The activity of components of Sn-Zn binary alloy system was predicted based on the molecular interaction volume model （MIVM）. The calculated values are in good agreement with available experimental data of activitie...The activity of components of Sn-Zn binary alloy system was predicted based on the molecular interaction volume model （MIVM）. The calculated values are in good agreement with available experimental data of activities, which indicates that this model is of stability and reliability because the MIVM has a good physical basis. The vapor-liquid phase equilibrium of Sn-Zn alloy system in vacuum distillation was calculated as a function of the activity coefficient. The results show that the content of Sn in vapor phase is 4.2x 10-7 （mass fraction） while in liquid phase it is 90% （mass fraction） at 1 073 K, and the content of Sn in vapor phase increases with increasing the melt temperature and content of Sn in liquid phase. Vacuum distillation experiments were carried out on Sn-Zn alloy for the proper interpretation of the results of the MIVM in the temperature range of 973-1 273 K under pressures of 15-200 Pa. The experimental results show that the content of Sn in vapor phase is 5x 10 6 （mass fraction） while in liquid phase it is 90% （mass fraction） under the operational condition of 1 073 K, 100 rain and 15 Pa. The experimental results are in good agreement with the predicted values of the MIVM for Zn-Sn binary alloy system.展开更多
为精确刻画匝道合流区客货混行条件下的车辆微观换道行为,本文以量化客货交互为切入点,构建并验证考虑货车影响的微观换道模型。首先,引入“压迫”概念,构建改进Morse势函数模型描述周边货车行驶对小汽车横纵驾驶行为产生的“压迫”影响...为精确刻画匝道合流区客货混行条件下的车辆微观换道行为,本文以量化客货交互为切入点,构建并验证考虑货车影响的微观换道模型。首先,引入“压迫”概念,构建改进Morse势函数模型描述周边货车行驶对小汽车横纵驾驶行为产生的“压迫”影响;随后,分析小汽车换道过程中的横纵向“压迫”变化,提出一种考虑货车“压迫”影响的车辆换道决策模型(Modified Morse-Based Lane-Changing model,MMBLC);最后,基于实测轨迹数据进行数值仿真,验证模型的稳定性与有效性,并进一步利用Python与SUMO(Simulation of Urban Mobility)联合仿真,对比MMBLC模型和现有换道模型在交通流中的表现。结果表明:在稳定性分析中,MMBLC模型对交通流的影响更小,恢复稳定的速度更快;在货车占比30%和交通量3600 veh·h-1的主路3车道客货混行匝道合流区中,MMBLC模型相比LC2013和MOBIL(Model of Optimal Control Based on Interacting Trajectories)模型,换道成功率分别提高11.9%和53.1%,危险场景占比分别降低10.5%和52.8%。展开更多
The Hypocrea lixii/Trichoderma harzianum species aggregate contains a group of taxa (H. lixii /T. harzianum, T. aggressivum, T. tomentosum, T. cerinum, T. velutinum, H. tawa) of which some (e.g. T. harzianum) are impo...The Hypocrea lixii/Trichoderma harzianum species aggregate contains a group of taxa (H. lixii /T. harzianum, T. aggressivum, T. tomentosum, T. cerinum, T. velutinum, H. tawa) of which some (e.g. T. harzianum) are important for biocontrol of plant pathogenic fungi in agriculture, whereas others are aggressive pathogens of Agaricus spp. and Pleurotus spp. in mushroom farms (T. aggressivum), or opportunistic pathogens of immunocompromised mammals including humans (T. harzianum). We characterized the evolutionary properties of three genomic regions in Hypocrea/Trichoderma: the internal transcribed spacer regions ITS1 and 2 of rDNA, the large intron of translation elongation factor 1-alpha (tef1a), and a portion of the large exon of the endochitinase 42 gene (ech42), selected the best model which describes the evolution of every fragment, tested the molecular clock hypothesis and made an estimation of the usability of the combined three fragments data matrix for the phylogenetic analysis of the genus as a whole as well as on the level of the holomorphic H. lixii/T. harzianum species clade and separate clonal lineages. To this end, we applied Bayesian phylogenetic inferences to 124 sequences of ITS1 and 2 and of the large tef1a intron, and to 64 ech42 gene sequences to resolve the evolution of