共查询到19条相似文献,搜索用时 218 毫秒
1.
运用浸渍法和叶片残毒法测定了4种杀螨剂及其混剂对二斑叶螨抗性种群不同发育阶段的致毒作用。结果表明:阿维菌素对雌成螨的毒力最高,LC50为0.0864mg/L;其次为溴虫腈和阿维菌素+哒螨灵(1:15),LC50分别为9.5377mg/L和1.4412mg/L。对卵的毒力溴虫腈最高,LC50为0.1223mg/L;其次为阿维菌素和阿维菌素+哒螨灵(1:15),LC50分别为0.4425mg/L和0.6827mg/L。对二斑叶螨的室内控制效果依次为溴虫腈>阿维菌素+哒螨灵(1:15)>哒螨灵>阿维菌素>哒螨灵+甲氰菊酯(1:1)>甲氰菊酯。 相似文献
2.
3.
不同地理种群甘薯茎线虫对不同类型杀线剂的敏感性 总被引:3,自引:0,他引:3
采用浸渍法和沙柱法测定了河北省昌黎、涿州、卢龙和抚宁四地的甘薯茎线虫对涕灭威、灭线磷、阿维菌素的敏感性。浸渍法结果表明,昌黎甘薯茎线虫种群对涕灭威、灭线磷的LC50分别为891.73、743.82mg/L,其它三地涿州、卢龙和抚宁甘薯茎线虫种群对涕灭威、灭线磷的敏感性均有所降低,与昌黎种群相比较,其对涕灭威的抗性倍数分别为4.0、3.5和3.7倍,对灭线磷的抗性倍数分别为3.8、2.1和1.6倍;阿维菌素在400mg/L以下时,各种群的死亡率均在45%以下,为600mg/L时其死亡率陡增,均为90%以上,且无显著性差异。沙柱法结果表明,5mg/L的涕灭威和50mg/L的灭线磷对线虫的活动能力具有很好的抑制作用,50mg/L的阿维菌素抑制作用则相对较低。 相似文献
4.
5.
本文报导了高效液相色谱法定量分析2,6-二硝基氯苯-4-磺酸的方法。采用Diamonsil C18色谱枉,甲醇/水为流动相(60/40)(每500ml流动相中舍有0.30g磷酸二氢钾),检测波长为215nm,线性范围19.83mg/L~99.16nm/L,r=0.9999;标准偏差为0.16,回收率为99.50%~100.10%。 相似文献
6.
甲氨基阿维菌素苯甲酸盐对4种非靶生物毒性及安全性评价 总被引:12,自引:3,他引:9
测定了甲氨基阿维菌素苯甲酸盐对4种有代表性的非靶生物蜜蜂、鹌鹑、斑马鱼、家蚕的急性毒性,并进行了安全性评价。试验结果表明,甲氨基阿维菌素苯甲酸盐对蜜蜂触杀LD50(48h)为0.009064μg/蜂,胃毒LC50(48h)为1.024mg/L,对雌、雄鹌鹑LC50(7d)为35.92、38.53mg/kg,对斑马鱼LC50(96h)为0.2390mg/L,对家蚕LD50(96h)为0.01109mg/kg桑叶。该农药对蜜蜂、鹌鹑、斑马鱼毒性均为高毒级,对家蚕毒性为特高毒级。此项工作为甲氨基阿维菌素苯甲酸盐的合理使用提供了科学依据。 相似文献
7.
苦参生物碱杀虫生物活性测定 总被引:30,自引:2,他引:30
以桃蚜等9种试虫为供试靶标,研究了苦参根提取物和苦参碱、氧化苦参碱、槐果碱、野靛碱的杀虫活性。试验结果表明:苦参生物碱具有一定的杀虫活性,9种试虫中,苦参根提取物对蚜虫的活性最高,其对蚕豆蚜的LC50为20.635mg/L;即使在最高剂量为4000mg/L时,也不能直接杀死粘虫、小菜蛾和棉铃虫。4种生物碱对朱砂叶螨活性均较低,LC50均大于2500mg/L。野靛碱是4种生物碱中杀虫活性最高的,对淡色库蚊、桃蚜、蚕豆蚜、褐飞虱和家蝇的LC50分别为172.431mg/L、207.667mg/L、85.212mg/L、266.179mg/L和763.224mg/L;而且对褐飞虱、桃蚜和家蝇的活性高于苦参根提取物,苦参碱对蚜虫的活性高于氧化苦参碱和槐果碱,槐果碱对淡色库蚊、褐飞虱和家蝇的活性高于苦参碱和氧化苦参碱。 相似文献
8.
五种杀虫剂对小菜蛾的室内生物活性研究 总被引:10,自引:0,他引:10
小菜蛾Plutella xylostella是十字花科蔬菜的主要害虫,其造成的为害给蔬菜生产带来巨大损失。本文采用触杀毒力法和摄食毒力法测定了5种新颖的杀虫剂对小菜蛾的室内生物活性,研究结果表明:采用浸渍法处理72h,10%溴虫腈乳油和5.44%丁烯氟虫腈乳油对小菜蛾的触杀活性较好,其LC50值分别为1.758mg/L和2.289mg/L;采用药膜法处理72h,5.44%丁烯氟虫腈乳油和5%锐劲特悬浮剂对小菜蛾表现出了优越的胃毒作用活性,其LC50值分别为0.165mg/L和0.259mg/L。 相似文献
9.
