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Tunable semiconductor lasers have many important applications such as wavelength division multiplexing, light detection and ranging, and gas detection. The increased interest in silicon photonics has led to the rapid development of miniaturized on-chip tunable semiconductor lasers. However, silicon has poor light-emitting properties. Therefore, realizing high-performance tunable semiconductor lasers requires the integration of light sources with silicon. In this study, we review silicon-based light source integration methods and the development of silicon-based integrated tunable semiconductor lasers. Considering that narrow-linewidth performance greatly expands the applications of tunable semiconductor lasers, methods for reducing the linewidth of tunable lasers are summarized. Finally, the development trends and prospects for silicon-based integrated light sources and silicon-based integrated tunable lasers are analyzed and discussed.

The micro‐ring resonator (MRR) is a crucial element in integrated photonics. It allows for the realization of various optical devices, including integrated filters, modulators, micro‐ring laser cavities, detectors, optical logic switches, and nonlinear optical devices. The development of integrated photonics has enabled the integration of these devices with other components into a photonic chip to perform specific functions. For instance, widely tunable MRR‐based lasers have been integrated with optical phased arrays (OPAs), detectors, and other elements to form a fully integrated LiDAR engine. Advances in nanofabrication have facilitated the miniaturization of nanophotonic phased arrays and on‐chip lasers. MRR‐based integrated external cavity lasers (ECLs) and integrated optical frequency combs (OFCs) have significantly enhanced the scanning and detection capabilities of LiDAR recently. Additionally, their size and power consumption have been continuously reduced, rendering them suitable for chip‐scale integration. This paper systematically reviews the major advancements of MRR‐based integrated lasers for chip‐scale LiDAR. [ABSTRACT FROM AUTHOR]

With the widespread adoption of Internet of Things (IoT) technology, the increasing number of IoT devices has led to a rise in serious network security issues. Botnets, a major threat in network security, have garnered significant attention over the past decade. However, detecting these rapidly evolving botnets remains a challenge, with current detection accuracy being relatively low. Therefore, this study focuses on designing efficient botnet detection models to enhance detection performance. This paper improves the initial population generation strategy of the Dung Beetle Optimizer (DBO) by using the centroid opposition-based learning strategy instead of the original random generation strategy. The improved DBO is applied to optimize Catboost parameters and is employed in the field of IoT botnet detection. Performance comparison experiments are conducted using real-world IoT traffic datasets. The experimental results demonstrate that the proposed method outperforms other models in terms of accuracy and F1 score, indicating the effectiveness of the proposed approach in this field. [ABSTRACT FROM AUTHOR]

A higher-order mechanical model of axially moving nanoscale beams with time-dependent velocity was developed in the framework of nonlocal stress gradient theory. Based on the correlation between effective and common nonlocal bending moments, a sixth-order partial differential equation of motion with respect to the transverse displacement was derived. Unlike some previous work which assumed the velocity of axially moving nanoscale beam to be a constant, a time-dependent axial velocity was considered for the nanoscale beams. The resonance vibration frequencies were obtained according to the governing equation of motion and corresponding boundary conditions. It was concluded a nonlocal nanoscale strengthening effect that the vibration frequencies of such axially moving nanostructure increase with stronger nonlocal effects, or a larger dimensionless nonlocal nanoscale parameter causes a higher vibration frequency. A jumping phenomenon in frequency field was observed, and the vibration frequency may decrease or increase with an increase in the axial average velocity. Critical speeds of the axially non-uniformly moving nanoscale beams were defined and determined, and the critical speed versus nonlocal nanoscale revealed step and strengthening effects. The theoretical results obtained were compared with some experimental data and good agreement was achieved. Subsequently, the steady-state and stability of such moving nanostructures including the principal parametric and combination resonances were analyzed using a multiple-scale method. Some beneficial analytical procedures and theoretical formulations at nanoscale were provided. Based on specific boundary conditions, the stability boundaries of the axially accelerating nanoscale beams were determined and the unstable regions were influenced by nonlocal nanoscale significantly. [ABSTRACT FROM AUTHOR]

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The biaxial loading experiments of the glass fiber resin web composites of solar panel are analyzed. The experimental method, theoretical analysis and data processing of two experiments are introduced. And also the equivalence of the data results of two experiments is compared. [ABSTRACT FROM AUTHOR]

In this article, the facile synthesis of sea urchin-shaped LiFePO 4 nanoparticles by thermal decomposition of metal-surfactant complexes and application of these nanoparticles as a cathode in lithium ion secondary batteries is demonstrated. The advantages of this work are a facile method to synthesize interesting LiFePO 4 nanostructures and its synthetic mechanism. Accordingly, the morphology of LiFePO 4 particles could be regulated by the injection of oleylamine, with other surfactants and phosphoric acid. This injection step was critical to tailor the morphology of LiFePO 4 particles, converting them from nanosphere shapes to diverse types of urchin-shaped nanoparticles. Electron microscopy analysis showed that the overall dimension of the urchin-shaped LiFePO 4 particles varied from 300 nm to 2 μm. A closer observation revealed that numerous thin nanorods ranging from 5 to 20 nm in diameter were attached to the nanoparticles. The hierarchical nanostructure of these urchin-shaped LiFePO 4 particles mitigated the low tap density problem. In addition, the nanorods less than 20 nm attached to the edge of urchin-shaped nanoparticles significantly increased the pathways for electronic transport., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)