310 research outputs found
Effect of Carburizing and Shot Peening on the Microstructure and Surface Properties of 17-CrNi6-Mo Steel
Carburizing and shot peening are commonly accepted surface treatment methods used to improve the surface properties of materials. Researchers are making attempts to optimize their application for obtaining superior mechanical properties. However, there are few comprehensive reports on this problem. The combination of carburizing and shot peening is used for the surface treatment of 17-CrNi6-Mo steel. This is followed by detailed analysis employing optical and scanning electron microscopy, microhardness testing, surface roughness measurements, and the measurement of residual stresses using X-ray diffraction. The results show that shot peening can further improve the microstructure and surface properties of carburized specimens since it induced the phase transformation of a carburized layer. Moreover, simulation of the phase composition variation curve along with the change in the carbon content and the continuous cooling transformation (CCT) curve of the specimen is also presented. The results are used to elucidate the carburizing effect on a 17-CrNi6-Mo steel surface microstructure.Цементация и дробеструйная обработка общепринятые методы поверхностной обработки, используемые для улучшения поверхностных свойств материалов. Ученые проводят работы в направлении оптимизации их применения с целью обеспечения высоких механических свойств. Однако существует лишь несколько подробных исследований, посвященных их применению. Комбинацию цементации и дробеструйной обработки используют для поверхностной обработки стали 17-CrNi6-Mo. После обработки проводили подробный анализ поверхности материала с использованием оптической и сканирующей электронной микроскопии, измерений ее микротвердости и шероховатости, а также остаточных напряжений с помощью рентгенографии. Результаты показывают, что дробеструйная обработка может дополнительно улучшить микроструктуру и поверхностные свойства науглероженных образцов, поскольку она вызывает фазовое превращение науглероженного слоя. Выполнено моделирование кривой вариации фазового состава с одновременным изменением содержания углерода, а также кривой превращения при непрерывном охлаждении образца. Полученные результаты используются для установления эффекта влияния цементации на микроструктуру поверхности стали 17-CrNi6-Mo
Succinyl-CoA:3-ketoacid coenzyme A transferase (SCOT): development of an antibody to human SCOT and diagnostic use in hereditary SCOT deficiency
AbstractSuccinyl-CoA:3-ketoacid CoA transferase (SCOT) is a key enzyme for ketone body utilization. Hereditary SCOT deficiency in humans (McKusick catalogue number 245050) is characterized by intermittent ketoacidotic attacks and permanent hyperketonemia. Since previously-available antibody to rat SCOT did not crossreact with human SCOT, we developed an antibody against recombinant human SCOT expressed in a bacterial system. The recombinant SCOT was insoluble except under denaturing conditions. Antibody raised to this polypeptide recognized denatured SCOT and proved useful for immunoblot analysis. On immunoblots, SCOT was easily detectable in control fibroblasts and lymphocytes but was detected neither in fibroblast extracts from four SCOT-deficient patients, nor in lymphocytes from two SCOT-deficient patients. These data indicate that immunoblot analysis is useful for diagnosis of SCOT deficiency in combination with enzyme assay
EGAM Induced by Energetic-electrons and Nonlinear Interactions among EGAM, BAEs and Tearing Modes in a Toroidal Plasma
In this letter, it is reported that the first experimental results are
associated with the GAM induced by energetic electrons (eEGAM) in HL-2A Ohmic
plasma. The energetic-electrons are generated by parallel electric fields
during magnetic reconnection associated with tearing mode (TM). The eEGAM
localizes in the core plasma, i.e. in the vicinity of q=2 surface, and is very
different from one excited by the drift-wave turbulence in the edge plasma. The
analysis indicated that the eEGAM is provided with the magnetic components,
whose intensities depend on the poloidal angles, and its mode numbers are
jm/nj=2/0. Further, there exist intense nonlinear interactions among eEGAM,
BAEs and strong tearing modes (TMs). These new findings shed light on the
underlying physics mechanism for the excitation of the low frequency (LF)
Alfv\'enic and acoustic uctuations.Comment: 5 pages,4 figure
Distributed phase-covariant cloning with atomic ensembles via quantum Zeno dynamics
We propose an interesting scheme for distributed orbital state quantum
cloning with atomic ensembles based on the quantum Zeno dynamics. These atomic
ensembles which consist of identical three-level atoms are trapped in distant
cavities connected by a single-mode integrated optical star coupler. These
qubits can be manipulated through appropriate modulation of the coupling
constants between atomic ensemble and classical field, and the cavity decay can
be largely suppressed as the number of atoms in the ensemble qubits increases.
The fidelity of each cloned qubit can be obtained with analytic result. The
present scheme provides a new way to construct the quantum communication
network.Comment: 5 pages, 4 figure
Partial Wave Analysis of
BES data on are presented. The
contribution peaks strongly near threshold. It is fitted with a
broad resonance with mass MeV, width MeV. A broad resonance peaking at 2020 MeV is also required
with width MeV. There is further evidence for a component
peaking at 2.55 GeV. The non- contribution is close to phase
space; it peaks at 2.6 GeV and is very different from .Comment: 15 pages, 6 figures, 1 table, Submitted to PL
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.
Measurements of decays into Vector- Tensor final states
Decays of the into vector plus tensor meson final states have been
studied with 14 million events collected with the BESII detector.
Branching fractions of \psi(2S) \rt \omega f_{2}(1270), ,
and are
determined. They improve upon previous BESI results and confirm the violation
of the "12%" rule for decays to VT channels with higher precision.Comment: 7 pages, 7 figures and 2 table
Measurement of Branching Ratios for Hadronic Decays
In a sample of 58 million events collected with the BES II detector,
the process J/ is observed in five decay channels: , , (with
), (with ) and . From
these signals, we determine ,
, ,
and .Comment: 8 pages, 1 figures and 4 table. Submitted to Phys. Lett.
Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-
Evidence of decays to a non- final state is
observed. A total of \psi(3770) \to \PPJP events are
obtained from a data sample of 27.7 taken at center-of-mass
energies around 3.773 GeV using the BES-II detector at the BEPC. The branching
fraction is determined to be BF(\psi(3770) \to \PPJP)=(0.34\pm 0.14 \pm
0.09)%, corresponding to the partial width of \Gamma(\psi(3770) \to \PPJP) =
(80 \pm 33 \pm 23) keV.Comment: 8 pages, 7 figures, Submitted to Physics Letters
Measurements of J/psi --> p \bar{p}
The process J/\psi --> p \bar{p} is studied using 57.7 X 10^6 J/\psi events
collected with the BESII detector at the Beijing Electron Positron Collider.
The branching ratio is determined to be Br(J/\psi --> p \bar{p})=(2.26 +- 0.01
+- 0.14) X 10^{-3}, and the angular distribution is well described by
\frac{dN}{d cos\theta_p}=1+\alpha\cos^2\theta_p with \alpha = 0.676 +- 0.036 +-
0.042, where \theta_p is the angle between the proton and beam directions. The
value of \alpha obtained is in good agreement with the predictions of
first-order QCD.Comment: 6 pages, 2 figures, RevTex4, Submitted to Phys.Lett.
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