国际空间站上阿尔法磁谱仪电子设备热系统的研究与设计

阿尔法磁谱仪是国际空间站上进行大型物理科学实验的仪器,包含6组精密探测仪和650个微电子处理器,主要目的是探测暗物质和反物质的存在.本文主要对阿尔法磁谱仪电子设备的热系统进行设计、模拟和分析,进行了热真空热平衡测试以及AMS在轨运行监控.对典型工况的模拟分析结果表明,电子设备的热系统能够确保所有电子设备在要求的温度范围内工作;在轨运行的启动曲线和长时间实时监测数据表明,AMS电子设备运行正常,AMS的热系统符合设计要求,能够维持电子设备在规定温度范围内工作.     

逃离“北上广深”背景下一线城市房价涟漪效应研究

本文基于逃离"北上广深"背景,研究了一线城市对二三线城市的房价涟漪效应,并从城市规模大小、距一线城市远近和涟漪效应高低三个方面,对比分析各因素对涟漪效应的影响.研究发现:1)逃离"北上广深"背景下,产业相似度、生活舒适性差距、交通便捷性、住房市场信息距离、社会文化距离、就业增长率、开放度和总储蓄均对涟漪效应表现出显著促进作用;2)二线城市各因素的影响程度均大于三线城市;3)随着与一线城市距离的增加,产业相似度、交通便捷性、就业增长率和开放度的影响呈递减趋势,生活舒适性差距呈递增趋势,住房市场信息距离和总储蓄基本与距离无关;4)随分位数提高,多数变量的影响程度增强,表现出"加速效应".     

Types of cladoceran species described by Sven Ekman in the Swedish Museum of Natural History,with redescription of Daphnia cavicervix Ekman, 1900 (Daphniidae,Anomopoda, Cladocera)

In the course of our examination of samples of Cladocera from South America and subantarctic islands in the collection of the Swedish Museum of Natural History, Stockholm, we found some type material of Sven Ekman, unrecognized earlier, as well as other samples described in his publications (Ekman 1900 Ekman, S. 1900. Cladoceren aus Patagonien, gesammelt von der schwedischen Expedition nach Patagonien 1899.. Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere, 14: 62–84.  [Google Scholar], 1905 Ekman, S. 1905. Cladoceren und Copepoden aus antarktischen und subantarktishen Binnengewässern.. Wissendchaftliche Ergebnisse der Schwedischen Südpolar‐Expedition 1901–1903, Zoologie, 5: 1–40.  [Google Scholar]). A single specimen of Pleuroxus scopuliferus Ekman, 1900 Ekman, S. 1900. Cladoceren aus Patagonien, gesammelt von der schwedischen Expedition nach Patagonien 1899.. Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere, 14: 62–84.  [Google Scholar], apparently seen by its author, is re‐deposited as the lectotype, while the neotype of this taxon earlier selected by Frey (1993 Frey, D. G. 1993. Species of Pleuroxus (Anomopoda, Chydoridae) from the subantarctic islands and southernmost South America: a partial unravelling of the Pleuroxus aduncus problem.. Hydrobiologia, 262: 145–188.  [Google Scholar]) must be rejected according to ICZN (2000 ICZN. 2000. International code of zoological nomenclature , 4, 306London: International Trust for Zoological Nomenclature.  [Google Scholar]). Daphnia cavicervix Ekman, 1900 Ekman, S. 1900. Cladoceren aus Patagonien, gesammelt von der schwedischen Expedition nach Patagonien 1899.. Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere, 14: 62–84.  [Google Scholar] is redescribed based on numerous parthenogenetic, ephippial females and males, and lectotype and paralectotypes are selected. Some recent problems of systematics of Daphnia in South America are discussed.     

Microstructures and nanostructures of high Andean Penaincisalia lycaenid butterfly scales (Lepidoptera: Lycaenidae): descriptions and interpretations

The scales of one high Andean eumaeine lycaenid butterfly species with pale dorsal coloration and four species with vivid dorsal colour were investigated using field emission scanning electron microscopy. The micro‐ and nanostructures are illustrated, described, measured, and interpreted. The vivid colours in the species are caused by a pepper‐pot nanostructure of Urania‐type scales. This nanostructure is a three‐dimensional lattice within the body of the individual scale. The scales of the non‐vivid orange species are lacking this nanostructure and the surfaces of their scales show high microstructure irregularities. This absence of vivid colour may be correlated with thermal regulation. The irregularity of the scale microstructures suggests a heavy environmental pressure on the populations sampled. Previously unknown structural variations of Urania‐type scales are also described. The existence of closed scale microcell structures, explained as an apomorphic character in the tribe Eumaeini, most probably evolved independently several times. It is hypothesized that scale micro‐ and nanostructure modifications develop syntopically within a population, which in turn can lead to rapid diversification.     

