1971-2010年三江源地区干湿状况变化的空间特征   总被引：5，自引：1，他引：4       下载免费PDF全文

徐维新  古松  苏文将  江莎  校瑞香  肖建设  张娟 《干旱区地理》2012,35(1):46-55

 依据1971-2010年地面观测气象数据,计算了三江源地区湿润指数。利用经验正交函数分解（EOF）和偏相关系数,对近40 a三江源地区干湿状况变化的时空特征及其影响因素进行了分析。结果表明:三江源地区干湿状况的变化在其北部与南部、东部与西部间存在明显反相位变化特征。北部和东部的部分区域分别在20世纪90年代和21世纪后表现出气候湿润化趋势,其余大部地区的持续干旱化趋势始于20世纪80年代初,其中南部与西部变干趋势显著,其湿润指数线性趋势率达到-8%/10 a。虽然三江源地区干湿状况主要决定于降水量和相对湿度的变化,但20世纪90年代中期后气温的显著上升,使得气温也成为关键的影响因子之一,即使在降水明显增加的背景下,也引起三江源主体区域湿润指数的明显下降。气候变暖情景下,北部和东部地区在近十几年暖湿化趋势明显,其余大部地区表现为不同程度的暖干化趋势。  相似文献   

地球深部流体中的有机质与金刚石生长北大核心CSCD     

Frezzotti  M.L袁超 《矿物岩石地球化学通报》2019,(6):1080-1080

金刚石代表了地球深部微量的碳存在,其成因对于理解行星演化的动力学机制、挥发分循环以及氧化还原状态演变等具有重要意义。在俯冲带环境,金刚石的形成和挥发分的循环密切相关。地球内部的碳通量主要受变质脱碳作用和碳酸盐溶解作用形成的相对氧化的水质流体的调节和控制。在深部C-H-O流体中,碳由随流体迁移到最终饱和形成金刚石的过程主要受碳在流体中溶解度的控制,而后者则受高温高压条件、pH值、氧化还原环境、溶质结构和岩石中缓冲矿物组合等多种因素的影响。  相似文献   

基于断层摩擦强度的地应力计算模型     

丁九龙  孟召平  徐文娟  张娟 《工程地质学报》2017,25(2):504-510

浅部断层附近的应力状态是影响地下硐室工程和石油勘探与开发的重要影响因素,浅部断层附近的岩石因构造运动处于弱胶结状态,常规的地应力测量方法在该处测量存在误差较大、成本较高、周期较长等不足。为此,本文在莫尔-库仑强度理论基础上,系统分析了断层附近的应力方向、断层摩擦系数定量化计算及断层摩擦强度之间的关系。文章最后将该地应力计算模型应用于成庄区域,与实测地应力吻合较好。研究结果对于地应力计算及油气田的安全高效生产具有指导意义。  相似文献   

利用GPS数据估算川滇南部地震（MSge;6.5）平均复发间隔          下载免费PDF全文

张效亮  )　谢富仁)　史保平) 《地震学报》2010,32(1):23-32

利用川滇南部GPS站点速度资料,采用Kriging插值和有限单元中形函数（拉格朗日差值函数）求导原则,计算了川滇南部主应变速率.在此基础上,引入Kostrov地震矩率计算方法,由主应变速率求得了研究区的地震矩率,进而借助于Ward地震平均复发间隔公式计算了研究区地震（MSge;6.5）平均复发间隔.计算结果表明,川滇南部不同震级档地震复发间隔空间分布总体上与区内主要活动断裂展布基本吻合;地震复发间隔低值区主要分布在地震活动水平和滑动速率较高的安宁河——则木河——小江断裂带、丽江——小金河断裂西南段、红河断裂西北段.所得的结果与利用历史地震资料获得的结果基本一致.该方法对于历史地震资料缺乏或不完整地区和活动断层定量研究程度较低的地区有着潜在的应用价值.   相似文献   

