Triassic alkaline intrusives in the Yanliao-Yinshan area: their chronology, Sr, Nd and Pb isotopic characteristics and their implication   总被引：14，自引：0，他引：14  

Guohan Yan  Baolei Mu  Baoliang Xu  Guoqi He  Linkun Tan  Hui Zhao  Zhongfu He  Renhu Zhang  Guangsheng Qiao 《中国科学D辑(英文版)》1999,42(6):582-587

Dated isotopic ages for 15 alkaline intrusives in the Yanliao-Yinshan area, ranging from 268 to 190 Ma, ten of which are from 250 to 208 Ma, indicate that most of them were formed in the Triassic Epoch. All the E_Nd(t) ratios from - 17.19 to -3.21 averaging -7.09, the E_Sr(t) ratios fmm 11.7 to71.5 averaging 36.63, and the I_sr(t) ratios from 0.705 0 to 0.709 3 averaging 0.706 8, show their characteristics of enrichment. On the E_Nd (t) virus E_Sr(t) correlation diagram, the samples from these intmsives were plotted within the enriched mantle trend lines and just outside, demonstrating their close connection to materials from the enriched mantle reservoir, taking into account the same Pb isotopic composition as that of the mantle.  相似文献   

Anisotropy of ionospheric irregularities determined from the amplitude of satellite signals at a single receiver     

E. D. Tereshchenko  B. Z. Khudukon  M. O. Kozlova  T. Nygrén 《Annales Geophysicae》1999,17(4):508-518

A new method of determining the anisotropy parameters of small-scale irregularities in the ionospheric F region is presented and experimental results are shown. The method is based on observations of amplitude fluctuations of radio waves transmitted by satellites flying above the F region. In practice, Russian navigational satellites are used and both the amplitude and the phase of the signal is measured on the ground level. The method determines both the field-aligned anisotropy and the field-perpendicular anisotropy and orientation of the spatial spectrum of the irregularities, assuming that the contours of constant power have an elliptic shape. A possibility of applying the method to amplitude tomography is also discussed. Using a chain of receivers on the ground level, one could locate the regions of small-scale irregularities as well as determine their relative intensities. Then the large-scale background structures could be mapped simultaneously by means of ordinary ray tomography using the phase observations, and therefore the relations of small-scale and large-scale structures could be investigated.  相似文献   

A Study on the Distribution of Wave Phases     

John Z. YIM  Jaw-Guei LIN Associate Professor 《中国海洋工程》1999,(3)

Probability distributions of wave phases in association with distributions of surface elevations arestudied with wave records.Wave records of different nature are used for comparison.These are surface fluc-tuations acquired during wind wave flume experiments,representing wave generation under strong wind:andwave records measured in the northern part of Taiwan for waves in natural environments.Three probabilitymodels,the unifrom distribution,the beta distribution,and a model from Tayfun and Lo(1989)are adoptedto study the possible distributions of wave phases.It is found that when surface elevations become skewed,wave phases deviate from the usually assumed uniform distribution and a better model would be the beta dis-tribution.  相似文献   

North Brazil current: vertical structure     

N. P. Bulgakov  S. N. Bulgakov  V. N. Davydova  A. Z. Martinez 《Physical Oceanography》1999,10(2):107-121

On the basis of the data ofin situ measurements of the velocities of currents and basic hydrophysical parameters (such as temperature and salinity) carried out during Cruise 41 of the R/VAkademik Vernadsky, we analyze the structure of the North Brazil Current near the continental slope and in the equatorial abyssal part of the ocean in winter, establish the regularities of changes in the current velocity with depth, and compare the structures of the North Brazil and Guiana Currents. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

养鲍自污染水净化处理的初步研究     

谭烨辉  李江文  雷衍之 《热带海洋学报》1999,18(2):4P

用孔石莼变异株Ulvapertusa、活性炭纤维（ACF）和二氯异氰尿酸钠（NaDDT）对养殖皱纹盘鲍HaliotisdiscushannaiIno产生的自污染水进行净化,并用于饲养幼鲍。结果表明,孔石莼变异株能有效地吸收对幼鲍生长产生影响的水化因子──氨氮、亚硝酸盐,而活性炭纤维对污水中的COD_Mn和细菌的吸附率分别达82％和99．98％,经孔石莼变异株处理后的养鲍污水与未处理的养鲍污水对幼鲍生长影响明显不同。文中同时提出了用活性炭纤维、孔石莼变异株和二氯异氰尿酸钠净化养鲍污水的循环反馈投饵养殖模式。  相似文献   

