а при разрушении пузырьков происходит ядерный синтез. Результаты были опубликованы в Physical Review Letters.

A team of researchers from Rensselaer Polytechnic Institute, Purdue University, and the Russian Academy of Sciences has used sound waves to induce nuclear fusion without the need for an external neutron source, according to a paper in the Jan. 27 issue of Physical Review Letters. The results address one of the most prominent questions raised after publication of the team's earlier results in 2004, suggesting that "sonofusion" may be a viable approach to producing neutrons for a variety of applications.
By bombarding a special mixture of acetone and benzene with oscillating sound waves, the researchers caused bubbles in the mixture to expand and then violently collapse. This technique, which has been dubbed "sonofusion", produces a shock wave that has the potential to fuse nuclei together, according to the team.
The telltale sign that fusion has occurred is the production of neutrons. Earlier experiments were criticized because the researchers used an external neutron source to produce the bubbles, and some have suggested that the neutrons detected as evidence of fusion might have been left over from this external source.
"To address the concern about the use of an external neutron source, we found a different way to run the experiment," says Richard T. Lahey Jr., the Edward E. Hood Professor of Engineering at Rensselaer and coauthor of the paper. "The main difference here is that we are not using an external neutron source to kick the whole thing off."
In the new setup, the researchers dissolved natural uranium in the solution, which produces bubbles through radioactive decay. "This completely obviates the need to use an external neutron source, resolving any lingering confusion associated with the possible influence of external neutrons," says Robert Block, professor emeritus of nuclear engineering at Rensselaer and also an author of the paper.
The experiment was specifically designed to address a fundamental research question, not to make a device that would be capable of producing energy, Block says. At this stage the new device uses much more energy than it releases, but it could prove to be an inexpensive and portable source of neutrons for sensing and imaging applications.
To verify the presence of fusion, the researchers used three independent neutron detectors and one gamma ray detector. All four detectors produced the same results: a statistically significant increase in the amount of nuclear emissions due to sonofusion when compared to background levels.
As a cross-check, the experiments were repeated with the detectors at twice the original distance from the device, where the amount of neutrons decreased by a factor of about four. These results are in keeping with what would be predicted by the "inverse square law", which provides further evidence that fusion neutrons were in fact produced inside the device, according to the researchers.
The sonofusion debate began in 2002 when the team published a paper in Science indicating that they had detected neutron emissions from the implosion of cavitation bubbles of deuterated-acetone vapor. These data were questioned because it was suggested that the researchers used inadequate instrumentation, so the team replicated the experiment with an upgraded instrumentation system that allowed data acquisition over a much longer time. This led to a 2004 paper published in Physical Review E, which was subsequently criticized because the researchers still used an external neutron source to produce the bubbles, leading to the current paper in Physical Review Letters.
The latest experiment was conducted at Purdue University. At Rensselaer and in Russia, Lahey and Robert I. Nigmatulin performed the theoretical analysis of the bubble dynamics and predicted the shock-induced pressures, temperatures, and densities in the imploding bubbles. Block helped to design, set up, and calibrate a state-of-the-art neutron and gamma ray detection system for the new experiments.
The research team leaders are all well known authorities in the field of nuclear engineering. Lahey is a fellow of both the American Nuclear Society (ANS) and the American Society of Mechanical Engineers (ASME), and is a member of the National Academy of Engineering (NAE). Block is the longtime director of the Gaerttner Linear Accelerator (LINAC) Laboratory at Rensselaer, and he is also a fellow of the ANS and recipient of their 2005 Seaborg Medal, which recognizes an individual who has made outstanding scientific or engineering research contributions to the development of peaceful uses of nuclear energy. Taleyarkhan, a fellow of the ANS and the program's director, is currently the Ardent Bement Jr. Professor of Nuclear Engineering at Purdue University. Nigmatulin is a visiting scholar at Rensselaer, a former member of the Russian Duma, and the president of the Bashkortonstan branch of the Russian Academy of Sciences (RAS).
About Rensselaer
Rensselaer Polytechnic Institute, founded in 1824, is the nation's oldest technological university. The university offers bachelor's, master's, and doctoral degrees in engineering, the sciences, information technology, architecture, management, and the humanities and social sciences. Institute programs serve undergraduates, graduate students, and working professionals around the world. Rensselaer faculty are known for pre-eminence in research conducted in a wide range of fields, with particular emphasis in biotechnology, nanotechnology, information technology, and the media arts and technology. The Institute is well known for its success in the transfer of technology from the laboratory to the marketplace so that new discoveries and inventions benefit human life, protect the environment, and strengthen economic development.

