456 research outputs found
Numerical Simulation and Experimental Study on the Interface Bonding of Stainless Steel Clad Plate
The rolling temperature and rate of thickness reduction directly affect the interface bonding quality, mechanical properties and microstructure of stainless steel clad plate. In order to obtain reasonable rolling process parameters, the multi-pass rolling processes of Q345R/316L stainless steel clad plate were simulated by the DEFORM software package. The distributions of stress, strain, and microstructure fields of the clad plate at different rolling temperatures and reduction rates were investigated. The bonding state of the interface was determined and the change rules governing the grain size of the rolled substrate layer also were analyzed. Vacuum hot-rolling tests were carried out to characterize the microstructure and mechanical properties. It was found that the higher the rolling temperature, the lower was the reduction rate needed to realize the interface bonding. However, too high temperatures produce a higher fraction of coarse grains, which affects the overall mechanical properties of the clad plate. It was concluded from the tests and numerical results that rolling temperature of 1150°C and reduction rate exceeding 50%, stainless allow one to produce steel clad plates with high interface bonding quality and excellent microstructure.Показано, что температура прокатки и степень обжатия оказывают влияние на силу сцепления на поверхности раздела, механические свойства и микроструктуру пластины, плакированной нержавеющей сталью. Процесс прокатки за четыре пропуска для пластины, плакированной нержавеющей сталью Q345R/316L, моделировали с помощью программы DEFORM, что позволило рассчитать его рабочие параметры. Исследовано распределение полей напряжений, деформаций и микроструктуры пластины при различной температуре прокатки и степени обжатия. Определена сила сцепления на поверхности раздела, проанализирован гранулометрический состав катаного подслоя при различных температурах. Проведены испытания образцов, полученных горячей вакуумной прокаткой, для оценки микроструктуры и механических свойств. Установлено, что чем выше температура прокатки, тем ниже степень обжатия, необходимая для обеспечения сцепления на поверхности раздела. Однако более высокие температуры вызывают увеличение доли грубых зерен, что оказывает влияние на механические свойства пластины. Экспериментально и численно показано, что температура прокатки в 1150°С и степень обжатия более 50% обеспечивают необходимую силу сцепления и качественную микроструктуру плакированной пластин
Characterization of rate-dependent shear behavior of Zr-based bulk metallic glass using shear-punch testing
Novel D-hordein-like HMW glutenin sequences isolated from Psathyrostachys juncea by thermal asymmetric interlaced PCR
New high-molecular-weight glutenin (HMW glutenin) sequences isolated from six Psathyrostachys juncea accessions by thermal asymmetric interlaced PCR differ from previous sequences from this species. They showed novel modifications in all of the structural domains, with unique C-terminal residues, and their N-terminal lengths were the longest among the HMW glutenins reported to date. In their repetitive domains, there were three repeatable motif units: 13-residue [GYWH(/I/Y)YT(/Q)S(/T)VTSPQQ], hexapeptide (PGQGQQ), and tetrapeptide (ITVS). The 13-residue repeats were restricted to the current sequences, while the tetrapeptides were only shared by D-hordein and the current sequences. However, these sequences were not expressed as normal HMW glutenin proteins because an in-frame stop codon located in the C-termini interrupted the intact open reading frames. A phylogenetic analysis supported different origins of the P. juncea HMW glutenin sequences than that revealed by a previous study. The current sequences showed a close relationship with D-hordein but appeared to be more primitive
Science Development
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68479/2/10.1177_107554708500600404.pd
The lifetime of B_c-meson and some relevant problems
The lifetime of the B_c-meson is estimated with consistent considerations on
all of the heavy mesons () and the double
heavy meson B_c. In the estimate, the framework, where the non-spectator
effects for nonleptonic decays are taken into account properly, is adopted, and
the parameters needed to be fixed are treated carefully and determined by
fitting the available data. The bound-state effects in it are also considered.
We find that in decays of the meson B_c, the QCD correction terms of the
penguin diagrams and the main component terms c_1O_1, c_2O_2 of the effective
interaction Lagrangian have direct interference that causes an enhancement
about 3 ~ 4% in the total width of the B_c meson.Comment: 27 pages, 0 figur
In search of nonribosomal nucleolar protein function and regulation
The life of the nucleolus has proven to be more colorful and multifaceted than had been envisioned a decade ago. A large number of proteins found in this subnuclear compartment have no identifiable tie either to the ribosome biosynthetic pathway or to the other newly established activities occurring within the nucleolus. The questions of how and why these proteins end up in this subnuclear compartment remain unanswered and are the focus of intense current interest. This review discusses our thoughts on the discovery of nonribosomal proteins in the nucleolus
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
BESII Detector Simulation
A Monte Carlo program based on Geant3 has been developed for BESII detector
simulation. The organization of the program is outlined, and the digitization
procedure for simulating the response of various sub-detectors is described.
Comparisons with data show that the performance of the program is generally
satisfactory.Comment: 17 pages, 14 figures, uses elsart.cls, to be submitted to NIM
Measurement of branching fractions for the inclusive Cabibbo-favored ~K*0(892) and Cabibbo-suppressed K*0(892) decays of neutral and charged D mesons
The branching fractions for the inclusive Cabibbo-favored ~K*0 and
Cabibbo-suppressed K*0 decays of D mesons are measured based on a data sample
of 33 pb-1 collected at and around the center-of-mass energy of 3.773 GeV with
the BES-II detector at the BEPC collider. The branching fractions for the
decays D+(0) -> ~K*0(892)X and D0 -> K*0(892)X are determined to be BF(D0 ->
\~K*0X) = (8.7 +/- 4.0 +/- 1.2)%, BF(D+ -> ~K*0X) = (23.2 +/- 4.5 +/- 3.0)% and
BF(D0 -> K*0X) = (2.8 +/- 1.2 +/- 0.4)%. An upper limit on the branching
fraction at 90% C.L. for the decay D+ -> K*0(892)X is set to be BF(D+ -> K*0X)
< 6.6%
Study of
New data are presented on from a sample of 58M
events in the upgraded BES II detector at the BEPC. There is a
conspicuous signal for and a peak at higher mass which
may be fitted with . From a combined analysis with
data, the branching ratio
is at the 95%
confidence level.Comment: 11 pages, 5 figures. Submitted to Phys. Lett.
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