conditions of the depositional environment, water salinity, and thermal maturity of organic matter. Apparently, a weak-reducing environment with brackish water seems to contribute to the formation and enrichment of short- chain steranes. The abundances of these compounds relative to regular steranes increase with the increasing maturity of the oils, which may be possibly attributed to thermal stability reasons. Source-related biomarkers uncover the primary origin of short-chain steranes may be related to algae.

Zhang, P., Huang, P., Xu, X., Sun, H., Jiang, B., Liao, Y., 2020. Spectroscopic and molecular characterization of biochar-derived dissolved organic matter and the associations with soil microbial responses. Science of The Total Environment 708, 134619.

http://www.sciencedirect.com/science/article/pii/S0048969719346108 Dissolved organic matter (DOM) released from biochar can influence the microbial community structure, but the inherent mechanism associated with the structure of biochar-derived DOM remains insufficiently elucidated. In this study, the spectroscopic characteristics and molecular structures of biochar-derived DOM were studied, and the microbial responses to biochar-derived DOM were explored. With increasing biochar pyrolysis temperature (PT), the molecular weight and proportions of aliphatic and fulvic acid-like compounds in the biochar-derived DOM decrease along with an reduction in the amount of DOM released from the biochars, but the proportions of combustion-derived condensed polycyclic aromatics and humic acid-like and soluble microbial byproduct-like compounds increased. Accordingly, the humification index, H/C and (O+N)/C values also decreased. The spectroscopic characteristics of biochar-derived DOM were distinct from those of natural substrates. Moreover, the DOMextracted from biochar raw materials contained a high proportion of aliphatic compounds, while the DOM derived from high-PT biochars (500 °C) had similar characteristics to fulvic acid- like and soluble microbial byproduct-like compounds. The microbial abundance and community structure Dyadobacter varied in different DOM solutions. The relative abundances (RAs) of eight genera (e.g. , Sphingobacterium Novosphingobium and ) had significantly positive correlations with the content of aliphatic Methylotenera Acinetobacter Reyranella compounds, while RAs of seven genera (e.g. , and ) had significant positive correlations with the content of high-aromatic combustion-derived condensed polycyclic aromatics. These results are helpful for obtaining a deep understanding of the potential influences of various types of biochar-derived DOM on terrestrial and aquatic microbiology.

Zhang, 2 Zhang, 2 P., Lu, S., Li, J., Chang, X., 2020. D and D Nuclear magnetic resonance (NMR) relaxation behaviors of protons in clay, kerogen and oil-bearing shale rocks. Marine and Petroleum Geology 114, 104210.

http://www.sciencedirect.com/science/article/pii/S0264817219306646 T T T Few 1D and 2D - Nuclear magnetic resonance (NMR) studies have focused on oil-bearing shales with 2 1 2 complex constituents and a deeper understanding of the NMR relaxation behaviors of oil confined in shale is T T T needed. In this paper, a series of and - NMR experiments were performed on oil-bearing shale and its 2 1 2 T T components (clay minerals and kerogen) to obtain the - fluid typing chart and analyze the adsorbed and free 1 2 oil in shale. The results were as follows: five types of water (bound, adsorbed, free, crystal and structural water) T T T T T in clay minerals were qualitatively identified and described by the specific to / ratio values, and - 2 1 2 1 2 T T maps were used to qualitatively indicate the clay type. The - fluid typing chart containing the signatures of 1 2 8 proton populations in oil-bearing shale was defined and included bulk liquid, macropore (>1000 nm) oil, nanopore (<1000 nm) oil, and free water in clay minerals or kerogen, shale pore water, bound water in clay minerals, kerogen and crystal water. Adsorbed oil was mainly confined in nanopores, especially micropores smaller than 100 nm, while free oil composed of movable and irreducible oil was predominant in mesopores (100 - 1000 nm) and macropores. Furthermore, the proportion of irreducible oil gradually decreased and that of T T movable oil gradually increased from mesopores to macropores. The results demonstrate that the - NMR 1 2 technique may be an effective method for the assessment of fluid distributions and proton mobility and has potential applications for the characterization of shale oil occurrence states.

Zhang, Q., Wang, W.-D., Kade, Y., Wang, B.-T., Xiong, L., 2020. Analysis of gas transport behavior in organic and inorganic nanopores based on a unified apparent gas permeability model. Petroleum Science 17, 168 - 181.