纳滤法处理APT结晶母液的研究

针对离子交换法生产 APT(仲钨酸铵 )现行工艺中结晶母液必须另设辅助流程处理的缺点 ,提出了一种新的工艺流程 ,即用纳滤法从结晶母液中选择性地脱除氯离子 ,避免了氯的积累 ,处理后的结晶母液可直接返回主流程     

基于端元提取的高光谱影像特定目标识别

高光谱遥感影像中特定目标的识别与提取实际上是从背景图像中有效提取所需目标的过程。“纯净”波谱终端单元（端元,Endmember）选择的结果能有效地描述只含有单一纯粹物质的像元点。高光谱处理技术能够基于真实的物理模型进行波谱提取、比较分析、识别目标。结合AVIRIS高光谱影像实例,分析了高光谱遥感影像n维空间里的单形体理论,运用影像灰度值定标可为反射率、最小噪声分离（MNF）、纯净像元指数（PPI）、终端单元选择、n维散度分析、波谱角度度制图（SAM）等高光谱数据处理技术实现对特定目标的识别与提取。     

解决纯滞后系统问题的一种简单方法

把特制的磁性研磨头安装到卧式铣床的主轴上， 就可以进行磁性研磨，介绍研磨机床的结构及加工 原理，计算磁路及电磁线圈的技术参数。     

钨合金白口铸铁共晶碳化物团球化研究

钨白口铸铁成本低,但共晶碳化物呈连续网状分布,脆性大,在承受冲击载荷的工况下使用易断裂,使用范围受到严格限制。研究了Ce、K、Na复合变质处理对其组织和性能的影响,还提出了评价碳化物变质效果的圆度概念。变质处理后,钨合金白口铸铁的共晶碳化物形态发生了显著变化,在常规热处理条件下,共晶碳化物变成了团球状,使之冲击韧性提高了72.2%、耐磨性提高了49.9%。对共晶碳化物团球化机理进行了深入分析,并讨论了共晶碳化物团球化对力学性能和耐磨性能的影响。变质处理的钨合金白口铸铁轧辊使用寿命比高铬铸铁轧辊提高20%以上,生产成本降低30%以上,推广应用变质钨合金白口铸铁具有较好的经济效益。     

从碳酸盐型含钨的泥质铀矿石中提取铀及铀钨分离

本文阐述了从含钨泥质铀矿石中回收铀及铀钨分离的试验研究。对碳酸盐含量高的该种矿石,采用加压碱浸、离子交换分离铀、钨和吸附后溶液全部返回浸出回路的流程,可获得部颁一级品重铀酸铵产品,并使浸出剂碳酸钠的用量大幅度降低。     

高纯超细凹土制备的分散剂筛选分析

采用分散剂协同超声水热法可以同时实现凹凸棒石粘土(下简称凹土)的纯化和超细化。实验比较了六种分散剂制备高纯超细凹土的效果，综合考察认为，六偏磷酸钠为制备高纯超细凹土的最佳分散剂。在六偏磷酸钠协助下，超声水热处理后的凹土粒度d90达4．7μm，白度由原来的45提高到87，X衍射实验表明凹土纯度接近100％。     

纤维复合材料加固混凝土梁纯弯段保护层剥离应力近似计算

针对纤维复合材料 (FRP)加固混凝土梁纯弯段保护层剥离破坏情况 ,基于实用混凝土梁实验研究成果和有限元方法 ,提出一种过高估算剥离应力的方法。该方法表明 ,剥离应力不大。     

On the potential of combining neutron activation analysis and particle induced X-ray emission (PIXE) for micro- and microdistribution analysis of hard metals in human tissues

