Typhoon disaster in China: prediction,prevention, and mitigation

Typhoon-induced disaster is one of the most important factors influencing the economic development and more than 250 million in China. In view of the existing state of typhoon disaster prediction, prevention, and mitigation, this paper proposes a new probability model, Multivariate Compound Extreme Value Distribution (MCEVD), to predict typhoon-induced extreme disaster events. This model establishes prevention criteria for coastal areas, offshore structures, and estuarine cities, and provides an appropriate mitigation scheme for disaster risk management and decision-making.     

鲁西南地区土壤中有机氯农药的残留及其分布特征

在鲁西南地区1.08×104km2的范围内以1点/36km2的采样密度采集表层土壤299件,测试六六六（HCH）、滴滴涕（DDT）等10项指标。研究这些指标的含量变化,发现区内土壤中停用20多年的六六六（HCH）、滴滴涕（DDT）仍有较高的检出率。土壤中六六六（HCH）4种异构体β-HCH含量最高, P,P′-DDE和P,P′-DDD为滴滴涕（DDT）的主要存在形式;进一步研究α-HCH／γ-HCH、β-HCH／γ-HCH和（P,P′-DDE＋P,P′-DDD）/P, P′-DDT值的变化规律,得出调查区内仅滴滴涕（DDT）在局部可能存在新的污染源输入,而大部分地段六六六（HCH）、滴滴涕（DDT）农药使用时间较长,其组分已经通过物理、化学等作用发生了很大变化,污染是过去形成的。土壤环境质量评价结果表明区内土壤质量能保障农业生产、维护人体健康。     

Sedimentary Response of Different Fan Types to the Paleogene-Neogene Basin Transformation in the Kuqa Depression,Tarim Basin,Xinjiang Province

A group of alluvial fans formed in the early Paleogene represent marginal sedimentary facies at the foot of the South Tianshan Mountain,Kuqa Depression,Tarim Basin,Xinjiang province. Two types of fans occurred in the middle-late Paleogene Kumugeliemu and Suweiyi formations:one alluvial,and the other fan delta deposited in a lacustrine setting.Within the early Neogene Jidike Formation,coastal subaqueous fans developed,probably in a deeper water lacustrine setting.The three types of fans are stacked vertic...     

Filling History and Post-Breakup Acceleration of Sedimentation in Baiyun Sag,Deepwater Northern South China Sea

The Baiyun (白云) sag in the southern Pearl River Mouth basin is the largest and deepest sag in deepwater northern South China Sea.Researches and exploration in this sag have revealed many distinct features of the sag.This article reports its filling history through backstripping of depth data of interpreted sequence boundaries.Maps of sediment rates of 10 sequences from 49 Ma to the present were constructed,showing the spatio-temporal variation of the sediment rate.Three stages of sediment infilling,49-17.5 Ma,17.5-10.5 Ma,and 10.5-0 Mn,were divided by abrupt changes of sedimentary patterns.If the breakup of the South China Sea took place at ～30 Mn,significant pint-breakup acceleration of sedimentation was observed at 17.5-15.5 Ma and 13.8-12.5 Mn,indicating acceleration of subsidence at these times.We propose that the onset of strong post-breakup snbsidence at ～17.5 Ma was an important tectonic event that changed the pattern of sedimentation from discrete and medium-rate depmition centers in both main and south snbsags to restricted but high-rate deposition in the main snbsag.The cause and implications of this newly recognized event need tobe investigated.     

