Surface Passivation of FeO Nanoparticles: Avoiding Degradation, Preserving Magnetism, and Facilitating Ligand Modification for Better Biomedical Analysis.

Magnetic iron oxide nanoparticles (FeO NPs) hold great potential for biomedical applications, yet their structural degradation and function loss under physiological conditions limit practical utility. To improve their performance, a surface passivation strategy for FeO NPs is herein communicated by platinum (Pt) decoration, due to its inertness and low surface-ligand exchange rate. This not only prevents FeO NP degradation in harsh biological media but also preserves their magnetism and enables rapid and stable modification of ligands, yielding high-fidelity FeO@Pt probes.

Ultrafast all-optical modulation based on graphene-microfiber.

We proposed and studied an all-optical modulator based on graphene-microfiber (GMF), and prepared GMF by transferring graphene to the surface of the tapered region of the microfiber. The all-optical modulation characteristics and ultrafast all-optical modulation characteristics of GMF under different light source combinations were studied, and the all-optical modulator was completed. The experimental results show that GMF can achieve all-optical modulation, and broadband pump light can modulate single-pulse signal light.

High-sensitivity optical fiber probe for simultaneous measurement of chloride ions and temperature.

A fiber optic probe for the simultaneous measurement of chloride ions and temperature is presented. The Ag/alginate composite film is used as the reflective surface of the Fabry-Perot interferometer (FPI) and is a sensitive film for the adsorption of chloride ions. The experimental results show that the Fabry-Perot (FP) response sensitivity is approximately 1.

Antiepileptic drug concentration detection based on Raman spectroscopy and an improved snake optimization-convolutional neural network algorithm.

A method for measurement of antiepileptic drug concentrations based on Raman spectroscopy and an optimization algorithm for mathematical models are proposed and investigated. This study uses Raman spectroscopy to measure mixed antiepileptic drugs, and an Improved Snake Optimization (ISO)-Convolutional Neural Network (CNN) algorithm is proposed. Raman spectroscopy is widely used in the identification of pharmaceutical ingredients due to its sharp peaks, no pre-treatment of samples and non-destructive detection.

Discovery and experimental verification of the spectral characteristics at different growth stages of Aurelia.

Under the dual pressure of human activities and global changes, jellyfish outbreaks have occurred frequently in China's offshore waters in recent years, with serious impacts on marine fisheries, coastal tourism, marine ecology and cooling water systems for coastal industries. In order to accurately identify the origin of Aurelia and to be more proactive in the prevention and control of Aurelia outbreaks, this article proposed the use of ultraviolet (UV) and fluorescence spectroscopy to detect the polyps, ephyrae and larvae of Aurelia at different growth stages. The AvaSpec-2048 UV visible fibre spectrometer and the F-7000 fluorescence spectrophotometer were used to focus on studying the UV absorption spectrum and three-dimensional fluorescence spectrum of the polyps, ephyrae, and larvae of Aurelia cultured under laboratory conditions.

A reflective, metal-rich atmosphere for GJ 1214b from its JWST phase curve.

There are no planets intermediate in size between Earth and Neptune in our Solar System, yet these objects are found around a substantial fraction of other stars. Population statistics show that close-in planets in this size range bifurcate into two classes on the basis of their radii. It is proposed that the group with larger radii (referred to as 'sub-Neptunes') is distinguished by having hydrogen-dominated atmospheres that are a few percent of the total mass of the planets.

A detection method of typical toxic mixed red tide algae in Qinhuangdao based on three-dimensional fluorescence spectroscopy.

Red tides occur every year in the Qinhuangdao sea area of China, including a variety of toxic algae and non-toxic algae. Toxic red tide algae have caused great damage to the marine aquaculture industry in China and seriously endangered human health, but most of non-toxic algae are important bait for marine plankton. Therefore, it is very important to identify the type of mixed red tide algae in Qinhuangdao sea area.

All-fiber LP-LP ultra-broadband mode converters based on T-superimposed long period gratings in PCF.

In order to cover the bandwidth of optical fiber communication, a LP-LP ultra-broadband mode converter based on triple superimposed long period grating in PCF is proposed and demonstrated. The transmission spectra of the D-SLPG with gratings pitches and the T-SLPG were simulated and analyzed. The simulation results on the D-SLPG indicate that the 3 dB bandwidth of the D-SLPG is more than 1.

Parallel array signal processing technology for spatial phase distortion correction in heterodyne detection.

The spatial phase distortion caused by a rough target causes a decoherence effect which, in turn, produces system sensitivity degradation. The decoherence phenomenon is the primary problem that restricts the application of active optical heterodyne detection, e.g.

Identification of ichthyotoxic red tide algae based on three-dimensional fluorescence spectra and particle swarm optimization support vector machine.

