琼东南盆地华光凹陷天然气水合物稳定带厚度的影响因素     

刘杰  杨睿  邬黛黛  金光荣  张辉 《海洋学报》2019,41(8):13-25

为了探讨琼东南盆地华光凹陷海底天然气水合物稳定带的分布规律，定量研究了静水压力、底水温度、地温梯度和气源组分对水合物稳定带的影响程度。在此基础上，分析了华光凹陷现今甲烷水合物稳定带的厚度分布。最后，综合各因素的历史演化过程，初步探讨了华光凹陷1.05 Ma BP以来天然气水合物稳定带的演化。结果表明:(1)气源组分和海底温度的变化对研究区内水合物稳定带的影响较大；水合物稳定带厚度与海底温度呈良好的线性负相关性。(2)水深超过600 m的海域具备形成天然气水合物的温压条件；超过600 m水深的海域水合物稳定带厚度大部分超过 100 m，其中西北部稳定带的最大厚度超过300 m，是有利的水合物勘探区。(3)华光凹陷1.05 Ma BP以来天然气水合物稳定带厚度经历了快速增厚–窄幅变化–快速减薄和恢复的过程。麻坑群与水合物稳定变化敏感区在空间上具有较好的叠合关系。结合前人的研究成果，推测其形成与天然气水合物的分解释放有关。  相似文献   

基于Mapbox矢量切片在线配图平台的设计与实现     

任福  黄婷  朱雪坚  翁世杰 《地理信息世界》2018,(4):64-68

矢量切片是以四叉树模型切割矢量数据而生成的矢量要素描述性文件,Web GIS开发中,矢量切片的配图是通过编写Json样式文件,最后浏览器根据样式文件实现地图在线渲染显示,但这种方式配图效率低,样式单一。为了优化配图过程,本文从矢量切片数据和浏览器渲染两个方面提出了一套基于Mapbox的矢量切片在线配图平台,包括基于Geo Server的矢量切片服务发布、基于MapboxGL的浏览器地图渲染等,设计实现了矢量切片在线配图平台应用于浙江省电子地图配图与在线制图研究项目,简化了矢量切片地图的配图过程,具有很强的实用性。  相似文献   

微塑料对海洋桡足类摄食、排泄及生殖的影响     

于娟  许瑞  魏逾杰  田继远  王雪丹  来敬广  陈容  杨桂朋  张正雨  邵云粹 《中国海洋大学学报(自然科学版)》2020,50(3):73-80

微塑料污染目前成为海洋污染普遍关注的一个研究热点。本文在实验室内将青岛近海常见的海洋桡足类猛水蚤暴露于不同浓度的微塑料尼龙6中,研究了猛水蚤的摄食、排泄以及生殖的变化。研究结果表明,微塑料尼龙6对猛水蚤的摄食、排泄、生殖均产生不利的影响,并且存在剂量-效应关系。微塑料尼龙6对猛水蚤摄食率、滤水率、排粪率的24 h·EC 50分别为67.7、62.2、84.1 mg·L^-1,对猛水蚤抱卵率的144 h·EC 50为30.3 mg·L^-1。“饱食感”造成猛水蚤摄食率降低,从而能量和营养摄入不足可能是导致猛水蚤抱卵率降低的原因。猛水蚤对微塑料的摄食,导致猛水蚤排泄的粪便颗粒小型化,由长椭球体变为短小椭球体,可能与其粘度或物理结构的改变有关。暴露于尼龙6的猛水蚤的粪便体积和沉降速率显著低于未暴露微塑料的对照组。本实验结果对于研究微塑料对海洋桡足类以及滤食性浮游动物的生态毒理影响具有一定的帮助。  相似文献   

Clinoform growth and sediment flux into late Cenozoic Qiongdongnan shelf margin,South China Sea     

Si Chen  Ronald Steel  Hua Wang  Rui Zhao  Cornel Olariu 《Basin Research》2020,32(2):302-319

