“502”熏显仪器及熏显胶对显现效果影响研究

使用不同的"502"熏显仪器和熏显胶,对汗潜手印的显出率及显出效果进行比较研究。对遗留2 h内的样本和遗留7 d(168 h)后的样本,分别使用MVC?1000熏显仪和FGSP-300型502指纹熏显柜进行熏显,并分别使用北京化工厂公司生产的"502胶"、北京布兰特警用装备有限责任公司生产的"脱胶502试剂"和Foster+freeman公司生产的熏显试剂"Cyanobloom"等3种熏显胶。结果表明:从样本手印熏显后纹线的显出率、清晰程度、薄厚均匀度等分析,MVC?1000熏显仪效果好于FGSP-300型502指纹熏显柜。熏显胶的效果由高到低依次是"Cyanobloom"、"脱胶502试剂"、"502胶"。"502"熏显仪器和熏显胶对汗潜手印的显出率及显出效果影响明显,尤其是对于较为陈旧的汗潜手印效果尤为突出。     

荧光“502”显现潜在手印研究

探究一种新型的荧光“502”用于显现潜在手印的方法.实验对该荧光“502”显现常见客体上潜在手印的效果以及显现手印的灵敏度进行了研究,并比较了这种同步熏显染色的方法与罗丹明6G、Ardrox荧光液、基础黄40二次染色方法显现手印的效果.结果表明,这种荧光“502”显现潜在手印效果较好,用Coherent Tracer激光器激发后,在橙红色护目镜下可以观察到强烈的黄色或橙黄色荧光,显出的手印纹线清晰,与背景反差明显,可以观察到手印纹线上的汗孔.荧光“502”显现潜在手印的方法操作简便,没有后续二次染色的过程,因此不会破坏手印,可以确保纹线及其细节特征的完整性.     

“502”同步熏显染色技术在潜在手印显现中的应用研究进展

新型"502"同步熏显染色技术操作简便,可实现熏显和染色同步进行,同时避免了二次染色对指纹纹线的破坏,有利于现场勘验人员规范化操作。该技术有效的弥补了现有"502"熏显技术的不足,为公安机关实际办案提供了新方法和依据。综合介绍了"502"同步熏显染色技术的优势及发展情况,并对今后的研究趋势进行了展望。     

“502”胶熏显汗潜手印后碱性红14染色新方法研究

研究一种新型的荧光染料碱性红14用于"502"胶熏显手印后染色的方法。用荧光光谱仪对试剂进行光谱学分析,测定了激发光谱和发射光谱,通过考察影响显现效果的最佳配方、应用效果、观察条件、陈旧手印处理方法等因素,初步建立了"502"熏显手印后碱性红14染色的方法。结果表明,0.01 mg/m L碱性红14的乙醇溶液,在激光器绿光波段下激发、橙色护目镜下观察得到强烈的橙黄色荧光手印,显现的手印纹线清晰与背景反差很大,能达到很好的增强效果,在公安实践部门将有较好的应用价值。     

“502”胶熏显后荧光染色增强处理探究

光滑非渗透性客体上汗潜手印经502胶熏显出后,常常需要进行染色来增强处理,本文研究了自制荧光磁性粉及基黄-40乙醇溶液对502胶熏显出的汗潜手印的染色效果,探究基黄-40乙醇溶液的最佳浓度,并与传统染色方法进行对比实验。结果表明,自制荧光磁性粉与基黄-40乙醇溶液对502胶熏显手印均有荧光染色作用,在紫外光激发下增强效果良好,基黄-40乙醇溶液最佳染色浓度为0.5%。     

改进的502胶生产工艺

一、概况 502胶,又称瞬间快速粘合剂,化学名α-氰基丙烯酸乙酯。首先由美国伊斯曼公司发现,并于1959年以Eastman 910胶商品名上市销售。30年来,各国相继进行研究开发,该胶已成为世界六大粘合剂之一,美日两国的年产量均在400吨以上。由于其不需添加其他溶剂和固化剂,使用方便,本身无毒,不致癌,在室温下能粘接钢、铝、玻璃、橡胶、塑料等多种材料,因此已从工业上应用迅速扩展到家庭日常用具的修理粘合,成为人们现代生活中的必需品。我国的年产量在24～30吨左右(1983年统计)。     

“502”胶显现潜在手印增强处理方法研究进展

系统介绍了国内外502胶显现潜在手印增强处理方法,主要包括同步增强方法和二次增强方法,并对其在实际应用中的优缺点进行分析,为公安机关实际办案提供理论依据和技术支持,结合502胶处理手印在实际应用中存在的问题,提出了未来研究的需要,并对以后的研究趋势进行了展望。     

“502”胶有色熏显指纹

用照相的方法来处理"502"胶熏显指纹是一种常见的办法,但如果遇到指纹背景颜色比较浅时,拍照效果就会受到很大影响。介绍了用两种显色剂与"502"胶同步熏显,染色后可以方便更清晰的拍照记录指纹图案。     

Detection of protein deposition within latent fingerprints by surface-enhanced Raman spectroscopy imaging

