胶东地区破碎带蚀变岩型金矿时代的测定及其地质意义   总被引：30，自引：4，他引：26  

杨进辉  周新华  陈立辉 《岩石学报》2000,16(3):454-458

通过对胶东半岛西北部超大型破碎带蚀变岩型金矿 -新城金矿的强烈热液交代成因黄铁绢英岩 Rb- Sr等时线法测年 ,获得 116 .6± 5 .3Ma成矿年龄。结合本区焦家、仓上等大型 -超大型金矿蚀变矿物、石英流体包裹体的 Rb- Sr等时线年龄、K- Ar年龄 (10 5± 7Ma;10 6± 2 Ma;113.5± 0 .6 Ma)等前人成果 ,确定胶东半岛西北部破碎带蚀变岩型金矿成矿时代主要集中在 10 0～ 117Ma。与围岩花岗岩、花岗闪长岩的成岩年龄 (16 0～ 15 0 Ma;130～ 12 6 Ma)存在着近 10 Ma的时差 ,并根据(87Sr/ 86 Sr) i比值以及已有的 C、H、O稳定同位素资料表明 ,即使成矿物质部分来源于围岩花岗岩类 ,但成矿作用与岩浆活动无明显的成因关系 ,而是深部循环的大气降水或幔源 C- H - O流体参与成矿作用的结果  相似文献   

TECTONIC CHARACTERISTICS AND EVOLUTION OF THE QIANGTANG BASIN IN NORTHERN TIBET PLATEAU     

Huang Jijun  Yi Haisheng  Lin Jinhui  Liu Yuanchao 《地学前缘》2000,(Z1)

TECTONIC CHARACTERISTICS AND EVOLUTION OF THE QIANGTANG BASIN IN NORTHERN TIBET PLATEAU  相似文献   

中国开辟区多金属结核粒径分析及其意义   总被引：5，自引：5，他引：0  

陶春辉  陈建林  钱鑫炎  张金辉 《海洋学报》2000,22(1):76-83

为了便于多金属结核的开采、结核分布规律的探讨和矿藏储量计算,对DY85-4航次所取得的多金属结核抽样样品进行了逐个三轴粒径测量和称量工作,并进行了统计分析和分形研究,得到了多金属结核的粒径统计分布规律。从而为集矿机的设计提供了科学依据。  相似文献   

Precipitation regional extreme mapping as a tool for ungauged areas and the assessment of climate changes          下载免费PDF全文

Jinhui Jeanne Huang  Yu Li  Junxian Yin  Edward Authur Mcbean 《水文研究》2016,30(12):1940-1954

The spatial‐temporal characteristics of mean annual daily maximum precipitation events in the upper Yangtze River basin in China are examined using a framework termed precipitation regional extreme mapping (PREM). The framework consists of regional analyses and mapping methods, which have the capability to assess the presence or absence of climate change. The findings confirm the homogeneous regions identified by Wang (2002) using a heterogeneity measure, where all three regions have heterogeneity less than 1.0. The Pearson type III (PE3) distribution was found to be acceptable for all three regions, while the generalized extreme‐value distribution performs better than PE3 for Region I (eastern portion of the upper Yangtze basin). Two indices, root mean square error and mean bias, were used to access the performance of the extreme map, and the results show that the map of extreme can predict precipitation for ungauged regions with acceptable accuracy. The regional frequency maps were used in conjunction with the Student's t‐test to identify the statistical significance of changes of extremes in precipitation. Results indicate that there have been no significant changes in maximum daily precipitation magnitudes over the past four decades, a finding that is valuable for the safe planning of major hydraulic projects and the management and planning of water resources in the upper Yangtze River basin. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

复杂山区三维地震勘探野外施工方法          下载免费PDF全文

王晶  姜飞  李京涛  李金辉  陶二勇 《山东国土资源》2014,30(1):48-50

三维地震勘探项目野外复杂的地表情况直接影响地震资料的采集难度和采集质量。通过对河南、内蒙古、新疆、山西等多个省份难度高的复杂山区野外项目现场实际施工经验分析,总结出一些针对复杂山区野外施工的特殊方法,可以有效的降低野外施工成本,提高野外施工效率和质量。  相似文献   

