315 research outputs found
Effect of Cyclic Stresses below the Endurance Limit on the Fatigue Life of 40Cr Steel
The effect of cyclic stresses below the endurance limit on the fatigue life of 40Cr medium-strength carbon steel is studied. Conventional constant-amplitude cyclic tests and specially designed variableamplitude ones are conducted under torsional loading at the stress ratio R = 0.1. The results show that the strengthening effect of cyclic stresses below the endurance limit can be reached if they are applied prior to the exceeding ones. Moreover, the stress amplitude, number of cycles and load sequence are found to be the three major strengthening effect-controlling factors.ΠΠ·ΡΡΠ΅Π½ΠΎ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΡΠΈΠΊΠ»ΠΈΡΠ΅ΡΠΊΠΈΡ
Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠΉ Π½ΠΈΠΆΠ΅ ΠΏΡΠ΅Π΄Π΅Π»Π° Π²ΡΠ½ΠΎΡΠ»ΠΈΠ²ΠΎΡΡΠΈ Π½Π° ΡΡΡΠ°Π»ΠΎΡΡΠ½ΡΡ Π΄ΠΎΠ»Π³ΠΎΠ²Π΅ΡΠ½ΠΎΡΡΡ ΡΠ³Π»Π΅ΡΠΎΠ΄ΠΈΡΡΠΎΠΉ ΡΡΠ°Π»ΠΈ ΡΡΠ΅Π΄Π½Π΅ΠΉ ΠΏΡΠΎΡΠ½ΠΎΡΡΠΈ 40Cr. ΠΡΠΏΠΎΠ»Π½Π΅Π½Ρ ΡΡΠ°Π½Π΄Π°ΡΡΠ½ΡΠ΅ ΡΠΈΠΊΠ»ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈΡΠΏΡΡΠ°Π½ΠΈΡ Ρ ΠΏΠΎΡΡΠΎΡΠ½Π½ΠΎΠΉ Π°ΠΌΠΏΠ»ΠΈΡΡΠ΄ΠΎΠΉ ΠΈ ΡΠΏΠ΅ΡΠΈΠ°Π»ΡΠ½ΠΎ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π½ΠΎΠ΅ ΠΈΡΠΏΡΡΠ°Π½ΠΈΠ΅ Ρ ΠΏΠ΅ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ Π°ΠΌΠΏΠ»ΠΈΡΡΠ΄ΠΎΠΉ ΠΏΡΠΈ ΠΊΡΡΡΡΡΠ΅ΠΌ ΡΡΠΈΠ»ΠΈΠΈ ΠΈ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ΅ Π°ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ R = 0,1. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΡΡΡΠ΅ΠΊΡ ΡΠΏΡΠΎΡΠ½Π΅Π½ΠΈΡ ΠΎΡ ΡΠΈΠΊΠ»ΠΈΡΠ΅ΡΠΊΠΈΡ
Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠΉ Π½ΠΈΠΆΠ΅ ΠΏΡΠ΅Π΄Π΅Π»Π° Π²ΡΠ½ΠΎΡΠ»ΠΈΠ²ΠΎΡΡΠΈ Π΄ΠΎΡΡΠΈΠ³Π°Π΅ΡΡΡ ΠΏΡΠΈ ΠΈΡ
ΠΏΡΠΈΠ»ΠΎΠΆΠ΅Π½ΠΈΠΈ Π΄ΠΎ Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠΉ, ΠΏΡΠ΅Π²ΡΡΠ°ΡΡΠΈΡ
ΡΡΠΎΡ ΠΏΡΠ΅Π΄Π΅Π». Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ Π°ΠΌΠΏΠ»ΠΈΡΡΠ΄Π° Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠΉ, ΡΠΈΡΠ»ΠΎ ΡΠΈΠΊΠ»ΠΎΠ² ΠΈ ΡΡ
Π΅ΠΌΠ° Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΡ ΡΠ²Π»ΡΡΡΡΡ ΡΡΠ΅ΠΌΡ ΠΎΡΠ½ΠΎΠ²Π½ΡΠΌΠΈ ΡΠ°ΠΊΡΠΎΡΠ°ΠΌΠΈ, ΠΊΠΎΠ½ΡΡΠΎΠ»ΠΈΡΡΡΡΠΈΠΌΠΈ ΡΡΡΠ΅ΠΊΡ ΡΠΏΡΠΎΡΠ½Π΅Π½ΠΈΡ
X-ray diffraction measurements of the c-axis Debye-Waller factors of YBa2Cu3O7 and HgBa2CaCu2O6
We report the first application of x-rays to the measurement of the
temperature dependent Bragg peak intensities to obtain Debye-Waller factors on
high-temperature superconductors. Intensities of (0,0,l) peaks of YBa2Cu3O7 and
HgBa2CaCu2O6 thin films are measured to obtain the c-axis Debye-Waller factors.
While lattice constant and some Debye-Waller factor measurements on high Tc
superconductors show anomalies at the transition temperature, our measurements
by x-ray diffraction show a smooth transition of the c-axis Debye-Waller
factors through T. This suggests that the dynamic displacements of the
heavy elements along the c-axis direction in these compounds do not have
anomalies at Tc. This method in combination with measurements by other
techniques will give more details concerning dynamics of the lattice.Comment: 4 pages, 2 figures. To be published in Physical Review B (Brief
Report
Reaction of Water-Saturated Supercritical CO2 with Forsterite: Evidence for Magnesite Formation at Low Temperatures
\psi(2S) Decays into \J plus Two Photons
Using \gamma \gamma J/\psi, J/\psi \ra e^+ e^- and events
from a sample of \psip decays collected with the BESII
detector, the branching fractions for \psip\ra \pi^0\J, \eta\J, and
\psi(2S)\ar\gamma\chi_{c1},\gamma\chi_{c2}\ar\gamma\gamma\jpsi are measured
to be B(\psip\ra \pi^0\J) = (1.43\pm0.14\pm0.13)\times 10^{-3}, B(\psip\ra
\eta\J) = (2.98\pm0.09\pm0.23)%,
B(\psi(2S)\ar\gamma\chi_{c1}\ar\gamma\gamma\jpsi) = (2.81\pm0.05\pm 0.23)%,
and B(\psi(2S)\ar\gamma\chi_{c2}\ar\gamma\gamma\jpsi) = (1.62\pm0.04\pm
0.12)%.Comment: 7 pages, 6 figures. submitted to Phys. Rev.
Search for the Lepton Flavor Violation Processes and
The lepton flavor violation processes and are
searched for using a sample of 5.8 events collected with
the BESII detector. Zero and one candidate events, consistent with the
estimated background, are observed in and
decays, respectively. Upper limits on the branching ratios are determined to be
and at the 90% confidence level (C.L.).Comment: 9 pages, 2 figure
Measurements of the observed cross sections for exclusive light hadrons containing at , 3.650 and 3.6648 GeV
By analyzing the data sets of 17.3, 6.5 and 1.0 pb taken,
respectively, at , 3.650 and 3.6648 GeV with the BES-II
detector at the BEPC collider, we measure the observed cross sections for
, , ,
and at the three energy
points. Based on these cross sections we set the upper limits on the observed
cross sections and the branching fractions for decay into these
final states at 90% C.L..Comment: 7 pages, 2 figure
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
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