云南测震台网地震监测能力分析

2018年1月云南省测震台网示范工程20个新增测震台建设完成,选取原有48个台以及新增20个台连续48小时数据记录,基于近震震级公式,计算并网前后云南省测震台网的地震监测能力,对比测震台增加前后的地震监测能力,发现:云南省地震监测能力由ML 2.2提升到ML 1.6,局部地区由ML1.4提升到ML0.8。     

Subsistence strategies of prehistoric hunter-gatherers on the Tibetan Plateau during the Last Deglaciation

The study of prehistoric hunter-gatherer subsistence strategies on the Tibetan Plateau is important for understanding the mechanisms and processes of human adaption to high altitude environments.But to date,only a few Paleolithic sites have been found on the Tibetan Plateau with clear stratigraphy and reliable dating.These sites are mainly distributed in the Qinghai Lake Basin on the northeastern part of the plateau,and the sporadic fauna and flora remains excavated provide limited information about the subsistence strategies of hunter-gatherers.In 2014,relatively abundant animal remains were unearthed in the Lower Cultural Layer (LCL,15400-13100 cal yr BP) of the"151 site"located in the Qinghai Lake Basin,providing important information about human subsistence strategies on the Tibetan Plateau during the Last Deglaciation.Zooarchaeological analysis of these faunal remains indicates that hunter-gatherers at the"151 site"mainly targeted large ungulates of Bos and wild horse/ass,and only brought back the most nutritious parts of animal carcasses including upper and intermediate limb bones,heads,and trunks (ribs and vertebrae).People then processed and consumed the carcasses around single hearths.Our comprehensive analyses of contemporaneous sites in the Qinghai Lake Basin show that a subsistence strategy involving opportunistic hunting of ungulates,high mobility,and short occupation of campsites was used by terminal Pleistocene huntergatherers to adapt to the high-altitude environment on the Tibetan Plateau.This subsistence strategy may have been a first step of gradual hunter-gatherer adaptation to the extreme conditions on the Tibetan Plateau after the Last Glacial Maximum,and laid the foundation for the widespread distribution of hunter-gatherers on the plateau during the Holocene.     

Imaging the rupture process of the 10 January 2018 MW7.5 Swan island,Honduras earthquake*

The 10 January 2018 M_W7.5 Swan island, Honduras earthquake occurred on the Swan island fault, which is a transform plate boundary between the North American and Caribbean plates. Here we back-project the rupture process of the earthquake using dense seismic stations in Alaska, and find that the earthquake ruptured at least three faults (three stages) for a duration of ~40 s. The rupture speed for the longest fault (stage 3) is as fast as 5 km/s, which is much faster than the local shear wave velocity of ~4 km/s. Supershear rupture was incidentally observed on long and straight strike-slip faults. This study shows a supershear rupture that occured on a strike-slip fault with moderate length, implying that supershear rupture might commonly occur on large strike-slip earthquakes. The common occurrence of supershear rupture on strike-slip earthquakes will challenge present understanding of crack physics, as well as strong ground motion evaluation in earthquake engineering.     

Spatio-temporal differentiation of spring phenology in China driven by temperatures and photoperiod from 1979 to 2018

Large amounts of data accumulated in ecology and related environmental sciences arouses urgent need to explore useful patterns and information in it. Here we propose coclustering-based methods and a temperatures-photoperiod driven phenological model to explore spatio-temporal differentiation in long-term spring phenology in China. First, we created the first bloom date(FBD) dataset in China from 1979 to 2018 using the extended spring indices and China Meteorological Forcing Dataset. Then we analyzed the dataset using Bregman block average co-clustering algorithm with I-divergence(BBAC_I) and kmeans algorithm. Such analysis delineated the spatially-continuous phenoregions in China for the first time. Results showed three spatial patterns of FBD in China and their temporal dynamics for 40 years(1979–2018). More specifically, overall late spring onsets occur in 1979–1996, in which areas located in Jiangxi, northern Xinjiang and middle Inner Mongolia experienced constant changing spring onsets. Overall increasingly earlier spring onsets occur in 1997–2012, in which areas located in Fujian,Hunan and eastern Heilongjiang experienced the most variable spring onsets. Stable early spring onsets over China occur after 2012. Results also showed 15 temporal patterns of spring phenology over the study period and their spatial delineation in China.More specifically, most areas in China have the same FBD category for 40 years while northern Guizhou, Hunan and southern Hubei have the same category in 1979–1997 and then fluctuate between different categories. Finally, our results have certain directive significance on the design of existing observational sites in Chinese Phenological Network.     

