By using freeze-out properties of multifragmenting hot nuclei produced in quasifusion central \(^{129}\hbox {Xe}+^{nat}\hbox {Sn}\) collisions at different beam energies (32, 39, 45 and 50 AMeV) which were estimated by means of a simulation based on experimental data collected by the \(4\pi \) INDRA multidetector, heat capacity in the thermal excitation energy range 4–12.5 AMeV was calculated from total kinetic energies and multiplicities at freeze-out. The microcanonical formulation was employed. Negative heat capacity which signs a first order phase transition for finite systems is observed and confirms previous results using a different method.

中文翻译：

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使用微规范集成体INDRA协作的公式得出的热核负热容量

通过使用准融合中心\（^ {129} \ hbox {Xe} + ^ {nat} \ hbox {Sn} \）在不同的束能量（32、39、45和50 ）碰撞中产生的多片段热核的冻结特性AMeV）是根据\（4 \ pi \） INDRA多功能探测器收集的实验数据通过模拟估算得出的，根据冻结时的总动能和多重性，计算出4–12.5 AMeV的热激发能范围内的热容。出来。使用微规范制剂。观察到负热容标志着有限系统的一阶相变，并使用其他方法确认了先前的结果。