Seasonal statistical analysis of the impact of meteorological factors on fine particle pollution in China in 2013–2017     

Xuewei Hou  Dongdong Fei  Hanqing Kang  Yinglong Zhang  Jinhui Gao 《Natural Hazards》2018,93(2):677-698

Based on long-term PM_2.5 data observed at high temporal and spatial resolution, the relationships between PM_2.5, primary emission, and weather factors in China during four seasons were examined using statistical analysis. The results reveal that primary emission plays a decisive role in the spatial distribution and seasonal variability of PM_2.5, except in western China, where PM_2.5 is controlled by dust weather. In addition to the accumulation of primary emissions, unfavorable meteorological conditions for the diffusion of air pollution lead to the occurrence of PM_2.5 pollution. The significant dynamic factors affecting PM_2.5 concentration are surface wind speed, planet boundary layer height, and ventilation coefficient, especially in winter. The ventilation coefficient is inversely correlated with PM_2.5. Better ventilation is more favorable for the dilution and outflow of local PM_2.5. However, in spring and autumn, ventilation coefficient and PM_2.5 are positively correlated over the southern regions with low emission, indicating that ventilation also affects the inflow of PM_2.5 from outside the region. Wind shear, 850 hPa divergence, and vertical velocity have insignificant effects on the long-term variations in PM_2.5. The significant thermal factor is 850 hPa temperature in winter, except in the Pearl River Delta and Xinjiang regions. In spring, the influence of each thermal factor is weak. In summer, the influences of temperature and humidity are more significant than in spring. In autumn, the influence of humidity is relatively obvious, compared with other thermal factors. The correlation coefficients between multi-factors regressed and observed PM_2.5 concentrations pass the 95% confidence test, and are higher than that of single-factor regression over most regions. The observed data from December 2016 to February 2017 were chosen to test the regression equation. The test result reveals that the regression equation is effective for predicting PM_2.5 concentrations over regions with high primary emission.  相似文献   

Cascade optimization design of inter-satellite link enhanced with adaptability in future GNSS satellite networks     

Jinhui Huang  Wenxiang Liu  Yingxue Su  Feixue Wang 《GPS Solutions》2018,22(2):44

Inter-satellite communication and inter-satellite ranging are the foundation of autonomous navigation for satellite navigation systems. Due to cost limitations, it has been proposed in recent years to equip each satellite with one spot beam antenna, which points to different satellites according to a polling mechanism, resulting in an intermittently connected satellite network. This poses the problem of how to design the inter-satellite link (ISL) contact plan, which determines the evolution of network topology and has important effects on system performance. We propose a new framework for the ISL contact plan design in satellite navigation systems. Considering contact plan design as a multi-parameter and multi-objective optimization problem, the cascade optimization design (COD) is proposed as a method simple to implement and optimize the parameters of the contact plan. COD considers network load and geometry of satellites and has a good adaptability. In the proposed framework, both communication and measurement requirements are taken into account while the contact sequence and the slot length are optimized in two steps. Simulation results show that COD guarantees zero packet drops and achieves the least average delay with a selected network load. When the packet arrival rate is 0.45 packets/s, the packet drop ratio of COD is zero, while that of the traditional simulated annealing design (SAD) is 2.58%. The delay of COD is 22.97 s, which is only two-fifth of the SAD value of 58.77 s. At the same time, using COD the average autonomous navigation weighted dilution of precision decreases from 1.4408 to 0.9671. COD also has strong robustness and performance regardless of the onboard buffer size.  相似文献   

Research on eco-environmental vulnerability evaluation of the Anning River Basin in the upper reaches of the Yangtze River     

Huaiyong Shao  Meng Liu  Qiufang Shao  Xiaofei Sun  Jinhui Wu  Zhiying Xiang  Wunian Yang 《Environmental Earth Sciences》2014,72(5):1555-1568

