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InPBi Single Crystals Grown by Molecular Beam Epitaxy
InPBi was predicted to be the most robust infrared optoelectronic material but also the most difficult to synthesize within In-VBi (V = P, As and Sb) 25 years ago. We report the first successful growth of InPBi single crystals with Bi concentration far beyond the doping level by gas source molecular beam epitaxy. The InPBi thin films reveal excellent surface, structural and optical qualities making it a promising new III–V compound family member for heterostructures. The Bi concentration is found to be 2.4 ± 0.4% with 94 ± 5% Bi atoms at substitutional sites. Optical absorption indicates a band gap of 1.23 eV at room temperature while photoluminescence shows unexpectedly strong and broad light emission at 1.4–2.7 μm which can't be explained by the existing theory
TNF-α and TNF-β Gene Polymorphism in Saudi Rheumatoid Arthritis Patients
Background Tumor necrosis factor (TNF)-α and -β are cytokines with a wide range of inflammatory, apoptotic and immunomodulatory activities. TNF-α promoter –308 G < A polymorphism has been reported to be associated with rheumatoid arthritis (RA) with inconsistent results. Objective The aim of this study is to elucidate a possible association of TNF-α (G–308A) and TNF-β (A+252G) polymorphisms with the susceptibility of RA in Saudi patients. Patients and Methods This case control study consisted of 232 Saudi subjects including 106 RA patients and 126 matched controls. Genomic DNA was extracted using QIAamp R DNA mini kit (Qiagen CA, USA). TNF-α and TNF-β genes were amplified using Arms primers. Results The frequencies of TNF-α (–308) allele G and genotype GG were significantly higher in RA patients as compared to controls while allele A and genotype AA were predominant in control group. On the other hand the frequency of TNF-β (+252) GG and AA genotypes were significantly higher in RA patients as compared to controls while GA genotype was predominant in controls. It was inferred that genotype GG positive individuals at position –308 of TNF-α were susceptible to RA while genotype AA might has a protective effect on RA susceptibility in Saudis. Whereas GG and AA genotype of TNF-β at +252 position might exert additive susceptibility to RA and GA might be refractory. However, there was no significant association between duration of morning stiffness, RF positivity and number of joints involved and distribution of alleles/genotypes of TNF-α (–308) or TNF-β (+252) polymorphism. It may be concluded that the TNF-α (–308) and TNF-β (+252) polymorphisms might influence the susceptibility to RA in Saudi population. These results might have prognostic value for future clinical observations
Effects of Sc and Zr on the texture and mechanical anisotropy of high strength Al - Zn - Mg alloy sheets
Texture, mechanical anisotropy and microstructure of aged Al–Zn–Mg, Al–Zn–Mg–0.1Sc–0.1Zr and Al–Zn–Mg–0.25Sc–0.1Zr (wt.%) alloy sheets were investigated by tensile tests and electron microscopy. Sc and Zr additions do not change the texture of homogenized and cold rolled alloys, but transfer the cube texture of the aged Al–Zn–Mg alloy into -fiber rolling texture. With increasing Sc and Zr additions, the strength significantly increases, and mechanical anisotropy is enhanced. The strength is highest parallel to the rolling direction, whereas it is lowest at a 45° angle to the rolling direction. The higher strength is mainly due to grain boundary strengthening and precipitation strengthening caused by Al₃ScxZr₁₋x nano-particles. The stronger mechanical anisotropy is ascribed to the rolling texture, due to the inhibitory effect of Al₃ScxZr₁₋x on recrystallization. A new model was successfully established to reveal the interrelation between Sc and Zr additions, texture and yield strength anisotropy of Al–Zn–Mg sheets
Impacts of the East Asian monsoon on lower tropospheric ozone over coastal South China
The impact of the East Asian monsoon (EAM) on climatology and interannual variability of
tropospheric ozone (O3) over the coastal South China was investigated by analyzing 11 years
of ozonesonde data over Hong Kong with the aid of Lagrangian dispersion modeling of carbon
monoxide and calculation of an EAM index. It was found that the seasonal cycle of O3 in the