The South China Sea continental margin in the Qiongdongnan Basin (QDNB) area has incrementally prograded since 10.5 Ma generating a margin sediment prism more than 4km-thick and 150–200 km wide above the well-dated T40 stratigraphic surface. Core and well log data, as well as clinoform morphology and growth patterns along 28 2D seismic reflection lines, illustrate the evolving architecture and margin morphology; through five main seismic-stratigraphic surfaces (T40, T30, T27, T20 and T0) frame 15 clinothems in the southwest that reduce over some 200 km to 8 clinoforms in the northeast. The overall margin geometry shows a remarkable change from sigmoidal, strongly progradational and aggradational in the west to weakly progradational in the east. Vertical sediment accumulation rate increased significantly across the entire margin after 2.4 Ma, with a marked increase in mud content in the succession. Furthermore, an estimate of sediment flux across successive clinoforms on each of the three selected seismic cross sections indicate an overall decrease in sediment discharge west to east, away from the Red River depocenter, as well as a decrease in the percentage of total discharge crossing the shelf break in this same direction. The QDNB Late Cenozoic continental margin growth, with its overall increased sediment flux, responded to the climate-induced, gradual cooling and falling global sea level during this icehouse period.  相似文献   

松辽盆地北部上二叠统林西组地球化学特征及地质意义     

张健  张海华  陈树旺  郑月娟  张德军  苏飞  黄欣 《吉林大学学报(地球科学版)》2020,50(2):518-530

为探讨松辽盆地北部林西组地球化学特征、沉积环境及构造背景，对该区黑富地1井所钻遇的上二叠统林西组暗色泥质板岩进行主量元素、微量元素和稀土元素测试分析，结果表明：样品主量元素平均质量分数SiO₂为65.05%、Al₂O₃为17.23%、CaO为2.58%、Na₂O为2.84%、K₂O为3.29%，K₂O/Na₂O值为0.20~3.48，A1₂O₃/（CaO+Na₂O）值为0.41~8.01；稀土元素w（∑REE）值介于80.68×10^-6~215.59×10^-6之间，平均值为173.41×10^-6，δEu值介于0.61~0.88之间，平均值为0.70，表现为Eu的负异常，δCe值介于0.91×10^-6~1.01×10^-6之间，为微弱的Ce负异常，LREE富集，HREE亏损；微量元素以亏损Nb、Ta、Sr，相对富集Rb、Ba、La、Ce、Pb、Nd、Sm为特征。样品元素分析和物源w（TiO₂）-w（Ni）、La/Th-w（Hf）等判别图解表明，林西组沉积物源具有多样性，主要来源于上地壳长英质物源，还有少量来自中、基性岩火成岩物源区。样品微量元素标准化蛛网图，稀土元素球粒陨石标准化配分模式图，K₂O/Na₂O-w（SiO₂）、Th-Co-Zr/10、F₂-F₁构造背景判别图及地球化学参数对比结果表明，松辽盆地北部林西组物源构造背景主要为活动大陆边缘和大陆岛弧，可能形成于靠近大陆岛弧的活动大陆边缘构造背景。林西组应形成于海陆过渡相到陆相环境，水体由半咸水逐渐转变为淡水。  相似文献   

Barium Isotopic Compositions in Thirty‐Four Geological Reference Materials Analysed by MC‐ICP‐MS     

Ya‐Jun An  Xin Li  Zhao‐Feng Zhang 《Geostandards and Geoanalytical Research》2020,44(1):183-199

Measurement of Ba isotope ratios of widely available reference materials is required for interlaboratory comparison of data. Here, we present new Ba isotope data for thirty‐four geological reference materials, including silicates, carbonates, river/marine sediments and soils. These reference materials (RMs) cover a wide range of compositions, with Ba mass fractions ranging from 6.4 to 1900 µg g^?1, SiO₂ from 0.62% to 90.36% m/m and MgO from 0.08% to 41.03% m/m. Accuracy and precision of our data were assessed by the analyses of duplicate samples and USGS rock RMs. Barium isotopic compositions for all RMs were in agreement with each other within uncertainty. The variation of δ^138/134Ba in these RMs was up to 0.7‰. The shale reference sample, affected by a high degree of chemical weathering, had the highest δ^138/134Ba (0.37 ± 0.03‰), while the stream sediment obtained from a tributary draining carbonate rocks was characterised by the lowest δ^138/134Ba (?0.30 ± 0.05‰). Geochemical RMs play a fundamental role in the high‐precision and accurate determination of Ba isotopic compositions for natural samples with similar matrices. Analyses of these RMs could provide universal comparability for Ba isotope data and enable assessment of accuracy for interlaboratory data.  相似文献   

