The preconcentration/gas chromatography-mass spectrometry with FID detector method was used to observe the 115 atmospheric volatile organic compounds (VOCs) of Tai’an urban area in autumn 2020. The average volume fraction of VOCs during the observation period was (67.50±25.55)×10⁻⁹, dominated by alkanes (34.86%) and oxygenated volatile organic compounds (OVOCs) (32.03%). The atmospheric chemistry reactivity of VOCs was estimated using ozone formation potential (OFP) and the OH radical loss rate (L_OH), respectively. The OFP of Tai’an in autumn was (241.50±6.91)×10⁻⁹, mainly contributed by OVOCs (39.92%) and aromatics (33.03%). The calculated L_OH was 7.34±0.33 s⁻¹, which was dominated by OVOCs (56.32%). The contribution of VOCs to the potential for secondary organic aerosol (SOA) formation was estimated using the fractional aerosol coefficients (FAC), and the results showed that SOA formation potential was (366.58±37.80)×10⁻⁹, dominated by aromatics (98.79%). The results of the characteristic species ratio analysis showed that the VOCs of Tai’an in autumn were influenced by local sources such as traffic-related emissions, solvent use and combustion sources. The source apportionment results showed that the contribution of motor vehicle emissions to VOCs was the highest at 26.1%, with the contributions from gasoline vehicle exhaust emissions and diesel vehicle exhaust emissions being 19.4% and 6.7%. The contribution of solvent use and industrial sources to VOCs was comparable at 20.1% and 19.9%, respectively. The contribution of stationary combustion sources and liquefied petroleum gas (LPG) use was 16.2% and 12.3%, respectively. Biogenic sources contributed the lowest percentage of 5.4%.

Microfossils from cherts of the Liuchapo Formation at Bahuang section in eastern Guizhou Province were studied. Through thin section observation, a large number of spherical fossils were revealed, including one type with connected spheroids, and two types with dark outer wall. The former is systematically described, and a new genus Bahuangia gen. nov. is established. The connected bodies of Bahuangia are calabash- or chain-shaped, and resemble the budding unicellular fungi or bacteria in morphology. Spherical fossils similar to these Bahuang specimens are widely distributed in the late Ediacaran deep-water facies of the Yangtze Plate. Through this study, the understanding of deep-water life forms during the ECT is improved, and new materials for both regional stratigraphic correlation and early life evolution are provided.

Aiming at the problems in the current emergency management GIS systems integrated with atmospheric dispersion models, such as low spatio-temporal resolution and without 3D terrain, a set of three-dimensional gas diffusion simulation methods was proposed based on the CALPUFF model. The three-dimensional spatio-temporal distribution data of the gas diffusion concentration was obtained through multi-layer calculations, and the Marching Cubes visualization technology was used to read and display the data, achieving the dynamic gas diffusion effect in three-dimensional space. “12·23” Kaixian blowout accident was used as a case study and the simulation was carried out to compare with the actual situation in two and three dimensions. The results show that the three-dimensional calculation based on CALPUFF model has higher accuracy of the magnitude and spatial distribution of gas concentration, and the three dimensional spatio-temporal dynamic simulation has high resolution and reconstruction efficiency, achieving a good visual effect. It can better express the gas leakage process and diffusion pattern and provide an important auxiliary decision-making means for emergency management.

This study scrutinizes the petrological and geochemical signatures by systematically sampling three sections of Yurtus Formation, which deposited during the early Cambrian in the western margin of Tarim Basin. The redox conditions together with the intensity of primary productivity during Yurtus Formation deposition are reconstructed, which provide theoretical basis for the distribution of source rocks and evaluation of reservoir potentials. The extremely high Ba content (>1000 μg/g) and appearance of barite in the lower part of Yurtus Formation implies high primary productivity, which explains the substantive organic matter in the surface ocean and is also consistent with the abundant phytoplankton fossil record and high TOC content. The large positive excursion of δ¹⁵N (>8‰) in the lower parts of Yurtus Formation probably is resulted from denitrification or annamox, both of which occur only when O₂ is depleted. It may indicate that organic matter transporting from the surface ocean to deeper ocean could consume dissolved oxygen by the process of degradation, which would drive the condition of deeper ocean more reduced. Meanwhile, low Ge/Si values of cherts in the lower part of Yurtus Formation indicate normal seawater origin of Si input. Oversaturation state of silica promotes the organic matter preservation due to relatively fast cementation.