双相横向各向同性介质分界面上弹性波反射与透射问题研究   总被引：13，自引：5，他引：8  

刘洋  李承楚  牟永光 《地球物理学报》2000,43(5):691-698

从双相横向各向同性介质弹性波波动方程出发 ,利用边界上的 4个连续性条件 ,计算双相横向各向同性介质分界面上弹性波反射和透射系数 .计算表明 ,快纵波在双相横向各向同性介质分界面上 ,要产生反射快纵波、反射转换 qSV波、反射转换慢纵波和透射快纵波、透射转换qSV波、透射转换慢纵波 .反射转换慢纵波振幅和透射转换慢纵波振幅均较小 .频率、耗散和各向异性大小影响着快纵波反射系数的大小 .  相似文献   

广东气象短信系统体系结构简介     

李娜  郑延庆 《广西气象》2005,26(2):47-48

介绍广东气象短信三期系统平台的构建背景、体系结构和发送流程，为各省市气象短信平台建设提供参考。  相似文献   

OH-bearing planar defects in olivine produced by the breakdown of Ti-rich humite minerals from Dabie Shan (China)   总被引：2，自引：0，他引：2  

Jörg Hermann  John D. Fitz Gerald  Nadia Malaspina  Andrew J. Berry  Marco Scambelluri 《Contributions to Mineralogy and Petrology》2007,153(4):417-428

The partial breakdown of Ti-chondrodite and Ti-clinohumite during exhumation from ultra-high pressure to amphibolite facies conditions in garnet-pyroxenites from Dabie Shan (China) produces coronas of olivine coexisting with ilmenite blebs. Fourier transform infrared (FTIR) spectra of this newly formed olivine exhibit absorption bands in the hydroxyl-stretching region. Two intense peaks were observed at 3,564 and 3,394 cm⁻¹, identical in energy to peaks in Ti-clinohumite. Transmission electron microscopy (TEM) of the same olivine domains revealed the presence of a complex (001) planar intergrowth. These interlayers have a 1.35 nm repeat distance, which is characteristic of clinohumite. Such interlayers are also enriched in Ti with respect to the adjacent olivine as shown by energy dispersive spectrometry. The combined evidence from FTIR spectroscopy and TEM indicates that OH is incorporated along Ti-clinohumite planar defects. This study provides evidence that the nominally anhydrous phase olivine may contain OH as a humite-type defect beyond the breakdown of the hydrous humite minerals and confirms earlier suggestions that Ti plays a key role in OH incorporation in mantle olivine. We suggest that olivine containing Ti-clinohumite defects is an important phase for water transport in subduction zones and for the storage of water in cold subcontinental mantle. However, these defects are unlikely to be stable in hotter parts of the oceanic mantle such as where basaltic magmas are generated.  相似文献   

多震相层析成像与在介质中的多波型射线跟踪     

毛伟健  ＧｒａｈａｍＷ．Ｓｔｕａｒｔ 《CT理论与应用研究》1996,(4)

本文介绍了多震相的层析成像的思路和算法，通过穿透和反射走时可以同时作出２维和３维慢度（速度的倒数）重建。我们分析了在穿透和反射数据中确定速度和深度的不确定性，并认识到深度扰动对反射走时异常比慢度扰动更敏感。由不同波类型所提供的对速度和深度的约束，这个算法实际上减少了在一般反射层析成像在速度和深度之间的不确定性，并且也避免了在穿透层析成像中的不确定问题。线性化反演是通过从反射界面深度由分离速度参数迭代进行的。使用一个快速的２－Ｄ和３－Ｄ射线跟踪算法来计算穿透和反射走时和对幔度及反射界面深度的偏导数。深度和速度都用立方Ｂ样条函数来进行参数化。合成例子表明，当同时考虑穿透和反射时间，层析成像的结果得到改进。这个方法也应用到英国煤炭测量局（ＢｒｉｔｉｓｈＣｏａｌＭｅａｓｕｒｅｓ）沿跨线排列所记录的逆ＶＳＰ数据组。通过使用波形配合技术，用同时确定时间延迟和叠加权，可以自动拾取旅行时间。所观察到的逆ＶＳＰ层析成像可比周围介质具有较低速度的两个断层区域成像。断层的位置由附近的反射测线所确定。本文还讨论了在复杂２－Ｄ和３－Ｄ非均匀各向同性介质中地震射线跟踪方法。界面的几何形状和水平速度场都通过使用非均匀步长立方Ｂ－样条节点  相似文献   