H. lixii/T. harzianum with respect to the position of other taxa with closely related phenotypes. The resulting phylogram clearly identified T. aggressivum, T. velutinum, H. tawa, T. cerinum and T. tomentosum as phylogenetic species, and in addition identified three new unknown phylogenetic species as members of this clade. The clear distinction between T. tomentosum and T. cerinum was not recognized in all trees, but was supported by multivariate analysis of phenotype micro arrays. In contrast, H. lixii/T. harzianum did not form a single phylogenetic species in this study, as its monophyly was not supported in any analysis. Strains morphologically identified as H. lixii or T. harzianum formed either a proliferating megaclade (three loci combined tree) or appeared as several independent branches on the star-like phylogram (ITS1 and 2 and large tef1a intron) . However most terminal clades had a high posterior probability and thus fulfilled the criterion to consider their member isolates as a phylogenetic species. The clade containing the ex-neotype strain of T. harzianum included exclusively clonally propagating isolates from temperate climates, and was clearly distinguished from all other “H. lixii/T. harzianum” lineages by multivariate analysis of phenotype microarray data. We propose that only this lineage should be regarded as T. harzianum sensu stricto, and that the other lineages be regarded as T. harzianum sensu lato until phenetic characters have been defined which allow their description as separate taxa.展开更多
煤焦的反应性受其化学结构影响,该文基于碳-13固体核磁共振(^(13)C solid-state nuclear magnetic resonance,^(13)C-NMR)技术构建了准东脱灰煤焦大分子结构模型,采用反应力场分子动力学模拟方法(reactive force field molecular dynami...煤焦的反应性受其化学结构影响,该文基于碳-13固体核磁共振(^(13)C solid-state nuclear magnetic resonance,^(13)C-NMR)技术构建了准东脱灰煤焦大分子结构模型,采用反应力场分子动力学模拟方法(reactive force field molecular dynamics,ReaxFF MD)对准东脱灰煤焦在O_(2)/H_(2)O条件下的燃烧过程进行模拟。结果表明:不同O_(2)/H_(2)O浓度下,C+H_(2)O气化和C+O_(2)氧化反应相互竞争,O、H、OH自由基对准东脱灰煤焦活性位的竞争程度不同。压力越高,则C+O_(2)氧化反应较C+H_(2)O气化反应的化学活性越大,燃烧程度也越深,故温度升高有利于提高煤焦的燃烧转化率、缩短燃尽时间。准东脱灰煤焦燃烧始于侧支链及脂肪碳的分解,随后稠环芳烃开环断裂为小分子结构碎片,与活性自由基相互作用形成燃烧产物。该文从分子层面直观地追踪了燃烧的中间产物及演变过程,有利于深入理解燃烧机理,为后续燃烧技术及应用提供理论支持。展开更多
基金Project(2012CB722803) supported by the Key Project of National Basic Research and Development Program of ChinaProject(2011FA008)supported by the Key Project of Science and Technology Program of Yunnan Province,China
文摘The activity of components of Sn-Zn binary alloy system was predicted based on the molecular interaction volume model （MIVM）. The calculated values are in good agreement with available experimental data of activities, which indicates that this model is of stability and reliability because the MIVM has a good physical basis. The vapor-liquid phase equilibrium of Sn-Zn alloy system in vacuum distillation was calculated as a function of the activity coefficient. The results show that the content of Sn in vapor phase is 4.2x 10-7 （mass fraction） while in liquid phase it is 90% （mass fraction） at 1 073 K, and the content of Sn in vapor phase increases with increasing the melt temperature and content of Sn in liquid phase. Vacuum distillation experiments were carried out on Sn-Zn alloy for the proper interpretation of the results of the MIVM in the temperature range of 973-1 273 K under pressures of 15-200 Pa. The experimental results show that the content of Sn in vapor phase is 5x 10 6 （mass fraction） while in liquid phase it is 90% （mass fraction） under the operational condition of 1 073 K, 100 rain and 15 Pa. The experimental results are in good agreement with the predicted values of the MIVM for Zn-Sn binary alloy system.
