Research on the Mechanical and Thermal Properties of Carbon-Fiber-Reinforced Rubber Based on a Finite Element Simulation.

The comprehensive performance of rubber products could be significantly improved by the addition of functional fillers. To improve research efficiency and decrease the experimental cost, the mechanical and thermal properties of carbon-fiber-reinforced rubber were investigated using finite element simulations and theoretical modeling. The simplified micromechanical model was constructed through the repeatable unit cell with periodic boundary conditions, and the corresponding theoretical models were built based on the rule of mixture (ROM), which can be treated as the mutual verification.

The Toxoplasma Effector GRA4 Hijacks Host TBK1 to Oppositely Regulate Anti-T. Gondii Immunity and Tumor Immunotherapy.

Toxoplasma gondii (T. gondii)-associated polymorphic effector proteins are crucial in parasite development and regulating host anti-T. gondii immune responses.

Analysis of Influencing Factors for Stackable and Expandable Acoustic Metamaterial with Multiple Tortuous Channels.

To reduce the noise generated by large mechanical equipment, a stackable and expandable acoustic metamaterial with multiple tortuous channels (SEAM-MTCs) was developed in this study. The proposed SEAM-MTCs consisted of odd panels, even panels, chambers, and a final closing plate, and these component parts could be fabricated separately and then assembled. The influencing factors, including the number of layers , the thickness of panel , the size of square aperture , and the depth of chamber were investigated using acoustic finite element simulation.

A Novel Trajectory Feature-Boosting Network for Trajectory Prediction.

Trajectory prediction is an essential task in many applications, including autonomous driving, robotics, and surveillance systems. In this paper, we propose a novel trajectory prediction network, called TFBNet (trajectory feature-boosting network), that utilizes trajectory feature boosting to enhance prediction accuracy. TFBNet operates by mapping the original trajectory data to a high-dimensional space, analyzing the change rules of the trajectory in this space, and finally aggregating the trajectory goals to generate the final trajectory.

Effects of Aperture Shape on Absorption Property of Acoustic Metamaterial of Parallel-Connection Helmholtz Resonator.

A Helmholtz resonator (HR) with an embedded aperture is an effective acoustic metamaterial for noise reduction in the low-frequency range. Its sound absorption property is significantly affected by the aperture shape. Sound absorption properties of HRs with the embedded aperture for various tangent sectional shapes were studied by a two-dimensional acoustic finite element simulation.

Research on the Sound Insulation Performance of Composite Rubber Reinforced with Hollow Glass Microsphere Based on Acoustic Finite Element Simulation.

The composite rubber reinforced with hollow glass microsphere (HGM) was a promising composite material for noise reduction, and its sound insulation mechanism was studied based on an acoustic finite element simulation to gain the appropriate parameter with certain constraint conditions. The built simulation model included the air domain, polymer domain and inorganic particles domain. The sound insulation mechanism of the composite material was investigated through distributions of the sound pressure and sound pressure level.

Adjustable Sound Absorber of Multiple Parallel-Connection Helmholtz Resonators with Tunable Apertures Prepared by Low-Force Stereolithography of Photopolymer Resin.

The variable noise spectrum for many actual application scenarios requires a sound absorber to adapt to this variation. An adjustable sound absorber of multiple parallel-connection Helmholtz resonators with tunable apertures (TA-MPCHRs) is prepared by the low-force stereolithography of photopolymer resin, which aims to improve the applicability of the proposed sound absorber for noise with various frequency ranges. The proposed TA-MPCHR metamaterial contains five metamaterial cells.

Experimental and Numerical Study of Static Behavior of Precast Segmental Hollow Bridge Piers.

To investigate the static performance of precast segmental hollow piers, two precast segmental hollow pier specimens were designed for static loading tests on the top of piers. The finite element model of precast segmental hollow piers was established by the finite element software Abaqus and verified based on the test results. Based on the experimental and finite element models, three optimal design solutions were proposed, and the calculation results of each solution were analyzed.

