Dynamic Response of Vertical Tank Impacted by Blast Fragments in Chemical Industrial Parks

PresentationThe adjacent vessels may be impacted and/or destroyed by blast fragments in chemical industrial parks or plants, which could lead to the domino effects. Based on the analysis of common parameters of blast fragments including the shape, quantity, mass, and impact velocity, the numerical model of vertical storage tanks impacted by blast fragments was developed with LS- DYNA. Considering deformation of the fragment itself, the law of the dynamic response of vertical tank was described quantitatively. The resultsshowed that there were 3 collisions during the impact process, the maximum plastic deformation occurred at the impact center, the plastic strain was mainly distributed in the range from the impact center to the tank bottom, and there were 4 plastic hinge lines in the deformation region. There was linear relationship between the residual displacement of impact center and the impact velocity of the fragment, and the tank wall had entered plastic deformation stage. With the horizontal impact angle in the range from 15° to 30°, the plastic deformation energy of the tank increased with the horizontal impact angle evidently; with the horizontal impact angle in the range from 30° to 35°, the impact mode of the fragment was changed from penetrating the tank wall to sliding along the tank wall; with the horizontal impact angle in the range from 35° to 60°, the deformation energy of the tank decreased linearly with horizontal impact angle, and the influence of vertical impact angle on the deformation energy of the tank was greatly reduced

Molecular Beam Epitaxy Growth of Superconducting LiFeAs Film on SrTiO3(001) Substrate

The stoichiometric "111" iron-based superconductor, LiFeAs, has attacted great research interest in recent years. For the first time, we have successfully grown LiFeAs thin film by molecular beam epitaxy (MBE) on SrTiO3(001) substrate, and studied the interfacial growth behavior by reflection high energy electron diffraction (RHEED) and low-temperature scanning tunneling microscope (LT-STM). The effects of substrate temperature and Li/Fe flux ratio were investigated. Uniform LiFeAs film as thin as 3 quintuple-layer (QL) is formed. Superconducting gap appears in LiFeAs films thicker than 4 QL at 4.7 K. When the film is thicker than 13 QL, the superconducting gap determined by the distance between coherence peaks is about 7 meV, close to the value of bulk material. The ex situ transport measurement of thick LiFeAs film shows a sharp superconducting transition around 16 K. The upper critical field, Hc2(0)=13.0 T, is estimated from the temperature dependent magnetoresistance. The precise thickness and quality control of LiFeAs film paves the road of growing similar ultrathin iron arsenide films.Comment: 7 pages, 6 figure

Poly[aqua[μ2-1,2-bis­(imidazol-1-yl­methyl)benzene-κ2 N 3:N 3′](μ2-5-bromo­benzene-1,3-dicarboxyl­ato-κ3 O 1,O 1′:O 3)nickel(II)]

In the two-dimensional title coordination polymer, [Ni(C8H3BrO4)(C14H14N4)(H2O)]n, the NiII atom adopts a distorted octa­hedral geometry, being ligated by three O atoms from two different 5-bromo­benzene-1,3-dicarboxyl­ate ligands, two N atoms from two 1,2-bis­(imidazol-1-ylmeth­yl)benzene ligands and one coordinated water mol­ecule. The Ni atoms are bridged by the 5-bromo­benzene-1,3-dicarboxyl­ate ligands, forming chains, which are further linked by 1,2-bis­(imidazol-1-ylmeth­yl)benzene, generating a layer structure parallel to (001)

ImmFusion: Robust mmWave-RGB Fusion for 3D Human Body Reconstruction in All Weather Conditions

3D human reconstruction from RGB images achieves decent results in good weather conditions but degrades dramatically in rough weather. Complementary, mmWave radars have been employed to reconstruct 3D human joints and meshes in rough weather. However, combining RGB and mmWave signals for robust all-weather 3D human reconstruction is still an open challenge, given the sparse nature of mmWave and the vulnerability of RGB images. In this paper, we present ImmFusion, the first mmWave-RGB fusion solution to reconstruct 3D human bodies in all weather conditions robustly. Specifically, our ImmFusion consists of image and point backbones for token feature extraction and a Transformer module for token fusion. The image and point backbones refine global and local features from original data, and the Fusion Transformer Module aims for effective information fusion of two modalities by dynamically selecting informative tokens. Extensive experiments on a large-scale dataset, mmBody, captured in various environments demonstrate that ImmFusion can efficiently utilize the information of two modalities to achieve a robust 3D human body reconstruction in all weather conditions. In addition, our method's accuracy is significantly superior to that of state-of-the-art Transformer-based LiDAR-camera fusion methods

Visualizing the elongated vortices in γ\gamma-Ga nanostrips

We study the magnetic response of superconducting $\gamma$-Ga via low temperature scanning tunneling microscopy and spectroscopy. The magnetic vortex cores rely substantially on the Ga geometry, and exhibit an unexpectedly-large axial elongation with aspect ratio up to 40 in rectangular Ga nano-strips (width $l$ $<$ 100 nm). This is in stark contrast with the isotropic circular vortex core in a larger round-shaped Ga island. We suggest that the unusual elongated vortices in Ga nanostrips originate from geometric confinement effect probably via the strong repulsive interaction between the vortices and Meissner screening currents at the sample edge. Our finding provides novel conceptual insights into the geometrical confinement effect on magnetic vortices and forms the basis for the technological applications of superconductors.Comment: published in Phys. Rev. B as a Rapid Communicatio