Residual compensation algorithm for machine learning-based LIBS quantification optimization.

We propose a laser-induced breakdown spectroscopy (LIBS) quantitative prediction algorithm based on residual compensation that can effectively reduce the mean absolute error of prediction (MAEP) and mean relative error of prediction (MREP) by incorporating environmental and sample parameters into the prediction model. A 10-fold cross-validation of the residual compensation model based on four common models, support vector machine regression (SVR), partial least squares regression (PLSR), random forest regression (RFR), and K-nearest neighbor regression (KNNR), was applied to test the aluminum alloy samples. After testing on 10 elements, MAEP and MREP were reduced by an average of 51.

Laser-induced damage thresholds in SiO-coated aluminum mirrors under various ultrashort pulse widths.

The influence of laser temporal parameters on the laser-induced damage threshold (LIDT) is particularly complex due to the variation and uncertainty in damage mechanisms associated with different pulse widths, especially in the range that bridges transitional damage mechanisms. Metallic mirrors are ideally suited for ultrashort pulse optical systems owing to their broad spectral range. A comprehensive understanding of the damage behavior of metallic mirrors under ultrashort pulse widths is crucial for optimizing their performance and manufacturing processes.

Prediction model for assessing HER2 status patient with invasive ductal carcinoma based on clinical parameters and ultrasound features: a dual-center study.

Objective: The assessment of Human Epidermal Growth Factor Receptor 2 (HER2) expression status is crucial for determining the eligibility of breast cancer (BC) patients for HER2-targeted therapies. This study aims to develop a nomogram model that incorporates multimodal ultrasound imaging features alongside clinicopathological characteristics to evaluate HER2 status.

Methods: A retrospective analysis was conducted on 456 breast cancer patients who underwent breast ultrasound between January 2019 and December 2021.

Boosting fluorescence efficiency via filling technique prepared photonic crystal composites.

Au-doped photonic crystals offer considerable potential for boosting optical signals, however, precisely controlling the distance between luminescent particles and Au nanoparticles (NPs) faces severe challenges. We proposed a "filling" technique to prepare porous Au-doped inverse-opal PC (IOPC) with encapsulated Au NPs uniformly dispersing in insulating silica. The effective separation between Au NPs and infiltrated luminescent quantum dots successfully addresses the issue of fluorescence quenching, enhancing the photoluminescence intensity by 106-fold.

The Effect of Cooling Layer Thickness and Coolant Velocity on Crystal Thermodynamic Properties in a Laser Amplifier.

Laser diode pumped solid-state lasers (DPSSLs) have been widely used in many fields, and their thermal effects have attracted more and more attention. The laser diode (LD) side-pumped amplifier, as a key component of DPSSLs, is necessary for effective heat dissipation. In this paper, instead of the common thermal analysis based only on a crystal rod model, a fluid-structure interaction model including a glass tube, cooling channel, coolant and crystal rod is established in numerical simulation using ANSYS FLUENT for the configuration of an LD array side-pumped laser amplifier.

Correction method for the influence of environmental factors on laser-induced breakdown spectroscopy.

Environmental factors include sample temperature, ambient gas composition, and pressure, which have a significant impact on the accuracy and stability of the analysis results of laser-induced breakdown spectroscopy (LIBS). In this study, a method for simultaneously correcting the influence of several environmental factors is proposed. When the calibration and application environment are different, only one sample is needed to be measured in the application environment to correct the influence of environmental factors, so that the calibration model can obtain good analytical accuracy in this environment.

Quantitative Analysis of Vacuum Induction Melting by Laser-induced Breakdown Spectroscopy.

Vacuum induction melting is a popular method for refining high purity metal and alloys. Traditionally, standard process control in metallurgy involves several steps, include drawing samples, cooling, cutting, transport to the laboratory, and analysis. The whole analysis process requires more than 30 minutes, which hinders on-line process control.

Light-emitting-diode-pumped active Q-switched Nd:YLF laser.

An active Q-switching light-emitting diode (LED)-pumped laser is demonstrated by Nd:YLF crystal with acousto-optic modulation for the first time. The spectrum-band pump characteristic is grasped to describe the essential difference between an LED pump and single-absorption-peak matching of laser-diode pump or no matching of lamp pump. An effective absorption spectrum concept is proposed to characterize the absorption features of the gain material with LED-band pumping.