基桩倾斜弹性波检测机理     

邓业灿  林维芳  李毅臻  雷卓翰  黄汉平 《物探与化探》2007,31(2):186-188

阐述了基桩倾斜无损检测基本原理——惠更斯-菲涅尔原理。通过在桩侧面实施地震排列装置检测试验，证实了桩倾斜度越大，桩侧效应越强。在倾斜基桩中埋设三分量检波器检测结果说明，基桩倾斜时，桩侧界面响应主要以转换后沿界面方向的纵波与垂直于桩侧面的横波为主。  相似文献   

玲珑金矿田岩石地球化学测量及其找矿效果   总被引：1，自引：1，他引：0  

张德宏  张庆禧 《山东国土资源》1998,(1)

根据玲珑金矿田１∶２０００岩石地球化学测量结果,结合本区地质构造条件,初步总结了该矿田岩石地球化学特征。获取的岩石地球化学异常经过验证,施工的３５个钻孔有２７个见矿,４３条验证探槽中有４条发现工业矿体。该方法在发现隐伏的矿化蚀变带、寻找矿体（矿化体）、确定矿体剥蚀程度及指导钻探施工等方面均有明显效果。  相似文献   

龙泉金矿流体包裹体中原生气体与金矿远景评价     

伍刚  张文淮  栗春芳 《地质科技情报》1998,(Z1)

龙泉金矿研究表明,石英中流体包裹体的均一温度、盐度及原生气体的含量和变化,可以作为金矿找矿、评价的微观地质依据。流体包裹体是成矿流体的代表,能反映金矿的形成环境及流体性质;可将均一温度和盐度作为远景评价的指标;原生气体是成矿流体重要的组成部分,其组分及含量,可以反映成矿流体的来源,同时,也是远景评价的重要参数;该区流体包裹体中ＣＨ４,ＣＯ２,Ｏ２,Ｈ２及Ｈ２Ｏ是金矿化的重要指示性原生气体。  相似文献   

双三次数值模式与理想Lamb波、龙卷扰动对比模拟分析     

辜旭赞  张兵 《气象科技》2007,35(5):613-620

通过"双三次曲面拟合—时间步长积分—双三次曲面拟合……",实现成为一种双三次曲面拟合新算法数值模式。它对模式大气作非线性(空间二阶可导)描述,是用数值分析(三次样条/双三次曲面)与计算方法近似求解大气运动非线性偏微分方程组。用Z坐标系高分辨率双三次数值模式,采用原始大气运动方程组和采用欧拉时间积分方案,设置理想扰动,对大气声波Lamb波做数值模拟;采用大气不可压假定,除去声波,对大气重力波龙卷扰动做数值模拟。对比模拟发现:理想Lamb波以声速在水平方向传播,扰动能量频散快,仅能在原地持续数秒钟;理想龙卷扰动则在原地可持续约1 min,且波动内圈(外圈)自下至上始终处于风场辐合(辐散)状态,具冷心结构和气压驻波特征,可因水汽进入扰动与借助凝结潜热释放而得到发展。  相似文献   

Evolution of isotopic compositions in groundwater of the area between the Gulf of Oman and the Arabian Gulf     

Ahmed Murad 《中国地球化学学报》2010,29(2):152-156

The stable isotopes of oxygen and hydrogen have been implemented to assess the recharge mechanisms in an area in the UAE bounded to the northwestern part of the Gulf of Oman and the southeastern part of the Arabian Gulf. The conversion of stable isotopes to deuterium excess was utilized as a supportive tool to understand the process of groundwater recharge. The concluding results of this study showed that the origin of moisture is the Mediterranean Sea. The precipitation is the main source of recharge, in which the precipitation having undergone evaporation before recharge occurs. The comparison between regression line for data collected in 1996 and regression line for samples collected in 2006 suggests that the precipitation water which recharged the groundwater, was diluted with groundwater and this dilution is observed from decreasing of the deuterium excess of collected groundwater samples with increasing isotopes of oxygen. The dilution of groundwater with the recharge water suggests modern-day recharge as it is seen from high deuterium excess that exceeded the deuterium excess of LMWL and was close to MMWL.  相似文献   

新疆东天山红石金矿床原生晕特征与矿体叠加模型     

王世新  杨毅恒 《世界地质》2010,29(3):383-391

红石金矿床是新疆东天山康古尔塔格金矿带中的代表性矿床之一。通过对其地表、已开采中段及部分钻孔的岩石系统采样分析和计算统计,研究了各指示元素在不同位置的组合特征。结果表明:指示元素中Au、Ag密切相关,其他元素组合复杂多变,反映了成矿成晕的多期性、多阶段特点。结合实际勘查资料,采用多种计算方法,建立了矿床原生晕轴向分带模式,即矿床轴向分带(自上而下)为Bi-Mo-Hg-Zn-Pb-Ag-As-Cu-Sb-Au。利用不同中段的7个分带评价值指标确定了矿体的叠加模型。  相似文献   