磁相变与地壳地球物理异常   总被引：1，自引：0，他引：1       下载免费PDF全文

L.SZARKA  J.KISS  E.PR 《地球物理学报》2010,53(3):612-621

我们曾提出过一种可能导致地磁和地壳电导率异常的来源：地壳中的二级磁相变,即居里（尼尔）深度附近磁化率的显著提高.这一现象能很好地解释一些来源不明的地磁异常.本文总结了在中地壳深度处、薄且高磁导率异常体的一维和多维大地电磁特征.高磁导率层引起的异常与高电导率层导致的异常相比,大小上可相比拟,但符号相反.无论在什么情况下,经典的大地电磁解释容易导致一个不真实的极厚高阻层,并且在地磁异常附近有与之对应的空间波长,二级磁相变也被认为是这一现象的可能解释.尽管在地壳中是否存在二级磁相变还有一定争议,但最近的一些固体物理实验结果进一步表明它可能是地壳各种地球物理异常的来源之一.  相似文献   

辽宁1999年MS5.9岫岩地震的剪切波分裂特征s          下载免费PDF全文

太龄雪)高原)曹凤娟)石玉涛)吴晶  )焦明若) 《地震学报》2008,30(4):340-354

利用辽宁遥测数字地震台网营口台的地震波形资料,采用高原等剪切波分裂SAM分析方法,对1999年11月29日辽宁省岫岩MS5.9（ML5.3）地震前后的地震序列进行了剪切波分裂分析. 通过对营口台的资料分析表明,快剪切波优势偏振方向为ENE-WSW向,与该地区主压应力方向一致,也与华北区域构造应力场方向一致;平均慢剪切波时间延迟在岫岩地震前显示增加,可能反映了震前的应力积累过程. 营口台的快剪切波优势偏振方向还与小地震活动空间分布走向一致,与活动断层走向相关. 快剪切波偏振的月平均变化直方图也显示,地震前两个月快剪切波偏振方向似乎也有变化,但这个现象还需要更多资料的证实.   相似文献   

关于通报表扬在全国县（市）、乡（镇）、村级干部国土资源法律知识宣传教育培训活动中成绩突出单位和个人的通知     

国土资源部全国县 《国土资源通讯》2009,(3):12-19

国土资发〔2009〕13号各省、自治区、直辖市党委组织部、宣传部,国土资源厅（局）、教育厅（教委）、司法厅（局）、广播电影电视局,各派驻地方的国家土地督察局,中国地质调查局及国土资源部其他直属单位。国土资源部机关各司局： 为贯彻落实党的十七大精神，深入学习实践科学发展观，坚持节约和合理利用资源的基本国策，推进国土资源法律法规知识的普及，使坚守18亿亩耕地红线和合理开发利用矿产资源成为广大基层干部群众的自觉行动，  相似文献   

Expression of the Phycoerythrin Gene of Gracilaria lemaneiformis (Rhodophyta) in E. coli and Evaluation of the Bioactivity of Recombinant PE   总被引：1，自引：0，他引：1  

WEN Ruobing)  SUI Zhenghong)  *  ZHANG Xuecheng)  ZHANG Shuang)  and QIN Song) ) Laboratory of Marine Genetics  Breeding  College of Marine Life Sciences  Ocean University of China  Qingdao  P. R. China ) Institute of Oceanology  Chinese Academy of Sciences  Qingdao  P.R. China 《中国海洋大学学报(英文版)》2007,6(4):373-377

