DFO与IDO显现手印效果的比较研究

DFO显现法和IDO显现法,都是显现纸张等渗透性客体上的汗液手印的有效方法。但是,实验研究发现,复印纸、白信封纸、报纸和牛皮纸上的汗液手印,用IDO法显现效果都优于DFO法。IDO法不仅手印的显现率高,而且显出的手印纹线更加清晰,可鉴定率也明显高于DFO法。     

浅谈粘性表面汗液手印显现方法

目前显现粘性表面上潜在手印的方法有染色法、悬浮液法、物理显影液法、粘面粉末法、荧光乳浊液显现法、8-羟基喹啉显现剂显现法等。但这些方法在实战中或操作复杂、或适用范围狭窄。通过研究和实践,发现针对胶带粘面上汗液手印,采取活化加膜粉末刷显,操作简单、适用广泛,能提高了胶带粘面上汗液手印的显出率,便于现场勘查中应用。     

DFO、IDO显现纸张上汗液手印灵敏度比较研究

DFO、IDO显现法都是显现纸张等渗透性客体上汗液手印的有效方法。对这两种显现方法的灵敏度进行研究有利于实际应用时的正确选择。实验比较研究发现：不同客体、不同遗留时间及不同次数遗留的手印，IDO显现法的灵敏度都要高于DFO法。牛皮纸、报纸等客体上遗留时间较长、形成次数较多的汗液手印的显现，应优先考虑使用IDO显现法。     

粉末法显现汗液、油脂手印的机理研究

根据粉末法显现汗液、油脂手印的原理,笔者设计了多组对比实验,用三种常用的粉末显现方法对两类共四种不同客体在不同条件下遗留的手印进行显现,并对实际效果进行观察比对分析。结果表明,汗液和油脂对粉末的吸附至关重要,粉末显现法显现汗液、油脂手印的机理就在于液体对固体粉末的吸附。排除磁力、真空力等吸附机理后,可以推断吸附力主要来源于界面张力、液体的毛细作用力、液体的黏性力、范德华力和静电作用力。     

关于粗糙客体物面显现汗潜手印的研究

通过大量的分析实验,讨论、总结了利用荧光技术显现不同条件下、不同粗糙客体上的汗液手印的方法、步骤和操作技巧。由于粗糙客体表面的凸凹不平的特征决定了其汗液手印纹线的不连贯性,造成手印的显现、提取、分析上的困难。在查阅大量相关的学术著作和优秀论文的基础上,本文利用荧光显现的方法来显现、提取粗糙客体物面上的汗液手印。并理论结合实际操作,重点讨论了对于不同客体、不同遗留时间的粗糙客体上的汗液手印在荧光显现中应当遵循的程序、注意事项和不同方法的适用条件。     

基于超声雾化技术显现潜在汗液手印的实验研究

超声雾化技术具有气雾力度均匀、粒度细小、安全可靠、仪器携带方便、容器可反复使用、环境污染小,适用范围广泛等优点。基于超声雾化技术显现了不同渗透性客体上的潜在汗液手印,采用的是茚三酮溶液超声雾化喷射法。实验研究了溶剂和PH值,以及环境温度、湿度对手印显现效果的影响。实验结果表明,茚三酮超声雾化法较好地显现出不同渗透性客体上的潜在汗液手印的细节特征,是对传统溶液法显现手印的有效改进。     

茚三酮超声雾化显现潜在手印研究

采用茚三酮超声雾化技术显现不同渗透性客体上的潜在汗液手印,研究溶剂和PH值,以及环境温度、湿度对手印显现效果的影响。实验结果表明,茚三酮超声雾化法较好地显现出了手印的细节特征,是对传统的溶液法显现手印的有效改进。     

"茚三酮"与"DFO"法显现渗透性客体上的潜在汗液手印研究

在渗透性客体上显现汗液手印 ,除传统的茚三酮法外 ,还有近年来从国外引进的DFO法。本文结合实例 ,比较两种方法的优缺点 ,推介用DFO处理渗透性客体上潜在汗液指纹的方法及注意事项。     

二氧化钛悬浮液法与“502”熏显法显现黑色塑料袋上潜在手印的研究

在详细阐述了"502"熏显法和二氧化钛小微粒悬浮液法显现原理的基础上,探索"502"→二氧化钛悬浮液联用显现技术,试图提高黑色塑料袋上潜在手印的显出率。对黑色塑料袋上普通汗手印、皮脂汗手印和血手印的进行显现实验,结果表明在二氧化钛悬浮液法之前用"502"熏显检材,对二氧化钛悬浮液的显现效果没有明显影响。二氧化钛悬浮液法作为"502"熏显法的补充,能够提高手印显出率,增强手印质量,获得更多的细节特征。     

