[Determination of individual components in finished motor gasoline by dual-channel three-column gas chromatography].

A method based on a dual-channel gas chromatograph equipped with three columns and three detectors was established for the determination of individual components in finished motor gasoline. The gasoline samples were separately introduced into the two injection ports of the chromatograph using two autosamplers. The components of the sample introduced into the first injection port (channel 1) were separated on a nonpolar PONA column (50 m×0.

Optically Controlled Nano-Transducers Based on Cleaved Superlattices for Monitoring Gigahertz Surface Acoustic Vibrations.

Surface acoustic waves (SAWs) convey energy at subwavelength depths along surfaces. Using interdigital transducers (IDTs) and opto-acousto-optic transducers (OAOTs), researchers have harnessed coherent SAWs with nanosecond periods and micrometer localization depth for various applications. These applications include the sensing of small amount of materials deposited on surfaces, assessing surface roughness and defects, signal processing, light manipulation, charge carrier and exciton transportation, and the study of fundamental interactions with thermal phonons, photons, magnons, and more.

Diversity, community structure, and abundance of nirS-type denitrifying bacteria on suspended particulate matter in coastal high-altitude aquaculture pond water.

Denitrifying bacteria harboring the nitrate reductase S (nirS) gene convert active nitrogen into molecular nitrogen, and alleviate eutrophication in aquaculture water. Suspended particulate matter (SPM) is an important component of aquaculture water and a carrier for denitrification. SPM with different particle sizes were collected from a coastal high-altitude aquaculture pond in Maoming City, China.

Experimental and Theoretical Insights into the Effect of Dioldibenzoate Isomers on the Performance of Polypropylene Catalysts.

Experimental investigations and density functional theory (DFT) calculations were carried out to study the comprehensive effect of different 3,5-heptanedioldibenzoate (HDDB) optical isomers as the internal electron donor on the catalytic performance of Ziegler-Natta catalysts. The experimental catalytic activity of HDDB has a positive correlation with the relative content of the mesomer incorporated during catalyst preparation, while the hydrogen response of HDDB displayed a negative correlation with the relative content of the mesomer. In order to apply the DFT calculation results to the macroscopic activity of the catalyst, the content of the active centers of the catalyst was analyzed.

Coherent Phonons in van der Waals MoSe/WSe Heterobilayers.

The increasing role of two-dimensional (2D) devices requires the development of new techniques for ultrafast control of physical properties in 2D van der Waals (vdW) nanolayers. A special feature of heterobilayers assembled from vdW monolayers is femtosecond separation of photoexcited electrons and holes between the neighboring layers, resulting in the formation of Coulomb force. Using laser pulses, we generate a 0.

Predictive Value of a Quick Pitt Bacteremia Score for Prognosis of Patients with Bloodstream Infection Secondary to Urinary Tract Infection: A Retrospective Cohort Study.

Purpose: To analyze the effect of a quick Pitt bacteremia score (qpitt) on the prognosis of patients with bloodstream infection (BSI) secondary to urinary tract infection (UTI) and to further explore its use in aiding appropriate selection of initial antibiotic treatment.

Methods: Medical records of patients with BSIs secondary to UTIs who were admitted to our hospital from January 2018 to December 2020 were retrospectively collected. To screen for independent risk factors, logistic analysis was conducted on statistically significant variables.

Determination of trace organic chlorides in hydrogen for fuel cell vehicles by gas chromatography coupled with ion mobility spectrometry.

A method for the determination of organic chlorides in hydrogen for fuel cell vehicles by gas chromatography coupled with ion mobility spectrometry was established. Organic chlorides were separated by a non-polar gas chromatography column and detected in the negative ion mode of the ion mobility spectrometer. The effect of operating parameters of ion mobility spectrometer including drift gas flow rate and drift tube temperature on sensitivity and resolution were evaluated.

Application of Chlorine Dioxide in Cell Surface Modification to Enhance Its Mechanical Stability and Metal Ion Adsorption.

There has been a trend toward the use of microorganisms as the biomaterial for removing dyes and metals from wastewater. However, native microorganism cells have low mechanical stability, which limit their further application in industries. In this study, chlorine dioxide (ClO), a high-efficiency, low-toxicity, and environmentally benign disinfectant, was used for microorganism surface modification to enhance the mechanical stability and metal ion adsorption of the cell.

Dynamic optical arbitrary waveform generation with amplitude controlled by interference of two FBG arrays.

In this paper, a novel structure of dynamic optical arbitrary waveform generation (O-AWG) with amplitude controlled by interference of two fiber Bragg grating (FBG) arrays is proposed. The FBG array consists of several FBGs and fiber stretchers (FSs). The amplitude is controlled by FSs through interference of two FBG arrays.

[Bactericidal effects of chlorine dioxide by respiratory inhibition].

Objective: Chlorine dioxide (ClO2) is a highly effective disinfectant for food and potable water treatment. However, knowledge on its action mechanism remains unexplored. The present study aims to determine the role of respiratory inhibition in the bactericidal effects of ClO2.

[Application of gas chromatography in research of biodiesel processing].

Applications of gas chromatography in the research of biodiesel processing are reviewed with 27 references, including the analysis of fatty acid methyl esters (FAME) in the reaction products and final biodiesel, the determination of mono-, di- and tri-glycerides, the contents and distribution of free fatty acids, and the determination of trace methanol in biodiesel. The effects of various factors for analysis of the reaction products are discussed, such as injection mode, column type and silylation. A method for the determination of trace methanol in biodiesel products with dual-columns and pressure backflush system is proposed.

[Analyses of gasoline range hydrocarbons by gas chromatography].

Analyses of gasoline range hydrocarbons by gas chromatography are reviewed with 66 references. Methods of high resolution capillary gas chromatography, multidimensional gas chromatography, and gas chromatography with atomic emission detection after bromination are summarized respectively. The advantages and limitations of each method are discussed and solutions for some existing problems are proposed.

[Alkene bromination used for detailed hydrocarbon and bulk hydrocarbon group-type analysis of gasolines containing alkenes].

The optimized reaction conditions of selective alkene bromination for gasolines containing aromatics and saturated hydrocarbons are presented. By this way, the interfering problem in alkene determination from coeluting saturated hydrocarbons has been solved. So the detailed hydrocarbon analysis can be improved by a simple system containing polar and non-polar columns or by a gas chromatograph coupled with an atomic emission detector (GC-AED).