and and synthetic fibers. The resulting mass spectra display 10,000 discrete peaks, corresponding to plastic additives released by thermal desorption and polymer degradation products generated by pyrolysis. These were used to characterize differences among plastic types, microplastic source materials, and environmental samples. Multivariate statistics and elemental composition analysis approaches were applied to analyze fingerprints from the mass spectra. This promising analytical approach is sensitive, (potentially) high-throughput, and can aid in the elucidation of possible sources of microplastics and perhaps eventually to the analysis of bulk environmental samples for plastics.

Zhang, X., Zhou, X., Hu, D., 2020. High-resolution paired carbon isotopic records from the Meishucun section in South China: Implications for carbon cycling and environmental changes during the Ediacaran-Cambrian transition. Precambrian Research 337, 105561.

http://www.sciencedirect.com/science/article/pii/S0301926819302530 13 Several prominent negative carbon isotope (δ C) excursions are observed during the Ediacaran-Cambrian (E- C) transition, reflecting large perturbations of the carbon cycle in the ocean - atmosphere system. These negative 13 δ C excursions have been linked to dramatic paleoenvironmental changes and been widely used as regional and global chemostratigraphic correlation tools. However, there is still much debate about their causes and 13 13 mechanisms. In this study, we report high-reso lution δ C records of both carbon ate (δ C ) and organic carb 13 carbon (δ C ) from the Meishucun section in South China. Combined with lithological variations and org 13 intrabasinal correlations, we find that the negative δ C excursions during the E-C transition in South China are 13 tightly linked with transgressive events. The existence of a large vertical (surface-to- deep water) δ C gradient 13 in a stratified ocean, and episodic incursions of C-depleted anoxic/euxinic deep waters into shallow water environment through enhanced upwelling or shoaling of the chemocline, may have contributed to these negative 13 13 δ C excursions. In addition, our results also imply a large reduction in the vertical δ C gradient during the E- org C transition, which may reflect the ventilation and oxygenation of the deep ocean. The corresponding expansion of oxic seafloor conditions and a large increase in the extent of habitable space for animals may have facilitated the radiation of metazoans during the Cambrian explosion.

Zhang, Y.-Y., Wei, X.-Y., Lv, J.-H., Jiang, H., Liu, F.-J., Liu, G.-H., Zong, Z.-M., 2019. Characterization of nitrogen-containing aromatics in Baiyinhua lignite and its soluble portions from thermal dissolution. Chinese Journal of Chemical Engineering 27, 2783-2787.

http://www.sciencedirect.com/science/article/pii/S1004954119307785 Soluble portions (SPs) 1 - 4 (SP -SP ) were afforded from sequentially dissolution and alkanolyses of Baiyinhua 1 4 lignite (BL) in cyclohexane, CH OH, CH CH OH, and (CH ) CHOH at 300 °C. They were analyzed with a gas 3 3 2 3 2 chromatograph/mass spectrometer and quadrupole exactive orbitrap mass spectrometer (QEOTMS) with an atmosphere pressure chemical ionization source in positive-ion mode, while BL was characterized with an X- ray photoelectron spectrometer (XRPES). The results show that the yields of SP and SP are much higher than 2 3 ca. those of SP and SP , and the total SP yield is 39.0%. According to the results of the analysis with XRPES, 1 4 pyrrolic nitrogens are the most abundant nitrogen existing forms in BL. Thousands of nitrogen-containing aromatics (NCAs) were resolved with QEOTMS and their molecular masses are mainly in the range of 200 - 450 u N O N O . The main NCAs are and class species with double bond equivalent values of 4 - 18 and carbon 1 1 1 2 number of 7 - 30. The nitrogen atoms appear in pyridines, quinolines, benzoquinolines or acridine, and dibenzoquinolines or naphthoquinolines, while the oxygen atoms exist in methoxy and furan rings.

Zhang, Y., Fang, T., Ding, B., Wang, W., Yan, Y., Li, Z., Guo, W., Zhang, J., 2020. Migration of oil/methane mixture in shale inorganic nano-pore throat: A molecular dynamics simulation study. Journal of Petroleum Science and Engineering 187, 106784.

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