针对6061铝合金难以在化学机械抛光中获得高表面质量的问题，研究了抛光液中氧化剂（H₂O₂）、缓蚀剂（BTA）的质量分数和pH值对表面粗糙度的影响。基于响应曲面法设计实验，采用方差分析（ANOVA）检验各参数对表面粗糙度影响的显著性，分析参数的交互影响，得出抛光液的最佳组分配比。结果表明，6061铝合金的表面粗糙度随着pH值的增大先增大后减小再增大，随着H₂O₂和BTA质量分数的增加先减小后增大。在优选的抛光液参数组合（pH值为9.7，H₂O₂的质量分数为0.57%，BTA的质量分数为1.16%）下，实现最低表面粗糙度S_a 为0.31 nm，获得了近原子尺度的超光滑表面。

雷达辐射源信号识别在实际战场中是对敌制胜的重要手段。为解决人工提取的雷达辐射源信号特征参数不完备、时效性低等问题，基于模糊函数在表征信号内在结构上的独特作用，提出一种结合模糊函数主脊坐标变换的卷积双向长短时记忆网络的识别方法。首先，为放大不同信号间的差异，采用数学思维将主脊切面转换为极坐标域的几何图像，以此作为神经网络的输入；其次，设计卷积神经网络来挖掘二维时频图的特征信息；最后，搭建双向长短时记忆网络对提取到的特征进行分类识别。仿真实验结果表明，所提方法在信噪比为0 dB以上均能保持100%的准确率，即使信噪比为-6 dB时，识别率仍可达93.58%以上，同时也有效缩短了信号分类时间。结果验证了所提方法不仅能提取信号的隐藏抽象特征，还具备良好的时效性和抗噪性。

Fine finishing of tungsten alloy is required to improve the surface quality of molds and precision instruments. Nevertheless, it is difficult to obtain high-quality surfaces as a result of grain boundary steps attributed to differences in properties of two-phase microstructures. This paper presents a theoretical and experimental investigation on chemical mechanical polishing of W–Ni–Fe alloy. The mechanism of the boundary step generation is illustrated and a model of grain boundary step formation is proposed. The mechanism reveals the effects of mechanical and chemical actions in both surface roughness and material removal. The model was verified by the experiments and the results show that appropriately balancing the mechanical and chemical effects restrains the generation of boundary steps and leads to a fine surface quality with a high removal rate by citric acid-based slurry.

中子因具有极强的穿透力被广泛应用于材料与生物试样微观结构检测，但由于中子束强度显著弱于X射线，通常采用聚焦的方式来实现对中子束的有效利用。针对前期基于高性能制造思想研发的金属材质部分回转椭球中子反射镜进行了聚焦和中子小角散射实验测试。结果表明，聚焦中子束的最大强度能够达到漫散射强度的10³，实现了与前端针孔尺寸几乎相等的圆形焦斑。通过远离最佳焦平面的聚焦实验，获得了不同镜心到探测器距离的束流剖面，该束流剖面的半峰全宽与基于几何光学的理论计算值吻合良好，分析了直射中子束和反射中子束的波长分布，中子的反射率达到了60%，峰值强度超过了1 000个计数/像素（0.1 mm×0.1 mm）。以介孔二氧化硅（MCM-41）为标样，获得了中子小角散射的初步结果。结果表明，该中子反射镜具有良好的聚焦性能，能够应用于中子小角散射。

为解决雷达辐射源信号特征评价不够客观和缺乏评价依据等问题，提出一种基于区间模糊原理以及模糊交叉熵和多准则折中法的群体评价方法。建立信噪比分级评价模型，再结合三角模糊数的截集和区间逼近思想将雷达辐射源信号特征的评价体系转化为区间直觉模糊数；基于汉明距离进行寻优，得出信噪比权重，并运用区间直觉模糊加权平均算子集成群决策矩阵，基于熵最大化法计算属性权重；采取多准则折中法和模糊交叉熵实现特征方案排序。仿真实验结果表明，所提方法能够给出与实际情况相一致的特征评价排序方案，并和逼近理想点方法、投影模型方法分析结果基本一致，验证了所提方法的可行性和有效性。

A unique plasma figuring (PF) process was created and demonstrated at Cranfield University for manufacturing extremely large telescopes. The atmospheric pressure processing is faster and more cost-effective than other finishing processes; thus, providing an important alternative for large optical surfaces. The industrial scale manufacturing of thousands of ultra-precision metre-scale optics requires a robust PF machine: this requirement is achieved by making the plasma delivery system (PDS) performance repeatable. In this study, a dedicated PDS for large optical manufacturing was proposed to meet the industrial requirement. The PDS is based on an L-type radiofrequency (RF) network, a power supply, and an inductively coupled plasma torch. However, the complexities of these technologies require an in depth understanding of the integrated components that from the PDS. A smart control system for the modified PDS was created. This novel control system aims to make the characterization process deterministic: by automating the tuning of critical electrical components in the RF network, which is achieved by the use of in-line metrology. This paper describes the main design aspects. The PDS was tested with a good correlation between capacitance and RF frequencies. The robust PDS design enables a stable discharge of plasma with a low deviation of RF signals during the total 15 hours’ test.

Diamond tools play a critical role in ultra-precision machining due to their excellent physical and mechanical material properties, such as that cutting edge can be sharpened to nanoscale accuracy. However, abrasive chemical reactions between diamond and non-diamond-machinable metal elements, including Fe, Cr, Ti, Ni, etc, can cause excessive tool wear in diamond cutting of such metals and most of their alloys. This paper reviews the latest achievements in the chemical wear and wear suppression methods for diamond tools in cutting of ferrous metals. The focus will be on the wear mechanism of diamond tools, and the typical wear reduction methods for diamond cutting of ferrous metals, including ultrasonic vibration cutting, cryogenic cutting, surface nitridation and plasma assisted cutting, etc. Relevant commercially available devices are introduced as well. Furthermore, future research trends in diamond tool wear suppression are discussed and examined.