lower troposphere is highly related to the EAM over the study region. Ozone enhancements in
the free troposphere are associated with the monsoon-induced transport of pollutants of
continental anthropogenic and biomass burning origins. Lower tropospheric O3 levels showed
high interannual variability, with an annual averaged amplitude up to 61% of averaged
concentrations in the boundary layer (0–1 km altitudes) and 49% below 3 km altitude. In
spring and autumn, the interannual variability in boundary layer O3 levels was predominately
influenced by the EAM intensity, with high O3 mixing ratios associated with northeasterly
circulation anomalies
Azimuthal asymmetries in lepton-pair production at a fixed-target experiment using the LHC beams (AFTER)
A multi-purpose fixed-target experiment using the proton and lead-ion beams
of the LHC was recently proposed by Brodsky, Fleuret, Hadjidakis and Lansberg,
and here we concentrate our study on some issues related to the spin physics
part of this project (referred to as AFTER). We study the nucleon spin
structure through and processes with a fixed-target experiment using
the LHC proton beams, for the kinematical region with 7 TeV proton beams at the
energy in center-of-mass frame of two nucleons GeV. We calculate
and estimate the azimuthal asymmetries of unpolarized and
dilepton production processes in the Drell--Yan continuum region and at the
-pole. We also calculate the , and
azimuthal asymmetries of and dilepton production
processes with the target proton and deuteron longitudinally or transversally
polarized in the Drell--Yan continuum region and around resonances region.
We conclude that it is feasible to measure these azimuthal asymmetries,
consequently the three-dimensional or transverse momentum dependent parton
distribution functions (3dPDFs or TMDs), at this new AFTER facility.Comment: 15 pages, 40 figures. Version accepted for publication in EPJ
Experimental and Numerical Investigation on Thermal Management of an Outdoor Battery Cabinet
Many forms of electronic equipment such as battery packs and telecom equipment must be stored in harsh outdoor environment. It is essential that these facilities be protected from a wide range of ambient temperatures and solar radiation. Temperature extremes greatly reduce lead-acid based battery performance and shorten battery life. Therefore, it is important to maintain the cabinet temperature within the optimal values between 20oC and 30oC to ensure battery stability and to extend battery lifespan. To this end, cabinet enclosures with proper thermal management have been developed to house such electronic equipment in a highly weather tight manner, especially for battery cabinet.
In this paper, the flow field and temperature distribution inside an outdoor cabinet are studied experimentally and numerically. The battery cabinets house 24 batteries in two configurations namely, two-layer configuration and six-layer configuration respectively. The cabinet walls are maintained at a constant temperature by a refrigeration system. The cabinet’s ability to protect the batteries from an ambient temperature as high as 50oC is studied. An experimental facility is developed to measure the battery surface temperatures and to validate the numerical simulations. The differences between the experimental and computational fluid dynamic (CFD) results are within 5%
Weighted azimuthal asymmetries in a diquark spectator model
We analytically calculate weighted azimuthal asymmetries in semi-inclusive
lepton-nucleon deep-inelastic scattering and Drell-Yan processes, using
transverse-momentum-dependent partonic densities obtained in a diquark
spectator model. We compare the asymmetries with available preliminary
experimental data, in particular for the Collins and the Sivers effect. We make
predictions for other cases of interest in running and planned experiments.Comment: 21 pages, 13 (multiple) figures in eps format, RevTeX
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
Study of J/psi decays to Lambda Lambdabar and Sigma0 Sigma0bar
The branching ratios and Angular distributions for J/psi decays to Lambda
Lambdabar and Sigma0 Sigma0bar are measured using BESII 58 million J/psi.Comment: 11 pages, 5 figure
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