红外光谱法对氨纶中溶剂残存率的快速分析

利用四氯乙烯对干法纺氨纶中残留溶剂进行萃取,采用液体池法进行红外光谱测试,选取特征吸收峰1690 cm-1或1665 cm-1为分析对象,用吸光度的相对峰高进行定量分析,建立了一种用傅里叶变换红外光谱快速定性、定量分析氨纶中溶剂(二甲基甲酰胺或二甲基乙酰胺)残存率的方法。由标准曲线可知:溶剂含量与红外光谱特征峰处吸光度的相对峰高有很好的线性关系,相关系数达0.999以上;样品定量检测的相对标准偏差约为0.4%,加标回收率约为97%;检测效率高,从制样到检测出结果仅需20 min左右。     

分光光度计波长误差的分析

1前言 分光光度计是利用物质对光的选择吸收现象,进行物质定性和定量分析的仪器。光射入物质后被吸收程度的数量关系符合比耳-朗伯定律:式中:A-吸光度;T-透射率;α-吸收系数;c-溶液浓度;L-光程长度;I_0-入射光强度;I-透射光强度。 所谓物质对光的选择吸收,即不同物质具有不同的吸收光谱。因而,分光光度计对物质的定量分析是基于在一定波长下测量吸收值来完成的。此波长大都选在样品的吸收峰位置。由于峰两旁陡坡处吸收值随波长的变化极为迅速,因而波长的误差会造成明显的吸光度误差。如在定性分析时单纯依靠样品     

影响粉尘中游离SiO2含量测定的主要因素

粉尘中游离SiO2含量越高危害越大。在测定过程中,当实验室内温湿度发生变化不符合标准要求时,会对测定的数据产生直接影响。通过红外分光光度法,使用傅立叶变换红外光谱仪进行测定,利用物质对光选择吸收的现象,对物质进行定性和定量分析,记录12.5μm(800 cm-1)处的谱峰吸光度值,并进行计算。结果表明,在不符合温湿度情况下进行实验,得出的波数、吸光度值、峰位、峰强以及峰形均发生变化,从而导致游离SiO2含量数据偏高。为降低测定误差,应使用空调和除湿机等设备,将实验室环境温度控制为18~24℃、相对湿度<50%RH为宜。     

江苏东海有色水晶的品种以及颜色成因分析

东海天然有色水晶主要有紫晶、烟晶、黄水晶.通过在不同的温度下加热水晶,观察加热后的颜色变化,测定不同温度下的吸光度.根据各色水晶吸光度曲线特征及其在不同温度下的吸光度变化,结合原子吸收光谱分析,探讨有色水晶中空穴心的类型和稳定性.     

红外光谱法定量分析高级脂肪腈

IR中,脂肪腈～三氯甲烷溶液在2250cm~-1波数处显示特征的吸收。应用基线法测定其吸光度,可快速、简便地定量分析高级脂肪腈。     

紫外光谱测定天麻中天麻素的干扰影响

用紫外光谱法测量天麻中的天麻素与对照品比较,进而定量分析此方法的干扰影响。结果显示：干扰光谱对天麻素光谱是负影响;相对于对照品天麻素光谱,干扰光谱吸光度绝对值约是天麻素吸光度的37倍,占混合光谱的96％;干扰光谱吸光度与天麻素浓度呈线性关系。     

3种工艺的PTA残渣成分分析

采用高效液相色谱对Eastman、昆仑工程、Invista 3种专利的6种残渣的主要成分进行了定量分析;采用紫外分光光度计对6种残渣的透过率和吸光度进行了分析,作出残渣浓度与吸光度的关系曲线;用吸光度表示残渣其他有色杂质的虚拟总浓度、并拟合成2,7'-DCF定量。比较了3种专利的残渣的共性和差异,为后续技术开发提供依据。     

湿法磷酸副产α型和β型半水硫酸钙的鉴定及定量分析

半水硫酸钙存在α型和β型两种晶型，根据两种晶型的结构差异，采用X射线衍射仪(XRD)、固体核磁共振(SSNMR)、傅里叶红外光谱仪(FTIR)、差示扫描量热法(DSC)对两种晶型进行了测试表征和定量分析，结果表明，SSNMR、FTIR和DSC均可定性区分两种晶型；采用FTIR定量分析两种晶型在混合样中的含量，通过MATLAB软件拟合得出两种晶型混合物中α型半水硫酸钙含量与吸光度的关系模型为y=0.127 5+0.003 4x,通过对比分析混合样品的模型计算值和实际值，验证了该模型的准确性。     

Origin8.0实现聚合物共混物红外光谱定量分析的数据处理

朗伯-比耳定律表明:可通过红外光谱中特征峰的峰高或峰面积对被测混合物的组分进行定量分析。介绍了在Origin8.0中实现红外数据定量分析前的数据处理方法,包括透过率光谱到吸光度光谱的转换、红外光谱数据的可视化、峰拟合以及红外光谱图的导出。     

炭黑吸碘值测试方法研究

本文通过实验与理论推导，对炭黑样品的称样量在吸碘值测试方法中的影响情况进行了定性、定量分析，提出了解决问题的方法。     

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。