Investigation and Optimization of the Impact of Printing Orientation on Mechanical Properties of Resin Sample in the Low-Force Stereolithography Additive Manufacturing.

The mechanical properties of resin samples in low-force stereolithography additive manufacturing were affected by the printing orientation, and were investigated and optimized to achieve excellent single or comprehensive tensile strength, compressive strength, and flexural modulus. The resin samples were fabricated using a Form3 3D printer based on light curing technology according to the corresponding national standards, and they were detected using a universal testing machine to test their mechanical properties. The influence of the printing orientation was represented by the rotation angle of the resin samples relative to the -axis, -axis and -axis, and the parameters was selected in the range 0°-90° with an interval of 30°.

Optimal Design of Acoustic Metamaterial of Multiple Parallel Hexagonal Helmholtz Resonators by Combination of Finite Element Simulation and Cuckoo Search Algorithm.

To achieve the broadband sound absorption at low frequencies within a limited space, an optimal design of joint simulation method incorporating the finite element simulation and cuckoo search algorithm was proposed. An acoustic metamaterial of multiple parallel hexagonal Helmholtz resonators with sub-wavelength dimensions was designed and optimized in this research. First, the initial geometric parameters of the investigated acoustic metamaterials were confirmed according to the actual noise reduction requirements to reduce the optimization burden and improve the optimization efficiency.

An improved graph convolutional network with feature and temporal attention for multivariate water quality prediction.

The analysis and prediction of water quality are of great significance to water quality management and pollution control. In general, current water quality prediction methods are often aimed at single indicator, while the prediction effect is not ideal for multivariate water quality data. At the same time, there may be some correlations between multiple indicators which the conventional prediction models cannot capture.

Development of Adjustable Parallel Helmholtz Acoustic Metamaterial for Broad Low-Frequency Sound Absorption Band.

For the common difficulties of noise control in a low frequency region, an adjustable parallel Helmholtz acoustic metamaterial (APH-AM) was developed to gain broad sound absorption band by introducing multiple resonant chambers to enlarge the absorption bandwidth and tuning length of rear cavity for each chamber. Based on the coupling analysis of double resonators, the generation mechanism of broad sound absorption by adjusting the structural parameters was analyzed, which provided a foundation for the development of APH-AM with tunable chambers. Different from other optimization designs by theoretical modeling or finite element simulation, the adjustment of sound absorption performance for the proposed APH-AM could be directly conducted in transfer function tube measurement by changing the length of rear cavity for each chamber.

Acoustic Metamaterials for Low-Frequency Noise Reduction Based on Parallel Connection of Multiple Spiral Chambers.

Acoustic metamaterials based on Helmholtz resonance have perfect sound absorption characteristics with the subwavelength size, but the absorption bandwidth is narrow, which limits the practical applications for noise control with broadband. On the basis of the Fabry-Perot resonance principle, a novel sound absorber of the acoustic metamaterial by parallel connection of the multiple spiral chambers (abbreviated as MSC-AM) is proposed and investigated in this research. Through the theoretical modeling, finite element simulation, sample preparation and experimental validation, the effectiveness and practicability of the MSC-AM are verified.

Development and Optimization of Broadband Acoustic Metamaterial Absorber Based on Parallel-Connection Square Helmholtz Resonators.

An acoustic metamaterial absorber of parallel-connection square Helmholtz resonators is proposed in this study, and its sound absorption coefficients are optimized to reduce the noise for the given conditions in the factory. A two-dimensional equivalent simulation model is built to obtain the initial value of parameters and a three-dimensional finite element model is constructed to simulate the sound absorption performance of the metamaterial cell, which aims to improve the research efficiency. The optimal parameters of metamaterial cells are obtained through the particle swarm optimization algorithm, and its effectiveness and accuracy are validated through preparing the experimental sample using 3D printing and measuring the sound absorption coefficient by the standing wave tube detection.

