四甲基联苯胺法检测潜血指纹优化研究

针对传统四甲基联苯胺显现潜血手印应用过程中存在的问题进行深入研究并加以改进。实验对防止血痕扩散以及四甲基联苯胺显现剂中过氧化氢最佳用量进行了探究,并比较了改进前后四甲基联苯胺显现潜血手印效果。结果表明,改进后四甲基联苯胺显现潜血手印效果得到很大提高,而且在原有基础上将适用范围扩大到非渗透性客体;反应速度得到提高的同时简化了操作程序,无需再反复固定血手印,避免了人为因素对血手印的破坏,保证了血手印的原始性与可靠性;显现后的血手印保存时间变长,可供长久使用。     

潜血手印检测及增强方法进展研究

潜血手印是重大案件现场经常出现的一类痕迹物证,有关潜血手印的检测和增强技术一直以来都是法庭科学领域的重要研究内容。有效、合理的应用检测及增强方法对案件的侦破有着举足轻重的作用。根据增强潜血手印所用原理的不同将增强方法划分为光学方法、化学方法和其他方法,并重点介绍了化学方法在潜血手印、潜血痕迹检测、增强中的应用。希望能为公安工作的实际应用以及潜血手印检测及增强技术的发展提供一定的参考依据。     

渗透性客体上汗潜手印与金属遗留印迹联合显现方法研究

通过考察茚二酮手印显现法与金属遗留印迹显现法之间的相互影响以及两种方法对纸张上汗潜手印与金属遗留印迹显现效果的影响,建立汗潜手印与金属遗留印迹的联合显现方法。实验结果表明,经茚二酮手印显现法与金属工具遗留印迹显现法显出的印迹在颜色和细节特征反映上均互不干扰,且先显现汗潜手印、后显现金属遗留印迹是复合印迹联合显现的最佳顺序。该联合显现方法的建立不仅弥补了渗透性客体上金属遗留印迹显现中手印反映不完整的缺点,而且还使手印中微量金属信息得以利用,从而为证明犯罪嫌疑人与金属工具之间关联性提供了更强有力的证据。     

汗潜手印化学显现方法研究及发展

汗潜手印的显现效果直接影响了案件的侦破与证据证明力强弱的推断,最终影响法庭的审判,因此汗潜手印的显现一直是国内外手印专家所研究的重点.本文回顾了汗潜手印常用化学显现法的历史及发展,并对今后汗潜手印化学显现方法的研究发展趋势予以展望.     

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。     

DMAB显现纸张表面潜在手印应用研究

纸张类客体是案件现场中常见的一类检材,其表面潜在手印的显现在物证检验鉴定过程中具有重要的意义。利用氨基酸敏感试剂N,N-二甲基-4-氨基苯甲醛(DMAB)对纸张表面潜在手印进行显现研究,结果表明,当浓度为0.4%时,DMAB对纸张表面潜在手印有很好的显现效果,显现手印在490 nm光源照射时,橙色护目镜下可观察到黄色荧光。该方法显现灵敏度高、显出手印纹线清晰、与背景反差较大,对于遗留30 d的陈旧性手印仍具有良好的显现效果。     

油红O显现潜在手印的影响因素分析

考察了浸泡时间、浸泡液体、溶液储存时间和使用次数对油红O显现不同纸张上潜在手印的效果的影响,证实了浸泡液体和溶液储存时间对手印显现效果影响小,浸泡时间和溶液使用次数对显现效果影响大,优化了油红O显现手印的处理程序,使用该方法处理潮湿客体上的潜在手印应及时使用新配制的溶液进行显现。     

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.     

硝酸银、茚三酮与DFO对常见纸张上新鲜手印显现对比研究

利用硝酸银、茚三酮与DFO这三种化学显现手印的方法,对比探索一下对常见纸张上汗潜手印哪种显现方法更灵敏,显现的质量更好。避免选用错误的显现方法,导致检材上的手印显现质量不高,或者导致检材损坏,不能进行复检。所以需要探索一下这三种方法哪种方法对于常见纸张上新鲜汗液手印的显现更好,有利于公安基层一线更好的使用。     

碘熏显现油手印的研究

在犯罪现场中除了汗潜手印外还存在部分油手印,为了解决基层对油手印显现的难度,提高显现效率,本文利用碘熏法对生活中常见的各种油手印进行显现,得出了在非渗透性客体上的油脂手印以及油质手印中的以花生油和香油为介质的手印有一定的显现效果,对于其他油类手印在各种客体上显现效果不佳的结论。     

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。