A new Osmylidae (Insecta,Neuroptera) from the Lower Cretaceous Crato Formation in Brazil     

《Cretaceous Research》2015

Cratosmylus magnificus gen. et sp. nov., type genus and species of the new osmylid subfamily Cratosmylinae, is described from the Lower Cretaceous of the Crato Formation, Brazil. The relationships of this taxon remain uncertain within the Osmylidae, mainly due to the lack of phylogeny of the whole family. Nevertheless, it shares with the Mesozoic subfamily Saucrosmylinae the Rs curved and bent anteriorly distally, even in a more pronounced state, i.e. Rs touching R1 in its distal part.  相似文献   

基于非线性规划原理绘制钻孔柱状图方法研究     

徐晓斌  何宝石  王清 《世界地质》2015,34(4):1149-1154

针对现有钻孔柱状图绘制中描述文字空间分布存在的问题,采用弹性理论-非线性原理对柱状图描述文字位置进行规划,合理分配各岩层描述单元空间,形成柱状图的初步分布;计算出各个地层的工程地质描述文字在柱状图图纸中最优位置的高度坐标xi;利用Auto CAD软件图形绘制环境,实现全程自动绘制钻孔柱状图的新方法。该方法高效且专业性强,图件规范、整齐、文字分布合理、格式美观,无需对图件进行后期的手动处理,免去了人工处理过程,节约了大量的人力成本。  相似文献   

大瑞铁路高黎贡山越岭段主要工程地质问题与地质选线   总被引：2，自引：1，他引：1  

李光伟  杜宇本  蒋良文  郭长宝  沈维  刘筱怡 《地质力学学报》2015,21(1):73-86

在野外地质调查、钻探、地应力测量和室内测试分析的基础上,对大瑞铁路高黎贡山越岭段规划设计中可能遇到的高地温、高地应力、活动断裂断错、岩爆、涌水突泥、软岩大变形和边坡稳定性等主要工程地质问题进行了论述,认为高地温和热害是制约高黎贡山深埋隧道段建设的关键因素。根据地热钻探、测试资料分析,该区的地热分布受断裂构造控制明显,黄草坝断裂具有阻水隔热的工程地质特性。对比分析认为,C12K方案(34.5 km越岭长隧道方案)位于黄草坝阻水隔热断层之南,通道内相对低温,且在隧道口处避让了古滑坡等不利工程地质问题,在众多比选方案中工程地质条件较好。调查研究结果对大瑞铁路全线贯通具有重要意义。  相似文献   

桂林洞穴滴水与现代碳酸钙δ18O记录的环境意义--以桂林七星岩NO.15支洞为例     

张美良  朱晓燕  吴夏  张碧云  潘谋成 《沉积学报》2015,33(4):697-705

现代洞穴动态监测的一个先决条件就是为洞穴碳酸盐(CaCO₃)沉积物-石笋的各种替代指标的解译提供可靠的依据,充分利用现代碳酸盐(CaCO₃)沉积物的各种替代指标,并与现代器测气象资料进行相互对比、并用以校正,是精确或定量解释石笋气候替代指标的关键.
经对桂林七星岩15号支洞的5个滴水点进行了长达四个水文年(2008~2011年)的大气降水、洞穴滴水、现代碳酸盐沉积物的动态监测和研究,并探讨了洞穴滴水和现代碳酸盐(CaCO₃)的δ18O与降水δ18O的相关关系.研究表明,洞穴滴水和现代碳酸盐(CaCO₃)的年平均δ18O值非常接近降水的δ18O平均值,并具有与地表降水δ18O相同的变化趋势,反映了洞穴滴水和现代碳酸盐(CaCO₃)的δ18O主要来自大气降水的δ18O,即明显受控于降水的δ18O.在4个水文年中,现代洞穴次生化学碳酸盐(CaCO₃)沉积物的δ18O值与滴水的δ18O值记录的年内(或年际)变化或多年的变化趋势基本相同,表现出明显的四高峰(δ18O低值区)四低谷(δ18O高值区)的波动变化特征,具有明显的年际、季节性变化规律,显示具有雨热同季的特点.研究结果表明洞穴滴水和洞穴现代碳酸盐(CaCO₃)沉积物的δ18O可以记录当地或洞穴上方的气候变化信号,即现代碳酸盐(CaCO₃)沉积物的δ18O主要作为夏季风强度或降雨量的替代指标.  相似文献   

