358 research outputs found
On the Resistance Coefficient by the Group of Column in the Open Channel
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive
Para to Ortho transition of metallic dimers on Si(001)
Extensive electronic structure calculations are performed to obtain the
stable geometries of metals like Al, Ga and In on the Si(001) surface at 0.5 ML
and 1 ML coverages. Our results coupled with previous theoretical findings
explain the recent experimental data in a comprehensive fashion. At low
coverages, as shown by previous works, `Para' dimers give the lowest energy
structure. With increasing coverage beyond 0.5 ML, `Ortho' dimers become part
of low energy configurations leading toward a `Para' to `Ortho' transition at 1
ML coverage. For In mixed staggered dimers (`Ortho' and `Para') give the lowest
energy configuration. For Ga, mixed dimers are non-staggered, while for Al
`Para' to `Ortho' transition of dimers is complete. Thus at intermediate
coverages between 0.5 and 1 ML, the `Ortho' and `Para' dimers may coexist on
the surface. Consequently, this may be an explanation of the fact that the
experimental observations can be successfully interpreted using either
orientation. A supported zigzag structure at 0.5 ML, which resembles , does not undergo a dimerization transition, and hence stays
semi-metallic. Also, unlike the soliton formation is ruled out
for this structure.Comment: 8 pages, 6 figure
カク ホウシャ カガク ノ ショウカイ : ジュウゲンソ カガク カラ カンキョウ ホウシャノウ ムキ ブンセキ カガク イヨウ キキ カイハツ マデ
The end of the late19th century, nuclear and radiochemistry was firstly constructed by one of great chemists, Marie Curie. At that time, she had carried out the first discovery of two new elements, polonium and radium, using chemical decomposition and separation methods of the first exercise in radiochemistry of uranium ores. Currently, nuclear and radiochemistry plays an important role in various fundamental and applied research fields from physics, chemistry, and biology, toward the environment, energy, industrial materials, life science, medicine, agriculture, education, and so on. This review is focused mainly on the introduction of current nuclear and radiochemistry, in particular, from the nuclear sciences of transuranium nuclides including recent experimental works of superheavy element chemistry toward radioactivity in the environment, inorganic analytical chemistry and the application of scientific technology to development of medical device
Towards Intelligent Databases
This article is a presentation of the objectives and techniques
of deductive databases. The deductive approach to databases aims at extending
with intensional definitions other database paradigms that describe
applications extensionaUy. We first show how constructive specifications can
be expressed with deduction rules, and how normative conditions can be defined
using integrity constraints. We outline the principles of bottom-up and
top-down query answering procedures and present the techniques used for
integrity checking. We then argue that it is often desirable to manage with
a database system not only database applications, but also specifications of
system components. We present such meta-level specifications and discuss
their advantages over conventional approaches
Recent great impact by an Isotope Separator On-Line(ISOL) in nuclear and radiochemistry
On April 9 2015, the Letter article titled “Measurement of the first ionization potential of lawrencium, element 103” is now published at News and Views on Nature (2015) which has been performed by our remarkably Japanese colleagues of nuclear and radiochemistry at JAEA (Japan Atomic Energy Agency). In this review, the author will state that the isotope separator on-line (ISOL) our regularly used, one of mass separation techniques, with a thermal surface ionization makes possible for determining the ionization potential of lawrencium based on the fruitful fundations of developing the ISOL system until now and also ever studying searches for unknown nuclei and these nuclear decay properties around actinide region in the past 20 years
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