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1.
几种化学药剂对菜蚜的活性研究   总被引:1,自引:0,他引:1  
测定了啶虫脒、莫比朗、吡虫啉和乐果对菜缢管蚜、桃蚜成虫的毒力,进行了室内药效试验和小区防效试验。结果表明:啶虫脒和莫比朗对桃蚜、采缢管蚜的LC50最低,乐果的LC50最高,吡虫啉介于前二者与后者之间;啶米和莫比朗的室内防桃蚜了,其次是吡虫啉;啶虫脒、莫比朗和吡虫啉室内防菜缢管蚜均大于90%,三者间无显著差异;啶虫脒、莫比朗和吡虫啉的田间防效结果差异不大,施药后7d的防效均大90%以上。  相似文献   

2.
十字花科蔬菜蚜虫田间种群对药剂的敏感性   总被引:1,自引:0,他引:1  
采用浸叶法,测定了昆明地区十字花科蔬菜3种蚜虫田间种群对8种杀虫剂的敏感性.结果表明,这3种蚜虫种群对苦参碱、除虫菊素、印楝素、啶虫脒、吡虫啉、氯氰菊酯、敌敌畏、乙酰甲胺磷的敏感性差异明显.其中,这3种蚜虫对乙酰甲胺磷高度不敏感,其对甘蓝蚜、萝卜蚜和桃蚜的LC50值分别为4868.68,2440.53和6379.34 mg/L;这3种蚜虫对敌敌畏也不敏感,其对甘蓝蚜、萝卜蚜和桃蚜的LC50值分别为259.76,95.24和567.59 mg/L;3种蚜虫对其它6种药剂的敏感性也存在差异,但相对较为敏感.  相似文献   

3.
反相高效液相色谱法测定附子有效成分含量的方法研究   总被引:7,自引:0,他引:7  
运用RP-HPLC测定不同地区附子药材中3种酯型生物碱———新乌头碱、乌头碱和次乌头碱的含量.实验以RP-C18色谱柱为固定相,乙腈-0.1%的乙二胺水溶液为流动相进行梯度洗脱.梯度洗脱程序:乙腈和0.1%的乙二胺水溶液的比率0~17 min为46∶54,17~37 min为82∶18;37~50 min为46∶54,流速为1.0mL/min;紫外检测波长为230 nm.新乌头碱、乌头碱和次乌头碱的标准曲线范围分别是5.62×10-6~5.062×10-5mol/L、2.614×10-6~2.614×10  相似文献   

4.
关于吡虫啉对玉米田蝗虫群落毒力的研究   总被引:1,自引:1,他引:0  
研究了吡虫啉对玉米田蝗虫杀伤毒力与群落结构的影响,结果表明玉米田有9种蝗虫,其中优势种为花胫纹蝗(Ajlopus thalasisinus tamulus(Fabr.)和黄胫小车蝗(Oedaleus infernalis Sauss),室内毒力试验,在田间使用浓度下,用药膜法和喷雾法测定了吡虫啉对两优秀种蝗虫的击倒作用,计算了KT50;以点滴法测得其他两优势种蝗虫的触杀作用LD50为39.5和27.3μg/头;浸叶法测得其胃毒作用LD50为35.0和14.1μg/L。田间试验喷药后10d防效均可在50%以上,同时喷药前后田间蝗虫群落结构也发生着明显的变化。  相似文献   

5.
通过以球孢白僵菌(Beauveria bassiana)菌株SGBB8601系列浓度的分生孢子悬液(10~4~10~8孢子/mL)对俄罗斯麦双尾蚜(Diuraphis noxia)、麦无网长管蚜(Metopolophium dirhodum)、麦长管蚜(Sitobion avenae)、麦二叉蚜(Schizaphis graminum)、玉米蚜(Rhopalosiphum maidis)、禾谷缢管蚜(R padi)和忽布疣额蚜(Phorodon humuli)等七种蚜虫的体表接种试验,运用时间-剂量-死亡率模型分析了该菌株作用于上述寄主的剂量、时间及其互作效应。所测菌株对所有蚜虫均具有毒力,接种后七日的LD_(50)为1.25×10~5~114.82×10~5孢子/mL,毒力因蚜种而异,双尾蚜和忽布疣额蚜最为敏感,玉米蚜与禾谷缢管蚜的敏感性相对较低,其余居间。这些结果表明所试菌株具有作为蚜虫微生物防治候选因子的潜势。本研究采用的分析方法较传统的Probit或Logit分析方法有显著的优越性,将时间和剂量效应的分析统一到一个模型中,使时间与剂量效应的互作评价成为可能。笔者介绍了该模型的生物学基础和建模步骤,并讨论了在生物学研究领域的应用前景。  相似文献   

