利用溶胶-凝胶法制备SnO_2:P透明导电薄膜的研究

用溶胶-凝胶法制备SnO_2:P透明导电薄膜;探讨P掺杂量、热处理温度、镀膜次数等的对薄膜结构和光电性能的影响。结果表明:SnO_2:P薄膜保持四方金红石结构,随着P掺杂量、热处理温度和镀膜次数的增加,方块电阻先下降后上升;提高热处理温度,可以提高薄膜平整度和致密度;采用提拉法在P/Sn摩尔比为2%时,热处理温度为450℃,镀膜次数为14次时,SnO_2:P薄膜性能最佳,方块电阻为8.9 KΩ/□,可见光平均透过率约为95%;采用旋涂法在P/Sn摩尔比为2%时,热处理温度为450℃,镀膜次数为6次时,方块电阻为4.3 KΩ/□;在相同条件下,采用提拉法制备薄膜光透过率明显高于旋涂法。     

热处理对Sb∶SnO_2透明导电薄膜光电性能的影响

由烧结法制备了5Sb_2O_5·95SnO_2(mol%)陶瓷靶材,以所制靶材利用射频磁控溅射法在石英玻璃基片上制备得到高质量的Sb∶Sn O2(ATO)透明导电薄膜,研究了热处理温度对ATO薄膜的结构和光学与电学性能的影响。结果表明:热处理对ATO薄膜的相结构,结晶质量及性能均有一定的影响。随着温度升高,所制薄膜的晶粒尺寸逐渐长大,方块电阻逐步减小,最小值为9.3Ω/;红外反射率先增大后减小,并在热处理温度为600℃时达到极大值,为89%。薄膜可见光透过率均在80%以上,温度为600℃时最高达到91.3%。     

掺杂Sb对SnO2透明导电膜导电性的影响分析

采用溶胶凝胶法制备透明导电膜,并考察了Sb的掺杂量、热处理温度对薄膜方块电阻以及对薄膜透光率的影响。在SnO_2掺杂1．0%(wt)Sb能显著提高薄膜的电导性,制得的透明导电膜表面电阻率最低为ρ=16×10~(-3)Ω·cm,且薄膜的连续性、致密性好,透光率达到90%以上。     

种子层及掺杂浓度对溶胶-凝胶法制备ZnO∶Al薄膜光电性能的影响

本文采用溶胶-凝胶法以提拉的方式在普通玻璃基底上制备出n型掺杂具有优良光电性能的氧化锌掺铝(AZO)薄膜,并以磁控溅射AZO薄膜为种子层引导液相法所制备AZO薄膜生长.Al掺杂浓度区间为0.25at％～5.00at％.通过X射线衍射仪、场发射扫描电子显微镜、轮廓仪、方块电阻测试仪、霍尔效应测试仪、紫外-可见-红外分光光度计分别研究了薄膜物相、微观结构、膜厚及光电性能,进一步分析了Al掺杂浓度、种子层对薄膜光电性能的影响.结果表明:经10次提拉所制备薄膜可见光透过率85％以上.Al掺杂浓度、种子层的引入对AZO薄膜的光电性能有重要影响.无种子层时,掺杂浓度为0.50at％的AZO薄膜在5％ H2、95％N2还原气氛下于550℃保温60 min得到最优电学性能,方块电阻约为166 Ω/□,电阻率约为1.99×10-3 Ω·cm;预镀AZO种子层所制备薄膜方块电阻下降到约42Ω/□,电阻率下降到约7.56×10-4Ω·cm.     

SnO2:Sb透明导电薄膜的制备及光电性能

采用溶胶–凝胶法在玻璃基底上制备了Sb掺杂SnO2（SnO2：Sb）透明导电薄膜。研究了Sb掺杂量、镀膜次数、热处理温度对SnO2：Sb薄膜结构和光电性能的影响,利用X射线衍射仪、Fourier变换红外光谱仪、扫描电子显微镜、四探针电阻仪、分光光度计对薄膜样品进行表征。结果表明：SnO2：Sb薄膜为四方相金红石结构;薄膜结构平整、致密,膜厚与镀膜次数基本成线性关系;在Sb掺杂量为10%,镀膜8次的条件下,薄膜具有最佳的光电性能,方块电阻达105/□;在玻璃上镀SnO2：Sb薄膜后,近红外波段透过率下降显著,由90%降到5.5%,在可见光波段略有降低,仍保持了较高透过率。     

