金纳米棒比色法检测铜离子

一种基于铜氨络离子催化氧化金纳米棒的传感器针对Cu2+实现分析检测。对金纳米棒的刻蚀过程,导致在金纳米棒长径比的变化,引起纵向表面等离子体共振吸收峰的蓝移和溶液颜色的变化。文章报道的无标记Cu2+纳米比色传感器具有较高的灵敏度。此传感器具有较好的灵敏度,实现Cu2+在3×10-8~5×10-7M范围内的可视化检测。最低检出限为2.7 nM。     

苏州医工所提出纳米碳点荧光增强的方法

正近期,中国科学院苏州生物医学工程技术研究所对碳纳米点的相互作用进行实验设计,并获得碳纳米点荧光发射增强方面的相关结果。近年来,荧光碳纳米材料因其优良的水溶性、耐腐蚀性、低毒性、容易制造及低的光漂白等特性而备受关注。荧光碳纳米点尺寸为几个纳米,除了可以用于多色发光成像、葡萄糖检测、纳米TiO 2太阳能电池、Hg2+无标检测、水介质和活细胞内硫化氢及p H值定量测定等,还可用作温度监测。纳米碳点的发光机制探索引起了不少研究者的关注:激发、尺寸,和p H值依赖和非依赖的荧光激发特性在碳纳米点中已经有相关的报道,少量的研究者对碳纳米点与金属、玻璃、滤纸等不同基质之间相互作用影响进行了探索。     

川佛手水热法合成荧光碳纳米点的研究

以中药材川佛手为碳源,利用水热反应合成了荧光碳纳米点,讨论了水热反应时间、水热反应温度及川佛手的用量对水热反应过程的影响,并通过TEM图和荧光光谱图对荧光碳纳米点进行了结构及性能表征。结果表明,反应釜中溶剂水的体积为30 mL的条件下,水热反应时间为3 h,水热反应温度为160℃和川佛手质量为0.5 g时得到的荧光碳纳米点发光效率最高。此法操作简单、成本低,合成出的荧光碳纳米点水溶性好。     

纳米Cu电极的制备及其在电催化还原CO_2反应中的应用

Cu电极较之玻碳(GC)电极,更有利于CO2的电还原反应,而电沉积制备的纳米Cu电极可以进一步提高其电催化还原性能。本文考察了电沉积条件,包括沉积时间、H2SO4浓度、沉积电位、Cu2+浓度等对所制备的纳米Cu电极对CO2电还原反应催化性能的影响。针对该反应优化了纳米Cu电极的制备条件,并用SEM表征了其微观形貌。最后还将制备的纳米Cu电极运用于CO2与环氧丙烷的电合成反应,提高了碳酸丙烯酯的反应产率。     

基于碘诱导的银纳米粒子形态变化检测cu2+

在pH3.6的条件下,Cu2+与I-发生氧化还原反应生成碘单质,融合银纳米粒子。用紫外-可见吸收光谱和扫描电镜对银纳米粒子的进行了表征,建立了定量检测Cu2+含量的方法。该方法的线性范围为5×10-7-5×10-5M,检出限为0.013μM。将此方法用于合成样的检测,回收率在89.0%-108.6%之间。     

多孔碳负载Cu2O/Cu双相催化剂的制备及其在对硝基苯酚还原中的应用

采用溶剂热合成和气氛焙烧后处理方法制备了多孔碳负载的Cu2O/Cu双相纳米晶,并系统探究了该催化剂在对硝基苯酚催化还原中的催化活性。XRD表征表明在空气中焙烧金属有机框架材料Cu-BTC可以得到CuO纳米材料,而在氮气气氛中焙烧Cu-BTC则可以得到多孔碳负载的Cu2O/Cu双相纳米晶材料。论文通过扫描电镜和透射电镜对比了不同条件下制备的铜基催化剂的微观形貌,相对于空气气氛中制备的CuO催化剂,氮气气氛中制备的Cu2O/Cu双相催化剂具有更小的粒径、分散度和高比表面积。对硝基苯酚催化还原实验结果表明, 相对于空气气氛中制备的CuO催化剂,氮气气氛中制备的Cu2O/Cu双相催化剂在对硝基苯酚的还原中具有更高的催化活性。     

一种新型的选择性识别Fe^3＋的荧光传感器

以三聚氰环为识别化点、萘环为荧光基团,合成了一种新型荧光化学传感器.采用红外光谱、质谱、核磁共振对产物进行了表征,并对产物的性能进行了研究.结果表明,所合成的荧光分子在丙酮溶液中能选择性识别Fe<3+,表现出荧光淬灭现象.荧光淬火的程度和溶液的pH有关,其他的金属离子:Na+、Ma2+、Cu2+、Ca2+、Eu3+、Cd2+、pb2+、Ni2+、Ba2+不影响主体化合物的荧光光谱.     

荧光碳点的快速合成及在Hg~(2+)检测中的应用

以葡萄糖为碳源,双氧水为氧化剂快速合成了一种水溶性好、表面含有羧基、羟基的荧光碳点(CDs)。通过红外光谱与荧光光谱对碳点进行了表征,所合成的碳点量子产率为6.92%,发射光谱随着激发波长红移而红移。研究了碳点溶液在不同p H值下的荧光强度,结果表明碳点溶液对p H值没有明显的依赖性,在p H为8的条件下有较高的荧光强度。将合成的荧光碳点应用到金属离子检测中,发现碳点对Hg2+有较明显的荧光淬灭现象,说明碳点可以用于水溶液中Hg2+离子的检测。     

生物质碳量子点对水中金属离子的检测

采用水热合成法成功制备出具有荧光性的稻壳基碳量子点以及衍生的氨基改性的碳量子点(BMA-CQDs、ACA-CQDs),将其作为荧光传感器检测水中不同离子含量。结果表明,DMA-CQDs碳量子点可以成功检测Cd²⁺、Cr⁶⁺、Cu²⁺和Pb²⁺,相关系数均接近0.98。利用碳量子点的选择性荧光淬灭原理,提供了一种有效检测水体中Cd²⁺和Cr²⁺的简单、迅捷、高效率的方法。     

荧光碳点的绿色合成及发光影响因素

本实验以抗坏血酸为前驱体,一锅煮、绿色合成了荧光碳量子点,并考察了合成时间、合成温度对碳量子点发光效率的影响以及碳量子点对不同pH缓冲溶液和常见离子的耐受性。结果表明90℃时加热5 h时该碳量子点的荧光强度最强,不同的pH缓冲溶液对碳量子点的荧光猝灭作用较强,Pb2+、Cr~(3+)、Hg2+、NO2-离子对碳量子点的发光影响不大。     

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。