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81.
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was utilized to obtain characteristic mass spectra from three different smokeless powders and six different black powder samples. In these mass spectra, peaks indicative of both the organic and inorganic additive constituents in the gunpowders were observed. TOF-SIMS was able to successfully differentiate between the different black and smokeless gunpowder samples analyzed with the aid of principal components analysis (PCA), a multivariate statistical analysis approach often used to reduce the dimensionality of complex data. TOF-SIMS was also used to obtain information about the spatial distribution of the various additives contained within the gunpowder samples. SIMS imaging demonstrated that that the samples could potentially be characterized by their 2-D structure, which varied from sample to sample. These results clearly demonstrate the feasibility of utilizing TOF-SIMS as a tool for the characterization and differentiation of gunpowder samples for general forensic applications. 相似文献
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83.
Josef Gregory Mahoney 《北京周报(英文版)》2021,64(34):30-31
正The lab leak lie is racist.To be clear,the unscientific surmise that COVID-19 was spread intentionally or unintentionally by a Chinese government laboratory in Wuhan is racist.From the beginning,this lie was an expression of dog-whistle politics,one that has exploited longstanding racial stereotypes,and that has in turn deepened anti-Asian racism in many countries around the world.Stoking the fires The fact that the Donald Trump administration promoted the lab leak lie in 2020 is not surprising.Before the outbreak, 相似文献
84.
George E. Higgins Wesley G. JenningsCatherine D. Marcum Melissa L. RickettsMargaret Mahoney 《Journal of criminal justice》2011,39(1):60