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The statistical analysis and recovery behavior of dislocations in cold-rolled and annealed reactor pressure vessel steels with a thickness reduction of 50% were investigated by using x-ray diffraction and electron backscattered diffraction analysis in this study. A new modified Kubin & Mortensen’s method was proposed to evaluate the geometrically necessary dislocation density, and this method could effectively improve the accuracy of geometrically necessary dislocation evaluation by eliminating the effect of step size and measurement noises. Comparison analysis between modified Williamson-Hall and modified Kubin & Mortensen’s methods was also performed in this study, which shows different recovery behavior of dislocations. The electron backscattered diffraction results show that geometrically necessary dislocation density remained unchangeable after annealing treatment below and at 550°C, and it occurred to decrease above 550°C due to the occurrence of recrystallization. However, dislocations started to migrate and annihilate at 340°C according to x-ray diffraction results. A possible explanation is a difference in the effect of pairwise dislocation annihilation on statistically stored dislocations and geometrically necessary dislocations. [ABSTRACT FROM AUTHOR]

In order to enhance crude oil recovery, the dosages of alkali, surfactant, and polymer in the tertiary flooding are becoming increasingly higher, which makes the emulsion more difficult to demulsify. In this article the application of new organic silicone demulsifiers for the demulsification of produced crude emulsion of alkali-surfactant-polymer (ASP) flooding with higher concentrations of alkali, surfactant, and polymer was investigated. The result indicated that organic silicone demulsifiers whose hydrophile-lipophile balance (HLB) number ranged from 10 to 15 had a satisfactory effect on demulsification. The dewatering efficiency can be improved evidently by adding a demulsifier mixed with DC2 and JG31 whose volume ratio was 4:1. The dewatering efficiency for produced crude emulsion from ASP flooding could exceed 80% at 60°C in which the concentrations of alkali, polymer, and surfactant ranged from 1,200 to 9,000 mg/L, 400 to 1,000 mg/L, and 200 to 800 mg/L, respectively. The simulative industrialized experiment of the ASP flooding produced emulsion was made, the dewatering efficiency was 99.6%, and the oil content of the produced water was less than 100 mg/L. [ABSTRACT FROM AUTHOR]

Abstract  Amorphous Pd40Ni40P20 alloy has potential applications in electronics and catalytic industry. In this paper, amorphous Pd40Ni40P20 films were prepared by electrodeposition. Samples were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and profilometry. Voltammetric curves and potential–time transient indicate the leading role of Pd in the initial growth stage. Based on compositional, morphological, and electrochemical analyses, Pd40Ni40P20 electrodeposition is regarded as Pd-induced PdNiP co-deposition accompanying with hydrogen evolution reactions. [ABSTRACT FROM AUTHOR]

Offsets of molecular line emission peaks from continuum peaks are very common but frequently difficult to explain with a single spherical cloud chemical model. We propose that the spatial projection effects of an irregular three-dimensional (3D) cloud structure can be a solution. This work shows that the idea can be successfully applied to the Planck cold clump G224.4-0.6 by approximating it with four individual spherically symmetric cloud cores whose chemical patterns overlap with each other to produce observable line maps. With the empirical physical structures inferred from the observation data of this clump and a gas-grain chemical model, the four cores can satisfactorily reproduce its 850 μm continuum map and the diverse peak offsets of CCS, HC3N, and N2H+ simultaneously at chemical ages of about 8 × 105 ∼ 3 × 106 yr. The 3D projection effects on chemistry has the potential to explain such asymmetrical distributions of chemicals in many other molecular clouds. [ABSTRACT FROM AUTHOR]

We take advantage of an analytic model of galaxy formation coupled to the merger tree of an N-body simulation to study the roles of environment and stellar mass in the quenching of galaxies. The model has been originally set in order to provide the observed evolution of the stellar mass function as well as reasonable predictions of the star formation rate–stellar mass relation, from high redshift to the present time. We analyze the stellar mass and environmental quenching efficiencies and their dependence on stellar mass, halo mass (taken as a proxy for the environment), and redshift. Our analysis shows that the two quenching efficiencies are dependent on redshift and stellar and halo mass, and that the halo mass is also a good proxy for the environment. The environmental quenching increases with decreasing redshift and is inefficient below log M* ∼ 9.5, reaches the maximum value at log M* ∼ 10.5, and decreases again, becoming poorly efficient at very high stellar mass (log M* ≳ 11.5). Central and satellites galaxies are mass quenched differently: for the former, the quenching efficiency depends very weakly on redshift but strongly on stellar mass; for the latter, it strongly depends on both stellar mass and redshift in the range . According to the most recent observational results, we find that the two quenching efficiencies are not separable: intermediate-mass galaxies, as well as intermediate/massive galaxies in more massive halos, are environmentally quenched faster. At stellar masses lower than log M* ≲ 9.5, both quenching mechanisms become inefficient, independently of the redshift. [ABSTRACT FROM AUTHOR]

