面向设计的地铁车站防火安全韧性评价*

为提升地铁车站防火安全韧性,以设计方案为切入视角,基于防火安全韧性的吸收、抵抗、恢复和适应能力4个维度,构建基于ANP-熵权法面向设计的地铁防火安全韧性评价指标体系,运用逼近理想解法建立地铁车站防火安全韧性设计评价模型,通过3个已建地铁车站（青岛、沈阳、福州某地铁车站）的设计案例验证该模型的有效性和可行性。研究结果表明:3个应用案例中,沈阳某地铁车站设计防火安全韧性最高,福州某地铁车站设计防火安全韧性最低,需进一步提升防火安全能力。评价结果与各案例的实际运行阶段基本吻合,研究思路和结果对改善地铁车站的防火安全设计具有一定参考意义。     

模糊物元评价方法在水库移民安置区优选中的应用

本文在模糊物元分析的基础上,结合模糊相似贴近度的概念,将基于模糊相似贴近度的模糊物元分析应用到水库移民安置区优选中,并根据GIS中图层叠加方法,在多种约束条件下对备选水库移民安景区进行初步的筛选,满足基本约束条件的要求,减轻了初选工作量.在指标权重方面,采用层次分析法和熵值法相结合的方法计算评判指标权重,提高了对移民安置区评判准确度和可信度.最后,将该优化选择模型应用于南水北调工程丹江口库区移民试点优选外迁安置区中,从应用的过程和对计算结果的分析来看,该方法在实践中效果较好,并可推广应用到整个库区外迁移民安置过程中,实现了移民淹没区和安置区优化配置,确保了移民"搬得出、稳得住、逐步能致富"的目标.     

古田山国家自然保护区黄山松林主要种群生态位研究

采用样方法进行调查,每个样地面积为20m×20m。测度主要种群的生态位宽度、生态位相似比例、生态位重叠值。结果表明,黄山松、木荷、野漆树、甜槠等有较大的生态位宽度,其Levins生态位宽度(Bi值)和Hurlbert生态位宽度(Ba值)分别为0.7619、0.6517、0.5886、0.5384和0.9175、0.6278、0.5571、0.4377;野鸭椿的生态位宽度最小,其Bi值和Ba值分别为0.3655和0.2343。黄山松、木荷、野漆树、甜槠等生态位宽度较大的树种,生态位相似性比例高;而生态位宽度较小的物种,生态位相似性比例较小。黄山松、木荷、野漆树、甜槠等生态位宽度较大种群之间具有较大的生态位重叠。     

Female tree swallows (<Emphasis Type="Italic">Tachycineta bicolor</Emphasis>) increase offspring heterozygosity through extrapair mating

Recent attention has focused on genetic compatibility as an adaptive function for why females engage in extrapair mating. We tested the genetic compatibility hypothesis in tree swallows (Tachycineta bicolor) over five breeding seasons using data from ten microsatellite loci. Tree swallows are socially monogamous passerines exhibiting high levels of extrapair paternity. Overall, we found that 47% of offspring were the result of extrapair fertilizations, and 83% of females produced at least one extrapair offspring. Consistently for all years, extrapair offspring were more heterozygous than their maternal half-siblings, which is in accordance with the genetic compatibility hypothesis. The difference was largely caused by the high heterozygosity of extrapair offspring sired by unknown males, suggesting that females are engaging in extrapair copulations with geographically distant males to increase the likelihood of being inseminated by a more compatible mate. Our findings support the idea that postcopulatory mechanisms are important for females when assessing potential sires for their offspring.     

Variability of turbulence dispersion characteristics during heavy haze process: A case study in Beijing

The turbulent standard deviations and the turbulent third-order and fourth-order moments are the key turbulence dispersion parameters in Lagrangian dispersion models. However, the characteristics of these parameters under heavy haze conditions in urban areas have not been fully investigated, and the commonly used similarity relations of these parameters in models were based on observations in highly flat and sparsely populated areas. In this paper, the vertical profiles of these parameters and their local similarity relations under heavy haze conditions in the wintertime of Beijing have been analyzed by using data collected at a 325-m meteorological tower. The heavy haze process has been divided into three stages: transport stage (TS), cumulative stage (CS), and dispersion stage (DS). Results show that the turbulent dispersion parameters behave differently during three stages. In the TS and DS, the maxima appear in the profiles of the turbulent standard deviations above the urban canopy; in the CS, the turbulent standard deviation are almost constant with height. The analysis of the third and fourth order moments shows that the wind velocities above the urban canopy in the TS deviate from the Gaussian distribution more significantly than those in the CS and DS. The local similarity relations of the turbulent dispersion parameters in the TS, especially for the longitudinal wind components, are normally different from those in the CS and DS. Thus, different from the common assumptions in Lagrangian models, the turbulence dispersion in horizontal directions is anisotropic and should be parameterized by multiple similarity relations under heavy haze conditions.     