西藏大冈底斯北部金属矿床成矿系列研究   总被引：1，自引：0，他引：1  

罗梅  潘凤雏  李巨初  徐志忠  邓午忠  李关清  刘丽君 《地质学报》2015,89(4):715-730

依据近年西藏自治区矿产资源大调查的资料与西藏自治区矿产资源潜力评价研究获得的系统、详细的矿产资源资料,编写论述了西藏大冈底斯北部(包括班公湖-怒江成矿带、北冈底斯成矿带、中冈底斯成矿带三个成矿带)的矿产地质特征及成矿分布规律与成矿系列。班公湖-怒江成矿带包括燕山早期(洋盆形成时期,如东巧铬矿)及燕山中晚期(陆内俯冲挤压时期,如屋索拉金矿)岩浆作用有关矿床成矿系列和那曲-洛隆盆地与喜马拉雅期流体作用有关(如纳多弄铅矿)矿床成矿系列;北冈底斯成矿带矿床主要分布在申扎—嘉黎一线的北部地区(亦称冈底斯北矿带),包括玉古拉镍矿(燕山早期,岩浆岩型)、舍索铜矿(燕山中晚期,矽卡岩型为主)、尤卡朗-昂张铅矿(燕山中晚期,热液型为主)、俄龙呷砷矿(燕山晚期—喜马拉雅早期,流体-改造型为主)四个地区不同类型矿床成矿系列;中冈底斯成矿带包括近东西向两个成矿亚带,北边为革吉-雄巴-文部成矿亚带燕山中晚期(如尕尔铜金矿)及狮泉河-申扎弧-盆系演化期岩浆热液成矿作用的矿床成矿系列,南边为朗久-塔诺错-纳木错成矿亚带喜马拉雅中晚期(如甲岗钨钼铋矿)岩浆热液成矿作用的矿床成矿系列。  相似文献   

黄山不同高度雨滴谱的演变特征   总被引：1，自引：0，他引：1       下载免费PDF全文

陈聪  银燕  陈宝君 《大气科学学报》2015,38(3):388-395

选取2011年6月黄山地区一次降水过程,利用测得的雨滴谱资料对不同高度上降水微物理量及雨滴谱分布特征进行分析,并讨论其中的差异。结果表明:此次降水较强,各直径微物理量在山腰最大、山底次之、山顶最小;山腰的雨强最大,而山顶数浓度最大。在雨滴谱分布中,小于1mm的雨滴数密度是山顶大于山腰大于山底,这与小雨滴的蒸发和碰并有关;大于1.5 mm的雨滴数密度则是山腰大于山顶和山底,这可能与地形抬升使得云系加强有关。由各微物理量的时间序列可将降水过程分为两个阶段,第一阶段各微物理量值明显大于第二阶段,其中第一阶段的降水量约为第二阶段的3倍。雨强与雷达反射率、数浓度、最大直径近似成幂函数关系,其中雨强与雷达反射率相关性最好。  相似文献   

Extensive genetic divergence among Diptychus maculatus populations in northwest China     

孟玮  杨天燕  海萨  马燕武  蔡林钢  马徐发  高天翔  郭焱 《中国海洋湖沼学报》2015,33(3):577-584

D. maculates is a kind of specialized Schizothoracinae fish has been locally listed as a protected animal in Xinjiang Province,China. Ili River located in north of Tianshan Mountain and Tarim River located in north of Qinghai-Tibetan Plateau were two main distribution areas of this fish. To investigate the genetic diversity and genetic structure of D. maculates,four populations from Tarim River system and two populations from Ili River system were collected in this study. A 570-bp sequence of the control region was obtained for 105 specimens. Twenty-four haplotypes were detected from six populations,only Kunes River population and Kashi River population shared haplotypes with each other. For all the populations examined,the haplotype diversity(h) was 0.904 8±0.012 6,nucleotide diversity(π) was 0.027 9±0.013 9,and the average number of pairwise nucleotide differences(k) was 15.878 3±7.139 1. The analysis of molecular variance(AMOVA) showed that 86.31% of the total genetic variation was apportioned among populations,and the variation within sampled populations was 13.69%. Genetic differences among sampled populations were highly significant. F st statistical test indicated that all populations were significantly divergent from each other(P 0.01). The largest F st value was between Yurungkash River population and Muzat River population,while the smallest F st value was between Kunes River population and Kashi River population. NJ phylogenetic tree of D-loop haplotypes revealed two main clades. The neutrality test and mismatch distribution analysis suggested that the fish had went through a recent population expansion. The uplift of Tianshan Mountain and movement of Qinghai-Tibetan Plateau might contribute to the wide genetic divergence of D. maculates in northwest China.  相似文献   

