527 research outputs found
Contact Deformation Behavior of an Elastic Silicone/SiC Abrasive in Grinding and Polishing
An elastic abrasive of the new type having the advantage of effectively controlled contact pressure and uniform deformation was developed. It provides complete lamination of the surface, effective treatment of the curved mold cavity, as well as improves the processing efficiency. It permits of fine cavity surface finishing.Розроблено пружний абразив нового типу, що дозволяє ефективно регулювати контактний тиск у поєднанні з рівномірним деформуванням. Пружний абразив забезпечує повне ламінування поверхні, збільшує ефективність обробки вигнутої порожнини ливарної форми та дозволяє виконувати тонку обробку поверхні порожнини.Разработан упругий абразив нового типа, позволяющий эффективно регулировать контактное давление в сочетании с равномерным деформированием. Упругий абразив обеспечивает полное ламинирование поверхности и эффективную обработку изогнутой полости литейной формы, а также позволяет выполнять тонкую отделочную обработку поверхности полости
Hydrodynamic Limit of the Boltzmann Equation with Contact Discontinuities
The hydrodynamic limit for the Boltzmann equation is studied in the case when
the limit system, that is, the system of Euler equations contains contact
discontinuities. When suitable initial data is chosen to avoid the initial
layer, we prove that there exists a unique solution to the Boltzmann equation
globally in time for any given Knudsen number. And this family of solutions
converge to the local Maxwellian defined by the contact discontinuity of the
Euler equations uniformly away from the discontinuity as the Knudsen number
tends to zero. The proof is obtained by an appropriately chosen
scaling and the energy method through the micro-macro decomposition.Comment: 34 pages. submitte
Partial wave analysis of J/\psi \to \gamma \phi \phi
Using events collected in the BESII detector, the
radiative decay is
studied. The invariant mass distribution exhibits a near-threshold
enhancement that peaks around 2.24 GeV/.
A partial wave analysis shows that the structure is dominated by a
state () with a mass of
GeV/ and a width of GeV/. The
product branching fraction is: .Comment: 11 pages, 4 figures. corrected proof for journa
Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays
By analyzing about 33 data sample collected at and around 3.773
GeV with the BES-II detector at the BEPC collider, we directly measure the
branching fractions for the neutral and charged inclusive semimuonic decays
to be and , and determine the ratio of the two branching
fractions to be
A study of charged kappa in
Based on events collected by BESII, the decay
is studied. In the invariant mass
spectrum recoiling against the charged , the charged
particle is found as a low mass enhancement. If a Breit-Wigner function of
constant width is used to parameterize the kappa, its pole locates at MeV/. Also in this channel,
the decay is observed for the first time.
Its branching ratio is .Comment: 14 pages, 4 figure
Measurements of the observed cross sections for exclusive light hadron production in e^+e^- annihilation at \sqrt{s}= 3.773 and 3.650 GeV
By analyzing the data sets of 17.3 pb taken at GeV
and 6.5 pb taken at GeV with the BESII detector at the
BEPC collider, we have measured the observed cross sections for 12 exclusive
light hadron final states produced in annihilation at the two energy
points. We have also set the upper limits on the observed cross sections and
the branching fractions for decay to these final states at 90%
C.L.Comment: 8 pages, 5 figur
Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e, and J/Psi --> D0bar e+ e-
We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi -->
D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7
J/Psi events collected with the BESII detector at the BEPC. No excess of signal
above background is observed, and 90% confidence level upper limits on the
branching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi
--> D- e+ nu_e + c.c.) D0bar e+ e- + c.c.)<1.1*10^-5Comment: 10 pages, 4 figure
Measurements of J/psi Decays into 2(pi+pi-)eta and 3(pi+pi-)eta
Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector,
the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are
measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and
(7.24+-0.96+-1.11)X10^{-4}, respectively.Comment: 11 pages, 6 figure
Measurements of the Mass and Full-Width of the Meson
In a sample of 58 million events collected with the BES II detector,
the process J/ is observed in five different decay
channels: , , (with ), (with
) and . From a combined fit of all five
channels, we determine the mass and full-width of to be
MeV/ and
MeV/.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.
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