SnO_2/RGO复合光阳极的制备及其对染料敏化太阳能电池性能的影响

采用原位化学法合成不同质量比的SnO_2/还原氧化石墨烯(RGO)纳米复合材料,通过溶胶-凝胶法制得SnO_2/RGO纳米复合薄膜光阳极。经N3染料浸渍,与Pt对电极,I~-/I_3~-电解质组装成染料敏化太阳能电池(DSSC)。对SnO_2/RGO纳米复合薄膜光阳极结构进行分析,通过伏安特性曲线分析了电池的光电性能。结果表明:石墨烯有利于提高SnO_2基DSSC的光电性能。当GO与SnCl_2·2H_2O的质量比为0.20时,电池的性能最优,短路电流密度(J(sc))和开路电压(U_(oc))分别达到15.56 mA/cm~2和0.56 V,光电转换效率为4.58%。并研究了SnO_2/RGO复合材料对光阳极的电子传输和光电转换效率的影响机制。     

射频反应磁控溅射制备的SnO_2及SnO_2:F薄膜结构与透明导电性能

以Sn和Sn+SnF_2为靶材,采用射频(RF)反应磁控溅射法在150℃不同O_2流量下制备了厚度约为300 nm的SnO_2和SnO_2:F薄膜。通过X射线衍射、Hall效应测试系统和紫外–可见分光光度计研究了两种薄膜的结构和透明导电性能。结果表明:随O_2流量增加,SnO_2薄膜由非晶变为多晶,择优取向从(101)面过渡到(211)面,薄膜电阻先减小后增大,平均透光率逐渐上升。随O_2流量增加,SnO_2:F薄膜结构与透明导电性能的变化规律与SnO_2薄膜类似,SnO_2:F薄膜的择优取向依次为(002)、(101)和(211)面,由于F掺杂,SnO_2:F薄膜的载流子浓度和迁移率明显增加,电阻率降低,同时平均透过率有所提高。目前,在合适的O_2流量下,SnO_2:F薄膜可达到的最低电阻率为4.16×10~(–3) ?·cm,同时其平均透光率为86.5%。     

热处理工艺对溶胶-凝胶法制备ZnO:Al薄膜光电性能的影响

采用溶胶-凝胶法以提拉的方式在普通玻璃基底上制备出ZnO:Al(AZO)薄膜。通过X射线衍射仪、场发射扫描电子显微镜、方块电阻测试仪、Hall效应测试仪、紫外-可见-红外分光光度计研究了薄膜物相、微观结构、光电性能;分析了不同热处理方式对于薄膜光电性能的影响。结果表明:经10次提拉所制备薄膜可见光透过率85%左右。热处理工艺的选择对于提升AZO薄膜的电学性能至关重要,相比于空气气氛和真空下的热处理,采用具有还原性的5%H_2和95%N_2的混合气氛热处理得到了具有最好电学性能的AZO薄膜。在550℃还原气氛下保温60 min得到薄膜方块电阻约为300Ω/□,电阻率约为3.3×10~(-3)Ω·cm。     

膜厚与紫外光辐照对反应溅射法制备的F掺杂SnO_2薄膜结构与光电性能的影响

以Sn+SnF_2为靶材,在衬底温度为150和300℃通过反应磁控溅射法制备了厚度为20～400 nm的F掺杂SnO_2(FTO)薄膜,并通过紫外光(UV)辐照对2种厚度(20和240nm)的样品进行了后处理,研究了膜厚和UV辐照时间对薄膜结构与透明导电性能的影响。结果表明:随着膜厚或衬底温度的增加,FTO薄膜结晶度提高,但择优取向保持为(211)面;与此同时,薄膜中压应力增大,而导电性能下降。随着膜厚的增加,薄膜透光性先降低后增加,而其禁带宽度(E_g)先明显增加后趋于稳定。增大衬底温度可增大薄膜的透光性和E_g。UV辐照可明显提高薄膜的载流子浓度,从而增强薄膜的导电性能,但对薄膜的透光性无明显改变。另外,讨论了膜厚引起FTO薄膜结构及光电性能变化的相关机制,分析了UV辐照对FTO薄膜光电性能的改善机理。     

溅射时间对GZO薄膜光电性能的影响

采用射频磁控溅射法在普通玻璃衬底上制备了Ga2O3含量为3wt.％的掺镓氧化锌透明导电薄膜(GZO).通过X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、四探针测试仪、台阶仪、UV-Vis-NIR3600型紫外-可见分光光度计研究了溅射时间对薄膜结构、表面形貌及光电性能的影响.结果表明,溅射时间为40 min时制备的GZO薄膜的光电综合性能最好,可见光区透过率峰值86％,方阻为16.4Ω/□,电阻率为1.18 ×10-3Ω·cm,性能指数ΦTc为4.73 ×10-3 Ω-1;随着溅射时间增加,薄膜光学带系从3.69 eV减少到3.56 eV.在溅射时间60 min时结晶度最高,方块电阻为9.0Ω/□,电阻率最低为9.7×10-4 Ω·cm,可见光透过率峰值为81％.     

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.