高速列车载客量大、运行时间长,通风系统的优化设计对于提高乘车舒适性和客室空气品质具有重要意义.基于计算流体动力学理论(CFD),建立了满载工况的全尺寸车厢模型.以客室顶部中间送风为例,针对两端排风、下端排风、上端排风以及改变两...高速列车载客量大、运行时间长,通风系统的优化设计对于提高乘车舒适性和客室空气品质具有重要意义.基于计算流体动力学理论(CFD),建立了满载工况的全尺寸车厢模型.以客室顶部中间送风为例,针对两端排风、下端排风、上端排风以及改变两侧排风流量比的上端排风,对比分析了客室内的流场结构以及呼吸污染物扩散特性.采用不均匀系数、能量利用系数、通风效率指标进行评价分析.结果表明,采用改进后的上端排风方式时,客室内的综合评价指标最优,室内平均浓度不足500 ppm(parts per million),稀释倍数超过10000倍.当乘客与污染源向前间隔超过两排或者向后间隔超过一排时,污染物浓度降低至500 ppm以下,可以有效控制前后扩散距离.根据污染物扩散规律,为进一步阻止乘客之间的交叉传播,应避免第B列与第C列乘客相邻乘坐.展开更多
Objective:Amphenicols(chloramphenicol,thiamphenicol and forfenicol)can cause aplastic anaemia and other severe side effects to consumers;therefore,it is necessary to inspect their residues in foods of animal origin.Ho...Objective:Amphenicols(chloramphenicol,thiamphenicol and forfenicol)can cause aplastic anaemia and other severe side effects to consumers;therefore,it is necessary to inspect their residues in foods of animal origin.However,there has been no report on the use of amphenicols receptor for the determination of their residues,and none of the previously reported immunoassays for amphenicols can differentiate the specifc species.Materials and Methods:In this study,the ribosomal protein L16 of Escherichia coli was frst expressed,and its intermolecular interaction mechanisms with the three amphenicols was studied using the molecular docking technique.The protein was then combined with three enzymelabelled conjugates to develop a direct competitive array on microplate for determination of the three drugs in egg.Results:Due to the use of principal component analysis to analyse the data,this method could discriminate the three drugs in the range 0.1–10 ng/mL,and the limits of detection for the three drugs were in the range of 0.0002–0.0009 ng/mL.The analysis results for the unknown egg samples were consistent with a liquid chromatography–tandem mass spectrometry method,and the method performances were superior to the previous immunoassays for amphenicols.Conclusion:This is the frst paper reporting the use of ribosomal protein L16 to develop a competitive array for discriminative determination of amphenicols in food samples.展开更多
文摘高速列车载客量大、运行时间长,通风系统的优化设计对于提高乘车舒适性和客室空气品质具有重要意义.基于计算流体动力学理论(CFD),建立了满载工况的全尺寸车厢模型.以客室顶部中间送风为例,针对两端排风、下端排风、上端排风以及改变两侧排风流量比的上端排风,对比分析了客室内的流场结构以及呼吸污染物扩散特性.采用不均匀系数、能量利用系数、通风效率指标进行评价分析.结果表明,采用改进后的上端排风方式时,客室内的综合评价指标最优,室内平均浓度不足500 ppm(parts per million),稀释倍数超过10000倍.当乘客与污染源向前间隔超过两排或者向后间隔超过一排时,污染物浓度降低至500 ppm以下,可以有效控制前后扩散距离.根据污染物扩散规律,为进一步阻止乘客之间的交叉传播,应避免第B列与第C列乘客相邻乘坐.
基金the National Natural Science Foundation of China(No.32372447)the Natural Science Foundation of Hebei Province(No.C2023204045),China.
文摘Objective:Amphenicols(chloramphenicol,thiamphenicol and forfenicol)can cause aplastic anaemia and other severe side effects to consumers;therefore,it is necessary to inspect their residues in foods of animal origin.However,there has been no report on the use of amphenicols receptor for the determination of their residues,and none of the previously reported immunoassays for amphenicols can differentiate the specifc species.Materials and Methods:In this study,the ribosomal protein L16 of Escherichia coli was frst expressed,and its intermolecular interaction mechanisms with the three amphenicols was studied using the molecular docking technique.The protein was then combined with three enzymelabelled conjugates to develop a direct competitive array on microplate for determination of the three drugs in egg.Results:Due to the use of principal component analysis to analyse the data,this method could discriminate the three drugs in the range 0.1–10 ng/mL,and the limits of detection for the three drugs were in the range of 0.0002–0.0009 ng/mL.The analysis results for the unknown egg samples were consistent with a liquid chromatography–tandem mass spectrometry method,and the method performances were superior to the previous immunoassays for amphenicols.Conclusion:This is the frst paper reporting the use of ribosomal protein L16 to develop a competitive array for discriminative determination of amphenicols in food samples.
