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Thermal diffusivity (D) and thermal conductivity (κ) of harzburgite and dunite from Luobusha ophiolite were simultaneously measured up to 3 ​GPa and 823 ​K using the transient plane-source method in a multi anvil apparatus. The results show that the values of D and κ of both samples systematically decrease with increasing temperature and increase with increasing pressure. By combination of the thermal physical data of rocks and minerals and geophysical constraints, we performed numerical simulation on the thermal evolution of Tibet vary over depth, distance and geologic ages. The present results provide new constraints on occurrence of partial melting and its geophysical significance beneath Tibetan crust.

This paper mainly discussed the experimental relationships between electrical properties and geological parameters such as brittle mineral content, total organic carbon (TOC) content and microscopic pore structure, with examples from Longmaxi organic shale in Sichuan province of China. With results derived from X-ray diffraction, organic geochemical measurements, nitrogen adsorption method and tests of rock electrical parameters, we came to the conclusions as follows: (1) Shale samples dominated by organic pores have the lowest resistivity, medium resistivity was found in samples mainly containing intraparticle pores and intergranular pores, and intercrystal pore dominated samples have the highest resistivity. (2) Brittle mineral content has positive correlation with rock's resistivity, as well as porosity and connectivity of intergranular pores. Low brittle mineral content suppresses electric double layers where ions exchange with clay minerals, ultimately resulting in increasing rock resistivity and decreasing rock polarizability. (3) High TOC content (>3%) is the most critical factor contributing to low organic shale resistivity, as increasing TOC content improves pore structure and reduces resistivity. The isomorphic substitution of the organic matter also serves to enhance shale conductivity and polarization. (4) Pyrite content has negative correlation with resistivity, while positive correlation with polarizability. Our study thus provides a series of basic parameters for shale gas exploration and exploitation, and discusses the geological features of significance for shale gas development in the Longmaxi Formation of this area. This is achieved by the determination of rock electrical parameters, which can be used to judge organic carbon and brittle mineral content to delineate shale areas as ‘brittle shale sweet spots’. In addition, in the process of monitoring hydrofracturing, the electrical characteristics of the low resistivity anomaly correspond to the possible existence of a fracture or fracture zone, which could provide more reliable geological structure information for the later exploitation of shale gas.

Pinus taeda suspension cultures grown in medium containing 2,4-dichlorophenoxyacetic acid showed only primary cell wall formation and essentially no lignification, as determined by histochemical, ultrastructural, chemical, and NMR spectroscopic analyses. However, these cultures maintained a functional phenylpropanoid pathway as demonstrated by formation of the lignans (-)-matairesinol and (-)-pinoresinol. Administration of [1-13C]Phe to these cultures, followed by solid-state carbon-13 NMR spectral analysis of their cell walls, demonstrated that the phenylalanine incorporated into the cell wall matrix was primarily as protein, rather than lignin. Successive transfer of the 2,4-dichlorophenoxyacetic acid-grown cultures to alpha-naphthaleneacetic acid-containing medium induced cell wall thickening concomitant with lignification. The presence of lignin was confirmed by histochemical, ultrastructural, chemical, biochemical, and NMR spectroscopic analyses. Specific labeling of the lignin polymer in situ with [1-13C]-, [2-13C]-, and [3-13C]Phe and analysis of the cell wall preparations by solid-state carbon-13 NMR spectroscopy permitted the first direct determination of the in situ bonding patterns in a gymnosperm lignin. Several dominant interunit linkages were observed, including beta-O-aryl, furanofuran, phenylcoumarin, and phenolic-linked monolignols, consistent with those predicted but hitherto not proven. Finally, milled wood lignin derivatives prepared from these 13C-specifically enriched lignin tissues gave a relatively high fidelity copy of the native lignin.