锯缘青蟹Scylla serrata幼体形态观察     

曾朝曙  李少菁  曾辉 《广东海洋大学学报》2001,21(2):1-6

描述了锯缘青蟹各期幼体的外部形态.青蟹在环境条件不适、营养不良情况下,会出现异常的额外的第六期蚤状幼体.绘图表达了各期幼体重要特征.  相似文献   

我国某些历史地貌学问题的刍议   总被引：1，自引：0，他引：1  

曾昭璇 《地理研究》1983,2(2):12-19

本文提出历史地貌学是地貌学的一个组成部分,它主要研究人类历史时期地貌的变迁.它在理论上能对地貌学上一些基本理论给予证实或提供重要依据;在生产上能按历史演变过程提出一些建设性意见,为有关建设部门参考.并举珠江三角洲水道及黄河下游的整治意见为例.说明历史地貌学能对生产建设提供科学依据.  相似文献   

Prediction and verification of earthquakes induced by the Xiluodu hydropower station reservoir          下载免费PDF全文

Tinggai Chang  Baohua Li  Xinxiang Zeng 《地震科学（英文版）》2022,35(5):387-397

Research has been conducted on reservoir-induced earthquakes in China since the Xinfengjiang reservoir-induced earthquakes in the 1960s. Regulations now require the risk of reservoir-induced earthquakes to be evaluated in the pre-research stage of all hydropower projects. Although nearly 40 cases of reservoir-induced earthquakes have been reported in China, analyses comparing the changes in seismic activity following reservoir impoundment with predictions are rare. In this study, we compared seismic activities observed in the reservoir area before and after the impoundment of the Xiluodu hydropower station in terms of the spatial distribution, frequency, and focal depths of the earthquakes, and clarified the correlation between their frequency/timing and reservoir level after impoundment. We then concluded that the seismic events in the head region were karst-type earthquakes, while those in the second segment of the reservoir were tectonic earthquakes. The spatial distribution of the earthquake epicenters and the seismic intensities validated some of the results for the reservoir-induced seismic risk assessment for the Xiluodu hydropower station, indicating that the proposed earthquake triggers and predictive models are reasonable. This study can provide a valuable reference for investigating the mechanism (s) of reservoir-induced earthquakes, revising reservoir-induced earthquake hazard assessment codes, and predicting the hazard zones of reservoir-induced seismicity under similar conditions.  相似文献   

High-resolution structure-from-motion models covering 160 km-long surface ruptures of the 2021 MW 7.4 Madoi earthquake in northern Qinghai-Tibetan Plateau     

Jing Liu-Zeng  Wenqian Yao  Xiaoli Liu  Yanxiu Shao  Wenxin Wang  Longfei Han  Yan Wang  Xianyang Zeng  Jinyang Li  Zijun Wang  Zhijun Liu  Hongwei Tu 《地震研究进展（英文）》2022,2(2):100140

The 22 May 2021 M_W 7.4 Madoi, Qinghai, China earthquake presented a rare opportunity to apply the modern unmanned aerial vehicle (UAV) photography method in extreme altitude and weather conditions to image surface ruptures and near-field effects of earthquake-related surface deformations in the remote Tibet. High-resolution aerial photographs were acquired in the days immediately following the mainshock. The complex surface rupture patterns associated with this event were covered comprehensively at 3–6 cm resolution. This effort represents the first time that an earthquake rupture in the interior of the Qinghai-Tibetan Plateau has been fully and systematically captured by such high-resolution imagery, with an unprecedented level of detail, over its entire length. The dataset has proven valuable in documenting subtle and transient rupture features, such as the significant mole-tracks and opening fissures, which were ubiquitous coseismically but degraded during the subsequent summer storm season. Such high-quality imagery also helps to document with high fidelity the fractures of the surface rupture zone (supplements of this paper), the pattern related to how the faults ruptured to the ground surface, and the distribution of off-fault damage. In combination with other ground-based mapping efforts, the data will be analyzed in the following months to better understand the mechanics of earthquake rupture related to the fault zone rheology, rupture dynamics, and frictional properties along with the fault interface.  相似文献   

