以苹果黄蚜AphiscitricolavanderGoot为试虫,对金合欢醇和烟碱的联合杀蚜活性进行了测定,以期为开发植物源杀蚜剂产品奠定基础。室内毒力测定采用微量点滴法;田间药效试验参照国家标准进行。金合欢醇和烟碱混用具有明显的杀蚜增效作用,...以苹果黄蚜AphiscitricolavanderGoot为试虫,对金合欢醇和烟碱的联合杀蚜活性进行了测定,以期为开发植物源杀蚜剂产品奠定基础。室内毒力测定采用微量点滴法;田间药效试验参照国家标准进行。金合欢醇和烟碱混用具有明显的杀蚜增效作用,在最佳质量配比(金合欢醇:烟碱=4.82:1)下,共毒系数(CTC)达151.63;经过对溶剂、表面活性剂等助剂的筛选,研制出6%烟碱·金合欢醇可溶液剂,配方为金合欢醇(5%)、烟碱(1%)、表面活性剂(10%)、溶剂(84%),质量检测符合可溶液剂国家质量标准;田间药效试验表明,以126.0 g a.i./hm^2常量喷雾,药后7 d对小麦上的麦长管蚜Sitobion avenae Fabricius和麦二叉蚜Schizaphis graminum(Rondani)混合种群的防效达87.80%,以115.5 g a.i./hm^2常量喷雾,药后7d对苹果黄蚜的防效在81%以上。可见,金合欢醇和烟碱复配具有显著的杀蚜增效作用,具有进一步开发潜力。展开更多
目的:研究大米草黄酮(Spartina anglica flavone,SAF)的体外抗菌效果及机理。方法:以铜绿假单胞菌等5种常见临床病原菌为试验菌株,采用牛津杯法测量抑菌圈并观察SAF的药物敏感性;采用微量稀释法测定SAF的最小抑菌浓度(MIC)及最小杀菌浓...目的:研究大米草黄酮(Spartina anglica flavone,SAF)的体外抗菌效果及机理。方法:以铜绿假单胞菌等5种常见临床病原菌为试验菌株,采用牛津杯法测量抑菌圈并观察SAF的药物敏感性;采用微量稀释法测定SAF的最小抑菌浓度(MIC)及最小杀菌浓度(MBC);测量经5 g/L SAF处理后的铜绿假单胞菌菌液中的磷含量,并通过SDS-PAGE分析铜绿假单胞菌蛋白质的表达情况,初步探讨了SAF的抑菌机理。结果:SAF对铜绿假单胞菌具有一定的抑制作用,对其余4种细菌无明显抑制作用;经SAF处理后,细菌对磷的消耗量降低,通过SDS-PAGE分析,证实SAF可能影响铜绿假单胞菌蛋白质的正常表达。结论:SAF对铜绿假单胞菌有一定的抗菌活性,其抑菌机制可能与SAF对细菌细胞膜的破坏力相关。展开更多
This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mechanisms and from ...This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mechanisms and from different sources in nature. It is demonstrated that the biodegradation or thermodegradation of complex high-molecule sedimentary organic material can form microbial gas or thermogenic gas. The δ13C1 value ranges from ?110% to ?50% for microbial gases but from ?50% to ?35% (even heavier) for thermogenic gases. Controlled by the kinetic isotope fractionation, both microbial and thermogenic gases have δ13C and δ D values characterized by normal distribution, i.e. δ13C1< δ 13C2< δ 13C3< δ 13C4 and $ \delta D_{CH_4 } < \delta D_{C_2 H_6 } < \delta D_{C_3 H_8 } < \delta D_{C_4 H_{10} } $ , and by a positive correlation between the δ 13C and δ D values. Simple carbon-bearing molecules (CH4, CO and CO2) can form abiogenic alkane gases via polymerization in the abiological chemical process in nature, with δ13C1 heavier than ?30‰ Moreover, controlled by the kinetic isotope fractionation, abiogenic alkane gases are characterized by a reverse distribution of δ 13C values and a normal trend of δ D values, namely δ13C1> δ 13C2> δ 13C3> δ 13C4 and $ \delta D_{CH_4 } < \delta D_{C_2 H_6 } < \delta D_{C_3 H_8 } < \delta D_{C_4 H_{10} } $ . The δ 13C values and δ D values are negatively correlated. Natural gases from 26 commercial gas wells distributed in the Xujiaweizi and Yingshan-Miaotaizi faulted depressions in the Songliao Basin, China, show δ13C1 values ranging from ?30.5% to ?16.7% with a very narrow δ D range between ?203‰?196‰ These gases are characterized by a reverse distribution of δ 13C values but a normal distribution of δ C values, and a negative correlation between their δ 13C and δ C values, indicating an abiological origin. The present study has revealed that abiogenic hydrocarbons not only exist in nature but also can make significant contribution to commercial gas reserviors. It is estimated that the reserve volume of alkane gases with abiogenic characteristics in these 26 gas wells in the Songliao Basin is over 500×108 m3. The prospecting practice in the Songliao Basin has demonstrated that abiogenic alkane gases are of a promising resource, and it provides an example for the investigation of and search for abiogenic commercial natural gases worldwide.展开更多
This book is a diary-style firsthand record written by Teacher Li Zhenxi,capturing in detail the raw educational events and authentic feelings he experienced during his time at school,and truly reconstructing the dail...This book is a diary-style firsthand record written by Teacher Li Zhenxi,capturing in detail the raw educational events and authentic feelings he experienced during his time at school,and truly reconstructing the daily growth of both Teacher Li and the children.The content is vivid and engaging,with strong readability and compelling impact,presenting over one hundred“class leadership crosssections”from the perspective of a frontline class head,making it a riveting“class leadershipepic”.展开更多
