426 research outputs found
Impact of the aqueous corrosion induced alteration layer on mechanical properties of pharmaceutical glasses.
It is known that network modifying ions (such as alkali or alkaline earth ions) make glasses susceptible to aqueous corrosion, resulting in the alteration of their surface layers. However, the effect of the altered layers on the mechanical properties of glasses has not been well understood. In this work we study this effect using the pharmaceutical boroaluminosilicate (BAS) glasses as objects by performing nano- and macroscale mechanical tests. The results show that extending the corrosion time increases the thickness of the alteration layer of the BAS glass. The water-related species in the alteration layer lowers the nanohardness, the reduced modulus, the nanowear resistance and Vickers hardness. The corrosion-induced “silica-like” structure in alteration layer benefits the densification of the subsurface caused by nanoindentation and nanowear, and thereby enhances the fracture toughness of the BAS glass. The correlation between the water content in the alteration layer and the mechanical properties has been revealed. This work is instrumental in the design of the next generation of pharmaceutical glasses with higher toughness
Influence of micron WC addition on the microstructure and mechanical properties of ultrafine WC–Co cemented carbides at the elevated temperature
In this paper, the influence of micron-grained WC additions with the different grain sizes on the microstructure and hardness of ultrafine WC–Co cemented carbides at the elevated temperature were investigated by the scanning electron microscope and mechanical properties test. The Vickers hardness and transverse rupture strength of hardmetals were measured at temperatures ranging from room temperature to 800 °C. The results show that the addition of micron-sized WC particles can lead to the increase of fracture toughness and slow the decreasing of hardness at the elevated temperature.Досліджено вплив добавок WC з зернами різних мікронних розмірів на мікроструктуру і твердість надтвердого WC–Co-сплаву при підвищеній температурі за допомогою скануючого електронного мікроскопу і проведено випробування його механічних властивостей. Твердість за Віккерсом і поперечну міцність на розрив твердих металів вимірювали у діапазоні від кімнатної температури до 800 °С. Результати показали, що добавка WС-частинок мікронних розмірів може призвести до збільшення тріщиностійкості і уповільнити зменшення твердості при підвищеній температурі.Исследовано влияние добавок WС с зернами различных микронных размеров на микроструктуру и твердость сверхтвердого WC–Co-сплава при повышенной температуре с помощью сканирующего электронного микроскопа и проведено испытание его механических свойств. Твердость по Виккерсу и поперечную прочность на разрыв твердых металлов измеряли в диапазоне от комнатной температуры до 800 °C. Результаты показали, что добавка WС-частиц микронных размеров может привести к увеличению трещиностойкости и замедлить уменьшение твердости при повышенной температуре
Time-lagged study on psychological contract breach, perceived organizational support and turnover intention of general practitioners
Objective To analyze teh relationship between perceived organizational support, psychological contract breach and turnover intention, so dat to provide a new idea for teh improvement of incentives for general practitioners.
Mehtods During teh period from June to December 2016, two questionnaire surveys were conducted among teh general practitioners of teh Community Health Centers in Pudong New Area, Shanghai. Teh first survey measured demographic sociology information, perceived organizational support, and psychological contract breach. Teh second survey measured turnover intention. Data analysis was performed using SPSS 24.0 and AMOS 24.0 statistical software.
Results 1145 GPs got score of 4.59±0.85 in perceived organizational support, score of 2.87±0.53 in psychological contract breach, and score of 2.26±0.95 in turnover intention. Psychological contract breach and perceived organizational support had a negative effect on turnover intention, and psychological contract breach had a positive effect on perceived organizational support, and perceived organizational support had a partial mediation role in psychological contract breach and turnover intention.
Conclusion Teh incentive measures for general practitioners in Pudong New Area of Shanghai need to be further improved from teh aspects of strengtaning interpretation and guaranteeing implementation, and emphasis on career development.info:eu-repo/semantics/acceptedVersio
Theoretical study of the two-proton halo candidate Ne including contributions from resonant continuum and pairing correlations
With the relativistic Coulomb wave function boundary condition, the energies,
widths and wave functions of the single proton resonant orbitals for Ne
are studied by the analytical continuation of the coupling constant (ACCC)
approach within the framework of the relativistic mean field (RMF) theory.
Pairing correlations and contributions from the single-particle resonant
orbitals in the continuum are taken into consideration by the resonant
Bardeen-Cooper-Schrieffer (BCS) approach, in which constant pairing strength is
used. It can be seen that the fully self-consistent calculations with NL3 and
NLSH effective interactions mostly agree with the latest experimental
measurements, such as binding energies, matter radii, charge radii and
densities. The energy of 2s orbital is slightly higher than that
of orbital, and the occupation probability of the
2s orbital is about 20%, which are in accordance with the
shell model calculation and three-body model estimation
Cosmological evolution and statefinder diagnostic for new holographic dark energy model in non flat universe
In this paper, the holographic dark energy model with new infrared cut-off
proposed by Granda and Oliveros has been investigated in spatially non flat
universe. The dependency of the evolution of equation of state, deceleration
parameter and cosmological evolution of Hubble parameter on the parameters of
new HDE model are calculated. Also, the statefinder parameters and in
this model are derived and the evolutionary trajectories in plane are
plotted. We show that the evolutionary trajectories are dependent on the model
parameters of new HDE model. Eventually, in the light of SNe+BAO+OHD+CMB
observational data, we plot the evolutionary trajectories in and
planes for best fit values of the parameters of new HDE model.Comment: 11 pages, 5 figures, Accepted by Astrophys. Space Sc
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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