We demonstrate an approach of long-term frequency stabilization a single-loop optoelectronic oscillator (OEO) with phase-locked loop (PLL). The OEO is locked to highly stable microwave reference via PLL circuit PID regulator. With this approach, we obtained 3.035-GHz signal phase noise -65 dBC/Hz at 10-Hz offset frequency, and the stability has reached 6.98 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-14</sup> average time 1000 s. These...

Abstract The mechanical, rheological, and morphological properties of polystyrene (PS)/lignin blends over a wide range lignin content (0–80 wt%) have been studied in this work. PS/lignin were compounded an internal batch mixer with without the addition linear triblock copolymer based on styrene, ethylene, butylene (SEBS). A analysis was carried out by scanning electron microscopy to determine state dispersion interfacial adhesion between particles PS matrix. It found that flexural torsion...

Abstract The hemp fiber/polyethylene (PE) composites were prepared by varying the fiber shape (hemp flour and from thermomechanical refining), coupling agent (maleic anhydride grafted copolymerized onto PE), loading method (during treating process in refiner compositing twin screw extruder), (twin extruding batch mixing). paper firstly measured moisture absorption properties of treated fibers. introduction during decreased effectively uptake. Then, water mechanical investigated on hemp/PE...

We proposed and demonstrated a tunable injection-locked laser, which can be locked in wide range. It also used cascaded injection locking lasers to decrease the influence of temperature drift. Based on this technology, photonic scanning receiver is implement wide-range microwave frequency measurement. The applies optical simplify channelization. In experiment, measure weak signals within 16.5 GHz.

In the era of artificial intelligence, there has been a rise in novel computing methods due to increased demand for rapid and effective data processing. It is great significance develop memristor devices capable emulating computational neural network brain, especially realm intelligence applications. this work, based on NiAl-layered double hydroxides presented with excellent electrical performance, including analog resistive conversion characteristics effect multi-level conductivity...

We demonstrate the implementation of a Rb87 chip-scale atomic clock (CSAC) that has improved long-term stability. A simple method reducing frequency drift in CSAC is proposed. As well as well-known effect light intensity on frequency, our analysis shows due to laser detuning (LFD) variation originates from asymmetry coherent fields, and thus, we propose actively compensate by using variations LFD. performed experiments obtain precise sensitivities LFD, was reduced 7.1×10−11/day 6.9×10−13/day...

Optical spike-timing-dependent plasticity (STDP) synapses form the basis of learning in photonic neuromorphic system. In biological neural systems, STDP generally have multiplicative boundary mechanisms, and can be modulated by a third factor such as dopamine. Analogously, we introduce into optical STDP: The current-injection semiconductor amplifiers modified an adaptive way according to local or global feedback signals. one is present synaptic weight, which elicits weight-dependent STDP,...

Abstract The density and morphology of closed‐cell high‐density foams were investigated with four different molecular weights polyethylene (HDPE). characterization via rheological methods was used to determine its influence on foam morphology. We found that foaming grade decreased increasing weight increased blowing agent content. average cell size also a strong function Increasing both the amount size. Cell for our lowest HDPE but others. weight. © 2003 Wiley Periodicals, Inc. J Appl Polym...

Abstract Wood–polymer composites (WPC) were prepared by impregnation of polymeric monomers in wood and situ polymerization. Three chemicals chosen for this study: methyl methacrylate (MMA), hydroxyethylene (HEMA), ethylene glycol dimethacrylate (EGDMA). The effects their combinations on moisture adsorption ( M ), anti–moisture efficiency (AME), liquid water uptake D repellency (WRE), longitudinal, radial, tangential, volumetric swelling properties S ) after soaking, antiswelling (ASE)...

Abstract This study investigated the effects of raw fiber materials, content, and coupling agent (CA) content on mixing torque, rheological properties, crystallization behavior wood plastic composites (WPC). WPCs were prepared through melt molding processes. adopted a response surface strategy 20 run optimal design for three factors including type, CA content. Wood type or characteristics influence equilibrium torque viscosity. The power index n viscosity as function frequency was affected...