A motion planning algorithm for the feed support system of FAST     

姚蕊  姜鹏  孙京海  于东俊  孙纯 《天文和天体物理学研究(英文版)》2020,(5):117-126

The paper relates to a motion planning algorithm for the feed support system of the Five-hundred-meter Aperture Spherical radio Telescope(FAST).To enhance the stability of the feed support system,the start/termination planning segments are adopted with an acceleration and deceleration section.The source switching planning adopts a combination of a line segment and focal segment to realize stable control of the feed support system.Besides,during the observation trajectory,a transition segment which is not used for observation data is planned with a required time.Through an example simulation,a smooth change is realized via the motion planning algorithm and presented in this paper.  相似文献   

江西省宁都县陂下地热地质特征及资源评价          下载免费PDF全文

刘伟  黄运翠瑶  范超 《华东地质》2020,(4):375-380

摘要: 利用江西省宁都县陂下地区ZK1钻孔取得的相关数据,通过分析该区地温场、基底温度、循环深度、岩石生热率、大地热流、水化学等地热地质特征,对该区地热资源进行了初步评价,并计算了ZK1钻孔的可采资源量和地热产能。研究区地热水井口温度45 ℃,属于HCO₃·SO₄-Na型地热水,可命名为氟水、硅水、温水、淡水; ZK1钻孔可开采资源量为759.89 m³/d,热功率为964.76 kW,年产能5.07×10⁷ MJ。  相似文献   

Comparisons of Salinity Adaptation in Terms of Growth,Body Composition,and Energy Budget in Juveniles of Rainbow and Steelhead Trouts (Oncorhynchus mykiss)     

XIONG Yinghuai  WANG Xin  DONG Shuanglin  WANG Fang  YANG Jingwen  ZHOU Yangen 《中国海洋大学学报(英文版)》2019,(2)

This study examined the effect of different salinities(0, 5, 10, 15, 20, 25 and 30) on the growth performance and energy budget of juveniles of two different ecotypes of Oncorhynchus mykiss, landlocked rainbow trout and anadromous steelhead trout. In the 42 d experiment, fish were cultured in three replicate tanks per salinity treatment(eight fish per tank). At the end of the experiment, the growth of rainbow and steelhead trouts was significantly higher at salinities of 5 and 10, respectively, than at all other salinities. The protein, lipid and energy content of both ecotypes declined with the increase of salinity. Based on their energy budgets, the percentage of energy consumed for growth by rainbow and steelhead trouts were significantly higher at salinities of 5(34.00% ±1.69%) and 10(43.76% ± 1.29%), respectively, than at all other salinities. The percentage of energy consumed for respiration by rainbow and steelhead trouts was lower at salinities of 5(54.90% ± 1.77%) and 10(46.73% ± 0.62%), respectively, than at all other salinities. Our results indicated that the salinity adaptation ability of juvenile steelhead trout was slightly better than that of juvenile rainbow trout, and salinities of 10 and 5, respectively, were most suitable for growth of these two fishes.  相似文献   

国家统一的地理学解释——以东西德统一为例     

何金廖  Hans GEBHARDT  黄贤金  曾刚 《地理学报》2019,74(4):770-779

国家的统一问题一直是关乎区域稳定发展、民族复兴乃至世界和平的大事,然而在地理学领域系统讨论该命题的研究尚不多见。事实上,地理学拥有比政治学和法学更为综合的理论分析体系,尤其是随着政治地理学的快速崛起,从地理学视角解析国家统一的发生机理和影响机制已经日渐成熟。本文从国家主权学说、地缘政治学、后殖民主义、新帝国主义等理论出发,试图构建“国家统一地理学”的分析框架,将国家统一分解为地缘政治重构、经济一体化和文化认同重建3个不同的阶段;并通过东西德国统一的案例分析,深入诠释了德国统一过程中政治版图和地缘格局变化,德国统一后漫长的经济一体化和原西德资本主义的野蛮扩张,以及由于长时间受到不同文化帝国主义渗透带来的民族身份认同分歧问题。德国案例很好地展示了从地理学视角探讨国家统一问题的优越性,同时德国的案例分析可为其他国家的统一问题提供参考与借鉴。  相似文献