基于气候统计特征的雷达回波质控方法

利用北京南郊S波段雷达2011—2016年的观测资料,从雷达气候统计的角度,利用不同强度回波发生频率的统计特征及其空间分布特征,对雷达地物杂波和波束遮挡的识别与订正方法进行研究。结果表明:①利用雷达回波出现频率特征,可以很好地识别雷达近中心地物杂波和受地形高度影响的地物杂波特征;同时还可以直观地识别出雷达波束遮挡区域以及遮挡程度。北京南郊雷达地物杂波主要分布在近雷达中心和北京西部、西北部的山前地区,地物杂波主要集中在0.5°仰角和1.5°仰角层上。雷达波束遮挡主要集中在由高大建筑引起遮挡的东南方位向和由于地形引起波束遮挡的西西北方位向,波束遮挡主要集中在0.5°仰角层。②采用局部可变区域平均垂直廓线方法利用高仰角回波订正低仰角回波,能有效订正地物杂波,并保留回波的局部特征。对于波束遮挡区域的回波填补,也能够较好地保持上下层仰角回波之间的连续性,同时兼顾了回波不均性分布等特性。③基于雷达气候特征进行地物杂波识别和波束遮挡识别,无需依照先验知识,相比于传统方法能更好地反映本地雷达回波真实情况,且具有方法简单、可快速复用、本地适用性强等优点。     

First Results of Dating Detrital Zircons from the Late Precambrian Quartzite–Schist Sequences of the Chu Block (Southern Kazakhstan)

Doklady Earth Sciences - U–Pb geochronological studies of detrital zircons from quartzite–schist sequences of the Akbastau Formation of the Chu Block (northwestern part of the...     

淮河上游全新世黄土与成壤环境变化

Based on field surveys, soil samples were collected at the YPC site, Yuzhou City, Henan Province for analysis of contents of major and trace elements and their variations with XRF and comparison with the curves of magnetic susceptibility, pH value distribution, loss on ignition and particle-size distribution. It was concluded that the dust source of loess in the upper reaches of the Huaihe River Basin was different from that in the Loess Plateau. And the Holocene pedogenic environmental changes in the upper reaches of the Huaihe River Basin were revealed. Foundation: National Natural Science Foundation of China, No.40571154; No.40471119 Author: Li Xinyan (1978–), Ph.D, specialized in resource exploitation and environmental science.     

准噶尔盆地南缘古近纪—新近纪前陆盆地沉积格局与演变*

针对准噶尔盆地南缘古近系和新近系碎屑岩沉积体,运用野外露头宏观分析与岩心、薄片微观描述来 “定岩相和沉积相”;依据地震相的不同特点及相变的不同位置,刻画湖岸线演化,从而对沉积体“定边界”;根据重矿物组合特征及砂岩等厚图来“定主次物源”的方法,综合研究前陆盆地的沉积相特征。在此基础上,分析了准噶尔盆地南缘湖盆沉积格局与演变,认为准噶尔盆地南缘古近系紫泥泉子组沉积时期,湖平面较低,天山山前带发育4个规模较大的扇三角洲朵状体;至安集海河组沉积时期,湖平面上升,山前带扇三角洲发生退积,仅沉积3个规模变小的朵状体,霍尔果斯地区扇三角洲朵状体不发育。新近系沙湾组沉积时期,由于逆冲推覆构造作用,山前带地形高差大、坡度陡且气候干旱,随着湖平面的迅速下降,山前带发育更大规模进积型扇三角洲沉积。准噶尔盆地南缘古近系—新近系2个主要物源分别是中部东湾—吐谷鲁—玛纳斯背斜、西部西湖—独山子背斜;2个次要物源分别为东部呼图壁背斜和中西部霍尔果斯背斜,此4个物源流向是由南向北。北部卡因迪克地区则是来自前陆隆起区的重要物源。     

超滤技术在卡拉胶低聚糖分离纯化中的应用

超过滤法是在常规微粒过滤基础上发展起来的细微粒子过滤新技术,是膜法分离的一种,在化工、制药和食品等工业中以及在医学、生物学和环保等领域中都得到了广泛的应用。本文采用超过滤法对卡拉胶低聚糖进行了分离纯化,结果表明超滤可快速简便地将高分散性的低聚糖体系分成几个分子量不同的组分。