基于星载SAR信号的TEC反演新方法

由于星载合成孔径雷达(SAR)系统工作于电离层之上,其信号不可避免地将受到电离层的影响. 背景电离层以及电离层电子密度不规则体多重散射效应可引起距离向图像质量的下降, 在强起伏情况下, 多重散射效应对信号的延迟影响不可忽略. 针对此问题, 本文提出了一种基于SAR回波信号的三频相位自适应TEC反演新方法, 利用反演的结果对电离层的影响进行校正. 给出了校正前后的点目标成像仿真, 结果显示此方法充分考虑了多重散射效应引起的TEC估计误差, 可以有效地补偿电离层对距离向成像的影响, 提高了距离向点目标图像质量.     

灰色误差理论在岩矿测试数据处理中的应用

介绍了灰色误差理论,并应用于岩矿测试数据基本处理。结果表明,在误差变化范围小的岩矿化学分析中,测量数据的累加曲线为线性关系,在元素不均匀性分布的岩矿化学分析(例如不均匀性金的测试)和岩石强度试验等分散性大的测试中,测量数据的累加曲线为曲线关系,但灰色标准偏差和传统统计学的标准偏差非常接近。该方法简单易行,具有相当的精度和较强的实用性,对测量数据少或难于寻求统计规律的测量过程尤为实用,是一种新的尝试。     

三峡小江回水区透明度季节变化及其影响因子分析

三峡成库后其季节调蓄过程使该水域湖沼学特征具有独特性.根据三峡小江流域回水区段为期2年的定位跟踪观测,对透明度(SD)和主要环境指标的相互关系进行分析研究.研究期间,小江回水区透明度均值为170±7cm,各采样点透明度差异不明显且季节变化过程一致,自春末夏初开始降至最低水平,夏季汛期相对稳定,夏末入秋持续升高,冬季维持在较高状态,入春后下降.对透明度和主要环境指标的相关性分析发现,无机悬浮颗粒(PIM)是影响透明度的主要指标.透明度同PIM、Chl.a多元回归模型为:SD=(-89.389±8.101)·lg(PIM)+(-84.008±8.624)·lg(Chl.a)+(264.132±8.232).汛期低水位状态下(145-150m)小江回水区水动力条件趋于天然河道,河道输沙量增加使无机悬浮颗粒含量远高于藻类生物量而成为影响透明度的主要环境指标.在中水位(150-156m)和高水位(156m以上),虽然藻类进入非生长季节,但水位抬升和水体滞留时间的延长促使悬浮颗粒物大量沉淀,悬浮生长于表层水体的藻类成为影响透明度的主要环境指标,生物作用对透明度的影响明显.     

A new species of the glass sponge genus Walteria (Hexactinell-ida: Lyssacinosida: Euplectellidae) from northwestern Pacific seamounts,providing a biogenic microhabitat in the deep sea

We report on a hexactinellid sponge new to science, Walteria demeterae sp. nov., which was collected from the northwestern Pacific seamounts at depths of 1271–1703 m. Its tubular and basiphytous body, extensive lateral processes, numerous oval lateral oscula which are irregularly situated in the body wall, the presence of microscleres with oxyoidal, discoidal and onychoidal outer ends, and the absence of anchorate discohexasters, indicate it belongs to the genus Walteria of family Euplectellidae, which is also supported by molecular phylogenetic evidence from 18S, 28S, 16S rRNA and cytochrome c oxidase subunit I (COI) gene sequences. The unique morphotype, which is structured by a thin and rigid framework of body wall and lateral processes consisting of diactins, characterizes it as a new species. Local aggregations of individuals of this new species coupled with their associated macrofauna in the Suda Seamount are reported, highlighting its functional significance in providing biogenic microhabitats in the deep sea.     

Alentiana palinpoda,a new commensal polynoid species from a seamount in the Northwest Pacific Ocean

Alentiana has only one member, A. aurantiaca (Verrill, 1885), commensal with sea anemone (Bolocera tuediae). Here, Alentiana palinpoda sp. nov., a second member in the genus Alentiana (subfamily Lepidastheniinae), a new commensal polynoid is described, based on a specimen collected from a deep-water seamount in the Northwest Pacific Ocean. The new species is characterized by large elytra that completely cover the dorsum and are present in every third segment in the posterior regions. Neuropodia are truncated, with two types of neurochaetae;supraacicular chaetae toothed on one side with a slightly inflated end, and subacicular chaetae that are heavy and smooth; the prechaetal lobe is larger than the postchaetal lobe, with the ventral part rolling upward and