Development of a net ozone production rate detection system based on dual-channel cavity ring-down spectroscopy.

A novel system for measuring net photochemical ozone production rates in the atmosphere based on cavity ring-down spectroscopy (OPR-CRDS) was developed. The system consists of two chambers (a reaction chamber and a reference chamber) and a dual-channel O-CRDS detector. To minimize the wall loss of O in the chambers, the inner surfaces of both chambers are coated with Teflon film.

High HO-Assisted Proton Conduction in One Highly Stable Sr(II)-Organic Framework Constructed by Tetrazole-Based Imidazole Dicarboxylic Acid.

Solid electrolyte materials with high structural stability and excellent proton conductivity (σ) have long been a popular and challenging research topic in the fuel cell field. This problem can be addressed because of the crystalline metal-organic frameworks' (MOFs') high structural stability, adjustable framework composition, and dense H-bonded networks. Herein, one highly stable Sr(II) MOF, {[Sr(Htmidc)(HO)]·4HO} () (Htmidc = 2-(1H-tetrazolium-1-methylene)-1H-imidazole-4,5-dicarboxylic acid) was successfully fabricated, which was structurally characterized by single-crystal X-ray diffraction and electrochemically examined by the AC impedance determination.

A three-channel thermal dissociation cavity ring-down spectrometer for simultaneous measurement of ambient total peroxy nitrates, total alkyl nitrates, and NO.

A newly constructed thermal dissociation cavity ring-down spectrometer (TD-CRDS) for the simultaneous measurement of ambient total peroxy nitrates (ΣPNs, RONO), total alkyl nitrates (ΣANs, RONO), and NO was presented in this work. ΣPNs and ΣANs were detected as NO with the CRDS instrument after thermal dissociation. PNs and ANs completely dissociated at 180 °C and 360 °C, with conversion efficiencies of 96 % and 99 %, respectively.

A Mid-Infrared Quantum Cascade Laser Ultra-Sensitive Trace Formaldehyde Detection System Based on Improved Dual-Incidence Multipass Gas Cell.

Formaldehyde (HCHO) is a tracer of volatile organic compounds (VOCs), and its concentration has gradually decreased with the reduction in VOC emissions in recent years, which puts forward higher requirements for the detection of trace HCHO. Therefore, a quantum cascade laser (QCL) with a central excitation wavelength of 5.68 μm was applied to detect the trace HCHO under an effective absorption optical pathlength of 67 m.

Nocturnal atmospheric chemistry of NO and NO over Changzhou in the Yangtze River Delta in China.

Comprehensive observations of the nocturnal atmospheric oxidation of NO and NO were conducted at a suburban site in Changzhou in the YRD using cavity ring-down spectroscopy (CRDS) from 27 May to 24 June, 2019. High concentrations of NO precursors were observed, and the nocturnal production rate of NO was determined to be 1.7 ± 1.

Vertical characteristics of NO and HCHO, and the ozone formation regimes in Hefei, China.

The research on the mechanism of combined air pollution in the Yangtze-Huaihe region, which is characterized by unique meteorological and geographical conditions and pollution emission characteristics, is still insufficient. We performed an experiment on key pollutants and an ozone formation study in Hefei, which is a pivotal city in the Yangtze-Huaihe region, from September 1 to 20, 2020. The aerosols retrieved via two-dimensional Multi-axis Differential Optical Absorption Spectroscopy (2D-MAX-DOAS) with a Boltzmann-shaped a priori profile had the best agreement with the results of Light Detection and Ranging (LIDAR) and sun-photometer measurements among the three typical a priori profiles (Gaussian, Boltzmann, and exponential shapes).