成矿模式与找矿模式研究的现代科学技术     

曾庆栋  底青云  薛国强  王功文  荆林海 《地学前缘》2021,28(3):295-308

为保障资源的可持续发展,地下深部资源勘探与开发是当前国内外许多国家重要的战略选择。地下深部是否存在优质矿产资源研究是开展深部找矿的前提。理想的成矿模式对指导找矿模式的构建具有重要的理论意义,而合理找矿模式的建立对于深部找矿具有重要的指导意义。随着现代科学技术的持续发展,各种新技术不断用于地质研究及勘探中,使深入理解成矿作用,建立理想的成矿模式成为可能。目前,一些新技术如矿物原位U-Pb定年、原位成分、原位同位素分析等在成矿模式研究中已发挥重要作用,指导人们重新建立新的成矿模式;同样一些地球物理探测技术、地球化学探测技术等也正在找矿模式的建立中发挥重要作用,为深部矿的找寻提供更可靠的依据。因而成矿理论及综合地球物理、综合地球化学等现代科学技术的应用是当前及未来深部矿找矿工作的趋势。  相似文献   

信息动态     

张贵宾  刘良  魏春景  肖益林  焦淑娟  吕增  张立飞 《矿物岩石地球化学通报》2021,40(6):1230-1249

变质岩是组成硅酸盐地球的三大岩石之一,对了解深部地壳的组成和地壳演化、研究地壳热结构历史记录、恢复变质岩原岩建造和指导找矿都具有重要意义.本文综述了近十年来我国变质岩学科在超高压/高温变质作用、相平衡、变质流体以及变质岩地球化学等几方面的研究进展.在已有研究基础上,近十年来我国学者又相继在柴北缘野马滩、南阿尔金、东昆仑、北秦岭及西南天山的不同类型岩石中发现了柯石英、斯石英假象(副象)以及其他一些特征的超高压变质指示矿物和结构,确定了这些超高压变质带的野外分布特征.在超高温变质作用研究方面,识别并确定了华北克拉通孔兹岩带超高温变质岩石的出露规模,准确的变质时代和时间尺度的限定以及P-T-t轨迹的构建,尤其是在进变质阶段的确定方面取得了一系列进展.在变质相平衡研究方面,在热力学数据库和矿物相及熔体活度模型进一步完善的基础上,开发了新的模拟计算软件GeoPS,建立了基于ACF组分分析的变质基性岩完整相平衡关系;同时在深熔作用与花岗质岩石成因的定量模拟方面也有重要进展.在矿物温压计研究方面,首次建立了与斜长石无关的GBAQ压力计、二云母压力计和白云母Ti温度计.在元素地球化学方面,高场强元素(如Ti、Nb、Ta、Zr、Hf等)和卤族元素(如F、Cl、Br和I)在变质脱水过程中的迁移和分异,以及变价元素(如V、Fe、W和Mo等)对指示氧逸度的变化研究方面都取得了一系列进展.在变质流体研究方面,对俯冲带高压-超高压流体活动的证据、流体成分的确定及流体活动时限等方面的研究也取得了明显进展.  相似文献   

四川盆地东部中二叠统茅口组热液活动特征^*          下载免费PDF全文

李红  王良军  柳益群  曾韬  张冬冬  李文厚  周鼎武  杨康  董杨坤  彭毅峰 《古地理学报》2021,23(1):153-174

四川盆地中二叠统茅口组存在丰富的热液流体活动。在野外剖面和岩心观察的基础上,利用多种分析测试方法,对四川盆地东部茅口组碳酸盐岩中的热液活动特征进行了探讨。研究区茅口组热液活动包括2类,一类为硅质热液,表现为薄层硅质岩或硅质团块;另一类为碳酸盐型热液,表现为粗晶方解石和白云石充填在张性构造裂缝中或呈“雪片状”集合体,偶见少量黄铁矿、闪锌矿等金属硫化物伴生。硅质岩主量元素之间的关系表明硅质来源具有多样性,是热液硅与壳源硅的混合;黄铁矿、闪锌矿原位S同位素 δ³⁴S 介于-3.91‰~-6.87‰之间,推测可能受到了微生物和基性岩浆岩的双重影响;方解石脉和具鞍状双晶的白云石脉普遍具有CaO高于标准计量、相对富Sr和U、贫REE和Ti、Ce/Ce^*明显负异常、Eu/Eu^*主体正异常、Y正异常等特征,表明碳酸盐脉为热液活动的产物,流体来源也呈现出火山活动相关流体与富钙地下水混合的特点。闪锌矿富集Ge和Cd,Zn/Cd及Zn/Fe值反映了中等成矿温度。硅质岩和碳酸盐流体包裹体均一温度变化范围较大,介于54.7~294.3 ℃之间,与稀土元素和微量元素比值所揭示的特征吻合。研究结果表明,穿层状硅质结核和团块的首次出现往往标志着茅口组热液活动的开始,而张性构造裂缝和碳酸盐型热液活动带来的围岩白云化作用则有效地改善了白云岩储集层的物性。  相似文献   

