Petroleum migration process of Bamianhe oilfield of Dongying depression, East China is evaluated on the basis of our detailed work on geochemistry of the crude oil and the source. Molecular tracers, especially nitrogen compounds, are employed in assessing style of oil migration and accumulation. Additionally, absolute quantitative results of heteroaromatics including dibenzofuran, dibenzothiophene and fluorene with similar basic frames to pyrrolic nitrogenic compounds are also used to evaluate the quantity of petroleum migration. According to apparent migration effects of the pyrrolic nitrogen compounds, it is indicated that most of Bamianhe oil was derived from potential source kitchen-Niu-zhuang sag, migrated and accumulated at Bamianhe fault belt through selective paths according to a main filling point displayed. Generally, upward migration trend from the main point along the south slope is noted. There are observable migration effects from Guangli subsag to the north Bamianhe and Yangjiaogou oilfields showing Guangli subsag was a secondary kitchen accounting for the oils in the north portion. Significant vertical migration effects shown in several cross sections demonstrate that faults well developed in the area play an important role in oil migration and accumulation. Unformality, sandstone reservoirs distributed locally also suggest important fairways in connecting sources with traps. The tectonic and a combination of tectonic and lithological mechanism are identified as the critical mechanisms in entrapping hydrocarbons. Migration trend suggested by nitrogenic compounds agrees well with analysis of lateral compositional variety and thermal maturity gradient. This study also confirms well with our previous studies. It is the location of source rocks, tectonic and stratigraphic characteristics that have a comprehensive control on the model of hydrocarbon migration and accumulation in Bamianhe oilfield. Results also show that the oils are mostly derived from...
Considering the existing problems of the petroleum system, this paper brings forward the concept of natural gas accumulation system and presents the dividing principles. Then detailed statistics on the accumulation factors of the 32 typical natural gas accumulation systems in China and studies on the laws controlling distribution of gas are collected. The research shows that the petroleum accumulation system is the basic unit controlling petroleum generation, migration and accumulation. Generating intensity, generating amount, accumulating efficiency and migration distance plays an important role in the distribution of natural gas. Through analysis on results of resources evaluation, discovered reserves and residual reserves, potential areas in middle-scaled petroliferous basins in China are forecasted in this paper. Ordos, Sichuan, Tarim and Qaidam basins are found out to be the main basins developing and enriching gas accumulation systems.
A major problem in hybrid rice production is the occurrence of leaf senescence during the grain filling stage that can result in reduction of yield. Changes in contents of several endogenous hormones are related to leaf senescence. The relationship between endogenous hormones and leaf senescence in the rice hybrid Tiyou 418 and its parents Tijin and C418, was undertaken for investigation. Indicators of leaf senescence, including superoxide dismutase (SOD) activity, malondialdehyde (MDA) accumulation and chlorophyll content, as well as the contents of abscisic acid (ABA), zeatin riboside (ZR), gibberellin (GA1/3) and auxin (IAA) in the leaves were determined. Different rates of leaf senescence were observed in the three materials. Senescence occurred earliest and fastest in Tijin, followed by Tiyou 418 and then C418. A similar trend was recorded in ABA, ZR, and IAA contents during the grain filling stage in the three materials. Changes in (GA1/3+ZR+IAA)/ABA ratios were also similar, being quite stable during the early stage of leaf senescence, and decreasing markedly during the late stage. The ratio declined more dramatically in Tijin, in accordance with its faster leaf senescence. The results suggest that the ratio of (GA1/3+ZR+IAA)/ABA regulates chlorophyll content, SOD activity, MDA content and membrane lipid peroxidation. It is postulated that endogenous hormones may play a role in the regulation of leaf senescence in a systematic way.
Spin-polarized transport properties in Fe /insulator (Ⅰ) (semiconductor (S)) / Co / I (S) / Fe double junction systems are investigated theoretically, current density is asymmetry as function of the direction of applied bias, and evaluated using generalized formalism base on the non-equilibrium Green‘s function, which is implemented with calculation of real space Green‘s function in tight-binding model in linear response region.