海洋线虫Litoditis marina早期发育的转录组分析

全球气候和环境变化影响海洋动物的生长发育和繁殖等生命过程,探究环境因子调控发育的分子机制,需要深入了解海洋动物早期发育的生理和分子特征。以实验室驯化的潜在模式动物海洋线虫Litoditis marina为研究对象,对其胚胎期和孵化后发育早期2h、4h和6h的L1幼虫样品进行了转录组测序和分析。结果表明,2h、4h和6h的L1幼虫间差异较小,而三个L1幼虫样品与胚胎期相比,基因表达发生了显著变化。通过KEGG富集分析,发现与胚胎期相比,三个L1幼虫样品的多个通路如核糖体、核糖体生物发生、糖酵解/糖原异生、TCA循环和氧化磷酸化通路相关基因发生了显著上调。另外还发现多个神经递质和神经肽受体基因如dop-和npr-等在L1期转录水平显著上调。与胚胎期相比,L1幼虫的多个DNA复制和修复相关、Notch、Hippo和Hedgehog信号和剪切体等通路相关基因发生了显著下调。发现的L. marina早期发育转录组变化模式与已经发表的陆生模式生物秀丽线虫Caenorhabditis elegans从胚胎期到L1幼虫的转录组变化特征非常相似,但同一上调或下调通路中具体发生表达变化的基因有些不同。另外,L1幼虫显著上调的核糖体生物发生通路相关基因在秀丽线虫中发生了显著下调。进一步通过基因编辑等技术和方法深入研究发育调控关键基因的功能将为海陆近缘线虫间的发育进化机制、海洋线虫对潮间带环境适应以及全球气候变化应答的分子机制研究提供新认知。     

地震电磁辐射观测是短临预测重要手段之一

地震和火山活动是具有相同属性的自然现象,观测表明,在大地震及火山喷发之前的几天或几小时,均呈现有非常宽频谱的电磁辐射和电离层异常现象。本文重点描述了地震前后存在从零开始相当宽频谱的地震电磁辐射以及电离层异常等现象,并提出可利用电离层异常的观测和采用不同频段上地震电磁辐射的立体监测网,作为地震的短临预测、预报手段是现实、可行的。同时还提出了加强我国地震电磁辐射观测研究的建议。     

Development and assessment of damage‐to‐loss models for moment‐frame reinforced concrete buildings

The assessment of earthquake loss often requires the definition of a relation between a measure of damage and a quantity of loss, usually achieved through the employment of a damage‐to‐loss model. These models are frequently characterized by a large variability, which inevitably increases the uncertainty in the vulnerability assessment and earthquake loss estimation. This study provides an insight on the development of damage‐to‐loss functions for moment‐frame reinforced concrete buildings through an analytical methodology. Tri‐dimensional finite element models of existing reinforced concrete buildings were subjected to a number of ground motion records compatible with the seismicity in the region of interest, through nonlinear dynamic analysis. These results were used to assess, for a number of damage states, the probability distribution of loss ratio, taking into consideration member damage and different repair techniques, as well as to derive sets of fragility functions. Then, a vulnerability model (in terms of the ratio of cost of repair to cost of replacement, conditional on the level of ground shaking intensity) was derived and compared with the vulnerability functions obtained through the combination of various damage‐to‐loss models with the set of fragility functions developed herein. In order to provide realistic estimates of economic losses due to seismic action, a comprehensive study on repair costs using current Portuguese market values was also carried out. The results of this study highlight important issues in the derivation of vulnerability functions, which are a fundamental component for an adequate seismic risk assessment. © 2015 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd.     

地浸采铀矿山失效钻孔修复技术初探

经过多年运行,地浸采铀矿山存在大量的失效钻孔,严重影响矿山产能。因过滤器堵塞而造成的失效钻孔占总报废钻孔的80%以上,为此采用切割原有过滤器,下入内置过滤器的方式进行修复,使失效钻孔恢复正常的抽、注液能力。修复结果表明,钻孔抽水量恢复到成孔时初始洗孔水量的95%以上。钻孔修复技术对降低地浸矿山的运营成本,提高矿山服务年限有积极的作用。     

电化学修复过程氢致钢筋塑性降低的影响与控制试验研究

电化学修复技术是提升既有钢筋混凝土结构耐久性重要方法,能有效除去有害氯离子,延长结构使用寿命。采用电化学修复技术对钢筋混凝土结构进行耐久性修复时,作为阴极的钢筋会发生析氢反应,当钢筋表面的氢浓度达到临界值时,钢筋的塑性会降低,并发展成裂纹,导致钢筋出现氢脆现象。开展了不同电化学参数的电化学修复试验,并采用物理方法和力学方法进行了氢致塑性降低的影响分析。结果表明氢致塑性降低与电流密度、应力水平均相关;当清楚工程构件的受力状态时,可采用合适的电流密度对构件进行电化学修复,控制塑性损失程度在工程的可接受范围内,以达到钢筋氢脆控制的目的。     

