磺酰脲除草剂单嘧磺隆水解和水中光解研究

实验室条件下,利用高效液相色谱研究了单嘧磺隆水解和水中光解动态特性。结果表明,25℃时单嘧磺隆在pH 5、pH 7和pH 9缓冲溶液中的水解半衰期分别为42.5 d、248 d和19.7 h,50℃时则分别为32.8 h、117 h和12.5 h,水解速率随温度升高而升高,温度效应系数为1.58～50.9。单嘧磺隆在碱性缓冲溶液中水解最快,在中性条件下水解最慢,pH 9缓冲溶液的水解活化能和活化熵最小。在本研究试验条件下,单嘧磺隆在水中光解半衰期为45.3 h。     

碘甲磺隆钠盐在土壤和小麦中的残留动态

在长沙市马坡岭和北京市通县开展了碘甲磺隆钠盐在小麦植株和土壤中的残留降解动态试验.两地试验结果表明:在施药剂量为28.2 g a.i./hm2时,长沙市马坡岭试验点碘甲磺隆钠盐在小麦植株和土壤中的半衰期分别为4.1、7.4 d,北京市通县试验点碘甲磺隆钠盐在小麦植株和土壤中的半衰期分别为5.4、22 d,碘甲磺隆钠盐在小麦茎叶和土壤中都能迅速降解,其中在小麦植株中的降解更快.6.25%碘甲磺隆钠盐水分散粒剂用于小麦田除草,施药剂量分别为18.8、28.2 g a.i./hm2时,施药1次,收获期小麦籽粒、麦秆及土壤中的残留均低于0.003 mg/kg.     

苯醚甲环唑的水解研究

研究了苯醚甲环唑在水溶液中的水化学降解行为,结果表明:(1)苯醚甲环唑水解作用随溶液pH值的增大而增强,25℃时其在pH5、7和9的缓冲液中的水解半衰期分别为315.07、11.53和1.33d。(2)苯醚甲环唑在水体中的水解速率随温度升高而加快,其在温度为15、25、35、45℃的pH7缓冲液中的水解半衰期分别为20.81、11.53、6.80和2.14d,平均温度效应系数为2.22。苯醚甲环唑水解反应的平均活化能和活化焓分别为55.53kJ/mol和53.01kJ/mol,而苯醚甲环唑水解反应的活化熵随温度升高而降低,表现出明显的相关性,其平均活化熵为-92.45kJ/mol·k。(3)在相同的培养条件下,苯醚甲环唑在池塘水、河水和超纯水中的降解速率是不同的,其水解半衰期分别为7.31、4.47和12.49d。     

甲基碘磺隆钠盐在玉米和土壤中的残留分析及消解动态

[目的]研究甲基碘磺隆钠盐在玉米及土壤中的消解动态和残留变化趋势,评价甲基碘磺隆钠盐在玉米上使用的安全性。[方法]建立甲基碘磺隆钠盐在玉米和土壤中的残留检测方法,并测定其在玉米和土壤中的消解动态和最终残留。[结果]方法的准确度和精密度均符合残留检测要求,甲基碘磺隆钠盐在玉米植株中的消解半衰期为2.1~2.6 d;在土壤中的消解半衰期为4.7~6.5 d。按照剂量9.0~13.5 g a.i./hm2,施药1次,收获期玉米和土壤中的残留量均小于方法的最低检测质量分数(0.01 mg/kg)。[结论]建立的方法快速简单,准确可靠,玉米收获时甲基碘磺隆钠盐的残留量低于方法的最低检测质量分数。     

碘甲磺隆钠盐分析方法述评

总结了文献报道的碘甲磺隆钠盐的分析方法。碘甲磺隆钠盐的分析主要采用高效液相色谱法,可用于碘甲磺隆钠盐原药、制剂的分析。     

唑螨酯的水解特性

通过实验室的模拟试验研究了唑螨酯在不同温度、pH值及不同水体条件下的水解动态,以及表面活性剂这一水体常见影响因素对唑螨酯水解的影响.结果表明:在25℃和45℃条件下,pH值的变化对水解速率的影响不大,即水解速率大致相同在5℃时,水解速率随pH值变化有所不同,呈明显负相关.在3种pH值条件下,唑螨酯在水中的降解规律表现为随着温度的升高,水解速率加快,半衰期缩短.唑螨酯在缓冲溶液中的水解速率与在自然河水中的水解速率相似.随着表面活性剂浓度的增大,对于唑螨酯水解的影响越小.当SDBS质量浓度为10 mg/L时的影响最为显著,质最浓度为30、50 mg/L时对唑螨酯水解的影响不大,且两者影响程度相当.     

新颖水田除草剂——碘甲磺隆

碘甲磺隆系原安万特公司（现德国拜耳作物科学有限公司）开发的磺酰脲类谷物芽后除草剂。在应用中,其通常以甲酯、钠盐形式存在并发挥作用。1 理化性质 碘甲磺隆的通用铝为iodosulfuron,商品名Hussar,代号AEF115008,其甲酯、钠盐通用名为iodosulfuron-methylfodium.     

新型除草剂碘甲磺隆钠盐

碘甲磺隆钠盐属磺酰脲类除草剂,通过抑制乙酰乳酸合成酶而起作用,主要用于小麦田,苗后早期防除黑麦草、野燕麦、梯牧草和多种阔叶杂草。介绍了碘甲磺隆钠盐的合成方法。     

候选农药病氰硝水解和光解的特性

[方法]采用室内模拟方法研究了病氰硝在水环境中的动力学规律,考察病氰硝的光降解受pH值的影响以及水化学降解受pH值和温度的影响.[结果]在光解条件下的半衰期t1/2分别为5 h[pH值5,(25±1)℃]、1.6 h[pH值7,(25±1)℃]、1.4 h[pH值9,(25±1)℃]；该农药的水解半衰期t1/2分别为3.9 d[pH值7,(25±1)℃]、31.4 d[pH值9,(25±1)℃]、6.9 d[pH值7,(37±1)℃]、17.3 d[pH值9,(37±1)℃]、8.7 d[pH值7,(50±1)℃]、4.6 d[pH值9,(50±1)℃],在pH值5的缓冲溶液中较稳定.[结论]按《化学农药环境安全评价试验准则》规定,病氰硝属于易光解,在中性和碱性条件下易水解类农药.     

利用偶联反应光度法检测甲磺隆

在pH值为7．0的磷酸氢二钠-磷酸二氢钠体系中,甲磺隆与亚硝酸钠反应生成重氮盐,重氮盐与α-萘胺进行偶联反应生成红棕色化合物,该产物在500nm处有最大吸光值,据此,建立了利用偶联反应测定甲磺隆残留的新方法。在最佳条件下,甲磺隆质量浓度与吸光值呈良好的线形关系,线性范围为10～150mg／L。平均回收率为98．10％,相对标准偏差为2．12％。     

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。