跨越断层埋地管线地震反应研究述评

本文论述了跨越断层埋地管线地震反应研究工作概况,包括理论研究和实验研究的进展,并介绍了不同情况下采用的研究方法和建立的相应的研究模型,通过对数据结果进行整理分析,得出跨越断层埋地管线地震反应规律。同时,本文还对埋地管线研究中的一些重要参数对研究结果的影响作了详尽的阐述,提出了需进一步研究的问题和今后可能的研究发展方向。     

Research on red tide occurrences using enclosed experimental ecosystems in west Xiamen Harbor, China—Relationship between various factors and red tide occurrences

A series of enclosed ecosystem experiments were conducted in a land-based tank near the seaside of West Xiamen Harbor. The results of experiments conducted in different seasons and years showed a repeatable phytoplankton succession. In this relatively stable ecosystem with added nutrients and trace metals, diatoms dominated initially, dinoflagellates dominated in the later stage, and dinoflagellate red tides eventually occurred. Vitamin B₁₂ enrichment may speed up this succession process. Stirring the water column could stop this process. Soluble Mn at a level of 3–4 μg/L in seawater, which also is the existing concentration of soluble Mn in Xiamen Harbor seawater, is sufficient for the multiplication of algae and occurrence of red tide. The present study showed that excessive soluble Mn in Xiamen Harbor cannot cause red tide, and that Fe was one of the important factors causing diatiom red tide in this present study. Project 39570145 supported by NSFC.     

帕米尔东北缘穷阿木太克岩体年代学、地球化学特征及地质意义

分布于帕米尔东北缘羌塘地块上的穷阿木太克岩体,与班公湖怒江洋的闭合有着密切关系。岩体主要由英云闪长岩、花岗闪长岩和二长花岗岩组成。LA-ICP-MS锆石U-Pb测年结果显示,穷阿木太克岩体的形成年龄为(107.0±1.2) Ma(MSWD=0.55),属于早白垩世晚期。地球化学结果显示,主量元素具有富Ca、富K、富碱等特点,岩石Al含量较高,为弱过铝质花岗岩系列,具典型的钙碱性特征。稀土元素具有轻稀土富集、重稀土亏损的右倾型特征,并显示弱的负铕异常。微量元素表现出大离子亲石元素Rb、Th、U、K高度富集和高场强元素Nb、Ta、Ti、Hf强烈亏损。岩石在成因上可能是地壳下部基性岩石经熔融或部分熔融作用形成的。结合本区所处的构造环境,早白垩世晚期穷阿木太克岩体可能形成于羌塘地块与冈底斯地块之间同碰撞(挤压环境)向碰撞后(伸展环境)的转化阶段,为后造山花岗岩类,岩石系列从早到晚由中钾钙碱性系列向钾玄岩系列演化。     

天文观测科学实践中心技术实现

天文观测科学实践中心是一个以天文观测为核心的网络实践体验中心,以网站的形式向公众提供服务。网站建设使用HTML、CSS、JavaScript和JSP/JaveBean等技术;基于B/S结构实现望远镜远程控制;采用Windows Media技术实现视频发布。建成的网站为用户提供了全新的天文观测实践体验机会,达到了传播天文知识的目的。     

上高县紫皮大蒜种植气候适宜性区划

基于紫皮大蒜生长周期和当地农业气象条件,得到上高县紫皮大蒜气候适宜性指标：10—11月的最低气温、10月至次年4月的平均气温和平均降水量以及2—4月的累计日照时数。利用1970—2020年宜春市和新余市辖区内共12个地面观测站的气象资料,采用GIS建立上高县紫皮大蒜种植区划因子地理空间分析模型。依据分区等级指标,将上高县划分为最适宜、一般适宜和不适宜3个紫皮大蒜气候种植区。     

