福美双的测定方法测定

根据福美双能与Ｃｕ＾２＋形成黄色络合物的性质，提出了用分光光度法测定福美双原药含量的方法。测定波长为４３０ｎｍ。本法具有简便，快速的优点。     

福美双的分光光度测定法

根据福美双能与Ｃｕ＾２＋形成黄色络合物的性质，提出用分光光度法测定福美双原药含量的方法，测定波长为４３０米。本法具有简便、快速的优点。     

高效液相色谱法测定40%硫磺·三唑酮·福美双可湿性粉剂

采用正相高效液相色谱法同时测定硫磺、三唑酮、福美双。该方法具有样品准备简单 ,共存组分互不干扰测定 ,分析速度快等优点 ,可以用于硫磺·三唑酮·福美双可湿性粉剂中有效成分的快速测定     

高效液相色谱法同时测定克百威、福美双和萎锈灵

目的:建立高效液相色谱法同时测定克百威、福美双和萎锈灵的含量。方法:试样用甲醇溶解,采用等度洗脱的方法,以甲醇-乙腈-水为流动相,同时对萎锈灵、克百威和福美双进行分离,外标法定量。结果:测定克百威的方法线性相关系数为0.9997,变异系数为1.34%,平均回收率为100.7%;测定福美双的方法线性相关系数为0.9998,变异系数为1.50%,平均回收率为99.4%;测定萎锈灵的方法线性相关系数为0.9998,变异系数为1.42%,平均回收率为101.2%。结论:方法满足农药产品含量分析的要求,可同时测定克百威、福美双和萎锈灵的含量。     

比色法快速测定小麦中福美双的残留量

[目的]福美双是一种有机硫类保护性广谱杀菌剂,其测定方法主要有极谱法、高效液相色谱法、ELLSA法、紫外分光光度法等,这些方法操作步骤繁琐、分析速度慢、测试成本高,不适合基层检测单位使用。建立了一种快速测定小麦中福美双残留量的比色方法。[方法]首先用三氯甲烷提取样品中残留的福美双,然后用固体碘化亚铜处理,使Cu2+与福美双形成黄色的且溶于三氯甲烷的配合物二甲基二硫代氨基甲酸铜,于440 nm处进行测定,根据工作直线求得小麦中福美双的残留量。[结果]该方法的福美双标准溶液质量浓度在0.3~20 mg/L范围内呈良好线性关系,加标回收率在90%~110%之间,方法检测限为0.15 mg/kg,检测时间可控制在2 h以内。[结论]建立了一种快速测定小麦中福美双残留量的方法,该方法操作简便,测试速度快,成本低,便于基层单位监控、市场准入前的筛选或生产单位自控。     

HPLC法测定种衣剂中多菌灵、福美双含量

采用高效液相色谱法(HPLC法)测定种衣剂中多菌灵、福美双含量。实验结果表明,该方法测定的多菌灵、福美双在一定的质量浓度范围内呈良好线性关系,平均回收率分别为98.3%、97.1%,相对标准偏差分别为0.625%、0.995%。该方法简便、准确可行、灵敏度高。     

薄层—紫外法测定水稻种衣剂中多菌灵和福美双含量

近年来,多菌灵、福美双应用较为广泛,由这两个组分配制成的种衣剂,毒性小,杀菌谱广,既能防病治病,又能保证种子的出苗率。目前多菌灵单剂含量的测定采用非水电位滴定和薄层紫外法,而福美双含量多采用黄原酸盐法。本文就薄层－紫外比色法对该种衣剂中多菌灵和福美双...     

福美双与啶菌恶唑复配对灰葡萄孢活性的协同抑制作用

为了明确福美双与啶菌恶唑复配对灰葡萄孢Botrytis cinerea的协同抑制作用，首先采用菌丝生长速率法对保定与承德不同地区的灰霉菌株进行复配试验，筛选出福美双与啶菌恶唑的最佳增效组合5：1。同时测定了福美双与啶菌恶唑的最佳增效组合5：1对孢子和菌核的抑制活性以及对菌丝内容物含量的影响。结果显示，其5：1组合与对照、单剂进行比较，其5：1组合对孢子萌发、菌核的产生和萌发和可溶性糖、可溶性蛋白含量具有显著抑制作用。利用离体叶片法对灰葡萄孢活性进行检测，5：1组合处理在病斑直径、发病率、产孢量和孢子萌发率方面较对照、单剂差异显著，其抑制作用最大。综上所述，福美双与啶菌恶唑复配对灰葡萄孢活性具有协同增效抑制作用。     

液相色谱法测定40%甲福可湿性粉剂有效成分

采用高效液相色谱法，以甲醇－乙腈－水为流动相，采用ｓｐｈｅｉｓｏｂ Ｃ１８色谱柱，成功地测定了４０％甲福可湿性粉剂中甲基硫菌灵和福美双的含量。     

植物生长调节剂与杀菌剂互作对棉花立枯病的影响

采用温室盆栽方法，测定了5种植物生长调节剂分别与7种杀菌剂混用拌种对棉苗立枯病的影响，结果表明：水杨酸 三唑酮、水杨酸 甲基立枯磷、萘乙酸 三唑酮、萘乙酸 烯唑醇、氯化胆碱 甲基立枯磷、氯化胆碱 烯唑醇、油菜素内酯 三唑酮、油菜素内酯 丙环唑、油菜素内酯 多菌灵、多效唑 福美双对棉苗立枯病均有增效作用；水杨酸 福美双有拮抗作用；其它植物生长调节剂与杀菌剂互作为相加作用。     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.