SEDIMENTARY ENVIRONMENT IN TAIWAN SHOAL

Taiwan Shoal sediments are well sorted and rounded medium-coarse sands eontaining a large amount of shell and beach rock fragments and basalt gravels, and are of deltaic, coastal and eolian origin. Underwater sand waves are formed by the combined tidal currents and are remolded by storm waves.     

平潭岛岚湖沉积环境和成因的研究

在中全新世后阶段，当海岸风沙正处于始发状态，平潭西南的岗湖还是一个由多叉的山谷组成的洼地。到全新世晚期，由于全球气候的变化和优势的北北东方向风力的逐渐增强，河谷洼地与海湾相联结的地区长时间风沙的堆积而形成岚湖。     

中国小城镇产业结构特征及影响因素研究

分析揭示了2015年中国小城镇产业结构特征与空间差异,并利用加权最小二乘法实证估计了中国小城镇非农产业占比的影响因素。研究得出中国小城镇非农产业占比呈正态分布,非农产业占比较高的区域主要集中在东部沿海、长江经济带和边境口岸地区。东部地区小城镇非农产业占比呈负偏态分布,中部地区呈正态分布,而西部和东北地区则呈现正偏态分布特征,产业结构相对落后。小城镇规模、所在县域经济发展水平与小城镇非农产业占比显著正相关。县域第二产业占比提高带来的拉动效应略高于第三产业,小城镇产业更多的是为县域第二产业发展提供配套支撑。地级城市（地区、自治州、盟）规模的扩大对辖区内小城镇产业结构升级产生的扩散效应强于虹吸效应。     

Holocene vegetation and hydrology variations and their associations with climate changes: a multi-proxy analysis of a sediment core from an alpine basin in the middle Tianshan Mountains

We in this paper present a multi-proxy study of a 186-cm-long lacustrine sediment core (i.e., BY Core) obtained from the Youerdusi Basin in the middle Tianshan Mountains in an attempt to disentangle the causal associations among climate changes, ecological responses and hydrological variations. Palynological, assemblages and the associated biome scores indicate that the upper limit of the forest zone was closer to the Youerdusi Basin with a larger wetland extent in the Youerdusi Basin during the early part (i.e., from ~ 10.5 to ~ 5.8 cal. kyr BP) of the data-covering period (i.e., from ~ 10.5 to ~ 2.4 cal. kyr BP). The upper limit of the forest zone was farther away from the Youerdusi Basin with a smaller wetland extent in the Youerdusi Basin during the late part (i.e., from ~ 5.8 to ~ 2.4 cal. kyr BP). The changes of taiga biome score and the AP% ratio indicate a persistent cooling trend during the data-covering period which is well corroborated by various proxy data from nearby sites and the cooling trend is chronologically consistent with the trend of Northern Hemisphere temperature anomalies that was interpreted to be a delayed response to the summer solar irradiance at 50° N. The tundra biome score and the associated percentages of Cyperaceae in the Youerdusi Basin show two major stages of wetland extent variation. The wetland extent variation in the Youerdusi Basin might have been controlled by precipitation and/or by glacier-melting potential that was in turn controlled by both temperature and the extent of remained ice cover in higher elevations. The δ¹³C_org values obtained from the BY Core indicate a wetting trend during the data-covering period which is reasonably corroborated by various proxy data from nearby sites. We infer that the wetting trend was causally associated with the Holocene increasing trend of the North Atlantic Ocean SST (sea surface temperature) and also with the Holocene increasing trend of the westerlies’ intensity.

     

浅地层剖面仪在海岸工程上的应用

现代海湾的迅速沉积其物源来自河流入海泥量的猛增。浅地层剖面仪以灵敏度和分辨率高，连续性好且能快速地探测不同沉积层的特征及其分布。在海湾工程中，无论是航道整治还是码头选址和施工勘探都可以应用浅地层剖面仪作为先头“侦察兵”而获得良好的结果。其优越性是节省投资、加快建设进度，又提高勘探质量，帮助设计和施工部门快捷地解决那些需要解决的而常规方法又难以完成的问题。     

海坛岛芦洋浦平原的海进沙与风沙层序

本文研究了福建海坛岛芦洋浦平原的海进沙与风沙层序。结果表明,芦洋浦平原原是一个水深20～30m、走向NNE的海湾,全新世初期的海进沙层厚2～5m覆盖在陆相冲积和风化层上。后来,海平面波动,从台湾海峡推来残留沙超覆其上。经一段时间的正常环境后,距今约2400～2000a,由于地球气候的变化,风沙逐渐发育,厚5～10m的风沙层埋盖了海湾沉积,建造了面积68km~2的大沙坪和半封闭的泻湖。     

The November 2004 superstorm: Comparison of low-latitude TEC observations with LLIONS model results

We investigate the effects of penetration electric fields, meridional thermospheric neutral winds, and composition perturbation zones (CPZs) on the distribution of low-latitude plasma during the 7–11 November 2004 geomagnetic superstorm. The impact on low-latitude plasma was assessed using total electron content (TEC) measurements from a latitudinally distributed array of ground-based GPS receivers in South America. Jicamarca Radio Observatory incoherent scatter radar measurements of vertical E×B drift are used in combination with the Low-Latitude IONospheric Sector (LLIONS) model to examine how penetration electric fields and meridional neutral winds shape low-latitude TEC. It is found that superfountain conditions pertain between ～1900 and 2100 UT on 9 November, creating enhanced equatorial ionization anomaly (EIA) crests at ±20° geomagnetic latitude. Large-amplitude and/or long-duration changes in the electric field were found to produce significant changes in EIA plasma density and latitudinal location, with a delay time of ～2–2.5 h. Superfountain drifts were primarily responsible for EIA TEC levels; meridional winds were needed only to create hemispherical crest TEC asymmetries. The [O/N₂] density ratio (derived from the GUVI instrument, flown on the TIMED satellite) and measurements of total atmospheric density (from the GRACE satellites), combined with TEC measurements, yield information regarding a likely CPZ that appeared on 10 November, suppressing TEC for over 16 h.     

正定矩阵一维三角分解法及其应用

由文献［１］知,正定矩阵三角分解后,下三角阵中各元素在阵中的位置具有一定的分布规律,为此可将矩阵中用二维形式表示的诸元素利用位置函数表示为一维形式,文献［１］中所有利用下三角阵各元素进行计算的公式也都可表示为一维形式,使程序设计简单易行。     

正定矩阵的三角分解与线性对称方程组的解算

讨论用正定矩阵三角分解法解线性对称方程组的问题,将具有正定系数阵的线性方程组中的正定矩阵分解为两个互为转置的上、下三角阵之积,用比较法导出下三角阵诸元素与原矩阵诸元素之间的关系式,再将分解式代入原方程,从而导出用三角分解法解线性对称方程组的计算公式,此法计算规律性强,既适用于手算又适用于电算,可在测量平差等科学计算中广泛应用。     

Antiplane response of two scalene triangular hills and a semi-cylindrical canyon by incident SH-waves

Antiplane response of two scalene triangular hills and a semi-cylindrical canyon by SH-waves is studied using wave function expansion and complex function method. Firstly, the analytical model is divided into three parts, and the displacement solutions of wave fields are constructed based on boundary conditions in the three regions. Three domains are then conjoined to satisfy the "conjunction" condition at shared boundary. In addition, combined with the zero-stress condition of semi-cylindrical canyon, a series of infinite algebraic equations for the problem are derived. Finally, numerical examples are provided and the influence of different parameters on ground motion is discussed.