南极普里兹湾及其邻近海域水团研究

普里兹湾及其邻近海域是中国南大洋调查研究的传统优势海域与重点区域。围绕夏季表层水、冬季水、陆架水、绕极深层水、南极底层水、普里兹湾底层水、冰架水等研究海区主要水团的特征和分布,总结了前人在南极普里兹湾及其邻近海域基于调查资料开展的水团研究中所取得的成果。研究表明,前人在对陆架水的示性指标界定上,将陆架水是否区分为高盐陆架水和低盐陆架水存在较大争议,在高盐陆架水和普里兹湾底层水的定义上存在重叠;目前尚没有证据表明绕极深层水向南可以伸展到普里兹湾的陆架区域,也没有发现在普里兹湾附近海域生成南极底层水的直接证据。     

“4D”技术及其应用

介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。     

Is it possible to detect earlier ionospheric precursors before large earthquakes using principal component analysis (PCA)?

The goal of this study was to determine whether principal component analysis (PCA) can be used to process GPS ionospheric total electron content (TEC) data on a monthly basis to identify early earthquake-associated TEC anomalies. PCA is applied to GPS (mean value of a month) ionospheric TEC records collected from the Japan GEONET system to detect TEC anomalies associated with 10 earthquakes in Japan (M?≥?6.0) from 2006 to 2007. According to the results, PCA was able to discriminate clear TEC anomalies in the months when all 10 earthquakes occurred. After reviewing the months when no M?≥?6.0 earthquake occurred but the geomagnetic storm activity was present, it is possible that the maximal principal eigenvalues PCA returned for these 10 earthquakes indicate earthquake-associated TEC anomalies. Previously, PCA has been used to discriminate earthquake-associated TEC anomalies recognized by other researchers who found that a statistical association between large earthquakes and TEC anomalies could be established in the 5 days before earthquake nucleation and in 24 h before earthquake; however, since PCA uses the characteristics of principal eigenvalues to determine earthquake-related TEC anomalies, it is possible to show that such anomalies existed earlier than this 5-day statistical window. In this paper, this is shown through the application of PCA to one-dimensional TEC data relating to the earthquake of 17 February 2007 (M?=?6.0). The analysis is applied to daily TEC and reveals a large principal eigenvalue (representative of an earthquake-associated anomaly) for 02 February, 15 days before the 17 February earthquake.     

集成Landsat OLI和机载LiDAR条带数据的亚热带森林生物量制图

以亚热带天然次生林为研究对象,借助一个条带的少量LiDAR点云数据和覆盖整个研究区的免费Landsat OLI多光谱数据,并结合地面实测数据,探索森林生物量低成本高精度制图方法。首先,提取了OLI和LiDAR特征变量,并与地上和地下生物量进行相关分析以筛选变量;然后,借助LiDAR数据覆盖区的样地和条带LiDAR数据构建"LiDAR生物量模型";再从LiDAR反演生物量的结果中进行采样,结合OLI特征变量构建"LiDAR-OLI模型";最后,与单独使用OLI多光谱数据建立的"OLI估算模型"结果进行比较,分析精度并验证新方法的效果。结果表明,"LiDAR-OLI模型"对地上和地下生物量的模型拟合效果较好且均优于"OLI模型",且其交叉验证的精度也较高并优于"OLI模型",从而证明了新方法的可靠性及有效性。本研究为主、被动遥感技术在中小尺度上协同反演森林参数提供了实验基础,也为基于全覆盖免费OLI多光谱数据及条带LiDAR数据的低成本森林生物量制图探索了技术路线。     

一种可业务化的雷电潜势预报方案

利用2000～2005年的闪电定位资料、常规气象观测资料,实时业务应用的数值预报产品以及NCEP/NCAR再分析资料等,基于雷电发生的天气学分型和完全预报方法原理,以可业务实时实现为原则,对广州地区雷电的短期潜势预报进行了研究,引入了"马赛克化"、不确定度概念以及多元回归、线性/非线性拟合方程等数学统计方法,得到一种较有效的雷电短期潜势预报方案,该预报方案在实时业务预报中试用,预报结果对雷电潜势预报具有参考价值.