荧光法在赤潮图像分析中的应用

赤潮藻样品中往往包含着各种复杂的非藻沉淀物,为解决这些微藻的探测和分析的问题,可以利用微藻类在一定波长的光照射下会产生荧光的特性,对裸甲藻等多种赤潮藻类进行荧光实验处理,并在此基础上对藻类的荧光图像和灰度图象进行图像分割,轮廓和纹理分析及图象识别等后继图象处理。实验证明,荧光法可以有效的去除背景噪声,保留藻类信息,使得后继的图象处理工作更加容易和有效,从而解决了探测和分析包含复杂背景的沉淀物样品中微藻的问题。     

楚雄盆地下侏罗统磨拉石楔沉积与含油性研究

楚雄盆地为一中生代周缘型走滑前陆盆地，通过对下侏罗统冯家河组沉积特征的详细研究与对比，作者认为早侏罗世是楚雄前陆盆地强烈坳陷与沉降的主要发展时期从早期到晚期经历了一个变深又变浅的典型前陆盆地充填过程。在前陆冲断块体的不断逆冲和加载条件下，楚雄盆地西部早侏罗世沉积物的来源主要为哀牢山造山带隆起，其沉积环境以滨，浅湖或湖泊三角洲为主。     

中国板块构造与盐类矿产

中国大陆的华北、塔里木、准噶尔－兴安、华南及甘青藏等五大板块发展过程中于地块边缘活动带、陆间裂谷、陆内裂谷等场所生成的含盐盆地，沉积了各时期（Ｏ、Ｃ、Ｔ、Ｊ－Ｅ和Ｑ）盐类矿床。通过分析对比认为，甘青藏板块兰坪－思茅拗陷带（Ｊ２－Ｅ１、Ｑ），塔里木板块（Ｃ、Ｋ－Ｅ、Ｑ），华北板块（Ｏ２），华南板块（Ｔ１－２）为成钾有利地带，中国东部众多的Ｋ－Ｅ红层盆地中成钾条件较差     

山西省部分台站下方S波速度结构研究及与地震关系探讨

本文利用山西省数字台网的深源远震S波记录,利用直接拟合S波波形的方法反演得到了山西境内山自皂(113.71,40.08)、右玉(112.37,40.02)、苛岚(111.72,38.78)、昔阳(113.72,37.57)、离石(111.24,37.53)、夏县(111.24,35.12)共6个台站下的剪切波速度结构.     

秦岭中段及其相邻区域S波速度结构研究

利用纯S波波形拟合方法,输入纯S波波形,使用传递矩阵计算了层状介质自底面传到地表约100 km厚度、32 s的理论地震波形;引进快速模拟退火法进行反演搜索理想模型,用理论波形与观测波形的相关系数作为约束函数,选择同一台站几个震例的理论波形与实际波形吻合最好的模型作为该台站下方的可接受速度结构模型.收集深源远震的清晰S波记录波形,我们共得到了陕西省境内秦岭造山带中段及其邻近区域13个地震台站下方的S波速度结构.结果显示,秦岭造山地带、渭河盆地及鄂尔多斯块体的地壳结构之间存在很大的差异,各个块体有其各自的构造特点;不过三个块体的地壳厚度都显示了由东向西逐渐增加的变化趋势.     

基于Matlab的水准点稳定性分析

通过使用Matlab功能强大的数学软件，应用于测量工程的数据处理。具体解决变形监测中水准点是否稳定的判定问题。并通过计算实例说明其可行性和优越性。     

Climatic response of thick leaf spruce (Picea crassifolia) tree-ring width at different elevations over Qilian Mountains, northwestern China

Tree-ring cores of thick leaf spruce (Picea crassifolia) taken from four sites at different elevations, in the middle of the Qilian Mountains, in the arid and semi-arid region of northwestern China, were used to develop four tree-ring width chronologies using standard dendrochronological methods. Results indicate that with increasing altitude the chronologies’ year-to-year variations decreased. Hence, the sensitivity of the tree-ring chronologies to climate decreases with altitude. Further analysis showed that the significant limiting factor on tree growth is spring precipitation. Measurements of stomata density and leaf dry weight suggest the species’ ecological adaptation strategy changes with elevation. At high elevation the metabolic rate of thick leaf spruce decreases, thus showing the effect of the climate.     

