A new condensation reaction of β-keto-δ-valerolactones was developed. The condensation products are composed of a pair of isomers because of the formation ofintramolecular hydrogen bond. Their structures were confir...A new condensation reaction of β-keto-δ-valerolactones was developed. The condensation products are composed of a pair of isomers because of the formation ofintramolecular hydrogen bond. Their structures were confirmed by 1HNMR and elemental analysis.展开更多
Foot-and-mouth disease(FMD)is an acute,highly infectious and pathogenic animal disease.In recent years,with the rapid development of the swine breeding industry in China,pig farms have shown a trend of larger-scale de...Foot-and-mouth disease(FMD)is an acute,highly infectious and pathogenic animal disease.In recent years,with the rapid development of the swine breeding industry in China,pig farms have shown a trend of larger-scale development.Large-scale pig farms employ standardized management,a high level of automation,and a strict_system.However,these farms have a large trading volume,and increased transmission intensity of FMD is noted inside the farm.At present,the main control measure against FMD is pig vaccination.However,a standard for immunization procedures is not available,and currently adopted immunization procedures have not been effectively and systematically evaluated.Taking a typical large-scale pig farm in China as the research subject and considering the breeding pattern,piggery structure,age structure and immunization procedures,an individual-based state probability model is established to evaluate the effectiveness of the immune procedure.Based on numerical simulation,it is concluded that the optimal immunization program involves primary immunization at 40 days of age and secondary immunization at 80 days of age for commercial pigs.Breeding boars and breeding sows are immunized 4 times a year,and reserve pigs are immunized at 169 and 259 days of age.According to the theoretical analysis,the average control reproduction number of individuals under the optimal immunization procedure in the farm is 0.4927.In the absence of immunization,the average is 1.7498,indicating that the epidemic cannot be controlled without immunization procedures.展开更多
Synthesis of a novel series of N-pyrandione substituted amino acids and their esters 3 via a condensation reaction between pyrandione and amino acid or their derivatives in excess ethyl orthoformate without solvent is...Synthesis of a novel series of N-pyrandione substituted amino acids and their esters 3 via a condensation reaction between pyrandione and amino acid or their derivatives in excess ethyl orthoformate without solvent is described. The stereochemistry of 3 has been discussed.展开更多
The chloromethylation reaction of substituted titanocenes (η~5-C_5H_5)(η~5-C_5H_4CRR'C_6H_4X)TiCl2 1 in the presence of polyformaldehyde and dry hydrogen chloride isreported.
Piperonyl methyl ketone was obtained by oxidizing isosafrole with hydrogen peroxide and formic acid. Dianion of ethyl acetoacetate reacted with piperonyl methyl ketone and 5, 6-dihydro-6-methyl-6-piperonyl-2H-pyran-2...Piperonyl methyl ketone was obtained by oxidizing isosafrole with hydrogen peroxide and formic acid. Dianion of ethyl acetoacetate reacted with piperonyl methyl ketone and 5, 6-dihydro-6-methyl-6-piperonyl-2H-pyran-2, 4-dione was prepared, which reacted with substituted anilines in the presence of ethyl orthoformate to obtain 3-anilinomethylene-5, 6- dihydro- 6-methyl-6-piperonyl-2H-pyran-2, 4-diones. Their structures were confirmed by 1HNMR and elemental analysis.展开更多
文摘A new condensation reaction of β-keto-δ-valerolactones was developed. The condensation products are composed of a pair of isomers because of the formation ofintramolecular hydrogen bond. Their structures were confirmed by 1HNMR and elemental analysis.
文摘Unexpected condensation products from β-keto-δ-valerolactones were obtained. Theirstructures were confirmed by 'HNMR spectrum and elemental analysis.
基金supported by the National Key Research and Development Program of China(2016YFD0501501)the National Natural Science Foundation of China under Grant(11601292,61873154,11801398)+4 种基金Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(20210009)General Youth Fund project in Shanxi Province(201901D211158)the 1331 Engineering Project of Shanxi Province,Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province(2019L0114)Key Projects of Health Commission of Shanxi Province(No.2020XM18)the Key Research and Development Project in Shanxi Province(202003D31011/GZ).
文摘Foot-and-mouth disease(FMD)is an acute,highly infectious and pathogenic animal disease.In recent years,with the rapid development of the swine breeding industry in China,pig farms have shown a trend of larger-scale development.Large-scale pig farms employ standardized management,a high level of automation,and a strict_system.However,these farms have a large trading volume,and increased transmission intensity of FMD is noted inside the farm.At present,the main control measure against FMD is pig vaccination.However,a standard for immunization procedures is not available,and currently adopted immunization procedures have not been effectively and systematically evaluated.Taking a typical large-scale pig farm in China as the research subject and considering the breeding pattern,piggery structure,age structure and immunization procedures,an individual-based state probability model is established to evaluate the effectiveness of the immune procedure.Based on numerical simulation,it is concluded that the optimal immunization program involves primary immunization at 40 days of age and secondary immunization at 80 days of age for commercial pigs.Breeding boars and breeding sows are immunized 4 times a year,and reserve pigs are immunized at 169 and 259 days of age.According to the theoretical analysis,the average control reproduction number of individuals under the optimal immunization procedure in the farm is 0.4927.In the absence of immunization,the average is 1.7498,indicating that the epidemic cannot be controlled without immunization procedures.
基金the National Natural Science Foundation of China for the project support (No.29832050)
文摘Synthesis of a novel series of N-pyrandione substituted amino acids and their esters 3 via a condensation reaction between pyrandione and amino acid or their derivatives in excess ethyl orthoformate without solvent is described. The stereochemistry of 3 has been discussed.
文摘The chloromethylation reaction of substituted titanocenes (η~5-C_5H_5)(η~5-C_5H_4CRR'C_6H_4X)TiCl2 1 in the presence of polyformaldehyde and dry hydrogen chloride isreported.
文摘Piperonyl methyl ketone was obtained by oxidizing isosafrole with hydrogen peroxide and formic acid. Dianion of ethyl acetoacetate reacted with piperonyl methyl ketone and 5, 6-dihydro-6-methyl-6-piperonyl-2H-pyran-2, 4-dione was prepared, which reacted with substituted anilines in the presence of ethyl orthoformate to obtain 3-anilinomethylene-5, 6- dihydro- 6-methyl-6-piperonyl-2H-pyran-2, 4-diones. Their structures were confirmed by 1HNMR and elemental analysis.
