新型质子旋进磁力仪软件系统设计与实现   总被引：1，自引：1，他引：0  

严兴  柴剑勇  黄晖  黎珠博  晓英 《华南地震》2009,29(4):95-102

针对自主研制的新型质子旋进磁力仪的硬件系统的技术特点,结合具体测量中的一些实际情况,基于Microchip公司的P1C16F877A芯片,设计并实现了一套测控软件;系统的介绍了该软件系统各个模块的设计原理与程序流程,分析了其技术特点与优势.并在测量大地总场值的实验中,与加拿大GEM公司生产的DiDd三分量磁力仪测量进行了比较,结果表明我们的新型质子旋进磁力仪在测量精度与准确度上接近DiDd三分量磁力仪,而在成本仪器体积与重量方面,则明显优于DiDd.  相似文献   

地电观测系统的干扰分析与故障排除方法     

朱振家  田洁  刘鸿斌  丁宏  朱宗德 《地震地磁观测与研究》2009,30(6):100-103

地电观测由测量区、外线路和观测仪器及辅助设备组成。观测系统容易受到外界干扰,而且故障较多,笔者根据多年的实践经验,对常见的干扰及故障现象进行了分析研究。结果表明：地电观测对区域的观测环境变化以及细微电磁环境和观测系统的变化都有非常灵敏的反应。  相似文献   

Hack＇s law of debris-flow basins     

LI Yong YUE Z. Q. LEE C. F BEIGHLEY R. E. CHEN Xiao-Qing HU Kai-Heng CUI Peng 《国际泥沙研究》2009,24(1):74-87

Hack＇s law was originally derived from basin statistics for varied spatial scales and regions. The exponent value of the law has been shown to vary between 0.47 and 0.70, causing uncertainty in its application. This paper focuses on the emergence of Hack＇s law from debris-flow basins in China. Over 5,000 debris-flow basins in different regions of China with drainage areas less than 100km^2 are included in this study. Basins in the different regions are found to present similar distributions. Hack＇s law is derived from maximum probability and conditional distributions, suggesting that the law should describe some critical state of basin evolution. Results suggest the exponent value is approximately 0,5. Further analysis indicates that Hack＇s law is related to other scaling laws underlying the evolution of a basin and that the exponent is not dependent on basin shape but rather on the evolutionary stage. A case study of a well known debris-flow basin further confirms Hack＇s law and its implications in basin evolution.  相似文献   

带先验知识的波阻抗反演正则化方法研究   总被引：6，自引：2，他引：4       下载免费PDF全文

崔岩  王彦飞  杨长春 《地球物理学报》2009,52(8):2135-2141

针对波阻抗反演中存在的不适定性问题,本文提出了一种带先验知识的正则化重开始共轭梯度法.该方法的内层循环采用修改的共轭梯度法,并使用重开始技巧;外层循环使用Morozov偏差准则作为停机准则.正则参数的选取采用连续几何选取法.克服了传统共轭梯度法迭代不足或迭代过度的缺点,将迭代步数控制在了合适的范围,使算法能够更快速更准确的收敛.同时考虑了用最速下降法计算先验解和对解施加非均一的规范约束.通过理论模型试算和实际资料处理,并与共轭梯度法进行对比,表明该算法具有精度高、抗病态能力强,运算速度快的优点,具有实用性.  相似文献   

Physical constraints on c13 and δ for transversely isotropic hydrocarbon source rocks          下载免费PDF全文

Fuyong Yan  De‐Hua Han  Qiuliang Yao 《Geophysical Prospecting》2016,64(6):1524-1536

Based on the theory of anisotropic elasticity and observation of static mechanic measurement of transversely isotropic hydrocarbon source rocks or rock‐like materials, we reasoned that one of the three principal Poisson's ratios of transversely isotropic hydrocarbon source rocks should always be greater than the other two and they should be generally positive. From these relations, we derived tight physical constraints on c₁₃, Thomsen parameter δ, and anellipticity parameter η. Some of the published data from laboratory velocity anisotropy measurement are lying outside of the constraints. We analysed that they are primarily caused by substantial uncertainty associated with the oblique velocity measurement. These physical constraints will be useful for our understanding of Thomsen parameter δ, data quality checking, and predicting δ from measurements perpendicular and parallel to the symmetrical axis of transversely isotropic medium. The physical constraints should also have potential application in anisotropic seismic data processing.  相似文献   