文摘为精确刻画匝道合流区客货混行条件下的车辆微观换道行为,本文以量化客货交互为切入点,构建并验证考虑货车影响的微观换道模型。首先,引入“压迫”概念,构建改进Morse势函数模型描述周边货车行驶对小汽车横纵驾驶行为产生的“压迫”影响;随后,分析小汽车换道过程中的横纵向“压迫”变化,提出一种考虑货车“压迫”影响的车辆换道决策模型(Modified Morse-Based Lane-Changing model,MMBLC);最后,基于实测轨迹数据进行数值仿真,验证模型的稳定性与有效性,并进一步利用Python与SUMO(Simulation of Urban Mobility)联合仿真,对比MMBLC模型和现有换道模型在交通流中的表现。结果表明:在稳定性分析中,MMBLC模型对交通流的影响更小,恢复稳定的速度更快;在货车占比30%和交通量3600 veh·h-1的主路3车道客货混行匝道合流区中,MMBLC模型相比LC2013和MOBIL(Model of Optimal Control Based on Interacting Trajectories)模型,换道成功率分别提高11.9%和53.1%,危险场景占比分别降低10.5%和52.8%。
文摘The Hypocrea lixii/Trichoderma harzianum species aggregate contains a group of taxa (H. lixii /T. harzianum, T. aggressivum, T. tomentosum, T. cerinum, T. velutinum, H. tawa) of which some (e.g. T. harzianum) are important for biocontrol of plant pathogenic fungi in agriculture, whereas others are aggressive pathogens of Agaricus spp. and Pleurotus spp. in mushroom farms (T. aggressivum), or opportunistic pathogens of immunocompromised mammals including humans (T. harzianum). We characterized the evolutionary properties of three genomic regions in Hypocrea/Trichoderma: the internal transcribed spacer regions ITS1 and 2 of rDNA, the large intron of translation elongation factor 1-alpha (tef1a), and a portion of the large exon of the endochitinase 42 gene (ech42), selected the best model which describes the evolution of every fragment, tested the molecular clock hypothesis and made an estimation of the usability of the combined three fragments data matrix for the phylogenetic analysis of the genus as a whole as well as on the level of the holomorphic H. lixii/T. harzianum species clade and separate clonal lineages. To this end, we applied Bayesian phylogenetic inferences to 124 sequences of ITS1 and 2 and of the large tef1a intron, and to 64 ech42 gene sequences to resolve the evolution of H. lixii/T. harzianum with respect to the position of other taxa with closely related phenotypes. The resulting phylogram clearly identified T. aggressivum, T. velutinum, H. tawa, T. cerinum and T. tomentosum as phylogenetic species, and in addition identified three new unknown phylogenetic species as members of this clade. The clear distinction between T. tomentosum and T. cerinum was not recognized in all trees, but was supported by multivariate analysis of phenotype micro arrays. In contrast, H. lixii/T. harzianum did not form a single phylogenetic species in this study, as its monophyly was not supported in any analysis. Strains morphologically identified as H. lixii or T. harzianum formed either a proliferating megaclade (three loci combined tree) or appeared as several independent branches on the star-like phylogram (ITS1 and 2 and large tef1a intron) . However most terminal clades had a high posterior probability and thus fulfilled the criterion to consider their member isolates as a phylogenetic species. The clade containing the ex-neotype strain of T. harzianum included exclusively clonally propagating isolates from temperate climates, and was clearly distinguished from all other “H. lixii/T. harzianum” lineages by multivariate analysis of phenotype microarray data. We propose that only this lineage should be regarded as T. harzianum sensu stricto, and that the other lineages be regarded as T. harzianum sensu lato until phenetic characters have been defined which allow their description as separate taxa.
文摘煤焦的反应性受其化学结构影响,该文基于碳-13固体核磁共振(^(13)C solid-state nuclear magnetic resonance,^(13)C-NMR)技术构建了准东脱灰煤焦大分子结构模型,采用反应力场分子动力学模拟方法(reactive force field molecular dynamics,ReaxFF MD)对准东脱灰煤焦在O_(2)/H_(2)O条件下的燃烧过程进行模拟。结果表明:不同O_(2)/H_(2)O浓度下,C+H_(2)O气化和C+O_(2)氧化反应相互竞争,O、H、OH自由基对准东脱灰煤焦活性位的竞争程度不同。压力越高,则C+O_(2)氧化反应较C+H_(2)O气化反应的化学活性越大,燃烧程度也越深,故温度升高有利于提高煤焦的燃烧转化率、缩短燃尽时间。准东脱灰煤焦燃烧始于侧支链及脂肪碳的分解,随后稠环芳烃开环断裂为小分子结构碎片,与活性自由基相互作用形成燃烧产物。该文从分子层面直观地追踪了燃烧的中间产物及演变过程,有利于深入理解燃烧机理,为后续燃烧技术及应用提供理论支持。