太湖地区石英晶粒的某些超微构造及其成因意义          下载免费PDF全文

杨主恩  徐道一 《地质科学》1993,(2):161

 应用超高压电子显微镜对太湖及其附近的五通组石英岩中的石英晶粒进行研究,发现它们在自由位错密度、位错壁、亚晶粒和出熔构造等特征上存在着明显差别。据此推论,太湖和其附近地区的五通组石英岩曾遭受过不同的应力作用历史,太湖的标本曾受到高应力的瞬时高压影响。因此,太湖环形构造可能与小天体的撞击有关。  相似文献   

云—地闪电的传输线模式及回击电流速度   总被引：4，自引：1，他引：4  

陈明理  刘欣生 《高原气象》1995,14(4):385-395

利用Ｍａｘｗｅｌｌ‘ｓ方程组及回击产生的电磁辐射场的谱特征，给出了垂直于非完全导体地面之上的回击通道产生的地表电场垂直分量表达式，从而克服了由镜像法的不适用带来的误差。  相似文献   

透射槽波技术在煤田勘探中的应用研究     

张鑫  韩建光  牛云飞  徐世业  徐安全 《地质论评》2023,69(6):2023060013-2023060013

槽波地震勘探技术可以有效探查煤层中小断层、陷落柱等地质异常体,在探测精度和距离上明显优于其他煤矿井下勘探方法。透射法作为基本的槽波地震探测方法,具有简单灵活、探测范围大、准确率高等优势。采用透射槽波方法对实际煤矿工作面内断层构造进行探测研究,通过滤波、频散分析、波场及速度分析、能量分析以及透射CT成像等关键技术对实际透射槽波数据进行精细处理,获得准确的透射槽波成像剖面。根据槽波在煤层中受到断层阻断或遇到煤层破碎时其能量将急剧降低的特征,利用透射槽波能量CT剖面,并结合实际揭露情况,解释出12条可靠断层。通过实际煤层工作面透射槽波勘探方法测试,验证了透射槽波方法的有效性以及在煤田断层等构造探测中的实用价值。  相似文献   

A study by electron microscopy of gold and associated minerals from Round Mountain,Nevada     

《Ore Geology Reviews》2017

Details regarding the mineralization patterns of gold in epithermal systems are poorly understood. A refined understanding of gold microtextures, the interface between gold and associated minerals, and the role that nanoparticles play in gold mineralization could provide insight into the details of gold growth and may contain indicators of gold ore concentration mechanisms. Furthermore, a refined understanding of the interface also may explain variation in cyanide leaching extraction efficiency and may enable enhancement of recovery methods. Macrocrystalline gold samples from Round Mountain, Nevada were analyzed using field emission scanning electron microscopy and transmission electron microscopy. This study suggests that gold nanoparticles are common in Round Mountain gold and associated mineral phases, and may play an important role in the formation of macrocrystalline gold in this deposit. Microtopographic evidence indicates that the two dimensional nucleation and growth mechanism is dominant and nanotextural evidence suggests that nanoparticulate gold was the first stage of growth in the formation of these macrocrystalline samples that grew rapidly at high degrees of supersaturation. Results suggest that the interface between gold and quartz and other related minerals is far more complex than previously thought, and that textures present at the interface and in the bulk gold can help explain mineralization history and can also have implications for gold recovery efficiency for macrocrystalline bearing ore.  相似文献   

论稳定电流场的入射、反射、透射间的关系          下载免费PDF全文

傅平 《地球物理学报》1994,37(1):108-114

根据分界面上稳定电流场的边界条件，解稳定电流场Ｌａｐｌａｃｅ方程，给出椭球形分界面入射场、反射场及透射场的表达式，并导出圆柱形、球形分界面上入射角、反射角及透射角的关系式后，指出，只在少数特殊情况下三者才相等，对一般形状的大多数光滑连续分界面情况，它们是不相等的．其值取决于分界面的具体形状．  相似文献   

Al³⁺掺杂锂皂石的合成及其性能研究          下载免费PDF全文

王军  姚颖  孙进贺  马军  殷小杰  景燕 《盐湖研究》2012,20(1):29-33

采用水热法合成锂皂石,以LiCl-MgCl2-Na2SiO3-H2O为主要反应体系,加入NaOH调节反应体系的pH值,通过加入Al2(SO4)3.18H2O而引入Al3+进行掺杂改性,合成了系列锂皂石。对所得产物进行XRD检测,探测了产物的结晶化度和结构组成。通过分光光度计和流变仪测定了产物的透光性及粘度性能,结果发现反应体系pH值的变化可引起锂皂石产品水分散体系的透明度;控制一定的Al3+加入量,可得到具有较高粘度的锂皂石产品。  相似文献