In the processes of discrimination between oil-cracked gases and kerogen-cracked gases, Behar and Pinzgofer et al.’s results were adopted in the former researches, in which the ratio of C2/C3 is basically a constant while the ratio of C1/C2 gradually increases in the course of primary cracking of kerogen. Otherwise in the course of secondary cracking of oil, the ratio of C2/C3 increases rapidly while C1/C2 keeps relatively stable. Our study on analogue experiment shows that, whether it is oil or kerogen, in its process of gas generating by cracking, the ratios of C2/C3, C1/C2 or C1/C3 will all be increased with the growth of thermal conditions. In comparison, the ratio of C2/C3, which is affected by genetic type to some comparatively less extent, mainly responds to the maturity of gases, while the value of C2/C3 is about 2, and that of C2/iC4 is about 10, and the corresponding value of Ro is about 1.5%–1.6%. The influence of gas source on C2/C3 is less than that of gas maturity, otherwise C1/C2 (or C1/C3) is obviously affected by cracking matrices. The ratios of C1/C2, C1/C3 of oil-cracked gases are less than that of kerogen-cracked gases, under the condition that the ratios of C2/C3 are similar in value, so are the value of dryness indexes. There exists wide diffidence between this view and the former discrimination method in theory. The analysis of the spot sample indicates that we can apply the above basic view to dealing efficiently with the problem of the discrimination between oil-cracked gas and kerogen-cracked gas.
A model for contact binary systems is presented, which incorporates the following special features: a) The energy exchange between the components is based on the understand-ing that the energy exchange is due to the release of potential, kinetic and thermal energies of the exchanged mass. b) A special form of mass and angular momentum loss occurring in contact binaries is losses via the outer Lagrangian point. c) The effects of spin, orbital rota-tion and tidal action on the stellar structure as well as the effect of meridian circulation on the mixing of the chemical elements are considered. d) The model is valid not only for low-mass contact binaries but also for high-mass contact binaries. For illustration, we used the model to trace the evolution of a massive binary system consisting of one 12M and one 5M star. The result shows that the start and end of the contact stage fall within the semi-detached phase during which the primary continually transfers mass to the secondary. The time span of the contact stage is short and the mass transfer rate is very large. Therefore, the contact stage can be regarded as a special part of the semi-detached phase with a large mass transfer rate. Both mass loss through the outer Lagrangian point and oscillation between contact and semi-contact states can occur during the contact phase, and the effective temperatures of the primary and the secondary are almost equal. 相似文献
1INTRODUCTIONEnrichment of3He and heavy ions(i.e.,Ne,Mg,Si and Fe),characteristic of impulsive?ares,have beenstudied for more than three decades.It is found that they are generally associated with nonthermal energeticelectron-rich events(Reames et al.1988;Reames1999and references therein;Ho et al.2001;Wang et al.2006)and are related to the peculiar ratio of charge to mass(Mazur et al.1996;Reames1999).Althoughthe abundance of3He ions is not correlated with the abundance of heavy ions,s… 相似文献
The economic and environmental consequences of soil nitrogen tests can have significant impacts on agricultural production.
Some of these are explored here. The pre-side-dress soil N-test is evaluated for a hypothetical farmer growing corn at the
ARS Sustainable Agriculture Demonstration Farm site in southern Maryland. For a farmer not currently using a soil N-test,
adoption of this technology can lead to the enhancement of net farm income and the reduction in nitrogen loss to the environment.
This will transpire only if the farmer is currently underestimating nitrogen carryover by more than 25% or applying nitrogen
fertilizer based solely on an expected plateau-yield goal.
Received: 13 February 1997 · Accepted: 13 May 1997 相似文献