地震纵波技术预测煤层瓦斯富集区的探讨与实践     

常锁亮  刘洋  赵长春  李国发  陈强 《中国煤炭地质》2010,(8):9-15

基于国内外煤层瓦斯富集的岩石物理及地球物理响应的研究成果,提出了以煤层反射波振幅、频率及衰减等动力学特征变化为主要研究对象的地震纵波预测技术方案;探讨了利用叠后Gamma拟合声波约束反演、频谱分解属性分析和叠前AVO反演、弹性阻抗反演等纵波技术预测煤层瓦斯富集性的理论依据及实现方法。上述技术在沁水盆地进行了预测尝试,其获得的含气性预测成果与探井实测的瓦斯富集情况基本吻合,初步证明了上述纵波预测技术方法在开展煤层瓦斯富集区研究方面的可行性和有效性。  相似文献   

海洋透光率仪的设计及其在初级生产力研究中的应用*     

许占堂  施震  谢栢成  廖健祖  杨跃忠  周雯  李彩  杨顶田 《热带海洋学报》2022,41(3):38-45

海洋浮游植物光合作用固碳在全球碳循环中扮演着极为重要的角色, 获取不同光衰减对应的海水深度, 对于采集水样用于海洋初级生产力的研究具有重要意义。本研究于国际上首次开发了无缆便携式海洋透光率仪, 特殊的光学结构设计和光谱滤光技术使得光谱响应在波段400~700nm范围内超过了同类海洋传感器, 特定光衰减下对应的深度误差小于0.5m。将本设备应用于南海中尺度涡旋初级生产力的研究中, 在采样率和自动化方面验证了仪器的便携性; 通过对涡旋中初级生产力的空间分布规律进行分析, 检验了仪器数据结果的可靠性。海洋透光率仪在价格、准确性、可靠度和操作的便携性上具有不可比拟的优势, 将在未来海洋生态环境的研究中发挥重要作用。  相似文献   

Spatiotemporal variations of water use efficiency and its driving factors in Inner Mongolia from 2001 to 2020     

MEI Li  TONG Siqin  YIN Shan  BAO Yuhai  HUANG Xiaojun  ALATENG Tuya  WANG Yongfang  GUO Enliang  YUAN Zhihui  NASHUN Dalai  GAO Suriguga  LIU Xinyi  YE Zhigang 《地理学报(英文版)》2023,33(1):169-194

Water use efficiency (WUE) is an important variable to explore coupled relationships in carbon and water cycles. In this study, we first compared the spatial variations of annual gross primary productivity (GPP) and evapotranspiration (ET) using four GPP and ET products. Second, we selected the products closest to the flux towers data to estimate WUE. Finally, we quantitatively analyzed the impact of climate change and soil water content on WUE. The results showed that: (1) Four GPP and ET products provided good performance, with GOSIF-GPP and FLDAS-ET exhibiting a higher correlation and the smallest errors with the flux tower data. (2) The spatial pattern of WUE is consistent with that of GPP and ET, gradually decreasing from the northeast to the southwest. Higher WUE values appeared in the northeast forest ecosystem, and lower WUE values occurred in the western Gobi Desert, with a value of 0.28 gC m^?2 mm^?1. The GPP and ET products showed an increasing trend, while WUE showed a decreasing trend (55.15%) from 2001 to 2020. (3) The spatial relationship between WUE and driving factors reveal the variations in WUE of Inner Mongolia are mainly affected by soil moisture between 0 and 10 cm (SM0-10cm), vapor pressure deficit (VPD), and precipitation, respectively. (4) In arid regions, VPD and precipitation exhibit a major influence on WUE. An increase in VPD and precipitation has a negative and positive effect on WUE, with threshold values of approximately 0.36 kPa and 426 mm, respectively. (5) In humid regions, SM0-10cm, VPD, SM10-40cm, and SM40-100cm exert a significant impact on WUE, especially SM0-10cm, and weakens with increasing soil depths, these differences may be related to physiological structure and living characteristics of vegetation types in different climate regimes. Our results emphasize the importance of VPD and soil moisture in regional variability in WUE.  相似文献   

1961–2005年中国陆地生态系统净初级生产力模拟（英文）     

苑全治  吴绍洪  赵东升  戴尔阜  陈力  张磊 《地理学报(英文版)》2014,(1)

Net primary productivity(NPP) is the most important index that represents the structure and function of the ecosystem.NPP can be simulated by dynamic global vegetation models(DGVM),which are designed to represent vegetation dynamics relative to environmental change.This study simulated the NPP of China's ecosystems based on the DGVM Integrated Biosphere Simulator(IBIS) with data on climate,soil,and topography.The applicability of IBIS in the NPP simulation of China's terrestrial ecosystems was verified first.Comparison with other relevant studies indicates that the range and mean value of simulations are generally within the limits of observations;the overall pattern and total annual NPP are close to the simulations conducted with other models.The simulations are also close to the NPP estimations based on remote sensing.Validation proved that IBIS can be utilized in the large-scale simulation of NPP in China's natural ecosystem.We then simulated NPP with climate change data from 1961 to 2005,when warming was particularly striking.The following are the results of the simulation.(1) Total NPP varied from 3.61 GtC/yr to 4.24 GtC/yr in the past 45 years and exhibited minimal significant linear increase or decrease.(2) Regional differences in the increase or decrease in NPP were large but exhibited an insignificant overall linear trend.NPP declined in most parts of eastern and central China,especially in the Loess Plateau.(3) Similar to the fluctuation law of annual NPP,seasonal NPP also displayed an insignificant increase or decrease;the trend line was within the general level.(4) The regional differences in seasonal NPP changes were large.NPP declined in spring,summer,and autumn in the Loess Plateau but increased in most parts of the Tibetan Plateau.  相似文献