Detection of visible and latent fingerprints using micro-X-ray fluorescence elemental imaging

Using micro-X-ray fluorescence (MXRF), a novel means of detecting fingerprints was examined in which the prints were imaged based on their elemental composition. MXRF is a nondestructive technique. Although this method requires a priori knowledge about the approximate location of a print, it offers a new and complementary means for detecting fingerprints that are also left pristine for further analysis (including potential DNA extraction) or archiving purposes. Sebaceous fingerprints and those made after perspiring were detected based on elements such as potassium and chlorine present in the print residue. Unique prints were also detected including those containing lotion, saliva, banana, or sunscreen. This proof-of-concept study demonstrates the potential for visualizing fingerprints by MXRF on surfaces that can be problematic using current methods.     

Comparative Analysis of the Chemical Profiles of 3,4-Methylenedioxymethamphetamine Based on Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GC × GC-TOFMS)*

Abstract: The chemical profiling of illicit drugs is an important analytical tool to support the work of investigating and law enforcement authorities. In our work, comprehensive two‐dimensional gas chromatography–time‐of‐flight mass spectrometry (GC × GC‐TOFMS) combined with nontargeted, pixel‐based data analysis was adapted for the chemical profiling of 3,4‐methylenedioxymethamphetamine (MDMA). The validity and benefit of this approach was evaluated by analyzing a well‐investigated set of MDMA samples. Samples were prepared according to a harmonized extraction protocol to ensure the comparability of the chemical signatures. The nontargeted approach comprises preprocessing followed by analysis of variances as a fast filter algorithm for selection of a variable subset followed by partial least squares discriminant analysis for reduction to promising marker compounds for discrimination of the samples according to their chemical profile. Forty‐seven potential marker compounds were determined, covering most of the target impurities known from the harmonized one‐dimensional profiling as well as other compounds not previously elucidated.     

顶空GC／MS法检验血液中的硫化氢

目的建立血液中硫化氢的气相色谱质谱联用分析方法。方法取心血3mL-5mL,置于20mL顶空瓶中,加入1g氯化钠,加3mL-5mL蒸馏水,加入2mol／L盐酸1mL,加盖密封,混匀后于80℃水浴中加热20min。取液上气体0．5mL进样分析。结果在中毒死亡者的心血中检出硫化氢,保留时间参考值为3．6min。结论该方法可用于刑事案件中硫化氢的快速分析。     

酸性黄显现非渗透性客体上血潜手印初步探究

目的建立一种酸性黄显现非渗透性客体上血潜手印的方法。方法制备白色瓷砖、黑色塑料袋、黑色瓷瓶、易拉罐侧面、深色铁质茶叶盒等为客体的捺印手印,配置以酸性黄作为主要成分的染色剂,对其进行固定、染色、漂洗,在多波段光源下观察。结果在440nm激发光源条件下,通过橙色护目镜观察有很强的黄色荧光特征。结论酸性黄显现法具有操作简单、显现效果明显、能排除深色背景干扰的特点,容易推广使用。     

加大旅游扶贫力度 促进桂林“两个建成”

到2020年桂林市全面建成小康社会,基本建成国际旅游胜地"两个建成"目标,是当前和今后一个时期桂林市的首要任务,旅游是桂林的优势产业和支柱产业,把旅游和扶贫工作结合起来,在贫困地区开发旅游业,使贫困人口尽快脱贫致富,是实现"两个建成"的重要举措。本文根据扶贫攻坚的现状和目标任务,论述了旅游开发对扶贫的意义和作用、桂林旅游开发扶贫的条件和优势,进而提出了桂林贫困地区旅游开发扶贫的对策建议。     

打造美食名县 促进“两个建成”

灵川作为大桂林旅游圈的重要组成部分,深度融合本地特色美食资源,提升灵川美食档次,把灵川县打造成美食名县,促进"两个建成"目标实现。     

Infrared Spectra of U.S. Automobile Original Finishes (1998–2000). IX. Identification of Bismuth Oxychloride and Silver/White Mica Pearlescent Pigments Using Extended Range FT‐IR Spectroscopy,XRF Spectrometry,and SEM/EDS Analysis

Bismuth oxychloride (BiOCl) was the first viable synthetic pearl pigment developed 50 years ago. It was only used for a limited time period in automotive paint (model years 1998–2000), serving to produce luster for a single Chrysler black metallic color. Identification of this pigment in an unknown automotive paint can thus facilitate determination of the vehicle of origin. Bismuth oxychloride imparts effects similar to those produced by silver/white mica pearlescent pigments, and such a pigment was used together with bismuth oxychloride in at least one original equipment manufacturer (OEM) basecoat. Silver/white micas are now used primarily in white pearl tricoat systems. This article describes the identification of bismuth oxychloride and silver/white mica pearlescent pigments in automotive finishes using FT‐IR spectroscopy, X‐ray fluorescence (XRF) spectrometry, and SEM/EDS analysis. Data for some cadmium pigments, which were used in automotive paint several decades ago, are also presented as they produce infrared absorptions similar to that of bismuth oxychloride.     

Infrared Spectra of U.S. Automobile Original Finishes (Post – 1989). VIII: In Situ Identification of Bismuth Vanadate Using Extended Range FT‐IR Spectroscopy,Raman Spectroscopy,and X‐Ray Fluorescence Spectrometry

Chrome Yellow (PbCrO₄·xPbSO₄) was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate (BiVO₄·nBi₂MoO₆, n = 0–2), which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability. This paper describes the in situ identification of Bismuth Vanadate in automotive finishes using FT‐IR and dispersive Raman spectroscopy and XRF spectrometry. Some differentiation of commercial formulations of this pigment is possible based on far‐infrared absorptions, Raman data, and elemental analysis. The spectral differences arise from the presence or absence of molybdenum, the use of two crystal polymorphs of BiVO₄, and differences in pigment stabilizers. Bismuth Vanadate is usually not used alone, and it is typically found with Isoindoline Yellow, hydrous ferric oxide, rutile, Isoindolinone Yellow 3R, or various combinations of these.     

论"两个维护"的理论逻辑、历史逻辑与现实逻辑

"两个维护",即坚决维护习近平总书记党中央的核心、全党的核心地位,坚决维护党中央权威和集中统一领导。"两个维护"不是凭空产生的,有其深刻的理论逻辑、历史逻辑和现实逻辑。从理论逻辑来看,"两个维护"是马克思主义政党理论的当代体现,是对党的民主集中制的创造性运用。从历史逻辑来看,"两个维护"是对我们党和国家正反两方面历史经验和教训的深刻总结。从现实逻辑来看,"两个维护"是加强党的政治建设的首要问题,是中华民族伟大复兴的现实需要,是推进伟大斗争的战略选择。深刻理解这三重逻辑的理论意蕴,是深刻把握"两个维护"的极端重要性、以坚决的态度和实际行动做到"两个维护"的基础和前提。