Suppression of epitaxial thin film growth by mixing

We consider following fourth-order parabolic equation with gradient nonlinearity on the two-dimensional torus with and without advection of an incompressible vector field in the case $2<p<3$: \begin{equation*} \partial_t u + (-\Delta)^2 u = -\nabla\cdot(|\nabla u|^{p-2}\nabla u). \end{equation*} The study of this form of equations arises from mathematical models that simulate the epitaxial growth of the thin film. We prove the local existence of mild solutions for any initial data lies in $L^2$ in both cases. Our main result is: in the advective case, if the imposed advection is sufficiently mixing, then the global existence of solution can be proved, and the solution will converge exponentially to a homogeneous mixed state. While in the absence of advection, there exist initial data in $H^2\cap W^{1,\infty}$ such that the solution will blow up in finite time.Comment: 33 page

Dissipation enhancement for a degenerated parabolic equation

In this paper, we quantitatively consider the enhanced-dissipation effect of the advection term to the parabolic $p$-Laplacian equations. More precisely, we show the mixing property of flow for the passive scalar enhances the dissipation process of the $p$-Laplacian in the sense of $L^2$ decay, that is, the $L^2$ decay can be arbitrarily fast. The main ingredient of our argument is to understand the underlying iteration structure inherited from the parabolic $p$-Laplacian equations. This extends the dissipation enhancement result of the advection diffusion equation by Yuanyuan Feng and Gautam Iyer into a non-linear setting.Comment: 22 page

Robust Outlier Detection Method Based on Local Entropy and Global Density

By now, most outlier-detection algorithms struggle to accurately detect both point anomalies and cluster anomalies simultaneously. Furthermore, a few K-nearest-neighbor-based anomaly-detection methods exhibit excellent performance on many datasets, but their sensitivity to the value of K is a critical issue that needs to be addressed. To address these challenges, we propose a novel robust anomaly detection method, called Entropy Density Ratio Outlier Detection (EDROD). This method incorporates the probability density of each sample as the global feature, and the local entropy around each sample as the local feature, to obtain a comprehensive indicator of abnormality for each sample, which is called Entropy Density Ratio (EDR) for short in this paper. By comparing several competing anomaly detection methods on both synthetic and real-world datasets, it is found that the EDROD method can detect both point anomalies and cluster anomalies simultaneously with accurate performance. In addition, it is also found that the EDROD method exhibits strong robustness to the number of selected neighboring samples, the dimension of samples in the dataset, and the size of the dataset. Therefore, the proposed EDROD method can be applied to a variety of real-world datasets to detect anomalies with accurate and robust performances

Upregulation of Heme Oxygenase-1 Endues Immature Dendritic Cells With More Potent and Durable Immunoregulatory Properties and Promotes Engraftment in a Stringent Mouse Cardiac Allotransplant Model

Heme oxygenase-1 (HO-1) is critical for the ability of immature dendritic cells (imDCs) to suppress T-cell responses. Induction of high HO-1 expression may markedly improve the tolerogenic capacity of imDCs. Here, we generated bone marrow-derived DCs (BMDCs) from BALB/c mice with low doses of GM-CSF and IL-4. The adherent BMDCs were obtained as imDCs. Upregulation of HO-1 in imDCs (HO-1hi-imDCs) was achieved by cobalt protoporphyrin treatment. HO-1hi-imDCs proved to be more maturation-resistant than conventional imDCs, with an enhanced ability to inhibit allogeneic T-cell proliferation stimulated by anti-CD3/CD28 antibodies. When donor-derived DC adoptive transfer was performed in a stringent mouse cardiac allotransplant model, the extent of graft prolongation observed with HO-1hi imDCs was superior to that obtained with conventional imDCs. T-cell activation and proliferation in cardiac allograft recipients was more strongly suppressed in the HO-1hi imDC transfusion group than that in the untreated imDC group. Furthermore, donor HO-1hi imDCs were able to maintain a status of high HO-1 expression and survived longer in the recipient spleens than did untreated imDCs after adoptive transfer. In vitro-generated HO-1hi imDCs had an enhanced tolerogenic capacity to modulate alloimmune responses both in vitro and in vivo, and thus may offer a novel antigen-specific and cost-effective strategy to induce transplant tolerance

Constitutive Models for the Strain Strengthening of Austenitic Stainless Steels at Cryogenic Temperatures with a Literature Review

Austenitic stainless steels are widely used in cryogenic pressure vessels, liquefied natural gas pipelines, and offshore transportation liquefied petroleum gas storage tanks due to their excellent mechanical properties at cryogenic temperatures. To meet the lightweight and economical requirements, pre-strain of austenitic stainless steels was conducted to improve the strength at cryogenic temperatures. The essence of being strengthened by strain (strain strengthening) and the phase-transformation mechanism of austenitic stainless steels at cryogenic temperatures are reviewed in this work. The mechanical properties and microstructure evolution of austenitic stainless steels under different temperatures, types, and strain rates are compared. The phase-transformation mechanism of austenitic stainless steels during strain at cryogenic temperatures and its influence on strength and microstructure evolution are summarized. The constitutive models of strain strengthening at cryogenic temperatures were set to calculate the volume fraction of strain-induced martensite and to predict the mechanical properties of austenitic stainless steels

