Spin-dependent Andreev reflection tunneling through a quantum dot with intradot spin-flip scattering

We study Andreev reflection (AR) tunneling through a quantum dot (QD) connected to a ferromagnet and a superconductor, in which the intradot spin-flip interaction is included. By using the nonequibrium-Green-function method, the formula of the linear AR conductance is derived at zero temperature. It is found that competition between the intradot spin-flip scattering and the tunneling coupling to the leads dominantes resonant behaviours of the AR conductance versus the gate voltage.A weak spin-flip scattering leads to a single peak resonance.However, with the spin-flip scattering strength increasing, the AR conductance will develop into a double peak resonannce implying a novel structure in the tunneling spectrum of the AR conductance. Besides, the effect of the spin-dependent tunneling couplings, the matching of Fermi velocity, and the spin polarization of the ferromagnet on the AR conductance is eximined in detail.Comment: 14 pages, 4 figure

Effects of Temperature on Corrosion Behavior of Reinforcements in Simulated Sea-Sand Concrete Pore Solution

The effects of temperature on the chloride-induced corrosion behavior of reinforcing steel in simulated sea-sand concrete pore solution are studied by means of linear polarization resistance. The results show that the Ecorr (corrosion potential) and icorr (corrosion current density) of the reinforcing steels are temperature and/or chloride concentration (CCl )-related parameters. A linear correlation between Ecorr and temperature and a natural logarithmic correlation between icorr and CCl are observed. It is proved that the relationship between the corrosion rate and temperature follows the Arrhenius equation, whereas the activation energy of corrosion reaction increases with the increase of CCl

The Role of Fluid Mechanics in Coronary Atherosclerotic Plaques: An Up-to-Date Review

Most acute coronary syndromes are due to a sudden luminal embolism caused by the rupturing or erosion of atherosclerotic plaques. Prevention and treatment of plaque development have become an effective strategy to reduce mortality and morbidity from coronary heart disease. It is now generally accepted that plaques with thin-cap fibroatheroma (TCFA) are precursors to rupturing and that larger plaques and high-risk plaque features (including low-attenuation plaque, positive remodeling, napkin-ring sign, and spotty calcification) constitute unstable plaque morphologies. However, plaque vulnerability or rupturing is a complex evolutionary process caused by a combination of multiple factors. Using a combination of medicine, engineering mechanics, and computer software, researchers have turned their attention to computational fluid mechanics. The importance of fluid mechanics in pathological states for promoting plaque progression, inducing plaque tendency to vulnerability, or even rupture, as well as the high value of functional evaluation of myocardial ischemia has become a new area of research. This article reviews recent research advances in coronary plaque fluid mechanics, aiming to describe the concept, research implications, current status of clinical studies, and limitations of fluid mechanic’s characteristic parameters: wall shear stress (WSS), axial plaque shear (APS), and fractional flow reserve (FFR). Previously, most computational fluid dynamics were obtained using invasive methods, such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT). In recent years, the image quality and spatial resolution of coronary computed tomography angiography (CCTA) have greatly improved, making it possible to compute fluid dynamics by noninvasive methods. In the future, the combination of CCTA-based anatomical stenosis, plaque high-risk features, and fluid mechanics can further improve the prediction of plaque development, vulnerability, and risk of rupturing, as well as enabling noninvasive means to assess the degree of myocardial ischemia, thereby providing an important aid to guide clinical decision-making and optimize treatment

Degradation of Lignocellulosic Components in Un-pretreated Vinegar Residue Using an Artificially Constructed Fungal Consortium

The objective of this work was to degrade lignocellulosic components in un-pretreated vinegar residue (VR) using a fungal consortium. Consortium-29, consisting of P. chrysosporium, T. koningii, A. niger, and A. ficuum NTG-23, was constructed using orthogonal design combined with two-way interaction analysis. After seven days of cultivation, the reducing sugar yield reached 35.57 mg per gram of dry substrate (gds-1), which was 108.01% higher than the control (17.10 mg gds-1). Additionally, the xylanase and CMCase activity reached 439.07 U gds-1 and 8.15 U gds-1, which were 432.08% and 243.88% higher than that of pure cultures of A. niger (82.52 U gds-1) and P. chrysosporium (2.37 U gds-1), respectively. The cellulose, hemicellulose, and lignin contents decreased by 17.11%, 68.61%, and 14.44%, respectively, compared with that of the raw VR. The optimal fermentation conditions of consortium-29 were as follows: incubation temperature 25 °C, initial pH 6, initial moisture content 70%, inoculum size 1 x 10^6 spores/mL, incubation time 5 days, urea/VR 1%, and MnSO4 . H2O/VR 0.03%. This study suggests that consortium-29 is an efficient fungal consortium for un-pretreated VR degradation and has a potential application in lignocellulosic waste utilization with a low cost of operation