以哈维氏弧菌(Vibrio harveyi)为重点的鱼类细菌病原的诊断与控制(英文)   总被引：2，自引：0，他引：2  

Ｂ．Ａｕｓｔｉｎ  Ｄ．Ａ．Ａｕｓｔｉｎ  Ｚ．Ｆａｒｈａｔ  Ｐ．Ａ．Ｗ．Ｒｏｂｅｒｔｓｏｎ 《中国海洋大学学报(自然科学版)》1999,(3)

作者对鱼类细菌病原的诊断与控制作了较全面的综述。细菌病原诊断技术包括酶联免疫吸附技术（ＥＬＩＳＡ）及蛋白印迹法（Ｗｅｓｔｅｒｎｂｌｏｔｉｎｇ）。细菌病原控制技术包括化学疗剂的应用,有益微生物的应用,营养添加剂,β－葡萄糖苷增强免疫抗病力,及免疫保护作用等。  相似文献   

一种合成2,2-二甲基-4-戊烯酸的方法     

钱佐国  孙明昆  李东慧  邹忠英 《中国海洋大学学报(自然科学版)》1999,(2)

报道一种合成２,２－二甲基－４－戊烯酸的新方法。由异丁醛与烯丙醇缩合得到２,２－二甲基－４－戊烯醛,后者经氧化银选择氧化生成２,２－二甲基－４－戊烯酸。此法氧化产率（９６％）高于分子氧氧化法（６１％）和歧化法（４１％）。反应中析出的金属银能定量回收,循环使用。  相似文献   

川西甲基卡地区西康群砂岩地球化学特征及对物源区、构造背景的指示     

周雄  周玉  谭洪旗  岳相元 《地质学报》2022,96(4):1380-1396

松潘-甘孜造山带中部大面积分布西康群浊积岩,为一套厚度巨大(2000～3000 m)的泥质碎屑复理石建造,以深海-次深海海底扇沉积为特征.本文通过对甲基卡稀有金属矿集区分布的西康群砂岩进行主量元素、微量元素及粒度分析,从而揭示该区砂岩构造背景和物源属性.研究结果表明,砂岩样品SiO2、CaO、MgO、Al2 O3、Fe...  相似文献   

甘孜-玉树断裂带晚第四纪走滑速率与滑动分解作用     

吕丽星  李传友  魏占玉  董金元  谭锡斌  石峰  苏鹏 《震灾防御技术》2017,12(3):456-468

滑动速率是研究断裂运动学特征、地震活动性和区域应变分配的重要参数和依据。前人关于甘孜-玉树断裂带滑动速率的研究结果存在较大差异,因此,其晚第四纪滑动速率有待进一步调查研究。本文基于卫星影像解译和野外实地考察,对甘孜-玉树断裂带西段（玉树断裂）上典型断错地貌点进行测量分析,得到玉树断裂晚第四纪走滑速率为6.6±0.1-7.4±1.2mm/a。通过与前人对甘孜-玉树断裂带东段（甘孜断裂）滑动速率的研究结果进行对比,发现甘孜-玉树断裂带东、西段滑动速率不一致,其原因是甘孜断裂的左旋滑移在向西传递的过程中,一部分应变被分配到了巴塘盆地南缘断裂上。巴塘盆地南缘断裂的存在很好地解释了玉树断裂的走滑速率比甘孜断裂偏低的原因。但是,从区域变形来看,巴塘盆地南缘断裂分配的滑动速率恰好说明了甘孜-玉树断裂带东、西段及鲜水河断裂带的水平构造变形是协调一致的。  相似文献   

Correlation between abnormal trends in the spontaneous fields of tectonic plates and strong seismicities          下载免费PDF全文

Da-Cheng Tan  Jian-Cun Xin 《地震科学（英文版）》2017,30(4):173-181

Tectonic activities, electrical structures, and electromagnetic environments are major factors that affect the stability of spontaneous fields. The method of correlating regional synchronization contrasts(CRSC) can determine the reliability of multi-site data trends or shortimpending anomalies. From 2008 to 2013, there were three strong earthquake cluster periods in the North–South seismic belt that lasted for 8–12 months. By applying the CRSC method to analyze the spontaneous field E_(SP) at 25 sites of the region in the past 6 years, it was discovered that for each strong earthquake cluster period, the E_(SP) strength of credible anomalous trends was present at minimum 30%of the stations. In the southern section of the Tan-Lu fault zone, the E_(SP) at four main geoelectric field stations showed significant anomalous trends after June 2015, which could be associated with the major earthquakes of the East China Sea waters(MS7.2) in November 2015 and Japan's Kyushu island(MS7.3) in April 2016.  相似文献