A strain LHB02 with strong antibacterial activity against some aquatic pathogens was screened from the coastal marine sediment in Fujian province, China. LHB02 was identified as Bacillus subtilis, based on its 16S rRN...A strain LHB02 with strong antibacterial activity against some aquatic pathogens was screened from the coastal marine sediment in Fujian province, China. LHB02 was identified as Bacillus subtilis, based on its 16S rRNA sequence, together with the morphological, physiological and biochemical characteristics. The antagonistic activity of strain LHB02 and its optimal fermentation conditions were also investigated. The results showed that LHB02 had strong antagonistic activity against 3 species of vibrios: Vibrio harveyi,Vibrio alginolyticus and Vibrio anguillarum, and the optimum fermentation conditions for the strain LHB02 were as follows: KB culture medium (peptone 20 g, glycerol 10 mL, K2HPO4 1.5 g, MgSO 4 .7H2O 1.5 g, H2O 1 000 mL); temperature, 28 ℃; pH ,7.0; culture time, 36 h; and inoculation amount, 1.5% (v/v).展开更多
文摘列车运行图铺画与天窗设置存在相互影响,相互制约的耦合关系,为了达到优化列车运行图结构,合理配置铁路运力资源的目的,在分析天窗与列车运行动态影响关系的基础上,以天窗设置对列车运行线铺画影响最小为目标,建立了列车运行图与天窗协同优化的混合整数规划模型.考虑问题复杂性,设计了包含初步优化和综合优化的两阶段求解算法.初步优化阶段采用基于专家经验的启发式算法得到列车运行图的大体框架,综合优化阶段利用禁忌搜索算法获取全局最优解.最后以宝成线(阳平关—成都)为例进行有效性验算.结果表明,相较于人机交互编制所得运行图,优化得出的运行图中所有客货列车在途经车站的总停留时间降低了6.19%,共减少1355 min,其中旅客列车和货物列车在站停留时间分别降低了3.08%和7.40%,减少总时间分别为189 min和1166 min.
文摘高速铁路夕发朝至列车开行与天窗设置存在动态影响关系,将两者进行协同优化有助于满足旅客夜间出行需求,提升铁路运力资源配置.以通道型高速铁路为对象,在分析高速铁路夕发朝至列车与天窗设置影响关系的基础上,以高速铁路夕发朝至列车总的旅行时间最少和高速铁路夕发朝至列车的开行对既有列车运行图的影响最小为目标,建立了列车开行模式未定情形下高速铁路夕发朝至列车与天窗协同优化的非线性混合整数规划模型.结合问题特性,提出了双目标转换和约束线性化处理等模型约简策略,设计了基于自适应大邻域搜索的启发式求解算法.最后,以京广高速铁路走廊为例,对模型算法的有效性进行了验证.结果表明:算法经过40次左右迭代便可收敛至最优解,耗时784 s.
基金supported by the Scientific Research Foundation of Xiamen Marine Research and Development Institute (No. K10102 (1))
文摘A strain LHB02 with strong antibacterial activity against some aquatic pathogens was screened from the coastal marine sediment in Fujian province, China. LHB02 was identified as Bacillus subtilis, based on its 16S rRNA sequence, together with the morphological, physiological and biochemical characteristics. The antagonistic activity of strain LHB02 and its optimal fermentation conditions were also investigated. The results showed that LHB02 had strong antagonistic activity against 3 species of vibrios: Vibrio harveyi,Vibrio alginolyticus and Vibrio anguillarum, and the optimum fermentation conditions for the strain LHB02 were as follows: KB culture medium (peptone 20 g, glycerol 10 mL, K2HPO4 1.5 g, MgSO 4 .7H2O 1.5 g, H2O 1 000 mL); temperature, 28 ℃; pH ,7.0; culture time, 36 h; and inoculation amount, 1.5% (v/v).