Investigation on the Performance Characteristics of Two Classes of Energy Conversion Systems

能量转换系统是日常生活及工业生产中的重要设备，其种类繁多，一直是人们关注的对象。近年来，随着能源问题的一再突显，寻找合适新能源成为各国所关心的问题，随之而来如何更加合理利用新能源也同样受到普遍关注，各种利用方法中的能量转换设备同样成为众人焦点。建立新的能量转换系统模型，以有限时间热力学方法对其展开研究，考虑各种模型中的不可逆因素影响，揭示内在机制，分析工作特性，以最优控制理论优化各个参量，提高各个系统的整体性能，以期对实际研究开发应用新能源提供理论依据。这些工作都非常有意义，是值得研究探讨的课题。 本文主要研究流体流动系统和耦合能量转换系统的性能特性。在第一章中，简要介绍有限时间热力学研究的...The energy conversion systems are some of the important equipments that are widely used in daily lives and industry productions, which have various categories and have been noted. In the last years, because of the emergence of the shortage of energy sources, more and more countries have paid attentions to searching new energy sources, and the problems of how to apply new energy sources are univers...学位：理学硕士院系专业：物理与机电工程学院物理学系_理论物理学号：20042403

ULK1 phosphorylates Exo70 to suppress breast cancer metastasis

乳腺癌是威胁女性生命健康的“头号杀手”，而远处转移是乳腺癌患者死亡的主要原因。因此，了解乳腺癌如何发动侵袭和转移，对于有效治疗乳腺癌、延长病人生存期具有重要意义。本研究中，该团队发现ULK1通过结合并磷酸化胞泌蛋白复合体关键亚基Exo70来抑制乳腺癌转移。ULK1对Exo70上Ser47，Ser59和Ser89位点的磷酸化，严重地削弱了Exo70的自身寡聚化和与其它胞外分泌复合体亚基的结合，进而减少了细胞运动伪足形成以及基质金属蛋白酶的分泌，从而抑制乳腺癌细胞的迁移和侵袭。该论文首次揭示了胞外分泌复合体重要成员Exo70在乳腺癌中受到ULK1和ERK1/2的双重磷酸化调控，从而使得乳腺癌细胞可以根据外环境来决定潜伏还是发动侵袭转移，为乳腺癌的治疗提供了新的理论基础。 本论文的通讯作者为占艳艳副教授、郭巍教授和胡天惠教授。医学院博士生毛丽媛、占艳艳副教授、吴斌博士和医学院博士生于强为共同第一作者。【Abstract】Increased expression of protein kinase ULK1 was reported to negatively correlate with breast cancer metastasis. Here we report that ULK1 suppresses the migration and invasion of human breast cancer cells. The suppressive effect is mediated through direct phosphorylation of Exo70, a key component of the exocyst complex. ULK1 phosphorylation inhibits Exo70 homo-oligomerization as well as its assembly to the exocyst complex, which are needed for cell protrusion formation and matrix metalloproteinases secretion during cell invasion. Reversely, upon growth factor stimulation, Exo70 is phosphorylated by ERK1/2, which in turn suppresses its phosphorylation by ULK1. Together, our study identifies Exo70 as a substrate of ULK1 that inhibits cancer metastasis, and demonstrates that two counteractive regulatory mechanisms are well orchestrated during tumor cell invasion.This work was supported by the grants from the National Natural Science Foundation of China (81572589, U1405228, 81472568, and 31770860), the Natural Science Foundation of Fujian grant (2017J06020, 2018J01400, 2017R1036-4, 2017R1036-6, 2016R1034-1, and 2016R1034-4), and the Xiamen Science and Technology grant (3502Z20159013) to Y.-y.Z. and T.H., and National Institute of Health R01 GM111128 to W.G.该论文的研究成果是在国家自然科学基金和福建省基金的资助下，与美国宾夕法尼亚大学和清华大学共同协作完成的

PERFORMANCE CHARACTERISTICS OF A CLASS OF ENERGY CONVERSION COMBINED SYSTEMS AND THEIR PARAMETRIC OPTIMUM ANALYSES

考虑实际能量转换耦合系统中的热漏损失、非理想回热、传热的不可逆性和循环中的内不可逆性,建立一类能量转换耦合系统的较一般模型。分析系统中各主要不可逆性对系统的效率和输出功率的综合影响,计算系统的最大效率和最大输出功率及所对应的性能参数,揭示系统的优化特性。特别是对一些有意义的特殊情况做了详细讨论,直接导出Bejan和Peterson所建立的能量转换耦合系统模型的重要结论,并将有关结果推广应用于太阳能驱动热机系统。The heat leak loss,non-perfect regeneration,irreversibility of heat transfer and endo-irreversibility of the cycle existing in real energy conversion combined systems were considered and a general model of one kind energy conversion combnined systems was established.The synthetic influence of the main irreversibilities on the efficiency and power out- put of the systems was analyzed.The maximum efficiency and power output and the corresponding parameters were calcu- lated.The optimal characteristics of the systems were revealed.Some significant special cases were discussed in detail. The important conclusions in the models of energy conversion combined systems established by Began and Peterson were directly derived.Some relevant results obtained were generalized to apply to solar-driven heat engine systems