The resistivity and mechanical properties of Cu-Sn alloys with different compositions were explored by casting, normalising, cold work and subsequent annealing treatment. Results indicated that the ...Cu-Sn alloy had the characteristics of ultrahigh electrical conductivity, when the Sn content was ∼0·5 wt-%. Note that the resistivity of the as cast and annealed Cu-0·5 wt-%Sn alloys is 1·55 and 1·26 μΩ cm respectively.
Inhaled oxygen, although commonly administered to patients with respiratory disease, causes severe lung injury in animals and is associated with poor clinical outcomes in humans. The relationship ...between hyperoxia, lung and gut microbiota, and lung injury is unknown. Here, we show that hyperoxia conferred a selective relative growth advantage on oxygen-tolerant respiratory microbial species (e.g.,
) as demonstrated by an observational study of critically ill patients receiving mechanical ventilation and experiments using neonatal and adult mouse models. During exposure of mice to hyperoxia, both lung and gut bacterial communities were altered, and these communities contributed to oxygen-induced lung injury. Disruption of lung and gut microbiota preceded lung injury, and variation in microbial communities correlated with variation in lung inflammation. Germ-free mice were protected from oxygen-induced lung injury, and systemic antibiotic treatment selectively modulated the severity of oxygen-induced lung injury in conventionally housed animals. These results suggest that inhaled oxygen may alter lung and gut microbial communities and that these communities could contribute to lung injury.
In view of the difficulty in improving the weaving efficiency of the projectile weaving machine based on the traditional technology principle, This research presents the electromagnetic-drive gripper ...weft insertion mechanism, change the existing mechanical pick principle of weft insertion, its goal is to achieve "zero transmission" friction-free high-speed weft insertion, omit complex mechanical transmission mechanism in picking shaft, and breakthrough the bottleneck of the weft insertion rate, wide fabric problem in principle. Based on the theoretical study of electromagnetic projection and electromagnetic levitation, the structural model and motion model of electromagnetic pick and electromagnetic weft are established by comparing the electromagnetic and permanent magnetic model schemes. In order to meet the requirement of electromagnetic levitation, the linear hall sensor is selected and its driving circuit is designed to obtain the real-time height value of the chip shuttle. Through the analysis of the coil response, the advantages and disadvantages of DC-DC regulation and PWM wave regulation are compared, and the high response hardware circuit of DC-DC regulation is designed. MATLAB simulation ensures the feasibility of PID regulation. The feasibility of the scheme was verified by Maxwell electromagnetic picking simulation and electromagnetic filling insertion simulation. The first phase of picking experiment and static filling insertion experiment were carried out. In order to ensure the stability, the double-row soft iron chip shuttle was used, and good experimental results were obtained, which proved the feasibility of electromagnetic suspension weft insertion scheme.
We have used photoemission spectroscopy in order to investigate the electronic states and chemical bonding related to Au induced atomic chains on the Ge(001) surface. Angle-resolved photoemission ...reveals two types of dispersions around hv = 100 eV the Fermi level whose intensities strongly depend on the incident photon energy. Around, the band structure is dominated by an electronlike band of mainly one-dimensional (1D) character, which shows Tomonaga-Luttinger-like power-law behavior in the k-integrated spectral function. In contrast, lower photon energies reveal a metallic holelike dispersion which resembles the Ge bulk structure with its heavy-hole, light-hole, and split-off branches. The Au 4f core-level spectra show two doublets indicating two different Au bonding sites, whereas the Ge 3d core-level shows two surface components and one bulk component.
Prolonged heterogeneous liver enhancement (PHLE) is a rare phenomenon that is similar to the ultrasound findings of portal venous gas. The purpose of this report is to describe the phenomenon of PHLE ...after the injection of the ultrasound contrast agent SonoVue(®).
From 2000 to 2013, 13 patients with PHLE ("cloudy", "wool-like") after bolus injection of SonoVue(®) were observed. The height, weight, and body mass index (BMI) of the patients, and the number of injections were analyzed. In addition, the literature was reviewed.
The phenomenon occurred as early as 2 minutes after bolus contrast administration and lasted up to 5 hours on both B-mode and contrast-specific ultrasound. 8/13 (62 %) patients received two or more boluses. None of the patients experienced SonoVue(®)-related side effects or health problems. The phenomenon was not reproducible in 3 patients who received a second SonoVue(®) injection 24 hours after receiving the first.
