A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hyd...A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hydrolysed to corresponding carboxylic acid under dilute acidic condition, intramolecular cycle addition of this acid afforded bicyclo lactone. Treatment of 5 with pyridine and POCl3 to afford product dehydroration by the trifluoromethyl substituted α,β-unsaturated carbonyl compound 6.4- Trifluoroacetyl 2,3-dihydro-2H-furan behaves similar compounds 8, 9 and 10 are prepared.展开更多
The purpose of this project is to control the pollution of dust,which occurred in a typical lead-zinc mine.Two kinds of surfactants and water glass were chosen as the wetting agents to study the behaviours of suppress...The purpose of this project is to control the pollution of dust,which occurred in a typical lead-zinc mine.Two kinds of surfactants and water glass were chosen as the wetting agents to study the behaviours of suppressing the dust.The performances of the wetting agents of various sizes and water content of dust and their compositions among different weting agents were investigated. Firstly,the chemical compounds,dispersity,water content,bulk density and other relevant physico-chemical properties of the choiced dust of lead-zinc ore were mensurated.A great number of down-ward penetrating tests were conducted to different partical sizes of dust and to analyze the dust wetting behaviour respectively.The optimal compositions of wetting agents were obtained in accordance with different water contents and partical sizes of the dust after analyzing and statisting the achieved experimental data. The data show that the efficiency of chemical dust suppression of weting agents is much better than that of water.The results of the research work prove that the partical size and the water content of the dust are very important factors to the dust suppression.The results are also proved validly by the dropping experiment,which takes the penetrating diameter and penetrating time as the major factors.The superfine dust is much more difficult to be wetted.Since increasing the water content of dust is the best approach to control it,the choice of wetting agents for improving dispensation is significant.展开更多
硒化锌多晶陶瓷是研发高性能光电子器件的关键原材料,对该陶瓷材料金相检验的腐蚀方法进行研究,采用60 mL浓硫酸+40 mL乙酸、20 mL HNO3+10 mL HF+20 mL水、5 g FeCl3+50 mL浓盐酸+100 mL水、95 mL浓盐酸+5 mL H2O2、100 mL浓盐酸蒸汽...硒化锌多晶陶瓷是研发高性能光电子器件的关键原材料,对该陶瓷材料金相检验的腐蚀方法进行研究,采用60 mL浓硫酸+40 mL乙酸、20 mL HNO3+10 mL HF+20 mL水、5 g FeCl3+50 mL浓盐酸+100 mL水、95 mL浓盐酸+5 mL H2O2、100 mL浓盐酸蒸汽腐蚀等方法对硒化锌金相试样表面进行腐蚀。结果表明:采用100 mL浓盐酸蒸汽腐蚀硒化锌试样表面时获得的显微组织晶界轮廓明显、晶粒形貌显示清晰,有利于开展硒化锌多晶陶瓷材料的显微组织均匀性分析、晶粒度评定等工作。展开更多
基金The authors thank the National Natural ScienceFoundation of China (NNSFC)! (No. 29872051 and No. 29672041 )for financial support
文摘A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hydrolysed to corresponding carboxylic acid under dilute acidic condition, intramolecular cycle addition of this acid afforded bicyclo lactone. Treatment of 5 with pyridine and POCl3 to afford product dehydroration by the trifluoromethyl substituted α,β-unsaturated carbonyl compound 6.4- Trifluoroacetyl 2,3-dihydro-2H-furan behaves similar compounds 8, 9 and 10 are prepared.
基金Project(50474050)supported by the National Natural Science Foundation of ChinaProject(20040533011)supported by the Doctorate Program Fund of Ministry of Education,China
文摘The purpose of this project is to control the pollution of dust,which occurred in a typical lead-zinc mine.Two kinds of surfactants and water glass were chosen as the wetting agents to study the behaviours of suppressing the dust.The performances of the wetting agents of various sizes and water content of dust and their compositions among different weting agents were investigated. Firstly,the chemical compounds,dispersity,water content,bulk density and other relevant physico-chemical properties of the choiced dust of lead-zinc ore were mensurated.A great number of down-ward penetrating tests were conducted to different partical sizes of dust and to analyze the dust wetting behaviour respectively.The optimal compositions of wetting agents were obtained in accordance with different water contents and partical sizes of the dust after analyzing and statisting the achieved experimental data. The data show that the efficiency of chemical dust suppression of weting agents is much better than that of water.The results of the research work prove that the partical size and the water content of the dust are very important factors to the dust suppression.The results are also proved validly by the dropping experiment,which takes the penetrating diameter and penetrating time as the major factors.The superfine dust is much more difficult to be wetted.Since increasing the water content of dust is the best approach to control it,the choice of wetting agents for improving dispensation is significant.
文摘硒化锌多晶陶瓷是研发高性能光电子器件的关键原材料,对该陶瓷材料金相检验的腐蚀方法进行研究,采用60 mL浓硫酸+40 mL乙酸、20 mL HNO3+10 mL HF+20 mL水、5 g FeCl3+50 mL浓盐酸+100 mL水、95 mL浓盐酸+5 mL H2O2、100 mL浓盐酸蒸汽腐蚀等方法对硒化锌金相试样表面进行腐蚀。结果表明:采用100 mL浓盐酸蒸汽腐蚀硒化锌试样表面时获得的显微组织晶界轮廓明显、晶粒形貌显示清晰,有利于开展硒化锌多晶陶瓷材料的显微组织均匀性分析、晶粒度评定等工作。
基金the financial supports from the National Natural Science Foundation of China(No.U20A20273)the National Key R&D Program of China(No.2019YFC1907400)+1 种基金the Science and Technology Innovation Program of Hunan Province,China(No.2021RC3005)the Natural Science Fund for Distinguished Young Scholar of Hunan Province,China(No.2022JJ10078)。
