Cenozoic giant coal-bearing basin belt discovered in China’s sea area     

Gongcheng Zhang  Ying Chen  Dongdong Wang  Zengxue Li 《海洋学报(英文版)》2023,42(3):101-112

Sea area is an important area of oil and gas exploration in China. It has been found that China’s sea area mainly consists of coal type oil and gas, and the exploration of coal-bearing series source rocks has become an important part of oil and gas exploration there. Through years of comprehensive geological research in China’s sea area, it has been revealed that it has undergone multiple occurrences of tectonic opening and closing movements in varying degrees in the Paleogene, forming 26 Cenozoic sedimentary basins of various types, such as active continental margin, passive continental margin, transitional continental margin and drift rift basins. In the present study, it is observed for the first time that coal type source rocks are mainly developed in 14 continental margin basins in China’s sea area, revealing that a very large C-shaped coal-bearing basin group developed there in the Cenozoic. Next, based on the coupling analysis of paleoclimate, paleobotany, paleogeography and paleostructure, it is observed that there are five coal-forming periods in China’s sea area, namely the Paleocene, Eocene, early Oligocene, late Oligocene and Miocene-Pliocene, and the coal-forming age is gradually new from north to south. It is also found that the coal seams in the sea area are mainly developed in three coal-forming environments in Cenozoic, namely delta, fan delta and tidal flat-lagoon. The coal seams developed in different environments are characterized by thin thickness, many layers and poor stability. However, the coal-bearing series source rocks in China’s sea area have a wide distribution range, very high thickness and large amount, thus forming a material basis for the formation of rich coal type oil and gas.  相似文献   

湖泊观测中的自动水下潜水器     

B. A. A. P. Balasuriy  浦环 《湖泊科学》1998,10(S1):591-597

This paper proposed the use of Autonomous Underwater Vehicles (AUVs) for lake observation. The performance of the proposed system is demonstrated at the lake Biwa in Japan using the test-bed AUV the "Twin-Burger 2" available at the University of Tokyo. The proposed AUV system is capable of moving autonomously to predetermined locations carrying different kinds of sensing equipment for lake survey and sensors for navigation. In this system, the predetermined path of the AUV is marked by laying an underwater cable. At the lake Biwa the Twin-Burger 2 successfully followed the cable while collecting information on the environment. In situations where the cable was lost from the image a search algorithm was activated and if not recovered the vehicle will come to the surface.  相似文献   

中山站地区大气边界层结构和湍流通量的输送特征   总被引：1，自引：0，他引：1       下载免费PDF全文

曲绍厚  高登义 《极地研究》1996,8(4):4-13

本文根据作者随中国第１１次南极考察队（１９９４－１９９６年）赴中山站夏考期间，使用ＴＭＴ（系留式气象塔）观测系统，在中山站、冰盖和海冰等三个点上观测到的气温、湿度、风速、风向和气压等大气要素的廓线资料，利用相似理论的通量－廓线关系，给出这三个观测点上的动量通量、曳力系数和感热通量，在近中性条件下，中山站粗糙度高度为２．９ｃｍ，冰盖与海冰点二者粗糙度高度差不多，分别为２．８×１０－２ｃｍ和３．６×１０－２ｃｍ，曳力系数则分别为５．０６×１０－３、１．３４×１０－３和１．４１×１０－３。结果表明，即使在中山站地区这样一个尺度范围内，由于下垫面的热力学特性、地形、地貌、地势和地理位置等的差异，无论是大气边界层结构还是湍流通量等的输送特性都有明显的差别，因此南极地区的大气边界层结构和冰（雪）－气交换特征都是比较复杂的，具有很强的局地性  相似文献   