基于改进FWA-NN的污水处理过程溶解氧浓度预测

为实现对污水处理过程溶解氧质量浓度的实时准确预测,提出了一种改进的混沌烟花混合优化算法并构建了基于改进算法的神经网络在线软测量模型.结合污水处理过程的数据特征,定义了一项新的样本相似度衡量指标用于提取更具代表性的建模数据.在改进算法中,为提高基本烟花算法初始成员的质量,定义了一种改进的两级正弦混沌映射并利用混沌运动的遍历性精选烟花算法的初始群成员;通过融合混沌算法改进了基本烟花算法的搜索机制,基于设定准则将寻优过程分为两阶段并采用两分群同时进行.测试结果表明改进算法的收敛速度和收敛精度有较大程度提高.将改进的软测量建模方法和样本数据提取方法用于污水处理过程溶解氧质量浓度软测量建模,应用结果表明该模型的均方根误差和平均泛化误差分别为0.0175和0.0118,具有较强的泛化性能.     

民航不安全事件报告危险源识别模型

为了识别民航不安全事件的发生原因,从民航不安全事件报告出发,提出了一种基于LDA主题模型和Word2Vec模型的民航不安全事件报告危险源识别模型。首先,构建危险源标签分类表,选取民航不安全事件报告与Wiki中文数据库作为数据源,然后利用LDA主题模型得出民航不安全事件报告的主题概率分布与词概率分布,最后利用Wiki中文数据库训练Word2Vec模型得到词向量,进而计算文档主题与不同危险源标签之间的相似度,得出民航不安全事件报告的危险源分类。结果表明,该模型的精准率为77.7%、召回率为86.8%、F为82.0%,能够有效识别各民航不安全事件报告的危险源。     

洪水作用下汽车的起动流速研究

针对洪水作用下汽车的起动条件开展了一系列的研究:首先分析部分淹没状态下汽车的受力情况,结合滑动平衡的临界起动条件建立相关方程,导出了洪水中汽车起动流速公式;然后在室内水槽中对三款模型车进行了一系列的起动试验。试验结果表明:对于同一款模型车,平行于水流方向放置时,起动流速与水深的相关性较好;并且水深越大,起动流速越小。接着运用试验资料率定了起动流速公式中的相关参数。最后采用模型相似率及率定后的计算公式估算了原型车辆在不同水深下的起动流速,两种方法所得的结果较为接近,故预测结果较为可靠。     

Cytochrome P450 BM3 of Bacillus megaterium—A possible endosulfan biotransforming gene

Computing chemistry was applied to understand biotransforrnation mechanism of an organochlorine pesticide, endosulfan. The stereo specific metabolic activity of human CYP-2B6 （cytochrome P450） on endosulfan has been well demonstrated. Sequence and structural similarity search revealed that the bacterium Bacillus megaterium encodes CYP-BM3, which is similar to CYP-2B6. The functional similarity was studied at organism level by batch-scale studies and it was proved that B. megaterium could metabolize endosulfan to endosulfan sulfate, as CYP-2B6 does in human system. The gene expression analyses also confirmed the possible role of CYP-BM3 in endosulfan metabolism. Thus, our results show that the protein structure based in-silico approach can help us to understand and identify microbes for remediation strategy development. To the best of our knowledge this is the first report which has extrapolated the bacterial gene for endosulfan biotransformation through in silico prediction approach for metabolic gene identification.     

中国西南不同湿地类型水鸟多样性评价

水鸟是反映湿地生态系统健康的指标之一,对不同湿地水鸟多样性进行评价能提出有利于湿地生态系统健康良性发展的湿地管理措施,亦能更好地保护水鸟资源。为缓解近年来中国自然湿地退化和消失的问题,中国政府积极推进实施了大量修复自然湿地和新建人工湿地的工程。然而受限于人力、物力和经费,当前对自然湿地和人工湿地水鸟多样性的系统调查和评价多局限于单一地点或局部区域。因水鸟的分布具有地域性,从地域尺度进行不同湿地类型水鸟多样性评价将更为客观,公众科学数据为区域大尺度数据获取提供了可能。本研究借助中国观鸟记录中心数据,比较了2014年1月至2018年2月中国西南4省(市)自然湿地和人工湿地的水鸟物种多样性和组成相似性;结果共记录到9目19科139种水鸟,其中有94.96%的物种分布于自然湿地,67.63%的物种分布于人工湿地;各类群水鸟在自然湿地中的物种数均高于人工湿地。结果说明自然湿地在水鸟保护中具有重要栖息地功能,人工湿地能为大部分水鸟提供栖息地,但不能完全代替自然湿地。自然湿地中的湖泊湿地、河流湿地和沼泽化草甸以及人工湿地中的水库、城市人工景观水面和娱乐水面是水鸟,特别是受威胁水鸟分布的重要湿地类型;建议政府部门重点对上述湿地亚类进行合理的规划和管理。