催化光度法测定痕量锰的研究进展

综述了近年来催化动力学光度法测定痕量锰的进展情况。具体内容包括:催化褪色动力学光度法测定痕量锰,使用高碘酸盐、溴酸盐、氯酸盐、过氧化氢等不同氧化剂氧化有机试剂;催化显色动力学光度法测定痕量锰;协同催化、双指示剂测定痕量锰的催化光度新方法。在每种分析方法中,主要从测定体系、测定条件、灵敏度以及实际应用等方面进行归纳和概述。引用文献33篇。     

新体系锰—高碘酸钾—（4—（2—吡啶偶氮）—间苯二酚）催化动力学光度法…

研究了磷酸氢二钠－氢氧化钠介质中，锰（Ⅱ）催化高碘酸钾氧化ＰＡＲ，使之褪色的反应，测定了其动力学条件，建立了一种高灵敏，高选择性测定痕量锰的新方法，可测０．１１～１．４μｇ／１０ｍｌ范围的锰（Ⅱ），方法的检测限为７．０３×１０＾－１１ｇ／ｍｌ，用于环境水及人发中锰（Ⅱ）的测定，结果令人满意。     

新体系锰－高碘酸钾－［4－（2－吡啶偶氮）－间苯二酚］催化动力学光度法测定痕量锰（Ⅱ）

研究了在磷酸氢二钠－氢氧化钠介质中，锰（Ⅱ）催化高碘酸钾氧化ＰＡＲ，使之褪色的反应，测定了其动力学条件，建立了一种高灵敏、高选择性测定痕量锰的新方法。可测０．０１～１．４μｇ／１０ｍｌ范围的锰（Ⅱ），方法的检测限为７．０３×１０－１１ｇ／ｍｌ，用于环境水及人发中锰（Ⅱ）的测定，结果令人满意。     

新体系催化动力学光度法测定痕量锰(Ⅱ)

以吐温 -80为增敏剂 ,借锰 ( )催化溴酸钾氧化镁试剂的反应 ,拟订了测定痕量锰的新催化动力学光度法。在吐温 -80存在下 ,测定痕量锰的线性范围为 0 .1～ 0 .6μg/L,检出限为 5.3 4× 1 0 -11g/m L。用于测定水样、豆样中锰的含量。     

痕量锰分析中吸附影响的研究

探讨了催化光度法测定痕量锰中克服吸咐影响的方法，试验表明，容器、洗涤液和加样方式的不同均起重要作用。     

痕量锰分析中吸附影响的研究

探讨了催化光度法测定痕量锰中克服吸咐影响的方法，试验表明，容器、洗涤液和加样方式的不同均起重要作用。     

测定痕量锰（Ⅱ）的新催化光度法

本文就存在活化剂氨三乙酸和增敏剂β-环糊精、锰催化高碘酸钾氧化茜素绿反应，拟定了测量痕量锰的新催化光度法，并初步讨论有关的反应机理，本法由于添加了β-环糊精，使得原本应非常灵敏的高碘酸钾氧化茜素绿体系的灵敏度再提高2．5倍，选择性也明显改善，测定锰的线性范围为0—2．4ng／ml，检出限为0．097ng／ml，相对标准偏差0．45％(n=12)，用于测定酒样，大米，糯米中的锰，结果令人满意。     

催化光度法测定痕量锰的研究

在活化剂存在下，锰（Ⅱ）对ＫＩＯ４氧化ＣＡＳ的催化褪色反应，从而测定痕量锰（Ⅱ）。     

利用锰（Ⅱ）的新指示反应催化动力学分析法测定痕量锰

利用锰的新指示反应建立了一个非常灵敏的测定痕量锰的催化动力学分光光度法。它基于在pH9.8的Clark-Lubs缓冲溶液中加热时,铬蓝黑R与过氧化氢反应受锰(Ⅱ)催化吸光度降低的变化。根据Arrhenius方程式计算了催化反应的表观活化能为129.35kJ/mol。本方法Sandell灵敏度为1.07×10~(?)μg/cm~2,0～40ngMn/25ml服从比尔定律。用以测定若干化学试剂中的痕量锰,结果很好。     

用结晶紫的催化氧化动力学方法测定茶叶中的痕量锰

本文研究了锰离子对高碘酸钾氧化结晶紫退色反应的催化效应及其动力学条件,从而建立了痕量锰的催化光度分析方法。测定范围为0～0.5微克/25毫升,检测限为4.7×10~(-10)克/毫升。用本法测定茶叶中的痕量锰取得满意的结果。     

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。