Dynamics of First-Order Phase Transitions

大卫奥克斯托比得到了理论和 计算化学计划继续他的工作成核 理论 他将使用统计力学技术，主要是密度 泛函方法，研究一阶相的动力学 过渡。 这种转变在许多领域都至关重要， 科学技术 目前研究计划的目标是 开发新的理论方法来预测成核 气-液和液-固相变的速率。 密度 Oxtoby使用的函数方法结合了原子级的相互作用 这在传统的经典理论中是不可能的。 成核 未来三年研究计划的具体目标 年包括：1）更好地了解偶极效应 成核的相互作用; 2）微观和预测方法， 三组分水-油-表面活性剂体系的相图， 产生微乳液; 3）改进的晶体成核理论， 金属合金; 4）蛋白质结晶的新方法及其 与混凝的关系;和5）固体的影响的仔细研究 衬底和电场对晶体成核的影响。 成核在许多科学和技术领域都很重要 包括：1）云中水汽的凝结和冻结; 2） 从熔体中铸造固体金属和金属合金;以及3） 从溶液中生长蛋白质晶体，以确定其 结构 在分子水平上，这些状态变化的机制 还没有被很好地理解，也许最不被理解的方面是 新相位的第一个聚类出现的速率。 这一步， 被定义为成核，通常是形成的速率决定。 这是一个新的阶段，这是奥克斯托比的研究将试图 阐明。

David Oxtoby is supported by a grant from the Theoretical and Computational Chemistry Program to continue his work on nucleation theory. He will use statistical mechanical techniques, primarily density functional approaches, to investigate the dynamics of first-order phase transitions. Such transitions are of central importance in many areas of science and technology. The objective of the current research program is to develop new theoretical approaches to be able to predict nucleation rates for gas-liquid and liquid-solid phase transitions. The density functional approach used by Oxtoby incorporates atomic-level interactions to an extent not possible in traditional classical theories of nucleation. Specific targets of the research program for the next three years include: 1) a better understanding of the effects of dipolar interactions on nucleation; 2) a microscopic and predictive approach to the phase diagrams of three-component water-oil-surfactant systems that produce microemulsions; 3) an improved theory of crystal nucleation in metal alloys; 4) a new approach to protein crystallization and its relation to coagulation; and 5) a careful study of the effects of solid substrates and electric fields on crystal nucleation. Nucleation is important in a number of areas of science and technology including: 1) the condensation and freezing of water vapor in clouds; 2) the casting of solid metals and metal alloys from the melt; and 3) the growth of protein crystals from solution in order to determine their structure. On a molecular level, the mechanism of these changes of state are not well understood, and perhaps the least-understood aspect is the rate at which the first clusters of the new phase appear. This step, defined as nucleation, is often rate-determining for the formation of the new phase, and it is the step which Oxtoby's research will attempt to elucidate.