The Qingxi Depression, over an area of merely 490 km2, is a petroliferous depositional center within the Jiuxi Basin. Lower Cretaceous source rocks in this depression are a suite of mudstones, dolomitic mudstones and ...The Qingxi Depression, over an area of merely 490 km2, is a petroliferous depositional center within the Jiuxi Basin. Lower Cretaceous source rocks in this depression are a suite of mudstones, dolomitic mudstones and argillaceous dolostones formed in a deep lacustrine environment. Although their distribution area is small, their thickness is sizable. High abundance and favorable types of organic matter provide an important material basis for petroleum generation. The majority of the source rocks in the Qingxi Depression are of maturation conditions for generating significant volumes of petroleum, and with only one peak generation period that commenced in the Neogene. The Himalayan movement results in a northerly overthrusting of the Qilian Mountains nappe to form a series of compressional faults, shear faults and rock fractures, all of which serve as main conduits for petroleum migration from west to east, and, in addition, as the reservoir space of the Qingxi Oilfield. Based on these factors, it is suggested that the future exploration be on the Qingxi low bulge and favorable fracturing zone within this depression.展开更多
We propose and study a predator prey model with state-dependent delay where the prey population is assumed to have an age structure. The state-dependent delay appears due to the mature condition that the prey must spe...We propose and study a predator prey model with state-dependent delay where the prey population is assumed to have an age structure. The state-dependent delay appears due to the mature condition that the prey must spend an amount of time in the immature stage sufficient to accumulate a threshold amount of food. We perform a qualitative analysis of the solutions, which includes studying positivity and boundedness, existence and local stability of equilibria. For the global dynamics of the system, we discuss an attracting region which is determined by solutions, and the region collapses to the interior equilibrium in the constant delay case.展开更多
文摘The Qingxi Depression, over an area of merely 490 km2, is a petroliferous depositional center within the Jiuxi Basin. Lower Cretaceous source rocks in this depression are a suite of mudstones, dolomitic mudstones and argillaceous dolostones formed in a deep lacustrine environment. Although their distribution area is small, their thickness is sizable. High abundance and favorable types of organic matter provide an important material basis for petroleum generation. The majority of the source rocks in the Qingxi Depression are of maturation conditions for generating significant volumes of petroleum, and with only one peak generation period that commenced in the Neogene. The Himalayan movement results in a northerly overthrusting of the Qilian Mountains nappe to form a series of compressional faults, shear faults and rock fractures, all of which serve as main conduits for petroleum migration from west to east, and, in addition, as the reservoir space of the Qingxi Oilfield. Based on these factors, it is suggested that the future exploration be on the Qingxi low bulge and favorable fracturing zone within this depression.
文摘We propose and study a predator prey model with state-dependent delay where the prey population is assumed to have an age structure. The state-dependent delay appears due to the mature condition that the prey must spend an amount of time in the immature stage sufficient to accumulate a threshold amount of food. We perform a qualitative analysis of the solutions, which includes studying positivity and boundedness, existence and local stability of equilibria. For the global dynamics of the system, we discuss an attracting region which is determined by solutions, and the region collapses to the interior equilibrium in the constant delay case.
