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91.
The Xianshuihe fault zone is a seismo-genetic fault zone of left-lateral slip in Southwest China. Since 1725, a total of 59 Ms ≥ 5.0 earthquakes have occurred along this fault zone, including 18 Ms 6.0–6.9 and eight Ms ≥ 7.0 earthquakes. The seismic risk of the Xianshuihe fault zone is a large and realistic threat to the western Sichuan economic corridor. Based on previous studies, we carried out field geological survey and remote sensing interpretation in the fault zone. In addition, geophysical surveys, trenching and age-dating were conducted in the key parts to better understand the geometry, spatial distribution and activity of the fault zone. We infer to divide the fault zone into two parts: the northwest part and the southeast part, with total eight segments. Their Late Quaternary slip rates vary in a range of 11.5 mm/a –(3±1) mm/a. The seismic activities of the Xianshuihe fault zone are frequent and strong, periodical, and reoccurred. Combining the spatial and temporal distribution of the historical earthquakes, the seismic hazard of the Xianshuihe fault zone has been predicted by using the relationship between magnitude and frequency of earthquakes caused by different fault segments. The prediction results show that the segment between Daofu and Qianning has a possibility of Ms ≥ 7.0 earthquakes, while the segment between Shimian and Luding is likely to have earthquakes of about Ms 7.0. It is suggested to establish a GPS or In SAR-based real-time monitoring network of surface displacement to cover the Xianshuihe fault zone, and an early warning system of earthquakes and post seismic geohazards to cover the major residential areas.  相似文献   
92.
The Upper Triassic oil accumulations in the Ordos Basin is the most successful tight oil play in China,with average porosity values of less than 10% and permeability values below 1.0 mD.This study investigated the geological characteristics and origin of the tight oil accumulations in the Chang 6 member of the Upper Triassic Yanchang Formation in the Shanbei area based on over 50,000 petrological,source-rock analysis,well logging and production data.The tight oil accumulation of the Chang 6 member is distributed continuously in the basin slope and the centre of the basin.The oilwater relationships are complex.Laumontite dissolution pores are the most important storage spaces,constituting 30%-60% of total porosity and showing a strong positive relationship with oil production.The pore-throat diameter is less than 1 μm,and the calculated critical height of the oil column is much larger than the tight sand thickness,suggesting that the buoyancy was probably of limited importance for oil migration.The pressure difference between the source rocks and sandstone reservoirs is inferred to have provided driving force for hydrocarbon migration.Two factors of source-reservoir configuration and laumontite dissolution contributed to the formation of the Chang 6 tight oil accumulations.Intense hydrocarbon generation and continuous sand bodies close to the hydrocarbon kitchen are the foundation for the large-scale oil distribution.Dissolution of feldspar-laumontite during the process of organic matter evolution generated abundant secondary pores and improved the reservoir quality.  相似文献   
93.
Scientific research and productive practice for earth history are inseparable from the accurate stratigraphic framework and time framework. Establishing the globally unified, precise and reliable chronostratigraphic series and geological time series is the major goal of the International Commission on Stratigraphy(ICS). Under the leadership of the ICS, the countries around the world have carried out research on the Global Standard Stratotype-section and Points(GSSPs) for the boundaries of chronostratigraphic systems. In the current International Chronostratigraphic Chart(ICC), 65 GSSPs have been erected in the Phanerozoic Eonothem, and one