Acccurate identification whether red tide has ithyotoxicity is very significant for microalgae monitoring. In order to realize the rapid and non-destructive detection of ichthyotoxic red tide algae, a detection method combining three-dimensional (3D) fluorescence spectrum and particle swarm optimization support vector machine (PSO-SVM) was developed to monitor the ichthyotoxic red tide algae with cell concentrations from 10 cells/mL to 10 cells/mL. The contour maps contracted form three-dimensional fluorescence spectra of six common species of ichthyotoxic algae and eight common species of non-ichthyotoxic algae,which are analyzed to select the optimal emission and excitation wavelength span.

Highly sensitive temperature sensing probes based on liquid cladding elliptical micro/nanofibers.

A highly sensitive temperature probe based on a liquid cladding elliptical micro/nanofiber is proposed, which exploits a fiber loop mirror with an output port probe for remote and highly-sensitive measurements based on evanescent field coupling. The thermo-optical effective liquid cladding avoids the influence of other environmental parameters (except for temperature), while protecting the micro/nanofibers from external disturbance and contamination. This renders the sensing probe only sensitive to temperature changes, making it suitable for real-world temperature measurements.

[Refractive Index Insensitive Temperature Sensor Based on Cascading Single Mode Fiber with Few Mode Fiber].

A refractive index insensitive temperature sensor is proposed base on cascading single mode fiber with few mode fiber(FMF). During the sensor preparation, the splicing current is set to 100 mA, and a section of FMF is no core-offset splicing between two single-mode fibers. Therefore, it can motivate the transmission mode preferably and form optical fiber Mach-Zehnder interferometer.

Refractive index insensitive temperature sensor based on specialty triple-clad fiber.

A refractive index (RI) insensitive temperature sensor based on specialty triple-clad fiber (STCF) is proposed. Based on coupling mode theory, the STCF can be equivalent to a rod waveguide and two tube waveguides. Then the cladding mode resonance characteristic of STCF is analyzed by calculating different mode dispersion curves, which indicates that it works only on the mode resonance from core to the fluorine-doped silica cladding, and finally a resonance wavelength can be obtained.

[The nitrate and temperature impact analysis in the detection of COD by UV spectrum].

Configured standard solution of chemical oxygen demand with potassium hydrogen phthalate was used as experimental subjects, collected ultraviolet absorption spectra of the standard solution in the range of 1,800 mg x L(-1), were collected, and PLS (partial least squares) algorithm was used to establish the correction model of different spectral region, the results showed that. The model in the spectral region of 265-310 nm had the highest correlation and smallest error; In order to eliminate the impact of nitrates and temperature on the detection of the COD , studied the changes of the UV absorption spectrum with different concentrations of sodium standard solution and different temperature. The results showed that absorption of nitrate in 208-238 nm was apparent, and the model for spectral region of 265-310 nm was free from the influence of nitrate; In the full range of spectrum, temperature rising leads to an increase in absorbance, thus the temperature compensation model was established for the different spectral region through predictive analysis.

[The turbidity and pH impact analysis of low concentration water chemical oxygen demand ultraviolet absorption detection].

Configuration standard solution in the concentration range of 1 - 25 mg x L(-1) of potassium hydrogen phthalate was used as experimental subject, Ultraviolet absorption spectra was collected, the COD quantitative analysis model was established by partial least squares with different pretreatment methods and the turbidity of the compensation effect analysis was given. The results show the model uses smoothing first derivative pretreatment method, internal cross validation RMSECV root mean square value of 0.122 27, principal component number 4, the square of the prediction model correlation coefficient is 0.

[Research on and application of hybrid optimization algorithm in Brillouin scattering spectrum parameter extraction problem].

This paper presents a novel algorithm which blends optimize particle swarm optimization (PSO) algorithm and Levenberg-Marquardt (LM) algorithm according to the probability. This novel algorithm can be used for Pseudo-Voigt type of Brillouin scattering spectrum to improve the degree of fitting and precision of shift extraction. This algorithm uses PSO algorithm as the main frame.

[Determination of chemical oxygen demand in water using near infrared transmission and UV absorbance method].

Chemical oxygen demand (COD) is a synthetical indicator which represents the degree of organic pollution in water. The near-infrared (NIR) transmission and the UV absorbance method based on photoelectric detection technology and spectroscopy analysis have some advantages such as high precision, speed, non-contact, no secondary pollution etc compared to conventional wet chemical method. The NIR transmission spectra and UV absorbance spectra of standard solution configured with phthalate hydrogen potassium were collected respectively by MPA FTIR spectrometer (Bruker Optics Inc.

[Immune protection of tegument protein rSj29 against Schistosoma japonicum in mice].

Objective: To clone, express and characterize a tegument protein gene of Schistosoma japonicum (Sj29) , and investigate the immune protection of the recombinant protein against S. japonicum in mice.

Methods: The gene coding for Sj29 protein was amplified by PCR, and the sequence was analyzed by bioinformatics tools.