This phenomenon is more likely to occur in patients who receive high-dose (or multiple) injections of UCA. It may occur as early as 2 minutes after contrast administration, and therefore, may affect the evaluation of focal liver lesions in the late phase. This phenomenon should not be misdiagnosed as a pathological finding of the liver.
This paper presents numerical simulation of wind field and contaminant dispersion in the flow over a group of buildings by large eddy simulation (LES) with higher accuracy finite volume method (FVM) ...for numerical discretization of governing equation and with immersed boundary method (IBM) at building surfaces. The paper is aimed at proposing a numerical method which can deal with the complex turbulent flow and contaminant dispersion inside a group of buildings. The geometry of the building layout and flow parameters are taken from the wind tunnel experiments by Davidson et al. 1996. Wind tunnel simulations of plume dispersion through groups of obstacles. Atmospheric Environment 30 (22), 3715–3731 so that the feasibility and reliability of the numerical method and code can be examined by comparison between numerical results and experimental measurements with confidence. The flow patterns and contaminant dispersion inside the group of buildings are shown in agreement with the description of Davidson et al. 1996. Wind tunnel simulations of plume dispersion through groups of obstacles. Atmospheric Environment 30 (22), 3715–3731. The numerical prediction of the statistical properties of contaminant dispersion, e.g. the mean concentration distributions, lateral and vertical spreads of the contaminant an so forth, is in good agreement with wind tunnel experiment measurements. The numerical study of this testing case reveals a number of issues which should be considered in application of LES to such complex turbulent flows in environment engineering, e.g. spatial resolution, reasonable subgrid stress model and the turbulent intensity in atmospheric boundary layer.
Computational simulation method was used in two models of calcium carbonate aqueous solution to explore the mechanism of anti-scaling under electrostatic field on the molecular level. The binding ...energy between the surface and ions indicated that the surface (104) was more favorable for the growth of the new crystal, while it was much easier to decompose under field strength 1300 V/m. The diffusion coefficients of Ca2+ and CO32- revealed that the chemical reaction of Ca2+ and CO32- ions in Model-II was much difficult to form calcium carbonate crystal under electrostatic field. The hydration degree of Ca2+ with O atoms from water molecules showed that the electric field could enhance the hydration degree of Ca2+ under certain field length, hence preventing the chemical reaction with CO32- to produce crystal. In short, the scale inhibition effect under electrostatic field in Model-II was much better.
To understand the level of bactericidal antibodies against
and their rate of protection in children aged between 3 and 23 months, in Liuzhou, in 2012.
Convenience sampling was performed in Liujiang, ...Rong'an and Sanjiang Counties from May through August, 2012. The inclusion criteria for 603 subjects were: Children aged between 3 and 23 months; no history of meningococcal meningitis; no vaccination against
serogroup C; more than 30 days from the last vaccination against
serogroup A. Demographic information and immunization history of the subjects were obtained using questionnaires. Venous blood samples (2.0 ml each) were collected and levels of
antibodies determined using a Serum Bactericidal Assay (SBA). The geometric mean titer (GMT) of serum bacterial antibodies was positive when it was greater than or equal to 1∶2 and protective when greater than 1∶8. Chi-square and Fisher's exact tests were used to compare differences in the positive and protective rates of serum antibodies of
serogroup A and
serogroup C,
A model for the size dependence of the Curie temperature Tc of perovskite ferroelectric particles without any free adjustable parameters has been developed. The model predicts that Tc decreases with ...decreasing particle size. The predictions of the model are in agreement with experimental results for PbTiO3 and BaTiO3.
The dry sliding wear of a medium carbon steel with different microstructures was measured under the normal load range of 50-150 N at 400°C by a pin-on-disc high-temperature wear setup. The wear ...behavior and wear mechanism were systematically studied; in particular, the characteristics of extrusive wear and the transition of wear mechanisms were investigated. Under low normal loads, the wear is oxidative type wear. Once the normal load reached a critical value, a mild-to-severe wear transition occurred, and subsequently an extrusive wear prevailed. The mild-to-severe wear transition depended on the microstructure of matrix; the critical normal load of the transition was 112.5 N for tempered sorbite, 125 N for lamellar pearlite, and 137.5 N for tempered martensite and tempered troostite. As oxidative wear prevailed, a thick oxide layer about 20-30 μ m and a plate-like wear debris with regular outline were recognized. However, as the extrusive wear occurred, the wear rate abruptly increased but the friction coefficient was reduced. The extrusive wear predominated due to thermal softening of the matrix and presented a superthin oxide layer (less than 0.5 μ m) and low oxide content on worn surfaces, accompanied by the appearance of ribbon-like wear debris.
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