六氟化铀钢瓶受热时某些部件炸裂原因的分析

一、概述六氟化铀须用钢瓶贮存与运输,使用时以水浴将其蒸出。这类操作应严格保障安全。表面上看蒸出操作不应有什么问题,但在某些实验中曾发生过钢瓶部件的炸裂事故。如用水浴加热一个内装221.75kg UF_6的601钢瓶,当温度稳定在73℃,打开瓶阀时,即发生阀弹簧箱炸裂事故。使在场的操作人员受到严重损害,也给周围环境造成污染。     

时相图特点分类研究及其临床意义

对４４５例各种心脏疾病行门控心血池显像的时相图特点分析归类,并就７型分类与心室功能各项指标、临床心功能状态、常见心血管疾病及心电图检查之间的关系进行对比研究。结果显示：该分型能够较好地与临床心功能分级及常见心脏病的表现相吻合,较好地反映了核医学影像形象、直观、准确表明临床心功能状态的特点,有助于心脏疾病的鉴别诊断。     

串列加速器束流的纵向输运特性分析

本文论述了串列加速器纵向束流光学的分析方法,利用极值方法解决了束团纵向传输中的聚束器的非线性效应,利用此方法可获得束流纵向特性的各有关参数。并对HI-13串列加速器的重粒子脉冲性质进行了分析。     

EM-1发射度仪

本文介绍一台根据双缝法原理研制成功的发射度仪。     

硅铁的穆斯堡尔谱研究

硅铁是有广泛用途的铁合金材料。已报导的用穆斯堡尔谱研究的硅铁合金,大多系含硅量较低的硅铁合金。我们用穆斯堡尔谱学方法研究了一组含硅量较高的硅铁合金,测定了含硅量40％以上的几种不同组分硅铁的穆斯堡尔谱参数,分析和研究不同含硅量样品的穆斯堡尔谱及其与各相的联系。     

高温气冷堆冷却剂杂质对高温合金材料高温性能影响的研究模型分析

高温气冷堆一回路冷却剂中含有的少量CO、H_2、H_2O、CH_4等杂质,这些杂质对高温堆蒸汽发生器用高温合金的高温性能有重要影响。国外在超高温运行工况下冷却剂杂质对高温合金材料性能的影响方面开展了大量研究,由于研究过程中对试验氦气中痕量的杂质含量控制十分困难,致使相关的研究成果分布比较分散,需要对相关的研究模型进行归纳和分析。高温镍铬合金中的铬是被氧化的主要合金元素,而保护性Cr_2O_3层的形成是合金是否被腐蚀的主要决定因素;铬的稳定相图模型和气体组成三元相图模型是两种被广泛应用的理论模型。本文对铬的这两种理论模型研究方法及其应用情况进行比较和分析。     

QCD临界终点与重子数扰动

相对论性重离子对撞的目的之一是寻找量子色动力学（Quantum Chromodynamics,QCD）临界终点（Critical End Point,CEP），实验中测到的净质子数扰动呈现出非单调的行为，这暗示了CEP的存在。本文使用了3味PNJL(Polyakov-loop Nambu-Jona-Lasinio)模型，沿着从实验数据中拟合的化学冻结线，计算了重子数扰动累积量之比C4/C2随对撞能量的变化。结果发现，基于平衡态假设，在对撞能量7.7～200 GeV范围内，随着对撞能量的降低，C4/C2先缓慢下降后上升，这与实验数据一致。这也暗示平衡态假设可以用于探索重离子对撞后系统的演化行为，揭示了相变线跟化学冻结线的关系对观测量的影响非常重要。     

先进裂变堆用铅铋合金固态性能研究进展

铅基快堆由于其长换料周期、高固有安全性、高功率密度等特点在军事、民用领域具有巨大的应用潜力。文章从铅铋合金相图、合金密度和体积变化、固态力学性能三个方面阐述了铅铋合金组织及性能的研究进展。文献显示,合金中Pb、Bi元素配比,主要溶解元素Fe、Cr、Ni,外加元素（Cd、杂质）对LBE抗拉强度、体积变化等产生不同程度影响;凝固冷速影响样品微观组织以及达到最大膨胀量的时间;时效和应变速率影响合金的屈服强度,并提出了铅铋合金需要进一步研究的主要内容。     

微波离子枪离子束光学的数值模拟

用数值模拟方法研究了聚焦离子束系统中微波离子枪的束光学性能，将离子枪看作由源等离子体极和Ｏｒｌｏｆｆ－Ｓｗａｎｓｏｎ透镜组成的双级加速系统，分析了各参对束发射特性的影响。结果展示出引出束光学主要取决于引出导流系数和电势分布，在一定条件下可获得发散度小的离子束。     