Protective effects and molecular mechanisms of polypeptide k on Schwann cells.

Background: polypeptide k (ABPPk) is an active ingredient used in traditional Chinese medicine separated from polypeptides. So far, the role of ABPPk in peripheral nerve protection has not been comprehensively studied.

Methods: In this study, primary Schwann cells exposed to serum deprivation were treated with ABPPk or nerve growth factor (NGF) .

Polypeptide Protects Schwann Cells From Apoptosis in Hydrogen Peroxide-Induced Oxidative Stress.

ABPPk, the active ingredient separated from polypeptides, is a traditional Chinese medicine with multiple pharmaceutical properties. In this study, we investigated the molecular mechanisms of ABPPk in protecting Schwann cells (SCs) from HO-induced cell apoptosis. The viability of SCs pretreated with ABPPk was elevated significantly by MTT assay estimation.

miR-3075 Inhibited the Migration of Schwann Cells by Targeting Cntn2.

Peripheral nerve injury is a complex biological process that involves the expression changes of various coding and non-coding RNAs. Previously, a number of novel miRNAs that were dysregulated in rat sciatic nerve stumps after peripheral nerve injury were identified and functionally annotated by Solexa sequencing. In the current study, we studied one of these identified novel miRNAs, miR-3075, in depth.

Fabrication of continuous phase plates with small structures based on recursive frequency filtered ion beam figuring.

Large surface gradient and extensive mid-to-high spatial frequency in continuous phase plates (CPPs) with small structures make it difficult to achieve high-precision fabrication. An ion beam figuring (IBF) technology to fabricate CPPs with such characteristics is proposed in this paper. In order to imprint CPP microstructures with smaller spatial periods even down to 1mm in shorter time, we present a multi-pass IBF approach with different ion beam sizes based on the frequency filtering method.

Surface evaluation and evolution during hydrodynamic effect polishing for quartz glass.

Hydrodynamic effect polishing (HEP), a noncontact machining process, can realize the processed surface roughness as small as atomic level. To investigate the subsurface structure, the HEP processed quartz glass surface was etched by the hydrofluoric acid solution. It has been proved that HEP is a polishing method with the ability to process the surface with atomic-level flatness and damage-free surface/subsurface.

Detection of subsurface trace impurity in polished fused silica with biological method.

Subsurface damage (SSD), especially photoactive impurities, degrades the performance of high energy optics by reduction in the laser induced damage threshold. As the polishing defects are trace content and lie beneath the surface, they are difficult to detect. We herein present a biological method to measure impurities on polished fused silica, based on the intense inhibiting ability about trace level of ceria on enzyme activity.

Efficient fabrication of ultrasmooth and defect-free quartz glass surface by hydrodynamic effect polishing combined with ion beam figuring.

Material removal rate has greatly relied on the distribution of shear stress and dynamic pressure on the workpiece surface in hydrodynamic effect polishing (HEP). Fluid dynamic simulation results demonstrate that the higher rotation speed and smaller clearance will cause the larger material removal rate. Molecular dynamic (MD) calculations show the bonding energy of Si-O in the silicon-oxide nanoparticle is stronger than that in the quartz glass, and therefore the atoms can be dragged away from the quartz glass surface by the adsorbed silicon-oxide nanoparticle.

Material removal mode affected by the particle size in fluid jet polishing.

As a newly developed ultrasmooth polishing technique, fluid jet polishing (FJP) has been widely used for optical glass polishing. The size of the particle in the polishing slurry has a great influence on the material removal rate and quality of the processed surface. The material removal mode affected by the particle size is investigated in detail.

Ultrasmooth surface polishing based on the hydrodynamic effect.

This study will examine the feasibility of applying the hydrodynamic effect to ultrasmooth surface polishing. Differing from conventional pad polishing, hydrodynamic effect polishing is noncontact, as the polishing wheel is floated on the workpiece under the hydrodynamic effect. The material removal mechanism and the removal contour are analyzed in detail.