拟刺葵（苦戈维尔叶）亚属Phoenicopsis（Culgoweria）在内蒙古鄂尔多斯盆地中侏罗统的发现     

李涛  李云峰  那玉玲  黄薇  孙春林 《世界地质(英文版)》2014,(3)

大量茨康类压型化石在鄂尔多斯盆地中侏罗世含煤地层延安组中被发现。本文根据叶外部形态和表皮构造特征,首次发现拟刺葵属的苦戈维尔叶亚属Phoenicopsis （ Culgoweria）,并建立了鄂尔多斯拟刺葵（苦戈维尔叶）（新种） Phoenicopsis （ Culgowaria） ordosensis sp.nov。新种代表了该亚属在我国中侏罗世的第一个化石记录,为研究其地质、地理分布提供了新的证据,也为研究该类植物在欧亚大陆中侏罗世的多样性增添了新内容。  相似文献   

穿越南沙礼乐滩的海底地震仪广角地震试验   总被引：16，自引：9，他引：7       下载免费PDF全文

阮爱国  牛雄伟  丘学林  李家彪  吴振利  赵明辉  卫小冬 《地球物理学报》2011,54(12):3139-3149

本文对穿越礼乐滩东北部向西北方向延伸进入中央海盆长369 km的广角地震剖面OBS973-2进行了反演研究,以期了解南海南部陆缘的地壳结构,同时探讨南、北陆缘的共轭问题.结果表明OBS973-2剖面的速度模型中三个沉积层的速度分别为1.8～2.0 km/s、2.0～2.7 km/s和3.5～4.0 km/s;沿剖面沉积...  相似文献   

小井眼侧钻水平井钻完井工艺在QHD32—6油田的应用     

金鑫  张飞  王占领  苏建  李艳飞  白维昊  那宇 《海洋地质译丛》2011,(3):89-92

由于海洋石油开发的特殊性,每个采油平台的槽口数量有限,而新建平台或者外挂槽口成本太高,因此利用低效井和关停井的槽口进行套管内开窗侧钻成为一种很好的选择。QHD32—6F平台部分生产井为中177．8mm生产套管,利用修井机在Ф177．8mm生产套管内开窗侧钻Ф152．4mm小井眼,直接着陆钻水平段,裸眼段最长达1120m,平均长1032m。该工艺技术可操作性较强,工期短,成本低,为延长老油田寿命,维持老油田经济开发指明了方向。  相似文献   

弹性矢量波成像域联合层析反演          下载免费PDF全文

秦宁  李振春  张凯  杨晓东 《地球物理学报》2013,56(9):3109-3117

在地震弹性矢量波场框架下,推导了多波联合层析速度反演方程以及走时残差与角道集剩余曲率的转换关系式,提出了一种利用成像域角道集更新P波、S波速度的走时层析反演方法.其实现过程可以概括为:将弹性波多分量数据作为输入,基于高斯束实现矢量波场成像并提取角道集,利用层析反演方程求解慢度更新量,最终获得多波联合反演结果.模型试算和实际资料处理验证了该方法的反演效果,能够为弹性矢量波联合深度偏移提供高质量的叠前速度场.  相似文献   

南麂列岛中华蛸(Octopus sinensis)形态与遗传多样性分析     

李嘉华  陈舜  陈万东  谢尚微  倪孝品  郑小东 《海洋与湖沼》2022,53(2):486-495

2020年6~12月在南麂列岛采捕一种中大型章鱼44只,描述了形态特征,采用多元分析方法分析了形态多样性,并比较了与真蛸的差异,利用线粒体细胞色素氧化酶亚基I(COI)基因序列构建了系统发育树,并计算了Kimura-2-Parameter(K2P)遗传距离。结果表明,此种章鱼形态特征与中华蛸基本一致,而与真蛸存在显著的形态差异:其第二、三对腕的扩大吸盘位于第12~15个吸盘之间,而真蛸则位于第15~19个吸盘之间;茎化腕吸盘数少于真蛸;舌叶指数小于真蛸。主成分分析与判别分析能将真蛸群体显著区分开,判别准确率为100%,而其余四个群体(南麂列岛与三个中华蛸群体)间存在重叠;聚类分析表明南麂列岛群体与中华蛸更近,二者均与真蛸存在较大距离。在遗传多样性分析中,南麂列岛群体单倍型4个,单倍型多样性水平为0.320±0.121,多态位点6个,核苷酸多样性指数为0.001 11;系统发育树表明,该群体与中华蛸亲缘关系最近,K2P遗传距离0.14%,而与真蛸复合体其他类型为2.96%~12.11%。因此,从形态和分子水平鉴定南麂列岛章鱼为中华蛸。  相似文献   

Scientific attributes and expression methods of geographical boundary     

TANG Guoan  LI Jilong  XIONG Liyang  NA Jiaming 《地理学报(英文版)》2022,32(6):1119-1135

A scientific delineation of geographical boundaries reflects the cognitive level of scientific abstraction and systematic analysis of the spatial variation of geographical objects and is a basic scientific issue of geography. From the perspective of earth system science, this study first explicates the core issues (e.g., basic concepts, scientific contents, and basic properties) of geographical boundaries. Based on the principles of scientificity and systematicness, we then classify geographical boundaries in terms of intrinsic mechanisms, extrinsic appearance and scientific attributes. Furthermore, this paper analyzes the mathematical connotation and representation methods of geographical boundaries, discusses the characteristics of and differences between traditional and modern methods for geographical boundary delineation. Finally, we present a framework for a “geographical boundary model” with an integration of qualitative, quantitative, and positioning methods. Focusing on geographical boundary (a basic theoretical problem in geography), this study engaged in concept definition and method analysis, with the findings enriching the theory and methodology of geographical information science.  相似文献   

