995 resultados para 159-958A


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通过对中能区Ar+Au/Tb/Ag反应中高激发核的发射时标、发射次序、发射机制、核温度、集体运动等衰变特性的研究,提取了轻粒子和中等质量碎片(IMF)的发射时间,IMF发射时间随束流能的升高而变短,发射机制逐渐由相继衰变过渡至多重碎裂。研究了轻粒子和碎片间的发射次序,对高能粒子和碎片,轻粒子先于碎片发射,而低能时,则为碎片先于轻粒子发射。IMF发射成分与角度和碰撞参数有关,前角区来自于弹核碎裂,后角区来自于类靶热核的蒸发。在平面和出平面研究表明,中速粒子和碎片为在平面发射占主导,即存在类转动效应;对轻粒子,转动效应随粒子质量增加而增加;对中速产物均观测到该效应随碰撞参数饿增大而增大。采用几种不同的方法提取了热核的核温度,研究了不同方法之间的区别。

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The Florence Evelyn Willis Goodson Papers consist of newspaper clippings, program notes, photographs, postcards, and lecture notes relating to Mrs. Goodson’s nursing training at McLeod Infirmary in Florence, SC.

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Stereological tools are the gold standard for accurate (i.e., unbiased) and precise quantification of any microscopic sample. The past decades have provided a broad spectrum of tools to estimate a variety of parameters such as volumes, surfaces, lengths, and numbers. Some of them require pairs of parallel sections that can be produced by either physical or optical sectioning, with optical sectioning being much more efficient when applicable. Unfortunately, transmission electron microscopy could not fully profit from these riches, mainly because of the large depth of field. Hence, optical sectioning was a long-time desire for electron microscopists. This desire was fulfilled with the development of electron tomography that yield stacks of slices from electron microscopic sections. Now, parallel optical slices of a previously unimagined small thickness (2-5nm axial resolution) can be produced. These optical slices minimize problems related to overprojection effects, and allow for direct stereological analysis, e.g., volume estimation with the Cavalieri principle and number estimation with the optical disector method. Here, we demonstrate that the symbiosis of stereology and electron tomography is an easy and efficient way for quantitative analysis at the electron microscopic level. We call this approach quantitative 3D electron microscopy.

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Vorbesitzer: Abraham Merzbacher