© 2006 Newswise. All Rights Reserved

* * *
    Relatio, L'Europe en revue / 30.01.2006
    RECHERCHE: Coopération accrue entre l'Union européenne et la Russie dans les nanotechnologies
    Евросоюз намерен активизировать сотрудничество с российскими учеными в области нанотехнологий. Об этом сообщил директор научных программ Еврокомиссии Эцио Андретта. 30 января он посетил Курчатовский центр синхротронного излучения и нанотехнологий и обсудил с руководством центра возможности сотрудничества российских и европейских ученых в области новых технологий.

L'Union européenne entend intensifier sa coopération avec les chercheurs russes en matière de nanotechnologies, a annoncé à RIA Novosti lundi le directeur des programmes scientifiques de la Commission européenne Ezio Andretta. Le représentant de la Commission européenne s'est rendu au Centre Kourtchatov d'étude du rayonnement synchrotronique et de nanotechnologies pour débattre avec les dirigeants du Centre de la question d'une éventuelle coopération des chercheurs russes et européens dans le domaine des technologies modernes.  
"Nous avons débattu lundi de la feuille de route dans le domaine des nanotechnologies et convenu que l'Europe organisera des concours auxquels prendront part l'Union européenne et la Russie", a indiqué Ezio Andretta. Selon lui, de plus vastes possibilités seront ouvertes pour la participation de centres de recherche russes à des projets européens et, en échange, la Russie offre de plus vastes possibilités pour la participation d'organisations et de centres de recherche européens aux projets réalisés en Russie.De son côté, Mikhaïl Kovaltchouk, directeur de l'Institut Kourtchatov et de l'Institut académique de cristallographie a noté que les chercheurs européens et russes ont besoin d'une coopération pour développer efficacement les nanotechnologies. "Etant donné la complexité des nanotechnologies, aucun pays, même disposant d'un potentiel de recherche très développé, n'est en mesure de "couvrir" le champ des nanotechnologies. Nous sommes des voisins proches avec nos partenaires européens, biens des liens historiques et scientifiques nous unissent et je pense que la coopération des chercheurs russes et européens dans le domaine des nanotechnologies représente un élément d'importance dans l'édification du monde au moyen de la science", a ajouté le chercheur russe.

* * *
    Futura Sciences / le 30/01/2006
    Des pellicules de diamants pour renforcer les matériaux
    Московские и красноярские химики разработали способ нанесения алмазного покрытия на различные поверхности. При этом не требуется ни сложной аппаратуры, ни дорогостоящих реактивов.

Les scientifiques de l'Institut de chimie et de technologie chimique de Moscou en collaboration avec l'Institut technique d'Etat de Krasnoïarsk ont développé une technologie de dépôt de films de diamants fins et solides, l'extraction pyrolytique, n'exigeant ni appareil compliqué ni réactifs chers. Les diamants dispersés couvrent les surfaces de pièces métalliques et les rendent plus solides et résistants à l'usure.
Il est possible de synthétiser des nanodiamants par détonation de mélanges explosifs mais les scientifiques russes proposent d'extraire les nanodiamants en suspension dans des solutions aqueuses à l'aide de solvants organiques. Après avoir étudié la stabilité de telles suspensions dans différents liquides, ils ont appris à augmenter la concentration de particules par traitement ultrason.
Les scientifiques ont obtenu des films de nanodiamants sur des surfaces différentes telles que le quartz, le silicium, le verre et le métal et ont étudié la qualité des ces films. Il suffit de plonger le matériau dans la solution, le retirer et faire chauffer à 300 C° pour obtenir des films solides homogènes qui tiennent à la surface. Le diluant se vaporise et le film s'ancre solidement sur la surface. Le film est transparent dans le visible et l'infrarouge et absorbe la lumière dans les ultraviolets.

