石油醚为主承载液时IDO指纹显现液的性能及应用

在石油醚中添加适量丙酮替代CFC113/HFE7100作为1,2-茚(满)二酮(1,2-indanedione,简称IDO或IND)承载液,考察了该配方对常用纸张和墨迹上指纹的显现性能.结果表明:指纹显现性能无明显差异;常用的中性签字笔、碳素、蓝黑、纯蓝、油性圆珠笔墨迹,以及激光打(复)印件和报纸字迹均不影响指纹显现。     

乙醇为承载液时DFO指纹显现液的性能及应用

以乙醇替代CFC-113或HFE-7100作为承载液,考察了1,8-二氮芴-9-酮（1,8-Diaza-fluorene-9-one,DFO）对常用纸张和墨迹上指纹的显现性能。结果表明：乙醇为承载液时,DFO对常用纸张上指纹的显现效果无明显差异;除油性圆珠笔墨迹外,常用的中性签字笔墨迹、碳素墨迹、蓝黑墨迹、纯蓝墨迹、激光打（复）印件墨迹和报纸墨迹均不影响指纹显现。     

凝胶型DFO指纹显现剂的制备及应用

使用溶胶-凝胶法将常用的指纹显现剂DFO制成凝胶,根据其溶剂挥发慢、扩散难以及立面不流淌的特性,将其试用于打印纸、人民币等渗透性的样品,效果与溶液法相当;在抽屉、门等非渗透性垂直表面,凝胶法的指纹显现效果明显优于传统DFO溶液。     

化学显现及拍照光滑铜表面潜在指纹

介绍了化学显现及拍照光滑铜表面的潜在指纹的方法。     

新型纳米材料在潜指纹显现中的应用研究进展

指纹是人身认定的首选,通过对犯罪现场的潜指纹进行显现和比对,可以确定或排除与案件有关的犯罪嫌疑人.简要介绍了金属纳米材料、金属氧化物纳米材料及无机非金属纳米材料在显现潜指纹中的应用研究现状;重点阐述了量子点纳米材料、稀土纳米材料、免疫分析纳米材料和适配体识别纳米材料的显现原理、合成方法及其在潜指纹显现中的应用研究进展.对存在的问题进行了讨论,展望了纳米材料显现潜指纹的未来发展趋势.     

混合显现液对纸张客体潜在手印显现效果的探究

通过初步实验筛选出0.5％硝酸银乙醇溶液与1％茚三酮乙醇溶液对渗透性客体显现效果最佳,然后配置茚三酮、硝酸银乙醇混合液对牛皮纸、白纸、报纸三种客体表面上遗留的新鲜和陈旧汗潜指印进行显现.结果表明硝酸银、茚三酮乙醇混合显现液能显现纸张等渗透性客体上的新陈汗潜手印,且与单个试剂显现效果比较,混合显现液显现效果优于单个试剂的...     

金纳米颗粒在潜指纹显现中的应用研究进展

开发出适用性更好的潜指纹显现技术是理论界和实务界攻克的难题之一。纳米材料是当今研究潜指纹显现技术的热点之一。与其他纳米材料相比,金纳米颗粒不仅对银染过程具有催化作用,其自身还具有表面等离子体共振和可发出声波信号等特殊性质,因而成为潜指纹显现技术研究的重点对象。本文综述了近十年来基于以上原理开发的主要潜指纹显现技术,并结合金纳米材料在潜在指纹显现领域中的应用现状,对其发展方向进行了展望。     

苯并咪唑型汗潜指纹荧光显现剂的合成

以三苯胺为起始原料,经过酰基化、氧化缩合、亲核取代和季铵化等系列反应得到了荧光单体FM;荧光单体FM在硫代硫酸铵的作用下与丙烯酸(AA)、2-丙烯酰胺-2-甲基丙基磺酸(AMPS)单体发生自由基聚合,得到FM-AA-AMPS三元荧光共聚物潜指纹显现剂LF-1,其对潜指纹具有良好的吸附性能,在350 nm～500 nm范围内都能表现出良好的荧光效果。     

Solvent extraction, separation of uranium (VI) with crown ether

A solvent extraction separation of uranium with a new crown hydroxamic acid 5, 14-N, N′-hydroxyphenyl-4, 15-dioxo-1,5,14,18-tetraaza hexacosane (NHDTAHA) in the presence of cerium, thorium and lanthanides is described. The uranium is extracted with chloroform solution of NHDTAHA and the extract is directly used for GS-AAS measurements. The detection limit is 0.01 ppm with a sensitivity of 20 ng/0.005 absorbance of uranium. The extraction constants of uranium crown hydroxamic acid complexes are determined. The selectivity factors (K_uranyl/Kⁿ⁺_M) for uranium crown hyrdoxamate evaluated by comparing the K_uranyl with the stability constants for competing metal cations (Kⁿ⁺_M) and anions (Kⁿ_A⁻) and were found to be remarkably large. Uranium is preconcentrated and also determined spectrophotometrically. The molar absorptivity is 1.0×10⁴ l⁻¹ mol⁻¹ per cm at 390 nm and system obeys Beer’s law in the range 2.0–30 ppm of uranium. Uranium has been determined in standard and environmental samples.     

