光度法快速测定钯-钴镀液中的钯

以碘化钾为显色剂，采用分光光度法测定钯钻镀液中的钯含量。介绍了该方法的原理及分析步骤。探讨了测量波长、酸度、碘化钾浓度、抗坏血酸、发色温度等因素对测量结果的影响。在410nm波长下，钯浓度在8—80μ/10mL范围内测得吸光度与钯浓度之间的关系遵守比耳定律。另外，探讨了干扰元素的影响及其消除。加标回收试验结果表明，该方法准确度高，回收率大101．6％。     

锌-铁合金镀液及镀层中锌、铁的快速测定

为了获得耐蚀性良好的锌一铁合金镀层，必须维持镀液中锌、铁含量在一定的工艺范围内。采用EDTA滴定和分光光度相结合的方法测定碱性锌一铁合金镀液中的锌、铁含量，并优选出最佳测量波长。研究了酸度、显色剂浓度、共存组分及干扰元素对测量结果的影响；结果表明：铁在0～6μg／mL范围内遵守比尔定律。该方法简便快速、准确度高能满足实际生产的要求。     

高灵敏度光度法快速测定电镀废水中的痕量钴

采用分光光度法测定电镀废水中痕量钴的含量。介绍了该方法的分析步骤，探讨了测量波长的确定，酸度、显色剂浓度、增溶剂浓度、配合物的抗酸性、EDTA和共存金属离子等因素对测量结果的影响。结果表明，在pH值为3．5－8时，钴与5－Br-PADAP生成紫红色配合物，在595nm吸收波长下，钴浓度在0－12μg/25mL范围内所测吸光度值与钴浓度间的关系遵守比耳定律。该方法准确度高，回收率达96．4％－102．2％。     

碱性锌—钛合金镀液中锌、钴含量的测定

为获得耐蚀性良好的锌－钴合金镀层，必须维持镀液中的锌－钴含量在工艺范围内，采用EDTA滴定和分光光度相结合的方法测定碱性锌－钴合金镀液中的锌、钴含量。介绍了该方法的分析步骤，探讨了测量波长的确定，亚硝酸钠、镀液共存组分、酸度以及铜离子和铁离子等杂质对测量结果的影响。结果表明，在530nm波长下，钴浓度在0－3μg/mL范围内所测吸光度与钴浓度间的关系遵守比耳定律，该方法准确度高，回收率达97％－103.5%。     

电镀废水中微量铜的快速测定

利用铜腙光度测定电镀废水中的微量铜，优选出最佳测量波长，研究了酸度，柠檬酸浓度，显色剂浓度，温度及干扰元素对测量的影响，铜含量在0-25μg/25mL范围内遵守比尔定律，该方法简便，快捷，具有良好的选择性。     

颗粒形状对全散射法测量颗粒物质量浓度的影响

燃煤电厂排放颗粒物作为大气颗粒物主要来源之一受到广泛关注,实现颗粒物质量浓度的精确在线监测意义重大。激光全散射法作为一种常用的颗粒物质量浓度在线监测方法,受颗粒特性影响较大,易造成较大的测量偏差。为探究颗粒形状对全散射法测量的影响,搭建了全散射法测试台架,并采用球形二氧化硅颗粒对测试系统进行标定,标定结果显示,球形二氧化硅颗粒质量浓度与消光程度高度线性相关,相关系数R2>0.99,测量浓度与真实浓度偏差仅为1.8%。进一步采用633 nm与532 nm波长激光分别对3种非球形(棱形、不规则和片状)二氧化硅颗粒进行测试试验。测试结果显示,3种形状颗粒物的质量浓度与消光程度均高度相关,R2均高于0.99;3种形状颗粒物质量浓度的测量值与真实值偏差与颗粒形状及激光波长相关,对比发现,入射波长为633 nm时,不规则、棱形和片状颗粒的质量浓度测量值与真实值的测量偏差分别为16.1%、27.4%和36.6%;入射波长为532nm时,3种颗粒质量浓度的测量偏差分别为4.8%、11.4%和17.4%;颗粒形状一致条件下,532 nm入射波长时的测量偏差明显较小,通过波长的选择可降低颗粒形状变化造成的测量偏差。     

分光光度法测定镀锌白色纯化液中的铬（IV）和铬（Ⅲ）

在硫、磷混酸介质中，以pei花青为还原剂，采用分光光度法测定镀锌白色纯化液中的铬（VI），利用过氧化氢氧化铬（Ⅲ）测定纯化液中的铬（Ⅲ）。阐述了该方法的测量步骤，探讨了测量波长、酸度、反应温度、时间、pei花青用量及共存离子对测量结果的影响。结果表明，当铬（VI）浓度为0-1.04μg/mL时，所测吸光度与铬（VI）间的关系遵守比耳定律。与常用的硫酸亚铁铵滴定法相比，该方法准确度更高。     

镍-钴合金镀液中镍、钴的快速测定

研究了以EDTA作为显色剂，用双波长光度法测定镍一钴合金镀液中Ni^ 与Co^2 质量浓度的方法，选择并确定了测量波长，分析了溶液的pH值、显色剂的用量等对测量结果的影响，实验结果表明，该方法的准确度和精密度较高。     

大量镍中微量钴的快速测定

在醋酸钠—柠檬酸钠缓冲溶液中,钴与亚硝基 R 盐形成可溶性红色络合物,籍以比色测定。采用加入混合缓冲溶液及工作曲线中加纯镍的方法,120毫克镍不     

分光光度法测定药品中对乙酰氨基酚含量

利用亚硝基铁氰化钠试液为显色剂,将分光光度法应用于"对乙酰氨基酚片"中对乙酰氨基酚含量的测定。以纯水做溶剂,在波长为700 nm下有最大吸收,利用分光光度计测定不同浓度溶液的吸光度,绘制标准曲线并对样品进行分析。实验证明,对乙酰氨基酚在3～23μg/mL浓度范围内,吸光度与样品浓度呈良好的线性关系,相关系数为0.9973,回收率在98.5%以上。此测定方法准确、快速、简便,是测定对乙酰氨基酚含量的最佳方法之一。     

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。