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Strong pulse is a special kind of single pulse that manifests as strong radio bursts. We present the strong pulse emission properties from PSR B1237+25 at 1540 MHz using the Nanshan 25 m radio telescope. Their peak flux densities range from 10.2 to 82.5 times that of the average pulse profile. We perform fit for the statistical distributions for the peak flux density ratio, S/N (signal-to-noise ratio), and W 50 (full width of half maximum, FWHM) with lognormal curves. We first discover a weak innermost cone around the core at 1540 MHz. The new discovered cone belongs to the partial cone categories, and its leading edge is too weak to detect. Our analysis of the structures of the three cones shows that the new innermost cone is located close to the core component, and the emission height increases from innermost to outermost cones at a step of 300 km.

Based on the analysis of C30*/C30H thermal stability, C30*/C30H feasibility in hydrocarbon-charging migration, the results show that C30*/C30H might not only show a good response to thermal maturity in mature to high mature oil. Comparing C30*/C30H parameters with methyl dibenzothiophene ratio (MDR), exposure/shielding alkyl dibenzothiophenes, found that the C30*/C30H parameters and two other parameters have great positive correlation, indicating that the C30*/C30H parameters are not only good thermal maturity parameters but also good in hydrocarbon-charging migration. Using C30*/C30H parameter tracer, Chang 7 oil reservoir group of hydrocarbon-charging migration direction in Longdong area appears as the main hydrocarbon charging in Hua Chi area. The oil migration directions are southwest and northeast, and hydrocarbon charging occurs by the wave surface filling migration; also, the oil has the characteristics of continuous filling. Preliminary results show that C30*/C30H parameter is an effective...

Based on the analysis of the hydrocarbon geochemical characteristics in the Kuqa petroleum system of the Tarim Basin, this study discusses the causes and controlling factors of the phase diversities and their differences in geochemical features. According to the characteristics and differences in oil and gas phase, the petroleum system can be divided into five categories: oil reservoir, wet gas reservoir, condensate gas-rich reservoir, condensate gas-poor reservoir and dry gas reservoir. The causes for the diversities in oil and gas phases include diversities of the sources of parent material, maturity of natural gas and the process of hydrocarbon accumulation of different hydrocarbon phases. On the whole, the Jurassic and Triassic terrestrial source rocks are the main sources for the hydrocarbon in the Kuqa Depression. The small differences in parent material may cause diversities in oil and gas amount, but the impact is small. The differences in oil and gas phase are mainly affected by maturity and the accumulation process, which closely relates with each other. Oil and gas at different thermal evolution stage can be captured in different accumulation process.

Gas chromatography fingerprint technique has the advantages of fast performance and low cost. It can be used to conduct analysis without interruption either in the field or at laboratory. This technique has been used successfully in such cases that conventional production logging techniques are powerless. Taking low-concentration anthracene as internal standard, we calculated the absolute concentrations of fingerprints, initially made some experiments directly on biodegradation of crude oils, and calculated production allocation in the Gudong Oil field. Compared with the production logging, this method has made up for the deficiencies of the former GC fingerprint technique. It will find wide applications in monitoring the trend of production in various oil-fields.

Field and laboratory analyses of carbonate rock samples from the Qiangtang Basin, Tibet, indicate that carbonate source rocks are mainly developed in the Middle Jurassic Xiali Formation and Upper Jurassic Suowa Formation. Comprehensive studies showed that the Suowa Formation carbonate source rocks have a favorable hydrocarbon-generating potential. The abundance of organic matter in the carbonate rocks is controlled mainly by sedimentary environment and inorganic compounds in the rocks, which is higher in the restricted platform facies than in the open platform facies. Organic carbon contents decrease with increasing CaO contents in the source rocks.