A comparative research of two lifting methods: electrostatic lifter and gelatin lifter

Two-dimensional dust shoeprints are often of very high resolution and contain unique features. Lifting these prints in the most effective method may contribute much to preserving these fine details. A research was conducted by experts from Israel and Switzerland to compare gelatin lifters and electrostatic lifters for lifting shoeprints. Several substrates were chosen, and on each material a set of dry dust shoeprints was made. A set of wet prints was made on paper as well. The shoeprints were approximately of the same quality, and the only variable was the nature of the material. On substrates indifferent to the method used, the preferable sequence was tested. Gelatin lifter was superior on most substrates and for wet prints. The superior sequence for using both methods is electrostatic lifting followed by gelatin lifter.     

高速公路化危品槽车突发事故救援对策初探

近年来，随着我国高速公路的不断延伸，参与高速公路化危品槽车突发事故的抢险救援工作已成为各级消防部队面临的一个新课题，本文从分析掌握高速公路化危品槽车突发事故的特点等5个方面入手，就应采取的抢险救援对策进行了深入探讨。     

潜血印迹显现方法研究进展

潜血印迹一般出现在恶性刑事案件当中,能够反映与案件有关的多方面信息,对于同一认定和分析判断案情具有十分重要的作用,这就使得其显现成为现场勘查的一项必不可少的工作。然而,这也正是公安实践工作当中的难点所在。经过多年的实验研究,目前国内外针对于潜血印迹的显现方法主要包括光学显现法和化学显现法。综述了这些常用显现方法的研究进展,并且讨论了每种显现方法在实践工作当中的优势和不足。     

The application of infrared chemical imaging to the detection and enhancement of latent fingerprints: method optimization and further findings

Fourier transform infrared (FTIR) chemical imaging allows the collection of fingerprint images from backgrounds that have traditionally posed problems for conventional fingerprint detection methods. In this work, the suitability of this technique for the imaging of fingerprints on a wider range of difficult surfaces (including polymer banknotes, various types of paper, and aluminum drink cans) has been tested. For each new surface, a systematic methodology was employed to optimize settings such as spectral resolution, number of scans, and pixel aggregation in order to reduce collection time and file-size without compromising spatial resolution and the quality of the final fingerprint image. The imaging of cyanoacrylate-fumed fingerprints on polymer banknotes has been improved, with shorter collection times for larger image areas. One-month-old fingerprints on polymer banknotes have been successfully fumed and imaged. It was also found that FTIR chemical imaging gives high quality images of cyanoacrylate-fumed fingerprints on aluminum drink cans, regardless of the printed background. Although visible and UV light sources do not yield fingerprint images of the same quality on difficult, nonporous backgrounds, in many cases they can be used to locate a fingerprint prior to higher quality imaging by the FTIR technique. Attempts to acquire FTIR images of fingerprints on paper-based porous surfaces that had been treated with established reagents such as ninhydrin were all unsuccessful due to the swamping effect of the cellulose constituents of the paper.     

毒丝本的检验

简要介绍毒丝本的理化性质,并比较了化学显色法、TLC法和分析仪器的条件.     

海滨大戟化学成分研究

目的 研究海滨大戟Euphorbia atoto Forst.地上部分的化学成分组成.方法 采用硅胶柱色谱、Rp-18反相柱色谱、Sephadex LH-20凝胶柱色谱以及重结晶方法进行分离纯化,并根据理化性质及核磁共振波谱和质谱数据鉴定化合物结构.结果 从海滨大戟地上部分95％乙醇提取物中分离得到14个化合物,分别鉴定为mayolene-16(1)、(+)-(R)-脱-O-甲基拉西奥地丁(2)、熊果烷(3)、α-香树脂醇(4)、伪蒲公英甾醇(5)、(3β,24R)-大戟烷-7,25-二烯-3,24-二醇(6)、29-nor-21-α-H-hopane-3,22-dione(7)、Hollongdione(8)、5α-豆甾醇-3,6-二酮(9)、22E,24R-麦角甾烷-7,22-二烯-3β,5α,6β-三醇(10)、菜油甾醇(11)、豆甾醇(12)、β-谷甾醇(13)、芹菜素(14).结论 首次从海滨大戟中分离得到14个单体化合物,其中化合物mayolene-16(1)为新的天然产物.