has yet been erected in the Precambrian Eonothem. Based on the progress of research on stratigraphy especially that from its subcommissions, the ICS is constantly revising the ICC, and will publish a new International Stratigraphic Guide in 2020. After continual efforts and broad international cooperation of Chinese stratigraphers, 10 GSSPs within the Phanerozoic Eonothem have been approved and ratified to erect in China by the ICS and IUGS. To establish the standards for stratigraphic division and correlation of China, with the support from the Ministry of Science and Technology, the National Natural Science Foundation of China and the China Geological Survey, Chinese stratigraphers have carried out research on the establishment of Stages in China. A total of 102 stages have been defined in the "Regional Chronostratigraphic Chart of China(geologic time)", in which 59 stages were studied in depth. In 2014, the "Stratigraphic Chart of China" was compiled, with the essential contents as follows: the correlation between international chronostratigraphy and regional chronostratigraphy of China(geologic time), the distributive status of lithostratigraphy, the characteristics of geological ages, the biostratigraphic sequence, the magnetostratigraphy, the geological events and eustatic sea-level change during every geological stage. The "Stratigraphical Guide of China and its Explanation(2014)" was also published. Chinese stratigraphers have paid much attention to stratigraphic research in south China, northeast China, north China and northwest China and they have made great achievements in special research on stratigraphy, based on the 1:1000000, 1:250000, 1:200000 and 1:50000 regional geological survey projects. Manifold new stratigraphic units were discovered and established by the regional geological surveys, which are helpful to improve the regional chronostratigraphic series of China. On the strength of the investigation in coastal and offshore areas, the status of marine strata in China has been expounded. According to the developing situation of international stratigraphy and the characteristics of Chinese stratigraphic work, the contrast relation between regional stratigraphic units of China and GSSPs will be established in the future, which will improve the application value of GSSPs and the standard of regional stratigraphic division and correlation. In addition, the study of stratigraphy of the Precambrian, terrestrial basins and orogenic belts will be strengthened, the Stratigraphic Chart of China will be improved, the typical stratigraphic sections in China will be protected and the applied study of stratigraphy in the fields of oil and gas, solid minerals, etc. will be promoted. On the ground of these actions, stratigraphic research will continue to play a great role in the social and economic development of China.  相似文献   
94.
文章对云南会泽铅锌矿床的黄铁矿、方铅矿和闪锌矿中的分散元素进行了电子探针分析(EMPA),探讨了分散元素的富集机制.结果表明,分散元素含量已达到综合利用指标,且富集规律为:分散元素以类质同象的形式赋存,黄铁矿中分散元素含量较低,而方铅矿中分散元素的含量稍高于闪锌矿.闪锌矿中:Cd富集顺序为红色>杂色>黑色,在高温阶段Cd置换Fe,低温阶段Cd置换Zn;Ga通过置换Zn进入闪锌矿,Ge可能主要替代Fe而进入闪锌矿晶格.方铅矿中:Cd和Ga元素置换Fe或Pb先进入方铅矿晶格内,Ge则富集较晚,具体表现为:当Ga含量较低时,元素进入方铅矿品格顺序为Fe,Zn→Cd→Ga,Ge,当Ga含量较高时,元素进入方铅矿品格的顺序依次为Cd,Ga→Ge.  相似文献   
95.
通过野外采样、化学分析、电子探针(EPMA)和X射线衍射(XRD)分析等手段,研究了贵州织金地区黑色页岩矿物成分、化学组分、微量元素、稀土元素特征。研究区矿样化学成分以SiO_2和Al_2O_3为主,且具有高K低Na的特征。电子探针和X射线衍射分析表明,研究区黑色页岩主要矿物组成有石英、粘土矿物、白云石及黄铁矿等。织金黑色页岩中Pb、Ni、U、V、Cr等金属元素存在不同程度的富集,稀土元素总量为153.2×10~(-6)~224.89×10~(-6),属轻稀土元素富集型。同时从多金属层、页岩气、页岩提钾及近底部含磷铀矿资源等方面讨论了织金黑色页岩资源化利用。织金黑色页岩多金属层含有Mo、V、Ni、Ag及U等多金属元素,具综合利用价值;其中有机碳含量达到页岩气开发大于2%的条件,可进一步开展研究;页岩中伊利石含量较多,可提取黑色页岩中的钾制备含钾复合肥;黑色页岩底部与磷矿层接触带产出磷铀矿,主要为胶状磷铀矿,接触带可作为铀矿找矿的标志层。  相似文献   
96.
海洋生态环境目前正在承受来自人类活动和气候变化的巨大压力;急需必要的管理工具或决策支持系统来应对这些压力所带来的生态环境问题。对海洋生境的分类识别是开展生物多样性保护的基础和前提;海洋生态重要区识别作为一种客观、科学和灵活的生境分类评估和选划方法;已被科学界和管理者广泛接受和认可。本文首先介绍了海洋生态重要区的概念内涵以及识别方法的研究进展;给出了海洋生态重要区的定义;之后以黄河口为例;初步建立了针对该区域的生态重要区识别标准和评价方法;对黄河口及邻近海区进行了生态重要性等级划分。本文是对生态重要区识别方法在我国近海的首次应用尝试;研究结果可为我国基于生态系统的海洋管理提供科学方法和工具;也可为其他区域的研究提供借鉴。  相似文献   
97.