洞庭青鲫(Carassius auratus var.Dongtingking)与三个鲫品系群体遗传多样性的ISSR分析   总被引：2，自引：1，他引：1  

刘良国  杨品红  谢春华  王晓艳  徐黎明 《海洋与湖沼》2015,46(2):426-431

采用ISSR分子标记技术,对洞庭青鲫(Carassius auratus var.Dongtingking)、野生二倍体和三倍体鲫(C.auratus)、彭泽鲫(C.auratus var.Pengze)4个鲫品系群体共120个个体的遗传多样性进行分析。9个ISSR引物在四个鲫品系群体中共获得1637个扩增位点,其中多态位点1572个,多态位点比例为96.03%。4个鲫品系群体内的多态位点比例分别为46.14%、65.40%、73.76%和51.94%,遗传距离分别为0.0905、0.1186、0.1351和0.1056。在4个鲫品系群体之间,洞庭青鲫与彭泽鲫的遗传距离最小(0.1191),二倍体鲫和三倍体鲫的遗传距离次之(0.1336),而洞庭青鲫、彭泽鲫与二倍体鲫的遗传距离(分别为0.1377、0.1367)略小于它们与三倍体鲫的遗传距离(均为0.1378)。UPGMA聚类结果为洞庭青鲫与彭泽鲫聚成一个分支,二倍体鲫与三倍体鲫聚成另一个分支。结果表明,洞庭青鲫、彭泽鲫等养殖群体内的遗传多样性明显低于野生鲫群体;四个鲫品系中,洞庭青鲫与彭泽鲫的亲缘关系较近,二倍体鲫与三倍体鲫的亲缘关系较近,推测洞庭青鲫、彭泽鲫、三倍体鲫均起源于二倍体鲫。二倍体洞庭青鲫和二倍体野生鲫资源的保护必须引起重视。  相似文献   

High connectivity and directional gene flow in European Atlantic and Mediterranean populations of Ciona intestinalis sp. A          下载免费PDF全文

Ornella Affinito  Nikos Andreakis  Luigi Caputi  Rita Marino  Raimondo Pannone  Paolo Sordino  Gabriele Procaccini 《Marine Ecology》2015,36(4):1230-1243

Understanding the factors that cause population divergence has long been of interest to marine biologists in their attempts to interpret the effect of human‐mediated vectors. Broadcast‐spawning species with limited dispersal capability are excellent candidates to measure the present‐day patterns of genetic diversity. The tunicate Ciona intestinalis (Ascidiacea) is comprised of a complex of morphologically cryptic species that form vigorous aggregates in eutrophic habitats (harbors, gulfs and lagoons) where they can compete with the epibenthic community and cause biofouling problems. This study investigated biogeographic variability and migration patterns of C. intestinalis sp. A along Northeast Atlantic and Mediterranean coasts using microsatellite markers. Data presented here on 371 specimens collected from 17 populations reveal high genetic polymorphism, but with a deficit of heterozygote deficiency. Absence of evidence for isolation by distance suggests that the genetic patterns do not reflect the geographic distribution of sampled populations. Substantial gene flow and artificial potential for dispersal boost high levels of within‐population genetic variability and prevent genetic differentiation within and between seas. A predominant eastward migration pattern was revealed by the data set, with very limited opportunity for C. intestinalis sp. A to travel westward. This directional movement indicates that other properties (e.g. habitat quality, genetic traits, mating system, life cycle) may cause adaptive divergence at a large biogeographic scale.  相似文献   

红树植物无瓣海桑果实的化学成分研究   总被引：1，自引：0，他引：1       下载免费PDF全文

曹雷雷  田海妍  王友绍  周雪峰  江仁望  刘永宏 《热带海洋学报》2015,34(1):77-82

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