Lithium abundances of 21 solar-type stars near the Sun     

Li-Feng Xing  Shuang-Yi Zhao  Xiao-Dong Zhang 《New Astronomy》2012,17(5):537-541

We present high-resolution spectroscopic observations for a sample of 21 young, solar-type stars near the Sun recently discovered in the X-ray wavelength range during the ROSAT all-sky survey. Based on these observations, we derive the lithium (Li) abundances of these 21 sample stars. Using the lithium abundances and the X-ray luminosity, we investigated the relationship between the Li abundances and the X-ray activity. We found a clear correlation between the lithium abundances and the X-ray luminosity: as the X-ray luminosity became stronger, the lithium abundance decreases in our sample stars. Our sample results provide further evidence that a correlation appears to exist between Li abundances, X-ray activity and age for a large number of solar-type stars. The results also confirm the presence of very active young stars close to the Sun, in agreement with recent findings from UV and X-ray surveys.  相似文献   

福建漳江口红树林湿地生态系统服务功能价值评价   总被引：1，自引：0，他引：1  

陈欢欢  刘晓东  林伟山  孙晓娟  张阳武 《湿地科学与管理》2013,(2):30-34

根据漳江口湿地生态系统的特点,将保护区生态系统服务功能总价值划分为直接使用价值(包括直接实物价值和直接服务价值)、间接使用价值和非使用价值。以2010年为基准年,评价了研究地生态系统服务功能价值,得出保护区生态系统服务功能总价值为21472.25万元,其中直接使用价值为6910.69万元,间接使用价值为14509.56万元,非使用价值为52.00万元。漳江口红树林湿地的间接使用价值远高于直接使用价值。漳江口红树林湿地积累营养物质和生物多样性保护的价值约占总价值60%,说明漳江口红树林保护工作富有成效,维持了红树林生态系统完整性,使生态系统具有较高生产力,对生物多样性维持具有重要意义。  相似文献   

Sap flow characteristics of four typical species in desert shelter forest and their responses to environmental factors   总被引：2，自引：1，他引：1  

Jian-Xin Ma  Ya-Ning Chen  Wei-Hong Li  Xiang Huang  Cheng-Gang Zhu  Xiao-Dong Ma 《Environmental Earth Sciences》2012,67(1):151-160

Sap flows of four typical species, Populus. russkii Jabl., Populus euphratica Olive., Ulmus pumila L., and Elaeagnus angustifolia L., of artificial shelter forest in a desert area were monitored in all-weather conditions using SF300 Sap flow Meter based on the theory of thermal compensation. Meanwhile, air temperature (T _a), leaf temperature (T _l), soil temperature (T _s), relative humidity (RH), and wind velocity (V _w) were simultaneously recorded by an automatic weather station. The results indicate that (1) the diurnal processes of stem sap flows of P. russkii Jabl., P. euphratica Olive., and U. pumila L., but not E. angustifolia L., show an obvious circadian rhythm. Significant differences of stem sap flow rates were found among species, but not genus. The average sap flow rate of P. russkii Jabl. is 13.8-fold of that of E. angustifolia L. The order of sap flux density (SFD) from the largest to the smallest is P. russkii Jabl., P. euphratica Olive, U. pumila L. and E. angustifolia L.; (2) compared with 373?mm, 747?mm irrigation can induce microenvironmental changes that result in the suppression of photosynthesis and transpiration and the decline of stem sap flow rates of the above four species, indicating 373?mm irrigation meets the growth needs of the above species during experiment; (3) sap flow rates are different at different stem positions: the flow rates of P. russkii Jabl., U. pumila L. and E. angustifolia L., but not P. euphratica Olive, decline gradually from cambium to pith; (4) the correlation analysis indicates that stem sap flow is negatively correlated with RH and T _s and positively correlated with T _a, T _l and saturation vapor pressure deficit (VPD). The sap flow rate of P. russkii Jabl. is significantly affected by V _w due to its large size and height. In addition, a model was established by stepwise regression analysis to estimate the relationship between the environmental factors and stem sap flows of the above four typical species of shelter forest in the desert area.  相似文献   

内蒙古中部中更新统离石黄土特征及第四纪气候变化   总被引：1，自引：0，他引：1  

李满环  那丹妮  徐承泽 《吉林地质》2012,(4):23-27

内蒙古中部包头市—呼和浩特市一带由两种不同地貌单位组成,北部大青山山脉、南部为河套平原。区内第四系发育齐全,沉积厚度巨大。离石黄土的岩性主要为一套黄褐色、深黄褐色和棕褐色的粘黄土为主,夹有砂黄土、钙结黄土、钙质结核黄土层和古土壤层。热释光年龄在(37.19±2.83)×104aB.P.～(15.72±1.21)×104aB.P.。第四纪沉积物特征反应了环境和气候变化特征,在中更新统主要以干冷气候为主,期间出现了3个潮时。晚更新世早期为末次间冰期(12.8～7.00万年)气候,气候温暖湿润。本测区自6.8万年至0.95万年为湖相和风沙堆积,表明气候进入干冷气候期,为末次冰期(7.4～1万年)气候。  相似文献