Selective laser melting (SLM) of pure molybdenum encounters all the difficulties SLM metals due to its intrinsic properties (high point, high ductile-to-brittle transition temperature and surface tension). In this work, we studied influence key factors such as powder morphology processing parameters on fabricated molybdenum. Pure with a relative density 99.1% was by using optimized parameters. The formation mechanisms for densification behavior crack growth behaviors are systematically...

Particle concentration is an important parameter for describing the state of gas–solid two-phase flow. This study compares performance three methods, namely, Back-Propagation Neural Networks (BPNNs), Recurrent (RNNs), and Long Short-Term Memory (LSTM), in handling flow data. The experiment utilized seven parameters, including temperature, humidity, upstream downstream sensor signals, delay, pressure difference, particle concentration, as dataset. evaluation metrics, such prediction accuracy,...

The mechanical properties of interfacial transition zones (ITZs) have traditionally been simplified by reducing the stiffness cement in previous simulation methods.A novel approach based on discrete element method (DEM) has developed for modeling concrete.This new efficiently simulates meso-structure ITZs, accurately capturing their heterogeneous properties.Validation against established uniaxial compression experiments confirms precision this model.The proposed model can process damage...

We use a plasma-activated direct bonding process at room temperature to form heterostructures between GaAs and traditional Si substrates. The intermediate layer is not required the interface. surface activation mainly carried out through inductively coupled Ar plasma for 60 s with bombardment. After activation, oxide activity on substrate surfaces enhanced generation of defect states inhibited. By using this process, void-free robust GaAs/Si heterointerface can be realized. Additionally,...

Abstract High-quality bonding of 4-inch GaAs and Si is achieved using plasma-activated technology. The influence Ar plasma activation on surface morphology discussed. When the annealing temperature 300 ℃, strength reaches a maximum 6.2 MPa. In addition, thermal stress model for GaAs/Si wafers established based finite element analysis to obtain distribution equivalent deformation variables at different temperatures. shape variation wafer directly proportional temperature. At an 400 protrusion...

Compared with the traditional cleaning technology, laser cleaning, as a new type of industrial has advantages high rate, green pollution-free and low cost. So is widely used in fields paint removal. This paper analyzes that mechanism removal heat transfer process layer substrate, also determines parameters affect The from steel substrate fiber frequency adjustable 20 to 500kHz at 1064nm reported, researching impact energy density,scanning speed line width on effect. results show that, 100μm...

Optical waveguides play an important role in the fields of optical communications and sensing. As waveguide substrate materials, yttrium aluminum garnet (YAG) crystals have a high refractive index, thermal conductivity, quality, good chemical stability. However, YAG are difficult to fabricate since they chemically inactive Mohs hardness 8.5. This article has proposed method rapidly preparing microhole arrays on using femtosecond laser single-pulse Bessel beam combined with wet etching...

The cigarette filter is an essential component of modern cigarettes and studying the flow distribution within great significance in reducing harm optimizing smoking sensations. As object numerical simulation research, a three-dimensional model was accurately constructed through micro-CT reverse engineering, achieving scanning accuracy 4.05 μm. An overall porous media established to characterize pressure inside filter. Based on reconstruction, local cavity-filtered created by extracting 1/36...

High-aspect-ratio microholes, the fundamental building blocks for microfluidics, optical waveguides, and other devices, find wide applications in aerospace, biomedical, photonics fields. Yttrium aluminum garnet (YAG) crystals are commonly used devices due to their low stress, hardness, excellent chemical stability. Therefore, finding efficient fabrication methods produce high-quality microholes within YAG is crucial. The Bessel beam, characterized by a uniform energy distribution along its...

Signal beam combiners play a pivotal role in enhancing the output power of fiber lasers, which have wide-ranging applications from industrial processing to medical and military uses. This paper explores influence twist angle non-uniform symmetric arrangement on performance 19 × 1 signal combiners. A simulation model was developed analyze impact these parameters under adiabatic tapering conditions principle brightness conservation. The allowed for systematic investigation how varying angles...

Low tracking accuracy of tracker, wind induced vibration structure and lens deformation by temperature lead to non-vertical incident irradiation the Fresnel lens, which necessitates a secondary concentrator in actual engineering application concentrating photovoltaic module. This paper adds focusable microprism between solar cells order improve optical efficiency. The 3D model is established SOLIDWORDS main parameters are optimized using ZEMAX. Results show that combination achieves higher...

The thermally activated blistering and exfoliation of GaAs wafers SiO2/Si3N4/GaAs after H+ He+ implantation is systematically investigated. Surface morphologies microscopic defects are detected analyzed by various measurements, such as optical microscopy (OM), atomic force (AFM), transmission electron (TEM). Blistering obtained on the surfaces either exclusive 5 × 1016 He+/cm2 alone or co-implantation 0.5 4 H+/cm2. Our experimental results show that layer occurred when concentration was...

For improving the accuracy and applicability of laser diode-position sensitive detector (LD-PSD) system, a model roughness reflectance measured surface is established. Combining this with light intensity response PSD space radiation model, we derived relationship between standard deviation (σ), (ρ) center-of-gravity (Χ0). This shows that Χ0 disturbed by σ or ρ only if changes within spot. We conducted simulation experiment to test relationship. The results showed good consistency theory,...

The room-temperature (RT) bonding mechanisms of GaAs/SiO 2 /Si and GaAs/Si heterointerfaces fabricated by surface-activated (SAB) are investigated using a focused ion beam (FIB) system, cross-sectional scanning transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDX) acoustic (SAM). According to the element distribution detected TEM EDX, it is found that an intermixing process occurs among different atoms at heterointerface during RT following surface-activation...