Rossby wave Green’s functions in an azimuthal wind     

G. M. Webb  C. T. Duba  Q. Hu 《地球物理与天体物理流体动力学》2016,110(3):224-258

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长牡蛎外套膜组织着色区和无色区的微生物多样性比较分析     

谢超伊  宋宏策  董美云  张钰煊  高凯利  魏磊  王晓通 《海洋通报》2024,(2):188-197

典型的开管式软体动物长牡蛎（Crassostrea gigas）具有开闭壳的行为习惯,易使大量海水成分进入体内。因此,海水中的微生物极易附着于长牡蛎的软体部表面。本研究利用16S rRNA对长牡蛎外套膜着色区和无色区以及其生活区域海水进行了微生物多样性比较分析。结果显示：长牡蛎外套膜表面的微生物多样性与丰富度均高于海水。在门水平上,变形菌门（Proteobacteria）为长牡蛎外套膜着色区与无色区的共同优势菌类,而海水中优势菌类为拟杆菌门（Bacteroidetes）。在属水平上,主要发现了弧菌（Vibrio）、假交替单孢菌（Pseudoalteromonas）和海洋单胞菌（Marinomonas）在内的28个菌属。此外,线性判别分析（Linear discriminant analysis effect size,LeFSe）显示,外套膜着色区与无色区的微生物标志物存在差异。着色区的主要标志物为螺旋体科未分类属（norank＿f＿Spirochaetaceae）,而无色区的主要标志物为弧菌（Vibrio）。综上,长牡蛎外套膜组织表面与海水之间的微生物组成存在较大差异。尽管外套膜着色...  相似文献   

Scale dependent dynamic capillary pressure effect for two-phase flow in porous media     

《Advances in water resources》2014

Causes and effects of non-uniqueness in capillary pressure and saturation (P^c–S) relationship in porous media are of considerable concern to researchers of two-phase flow. In particular, a significant amounts of discussion have been generated regarding a parameter termed as dynamic coefficient (τ) which has been proposed for inclusion in the functional dependence of P^c–S relationship to quantify dynamic P^c and its relation with time derivative of saturation. While the dependence of the coefficient on fluid and porous media properties is less controversial, its relation to domain scale appears to be dependent on artefacts of experiments, mathematical models and the intra-domain averaging techniques. In an attempt to establish the reality of the scale dependency of the τ–S relationships, we carry out a series of well-defined laboratory experiments to determine τ–S relationships using three different sizes of cylindrical porous domains of silica sand. In this paper, we present our findings on the scale dependence of τ and its relation to high viscosity ratio (μ_r) silicone oil–water system, where μ_r is defined as the viscosity of non-wetting phase over that of the wetting phase. An order of magnitude increase in the value of τ was observed across various μ_r and domain scales. Also, an order of magnitude increase in τ is observed when τ at the top and the bottom sections in a domain are compared. Viscosity ratio and domain scales are found to have similar effects on the trend in τ–S relationship. We carry out a dimensional analysis of τ which shows how different variables, e.g., dimensionless τ and dimensionless domain volume (scale), may be correlated and provides a means to determine the influences of relevant variables on τ. A scaling relationship for τ was derived from the dimensionless analysis which was then validated against independent literature data. This showed that the τ–S relationships obtained from the literature and the scaling relationship match reasonably well.  相似文献   

张衡地动仪(2)：史料和考证     

冯锐 《中国地震研究》2014,28(1):12-21

Historical data regarding Zhang Heng＇s seismoscope is not singular proof. Actually, the four earliest historical documents, i. e. , Continuation of Historiography of Han Dynasty, Historiography of the Later Han, Book of the Later Han and Ding Record all have relevant records of its structure, size, principle, response to earthquake and actual applications. These five aspects are supported by archaeological research, unearthed cultural relics, historical earthquakes and modern seismological study. These historical materials contain a great deal of specific information about this ancient seismoscope. In conclusion, the authenticity and reliability of Zhang Heng＇s seismoscope are verified.  相似文献   

基于GRACE Follow-On卫星重力梯度法精确反演地球重力场   总被引：2，自引：1，他引：1       下载免费PDF全文

郑伟  许厚泽  钟敏  员美娟 《地球物理学报》2014,57(5):1415-1423

由于GRACE Follow-On双星系统等效于基线长为星间距离的一维水平重力梯度仪,因此本文基于GRACE Follow-On卫星重力梯度法开展了精确和快速反演下一代地球重力场的可行性论证研究. 研究结果表明：第一,基于GRACE Follow-On卫星重力梯度法（GFO-SGGM）,利用卫星轨道参数（轨道高度250 km、星间距离50 km、轨道倾角89°、轨道离心率0.001）、关键载荷测量精度（星间距离10^-6 m、星间速度10^-7 m·s^-1、星间加速度10^-10 m·s^-2、轨道位置10^-3 m、轨道速度10^-6 m·s^-1、非保守力10^-11 m·s^-2）、观测时间30天和采样间隔10 s反演了120阶地球重力场,在120阶处累计大地水准面精度为9.331×10^-4 m. 第二,在120阶内,利用将来GRACE Follow-On双星反演地球重力场精度较现有GRACE双星平均提高61倍,因此GRACE Follow-On卫星重力梯度法是进一步提高地球重力场反演精度的优选方法. 第三,下一代GRACE Follow-On计划较当前GRACE计划的优点如下：轨道高度更低（200~300 km）、载荷精度更高（10^-7 ~10^-9 m·s^-1）和星间距离更短（50~100 km）.  相似文献