The Letter describes the investigation of an industrial reaction of N-methylphenylpiperazine and chloro nicotinonitrile, under microwave heating. Besides the formation of the expected 2-(4-methyl-2-phenylpiperazinyl)pyridine-3-carbonitrile (4), extension of the scale leads to unexpected by-products. A specific pathway due to the formation of a reactive ‘ionic alkylating intermediate’ formed in situ under microwave conditions is proposed to explain the results observed.
Electron imaging and Raman spectroscopy are established techniques for viewing and analysing carbon nanotubes. Performing these two techniques usually requires the sample being transferred between a scanning electron microscope(SEM) and a Raman spectrometer. This application note illustrates the advantages of Renishaw^^s structural and chemical analyser(SCA) for imultaneous secondary electron imaging and Raman spectroscopy of single-wall carbon anotubes(SWNTs).
与白炽光源相比,LED 拥有许多优点,包括更低的能耗、更长的寿命,以及更高的灵活性。但是现代 LED 亮度极高,所产生的热量导致了温度升高,这一点已渐渐成为不利因素。 LED 产生的热量会压迫晶粒固着和线焊,从而导致大量模塑化合物发生位移。 热应力和机械应力会削弱线焊的焊接强度,最终导致焊线脱落。 考虑到这些因素,在生产过程中需要小心监控和优化制造工艺,以保障产品能有较长的使用寿命。 Nordson DAGE 焊接强度测试仪提供市场领先的功能,可以应对发光二极管 (LED) 所带来的测试应用的挑战,包括焊线拉力、锡球剪切力、标准晶粒和低轮廓晶粒的晶粒剪切力测试,以及镊钳和晶圆级别的测试。