Nuclear magnetic resonance diagnosis of an anaplastic astrocytoma

A patient presented with an 8-month history of a progressive left homonymous visual field deficit, left hemiparesis, and a left thalamocortical sensory deficit that was not detectable by repeated conventional neurodiagnostic evaluations. Proton nuclear magnetic resonance (NMR) imaging revealed a right parietal lesion characterized by a prolonged T₂ (spin-spin relaxation time). At surgery, the mass proved to be an anaplastic astrocytoma. NMR appears to be more sensitive than x-ray computerized tomography scanning in some patients with malignant gliomas and offers the clinician an additional probe with which to evaluate these patients.     

A nuclear magnetic resonance study of toluene-polyisobutylene solutions. 2. Vrentas-Duda theory

The self-diffusion coefficients of toluene in polyisobutylene have been analyzed using the Vrentas-Duda free volume diffusion model. The diffusion coefficients were determined at different temperatures and concentrations, using the pulsed field gradient nuclear magnetic resonance technique. The data were satisfactorily described by the model and the size of the polymer jumping unit was extracted. Comparisons were made with the Fujita free volume theory and the Fujita free volume parameters were extracted from the Vrentas-Duda free volume parameters. From the diffusion data that now available, it can be concluded that for most polymers the jumping unit is about 1.5 times the polymer monomer molecular weight. The activation energy of the toluene diffusion in polyisobutylene is compared with the activation energies of other penetrants in the same polymer. The diffusion data presented in this work show that the energy per mole required to overcome the attractive forces which constrain a diffusing species to its neighbors should be considered to be zero, in order to be able to extract the free volume parameters (from viscosity and diffusion data) with an acceptable uncertainty. ©1995 John Wiley & Sons, Inc.     

拉氏（Laguerre）双曲型有核圆汇中线性圆列的一些性质

本文推导出拉氏双曲型有核圆汇的一个结论，即：经过在拉氏双曲型有核圆汇ω上的每一个拉氏圆，有且仅有两个线性圆列属于ω，其中的一个属于ｌＩ（α，β），另一个属于ＬＩＩ（α，β）。ｌＩ（α，β）和ｌＩＩ（α，β）均为构成ω的抛物型线性圆列族。     

High spin properties of 124Ba

The ¹²⁴Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and temperature. The Fermi energies determined as a function of angular momentum is used to study the dependence of shell correction on angular momentum using the Strutinsky smoothing procedure. The most important observation is that the shell correction is almost the same for all spins for ¹²⁴Ba. The spin cutoff parameter and the single particle level density parameter are studied as a function of spin and temperature. Constant entropy lines drawn by plotting the excitation energy against angular momentum are found to be roughly at constant energy above the yrast line and are almost equally spaced. It is observed that no yrast traps are present for ¹²⁴Ba.     

Reaction spectroscopy at fragmentation beam energies – recent advances in studies of two-nucleon removal

Final-state-exclusive two-nucleon removal reaction data from fast fragmentation beams can provide a demanding test of the microscopic two-nucleon transition densities calculated from large-basis shell model wave functions. The sensitivity of measured partial cross sections to pairing and other correlations is discussed. It is also suggested that the widths of the momentum distributions of these partial cross sections will exhibit a strong dependence on the final-state of the residue and the projectile structure.     

理论函数法的快扫相关核磁共振谱测量研究

快扫相关核磁共振谱测量可用理论函数法或参考信号法来实现。本文对理论函数法的快扫相关核磁共振作了理论和实验的研究,并把该方法与参考信号的快扫相关核磁共振作了分析比较,其结果为快扫相关核磁共振谱测量工作提供了有用的参考。     

Research and Development of Nuclear Heating Reactors in China

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FirstIdentificationofLevelSchemesinNeutron─richIsotopes141Xe，152Ceand160Sm

ＦｉｒｓｔＩｄｅｎｔｉｆｉｃａｔｉｏｎｏｆＬｅｖｅｌＳｃｈｅｍｅｓｉｎＮｅｕｔｒｏｎ┐ｒｉｃｈＩｓｏｔｏｐｅｓ１４１Ｘｅ，１５２Ｃｅａｎｄ１６０Ｓｍ＊ＺｈｕＳｈｅｎｇｊｉａｎｇ（朱胜江），ＷａｎｇＭｕｇｅ（王牧歌），ＤｅｎｇＪｉｎｇｋａｎｇ（邓景康）...