表面活性剂对甘蓝叶子润湿性能试验

研究了十二烷基硫酸钠（SDS），十二烷基苯磺酸钠（LAS），烷基酚聚氧乙烯醚（OP－10），异辛醇聚氧乙烯醚（JFC）以及LAS与OP复配体系对甘蓝叶子的润湿性能。结果表明：单一表面活性剂OP润湿性能较好，LAS与OP复配体系的润湿性能与OP相近。     

樟树和黄花蒿浸提物对菜粉蝶幼虫的生物活性

研究了樟树和黄花蒿的乙醇、氯仿、石油醚浸提物对菜粉蝶幼虫的拒食作用、触杀作用。结果表明黄花蒿乙醇浸提物和樟树石油醚浸提物的活性较好,48 h拒食率分别为72.11%、57.86%;干物质触杀作用的LC50分别为1.232 g/L、1.275 g/L。     

溴氟菊酯防治大豆食心虫,大豆蚜,甘蓝夜蛾试验

１９９２～１９９５年用１０％溴氟菊酯乳油对大豆食心虫、大豆蚜、甘蓝夜蛾进行了小区试验。结果表明，该药对上述三种害虫具有良好的防效。ｌ０００倍液对大豆食心虫防治效果与２０％甲氰菊酯乳油２０００倍液相当，达到３９２．９％以上；用１０００～２０００倍液防治大豆蚜，药后７天防效达８８．５％以上；用５００～１５００倍液防治甘蓝夜蛾，药后７天均达到了８４．６％以上的防治效果。而且对作物安全。     

Behavioral and physiological responses of cabbage looper,Trichoplusia ni (Hübner), to steam distillates from resistant versus susceptible soybean plants

Soybean plant volatiles, extracted as steam distillates, significantly affected the behavior and biology of the cabbage looper,Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae). Distillates from the susceptible Davis variety attractedT. ni larvae and female adults, whereas those from resistant PI 227687 plants repelled them. When mixed in an artificial diet, steam distillates from PI 227687 plants caused mortality of first-instar larvae. Adults emerging from pupae topically treated with 5 g of such PI 227687 extractable showed developmental abnormalities. Larval feeding was significantly less on Davis leaves treated with PI 227687 volatiles as compared to solvent (acetone) or such Davis extractables. However, Davis volatiles on PI 227687 leaves did not increase larval feeding. HPLC analyses of steam distillates from susceptible Davis versus resistant PI 227687 indicated differences.     

A Flavanone and Two Phenolic Acids from Chrysanthemum morifolium with Phytotoxic and Insect Growth Regulating Activity

Leaves of Chrysanthemum morifolium cv. Ramat were extracted sequentially with hexane, ethyl acetate, and methanol. The methanol fraction, when incorporated into artificial diet was found to reduce the growth of cabbage looper (Trichoplusia ni Hubner) larvae at concentrations between 500 and 5000 ppm of diet. Fractionation of the methanol extract on a Sephadex column yielded five fractions, three of which reduced the weight of larvae relative to the control. One fraction was analyzed using high performance liquid chromatography (HPLC) and found to contain three main constituents. These compounds were purified using a combination of gel permeation chromatography on Sephadex LH20 and HPLC, and analyzed by 1H and 13CNMR as well as undergoing chemical and physical analyses. The compounds were identified as: 1, chlorogenic acid (5-O-caffeoylquinic acid); 2, 3,5-O-dicaffeoylquinic acid; and 3, 3', 4',5-trihydroxyflavanone7-O-glucuronide (eriodictyol7-O-glucuronide). At concentrations between 100 to 1000 ppm these compounds reduced both growth and photosynthesis of Lemna gibba L. with the order of efficacy being: flavanone > chlorogenic acid > 3,5-O-dicaffeoylquinic acid. Furthermore, when incorporated separately into artificial diet these compounds, at 10 to 1000 ppm, enhanced or reduced growth of the cabbage looper (Trichoplusia ni) and gypsy moth (Lymantria dispar L.).     

Chemical constituents of an unacceptable crucifer,Erysimum cheiranthoides,deter feeding byPieris rapae

The wild cruciferErysimum cheiranthoides was found to contain extractable constituents that deterred feeding by larvae of the crucifer specialistPieris rapae when applied to cabbage leaf disks in both choice and nochoice bioassays. High-performance liquid chromatography was used to separate the extract into several fractions, two of which retained the feeding deterrent activity of the extract. UV-absorption spectra of the fractions suggested that one contained cardenolides similar or identical to those reported to deter oviposition byP. rapae onE. cheiranthoides. The other active fraction evidently contains a compound that deters larval feeding but not adult oviposition. The results suggest that the chemical defense ofE. cheiranthoides depends on two types of compounds acting on separate developmental stages of the insect.     

超声波辅助提取紫甘蓝色素的工艺研究

研究了紫甘蓝色素的提取工艺．以市售紫甘蓝为原料,以超声波辅助提取紫甘蓝色素,考察提取溶剂、液固比、温度、超声波功率、提取时间以及pH等因素对提取效果的影响．通过实验可知：紫甘蓝色素的最佳提取剂为蒸馏水,以超声波辅助提取可明显提高提取率．在以蒸馏水为提取剂的条件下,紫甘蓝色素的最大吸收波长为560nm．以超声波辅助提取时,最适液固比为5：1（mL／g）,提取最适温度为50℃,超声波最适功率为70W,最适提取时间为20min．pH对紫甘蓝色素的影响较大,紫甘蓝色素在不同pH下颜色发生明显变化．     

甲基对硫磷在小白菜上的降解动态及最终残留量

为了解甲基对硫磷在小白菜上的降解动态及最终残留量，指导该农药的使用，给安全食用小白菜提供科学依据，该试验在银川郊区银新乡农户的温室菜棚中进行。喷药后第零天，第一天，第二天，第三天，第五天，第七天，每天分别取样，用气相色谱法分析测定甲基对硫磷在小白菜上的残留量，得出甲基对硫磷残留量(Y)与时间(t)的关系。实验结果表明，甲基对硫磷在小白菜上半衰期为2．91天；喷药后第七天，在小白菜中未检出甲基对硫磷的残留。     

QuEChERS-气相色谱-串联质谱法测定结球甘蓝中甲基毒死蜱农药残留不确定度评估

目的对QuEChERS-气相色谱-串联质谱法测定结球甘蓝中甲基毒死蜱农药残留进行不确定度评估。方法运用气相色谱-串联质谱法对结球甘蓝中甲基毒死蜱残留量进行测定,通过建立数学模型,分析测定过程的主要不确定度来源,对各个分量进行评估。结果不确定性的主要来源是标准溶液的配制、工作曲线的拟合及加标回收率引入。当甲基毒死蜱的残留量为0.041 mg/kg时,扩展不确定度为0.003 mg/kg (k=2)。结论该方法适用于气相色谱-串联质谱法测定甲基毒死蜱残留量的不确定度分析,可为农药残留测量结果的准确性提供科学可靠的依据。