Multiple nodal solutions of nonlinear Choquard equations

In this paper, we consider the existence of multiple nodal solutions of the nonlinear Choquard equation \begin{equation*} \ \ \ \ (P)\ \ \ \ \begin{cases} -\Delta u+u=(|x|^{-1}\ast|u|^p)|u|^{p-2}u \ \ \ \text{in}\ \mathbb{R}^3, \ \ \ \ \\ u\in H^1(\mathbb{R}^3),\\ \end{cases} \end{equation*} where $p\in (\frac{5}{2},5)$. We show that for any positive integer $k$, problem $(P)$ has at least a radially symmetrical solution changing sign exactly $k$-times

Research on Random Fatigue Load Model of Highway Bridge by Vehicle Traffic Based on GMM

Highway bridges have often suffered accidents due to fatigue damage. This paper studies the influence of vehicle operating state on the fatigue performance of bridges. Based on GMM method and K-S test in information statistics, this paper proposes an improved Gaussian hybrid modelling method, and studies the various parameters of vehicle operating state on beam bridge fatigue, such as the impact of the damage and its fatigue life assessment. On this basis, the fatigue cumulative damage formula of multi-vehicle upper bridge is proposed. The traffic load of Shandong JiNan-QingDao expressway has been GMMly analysed by GMM. The Gaussian mixture model is used to fit the vehicle load probability function by standard fatigue vehicle model. Based on the expressway, the vehicle fatigue has been established to facilitate the fatigue load and evaluate the fatigue life. Gradually this paper helps to improve the accuracy and convenience of the probability model, which is conducive to the establishment of a scientific and efficient load probability model for road vehicles

Dislocation-Precipitate Interactions in Magnesium-Neodymium Alloys

The dislocation-precipitate interaction in Mg-Nd alloy has been characterized by in situ straining in transmission electron microscopy (TEM). Postmortem study on deformed samples has been conduct on various technique including weak-beam dark field and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Bulk properties data has been collected from the tensile test. In addition to experimental results, supplementary computational molecular dynamic (MD) simulation and first principle calculation provide insight and validation for found mechanisms. The unit dynamic process between extended β1 precipitate and basal dislocation is characterized via viewing dislocation-precipitate interaction at basal plane. Dislocations are observed to glide along precipitate broad facet. A dislocation-theory based analysis suggests that the shape, spacing and orientation (with respect to the glide plane) of β1 precipitates may favor glide of pinned dislocations along interfaces as opposed to the classical mechanism of bowing and looping around the precipitate. The analysis also suggests the dislocation relaxation is the root cause for the interface gliding mechanism. Further in situ straining and postmortem TEM dislocation analysis investigation revealed that basal {a} type dislocations interacted differently with β1 (Mg3Nd) and β’’’ (Mg3-7Nd) precipitates. For β’’’ precipitates, dislocations directly shear the precipitates. For interactions with β1 precipitates, dislocations were observed to by-pass the precipitates and then cross-slip to prismatic planes. The cross-slip associated with β1 precipitates occurred at either the departure or front end of the lenticular shaped phase. Dislocations with screw characteristic are able to overcome β1 precipitate by double cross-slip. The cross-slip mechanism was explored by MD simulations, and found to be similar to the Friedel-Escaig mechanism in pure Mg. The role of cross-slip in a β1-precipitate-dominant microstructure in enhancing ductility is discussed. The cross-slip mechanism introduces dislocation kink receiving strong lattice resistance along propagating direction, which is suspected to prevent following dislocation motion and finally leads to dislocation pile-up. The dislocation pile-up phenomenon was then observed in in situ straining experiment. Analysis of the images from the in situ experiments as well as postmortem TEM of bulk deformed samples reveals that, in the presence of a dislocation pile-up of sufficient intensity, slip is transmitted through the β1 precipitates. This impediment to dislocation motion from planar precipitate facets is analyzed using dislocation theory and density functional theory calculations. It is shown that the β1 precipitate “walls” result in a strong but not impenetrable barrier to slip transmission. The imposed dislocations pile-up effect on β1 precipitates is systematically characterized from tensile and compressive sample. In the tensile samples, contrary to the one single plane shearing as expected from classic precipitate cutting mechanism, several shearing events occur at a series slip plane parallel to each other, resulting in a region of deformation layer. The precipitates are significantly deformed within the layer but still remain connected. MD simulations validate the experiment result and show that deformation gradually spread across the layer, indicating a new mechanism to accommodate imposed displacement from shearing events. In the compressive samples, precipitates are more vulnerable to fragment into small pieces, which is suspected to associate with the buckling effect from c axis compressive stressPHDMaterials Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/153465/1/huzhihua_1.pd