6.
分别采用叶片浸叶法、喷雾法测定3种不同杀虫剂对葡萄斑叶蝉的毒力测定和田间药效。毒力测定表明:10%吡虫啉可湿性粉剂、25%阿克泰水分散粒剂和48%乐斯本乳油对葡萄斑叶蝉LC50分别是45.870、18.131、3.757μg·m L~(-1);田间试验表明:10%吡虫啉可湿性粉剂、25%阿克泰水分散粒剂和48%乐斯本乳油药后7 d防效均为100%,说明该3种药剂都具有很好的防效,且前两种杀虫剂药后持效期长,所以推荐10%吡虫啉可湿性粉剂、25%阿克泰水分散粒剂为防治葡萄斑叶蝉的最佳药剂。  相似文献   

7.
8种有机溶剂对肿瘤细胞的细胞毒作用   总被引:8,自引:0,他引:8  
实验中常需要有机溶剂溶解水溶性较差的待筛选样品,笔者为抗肿瘤药物体外筛选时选择适宜体积分数下低毒且溶解性能好的有机溶剂作参考.用改良MTT法测试8种常用溶剂对2种人肿瘤细胞株生长的影响.甲醇、乙酸乙酯、乙醇、乙二醇、二甲基亚砜(DMSO)、氯仿、丙酮和正丁醇对人肺癌细胞株A549的IC50分别为3.50,0.61,2.09×10-2,3.79×10-2,4.07×10-3,2.10×10-2,4.04×10-3,2.62×10-4?μg/mL;甲醇、乙酸乙酯、乙二醇、二甲基亚砜、氯仿、丙酮和正丁醇对人肝癌细胞株BeL-7402的IC50分别为0.28,0.89,5.82×10-2,9.67×10-3,5.54×10-2,8.00×10-3,1.61×10-3?μg/mL.结果说明体积分数为0~10%的甲醇和乙酸乙酯细胞毒性甚微,宜选用;乙醇、乙二醇选用低于3%的体积分数;DMSO宜用低于1%的体积分数;丙酮和氯仿宜选择低于0.3%的体积分数;正丁醇的细胞毒性较强,不适合用于筛药中.  相似文献   

8.
毛细管电泳电化学检测葛根和葛藤中几种黄酮类化合物   总被引:17,自引:0,他引:17  
用毛细管电泳电化学检测法测定了葛根和葛藤中葛根素、大豆甙元和芦丁含量.以碳圆盘电极为检测电极,电极电位为0.90V(vs.SCE),在50mmol/L硼酸盐缓冲液(pH9.0)中,使用长40cm熔融石英毛细管,当分离电压为9kV,上述三组分在12min内完全分离.葛根素、大豆甙元和芦丁浓度与电泳峰电流分别在2.5×10-6~1.0×10-3,1.0×10-6~1.0×10-3和5.0×10-6~1.0×10-3mol/L范围内呈良好线性,检出限(S/N=3)分别为3.4×10-7,2.4×10-7和5.1×10-7mol/L.7次测定葛根素、大豆甙元和芦丁的混合标准溶液,峰高的相对标准偏差分别为2.71%,2.47%和4.21%.  相似文献   

9.
室内测定了苦豆子7种生物碱对椰心叶甲3龄幼虫的拒食及毒杀作用,结果表明:苦豆子7种生物碱对椰心叶甲3龄幼虫均具有明显的拒食作用,其中以苦豆碱的活性最高,处理后24 h和48 h的拒食率分别为90.35%和93.27%(1 mg/mL)。毒杀试验显示野靛碱和苦豆碱的毒杀作用要优于其他生物碱,处理后第9天的校正死亡率均达到100%。此外,苦豆子7种生物碱对椰心叶甲还有一定的杀卵作用,野靛碱和苦豆碱在处理后第5天的卵孵化率均小于12%(2 mg/mL)。  相似文献   

10.
基于盐酸小檗碱抑制磷钼钒杂多酸氧化鲁米诺产生化学发光,结合流动注射分析技术,提出了一种测定盐酸小檗碱的新方法.盐酸小檗碱在1.0×10-7~1.0×10-4 g/mL浓度范围内与化学发光分析信号呈线性关系;检出限为4×10-8 g/mL;对5.0×10-6 g/mL的盐酸小檗碱进行11次连续测定,相对标准偏差为1.2%.该方法已成功地应用于盐酸黄连素片剂中盐酸小檗碱的测定.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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