The Anning River Basin is located in the transitional zone of the Qinghai-Tibet Plateau, Yunnan-Kweichow Plateau and Sichuan Basin. This transitional zone is an important ecological barrier of the upper reaches of the Yangtze River and plays a significant role in the ecological security and ecological construction of Sichuan Province. However, the innate vulnerability of the eco-environment combined with the unreasonable development and use of minerals, hydropower, agriculture and animal husbandry resources contribute to prominent eco-environmental problems. In support of remote sensing and geographical information system, this study uses the spatial principal component analysis (SPCA) method to build the evaluation model for the vulnerability evaluation and analysis of the eco-environment in the Anning River Basin. The following indicators are selected for the SPCA: elevation, slope, vegetation index, land use, soil type, soil erosion, precipitation, temperature, and population density. Thereafter, the first four principal components are selected and their corresponding weights are determined. The eco-environmental vulnerability comprehensive index of the Anning River Basin is calculated by using these data. According to the calculated results, the eco-environmental vulnerability of the Anning River Basin is divided into five levels, namely, potential vulnerability, slight vulnerability, light vulnerability, moderate vulnerability, and high vulnerability. Eco-environmental changes for the past 20 years (from 1990 to 2010) are discussed and analyzed as well as the driving forces. The analysis shows that the eco-environmental vulnerability of the Anning River Basin is at the moderate level, and exhibits obvious vertical distribution characteristics. The main reasons that cause eco-environmental changes are mainly human factors, socioeconomic factors, and environmental protection policies like “Natural Forests Protection” and “Grain-for-Green”. Based on the vulnerability classification results, the Anning River Basin is divided into three partitions for different degrees of eco-environmental reconstruction and protection, which provides foundation for the local eco-environmental reconstruction so as to reconstruct in order of the importance and urgency.  相似文献   

Petrogenesis of the Yangchang Mo‐bearing granite in the Xilamulun metallogenic belt,NE China: geochemistry,zircon U–Pb ages and Sr–Nd–Pb isotopes     

Qingdong Zeng  Jinhui Yang  Zuolun Zhang  Jianming Liu  Xiaoxia Duan 《Geological Journal》2014,49(1):1-14

The Yangchang granite‐hosted Mo deposit is typical of the Xilamulun metallogenic belt, which is one of the important Mo–Pb–Zn–Ag producers in China. A combination of major and trace element, Sr, Nd and Pb isotope, and zircon U–Pb age data are reported for the Yangchang batholith to constrain its petrogenesis and Mo mineralization. Zircon LA‐ICPMS U–Pb dating yields mean ages of 138 ± 2 and 132 ± 2 Ma for monzogranite and granite porphyry, respectively. The monzogranites and granite porphyries are calc‐alkaline with K₂O/Na₂O ratios of 0.75–0.92 and 1.75–4.42, respectively. They are all enriched in large‐ion lithophile elements (LILEs) and depleted in high‐field‐strength elements (HFSEs) with negative Nb and Ta anomalies in primitive‐mantle‐normalized trace element diagrams. The monzogranites have relatively high Sr (380–499 ppm) and Y (14–18 ppm) concentrations, and the granite porphyries have lower Sr (31–71 ppm) and Y (5–11 ppm) concentrations than those of monzogranites. The monzogranites and granite porphyries have relatively low initial Sr isotope ratios of 0.704573–0.705627 and 0.704281, respectively, and similar ²⁰⁶Pb/²⁰⁴Pb ratios of 18.75–18.98 and 18.48–18.71, respectively. In contrast, the ε_Nd(t) value (−3.7) of granite porphyry is lower than those of monzogranites (−1.5 to −2.7) with Nd model ages of about 1.0 Ga. These geochemical features suggest that the monzogranite and granite porphyries were derived from juvenile crustal rocks related to subduction of the Paleo‐Pacific plate under east China. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

航空重力向下延拓分组修正的正则化解法     

顾勇为  归庆明  韩松辉  王靳辉 《武汉大学学报(信息科学版)》2013,38(6):720-724

在航空重力向下延拓中,针对病态性对解算结果各个部分影响的不同进行分组修正,提出了分组修正的正则化解法。利用信噪比评估病态性影响,得到将参数分组的方式;依分组修正思想构造正则化矩阵;通过极小化均方误差选取正则化参数。基于EGM2008重力场模型仿真一组航空重力数据,验证了该方法对航空重力数据向下延拓过程的有效性,并与另外3种方法作比较。结果表明,新方法具有更高的精度。  相似文献