Some results of modeling D-D seismogenic pattern by the fracture model experiment of large-scale rock samples (I)     

Yang-Quan Lu  Jia-Liu Zhao  Jia-Dong Qian  Yu-Xiang Wang  Jian-Yi Liu 《地震学报(英文版)》1998,11(2):229-236

Using the natural limestone samples taken from the field with dimension of 500 mm×500 mm×1 000 mm, the D-D (dilatancy-diffusion) seismogeny pattern was modeled under the condition of water injection, which observes the time-space evolutionary features about the relative physics fields of the loaded samples from deformation, formation of microcracks to the occurrence of main rupture. The results of observed apparent resistivity show: 1 The process of the deformation from microcrack to main rupture on the loaded rock sample could be characterized by the precursory spatial-temporal changes in the observation of apparent resistivity; 2 The precursory temporal changes of observation in apparent resistivity could be divided into several stages, and its spatial distribution shows the difference in different parts of the rock sample; 3 Before the main rupture of the rock sample the obvious “tendency anomaly” and “short-term anomaly” were observed, and some of them could be likely considered as the “impending earthquake” anomaly precursor of apparent resistivity. The changes and distribution features of apparent resistivity show that they are intrinsically related to the dilatancy phenomenon of the loaded rock sample. Finally, this paper discusses the mechanism of resistivity change of loaded rock sample theoretically. This subject is supported by the key project during the 8-th “Five Year Plan” from the State Science and Technology Commission of China (85-04-04).  相似文献   

广西英罗湾红树林表土沉积的孢粉学研究   总被引：1，自引：0，他引：1  

王开发  张玉兰 《沉积学报》1998,16(3):31-37

对广西英罗湾红树林的木榄（Ｂｒｕｇｕｉｅｒａｇｙｍｎｏｒｈｉｚａ）、秋茄（Ｋａｎｄｅｌｉａｃａｎｄｅｌ）、红海榄（Ｒｈｉｚｏｐｈｏｒａｓｔｙ－ｌｏｓａ）、桐花树（Ａｅｇｉｃｅｒａｓｃｏｎｎｉｃｕｌａｔｕｍ）、海漆（Ｅｘｃｏｅｃａｒｉａａｇａｌｏｃｈａ）五个群落表土孢粉样品进行系统的分析,研究结果表明：（１）红树林表土孢粉能正确反映其植被组成,红树类孢粉在组合中占４０％～７０％左右,但不同群落其比例略有差异,秋茄群落最高,达总数４８％～７７．３％,桐花树群落略低,为３９．７５％～４６．２％,高潮线堤岸的海漆群落最低,仅为１３．８％～３７．８％;（２）在红树林表土孢粉组合中,红树类花粉比例从群落中心向群落内外侧减低,不同群落亦有差异;（３）红树林表土孢粉组合混有一定的外来种类,其动力因素为风的吹扬和流水搬运,外来孢粉以松最多,其次为水龙骨科等孢子,草本花粉最少;（４）红树林孢粉组合能很好指示其生态环境,反映热带季风海洋气候,温度、降水、含盐度、有机质含量等,指示年均气温２１～２５℃、降水量１４００～２０００ｍｍ,土壤含盐度４．６％～２７．８％,有机质３％～５％的生态环境。  相似文献   

Estimating work-magnitude associations in earth surface processes     

W. E. Bardsley  M. M. Khatep 《Mathematical Geology》1991,23(4):591-608

Magnitude-frequency concepts in earth surface processes have found widespread application following the publication of the well-known paper Wolman and Miller. Of particular interest in such studies is the determination of those event magnitudes which make the most important long-term contributions to the total work of a given process. However, there has been little discussion to date concerning an appropriate estimator of the parameter , where is the long-term work achieved by events within a specified magnitude range, expressed as a proportion of the long-term work achieved by events of all magnitudes. The estimation of is straightforward for the time-independent case where short-duration events occur randomly in time, and event magnitudes are independent random variables from a common distribution. For this model, exists as a true parameter which can be estimated by , where is the sample proportion of work contributed by events within the specified magnitude range. This estimator is biased, but it is almost median-unbiased for large samples. An approximate expression for var ( ) can be obtained from standard results. A similar approach to the estimation of can be applied to estimating the long-term work contribution of the largest events in consecutiveR-year periods. An example is presented using riverbank erosion data. Within the constraints of the time-independent model, the estimation procedure is quite general and can be applied with or without prior specification of the probability distribution of event magnitudes. In some situations, estimation can also be achieved indirectly by using a sample of the causal events which generate the individual work events. This indirect estimation is particularly simple if work magnitude is a power transformation of causal magnitude, and the distribution of causal event magnitudes can be approximated by a lognormal distribution or a Weibull distribution. The relative work achieved by events within ever-smaller magnitude ranges leads in the limit to the work intensity function,P(y). A plot of this function shows the relative importance ofy—magnitude events with respect to their long-term work contributions. Estimation ofP(y) is carried out by first fitting a probability distribution to a sample of event magnitude data. The functionP(y) is unimodal with respect to the following probability distributions of event magnitudes: lognormal, Weibull, unimodal beta, gamma, and inverse Gaussian. A lognormal distribution of event magnitudes produces the maximum work intensity at the lognormal median. In a strict mathematical sense, the long-term work contribution of very large and very small events is insignificant. However, little can be deduced concerning the pattern of work intensity between these two extremes. In particular, there appears no reason to suppose that the maximum work intensity will coincide with work magnitudes classified as intermediate.  相似文献   