纸张上陈旧手印的快速显现

在犯罪现场中，经常涉及到各种纸张上手印的显现，以往多是利用茚三酮的丙酮或乙醇溶液显现纸上手印，这种方法显现时间较长，特别是陈旧汗液手印，全部显示约需２—３天，为加速显现可采用熨、烤等方法，但容易使客体普遍着色，影响显现的质量。笔者采用茚三酮的丙酮──乙醚混合溶液或茚三酮的乙醇──乙醚混合溶液显现纸上陈旧汗液手印，显现时间只需１—２小时。现介绍如下。一、原理茚三酮和氨基酸均有一定的溶解性，是显色反应的良好介质。但汗液中含有丰富的脂类物质，极性较低，一般不易被极性较大的物质所渗透。在溶液中加入极性很…     

Spring,River, Flower,Moon, Night

<正>The world premiere of Pearl electrifies Lincoln Center with its heartfelt tribute to one of America’s greatest novelists By Corrie Dosh Asmall girl named Pearl runs and skips along the banks of the Yangtze River, playing with peasant fishermen, mimicking the graceful movements of village girls,     

Candid,Confident, Cooperative

<正>President Xi Jinping's first state visit to the United States in September represented a forthright and forward-looking exchange of views aimed at expanding bilateral cooperation,evident in the issues that were addressed and the results reached.Hotbutton issues such as cybersecurity,investment and the South China Sea were all subjected to discussion during the visit,which will no doubt exert a positive influence     

READY,WILLING,ABLE

<正>The Chinese delegation to the 2015 Special Olympics World Games arrives in Los Angeles on July 21.The group,made up of 126 members,includes 93 athletes at an average age of 21.They compete in sporting events such as track and field,swimming and football.The Special Olympics movement was founded in 1968 to foster the acceptance and inclusion     

Dance,Dance,Dance

<正>China’s dance industry booms while being troubled by market disorder and product piracy Aflock of children led by their teachers swarmed into the Beijing Exhibition Center,the capital’s first large comprehensive exhibition venue built in 1954. They went there to visit the 2011 China Dance Expo.     

Location,Location, Location

Kashgar is China’s portal to Eurasian trade The oasis where the northern and southern routes of the Silk Road converged thousands of years ago remains an important commercial hub owing to one vitally important factor: location.O     

Wet, Wet, Wet

Local residents struggle to cross a street in rain-lashed Guangzhou, Guangdong Province, on May 25. Downpours swept most parts of the southern province from May 22 to 28. Province-wide precipitation averaged 106.8 mm, reaching 226.9 mm in the Pearl River Delta area. Local authorities raised the rain alert to phase three after two people were killed by a landslide in Xingning City on May 22. The heavy rains affected more than 500,000 people in nine cities and counties and incurred direct losses exceeding 115...     

Environment,Ecology,Economy

Not far from the administrative cen-ter of Guiyang, capital of southwest China's Guizhou Province, sits a vast complex, the Guiyang International Eco-Conference Center. Forty percent of its main building is covered by greenery, while the roof supports more than 100 solar panels, which not only power the building but also provide all of its hot wa-ter.     

SMARTER,BIGGER, STRONGER

正List of China’s top 500 companies shows new trends Profitability, innovation and internationalization—these are some of the focuses of the country’s top companies. Seventy years after the founding of the People’s Republic     

Yoga,Pray, Love

<正>Former ELLE editor forgoes the high life in quest of enlightenment following a journey to India If you have seen the movie Eat,Pray,Love,you must remember Liz Gilbert,a writer and the movie’s main character who gives up almost everything and starts a totally new life in her 30s.In today’s material world,how many people would possess the courage to do this for real?Well,51-year-old Yin Yan for one.In 2003,Yin was editor in chief of ELLE     

Ready,Set, Go

正The Chinese people’s passion to run for fun and better health was taken to a new height by the Beijing Olympics. Situated among fascinating architectural structures,Beijing’s Olympic Forest Park is a special place.The 2008 Beijing Olympics organizers was made a wise decision to turn a huge nature reserve in a northern section of the city into a beautiful park open to all. Even on a very hot and humid day in late June, with temperatures