磷酸甘露糖变位酶(PMM)是褐藻胶和岩藻聚糖合成过程中的关键酶之一。本研究利用c DNA末端快速克隆(RACE)技术,获得2条海带PMM基因(Sjpmm1,Sjpmm2)序列。其中,Sjpmm1的开放阅读框(ORF)长759 bp,其编码的Sj PMM1为卤酸脱卤酶(HAD)超家族成员,含252个氨基酸,分子量约为28.51 k Da;而Sjpmm2的ORF长1866 bp,其编码的Sj PMM2属于磷酸己糖变位酶超家族的成员,含621个氨基酸,分子量约为66.49 k Da。海带PMM的二级结构均以?-螺旋为主。进化分析表明,Sjpmm1来自于原始真核生物,而Sjpmm2来源于质体的第一次内共生作用。实时定量PCR分析发现,海带受到高温或低温胁迫时,Sjpmm1和Sjpmm2转录水平上升,以合成岩藻聚糖抵抗环境影响。此外,利用p MAL-c5X载体对Sj PMM1进行体外表达,得到高浓度的可溶性融合蛋白,为后续的Sj PMM功能分析提供基础。  相似文献   
98.
文章利用舟山海洋环境监测站2014年第16号台风"凤凰"过境影响期间,对OS071X测波雷达和3m波浪浮标在同一海域内的波浪探测资料进行了对比验证。通过分析,OS071X测波雷达探测反演的有效波高、周期与3m波浪浮标探测结果对比,二者按先后顺序的均方根误差分别为0.27m和0.29m,相关系数分别为0.93和0.90。结果表明,OS071X测波雷达系统的探测精度得到了验证,能够满足实时探测近岸海域波浪的需求。  相似文献   
99.
本研究以硫酸镁作为麻醉剂,比较了在不同水温条件下硫酸镁对仿刺参幼参的麻醉效果,分析了不同浓度硫酸镁对仿刺参幼参的麻醉效果。实验水温设置11℃、13℃、15℃、17℃、19℃和21℃六个温度梯度,实验用仿刺参幼参规格分为大规格(L)40.26±1.84g、中规格(M)21.83±1.72g、小规格(S)11.03±1.63g。实验结果显示:1.在硫酸镁麻醉剂浓度相同时,仿刺参规格越大麻醉所需时间越长,复苏时间却越短;随着麻醉剂浓度增加,对仿刺参幼参麻醉时间相应缩短,但复苏时间呈现逐渐延长。不同浓度硫酸镁麻醉剂对不同规格仿刺参的麻醉效果具有显著差异(P0.05)。2.在水温11℃~20℃范围内,随着水温的升高,对仿刺参幼参的麻醉时间从26.13±17.78min缩短到21.47±3.52min,但复苏时间从26.13±17.78min增加到71.05±12.32min,不同水温条件下硫酸镁对仿刺参幼参麻醉效果影响显著(P0.05)。研究表明,仿刺参体重在20g以下的适宜麻醉浓度为0.1~0.25mol·L-1,体重在20g以上的适宜麻醉浓度为0.25~0.35mol·L~(-1)。  相似文献   
100.
海洋经济已成为我国新的经济增长点,山东省作为全国海洋资源大省,海洋经济占山东省整体经济比重较大且逐步增强,海洋经济建设是山东省经济腾飞的重要驱动。在国际化趋势大背景下,入境旅游业成为海洋经济发展的新引擎,但因金融危机暴发和全球经济触底,山东省入境旅游业和海洋经济发展随之减速。在中韩自贸区和“21世纪海上丝绸之路”建设契机下,通过入境旅游业推动并支持海洋经济发展成为重要着力点。文章通过中介传导模型,利用回归分析,根据相关统计数据,研究山东省海洋经济、入境旅游业与经济发展的关系,并针对研究结果提出相关政策建议。  相似文献   
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