《周培德三角剖分不是最小权三角剖分》一文商榷——反例不成立

周培协三角剖分是否能得到最小权三角剖分，周培德在《周培德三角部分不是最小权三角剖分》一文撰写之前已有新的结论，本文还指出《周培德三角剖分不是最小权三角剖分》一文所举反例不成立。     

HIPS-g-MA共聚物对HIPS/PC共混物相容性、形态和拉伸性能的影响

研究了HIPS／PC共混物的相容性及HIPS－MA对HIPS（30）／PC（70）共混物的相容性、形态和拉伸性能的影响。DSC研究结果表明，HIPS／PC共混物中PS的玻璃化转变温度（Tg)不随组成而变化，而PC的Tg随其质量分数的降低逐渐向低温移动，说明HIPS／PC是部分相容体系。通过DSC、扫描电镜形态观察和拉伸性能测试结果发现，当HIPS－g-MA的含量低于7．5％时，共混物的相容性改善不明显，当其含量达到7．5％时，对共混物有明显的乳化作用，说明饱和的界面浓度在7．5％左右。HIPS－g-MA接枝共聚物在HIPS（30）／PC（70）共混物中的增容作用可能是酯交换反应原位生成的嵌段共聚物所致。     

电沉积Ni-W合金镀层的X射线光电子能谱分析

采用X射线光电子能谱（XPS）对电沉积Ni-W合金镀层表面膜进行了分析。研究结果表明，Ni-W合金镀层表面存在一层薄的氧化膜，而钨的氧化作用远大于镍，Ni-W合金镀层中W含量的提高对耐蚀性起决定作用。     

片状陶瓷材料高低温电性能参数的自动检测

由进口电性能仪配上自制的高温系统，计算机自动采集数据，配置成一套高低温电性参数测定装置，该装置的特点是，升温快，炉体小巧，炉芯可更换盛液氮装置，屏蔽良好，等温区长，温工及参数测量精确可靠。     

液相添加剂对PTCR陶瓷电性能的影响

液相添加剂ＡＳＴ（Ａｌ２Ｏ３＋ＳｉＯ２＋ＴｉＯ２）对ＢａＴｉＯ３陶瓷材料电性能的影响很大，随着Ａｌ２Ｏ３含量的增加，材料的电性能降低；ＳｉＯ２、ＴｉＯ２的物理特性对材料电性能影响较大；过量ＴｉＯ２对材料ＰＴＣ效应有重要影响，适当过量ＴｉＯ２含量，可得到性能优良的ＰＴＣＲ陶瓷。     

基于小波变换的医学图象压缩编码

本文研究了医学图象小波变换系数的统计特征。根据医学图象的特点，提出了基于小波变换的医学图象编码方法。实验表明，这种方法具有较好的压缩编码性能，优于JPEG标准。同时，它支持逐次浮现式传输，从而能满足医学图象存储、通信、检索的需要。     

Estimation of the log-normal mean

The most commonly used estimator for a log-normal mean is the sample mean. In this paper, we show that this estimator can have a large mean square error, even for large samples. Then, we study three main alternative estimators: (i) a uniformly minimum variance unbiased (UMVU) estimator; (ii) a maximum likelihood (ML) estimator; (iii) a conditionally minimal mean square error (MSE) estimator. We find that the conditionally minimal MSE estimator has the smallest mean square error among the four estimators considered here, regardless of the sample size and the skewness of the log-normal population. However, for large samples (n > or = 200), the UMVU estimator, the ML estimator, and the conditionally minimal MSE estimators have very similar mean square errors. Since the ML estimator is the easiest to compute among these three estimators, for large samples we recommend the use of the ML estimator. For small to moderate samples, we recommend the use of the conditionally minimal MSE estimator.     

Microfabricated liquid chromatography columns based on collocated monolith support structures

There is great interest today in massively parallel analytical strategies as a way to accelerate the rate of discovery in biological research; among them being 'biochips' and 'laboratories-on-a-chip'. The concept in the 'chip' approach is that minaturization will allow large numbers of operations to be performed in parallel in a small space, as in electronics. Proceeding with the semiconductor analogy, this paper demonstrates that in situ micromachining can be used to simultaneously fabricate millions of micrometer size, particle like structures in multiple liquid chromatography columns on a single wafer. Reduction of this widely used bioanalytical tool to the nanoliter volume, parallel processing, chip format is a significant step toward laboratories-on-a-chip.