2-羟基-4-正辛氧基二苯甲酮的极谱行为

用线性扫描极谱法研究了在不同缓冲体系中2-羟基-4-正辛氧基二苯甲酮(简称BP-12)的极谱行为。实验表明,在2mol/L的H2SO4溶液中,BP-12的二阶导数峰电位为-0.92V,BP-12在两个浓度范围内与峰电流呈线性关系。在3×10-5~4×10-5mol/L的范围内,线性方程为ip″(nA/s2)=-2796.8 1.123×108c(mol/L),相关系数为0.9915;在1×10-6~9×10-6mol/L范围内,BP-12的浓度的对数值与电流成线性关系,线性方程为ip″(nA/s2)=669.60 94.69lgc(mol/L),相关系数为0.9972。BP-12的常规循环伏安曲线表明,该极谱波为不可逆还原波。初步讨论了电极反应机理。     

2-羟基-4-甲氧基二苯甲酮的极谱行为研究

用线性扫描极谱法研究了在B-R缓冲溶液中2-羟基-4-甲氧基二苯甲酮(又名BP-3)的极谱行为。实验表明,以pH=4.90的B-R缓冲溶液和0.1 mol/L KCl溶液作为底液,BP-3产生还原波,其二阶导数峰电位为-1.21 V(vs.SCE),峰电流与其浓度在9.46×10-7~4.73×10-5mol/L范围内呈线性关系,线性方程为ip”(μA/s2)=-0.039 96 3.307×105c,相关系数r=0.999 9。初步讨论了电极过程及电极反应机理,结果表明该波为不可逆吸附波。用标准加入法测定了合成试样及市售防晒护肤霜中BP-3的质量分数。     

2,2′,4,4′-四羟基二苯甲酮的极谱行为研究

用线性扫描极谱法系统研究了2,2′,4,4′-四羟基二苯甲酮(BP-2)在不同缓冲体系中的极谱行为.实验表明,在2.5 mol/L的H2SO4溶液中BP-2的二阶导数峰电位为-1.06 V,其峰电流与浓度在5.0×10-6mol/L～3.0×10-5mol/L的对数值有良好的线性关系,线性方程ip″(nA/s2)=19 096.79+745.75×lg c(mol/L),相关系数为0.993 6.BP-2的微分循环伏安曲线表明,该极谱波为不可逆还原波.     

2,2,＇4,4＇-四羟基二苯甲酮的极谱行为研究

用线性扫描极谱法系统研究了2,2,＇4,4＇-四羟基二苯甲酮（BP-2）在不同缓冲体系中的极谱行为。实验表明,在2.5 mol/L的H2SO4溶液中BP-2的二阶导数峰电位为-1.06 V,其峰电流与浓度在5.0×10^-6mol/L-3.0×10^-5mol/L的对数值有良好的线性关系,线性方程ip＂（nA/s^2）=19 096.79＋745.75×lgc（mol/L）,相关系数为0.993 6。BP-2的微分循环伏安曲线表明,该极谱波为不可逆还原波。     

甲基环糊精-对叔丁基酚包络物电化学研究及应用

本文主要研究了甲基-β-环糊精-对叔丁基酚包络物的极谱行为。在0.05mol/L的KCl底液中,甲基-?-环糊精-对叔丁基酚包络物在2.5次微分极谱仪上产生还原波,其峰电位为-0.85V(vs.SCE),其峰电位随对叔丁基酚浓度的增大而负移,峰形稳定;并且峰电流与对叔丁基酚浓度在1.0×10-5mol/L~6.0×10-5mol/L之间呈良好的线性关系,检测下限为1.0×10-5mol/L。     

过硫酸钾存在下的盐酸胺碘酮极谱催化波及其应用

基于K2S2O8存在下盐酸胺碘酮(ADHC)产生的极谱催化波,拟定了测定ADHC的新方法。在0.15mol/LKH2PO4Na2HPO4(pH5.6) 8.0×10-5mol/LK2S2O8底液中,ADHC于-1.32V(vs.SCE)产生的极谱催化波的二阶导数峰电流ip″与其浓度在8.0×10-8～4.0×10-7mol/L及4.0×10-7～8.0×10-5mol/L呈良好的线性关系,其线性回归方程分别为ip″/μA·s-2=-3.95 9.51×107cADHC(r=0.9939,n=7),ip″/μA·s-2=104.6 2.92×107cADHC(r=0.9958,n=7),检出限为2.70×10-8mol/L。该催化波的分析灵敏度比相应还原波提高了5倍左右,该方法用于测定ADHC的含量,结果满意。     

铜（Ⅱ）-孔雀石绿配合物极谱吸附波的研究

在0.5mol/L NH4C l溶液中,用单扫描示波极谱法在-0.69V（vs.SCE）可获得灵敏的铜-孔雀石绿（MG）配合物极谱吸附波,其二阶导数波峰高与孔雀石绿浓度在2.5×10-7-1.25×10-4mol/L范围内成正比关系,检出限为1.0×10-7mol/L,测得电活性配合物组成为Cu2＋：MG=1：4。该方法用于水样、土样中孔雀石绿的测定,回收率分别为95.2%-108.0%和92.0%-106.0%。     

维生素B1、维生素B2、维生素BC的极谱分析法

维生素B1、维生素B2、维生素BC混合物在pH为6.0的NaH2PO4-Na2HPO4缓冲溶液中均各自产生灵敏的极谱吸附波,且峰电位各不相同,依次为-1.5 V(vs.SCE)、-0.48 V(vs.SCE)、-0.90 V(vs.SCE)。且混合物浓度在1×10-4～6×10-2mol/L范围内维生素B1、维生素B2、维生素BC均与峰电流有良好的线性关系,线性系数分别为:0.9994、0.9960、0.9992,混合物的检出限为5×10-6mol/L。     

催化极谱法测定生物样品中的微量硒

建立了测定生物样品中微量硒的催化极谱法。试验发现Se(Ⅳ)与谷胱甘肽在-0.94 V(vs.SCE)处形成一个灵敏的极谱催化波。Se(Ⅳ)浓度在4.0×10-7~8.0×10-6mol/L的范围内,峰电流与Se(Ⅳ)浓度呈线性关系。Se(Ⅳ)的检出限为2.0×10-7mol/L,相对标准偏差均小于5%。此法简便、快速、灵敏,结果准确。     

铜(Ⅱ)-抗坏血酸-硫酸-硫氰酸钾极谱络合吸附波研究

用单扫描极谱法研究了Cu(Ⅱ)-H2SO4-硫氰酸钾体系的伏安行为,发现铜(Ⅱ)在抗坏血酸-H2SO4-硫氰酸钾试剂存在下,于-0.55 V(vs·SCE)左右产生一尖锐、灵敏的极谱波。经实验确定的最佳测定条件为:2.5 mol·L-1硫酸2m L,1%硫氰酸钾2 m L,10%抗坏血酸5 m L,铜(Ⅱ)的浓度在6.250×10-7~4.375×10-6mol·L-1范围内与相应的峰电流成线性关系好,回归方程为ip=348.98CCu(mol·L-1)-283.64,线性相关系数R为0.9993;最小检出浓度为4.0×10-7mol·L-1。方法用于人发中铜含量的测定,测定值与原子吸收光谱法测定值基本一致,相对标准偏差(n=6)为2.7%~4.1%,加标回收率96.2%~102.3%。     

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.