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.     

热敏磁票纸表面潜在手印显现方法研究

随着热敏磁票纸的市场应用呈现加速发展的趋势,本文主要研究热敏磁票纸这种较新客体上常见手印的显现方法并对遗留不同时间的潜在手印显现效果进行探讨。使用金粉、磁性粉末刷显,"502"胶熏显,碘熏以及红外加热法和真空镀膜等方法对热敏磁票纸正面潜在手印均能有效显出,得到较清晰连贯纹线;使用金粉刷显、"502"胶熏显后染色对客体反面手印显现可以增强纹线和背景的反差,得到较好显现效果。粉末刷显法、真空镀膜法、碘熏法、红外加热法对于热敏磁票纸上不同遗留时间的潜在手印有较好的显现效果,具有一定的鉴定价值。     

“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%。     

“502”胶熏显后手印染料增强反差技术的研究

本文选取荧光绿、荧光黄II、荧光红G、荧光橘红GG以及龙胆紫等染料针对"502"胶熏显后手印增强反差技术方面进行了较系统的研究。通过查阅相关文献以及大量的科学性实验,本文针对上述染料的理化性质,寻找"502"胶熏显手印染色增强反差的最佳试剂及方法。实验结果表明,浓度为0.5%的荧光黄II乙醇溶液对于玻璃、瓷砖、塑料等非渗透性客体上的"502"胶熏显后的手印有较好的荧光增强效果,同时,荧光黄II乙醇溶液在pH值=4时的荧光效果更佳。本文的研究成果,将对基层的刑事技术人员提供指导和帮助,使得基层的现场勘查和鉴定工作得到很好的开展。     

“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。     

502胶熏显法显现汗液足迹的探究

随着作案分子反侦查意识的不断增强,在刑事案现场勘查中,发现穿鞋灰尘足迹的概率不断减少,但是案件只要发生,在现场的出入口和重点部位就一定会留下足迹,技术人员对汗液足迹进行粉末显现的过程中,由于汗液与粉末之间的作用力,会使得足迹边缘出现粉末堆积现象,这样会使得足迹的尺寸变大,而导致技术人员在分析作案人人身特点时出现错误。因此结合通过"502"胶熏显手印的原理对木质地板上汗液足迹进行熏显,旨在为技术人员在汗液足迹显现中选择科学合理方法提供参考,并为"502"胶熏显足迹方法的深入研究提出新的想法。     

“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。     

“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”胶显现手印技术的研究进展

介绍了"502"胶显现手印技术的发展历史及现状,着重介绍了"502"胶显现手印技术优缺点及其改进方法。     

铝悬浮液及其显现潮湿客体手印初探

银粉刷显手印是基层公安机关中常用的方法,该方法使用方便且成本低,但是银粉颗粒小,易被吸入人体有害健康,显现油脂手印时,很容易"糊底",有一定的背景染色,而且对于雨淋、水浸的物证以及潮湿环境中的手印显现效果较差。本文主要研究的是铝悬浮液的配制以及潮湿客体上手印的显现,并对悬浮液显现和铝粉刷显显现效果进行比较。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。