聚乙二醇作为溶剂和催化剂载体在有机合成中的应用

聚乙二醇(PEG)作为一种无毒、热稳定性好、可循环利用和便宜易得的绿色溶剂,与传统的挥发性有机溶剂相比具有更好的稳定性。聚乙二醇(PEG)所负载的催化剂有较高的催化活性,且易于实现催化剂的回收利用,已经被普遍应用于有机合成和催化反应中。综述了近十年来聚乙二醇(PEG)作为溶剂参与的化学反应以及在有机合成与化工中负载催化的应用,介绍了这些反应的特点和优势。     

Cyclic ureas as solvents for poly(aryl ether) synthesis

Summary The synthesis of various poly(aryl ethers) and related small molecule compounds were examined using the cyclic urea 1,3-Dimethyl-3,4,5,6-tetrahydro-2(IH)-pyrimidinone (N,N′-dimethylpropylene urea, DMPU) as the solvent. The results showed that generally higher molecular weight or yields were obtained under less stringent conditions, as compared to other common polymerization solvents. The enhancement was most notable for polymerizations involving aryl fluorides with a lower reactivity than conventionally activated dihalide monomers, e.g. ketones, sulfones. Poly(aryl ethers) displayed excellent solubility in DMPU, which was beneficial in the cases where more rigid heterocyclic-aryl ether polymers are formed.     

Preparation and characterization of hyperbranched poly(ether sulfone) and its application as a coating additive for linear poly(ether sulfone)

Hyperbranched poly(ether sulfone) (HPES), a suitable coating additive for improving the rheological properties of linear poly(ether sulfone) (LPES), was easily produced via polymerization of commercially available bisphenol S (A₂ monomer, BPS) and synthesized 2,4′,6‐trifluoro‐phenylsulfone (BB′₂ monomer, TF). During this reaction, fluoro‐ or phenolic‐terminated HPES (F‐HPES or OH‐HPES) could be facilely obtained by controlling the feed mole ratios of the two monomers. The polymerization mode A₂ + BB′₂ was confirmed by analyzing the model compounds and the degree of branching (DB) was calculated systematically. In addition, the synthesized polymers' chemical structures were exhibited by FTIR, ¹H NMR as well as ¹⁹F NMR spectroscopy. Notably, the addition of 1 wt % HPES reduced the melt viscosity and improved the high temperature liquidity of LPES because of its unique spherical shape. Furthermore, the addition of HPES did not have a negative impact on the performance of LPES, which was attributed to the good miscibility between HPES and LPES. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43892.     

关于用R134a制冷剂替代R12制冷剂的应用研究

介绍了国家关于对大气臭氧层有破坏性物质的替代计划,阐述了用Ｒ１３４ａ制冷剂替代Ｒ１２制冷剂的可能性。     

基因传递材料聚羧酸甜菜碱酯的细胞毒性及转染研究

针对阳离子性载体材料在完成DNA转运和释放后形成对细胞正常生长过程的干扰,设计了一种能够在细胞中水解回复到电中性的叔胺型聚羧酸甜菜碱酯(pCB-ester),研究了该聚合物对细胞生长行为的影响,以及初步的基因转染效果。结果表明pCB-ester的细胞毒性远小于经典的体外高效转染材料聚乙烯亚胺(PEI,25 KDa)和其结构类似物聚甲基丙烯酸二甲氨乙酯(pDMAEMA),并在pCB-ester/DNA的N/P大于1/1时能有效包载DNA,显示了初步的DNA转染能力。这种pCB-ester低细胞毒性特性可能与其在细胞中水解形成两性离子,降低与细胞内生物大分子的非特异性相互作用有关。通过优化聚合物结构,有望进一步提高pCB-ester的转染效率,使之成为新一代超低毒性的非病毒基因载体。     

Bis[4(1-methyl-1,2-epoxyethyl)] derivatives of phenyl ether, 1,4-diphenoxybenzene,and bis(4-phenoxyphenyl) ether

The syntheses of three new α-methyl-substituted bis(epoxyethyl) derivatives of phenyl ether, 1,4-diphenoxybenzene, and bis(4-phenoxyphenyl) ether are reported. Improved procedures for preparing 1,4-diphenoxybenzene and bis(4-phenoxyphenyl) ether by the Ullmann method are described. Infrared spectral data for the bisepoxides and their precursors are given, as are some reactions of the bisepoxides.     

Surface Fluorination of Poly(fluorenyl ether ketone) Ionomers as Proton Exchange Membranes for Fuel Cell Application

A series of sulphonated poly(fluorenyl ether ketone) ionomers were successfully fluorinated by the means of direct surface fluorination. Polymer ionomer samples in two different states (membrane and powder) were treated with F₂ gas which is diluted in N₂ in a special reactor. X‐ray photoelectron spectroscopy (XPS) was used to examine the F/C ratios of the fluorinated materials. The results revealed that the fluorination only occurred on the membrane surface and the fluorination degree increased with increasing F₂ concentration in N₂. The membrane subjected to fluorination shows an obviously enhanced oxidative stability. The endurance in a Fenton's reagent of FSPFEK‐P‐28 is longer than 180 min which is two times longer than that of un‐fluorinated SPFEK. The PEM properties and single fuel cell performances were investigated by comparison of un‐ and fluorinated polymer ionomers. The fluorinated membranes demonstrated an enhanced hydrophobic surface property, increased proton conductivities and better single fuel cell performances. Surface fluorination provides a convenient and useful approach to prepare highly proton conductive membrane with long life‐time PEM fuel cell applications.