Phycoerythrin (PE) is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cytotoxic and hydroxyl radical assay were preformed to detect the bioactivity of recombinant PE. Recombinant plasmids pGEX-PE and pBGL were transformed into E.coli BL21 to make two recombinant strains BEX (pGEX-PE) and BGL (pBGL). PE expressing in BEX (pGEX-PE) was validated by SDS-PAGE and Western blotting analysis. SDS-PAGE analysis indicated that the PE-GST fusion protein was mostly inclusion bod- ies. Specific expression of PE was confirmed by Western blotting analysis. The recombinant E. coli BEX (pGEX-PE) cells were col- lected and sonicated. The supernatants were reserved for the tumor cytotoxic experiments. The result of tumor cytotoxic assay indi- cated that the supernatants containing PE had the activity of inhibiting the growth of Hela cells and with the increase of protein con- centration, the inhibiting rate increased from 37.31% to 63.26%, which showed significant difference from the control. Hydroxyl radical scavenging effect was tested with supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates treated with sonication and heating. For the sonication samples, the scavenging rates of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were significantly higher than the negative control BL21(pGEX-4T) (P<0.02), and the scavenging rates increased slowly following the increase of the protein content. For the heating samples, except for the 0.2 mg mL-1 BGL (pBGL) products, the scavenging effects of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were stronger than that of negative control BL21(pGEX-4T). However, the effect intensity was not positively correlated with the increase of the protein concentration. Though a partially de- creased hydroxyl radical scavenging activity was led by heating, the biological activity was still retained and conspicuous. This re- search showed that phycoerythrin protein expressing in E. coli has the potential medical and sanitarian value.  相似文献   

Nodes and Field of Tourist Origins to Ancient Village——A Case Study of Huangcheng Village in Shanxi Province of China     

ZHONG Jing  ZHANG Jie  LI Donghe    ZHAO Yong  LU Song    SHI Chunyun 《中国地理科学(英文版)》2007,17(3):280-287

Based on Hagget's theory of spatial structure,researches on the nodes and field of tourist origins to Huang-cheng Village in Shanxi Province of China have been explored.Nodal hierarchy structure of tourist origins is analyzed with cluster analysis and the gravity model.And field of tourist origins is analyzed with attraction radius index(R)and geography concentration index(G).In the field analysis,R and G of Huangcheng Village are compared with Xidi Village that is a world heritage located in Huangshan City of Anhui Province in China.According to comparison of loca-tions of two areas,influential factors for field area of Huangcheng Village are identified.It is concluded that:1)cluster analysis and gravity model can be complementary methods to each other for nodal hierarchy structure analysis of tour-ist origins;and 2)as far as location is concerned,the weak intensity effect of tourism resources in the tourist region is a major cause for explaining why tourist origins to Huangcheng Village are mainly its neighboring areas.Moreover,it is suggested that the regional effect of tourist resources should be regarded as a component of destination attractiveness when applying gravity model.  相似文献   

Current and Thermohaline Characteristics of the Arabian Sea During January 1998     

CHEN Meixiang)  ZUO Juncheng)  LI Peiliang)  DU Ling)  and LI Lei)) Oceanography Department  Ocean University of China  Qingdao  P. R. China ) Key Laboratory of Coastal Disaster  Defence  Ministry of Education  Hohai University  Nanjing  P. R. China 《中国海洋大学学报(英文版)》2007,6(2):117-124

Based on a ship survey during January 1998, the characteristics of the flow, the thermohaline properties and the volume transport of the Arabian Sea are discussed. A strong westward flow exists between 10.5?N and 11?N, part of which turns to the south as the Somali current near the coast at about 10?N and the rest turns north. At the passage between the African continent and the So- cotra Island, the northern branch separates into two flows: the left one enters the passage and the right one flows eastward along the southern slope of the island. Off the island the flow separates once more, most of it meandering northeast and a small fraction flow- ing southeast. Volume transport calculation suggests that the tidal transport is one or two orders of magnitude smaller than the total transport in this region and it becomes more important near the coast. The average velocity of the flow in the upper layer (0-150 m) is about 20 cm s-1, with a maximum of 53 cm s-1 appearing east of the Socotra Island, and the subsurface layer (200-800 m) has an aver- age velocity of 8.6 cm s-1; the velocity becomes smaller at greater depths. The depth of the seasonal thermocline is about 100 m, above which there is a layer with well mixed temperature and dissolved oxygen. High-salinity and oxygen-rich water appears near the surface of the northern Arabian Sea; a salinity maximum and oxygen minimum at 100 m depth along 8?N testifies the subduction of surface water from the northern Arabian Sea. Waters from the Red Sea and the Persian Gulf also influence the salinity of the area.  相似文献