To deepen our understanding of the chemical properties of the Planck Galactic Cold Clump (PGCC) G168.72-15.48, we performed observations of nine molecular species, namely, c-C3H, H2CO, HC5N, HC7N, SO, CCH, N2H+, CH3OH, and CH3CCH, toward two dense cores in PGCC G168.72-15.48 using the Tianma Radio Telescope and Purple Mountain Observatory Telescope. We detected c-C3H, H2CO, HC5N, N2H+, CCH, and CH3OH in both G168-H1 and G168-H2 cores, whereas HC7N and CH3CCH were detected only in G168-H1 and SO was detected only in G168-H2. Mapping observations reveal that the CCH, N2H+, CH3OH, and CH3CCH emissions are well coupled with the dust emission in G168-H1. Additionally, N2H+ exhibits an exceptionally weak emission in the denser and more evolved G168-H2 core, which may be attributed to the N2H+ depletion. We suggest that the N2H+ depletion in G168-H2 is dominated by N2 depletion, rather than the destruction by CO. The local thermodynamic equilibrium calculations indicate that the carbon-chain molecules of CCH, HC5N, HC7N, and CH3CCH are more abundant in the younger G168-H1 core. We found that starless core G168-H1 may have the properties of cold dark clouds based on its abundances of carbon-chain molecules. While, the prestellar core G168-H2 exhibits lower carbon-chain molecular abundances than the general cold dark clouds. With our gas-grain astrochemical model calculations, we attribute the observed chemical differences between G168-H1 and G168-H2 to their different gas densities and different evolutionary stages. [ABSTRACT FROM AUTHOR]

Orion KL is one of the prime templates of astrochemical and prebiotic chemical studies. We wish to explore more organic molecules with increasing complexity in this region. In particular, we have searched for one of the most complex organic molecules detected in space so far, ethyl formate (C2H5OCHO). This species is the next step in chemical complexity after the simplest member of esters (methyl formate, CH3OCHO). The mechanisms leading to its formation are still poorly known. We have used high angular resolution (∼1.″5) ALMA observations covering a large bandwidth from 214 to 247 GHz. We have detected 82 unblended lines of C2H5OCHO (49 and 33 of the trans- and gauche-conformers, respectively). The line images showed that C2H5OCHO arises mainly from the compact ridge and the hot core-southwest regions. The derived rotational temperatures and column densities are 122 ± 34 K, (0.9 ± 0.3) × 1016 cm−2 for the hot core-SW, and 103 ± 13 K, (0.6 ± 0.3) × 1016 cm−2 for the compact ridge. The comparison of spatial distribution and abundance ratios with chemically related molecules (methyl formate, ethanol, and formic acid) indicates that C2H5OCHO is likely formed on the surface of dust grains by addition of CH3 to functional-group radicals (CH2OCHO) derived from methyl formate (CH3OCHO). [ABSTRACT FROM AUTHOR]

The pain and risk of infection associated with invasive blood sampling for blood gas measurements necessitate the search for reliable noninvasive techniques. In this work we developed a novel rate-based noninvasive method for a safe and fast assessment of respiratory status. A small sampler was built to collect the gases diffusing out of the skin. It was connected to a CO2 sensor through gas-impermeable tubing. During a measurement, the CO2 initially present in the sampler was first removed by purging it with nitrogen. The gases in the system were then recirculated between the sampler and the CO2 sensor, and the CO2 diffusion rate into the sampler was measured. Because the measurement is based on the initial transcutaneous diffusion rate, reaching mass transfer equilibrium and heating the skin is no longer required, thus, making it much faster and safer than traditional method. A series of designed experiments were performed to analyze the effect of the measurement parameters such as sampler size, measurement location, subject positions, and movement. After the factor analysis tests, the prototype was sent to a level IV NICU for clinical trial. The results show that the measured initial rate of increase in CO2 partial pressure is linearly correlated with the corresponding arterial blood gas measurements. The new approach can be used as a trending tool, making frequent blood sampling unnecessary for respiratory status monitoring. [ABSTRACT FROM AUTHOR]