一类收敛级数求和的微分方程解法

从微分方程的角度出发 ,分三个方面讨论了一类收敛级数求和问题的具体解法。     

试论苏轼的婉约词

苏轼的婉约词超尘脱俗,别具特色。无论是“似花还似非花”的咏物词,还是“清丽舒徐”的言情词以及高雅的怀古词、赠人词,都“高出人表”,体现了典型的士大夫词风,因而他对婉约词的发展作出了重要贡献。     

Perceptions of Risk and Vulnerability Following Exposure to a Major Natural Disaster: The Calgary Flood of 2013

Many studies have examined the general public's flood risk perceptions in the aftermath of local and regional flooding. However, relatively few studies have focused on large‐scale events that affect tens of thousands of people within an urban center. Similarly, in spite of previous research on flood risks, unresolved questions persist regarding the variables that might influence perceptions of risk and vulnerability, along with management preferences. In light of the opportunities presented by these knowledge gaps, the research reported here examined public perceptions of flood risk and vulnerability, and management preferences, within the city of Calgary in the aftermath of extensive flooding in 2013. Our findings, which come from an online survey of residents, reveal that direct experience with flooding is not a differentiating factor for risk perceptions when comparing evacuees with nonevacuees who might all experience future risks. However, we do find that judgments about vulnerability—as a function of how people perceive physical distance—do differ according to one's evacuation experience. Our results also indicate that concern about climate change is an important predictor of flood risk perceptions, as is trust in government risk managers. In terms of mitigation preferences, our results reveal differences in support for large infrastructure projects based on whether respondents feel they might actually benefit from them.     

模拟混相驱动态的拟四组分模型

通常模拟混相驱动态采用组分模型,由于组分模型求解工作量大,计算速度慢,要求输入的参数较多,而这些参数很难取全取准,同时组分模型不易被油藏工程师所掌握。因此,介绍了一种模拟混相驱动态的模拟模型,该模型是在黑油模型基础上发展起来的拟四组分模型,它兼有黑油模型和多组分模型的某些优点,如黑油模型的稳定性好和计算速度快、组分模型的可模拟凝析气藏和混相驱等;给出了数学模型及各种物理参数以及混相流体性质的处理方法。该模型还以SPE为例进行计算,结果与SPE的结果一致,从而验证了本模型的可靠性。     

水驱砂岩油藏孔喉结构变化的三维网络模拟

以长期水驱实验为基础，建立了等效水驱砂岩储层孔喉结构变化的三维网络模拟模型，结合三维微粒运移机制和有限差分求解方法，得到了长期水驱砂岩油藏孔喉结构变化规律：（1） 冲刷后喉道半径呈增加趋势，喉道半径变化范围变大，极小喉道半径呈微弱减小趋势；（2） 孔隙网络模型中冲刷半径扩大的孔道分布形式与原始孔隙网络结构密切相关，并非所有的大孔道都串联起来贯穿岩芯孔隙网络的两个端面，但入口端和出口端部分大孔道相互连通，形成端面上的大孔道网络群。网络模拟注水结果结合采油井测试，可为注水剖面的调整提供更加可靠的依据。     

特低渗透油藏 CO2 驱室内实验研究

针对大庆外围油田特低渗透油藏剩余油潜力大、井网加密效益差、水驱采收率低等问题，提出了特低渗透油藏 CO2驱技术。通过细管实验和天然岩芯 CO2 驱油实验，确定了 CO2 与高台子油田原油的最小混相压力，评价了特低渗透砂岩油藏 CO2 驱油效果。实验结果表明，CO2 驱可以应用于高台子油田，并取得较好的驱油效果。当天然岩芯空气渗透率为0.58 mD 时，在水驱基础上，气驱可以进一步提高采收率 8% 以上，特低渗透油藏实施 CO2 驱油技术是可行的。     

"男主女从":必须扬弃的等级观——《布洛陀经诗》的性别哲学研究之三

《布洛陀经诗》虽然包含"阴阳合德"等合理因素,但从其宗教神灵观的主要特征,以及在角色定位上的主导思想、在价值评价上的主流意识等方面来看,"男主女从"的等级特征都较为明显。这种等级观体现了壮族性别哲学和壮族传统文化的某些糟粕,是我们在寻求性别和谐发展之道时所必须给予剔除和扬弃的。     

天然岩芯化学驱采收率机理的一些认识

用牛顿流体驱替一定的均质多孔介质系统结果显示，驱油效率由驱替液的毛管数决定。用化学液驱替天然岩芯时，除毛管数以外，还有很多其他因素影响驱油效率。天然岩芯，即使在宏观上是均匀的，在微观上也不均匀；驱替时所得到的效率一般被称为驱油效率，实质上是微观波及效率和驱油效率的乘积。牛顿流体没有弹性，驱替时，体系的润湿性不发生变化，不出现渗吸作用，不形成乳液，孔隙的几何形状不发生变化。但是，用化学液驱替天然岩芯时，由于化学液为粘弹性，体系有润湿性的改变，会出现乳化现象，渗吸作用也会出现。上述因素都会影响驱油效率，尤其是当多种因素同时作用时。分析了极限采收率和经济采收率的区别。很多文章都论述极限采收率，但经济采收率对油田的作用更大。化学驱应考虑上述因素，这对设计、开发、筛选化学剂以及确定驱油体系会是有益的，将深化我们对化学驱机理的认识，促进这方面更深入的研究。     

碱、表面活性剂和聚合物为主的三元复合驱油体系相行为研究

通过研究不同浓度Na2 CO3、KPS存在的条件下复合驱油体系的相行为变化 ,找到了形成中相最佳区的条件 ,揭示了相行为与油水界面张力及表面活性剂在不同相间分配量大小的相关性 ,从临界胶束浓度变化对相态转变机理给予合理解释。     

Floods and Climate Change: Interactions and Impacts

Whether the floods experienced during the last decade in Germany and in other European countries are triggered or worsened by human activities has been the subject of a great deal of debate. Possible anthropogenic activities leading to increased flood risk include river regulation measures, intensified land use and forestry, and emissions of greenhouse gases causing a change in the global climate. This article discusses the latter by reviewing the existing knowledge on the subject. First, the relevance, capabilities, and limitations of climate models for the simulation and analysis of flood risk under aspects of the anthropogenic climate change are described. Special consideration is given here to differences between the "typical" spatial scale of climate models and hydrological flood models. Second, observations of trends in climate variables relevant for river flooding issues are summarized. Special emphasis is put on the Rhine and other German catchment areas. Third, the possibilities of modeling the different parts of the "cascade of flood risk" are summarized, introducing the special features of meteorological, hydrological, and river hydraulic models.