Ion microscopy using magnifying ion TRANSPORT systems and position sensitive detectors

Microanalysis by detection of charged particles may be speeded up by several orders of magnitude when position sensitive detectors are used at the focus of a magnifying lens system. Using beam optics calculations a resolution on the sample of 40 × 7 μm² appears possible with available quadrupoles with an acceptance of 0.375 msr selecting particle energy within a 1.2% range. Even submicron resolution may be possible when energy is selected within a 0.3% range. The projection system has an appreciable field of view: sample regions of the order of 1 mm² may be studied simultaneously when appropriate detectors are used.     

On the design of a monolithic 4-bounce high resolution X-ray monochromator

A monolithic monochromator (+n, −n, −m, +m) made of a single block of Ge crystal designed for CoK_α1 radiation was developed and tested numerically and experimentally by means of X-ray diffraction. The advantage of monolithic devices is their mechanical stability and the alignment of such optics is much easier than with polylithic optics, but the development of these devices is rather demanding. The presented monochromator belongs to a group of coplanar in-line devices, which means that the input beam is parallel with the output beam. For the estimation of the spectral and angular properties of a diffracted beam of this monochromator (such as bandpass width, output divergence and input acceptance) we used a numerical approach which we call spectral-angular function. It takes into account both the vertical and the horizontal divergence of the input radiation and uses two-beam X-ray dynamical theory of diffraction. Experimentally, the monochromator was tested by means of X-ray diffraction (synchrotron radiation testing) and the results from this characterization are presented. The influence of the vertical divergence on the spectral distribution of the diffracted beam is discussed and compared with previously published analytical results.     

Design and reality: Continuous-flow accelerator mass spectrometry (CFAMS)

In 2007 we published [1] the design of a novel accelerator mass spectrometry (AMS) system capable of analyzing gaseous samples injected continuously into a microwave plasma gas ion source. Obvious advantages of such a system are drastically reduced processing times and avoidance of potentially contaminating chemical preparation steps. Another paper in these proceedings will present the progress with the development of the microwave gas ion source that has since been built and tested at the National Ocean Sciences AMS Facility in Woods Hole [2]. In this paper we will review the original design and present updates, reflecting our recent encouraging experience with the system. A simple summary: large acceptance ion beam optics design is beneficial to accelerator mass spectrometry in general, but essential to AMS with plasma gas ion sources.     

束流光学设计计算的最优化方法和计算机程序BOOP

描述了最优化技术在带电粒子束流传输系统设计计算中的应用。按照束流传输的矩阵理论和最优化方法，研制了用于束流光学系统优化设计的计算的程序，介绍了程序的特点和使用效果。     

Quality assessment system for curved crystal X-ray optics

Doubly curved crystal X-ray optics provide intense focused monochromatic beams from laboratory X-ray tube sources. These optics are employed in crystallography and X-ray fluorescence systems and may find application to imaging. It is increasingly important to understand how optic defects impact performance for these systems. A simulation model was developed to assess the effects of misalignment and optic defects on system parameters such as intensity, beam size and resolution. Simulation results were compared to optics measurements. Rapid reproducible measurements of optics quality are important both for performing systematic studies of optics defects and for assessing individual optics. A simple operator-independent alignment technique was developed that was also beneficial in ensuring optimal beam intensity in analysis systems. The measurements and simulations were in good agreement and provided insight into essential optics parameters.     

束流光学软件的移植

以束流光学软件的移植为例,介绍BEPCⅡ加速器控制系统调束软件的移植原理、过程、方法及特点.束流光学软件是控制系统核心调束软件之一,目前已经初步移植完毕.离线测试表明,软件原有功能基本具备,应用程序与模拟数据库之间数据读写准确,计算结果与BEPCⅡ束流光学各参数相符.     

Development of a new sample chamber for proton microprobe analysis of mineral samples

We describe a newly developed proton microprobe sample chamber designed for analysis of heterogeneous mineral samples. The instrument features a computer-driven stage and is equipped with novel beam and sample optics, external microscope and filter exchange system. Under the employed optical geometry, axes of beam and sample optics are collinear and normal to the sample surface, an essential aspect allowing high spatial resolution of analyses and accurate micrometer-scale sample and beam positioning. Use of a long working distance in conjunction with integral reflectance mirror are the primary design constraints satisfied for successful development. Based on measurements, the presented proton microprobe is expected to enhance studies requiring effective and easy-to-perform nondestructive microanalytical analysis of minerals.