Shear Behavior of Stud-PBL Composite Shear Connector for Steel-Ceramsite Concrete Composite Structure

Proceedings of the 2021 International Workshop on Modern Science and Technology; September 29, 2021conference pape

1-Phenyl-3-(pyren-1-yl)prop-2-en-1-one

The title compound, C25H16O, was prepared by the condens­ation reaction of pyrene-1-carbaldehyde and acetophenone in ethanol solution at room temperature. The phenyl ring forms a dihedral angle of 39.10 (11)° with the pyrene ring system. In the crystal structure, adjacent pyrene ring systems are linked by aromatic π–π stacking inter­actions, with a perpendicular inter­planar distance of 3.267 (6) Å and a centroid–centroid offset of 2.946 (7) Å

Simulation of the Evolution of the Nanostructure of Crosslinked Silica-Aerogels under Compression

Silica-aerogels are ultra-low-density assemblies of silica nanoparticles, and possess superior acoustic, specific energy absorption and thermal insulation properties. A new class of aerogels encapsulated with polymer is classified as crosslinked silica-aerogels. Manufacturing of such crosslinked silica-aerogel structures, depending on the type and shape of the nanoparticles, the polymer cross-linker and the chemistry in use, yields structures with vastly different morphologies and a wide range of mechanical behavior. With this, it has become necessary to understand the nanostructure / macroscopic properties relationship. Modeling of the aerogel material properties from mesoscale and up approach is needed, which is not considered by the current phenomenological models based on continuum material assumption. Most of the existing simulation methodologies face difficulties mainly due to complex nanostructures, large distortions, and extensive contact. A relatively new numerical method called Material Point Method (MPM) can circumvent these problems. For example, MPM has been used effectively in modeling the microstructural evolution of the bulk metallic glass foam with 70% porosity, where 3D X-Ray microtomography was used first to obtain the representative volume element (RVE) of the closed-cell foam . Due to the particle description of matter, MPM is a very suitable for silica-aerogel simulations. In this regard, an approach based on X-Ray nano-computed tomography (n-CT) will be used to model cross-linked aerogel mesostructure. The voxel information from the 3D tomography will be used to generate material points in MPM. The parallel version (using Structured Adaptive Mesh Refinement Application Infrastructure) of MPM code will be used to simulate the response of the model under compression. In this paper, the MPM is used to model a crosslinked templated silicaaerogel (X-MP4-T045) in compression, and the simulation results are compared with the compressive stress-strain curve obtained experimentally. This work will focus on the deformation mechanisms in crosslinked templated silica-aerogel such as the elastic buckling, compaction and densification, as well as the dependence of mechanical properties on the porosity effect for this crosslinked templated silica-aerogel

Side-chain ionization enables ultrafast intramolecular singlet fission in the azaquinodimethane skeleton

Singlet fission (SF) could significantly alleviate thermalization losses of high-energy photons, thus holding great potential for improving the power conversion efficiency of solar cells. Conventional SF materials require an intricate control of molecular packing motifs in the solid state to achieve efficient multiexciton generation. Small molecule intramolecular singlet fission (iSF) materials have emerged as promising alternatives and show great potential for practical device applications. However, the scope of such iSF materials remains rather limited, necessitating innovative molecular design strategies. Herein, we present how a side-chain ionization strategy leads to an iSF chromophore based on the azaquinodimethane (AQM) ring system. Systematic theoretical and spectroscopic analyses reveal that the direct attachment of electron-withdrawing ionic groups to the conjugated AQM core renders the originally fluorescent AQM nonemissive, leading to ionic AQM (iAQM) derivatives capable of ultrafast iSF to populate triplet-like species. Further fine-tuning of the iAQM skeleton imparts subtle intermolecular interactions that are indispensable for the efficient separation of triplet pairs following iSF in the aggregated state. Our findings offer unprecedented insights into molecular design and triplet exciton dynamics, laying the foundation for the discovery of rare molecular iSF materials

