21,789 research outputs found
Kinematical Constraints on QCD Factorization in the Drell-Yan Process
We study factorization schemes for parton shower models in hadron-hadron
collisions. As an example, we calculate lepton pair production mediated by a
virtual photon in quark--anti-quark annihilation, and we compare factorized
cross sections obtained in the conventional scheme with those
obtained in a factorization scheme in which a kinematical constraint due to
parton radiation is taken into account. We discuss some properties of
factorized cross sections.Comment: 10 pages, PTPTeX.sty, 1 Postscript figur
Erratum: Theory of charge transport in diffusive normal metal/unconventional singlet superconductor contacts [Phys. Rev. B 69, 144519 (2004)]
Applied Science
Cooperation between Japanese Linguistics and Japanese Language Education
In this paper, we consider the possibility of cooperation between Japanese linguistics and Japanese language education using the teaching material draft of ‘citation’ as a subject matter. In some instances, the work of applying new learning items added by the revision of the Government Course Curriculum Guidelines to the level of specific linguistic expression has not been done adequately. The first step in cooperation between Japanese linguistics and Japanese language education is to carry out such work on the Japanese linguistics end and to propose teaching material drafts.
要旨本稿では、「引用」の教材案を題材に、日本語学と国語科教育との協同の可能性について考えた。『学習指導要領』の改訂によって新たに加えられた学習事項については、具体的な言語表現のレベルに落とし込む作業が十分になされていない場合がある。このような作業を日本語学側で行い、教材案を提案していくことに日本語学と国語科教育との協同の第一歩がある
Envelope Expansion with Core Collapse. III. Similarity Isothermal Shocks in a Magnetofluid
We explore MHD solutions for envelope expansions with core collapse (EECC)
with isothermal MHD shocks in a quasi-spherical symmetry and outline potential
astrophysical applications of such magnetized shock flows. MHD shock solutions
are classified into three classes according to the downstream characteristics
near the core. Class I solutions are those characterized by free-fall collapses
towards the core downstream of an MHD shock, while Class II solutions are those
characterized by Larson-Penston (LP) type near the core downstream of an MHD
shock. Class III solutions are novel, sharing both features of Class I and II
solutions with the presence of a sufficiently strong magnetic field as a
prerequisite. Various MHD processes may occur within the regime of these
isothermal MHD shock similarity solutions, such as sub-magnetosonic
oscillations, free-fall core collapses, radial contractions and expansions. We
can also construct families of twin MHD shock solutions as well as an
`isothermal MHD shock' separating two magnetofluid regions of two different yet
constant temperatures. The versatile behaviours of such MHD shock solutions may
be utilized to model a wide range of astrophysical problems, including star
formation in magnetized molecular clouds, MHD link between the asymptotic giant
branch phase to the proto-planetary nebula phase with a hot central magnetized
white dwarf, relativistic MHD pulsar winds in supernova remnants, radio
afterglows of soft gamma-ray repeaters and so forth.Comment: 21 pages, 33 figures, accepted by MNRA
Anomalous proximity effect in d-wave superconductors
The anomalous proximity effect between a d-wave superconductor and a surface
layer with small electronic mean free path is studied theoretically in the
framework of the Eilenberger equations. The angular and spatial structure of
the pair potential and the quasiclassical propagators in the interface region
is calculated selfconsistently. The variation of the spatially-resolved
quasiparticle density of states from the bulk to the surface is studied. It is
shown that the isotropic gapless superconducting state is induced in the
disordered layer.Comment: 6 pages, 5 postscript figures. Submitted to Phys.Rev.
How Accurate Must Potentials Be for Successful Modeling of Protein Folding?
Protein sequences are believed to have been selected to provide the stability
of, and reliable renaturation to, an encoded unique spatial fold. In recently
proposed theoretical schemes, this selection is modeled as ``minimal
frustration,'' or ``optimal energy'' of the desirable target conformation over
all possible sequences, such that the ``design'' of the sequence is governed by
the interactions between monomers. With replica mean field theory, we examine
the possibility to reconstruct the renaturation, or freezing transition, of the
``designed'' heteropolymer given the inevitable errors in the determination of
interaction energies, that is, the difference between sets (matrices) of
interactions governing chain design and conformations, respectively. We find
that the possibility of folding to the designed conformation is controlled by
the correlations of the elements of the design and renaturation interaction
matrices; unlike random heteropolymers, the ground state of designed
heteropolymers is sufficiently stable, such that even a substantial error in
the interaction energy should still yield correct renaturation.Comment: 28 pages, 3 postscript figures; tared, compressed, uuencode
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