Spatial and Temporal Distinction of Microelemental Signatures of Missouri River Tributaries

The microchemical composition of a fish's calcified structure, such as an otolith, fin ray, or scale, is a ‘biological tag’ that reflects the use of different habitats throughout its life history. Hard‐part microchemistry has the potential to address many fish conservation, management, and behavior questions. In order to use hard‐part microchemistry to address fisheries research questions, elemental signatures of water must be distinct at the spatial scale of interest and ideally temporally stable. The goal of this study was to assess whether spatial differences existed in the concentrations of five elements [barium (¹³⁷Ba), magnesium (²⁴Mg), manganese (⁵⁵Mn), sodium (²³Na), and strontium (⁸⁸Sr)] between and within eight Missouri River tributaries and whether those signatures were temporally stable. All elemental concentrations were converted to molar ratios (mmol mol^?1) using calcium (⁴³Ca) concentrations as the base. Canonical correspondence analysis showed distinct differences in Mg:Ca, Na:Ca, and Sr:Ca concentrations between the eight tributaries. Cochran–Mantel–Haenszel tests showed that sites within a tributary were distinguished using Mg:Ca and Na:Ca concentrations. However, only Mg:Ca concentrations were temporally stable. Results from this study demonstrate the potential for using hard‐part microchemistry to address various questions at multiple spatial scales in the Missouri River riverscape but also highlight the importance of evaluating water microelemental signatures prior or simultaneous to any hard‐part microchemistry study. Copyright © 2016 John Wiley & Sons, Ltd.     

The annual cycle of Flehmen in black-tailed deer (Odocoileus hemionus columbianus)

Flehmen is a stereotyped response of ungulates and other mammals to urine. In black-tailed deer, Flehmen occurs typically in males (rarely in females), and its frequency shows an annual cycle. Flehmen in response to female urine was most frequent in November, and to male urine in January. The response minimum to both types of urine occurred in May. Fifty-five to 100% of initial responses to female urine resulted in Flehmen. The deer responded more often to female urine, and the difference between the responses to female and male urine increased from May to November. A male's own urine released Flehmen more often than did urine of other males. The response intensity varied with the spatial orientation of the male to the urinating female, and responses were usually limited to distances of 15 m or less.     

一类考虑病毒发生变异的SIS疾病传播模型

为了研究变异行为对病毒传播的影响,提出了一个病毒发生变异的疾病传播模型,在模型中考虑了两种病毒相互转换的过程,计算机模拟结果表明,两种病毒的稳态感染比例与它们之间的相互转换概率γ1和γ2有关,当γ1＞0且γ2=0时,I1型感染者将消失,当γ1与γ2都大于0时,I1/I2与γ1/γ2成反比,且与α1/β1和α2/β2的取值无关.研究还发现病毒变异时由于缺乏对应的治疗药物和措施而出现一段真空期,这导致变异病毒的感染比例快速增加,但真空期的出现只能增加感染者的瞬时感染比例,而对稳态感染比例没有影响.该研究对人们深入理解病毒传播机理具有启发作用.     

LDE融合光谱回归分类的光照变化人脸识别

针对光照变化人脸识别问题中传统的光谱回归算法不能很好地进行特征提取而严重影响识别性能的问题,提出了局部判别嵌入优化光谱回归分类的人脸识别算法。计算出训练样本的特征向量;借助于数据的近邻和分类关系,利用局部判别嵌入算法构建分类问题所需的嵌入,同时学习每种分类的子流形所需的嵌入;利用光谱回归分类算法计算投影矩阵,并利用最近邻分类器完成人脸的识别。在两大人脸数据库扩展YaleB及CMU PIE上的实验验证了该算法的有效性,实验结果表明,相比其他光谱回归算法,该算法取得了更高的识别率、更好的工作特性,并且降低了计算复杂度。     

基于FBG传感器网络的煤矿巷道在线监测系统设计

在掘进和采煤的过程中,巷道围岩的受力情况复杂多变,因此,巷道离层位移和围岩压力的实时监测是保证巷道正常工作的一个重要因素。设计了一种基于FBG传感器网络的煤矿巷道在线监测系统。该系统实现井下700 m数据采集,井上分析处理,可提供时序趋势变化、结构分布变化和阈值报警等功能。根据朱仙庄煤矿巷道的特点,系统安装4只FBG位移传感器、4只FBG土压力传感器和4只FBG温度传感器,对巷道掘进区域的离层位移、围岩压力和温度变化进行在线监测。监测结果表明:系统对离层位移、围岩压力和巷道温度变化反映灵敏,能够有效保证巷道掘进的正常进行,且为后续巷道施工提供数据支持和理论依据。     

Spatial and temporal variability in lake trout diets in Lake Ontario as revealed by stomach contents and stable isotopes