海洋生物样品中硒的氢化物发生-原子荧光分析(HG-AFS)   总被引：2，自引：0，他引：2  

张朝辉 《中国海洋大学学报(自然科学版)》2001,31(3):375-381

采用硼氢化钠还原法将试样中硒还原为挥发性硒化氢 ,氩为载气将硒化氢吹出并导入火焰原子化器进行原子荧光测定。以正交设计法对该还原反应、氢化物转移、原子化及原子荧光测定条件等进行了详细研究。实验结果表明 ,在佳化条件下 ,该法检出限为 0 .0 72μ g/ dm3,相对标准偏差为 2 .0 %。标准曲线表明 ,在 0 .0 0 0～ 1.0 0 0μ g/ dm3Se浓度范围内 ,有理想的线性关系。本法测定海洋生物样品硒的回收率为 95.8%～ 10 2 .4 %。  相似文献   

一种移动式海水痕量元素洁净采集实验室的设计     

倪佐涛  刁新源  张宗兵  丛石磊  孙毅  陈钊 《海洋科学》2020,44(6):137-140

痕量元素及其同位素采集、预处理和分析在海洋研究中具有重要的作用，由于含量极低，在采样、样品预处理及分析过程中容易受到外界污染源沾污。通过在一个20尺标准超高集装箱内制作一套移动式海水痕量元素洁净采集实验室，完成对实验室空间设计、空气质量控制，样品快速转移，实现水样上船后快速进入到洁净环境中，减少样品暴露在大气中时间，在洁净环境中高效完成样品取样、过滤和预处理等操作。所有操作满足GEOTRACES组织有关痕量元素采集的规范要求，从源头上保证分析测试结果的可靠性。  相似文献   

泉州湾、围头湾翡翠贻贝海区半人工采苗技术研究     

陈木  许万竹  王聪明  吴立峰  方少华  李丕廉  苏维迎  王贵台  黄建立 《海洋科学集刊》1997,(39):51-57

本文对泉州湾和围头湾翡翠贻贝的生殖腺性状、繁殖期、幼虫数量分布、附苗期及海区半人工采苗技术进行了研究。两湾翡翠贻贝繁殖期为5-9月,5月中旬至6月中旬为繁殖盛期,主要的附苗季节在6月中旬和7月上旬。选用胶胎绳和棕绳为采苗器,附苗效果较好;并讨论了投挂采苗器的适宜时间。  相似文献   

灰色关联度概念在地质判别分析中的应用     

孙效功  杨作升  李学伦 《中国海洋大学学报(自然科学版)》1994,(Z3)

将灰色系统理论中关联度的概念应用于地质判别分析，得到一种新的判别分析方法──灰色判别分析。该方法的基本思想是通过计算未知样品与多组已知样品间的关联度大小来实现样品的分类。经地质学的实例计算表明，该方法切实可行。  相似文献   

Z-2000偏振塞曼石墨炉原子吸收分光光度计测定地球化学样品中痕量金   总被引：5，自引：2，他引：3  

李勇 《岩矿测试》2008,27(4):305-309

用φ=50%的王水分解样品,聚氨酯泡沫塑料吸附富集金,10g/L硫脲为解脱剂,偏振塞曼石墨炉原子吸收分光光度计测定痕量金。对干燥、灰化、原子化、净化温度和时间,以及载气流量和灯电流强度进行了讨论;对影响金吸附效果的泡塑载体和王水浓度等因素进行了研究。通过实验得到了Z-2000偏振塞曼原子吸收分光光度计最佳石墨炉分析测试条件。方法检出限为0.3ng/g,回收率为95.0%~101.0%,精密度(RSD,n=12)低于8.0%,经国家一级标准物质(GBW07243~GBW07245)分析验证,结果与标准值相符。  相似文献   

铜试金预富集-辉光放电质谱法测定贵金属矿样中痕量铂钯铱金   总被引：4，自引：2，他引：2  

陈丁文  李斌  董守安  普朝光 《岩矿测试》2008,27(5):329-332

对利用铜试金预富集后辉光放电质谱法(GDMS)测定贵金属矿样中痕量Pt、Pd、Ir、Au的方法进行了探索性研究。着重考察了铜试金条件的选择和辉光放电电极的匹配、质谱的测定条件和测定方法等。分析结果表明,痕量(μg级)贵金属元素Pt的含量在1.99~15.0μg,回收率为92.0%~111.9%;Pd的含量在3.15~29.78μg,回收率为88.4%~113.3%;Ir的含量在0.12~0.60μg,回收率为68.3%~100.0%;Au的含量在10.43~24.08μg,回收率为98.9%~127.0%。方法可应用于矿石、矿物及其他物料中痕量贵金属的分析。  相似文献   

车载LiDAR场景中路灯的提取与识别     

张西童  刘会云  李永强  黄腾达  李有鹏 《测绘工程》2016,25(9):50-54

为解决车载LiDAR城市场景中路灯提取和识别问题,文中提出基于样本的路灯提取算法。先通过人机交互的方式提取路灯的样本参数;再依据数学形态学闭运算提取点云场景中疑似路灯的位置,根据样本参数确定疑似路灯范围并提取疑似路灯点云;然后进行路灯样本和疑似路灯点云的匹配;最后,通过建立路灯样本缓冲区实现路灯判断和提取。通过试验验证,算法不仅可以快速自动提取路灯点云,还能完成路灯单一种类的识别。  相似文献