水泥路面上加铺沥青混凝土面层的适应性

本文通过引入水泥路面加铺沥青混凝土面层的问题,比较了四种不同的加铺路面方案,通过不同方案所能适应的情况,举出了采用方案四的工程实例,并分析了方案中几个重要问题。     

PQ magic5.0的应用

要改变硬盘分区,通常只能先将硬盘中有价值的资料全部备份出来,然后再对硬盘重新分区、重新格式化。PQ magic 5.0是实现硬盘动态分区和无损分区的上佳选择。Partition—Magic 支持超过20GB 的大容量硬盘,能在 FAT 和 FAT32分区间方便地实现相互转换,并在不丢失资料     

社会互动论视角下的和谐师生关系

社会互动论认为人际互动的实质是以包括语言和非言语暗示在内的“符号”为沟通中介的人与人之间的相互作用。和谐师生关系的建立和发展对教师、学生、师生双方家庭和学校都有重大意义．需要各方共同努力才能使其得以实现。     

Amplitudes, rates, periodicities and causes of temperature variations in the past 2485 years and future trends over the central-eastern Tibetan Plateau

Amplitudes, rates, periodicities, causes and future trends of temperature variations based on tree rings for the past 2485 years on the central-eastern Tibetan Plateau were analyzed. The results showed that extreme climatic events on the Plateau, such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide. The largest amplitude and rate of temperature change occurred during the Eastern Jin Event (343-425 AD), and not in the late 20th century. There were significant cycles of 1324 a, 800 a, 199 a, 110 a and 2-3 a in the 2485-year temperature series. The 1324 a, 800 a, 199 a and 110 a cycles are associated with solar activity, which greatly affects the Earth surface temperature. The long-term trends (>1000 a) of temperature were controlled by the millennium-scale cycle, and amplitudes were dominated by multi-century cycles. Moreover, cold intervals corresponded to sunspot minimums. The prediction indicated that the temperature will decrease in the future until to 2068 AD and then increase again.     

H_∞ Control of a 5th- order Model of Synchronous Generators

1　IntroductionThe control of synchronous generators is one of the most important and widely studiedproblem in the area of power systems control.Such a problem is a non-trivial one,mainlybecause of the highly nonlinear behaviour of synchronous machines.As a matter of fact,their dynamic dramatically changes when passing from a working condition to another.Asa consequence,standard PID-based controllers can not guarantee high performances overthe entire working range.Among the various control a…     

经济网络系统及其发展趋势

网络模型是研究非线性复杂系统的一般方法之一。以网络的数学界定和网络的拓扑性质为基础，提出网络度概念。在网络视角下讨论了人类的经济现象，分别涉及经济网络中的“点”、“线”及“整体结构”的性质，并进一步引伸出经济网络系统的发展趋势。     

聚乙烯醇与顺丁烯二酸酐酯化反应的研究

本文研究了聚合度为1700±5,水解度为88％的聚乙烯醇与顺丁烯二酸酐在二甲基甲酰胺中进行的均相酯化反应,测定了不同反应时间及不同原料摩尔比对酯化度的影响。结果表明该酯化反应属于二级反应,并得出了动力学方程式。