1,505 research outputs found
Study of the Three Component System Diethyl Ether-Water-Magnesium Bromide at 25 C. (Abstract)
Varying amounts of the three components were brought together in a tube and allowed to come to equilibrium at 25° C. and at atmospheric pressure. The composition of each of the condensed phases, solid and liquid, was determined by analysis and a triangular three component diagram of the phases in equilibrium was made. From the areas, lines and points of the phase diagram, the following information was obtained. Two independent pairs of partly miscible liquids were found: one consisting of a water and an ether layer with a small amount of magnesium bromide dissolved in the ether layer, the other pair consisting essentially of two ether layers, with considerable magnesium bromide in one of the layers. Two solids were found that can exist in equilibrium with liquid phases at 25° C., these being magnesium bromide hexahydrate and magnesium bromide di-ether ate. No evidence was found for the existence of a mixed solvate or the basic magnesium bromide di-etherate as claimed by Menschutkin
Требования к узлу сопряжения секций геохода
Проведен анализ работы узла сопряжения секций (УСС) геохода. Сформированы требования к узлу сопряжения секций геохода.The analysis of the operation of the bearing unit of the geokhod is carried out. The requirements for the bearing unit of the geokhod are formed
NN interaction in a Goldstone boson exchange model
Adiabatic nucleon-nucleon potentials are calculated in a six-quark
nonrelativistic chiral constituent quark model where the Hamiltonian contains a
linear confinement and a pseudoscalar meson (Goldstone boson) exchange
interaction between quarks. Calculations are performed both in a cluster model
and a molecular orbital basis, through coupled channels. In both cases the
potentials present an important hard core at short distances, explained through
the dominance of the [51]_{FS} configuration, but do not exhibit an attractive
pocket. We add a scalar meson exchange interaction and show how it can account
for some middle-range attraction.Comment: 32 pages with 12 eps figures incorporated, RevTeX. Final version
published in PR
Closedness type regularity conditions for surjectivity results involving the sum of two maximal monotone operators
In this note we provide regularity conditions of closedness type which
guarantee some surjectivity results concerning the sum of two maximal monotone
operators by using representative functions. The first regularity condition we
give guarantees the surjectivity of the monotone operator , where and and are maximal monotone operators on
the reflexive Banach space . Then, this is used to obtain sufficient
conditions for the surjectivity of and for the situation when belongs
to the range of . Several special cases are discussed, some of them
delivering interesting byproducts.Comment: 11 pages, no figure
Phenomenological study of hadron interaction models
We present a phenomenological study of three models with different effective
degrees of freedom: a Goldstone Boson Exchange (GBE) model which is based on
quark-meson couplings, the quark delocalization, color screening model (QDCSM)
which is based on quark-gluon couplings with delocalized quark wavefunctions,
and the Fujiwara-Nijmegen (FN) mixed model which includes both quark-meson and
quark-gluon couplings. We find that for roughly two-thirds of 64 states
consisting of pairs of octet and decuplet baryons, the three models predict
similar effective baryon-baryon interactions. This suggests that the three very
different models, based on different effective degrees of freedom, are
nonetheless all compatible with respect to baryon spectra and baryon-baryon
interactions. We also discuss the differences between the three models and
their separate characteristics.Comment: 30 pages latex, 7 tables, 12 figs; submitted to Phys. Rev.
A new study of the spectroscopic binary 7 Vul with a Be star primary
We confirmed the binary nature of the Be star 7~Vul, derived a~more accurate
spectroscopic orbit with an orbital period of (69.4212+/-0.0034) d, and
improved the knowledge of the basic physical elements of the system. Analyzing
available photometry and the strength of the \ha emission, we also document the
long-term spectral variations of the Be primary. In addition, we confirmed
rapid light changes with a~period of 0.5592 d, which is comparable to the
expected rotational period of the Be primary, but note that its amplitude and
possibly its period vary with time. We were able to disentangle only the He I
6678 A line of the secondary, which could support our tentative conclusion that
the secondary appears to be a hot subdwarf. A search for this object in
high-dispersion far-UV spectra could provide confirmation. Probable masses of
the binary components are ()~Mnom \ and ()~Mnom. If the
presence of a hot subdwarf is firmly confirmed, 7 Vul might be identified as a
rare object with a B4-B5 primary; all Be + hot subdwarf systems found so far
contain B0-B3 primaries.Comment: 17 pages, 23 figures, accepted for publication in Astronomy and
Astrophysic
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