Tungsten carbide and cobalt are the main components of hard metal alloy while other metals such as chromium, niobium, tantalum, titanium and vanadium are sometimes added in smaller amounts. Exposure to hard metal dusts can induce a lung fibrosis with cobalt playing a major role. In order to provide information on the role that each metal may have in causing this disease, determination of the total content and the distribution of inhaled metals in lung tissue of hard metal workers is of paramount importance. However, samples such as transbronchial biopsy and bronchoalveolar lavage (BAL), often used in the medical diagnosis of pneumoconiosis, only allow for a small amount of material. This calls for sensitive and accurate analytical procedures for microdetermination and distribution of metals in pulmonary tissue and cellular material, such as macrophages. This work proposes a combination of sophisticated analytical techniques such as neutron activation analysis (NAA), currently applied to the determination of the total concentration of more than 30 elements in biological specimens, and PIXE analysis, particularly microPIXE, which has a great potential for microdistribution analysis in small biological samples. Principles and perspectives for the combined use of these techniques for the analysis of human tissue are outlined and discussed. NAA: determination of hard metals in lung tissue are carried out by neutron irradiation (2 × 10¹⁴ neutrons cm⁻² s⁻¹) in the HFR reactor of Petten. After neutron activation, radiochemical separations of ⁶⁰Co, ¹⁸⁷W, ¹⁸²Ta, ⁵¹Cr followed by computer-based high resolution gamma ray spectrometry allow the measurement of these elements in pulmonary tissues with sensitivities ranging from 10⁻⁴ μg (Cr) to 10⁻⁶ μg (W). PIXE: this technique is multielemental and of relatively high sensitivity (μg/g) even in small total sample masses of from 10 to 100 μg, thus allowing the analysis of parts of needle biopsies. Whereas PIXE has been successfully applied to many medical problems, its usefulness is limited in the total samples analysis for cobalt-related hard metal disease, due to the low levels of cobalt in tissue combined with severe element interferences from the generally more abundant metal, iron. Nevertheless, microPIXE, a special variety of the method scanning over the sample with a focussed ion beam of about 2 × 2 μm², could complement the NAA findings in total samples in the sense of achieving a microdistribution analysis of hard metals (including cobalt) in suitable thin tissue sections.The availability of specialized facilities at the JRC such as the powerful HFR reactor (Petten), the NAA laboratories (Ispra) and the microPIXE facility (Geel) could represent a European ‘reference pole’ for the study of metals in tissues of hard metal diseased subjects.     

关于素混凝土与钢纤维混凝土受压韧性的试验研究

钢纤维混凝土是一种性能优良且应用广泛的复合材料，为了比较素混凝土与钢纤维混凝土单轴抗压强度，最大位移以及可吸收变形能的能力。进行了此两类混凝土受压韧性的试验研究。经人工制作试件后，试验在250t级刚性试验机上进行，试验发现，在最大位移能力。残余强度，吸收变形能等方面。与素混凝土比较，钢纤维混凝土具有明显的优势。     

Erosion behavior of SiC–WC composites

Dense silicon carbide (SiC) ceramics were prepared with 0, 10, 30 or 50 wt% WC particles by hot pressing powder mixtures of SiC, WC and oxide additives at 1800 °C for 1 h under a pressure of 40 MPa in an Ar atmosphere. Effects of alumina or SiC erodent particles and the WC content on the erosion performance of sintered SiC–WC composites were assessed. Microstructures of the sintered composites consisted of WC particles distributed in the equi-axed grain structure of SiC. Fracture surfaces showed a mixed mode of fracture, with a large extent of transgranular fracture observed in SiC ceramics prepared with 30 wt% WC. Crack bridging by WC enhanced toughening of the SiC ceramics. A maximum fracture toughness of 6.7 MPa*m^1/2 was observed for the SiC ceramics with 50 wt% WC, whereas a high hardness of 26 GPa was obtained for the SiC ceramics with 30 wt% WC. When eroded at normal incidence, two orders of magnitude less erosion occurred when SiC–WC composites were eroded by alumina particles than that eroded by SiC particles. The erosion rate of the composites increased with increasing angle of SiC particle impingement from 30° to 90°, and decreased with WC reinforcement up to 30 wt%. A minimum erosion wear rate of 6.6 mm³/kg was obtained for SiC–30 wt% WC composites. Effects of mechanical properties and microstructure on erosion of the sintered SiC–WC composites are discussed, and the dominant wear mechanisms are also elucidated.