Ancient ivory, from the Chengdu Jinsha and Guanghan Sanxingdui sites in China, has been buried for several thousand years. In order to determine the degradation mechanisms and to provide a scientific basis for protecting them, these ancient ivory samples have been compared with modern ivory using infrared spectroscopy in the frequency range 400À4000 cm À1 . By combining chemical analysis data we compare the crystallinity and crystal chemistry of the apatite component, as well as the structural characteristics of the ivory. These investigations showed that the ancient ivory consists almost entirely of hydroxyl-carbonate apatite as the predominant phase. Compared with the modern ivory, the PO 4 3À and CO 3 2À bands are stronger, the PO 4 RF values are obviously greater, and an extra OH À band at 3569 cm À1 is observed in the ancient ivory. These results indicate that there is a greater degree of apatite crystallinity in the ancient ivory and also imply that there has been incorporation and recrystallization of CO 3 2À in the apatite during burial. Positive correlations have been found between the apatite crystallinity, CO 3 2À and OH À ion contents, and burial time. The organic matter in ancient ivory has been lost or decomposed as the organic bands (e.g. at 1238 cm À1 and 1337 cm À1 ) have disappeared. This may be the main reason that ancient ivory is easily dewatered and readily friable after being unearthed.

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Marine–continental transitional shale is one of the most promising targets for shale gas exploration in the Lower Yangtze region. To investigate the sedimentary environments and the regularity of the enrichment of the Longtan shale, multiple techniques including core and thin-section observations, geochemical and elemental analyses, X-ray diffraction, scanning electron microscopy (SEM), and low-pressure nitrogen adsorption (LPNA) were used to analyze the sedimentology, mineralogy, and pore structure of the Longtan shale. The core descriptions and thin-section observations showed that the Longtan shale was deposited in marine–delta transitional environments including delta-front, shore swamp, mixed tidal flat and shallow shelf environments. The Sr/Cu, V/Cr, CIA, EF (Mo), EF (U), and other major and trace element results indicated warm and moist climates and water-reducing conditions in the Longtan period. Both the climate and water conditions were favorable for organic matter production and preservation. The geochemical results showed that the Longtan shale was in the overmature stage (Ro values ranging from 2.4% to 3.57%) and that the average total organic carbon (TOC) content was 5.76%. The pore system of the Longtan shale consisted of inorganic pores with a small number of organic pores and microfractures. The porosity and specific surface area were mainly affected by the TOC and clay mineral contents. An effective combination of brittle mineral particles, organic matter, and clay minerals provided the necessary conditions for pore preservation. The organic pores, intergranular pores in clay minerals, and brittle mineral pores formed the main network system for the Longtan shale. In summary, the lithological combinations, organic geochemistry, and pore structure system were all affected by the sedimentary environments.

In order to further understand the heat resistance of paraffin and provide a scientific basis for the application of paraffin, the acid-alkali resistance, melting point, density, and compressive strength of fully refined 58# paraffin and its different temperature, heating products in the temperature range of the melting point to ignition point (58 ı C to 340 ı C) are systematically measured using the instruments such as the digital melting point apparatus and hydraulic universal material testing machine. And the mechanism is also discussed by infrared spectrometry and X-ray diffraction analysis. The results of our experiment showed that paraffin and its different temperature heating products are of good acid-alkali resistance, and their melting point remain unchanged because their molecular linkage is unchanged in the temperature range of the melting point to ignition point. Their compressive strength and density are almost unchanged in the range 58-150 ı C due to both molecular linkage and the crystal structure having unchanged. These results indicate that the paraffin is of good heat resistance in the range 58-150 ı C. The compressive strength and density tend to decrease gradually in the range 150-340 ı C, especially in 150-250 ı C, which is due to mainly that the adjustment of crystal structure has taken place in the temperature range.