* * *
    The International Science and Technology Center / 2 Feb 2006
    The puzzle of the iron nucleus
    Уральские ученые, сотрудники Института минералогии и Института геофизики Уральского отделения РАН, предложили новую модель формирования Земли и планет земной группы. Модель отличается от своих предшественниц тем, что удовлетворительно объясняет происхождение плотного железного ядра планеты и силикатной мантии, следовательно, имеет много шансов оказаться истинной. Согласно новой модели, железное ядро у планет земной группы сформировалось на ранней стадии развития, когда размер планеты не превышал нескольких сотен километров. Механизм рождения Земли, предложенный уральскими учеными, не предполагает катастрофических столкновений достаточно крупных планет. Все происходит естественно, быстро и не противоречит современным геохимическим данным.

Urals scientists from the Institute of Mineralogy and the Institute of Geophysics of the Urals Branch RAS have proposed a new model for the formation of the Earth and the plants of the Earth Group. The model differs from its predecessors in that it satisfactorily explains the origin of the dense iron nucleus of the planet and the silicate mantle, which, correspondingly, it has a considerable chance of proving to be true.
According to the new model the iron nucleus of the planets in the Earth Group was formed at the early stage of development when the size of the planet was no greater than a few hundred kilometres. Upon compression of the planet cloud it is the minerals that condense first; minerals that contain silicon and aluminium. It is they that comprised the centre of the embryo of the planet. Iron and nickel entered the next layer and they were covered with other rock types. The future planet was still very small, and therefore, many collisions with other bodies could not heat up its surface. It remained hard, although the internal rock was molten, thanks to the energy from the breakdown of short-lived radioactive aluminium isotopes.
At the early stage of the formation of the planets the collision of two small celestial bodies was commonplace. If these bodies have similar sizes, a partially molten alumosilicate nucleus, a fully molten middle shell, made up of iron, and a hard outer shell, their shells will crack and the molten iron layers of both bodies will merge and form the germ of a new body, the nucleus of which already consists of an iron-nickel alloy. It will be covered above by the destroyed pieces of the shell and a planet of the Earth type will begin to grow. According to the calculations of the scientists the adhesion of planet embryos and the formation of an iron nucleus took from 1 to 10 million years. The redistribution of matter within the new planet did not cause any difficulties that were unavoidable with the current sizes of nucleus and mantle, as both planet embryos were very small.
The mechanism for the birth of the Earth, as proposed by the Urals scientists, does not assume the catastrophic collision of fairly large planets. Everything occurs naturally, rapidly and does not contradict contemporary geochemical data.

© ISTC 1993-2006

* * *
Продолжение дайджеста за ФЕВРАЛЬ 2006 года (часть 2)
январь февраль март апрель май июнь июль август сентябрь октябрь ноябрь декабрь

предыдущий месяц
1998-2006
следующий месяц
[О библиотеке | Академгородок | Новости | Выставки | Ресурсы | Библиография | Партнеры | ИнфоЛоция | Поиск | English]
  Пожелания и письма: www@prometeus.nsc.ru
© 1997-2017 Отделение ГПНТБ СО РАН (Новосибирск)
Статистика доступов: архив | текущая статистика
 

Документ изменен: Mon Mar 5 16:58:44 2012. Размер: 28,474 bytes.
Посещение N 4348 с 03.03.2006