Lake trout (Salvelinus namaycush) are an ecologically and economically important piscivore with reported differences in diet and feeding behaviour throughout its range. Eleven stomach content and stable isotope-based metrics were used to describe diets of 349 lake trout between two years (2013 and 2018) and among geographic zones (west, central, east, Kingston basin) in Lake Ontario. Using individual (e.g., volumetric, %V) and aggregate (e.g., index of relative importance, %IRI) diet metrics, we found an overwhelming dominance of alewife (Alosa pseudoharengus) in lake trout diets among some zones in 2013 (%V = 23.3 – 92.7; %IRI = 12.2 – 99.5) and all zones in 2018 (%V = 83.9 – 96.7; %IRI = 96.5 – 100). Round goby (Neogobius melanostomus) and rainbow smelt (Osmerus mordax) were secondary lake trout prey items with relative diet percentages only marginally reflected by spatial and temporal variation in prey abundance (round goby: %V = 1.0 – 33.3, %IRI = 0.1 – 13.2; rainbow smelt: %V = 2.5 – 54.0, %IRI = 0.1 – 54.0). Carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic niche areas and orientations were similar across all year-zone combinations reinforcing temporal and spatial consistency in lake trout diet. The findings of this study advance the time series in describing Lake Ontario lake trout diets and can be used to complement stock assessments and management decisions associated with carrying capacity for the diverse salmonid community.     

基于引力搜索算法的分数阶变异时序回归GSA-TSGM(1,1)模型

为了利用分数阶累加算子在灰色短期预测中的高效性能,首次将分数阶累加算子引入变异时序回归模型以期取得更高的预测精度。主要方法如下：首先取湖北省链子崖某监测点1978—1987年的十年数据作为训练集并使用引力搜索算法确定最佳分数阶累加阶数,而1988—1993年的六年数据作为验证集验证提出的模型;其次对比了经典灰色模型GM(1,1)、分数阶累加灰色模型、变异时序回归模型TSGM(1,1)三种灰色模型。结果如下：首先修正了陈西江等人变异时序回归模型仿真时出现的错误,其次表明了相比于其他的模型,基于引力搜索算法的分数阶累加时序回归模型在进行灰色长期预测中具有较高的预测精度。因此,通过分数阶累加算子提高了灰色理论中长期预测模型的精度,为灰色长期预测提供了指导。     

怒江流域云南区段降雨时空变化分析

利用怒江流域云南区段及其毗邻地区77个站点1980~2009年雨量资料,以及怒江干流道街坝站1957~2015年和南汀河支流姑老河站1960~2015年降雨、径流资料,研究该流域降雨区域分异特征及变化趋势。结果表明:怒江流域云南区段多年平均面雨量达1 336.7 mm,远大于全省平均降雨量;怒江干流云南区段上游贡山地区和下游支流苏帕河流域,以及支流南汀河流域下游多年平均降雨量达1 500 mm以上,而干流的中游怒江坝干热河谷不足1 000 mm,降水空间分布格局与西南季风强弱及纵向岭谷地形密切相关;怒江流域云南区段降水量呈下降趋势,与怒江上游西藏区域相反,支流南汀河流域面雨量减少速率(56 mm/10 a)大于怒江干流云南区段(29 mm/10 a);怒江流域云南区段夏季降水占全年降水量的51%,怒江干流云南区段与支流南汀河流域降水量差异主要表现在夏季;怒江流域云南区段春季降水量呈增加趋势,夏季、秋季和冬季降水量呈减少趋势;怒江干流道街坝站、支流南汀河姑老河站降雨量长周期分别为36 a和33 a左右,从降雨变化长周期来看,2002年以来的少水期将持续到2018~2020年。怒江干流云南区段降水量变化的Hurst指数值为0.69,表明其未来趋势与过去一致,仍将延续降水量减少的变化趋势。     

鄱阳湖流域水分盈亏时空变化特征分析

根据1960~2014年鄱阳湖流域13个气象站点的气象资料,采用FAO推荐的Penman-Monteith法、Mann-Kendall趋势检验法和相关分析法,研究鄱阳湖流域水分盈亏量时空分布变化趋势及其与气象因子的关系。研究结果表明:鄱阳湖流域近55 a来水分盈亏量多年平均盈余为565.88 mm,空间上呈由西北向东北和由西南向东北逐渐递增的趋势;水分盈亏量年内分布呈秋季亏缺,其他季节盈余,水分盈余量表现为春季夏季冬季秋季;在研究时段内流域各地水分盈余量均呈增加趋势,但各季节水分盈余量变化存在一定的差异性,其中春季和秋季呈减少趋势,但趋势不明显,而夏季和冬季均呈显著的增加趋势(p0.05)。鄱阳湖流域水分盈亏量与降雨、日照时数和日最高气温关系密切,流域年水分盈余量的增加是由于夏季和冬季降水量的增加、日照数和风速的减少。     

岩石节理三维粗糙度各向异性表征新方法

针对传统二维节理面粗糙度表征方法的不足,提出一种新的岩石节理面三维粗糙度描述方法。首先,利用光学扫描系统得到节理表面点云数据并建立三维模型;运用改进的变异函数方法,提出一种新的基于正态分布模型参数的三维粗糙度(VA)方法;最后,运用新方法对花岗岩张拉型节理表面的粗糙特性进行分析。结果表明,提出的新方法能够反映节理面的起伏变化、频率和分形特征,并因此能描述出节理粗糙度的各向异性特性。