This paper focuses on the thermal properties of polystyrene/lignin composites over a wide range lignin content. Blending with and without compatibilizer (styrene/ethylene/butylene copolymer) was performed in an internal batch mixer to prepare samples between 0 80%wt lignin. From compounds, extensive study performed, including thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) dynamic mechanical (DMTA). TGA results indicated that stability polystyrene increases...

Abstract High density polyethylene (HDPE) foams (450–950 kg/m 3 ) were prepared by compression molding and their tensile moduli measured in order to study the normalized elastic modulus as a function of closed‐cell foams. The data then used compare several models cellular materials polymer composites determine which would fit our results. Of all used, simple empirical equation Moore (square power‐law) differential scheme predict very well range voids volume fraction under (0–55%). © 2003...

Abstract High density closed‐cell polyethylene foams (450–950 kg/m 3 ) were prepared by compression molding, and their flexural tensile moduli measured in order to study (1) the normalized modulus as a function of density, (2) effect thin skins on moduli. For data, it was found that model Gonzalez I‐beam Hobbs predicted data very well range void volume fractions under (0–55%). combination differential scheme or square power‐law with sandwich structure gave best predictions. Finally, we have...

Abstract The improvement of Brinell hardness sugar maple ( Acer saccharum Marsh.) samples through impregnation and in‐situ polymerization methyl methacrylate, 2‐hydroxylethyl ethylene glycol dimethacrylate monomers was investigated. formulation combinations were determined by a mixture design. Sugar impregnated with these mixtures vacuum pressure process polymerized in situ catalyst‐thermal procedure. effects the their on modulus analyzed. Chemical enhanced both modulus. A significant...

Abstract The room temperature tensile properties of closed‐cell polyethylene foams have been investigated. High density (HDPE) four different molecular weight were used to study the effect and foam on mechanical during tension at break point. It was found that increasing changes behavior from brittle ductile fractures. For foams, strength follows a square power‐law model strain is independent volume fraction voids. normalized yield also relation with density, similar value solid polymer...

Abstract In this study, sugar maple samples were impregnated with three impregnants by a vacuum and pressure process in situ polymerized catalyst-thermal procedure. The effects of polymeric monomers their combinations on monomer retention volume (MR V ) weight W polymer (PR) analyzed the wood was examined scanning electronic microscopy (SEM). methacrylates chosen as methyl methacrylate (MMA), hydroxyethylene (HEMA) ethylene glycol dimethacrylate (EGDMA). formulation determined mixture...

Polymerization-filled composites (PFC) and melt-blended (MBC) of Kevlar pulp/high density polyethylene were prepared to compare their mechanical properties. It was found that break strains PFC by far higher than MBC for a similar fiber concentration. Tensile data then used several models short polymer composites. Of all the tested, it Berlin's approach in combination with Rosen's model critical aspect ratio give reasonable prediction. also fiber's is strongly related processing technique used.

High density closed-cell HDPE foams (450–950 kg/m3) were prepared by compression molding, and torsion rectangular tests performed to measure their shear modulus in order study: (1) the relationship between as a function of density, (2) determine effect thin skins. Based on assumption that twist stiffness (product moment inertia) is sum skin layers core part, several structural foam models are proposed. We found give better results than uniform models, indicating skins have an important polymer foams.

Abstract Nine formulations were selected for evaluating the effect of different curing methods on pH and alkalinity or acidity various structural wood adhesives. These included four phenol–formaldehyde (PF) resins with high pH, one phenol–resorcinol–formaldehyde (PRF) resin intermediate two melamine–urea–formaldehyde (MUF) resins, melamine–formaldehyde (MF) low pH. The used in study were: (1) at 102–105°C 1 h (based CSA O112.6‐1977), (2) four‐hour 66°C followed by 1‐hour 150°C ASTM...

Abstract Wood–plastic composites were prepared through impregnation of solid wood with polyethylene. A resolution IV screening design 16 runs for seven factors at two levels was adopted. The tested ratio maleated polyethylene in formulations, different molecular weights, four process (vacuum, pressure, time, and temperature), species (red maple aspen). Moisture adsorption content volumetric changes as a function time investigated. This study also examined the effects parameters impregnants...