火焰原子吸收法测定工业硅中的镍

采用火焰原子吸收光谱法,测定工业硅中的杂质镍。讨论并确定了该方法的最佳测定条件。结果表明,镍的检出限为0.00036%,相对标准偏差小于3%,回收率为98%-99%。该方法简便快捷,适合工业硅中镍的测定。     

红矿和赭石中金属元素含量的测定方法研究

建立火焰原子吸收光谱法用于测定矿物药赭石和红矿中微量元素钙、铜、锌、锰、镍、铬、铅的含量的方法.采,甘火焰原子吸收法快速测定各元素的含量.矿物药赭石和红矿中微量元素钙、铜、铬的含量具有显著的差异.火焰原子吸收法可以川于矿物药微量元素的测定.     

中华人民共和国国家标准 工业硫酸汞含量的测定 冷原子吸收分光光度法

1 主题内容与适用范围本标准规定了用无火焰原子吸收分光光度法测定工业硫酸中的汞含量。本标准适用于工业硫酸中汞含量大干0.000002％的测定。 2 方法原理     

工业碳酸钡中碳酸锶含量测定方法的验证

在修订国家标准GB/T 1614-1999《工业碳酸钡》的过程中,按照日本工业标准JIS K 1415-1992《碳酸钡》和国家标准给出的实验条件,用火焰原子吸收光谱法对碳酸锶含量进行了测定。为了验证试验方法的准确性,进行了标准曲线法、标准加入法的测定,同时做了加标回收试验。通过试验验证后,认为火焰原子吸收光谱法测定碳酸锶含量方法准确,测定速度快,回收率在94%～103%,可满足杂质项目检测的基本要求。     

高温镍基合金中锡测定的研究

采用N2O-C2H2火焰原子吸收光谱法进行高温镍基合金中锡含量的测定。考察了锡的最佳测定条件以及线性范围的浓度。在样品测定中对干扰因素进行了综合考虑。该方法灵敏度高、选择性好,操作简便、容易掌握、分析周期短等优点。方法完全适用于高温镍基合金中锡含量的测定,结果令人满意。     

火焰原子吸收法对水中的锰元素含量的测定

文章利用火焰原子吸收光谱法直接测定了水中锰元素的含量。标准溶液的配制选用了标准加入法。研究了仪器的最佳工作条件;实验结果表明利用该方法测定本水样中Mn元素的相对偏差值小于2.3%,检出限为:3.0μg/L,测定范围为:2.5～300μg/L,该方法简单易行,方便准确。     

火焰原子吸收光谱法快速测定车用汽油中的锂

建立有机稀释-火焰原子吸收光谱法测定车用汽油中锂元素的含量的方法。样品经碘-甲苯溶液处理样品,用氯化甲基三辛基铵-甲基异丁基甲酮溶液稀释,火焰原子吸收光谱法进行测定。标准曲线相关系数均≥0.999,加标回收率:91.5%~110.3%,RSD均在5%以内。方法简便、准确、成本低廉,可用于车用汽油中锂元素含量的检测。     

原子吸收光谱法测定锌单标准样品与含锌多金属混合标准样品中锌浓度的探讨

原子吸收光谱法技术发展成熟,已广泛应用于定量测定试样中金属元素。本文采用原子吸收光谱法与电感耦合等离子体质谱法分别对不同的锌单标准样品及含锌多金属元素混合标准样品中的锌进行定量分析。结果显示对于锌的多金属混标,采用火焰原子吸收光谱法进行测定时,往往无法获得较为理想的实验结果,实验值偏离真值。电感耦合等离子体质谱法,干扰少,灵敏度高,采用该方法对相同的标准样品进行测定,实验测定值落在真值范围内。结果表明锌混标中的其他并存金属元素极易对锌的火焰原子吸收光谱法测定结果产生干扰。采用火焰原子吸收光谱法进行锌的标准物质测定时,应尽量使用锌单标准物质。若使用多金属元素混合标准样品,则需采取如螯合萃取等方法以排除干扰。     

镍基合金镀层中镍的快速测定

本文采用原子吸收光谱法测定了含稀土的镍基合金镀层中的镍含量。其特点是灵敏度高,选择性好,数据准确可靠,方法简便快速,具有广泛的使用价值。本文研究建立了在弱酸性介质中,以特征波长232nm作测定波长,镍空心阴极灯为光源,用火焰原子化进行测定镀层中的镍含量。     

微乳液进样火焰原子吸收法测定异辛酸钴中的微量镍,锰

建立了微乳液直接进样火焰原子吸收光谱法测定微量镍、锰的方法,确定了仪器工作条件和稳定微乳液的形成条件,用于异辛酸钴中微量镍、锰的测定,取得了满意的结果。该法具有简便、快速、准确的特点。     

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.     

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。     

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.