Tris[2-(pyrrol-2-ylmethyl­eneamino)eth­yl]amine

The title compound, C21H27N7, was synthesized by reaction of tris­(2-amino­ethyl)amine and pyrrole-2-carbaldehyde in ethanol at room temperature. The structure is stabilized by intra- and inter­molecular C—H⋯N and N—H⋯N hydrogen-bonding inter­actions

Global disease burden linked to diet high in red meat and colorectal cancer from 1990 to 2019 and its prediction up to 2030

Abstract Numerous studies have already identified an association between excessive consumption of red meat and colorectal cancer (CRC). However, there has been a lack of detailed understanding regarding the disease burden linked to diet high in red meat and CRC. Our objective was to evaluate global, regional, and national mortality rates and disability-adjusted Life years (DALYs) related to this diet. We also considered factors such as sex, age, the socio-demographic index (SDI), and evaluated the cross-national inequalities. Furthermore, we utilized DALYs data from 204 countries and regions to gauge cross-country inequalities of CRC by calculating the slope index of inequality and concentration index as standard indicators of absolute and relative inequalities. Our data was derived from the Global Burden of Disease (GBD) Study 2019. The results show that globally, the ASMR and ASDR related to CRC due to diet high in red meat have decreased, with EAPCs of -0.32% (95% CI -0.37 to -0.28) and -0.18% (95% CI -0.25 to -0.11). Notably, the burden was higher among males and the elderly. The slope index of inequality rose from 22.0 (95% CI 18.1 to 25.9) in 1990 to 32.9 (95% CI 28.3 to 37.5) in 2019 and the concentration index fell from 59.5 (95% CI 46.4 to 72.6) in 1990 to 48.9 (95% CI 34.6 to 63.1) in 2019. We aim to offer evidence-based guidance for developing effective strategies that can mitigate the elevated CRC burden in certain countries. Keywords: colorectal cancer, red meat, Global Burden of Disease, mortality, disability-adjusted life years, health inequality, epidemiolog

Photochemical reaction enabling the engineering of photonic spin-orbit coupling in organic-crystal optical microcavities

The control and active manipulation of spin-orbit coupling (SOC) in photonic systems is fundamental in the development of modern spin optics and topological photonic devices. Here, we demonstrate the control of an artificial Rashba-Dresselhaus (RD) SOC mediated by photochemical reactions in a microcavity filled with an organic single-crystal of photochromic phase-change character. Splitting of the circular polarization components of the optical modes induced by photonic RD SOC is observed experimentally in momentum space. By applying an ultraviolet light beam, we control the spatial molecular orientation through a photochemical reaction and with that we control the energies of the photonic modes. This way we realize a reversible conversion of spin-splitting of the optical modes with different energies, leading to an optically controlled switching between circularly and linearly polarized emission from our device. Our strategy of in situ and reversible engineering of SOC induced by a light field provides a promising approach to actively design and manipulate synthetic gauge fields towards future on-chip integration in photonics and topological photonic devices

Dual orthogonally-polarized lasing assisted by imaginary Fermi arcs in organic microcavities

The polarization control of micro/nano lasers is an important topic in nanophotonics. Up to now, the simultaneous generation of two distinguishable orthogonally-polarized lasing modes from a single organic microlaser remains a critical challenge. Here, we demonstrate simultaneously orthogonally-polarized dual lasing from a microcavity filled with an organic single crystal exhibiting selective strong coupling. We show that the non-Hermiticity due to polarization-dependent losses leads to the formation of real and imaginary Fermi arcs with exceptional points. Simultaneous orthogonally-polarized lasing becomes possible thanks to the eigenstate mixing by the photonic spin-orbit coupling at the imaginary Fermi arcs. Our work provides a novel way to develop linearly-polarized lasers and paves the way for the future fundamental research in topological photonics, non-Hermitian optics, and other fields.Comment: arXiv admin note: text overlap with arXiv:2110.1345