Study on Expansion Rate of Steel Slag Cement-Stabilized Macadam Based on BP Neural Network

The physicochemical properties of steel slag were investigated using SEM and IR, and it was found that free calcium oxide and free magnesium oxide in steel slag produce calcium hydroxide when in contact with water, leading to volume expansion. Thus, the expansion rate of steel slag itself was first investigated, and it was found that the volume expansion of steel slag was more obvious in seven days after water immersion. Then, the cement dosages of 5% and 6% of the steel slag expansion rate and cement-stabilized gravel volume changes between the intrinsic link were further explored after the study found that the cement bonding effect can be partially inhibited due to the volume of expansion caused by the steel slag, so it can be seen that increasing the dosage of cement can reduce the volume expansion of steel slag cement-stabilized gravel with the same dosage of steel slag. Finally, a prediction model of the expansion rate of steel slag cement-stabilized gravel based on the BP (back propagation) neural network was established, which was verified to be a reliable basis for predicting the expansion rate of steel slag cement-stabilized aggregates and improving the accuracy of the proportioning design

Experimental Research on Seismic Behavior of Seismic-Damaged Double-Deck Viaduct Frame Pier Strengthened with CFRP and Enveloped Steel

This paper investigates the seismic behavior of a seismic-damaged double-deck viaduct frame pier (DVFP) strengthened with CFRP and enveloped steel, four strengthened DVFP specimens with different degrees of initial damage were tested under quasi-static cyclic loading. Based on the test results, the hysteretic behavior, the stiffness and strength degradation, crack propagation, and failure mechanism were firstly analyzed. Then, the damage indexes of the tested specimens were calculated with different models to evaluate the seismic strengthening performance. Results of this study show that CFRP and enveloped steel strengthening could effectively improve the strength and ductility of pre-damaged DVFPs. The ultimate load, the failure displacement and the displacement ductility of the moderately damaged specimen after being strengthened were found to increase by 120.74%, 35% and 32.33%, respectively. For the severely damaged specimens with CFRP and enveloped steel strengthening, the figures were 105.36%, 25.98% and 31.41%, respectively. The research results can provide reference for the hybrid strengthening application of seismic-damaged DVFP

Enhancing thermal rectification in graphene-carbon nanotube junctions by tuning the chirality of pillar

This letter investigates thermal rectification (TR) in graphene-carbon nanotube (GN-CNT) junctions formed by SWCNT(12, 12) connected with a single-layer graphene nanosheet (GN-SWCNT(12, 12)). It is found that the TR ratio of GN-SWCNT junction can be enhanced dramatically by tuning the chirality of the pillar. TR ratio of the GN-SWCNT(12, 12) junction can respectively reach up to 1487% and 2586.4% at temperatures of 300 K and 200 K $(\vert \Delta \vert =0.5)$ , much higher than those previously reported for the pillared graphene and GN-CNT junctions. The influences of the geometric parameters on the thermal rectification are discussed. The results could offer useful guidelines to the design and performance improvement of the GN-CNT–based thermal rectifier

HinPhish: An Effective Phishing Detection Approach Based on Heterogeneous Information Networks

Internet users have suffered from phishing attacks for a long time. Attackers deceive users through malicious constructed phishing websites to steal sensitive information, such as bank account numbers, website usernames, and passwords. In recent years, many phishing detection solutions have been proposed, which mainly leverage whitelists or blacklists, website content, or side channel-based techniques. However, with the continuous improvement of phishing technology, current methods have difficulty in achieving effective detection. Hence, in this paper, we propose an effective phishing website detection approach, which we call HinPhish. HinPhish extracts various link relationships from webpages and uses domains and resource objects to construct a heterogeneous information network. HinPhish applies a modified algorithm to leverage the characteristics of different link types in order to calculate the phish-score of the target domain on the webpage. Moreover, HinPhish not only improves the accuracy of detection, but also can increase the phishing cost for attackers. Extensive experimental results demonstrate that HinPhish can achieve an accuracy of 0.9856 and F1-score of 0.9858

Enhanced Photocatalytic Property of Cu Doped Sodium Niobate

We investigate the photocatalytic activity of Cu doped NaNbO3 powder sample prepared by the modified polymer complex method. The photocatalytic activity of hydrogen evolution from methanol aqueous solution was improved by Cu 2.6 at% doping. The photocatalytic degradation of rhodamine B (RhB) under visible light irradiation was enhanced in comparison with pristine NaNbO3. Cu introduction improved the adsorption property of NaNbO3, judging from the Fourier transform infrared spectra. Moreover, the ultraviolet light excitation in Cu doped sample would accelerate the mineralized process