文摘以苹果黄蚜AphiscitricolavanderGoot为试虫,对金合欢醇和烟碱的联合杀蚜活性进行了测定,以期为开发植物源杀蚜剂产品奠定基础。室内毒力测定采用微量点滴法;田间药效试验参照国家标准进行。金合欢醇和烟碱混用具有明显的杀蚜增效作用,在最佳质量配比(金合欢醇:烟碱=4.82:1)下,共毒系数(CTC)达151.63;经过对溶剂、表面活性剂等助剂的筛选,研制出6%烟碱·金合欢醇可溶液剂,配方为金合欢醇(5%)、烟碱(1%)、表面活性剂(10%)、溶剂(84%),质量检测符合可溶液剂国家质量标准;田间药效试验表明,以126.0 g a.i./hm^2常量喷雾,药后7 d对小麦上的麦长管蚜Sitobion avenae Fabricius和麦二叉蚜Schizaphis graminum(Rondani)混合种群的防效达87.80%,以115.5 g a.i./hm^2常量喷雾,药后7d对苹果黄蚜的防效在81%以上。可见,金合欢醇和烟碱复配具有显著的杀蚜增效作用,具有进一步开发潜力。
文摘目的:研究大米草黄酮(Spartina anglica flavone,SAF)的体外抗菌效果及机理。方法:以铜绿假单胞菌等5种常见临床病原菌为试验菌株,采用牛津杯法测量抑菌圈并观察SAF的药物敏感性;采用微量稀释法测定SAF的最小抑菌浓度(MIC)及最小杀菌浓度(MBC);测量经5 g/L SAF处理后的铜绿假单胞菌菌液中的磷含量,并通过SDS-PAGE分析铜绿假单胞菌蛋白质的表达情况,初步探讨了SAF的抑菌机理。结果:SAF对铜绿假单胞菌具有一定的抑制作用,对其余4种细菌无明显抑制作用;经SAF处理后,细菌对磷的消耗量降低,通过SDS-PAGE分析,证实SAF可能影响铜绿假单胞菌蛋白质的正常表达。结论:SAF对铜绿假单胞菌有一定的抗菌活性,其抑菌机制可能与SAF对细菌细胞膜的破坏力相关。
基金Supported by National Natural Science Foundation of China (Grant Nos. 49233060, 40572087)Key Technologies R & D Programme (Grant Nos.96110010602, 2008ZX05008)the Foundation of Chinese Academy of Sciences (Grant No. K2000315)
文摘This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mechanisms and from different sources in nature. It is demonstrated that the biodegradation or thermodegradation of complex high-molecule sedimentary organic material can form microbial gas or thermogenic gas. The δ13C1 value ranges from ?110% to ?50% for microbial gases but from ?50% to ?35% (even heavier) for thermogenic gases. Controlled by the kinetic isotope fractionation, both microbial and thermogenic gases have δ13C and δ D values characterized by normal distribution, i.e. δ13C1< δ 13C2< δ 13C3< δ 13C4 and $ \delta D_{CH_4 } < \delta D_{C_2 H_6 } < \delta D_{C_3 H_8 } < \delta D_{C_4 H_{10} } $ , and by a positive correlation between the δ 13C and δ D values. Simple carbon-bearing molecules (CH4, CO and CO2) can form abiogenic alkane gases via polymerization in the abiological chemical process in nature, with δ13C1 heavier than ?30‰ Moreover, controlled by the kinetic isotope fractionation, abiogenic alkane gases are characterized by a reverse distribution of δ 13C values and a normal trend of δ D values, namely δ13C1> δ 13C2> δ 13C3> δ 13C4 and $ \delta D_{CH_4 } < \delta D_{C_2 H_6 } < \delta D_{C_3 H_8 } < \delta D_{C_4 H_{10} } $ . The δ 13C values and δ D values are negatively correlated. Natural gases from 26 commercial gas wells distributed in the Xujiaweizi and Yingshan-Miaotaizi faulted depressions in the Songliao Basin, China, show δ13C1 values ranging from ?30.5% to ?16.7% with a very narrow δ D range between ?203‰?196‰ These gases are characterized by a reverse distribution of δ 13C values but a normal distribution of δ C values, and a negative correlation between their δ 13C and δ C values, indicating an abiological origin. The present study has revealed that abiogenic hydrocarbons not only exist in nature but also can make significant contribution to commercial gas reserviors. It is estimated that the reserve volume of alkane gases with abiogenic characteristics in these 26 gas wells in the Songliao Basin is over 500×108 m3. The prospecting practice in the Songliao Basin has demonstrated that abiogenic alkane gases are of a promising resource, and it provides an example for the investigation of and search for abiogenic commercial natural gases worldwide.
文摘This book is a diary-style firsthand record written by Teacher Li Zhenxi,capturing in detail the raw educational events and authentic feelings he experienced during his time at school,and truly reconstructing the daily growth of both Teacher Li and the children.The content is vivid and engaging,with strong readability and compelling impact,presenting over one hundred“class leadership crosssections”from the perspective of a frontline class head,making it a riveting“class leadershipepic”.