南黄海盆地中部隆起中—古生界海相油气多期成藏——来自CSDP-2井的勘探启示     

蔡来星  肖国林  万慧清  曾志刚  张训华  郭兴伟  吴志强 《吉林大学学报(地球科学版)》2021,51(2):307-324

大陆架科学钻探CSDP-2井不仅完成了南黄海盆地中部隆起的首次钻探,也创造了陆架区2 843.18 m的全取心深钻记录。在CSDP-2井钻遇的三叠系青龙组（T₁q）,二叠系大隆组（P₃d）、龙潭组（P_2-3l）、孤峰组（P₂g）、栖霞组（P₁q）和志留系坟头组（S₁f）等多层段岩心中探获了多类型、多级别的油气显示,且二叠系3个油砂样品表明该区曾经历过大规模的油气运聚过程。地球化学分析、油源对比结果表明：1^#油砂和2^#油砂层段均表现出"近源成藏"的特征,其中大隆组1^#油砂中的原油与大隆组、龙潭组上段泥岩的亲缘关系明显,龙潭组2^#油砂中的原油与龙潭组下段、孤峰组和栖霞组烃源岩具有更好的亲缘关系;3^#油砂中的原油成熟度明显偏低,推测其可能来自两侧坳陷区的白垩系、古近系烃源岩;盆地模拟和含烃流体包裹体测温相互印证,明确了CSDP-2井揭露的四套烃源岩与三套储集层之间存在着"接力式"生烃和"波浪式"充注的多期成藏特征,同时得益于三套盖层的良好封盖,彰显了研究区较为广阔的海相油气勘探前景。  相似文献   

Atmospheric Correction Methods for GF-1 WFV1 Data in Hazy Weather     

Zheng Wang  Junshi Xia  Lihui Wang  Zhihua Mao  Qun Zeng  Liqiao Tian  Liangliang Shi 《Journal of the Indian Society of Remote Sensing》2018,46(3):355-366

Increasing hazy weather in the eastern area of China limits the potential application of high-resolution satellite data and poses a huge challenge for the atmospheric correction of remote sensing images. Consequently, it is necessary to find the most suitable atmospheric correction method under hazy condition. In this study, five kinds of atmospheric correction models, including 6S, COST, FLAASH, QUAC, and ATCOR2, are applied to the GaoFen-1 Wild Field Camera (GF-1 WFV1) data in the eastern area of China, and examined by both quantitative and qualitative analyses using the measured spectrum data. Experimental results indicated that ATCOR2 achieves the best performance among the atmospheric correction methods qualitatively and quantitatively. Hence, specifically for the study area and GF-1 WFV1 dataset, ATCOR2 is the most suitable atmospheric correction approach under hazy in the eastern area of China.  相似文献   

微服务在气象数据服务中的应用研究     

曾行吉  任晓炜  宋瑶  梅宁光 《气象研究与应用》2019,40(1):80-83

在气象数据服务逐渐接口化背景下,MUSIC作为CIMISS气象数据接口服务的主要系统,得到了各级业务部门的广泛应用,但也存在不完善和使用难等问题。基于MUSIC以微服务架构设计与开发气象数据服务系统,扩充了MUSIC接口,实现了接口编制、编排和图形化使用,提升了接口使用人性化水平,增强了MUSIC业务支撑能力和业务适应性。  相似文献