Co-occurrence of three Aristolochia-feeding Papilionids (Archon apollinus,Zerynthia polyxena and Zerynthia cerisy) in Greek Thrace

Comparative studies of co-occurring species using overlapping resources may help in understanding the mechanisms supporting biotic diversity in species-rich regions, such as the Mediterranean region of Europe. Three Papilionidae butterflies, Archon apollinus, Zerynthia cerisy and Zerynthia polyxena, develop on Aristolochia plants and co-occur in Greek Thrace. We used mark–recapture to describe adult demography and dispersal, and searched for eggs and larvae to assess host plants and microhabitat preferences. Adult flight timing followed a sequence from earliest A. apollinus, through Z. polyxena to late Z. cerisy; this was more prominent in 2010 (warm early spring) than in 2011 (cold delayed spring). Population densities were highest for A. apollinus and lowest for Z. cerisy, whereas dispersal ability followed a reverse pattern. Adults of all three species crossed distances > 3 km and used all habitat types present. Four Aristolochia host plants were used at the study locality: small Aristolochia pallida, intermediate Aristolochia rotunda and Aristolochia hirta, and bulky, late-sprouting Aristolochia clematitis. Both A. apollinus and Z. polyxena used all four Aristolochia species, the former preferring Aristolochia rotunda and Aristolochia hirta, the latter Aristolochia rotunda and Aristolochia pallida. Zerynthia cerisy did not use the early-growing Aristolochia pallida while frequently using the late-growing Aristolochia clematitis. Further parameters affecting oviposition were biotope and canopy closure: early A. apollinus tolerated shady sites but late Z. cerisy avoided them. The simultaneous use of several host plants differing in phenology and habitat requirements, combined with rather high dispersal ability, arguably buffers the butterflies’ population dynamics against yearly variation in weather, while allowing efficient occupation of the diverse Mediterranean landscapes. The regional habitat diversity, created during millennia of human activity, is currently threatened by land abandonment, which may diminish the resource base for the studied butterflies.     

基于模拟有限差分的嵌入式离散裂缝数学模型

嵌入式离散裂缝模型划分网格时不需要考虑油藏内的裂缝形态,只需对基岩系统进行简单的网格剖分,可以大大降低网格划分的复杂度,从而能够提高计算效率.并且该模型可以将现有成熟的油藏数值模拟技术和离散裂缝网络模型有机地结合起来,能精细地模拟流体在裂缝性油藏中的流动.本文模型求解采用模拟有限差分方法,该方法基于单个网格的节点和面信息构造数值计算格式,理论上适用于任何复杂网格系统,且具有良好的局部守恒性,将其推广到嵌入式离散裂缝模型后,克服了该模型基于有限差分方法求解时不能有效处理全张量形式的渗透率以及不适用于复杂边界形状裂缝性油藏的局限性.最后通过实际算例验证了本文方法的正确性和优越性.     

Halacarid mites (Acari: Halacaridae) associated with a North Atlantic subtidal population of the kelp Laminaria ochroleuca

We characterised the mite fauna associated with a subtidal population of Laminaria ochroleuca in the Cantabrian Sea during a 4-year study. We found 2780 individuals belonging to 35 species. The mite assemblage comprised both north Atlantic and Mediterranean species, as usually reported from the Lusitanian region. The most abundant and diverse subfamily was Copidognathinae, followed by Halacarinae and Lohmannellinae. The greatest abundance of mites was detected on kelp holdfasts, not only strictly phytal mites were found but also interstitial mites or those associated with other macrofauna. Such a distribution could be explained by the high diversity and heterogeneity of microhabitats provided by holdfasts. Mite abundance fluctuated during the 4 years of the study. However, the lowest abundance was detected during the last year of sampling. During that year, the studied algal population suffered a severe decay leaving only degenerating holdfasts attached to the substrate, which could explain the decrease in mite numbers.     

Ten new species of the subgenus Steganina (Diptera: Drosophilidae: Stegana) from southern China

Ten new species of the subgenus Stegana (Steganina) are described from southern to south-western China: S. (S.) convena sp. nov., S. (S.) cylindrica sp. nov., S. (S.) eurystoma sp. nov., S. (S.) hamata sp. nov., S. (S.) hirticeps sp. nov., S. (S.) latigena sp. nov., S. (S.) planiceps sp. nov., S. (S.) rhomboica sp. nov., S. (S.) setivena sp. nov. and S. (S.) sphaerica sp. nov. They cannot be placed under any established species groups. http://www.zoobank.org/urn:lsid:zoobank.org:pub:D4B6C5A7-3700-4B0C-8355-E4564C2A7296     

掘进机新型液压油箱的设计与应用

液压油液的温升与污染是制约液压系统可靠性与液压元件寿命的关键。为了减小因油箱的设计缺陷而引起的油液污染速度快,温升高的问题,对EBZ230掘进机泵站闭式油箱进行改进设计。通过样机的应用与实验证明了这种新型的油箱系统能更有效地降低油液的污染速度与等级、更平稳更快速地冷却油液,对提高整机液压系统可靠性与稳定性有非常积极的意义。该油箱结构亦可应用于有着相似要求的液压设备中,具有较高的推广价值。     

东坪基岩气藏气水相对渗透率的确定方法

东坪基岩气藏储层岩性差异大,非均质性强.孔缝发育区岩石松散,无法钻取完整的岩芯,而致密带几乎不渗透,无法通过驱替实验获取相对渗透率曲线,这成为困扰气藏动态分析和开发指标计算的难题.基于水驱气藏物质平衡原理,建立了不依赖水侵量的储层含水饱和度计算方法,避免了水侵量计算方法中的不确定因素,提高了含水饱和度计算的准确性.建立...     

超声热疗中媒质特性对声聚焦的影响

以凹球面自聚焦超声换能器为例,用瑞利积分进行数值模拟计算,研究声衰减、声速、温度等参数对声聚焦的影响,并对不同生物组织中声聚焦的特点进行了比较.研究表明,不同的媒质的特性参数聚焦表现出不同的特点.声衰减系数增大,则焦斑向声源靠近且焦斑缩短;声速越大,则焦距越小,但焦域最大声压值升高,焦斑的面积增大;温度变化不大时,对声聚焦的影响不明显.     

线性区域数量与PLNN表达能力的相关性

使用分段线性激活函数的神经网络(PLNN)在机器学习中得到广泛应用.本文给出了一种PLNN模型表达能力的度量值——线性区域数量,并给出了线性区域的数学表示.分析了线性区域之间的关系并计算合并后的线性区域数量,同时给出一种基于Z曲线的线性区域数量的计算方法.针对一个任务实例进行分析,计算不同网络结构的线性区域数量及合并后...     

经济欠发达地区产业集群作用机理研究——以河南省为例

研究提出了经济欠发达地区产业集群作用机理,以较低的经济成本启动或推动当地工业化进程,并通过集群效应,加速资本积累,提升地区核心竞争力,安排更多的劳动力从传统农业转向现代工业生产领域,逐步完成社会结构由农业社会向工业社会的重大历史性转变.