The detection of metabolites is very important for the estimation of the health of human beings. Latent fingerprint contains many constituents and specific contaminants, which give much information of the individual, such as health status, drug abuse etc. For a long time, many efforts have been focused on visualizing latent fingerprints, but little attention has been paid to the detection of such substances at the same time. In this article, we have devised a versatile approach for the ultra-sensitive detection and identification of specific biomolecules deposited within fingerprints via a large-area SERS imaging technique. The antibody bound to the Raman probe modified silver nanoparticles enables the binding to specific proteins within the fingerprints to afford high-definition SERS images of the fingerprint pattern. The SERS spectra and images of Raman probes indirectly provide chemical information regarding the given proteins. By taking advantage of the high sensitivity and the capability of SERS technique to obtain abundant vibrational signatures of biomolecules, we have successfully detected minute quantities of protein present within a latent fingerprint. This technique provides a versatile and effective model to detect biomarkers within fingerprints for medical diagnostics, criminal investigation and other fields.     

Systematic study of dye loaded small mesoporous silica nanoparticles for detecting latent fingerprints on various substrates

Uniform mesoporous silica nanoparticles (MSNs) with small particle size of ca. 50 nm were fabricated and used as a novel developing agent for latent fingerprints detection. Methylene blue (MB) molecules as a representative dye were loaded in the mesopore of MSNs in order to increase the contrast of the developed latent fingerprints. Both powder and suspension methods composed of MSNs and MSNs@MB were investigated on various substrates, and both of them were able to realize the latent fingerprints development. Moreover, powder method can successfully achieve the detection of the sweat pores (i.e., the typical feature of tertiary structure) of the latent fingerprint, and it has a better effect (i.e., contrast, selectivity and resolution) of latent fingerprints development than suspension methods. In addition, trimethylsilyl (TMS) groups were grafted on the surface of MSNs to increase the hydrophobic nature of particles, but MSNs-TMS@MB had the worse effect of latent fingerprint development than MSNs@MB.     

Fluorescent polymer nanofibers based on polycaprolactone and dansyl derivatives for development of latent fingerprints

This work provides a convenient low-cost strategy for fast fabrication of dansyl-based fluorescent nanofibers for development of latent fingerprints aiming forensic applications. Polycaprolactone (PCL) and dansyl cadaverine (DnsCad) or dansylglycine (DnsGly) nanofibers are prepared by electrospinning technique and characterized by SEM, FTIR, thermal analysis, and fluorescence spectroscopy. The electrospun PCL/DnsCad and PCL/DnsGly nanofibers are fluorescent with greenish blue and yellowish green emission, respectively. Such nanofibers are useful for enhancement of the visual contrast of latent fingerprints on metallic surfaces when exposed to UV light. These findings are particularly important for development of latent fingerprints on cartridge cases.     

黄芩药材的毛细管电泳指纹图谱研究

采用毛细管电泳方法建立黄芩不同产地药材的指纹图谱。考查多种提取方法提取黄芩药材中黄芩苷的提取率;研究运行缓冲液的浓度和酸度、检测波长及分离电压对黄芩药材指纹图谱的影响,得到了优化的测定条件(50mmol/L硼砂缓冲液,pH值7.94,分离电压为20kV,柱上254nm紫外检测)。进行精密度和重现性实验,各共有峰相对峰面积和相对保留时间的RSD均小于5%。最后利用相似度和聚类分析两种方法对10批黄芩药材的毛细管电泳指纹图谱进行分析,结果与实际样品分类相符合。     

Studies on Hypergolicity of Several Liquid Fuels with fuming nitric acids as oxidizers

Hypergolic or self ignition delays of unsymmetrical dimethylhydrazine (UDMH) and several amine fuels, mixed with three fuming nitric acid oxidizers, have been determined, at room temperature, in a highly sensitive “Cup Test” apparatus. Ignition delay (ID) variations have been studied with respect to the chemical structure of fuel, oxidizer composition, and oxidizer-to-fuel (O/F) ratio. Probable preignition reactions and structure-hypergolicity correlations have been suggested. Some non-hypergolic hydrocarbons and petroleum fractions have been hypergolized by addition of UDMH, and ID variations have been studied with respect to UDMH-content in fuel and catalytic additives (ammonium metavanadate, ammonium dichromate, and cuprous oxide) in the red fuming nitric acid oxidizer (RFNA). Increment in UDMH-content improves the hypergolicity of fuels towards RFNA. For example, kerosene + UDMH 60:40 blend ignites with RFNA with a remarkably low ID of 6 ms. However, the catalytic effect of the additive in RFNA varies widely with the fuel-blend composition.     

金属硫蛋白的检测方法研究进展

主要阐述检测金属硫蛋白常用的金属结合法、电化学分析法、蛋白质分析法、色谱、光谱分析法的研究进展,同时指出目前检测金属硫蛋白存在的不足,旨在为检测金属硫蛋白的研究与应用提供参考依据。     

金属硫蛋白的检测方法研究进展

主要阐述检测金属硫蛋白常用的金属结合法、电化学分析法、蛋白质分析法、色谱、光谱分析法的研究进展,同时指出目前检测金属硫蛋白存在的不足,旨在为检测金属硫蛋白的研究与应用提供参考依据。