Revision of ‘Horatia’ snails (Mollusca: Gastropoda: Hydrobiidae sensu lato) from South Caucasus with description of two new genera

Four nominal species of the genus Horatia Bourguignat, 1887 were described by Russian authors from Caucasian caves (H. borutzkii Shadin, 1932, H. birsteini Starobogatov, 1962, H. ljovushkini Starobogatov, 1962 and H. sokolovi Starobogatov, 1962). Hitherto all the species were known from type series (presented by empty shells) only. Examination of newly obtained samples from the caves of South Caucasus has shown that the four species actually do not belong to the genus Horatia due to obvious differences in the morphology of the copulatory organs between H. klecakiana Bourguignat, 1887 (the type species of this genus) and the Caucasian snails. Moreover, statistical analysis of conchological variation has revealed that the species H. birsteini, H. ljovushkini, and H. sokolovi are conspecific. Two genera are described: Pontohoratia (includes P. birsteini and P. smyri sp. nov.) and Motsametia (with the single species M. borutzkii comb. nov.). The two genera can be distinguished on the basis of the structure of their copulatory organs. The distribution and ecology of the Caucasian Horatia-like mollusks are briefly outlined.

http://zoobank.org/urn:lsid:zoobank.org:pub:4EDFB2AE-CB1D-4113-8CC7-3A1BBB46D838     

北京市公园绿地植物多样性研究

保护城市的生物多样性至关重要。城市公园是城市园林绿地系统的主体,也是城市里植物多样性最集中的地方,研究城市公园植物多样性可为城市生物多样性保护提供基础数据。通过北京市主要公园绿地植物的调查,分析了城市公园绿地植物的种类构成,计算并论述了公园绿地的生物多样性特征,以期能够为北京生态城市建设提供科学依据。调查发现北京城市公园绿地植物物种较为丰富,共有90科,251属,393种;植物种类构成以乡土种为主体,引进种也较为丰富。其中北京本地种281种,占总数的71．50％,国内引进种62种,占总数的15．78％,国外引进种50种,占总数的12．72％;公园绿地植物物种丰富度以草本植物最高,其次是灌木植物,乔木植物总体稍低于灌木;公园绿地植物物种多样性总体较高。     

基于随机分析的公交站点乘客等车时间

分析了公交站点乘客等车过程的随机特性,在公共汽车和秉客均随机到站的条件下,确定了描述乘客在公交站点等车过程中关键状态的一系列随机变量,用图示的方法予以说明.从两个角度研究了公交站点乘客的累积等车时间,并根据随机过程理论推导出其均值的计算公式.结果表明有效控制顺次相邻两公共汽车离开公交站点的间隔时间并尽可能减少其波动可以缩短公交站点乘客的累积等车时间.     

铁路起重机新型支腿结构设计与研究

介绍了一种新型的起重机支腿结构,该结构采用焊接方式,具有重量轻,承载能力高,外观质量好,制造工艺简单,安装方便等优点.     

北京旧城斜街形成原因考

主要通过对相关文献，地图，碑刻资料的分析，结合前人的成果，对北京旧城斜街的形成提出三点看法：1）因湖泊面积缩小，形状变化，原来的湖岸变成斜街；2）街道本身即在是河道上，或沿河道沟渠延伸，形成斜街。3）在关厢地区，人们为进出城方便，需要走最短距离，形成斜街。     

通过精准测量结合大机作业解决线路长波不平顺问题

针对时速160km/h的太中银线的实际情况,提出了一种通过精准测量结合大机作业彻底解决影响高速列车运行安全及舒适度的长波高低不平顺的方法,提出远期建立高精度的轨道控制桩系统的建议,以便于现场维修与大机作业,提高作业质量与效率。