Matrine inhibits hepatocellular carcinoma cell malignancy through the circ_0013290/miR-139-5p/MMP16 pathway

Background. Previous studies have shown the anticancer effect of Matrine on hepatocellular carcinoma (HCC); however, the underlying mechanism is still indistinct. Methods. The expression of circular RNA_0013290 (circ_0013290), microRNA-139-5p (miR-139-5p), matrix metallopeptidase 16 (MMP16), CyclinD1 and N-cadherin was analyzed by quantitative real-time polymerase chain reaction, Western blotting or immuno-histochemistry assay. Cell viability, proliferation, apoptosis, invasion and tube formation were analyzed by cell counting kit-8, 5-Ethynyl-2’-deoxyuridine, flow cytometry analysis, transwell invasion and tube formation assays, respectively. The associations among circ_0013290, miR-139-5p and MMP16 were predicted by starbase online database, and identified by dual-luciferase reporter and RNA pull-down assays. A xenograft mouse model assay was conducted to disclose the effects of circ_0013290 and Matrine on tumor tumorigenesis in vivo. Results. Circ_0013290 and MMP16 expression were significantly upregulated, while miR-139-5p was downregulated in HCC tissues and cells compared with the matched normal liver tissues and cells. Matrine treatment inhibited HCC cell proliferation, invasion and tube formation but induced cell apoptosis, accompanied by the decrease of CyclinD1 and N-cadherin expression; however, these effects were counteracted when circ_0013290 expression was increased. MiR-139-5p depletion or MMP16 introduction relieved Matrine-induced effects in HCC cells. The regulation of circ_0013290 toward HCC cell processes involved MMP16. With respect to the mechanism, circ_0013290 acted as a miR-139-5p sponge, and miR-139-5p targeted MMP16 in HCC cells. Besides, circ_0013290 regulated MMP16 expression through miR-139-5p. Further, circ_0013290 depletion enhanced the inhibitory effects of Matrine on tumor tumorigenesis. Conclusion. Matrine inhibited HCC cell malignancy through the circ_0013290/miR-139-5p/MMP16 pathway, suggesting that Matrine is a potential therapeutic agent for HC

CommonsenseVIS: Visualizing and Understanding Commonsense Reasoning Capabilities of Natural Language Models

Recently, large pretrained language models have achieved compelling performance on commonsense benchmarks. Nevertheless, it is unclear what commonsense knowledge the models learn and whether they solely exploit spurious patterns. Feature attributions are popular explainability techniques that identify important input concepts for model outputs. However, commonsense knowledge tends to be implicit and rarely explicitly presented in inputs. These methods cannot infer models' implicit reasoning over mentioned concepts. We present CommonsenseVIS, a visual explanatory system that utilizes external commonsense knowledge bases to contextualize model behavior for commonsense question-answering. Specifically, we extract relevant commonsense knowledge in inputs as references to align model behavior with human knowledge. Our system features multi-level visualization and interactive model probing and editing for different concepts and their underlying relations. Through a user study, we show that CommonsenseVIS helps NLP experts conduct a systematic and scalable visual analysis of models' relational reasoning over concepts in different situations.Comment: This paper is accepted by IEEE VIS, 2023. To appear in IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG). 14 pages, 11 figure

Numerical Investigations on Wedge Control of Separation of a Missile from an Aircraft

To make the missile safely separate from the internal weapons bay, a wedge flow control device is mounted on the front of the bay to control the variation of flow during the separation. The numerical simulations of missile separation without and with wedge flow control device under different sizes are carried out. The flow fields of different separation processes are obtained and discussed; the aerodynamic parameters and trajectory parameters of missile of different cases are illustrated and compared. Results show that, the wedge flow control device can accelerate the missile separation and has the effect of regulating the angular motion of missile. The influence of the wedge height is stronger than that of its length on the center of gravity motion and angular motion of missile