泉州湾桐花树和老鼠簕根际土壤细菌和真菌群落特征比较          下载免费PDF全文

郑智胜  黄卫红  陈小尘  黄兆斌  薛喜枚  陈锦江  张秋芳 《应用海洋学学报》2023,42(4):686-697

红树植物根际土壤微生物对近海生物地球化学循环及其生物多样性等起着重要作用,受地上部和土壤性质影响,两种不同药用红树植物桐花树（Aegiceras corniculatum）和老鼠簕（Acanthus ilicifolius）根际土壤微生物群落组成可能存在独特性。本研究分别以细菌 16S rRNA基因和真菌ITS 基因为分子标记,采用高通量测序技术分析比较了桐花树和老鼠簕根际土壤微生物多样性特征及其与土壤理化性质之间的关系。结果表明：①老鼠簕根际土壤细菌和真菌多样性与丰富度均显著高于桐花树,且两者之间的细菌和真菌组成皆存在明显差异（P<0.05）;②两者根际土壤细菌和真菌门和属的优势（大于1%）物种组成皆相似;在门水平,桐花树根际土壤主要优势物种变形菌门（Proteobacteria）和未分类门（unclassified_k_Fungi）的相对丰度显著高于老鼠簕,而拟杆菌门（Bacteroidota）、脱硫杆菌门（Desulfobacterota）、子囊菌门（Ascomycota）和担子菌门（Basidiomycota）则相反;在属水平,桐花树的主要优势物种硝化螺菌属（Nitrospira）和Denitromonas属的相对丰度显著高于老鼠簕,而枝孢菌属（Cladosporium）和囊状担子菌属（Cystofilobasidium）则相反;③桐花树根际土壤pH、总碳和总酚含量皆显著高于老鼠簕,pH和总酚显著影响细菌群落组成,而总碳和总硫则显著影响真菌群落组成;此外,pH、总碳和总氮是影响细菌物种的主要因素,而总酚、pH和总碳是影响真菌物种的主要因素。本研究揭示了桐花树和老鼠簕根际土壤细菌和真菌多样性存在明显差异并与土壤理化性质密切相关,可为今后从不同红树物种所具备的独特功能根际微生物菌群来开发相关资源及保护近海的生态环境提供新的视角。  相似文献   

Sand wave migration near the southeastern corner of Martha's Vineyard,Massachusetts, USA     

《国际泥沙研究》2023,38(5):629-642

Sand waves of approximately 2 m in height were observed to migrate nearly 40 m with counterclockwise rotation between two bathymetric surveys performed three months apart near the southeastern corner of Martha's Vineyard, Massachusetts. The region is characterized by strong tidal currents, intermittent energetic surface wave events, and shallow water with local depth ranging from 2 to 7 m. This study uses the process-based model, Delft3D, with a three-dimensional approach to examine the sand wave dynamics by incorporating surface waves, winds, currents, and bathymetric observations. The model successfully simulates sand wave migration in comparisons to observations. Model sensitivity analyses show that the sand wave migration reduces by 65% with the absence of the surface waves. The modeled sand wave migration speed is correlated with the tidal current Shields parameter, and sharp increases in migration speed occur when the wave-driven Shields parameter increases in response to energetic surface wave events. The combined effect of tides, surface waves, and bathymetry is the origin of the rotational aspect of the sand wave, using the Shields parameter as an indicator of tidal currents and surface wave influence on sand wave dynamics.  相似文献   

Ephemrides of visual binaries in universal variables     

M.A. Sharaf  M.S. Abo‐Elazm  M.I. Nouh 《Astronomische Nachrichten》2000,321(1):59-64

In this paper, universal formulations of the two‐body problem are established for ephemerides of visual binary systems, whatever the type of their orbits may be. A computational algorithm is also given and applied to the binaries ADS 9159, ADS 2959 and ADS 11632 as typical examples of elliptic, parabolic and hyperbolic binaries, respectively.  相似文献   