基于景观格局变化的海岸带生态风险评价——以辽宁省瓦房店市为例

文章利用RS和GIS技术手段对辽宁省瓦房店市1990—2015年的变迁过程进行监测,得出各历史时期的土地利用变化信息。将各类土地利用信息与景观生态学相结合,利用景观格局破碎度、景观分离度、景观优势度作为指标构建景观损失指数,并利用景观组分的面积比重构建海岸带生态风险指数。基于ArcGIS和Fragstats软件平台,通过空间采样和插值方法得到区域生态风险的空间分布,据此重构了瓦房店市1990—2015年的生态风险值变化过程。监测表明,1990—2015年期间,耕地、林地和滩涂呈减少趋势,水域和建设用地逐年增加,其他类型变化幅度不大。虽然耕地所占总面积比例由45.37%减少至37.23%,但一直是瓦房店最主要的景观。25年间瓦房店生态安全总体呈下降态势,1990—2015年6时段的生态风险年平均值分别为0.211 9、0.200 3、0.203 2、0.194 9、0.209 7和0.209 1。在时间维度,1990—2005年和2010—2015年生态安全度下降明显;在空间维度,瓦房店市海岸带的李官镇-三台满族乡和谢屯镇-炮台镇的生态风险度高,西杨乡、东岗镇和驼山乡生态风险由极高降为高或中,生态安全度有所提高。研究表明,人口和社会经济发展是影响瓦房店市景观格局变化的主要因素,该区域未来海岸带要实现可持续开发必须要进行科学的规划。     

高阶边界元方法求解规则波在三维局部渗透海床上的传播

基于线性势流理论,利用高阶边界元法研究了规则波在三维局部渗透海床上的传播。根据Darcy渗透定律推导出渗透海床的控制方程,利用渗透海床顶部和海底处法向速度和压强连续条件得到渗透海床顶部满足的边界条件。根据绕射理论,利用满足自由水面条件的格林函数建立了求解渗透海床绕射势的边界积分方程,采用高阶边界元方法求解边界积分方程进而得到自由水面的绕射势和波浪在局部渗透海床上传播过程中幅值的变化情况。通过与已发表的波浪对圆柱形暗礁的时域全绕射结果对比,证明了本文建立的频域方法计算波幅的正确性和有效性。利用这一模型研究了三维矩形渗透海床区域上波浪的传播特性,并分析了入射波波长、海床渗透特性系数等参数对波浪传播的影响。     

Zircon U-Pb Geochronology,Geochemistry and Petrogenesis of Early Cretaceous A-type Granites in the Mikengshan Area,Southern Jiangxi ProvinceEI北大核心CSCD

In the Mikengshan-Yanbei area, a special region for the tin mineralization in South China, there are some Yanshanian granites and porphyries and associated porphyry tin deposits (e.g., Yanbei). Although the tin mineralization is closely associated with the granitoids magmatism, the age and petrogenesis of the granites remain controversial. The Mikengshan pluton, which intrudes into the rhyolitic tuff and pyroclastic rocks of the Upper Jurassic Jilongzhang Formation, is the largest one in Mikengshan-Yanbei area and mainly consists of K-feldspar bearing granites. In this study, we report new age and geochemical data for the Mikengshan K-feldspar bearing granites. LA-ICP-MS zircon U-Pb age dating shows that they were generated in the Early Cretaceous (~138 Ma). They have high SiO2 (74.42% to 76.69%), low Al2O3 (12.39% to 13.49%) and Mg# (11 to 19), and negative Eu, Sr and Ba anomalies, and are rich in potassium (most K2O/Na2O=1.37 to 1.94) and high field strength elements (HFSEs), and are weakly peraluminous (A/CNK=1.03 to 1.1) with high 10000×Ga/Al ratios (3.46 to 4.96) and slightly high zircon saturation temperatures (807 ℃ to 817 ℃), showing the characteristics of the typical A-type granites. Moreover, they have high Rb contents 842×10-6 to 1295×10-6, Rb/Sr (90 to 255) ratios and show rare earth elements (REE) tetrad effect, which are similar to those of high fractionated granites. Thus, we suggested that the Mikengshan K-feldspar bearing granites are high fractionated and aluminous A-type granite. Their slightly high εNd(t) values (-3.4 to -4.6) indicate that the mantle components should have played a role during their formation. Taking into account regional igneous rocks and tectonic setting data, we suggest that the Mikengshan K-bearing granites were formed in an extensional setting, which was probably related to the roll-back of the subducted Paleo-Pacific plate. © 2018, Science Press. All right reserved.