基于聚类分析对易燃液体塑料容器盖的光谱检验

将光谱分析方法与聚类方法相结合,对38个模拟案件环境的纵火现场助燃剂塑料容器盖样本进行X射线荧光光谱分析,根据元素种类将38个样本分为6组,建立了一种无损快速检验纵火现场物证的光谱分析方法。使用最短距离聚类法,以欧氏距离作为度量区间表示样本间亲疏关系,进行系统聚类分析,同时使用K-Means快速聚类法与t检验验证聚类效果。结果表明,38个样本分为6组时效果最好。并将各类的样本观测点在Fisher判别空间中的分布和位置情况绘出,与使用元素种类进行分类结果一致,为确定火灾案件性质,侦破案件线索提供了理论依据。     

火场PE、PVC检材助燃剂检测的研究

近年来汽油纵火案件逐年增多,国内外对助燃剂的检测也在不断发展~([1～4]).汽油残留物是案件定性和展开调查的重要依据,汽油易挥发、易燃烧,现代家庭高聚物较多,燃烧后成分复杂对检测造成很大干扰.     

GC-MS对刑事案件中汽油残留物的检验

近年来,刑事案件中的纵火案件呈上升趋势,助燃剂的使用屡见不鲜.准确认定助燃剂的种类,既能为确定案件性质提供重要依据,又能为诉讼提供强有力的证据.汽油由于最容易得到,因此成为刑事案件中最常见的助燃剂.     

裂解气相色谱法分析火场燃烧残留物的研究

采用裂解气相色谱法对四种不同木材原样及分别浸渍汽油和柴油的木材燃烧残留物进行了分析研究，结果表明，无论是不同种类的木材还是含有不同助燃剂的同种木材，其燃烧残留物的裂解色谱图都存在明显的差异，通过对火灾现场燃烧残留物裂解色谱分析，可以确定载体木材的种类及木材中是否浸渍过助燃剂汽油或柴油，从而为火灾原因调查中纵火案件的侦破和诉讼提供科学的依据和证据。     

电气线路火灾中铜导线一次短路与二次短路的显微组织特征

对电气线路火灾中铜导线的一次短路与二次短路的显微组织特性进行了对比分析,利用二者之间微结构开头上的差异来分析鉴定火灾的起因,为公安消防部门侦破火灾案件提供了有利的科学证据,可使案件侦破率及破案速度大大提高。因而,将此项工作加以推广有十分重要的意义。与金相显微镜比较,用电镜进行观察分析具有放大倍数连续调节范围大,景深大,分辨率高,同时具有图象更清晰,立体感更明显的特点。     

易燃液体残留物鉴定技术

火灾是危害公共安全和社会发展的主要灾害之一,给人们的生命和财产带来了极大损害。火灾中易燃液体残留物的鉴定是判断火灾性质是人为还是意外的重要技术手段,是调查火灾原因和法庭诉讼的重要依据。本文按照火灾现场易燃液体残留物的提取、检验和数据分析等流程,对国际上统一的鉴定标准、案件鉴定中遇到的问题、当前物证鉴定提出的新要求以及相关科学研究进行了系统介绍,并对该研究领域未来的发展方向进行了展望。     

用SPME/GC-MS方法检验涉火案件中痕量汽油残留物成分

在纵火、爆炸、凶杀等刑事案件中,经常会遇到痕量汽油残留组分的检验与认定。汽油主要由C12以前的烷烃、烯烃、环烷烃和芳香烃化合物组成。由于涉火案件现场中燃烧介质及其中所含汽油的燃烧时间和燃烧程度都不尽相同,那么残留在介质中的汽油组分多少及轻重组分相对含量会产生较     

火场助燃剂检验鉴定的干扰研究进展

火灾是影响公共安全最为常见的灾害之一,而放火更是严重威胁人民群众生命财产安全,属于典型的暴力犯罪.犯罪嫌疑人为了达到有效快速放火的目的,往往使用助燃剂实施放火,因而助燃剂的检验鉴定对于认定火灾性质起着至关重要的作用.然而火场情况复杂,容易对助燃剂物证检验鉴定产生较大干扰.在火灾发生发展的过程中,火场高温热环境会作用于已...     

汽油燃烧残留物标准样品制备及特征组分研究

汽油燃烧残留物的检测往往是纵火案件侦破的关键,对鉴定机构的检验(鉴定)能力有很高的要求。汽油燃烧残留物的鉴定需要已知样品进行比对分析,但目前还没有相应的标准样品可以提供。因此,建立汽油燃烧残留物标准样品有助于对鉴定机构相应的鉴定能力进行培养和考察。本研究以石英砂为燃烧载体,93号汽油为助燃剂,制备汽油燃烧残留物标准样品,对比研究了溶剂法和直接顶空进样法对汽油燃烧残留物的提取效果。气相色谱-质谱法的分析结果表明,汽油在燃烧前后的特征组分存在明显差异,不同的提取方法对检测结果有一定影响,但是特征组分的变化趋势是一致的,取代的芳烃和稠环芳烃等特征组分的鉴别和含量的相对大小可以作为汽油燃烧残留物鉴定的重要判定依据。     

高效液相色谱-串联质谱法同时测定涂料产品中4种有机磷阻燃剂

<正>随着经济的发展和现代科学技术的进步,高分子合成材料被更为广泛和深入地应用于社会各个领域。但是这类材料的可燃性也很强,由此引起的火灾所带来的经济损失和对人身安全造成的伤害也日趋增强。根据欧盟非食品类危险产品快速预警系统的统计,火灾是通报最多的风险类别之一。如何改善高分子合成材料的防火性能,提高其着火点,增强产品的阻燃性能,减小火灾带来的危险性成为越来越多人关注的焦点。因此各国纷纷开展这类材料阻     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.