Products and Kinetics of the OH‐radical‐induced Dealkylation of Atrazine     

A. Tauber  C. von Sonntag 《洁净——土壤、空气、水》2000,28(1):15-23

Hydroxyl radicals, generated radiolytically in N₂O/O₂‐saturated solutions, yield in their reaction with atrazine equal amounts of deethylatrazine and acetaldehyde (40% of OH radical yield) and deisopropylatrazine and acetone (16%), respectively. The precursors of deethylatrazine and acetaldehyde is their Schiff base which hydrolyzes slowly (OH^–‐catalyzed: k = 5.2 dm³ mol^–1 s^–1). The hydrolysis of the Schiff base of deisopropylatrazine and acetone is too fast to be detected. In a pulse radiolysis experiment, the intermediate formed upon OH‐radical attack (k = 3·10⁹ dm³ mol^–1 s^–1) has a strong absorption at 440 nm. It decays in the presence of oxygen (k = 1.3·10⁹ dm³ mol^–1 s^–1), and upon deprotonation [pK_a(peroxyl radicals) ≈ 10.5] the peroxyl radicals thus‐formed eliminate superoxide radicals (k = 2.9·10⁵ s^–1). s‐Triazine itself reacts much more slowly with OH radicals (k = 9.7·10⁷ dm³ mol^–1 s^–1). This can explain, why in the case of atrazine in comparison to other aromatic compounds, e.g. toluene, the addition of the OH radical to the ring (estimated at ca. 40%) is of relatively little importance as compared to an H‐abstraction from (activated) positions of the side groups.  相似文献   

基于线粒体COI和16S rRNA基因研究3个地理群体黑龙江河蓝蛤的遗传多样性     

孙超  刘志鸿  杨爱国  周丽青  吴彪  严加坤  侯丫  董春光 《海洋科学》2015,39(1):39-45

采用通用引物对辽宁盘锦、辽宁大连、山东日照的3个地理群体黑龙江河蓝蛤(Potamocorbula amurensis)COI和16S r RNA序列进行扩增、测序分析,得到30条658bp的COI基因部分序列和27条450 bp的16S r RNA基因部分序列。其中COI和16S r RNA基因部分序列T、C、A、G和A+T的平均含量分别为45.4%和32.0%、13.5%和13.3%、20.7%和29.3%、20.4%和25.3%、66.1%和61.3%,AT含量高于GC含量,这与其他软体动物门动物的COI和16S r RNA的观测结果相近。COI和16S r RNA分别检测到了24个单倍型、43个核苷酸多态位点和9个单倍型、19个核苷酸多态性位点。AMOVA分析表明,3个群体间COI和16S r RNA部分基因总遗传分化系数分别为Fst=0.0090(P0.001)和Fst=0.0674(P0.001),群体内遗传分化远大于群体间、群体内存在较高的遗传分化。用NJ法构建分子进化树,3个地理群体的黑龙江河蓝蛤聚为一个族群,有少数个体和其他群体的个体聚在一起。  相似文献   

南极普里兹湾柱样有孔虫研究          下载免费PDF全文

涂霞  郑范 《极地研究》1996,8(4):50-61

南极普里兹湾柱样ＮＰ９３２含有较多的有孔虫，其中浮游类占２６．３％，底栖类中砂质胶结类占５７．９％，为该柱的优势类群。底栖有孔虫组合以Ｍｉｌｉａｍｍｉｎａａｒｅｎａｃｅａ为典型代表，显示了深水砂质胶结相的面貌。浮游类群中暖与冷水种群的丰度变化，反映了所在海区气温的变化  相似文献   

模糊聚类的DEM确定耕地坡度方法     

朱紫阳 《地理空间信息》2010,8(2):57-59

针对实际应用的坡度计算中没有考虑DEM高程精度影响这一状况,提出采用模糊聚类法进行坡度分级,给出了具体的精度评定方法,并采用我国南方某地区一个镇的第二次土地调查耕地成果数据进行了分析,与传统的直接计算方法进行了比较。结果表明,两种方法得到的图斑坡度级别基本相同;从总体分类精度与Kappa系数计算来看,两者基本接近,模糊聚类法略微优于直接计算法,而且由于其顾及了DEM高程精度的影响,得到的分级结果可靠性更高。  相似文献