铜基镀银层中镉含量的测定

将铜基镀银材料在120°C、10%(体积分数)的HNO3中退镀8~15min,然后采用电感耦合等离子体质谱仪(ICP-MS)测定退镀液中镉含量,根据退镀量及所测含量,计算出镀层的镉含量。此方法检出限为0.15mg/kg,实际样品分析的相对标准偏差小于4.8%,样品加权平均回收率为99.2%,能满足镀层有害物质检测的相关规定要求。     

酸洗提纯AlN粉体的研究

氮化铝(AlN)粉体中的金属杂质与氧化是影响其纯度和性能发挥的主要因素,而酸洗是提纯AlN粉体的有效手段.实验采用磷酸(H3 PO4)、硝酸(HNO3)、氢氟酸(HF)和盐酸(HCl)对AlN粉体进行酸洗提纯,主要研究了酸洗过程中酸液的选择与配比对提纯效果的影响.实验结果表明:这四种酸均显著降低了AlN粉体表面的金属杂质含量,而HF和HNO3的混合酸具有更好的提纯效果,特别能降低其中的Na、W、Fe等金属杂质,而且还可通过HF与Al2O3的反应有效去除氧杂质.HF/HNO3酸液的适宜配比为HF:HNO3=2:1,在该条件下酸洗后的AlN粉体中,金属杂质含量均下降到100 ppm以下,氧含量仅为1.2wt%.     

原子吸收法测定热镀锌液中有害元素的含量

提出采用原子吸收法连续测定热镀锌镀液中Fe、Pd、Pb等6种有害元素的含量,从而发现热镀锌厂镀件表面出现麻点、无光泽、发黑问题的原因为镀液中Fe和Pb含量严重超标。该法采用HNO3和HF溶液溶解试样。介绍了最佳的仪器工作条件,并进行了相关的干扰试验。该法快速、准确、回收率高,相对标准偏差为1．7%～2．6％,具有推广价值。     

铜－镍－铬（镍铁－铬）镀层酸性电解退镀液

对５种不同钢铁基体的光亮镀镍、镍铁合金镀层进行退镀。分析了退镀液配方中ＳＴ－１添加剂含量、ｐＨ值、温度、电流密度对退镀速度和基体腐蚀的影响。退镀液的ｐＨ值为３．５～５．５。     

微波消解-火焰原子吸收法测定硅橡胶催化剂中铂的含量

采用微波消解系统消解硅橡胶催化剂,再用火焰原子吸收法测定了其中铂的含量。考察了消解试剂种类、无机酸、共存离子对测定结果的影响及抑制方法。结果表明,采用HNO3+HF或HCl+HF或王水+HF为消解试剂对硅橡胶催化剂进行微波消解时效果好,消解时避免使用H2SO4;为防止消解液爆沸,需进行预消解。常见共存离子K+、Na+、Fe2+、Cu2+、Pb2+、Zn2+、Ca2+、Mg2+、Si对铂含量测定结果的影响很大,无机酸HCl、HNO3及HF对铂含量的测定结果也有一定的影响;采用CuSO4作干扰抑制剂不仅能有效抑制无机酸和共存离子的影响,而且具有明显的增敏作用。此方法的相对标准偏差小于2%,回收率为92.43%~109.05%。     

铜—镍—铬（镍铁—铬）镀层酸性电解退镀液

对５种不同钢铁基体的光亮镀镍，镍铁合金镀层进行退镀。分析了退镀液想方中ＳＴ－１添加剂含量，ｐＨ值，温度，电流密度对退镀速度和基体腐蚀的影响。退镀液的ｐＨ值为３．５－５．５。     

太阳能硅制备过程湿法提纯SiO2的工艺优化

考察了HF质量分数、H2C2O4质量分数、HNO3质量分数、酸浸时间、粒径、液体质量与固体质量的比值(简称液固比,下同)等因素对混酸法提纯SiO2工艺过程的影响,利用电感耦合等离子体发射光谱仪(ICP-OES)、场发射扫描电子显微镜(SEM)进行表征。结果表明,最佳工艺条件为:w(HF)=2%、w(H2C2O4)=3%、w(HNO3)=30%、酸浸时间4 h、粒径100～120目、液固比4∶1、酸浸温度30℃。Fe、Al、Ca、P杂质的去除率分别达到99.99%、14.02%、73.27%、60.00%,经混酸法处理后SiO2中杂质总量的质量分数降至1.465×10-4。     

镁合金基体上镍磷镀层的阳极退除

采用阳极退除方法退除镁合金上化学镀镍磷镀层,研究了退除液成分对镀层退除的作用,对常用的镁合金化学镀镍层的退除工艺（HF＋NaNO3）进行了改进。退镀液中含有一定浓度的F^-,可保护基体不受腐蚀;溶液中的NaNO3对保护膜起破坏作用;生成的保护膜主要为MgF2。     

镀液中金属离子浓度比对化学镀Ni-Co-P薄膜的形貌及磁性能的影响

采用化学镀法在硅基底上直接施镀了Ni-Co-P磁性薄膜,通过调整镀液中金属盐浓度比控制镀层中镍、钴含量,优化薄膜软磁性能。采用SEM、EDAX、XRD和VSM研究了镀液中不同的镍、钴浓度比对薄膜形貌、成分、厚度、镀速、结构和磁性能的影响。结果表明：化学镀Ni-Co-P薄膜由瘤状Ni-Co颗粒组成,镀态的Ni-Co-P镀层由非晶相构成。随着镀液中Co²⁺浓度的增加,镀层中Co元素的含量增多,Ni元素的含量降低,但镀层的镀速减缓,当镀液中Co²⁺含量过高时,施镀非常困难,而镀液中金属盐浓度比对镀层中非金属元素P的沉积量影响不大。Ni-Co-P合金薄膜的饱和磁化强度随着镀层中Co元素含量的增加有上升趋势,矫顽力同时呈现下降趋势。当镀液中c(Ni²⁺)∶c(Co²⁺)=2∶3时,制备的Ni-Co-P镀层软磁性能最好,其饱和磁化强度达到820 emu/cc,矫顽力仅为4 Oe。     

响应面优化废弃ABS镀件退镀工艺研究

采用硫酸-过氧化氢混合液对废旧ABS电镀件进行退镀处理,研究了硫酸浓度、过氧化氢浓度、液固比和浸泡时间对退镀率的影响。在单因素试验的基础上,通过响应面实验设计优化工艺条件。结果表明,四个因素对影响次序为:过氧化氢浓度硫酸浓度液固比时间,硫酸浓度与液固比的交互作用影响显著,最佳的退镀条件是:硫酸浓度(A)为16%,双氧水浓度(B)为4%,时间(C)为2 h,液固比(D)为14. 75,在此工艺条件想退镀率为94. 4%。     

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。