应用高效液相色谱法,采用LichrospherRP-8柱,0.075moL/L kh2PO4-乙腈-甲醇1:1:1为流动相,254nm检测,建立了测定利福平胶囊含量的方法,在4-120mg/L范围内,峰面积比与浓度呈良好的线性关系,r=0.9998。样品加样回收率为100.1%,RSD为0.77%。方法较美国药典HPLC法简便、快速,较中国药典方法灵敏、重现性好。 相似文献
10.
11.
12.
13.
采用高分子网络凝胶法制备了ZnO粉末样品。通过X射线衍射、扫描电镜等测试方法研究了样品的物相组成、微观形貌。X射线衍射测试结果显示,样品的衍射峰尖锐,各特征峰显示完整,与标准PDF卡片比对,证实粉末样品的物相为ZnO。使用Scherrer公式计算得到的晶粒度大小约为31.28nm,晶格常数分别为3.247和5.208。使用扫描电镜观测不同放大倍数下的样品形貌,发现晶粒外观形貌显现完整,晶粒尺寸大小与XRD测试结果相吻合。结果表明,实验成功制备了高质量的ZnO纳米多晶粉体,可以用于后续实验。 相似文献
14.
15.
孔隙压力传递是泥页岩井壁失稳的重要机理之一,纳微米尺度氧化石墨烯的研究为泥页岩孔隙封堵提供了新的途径。针对四川龙马溪组泥页岩,基于扫描电镜(SEM)、氮气吸附等方法表征了其孔隙结构;以改性Hummers法制备了厚度约为1.2 nm,平均片层尺寸分布范围为197 nm - 969.9 nm的氧化石墨烯(GO),并通过压力传递实验评价了其封堵性能;基于封堵后泥页岩的 SEM 及 X 射线能量色散谱(EDS)测试,探讨了GO封堵泥页岩岩心的主要机理。结果表明,片层尺寸为969.9 nm、质量分数为0.1%的GO阻缓压力传递效果最明显,其1 MPa压差传递时间为1000 s,而蒸馏水传递时间为30 s;GO呈半透明絮状膜堆叠、覆盖在岩心表面,对岩心纳微米孔隙进行了充填与封堵。 相似文献
16.
Samples of a high-volatile bituminous coal (HVab) were examined by means of transmis sion electron microscopy in a high-voltage electron microscope (1 MeV). The porosity observed within the exinite and inertinite constituents of this coal falls primarily into the mesopore size range (2–50 nm). Small particles (≈25 nm in diameter) were seen in a majority of the exinite pores and are believed to have acted as catalysts in the pore formation. 相似文献
17.
FilipeLS Mello LídiaOO Costa EduardoPadrón Hernández AndréaMDuarte de Farias Marco A Fraga 《Nanoscale research letters》2010,5(6):1002-1009
The present contribution reports on the features of platinum-based systems supported on vanadium oxide nanotubes. The synthesis
of nanotubes was carried out using a commercial vanadium pentoxide via hydrothermal route. The nanostructured hybrid materials
were prepared by wet impregnation using two different platinum precursors. The formation of platinum nanoparticles was evaluated
by applying distinct reduction procedures. All nanostructured samples were essentially analysed by X-ray diffraction and transmission
electron microscopy. After reduction, transmission electron microscopy also made it possible to estimate particle size distribution
and mean diameter calculations. It could be seen that all reduction procedures did not affect the nanostructure of the supports
and that the formation of metallic nanoparticles is quite efficient with an indistinct distribution along the nanotubes. Nevertheless,
the reduction procedure determined the diameter, dispersion and shape of the metallic particles. It could be concluded that
the use of H2PtCl6 is more suitable and that the use of hydrogen as reducing agent leads to a nanomaterial with unagglomerated round-shaped
metallic particles with mean size of 6–7 nm. 相似文献
18.
A pentadentate salen-type ligand was immobilized in a poly[(styrene)]-co-(butyl acrylate)] matrix by miniemulsion polymerization. The obtained polymer beads revealed a particle size of 50 nm in the dry state by transmission electron microscopy. Dynamic light scattering experiments in methanol and water showed a solvent-dependent average particle size with a mean particle diameter of up to 233 nm in methanol. These results provide valuable insights for the optimization of macromolecular oxidation catalysts and their future use as enzyme-like entities in aqueous media. The particle stability was demonstrated over a wide pH range (3-11) by gel permeation chromatography, and initial results for the metal ion binding ability were obtained. 相似文献
19.
K. Ko
í L. Obalov L. Matjov D. Plach Z. Lacný J. Jirkovský O. olcov 《Applied catalysis. B, Environmental》2009,89(3-4):494-502
Pure TiO2 anatase particles with a crystallite diameters ranging from 4.5 to 29 nm were prepared by precipitation and sol–gel method, characterized by X-ray diffraction (XRD), BET surface area measurement, UV–vis and scanning electron microscopy (SEM) and tested in CO2 photocatalytic reduction. Methane and methanol were the main reduction products. The optimum particle size corresponding to the highest yields of both products was 14 nm. The observed optimum particle size is a result of competing effects of specific surface area, charge–carrier dynamics and light absorption efficiency. 相似文献