卤(盐)井维修施工技术探讨

卤（盐）井是岩盐矿山水采方式的主要手段,建井成本高,且每眼井对应一定范围的可采地下资源,对问题卤井的修复具有较广泛意义。根据本矿区卤井维修工程实例,介绍卤井维修施工中一些关键工艺和施工经验。     

ANALYSIS ON THE CHARACTERISTICS OF TROPICAL CYCLONES MAKING LANDFALL ON DIFFERENT REGIONS OF CHINESE MAINLAND

The locations(longitudes and latitudes)of the tropical cyclones(TCs)making landfall on the Chinese mainland from 1949 to 2008 are investigated in detail by using ArcGis and FORTRAN routine.The southeast coastline[110 to 122°E)with most landfall TCs was selected as the key region,which was divided into 12 subsections with 1°intervals of longitude.The study period was from July to September in each year.The result showed that the average sustaining time of TCs making landfall on the subsections east of 118°E is longer than those west of 118°E.Before landfall,the averaged TC intensity in the subsections east of118°E is stronger than that west of it.After landfall,however,the difference between the west and east is not significant.The index of destructive potential for the period before/after landfall was defined as TDP1/TDP2.The maximum of TDP1/TDP2 occurred in the subsection of[119,120°E)/[110,111°E).The ENSO impact on the frequency and average location of landfall TC over the whole region at 110 to 122°E is not obvious,but the effect varies with specific subsections.There is little differences of averaged TDP1 in the subsections between different phases of ENSO events,but the averaged TDP2 is larger in the warm events than that in the cold events.The rainstorm days of each station caused by TCs in different subsections were counted respectively.The results suggested that the rainstorm days of the subsections east of 118°E are much more than those west of 118°E.The larger values are primarily distributed at the subsections of[119,120°E)and[110,111°E).     

粉质砂土土钉墙水平位移与土钉轴力的FLAC3D研究

以物理模型土钉墙的破坏性试验获得的土体的基本参数和模型的尺寸为基础,应用FLAC3D软件建立土钉墙数值模拟模型。通过数值模型模拟基坑开挖与支护过程,并监测该过程中的土钉墙墙体沿深度方向水平位移情况和各层土钉的轴力变化情况以及它们之间的关系。支护过程结束后,在墙顶分级施加竖向荷载直至墙体产生较大变形,研究了土钉墙在超载状况下的工作状况以及破坏过程,并与物理模型土钉墙的破坏性试验结果进行对比。研究发现,开挖过程中墙体水平位移底部大于顶部,呈“勺形”分布;墙体水平位移最大处附近的土钉轴力也最大;粉质砂土土钉墙变形超过基坑开挖深度的4‰后,墙体的稳定性会极大降低;粉质砂土土钉墙没有下卧软弱层时,在地面超载作用下其破坏形式为体内破坏,表现为部分土体沿滑裂面向下滑动。     

不同地形特征下的TLS点云空洞修补精度分析

点云空洞修补是三维激光扫描(Terrestrial Laser Scanning,TLS)技术运用于山地测绘中的一个重要数据处理环节。本文构建了一套基于山谷、山脊和河滩三种地形特征的针对山地测绘的TLS点云空洞修补精度分析方法。并对Geomagic Studio提供的修补算法对不同地形特征下点云空洞中的修补精度进行评价。此外,还通过对比分析实验证明了点云空洞范围内地形特征线的位置与空洞的修补效果之间有密切联系。这为山地区域地面点云空洞修补方法的精度评价提供了一种新的方法。该方法也可以在后期针对复杂地形的点云空洞算法的研究中作为精度验证与评价的方法之一。     

糯扎渡、景洪水库地震监测台网修复重建

糯扎渡、景洪水库地震监测台网于2008年建成,用于监测糯扎渡、景洪水电站周边水库地震活动,受历史原因影响,监测设备老旧,设备用房破损,截至2016年,该水库地震监测台网基本处于停测状态。2017年,华能澜沧江水电股份有限公司对整个水库地震监测台网进行设计优化、修缮,对15个台站及中心机房设备进行维修、更换,恢复台站网地震监测。修缮以后,水库地震台网考核运行率达95%以上,可满足监测M_L≥0.5地震的需求,台网观测的动态范围优于恢复重建前水平。此次糯扎渡、景洪水库地震台网的恢复重建,不仅对水库地震监测起到保障作用,也是对防震减灾事业的重要推进。