青海祁漫塔格地区1∶5万水系沉积物测量方法技术及应用成果

青海省祁漫塔格地区位于柴达木盆地西南缘,是青海东昆仑成矿带西部的重要组成部分。近10年来祁漫塔格地区完成20385km2的1∶5万水系沉积物测量工作,实现了祁漫塔格地区1∶5万水系沉积物测量工作的全面覆盖,提供了大批可供进一步开展工作的化探综合异常和找矿靶区,为祁漫塔格地区矿产资源评价工作提供了翔实的地球化学资料。经异常查证,区内已发现了夏日哈木、铜金山、拉陵高里河沟脑等多金属矿床及一批找矿信息,已证实具有小型-超大型规模,使祁漫塔格地区成为重要的矿产勘查地区。近年来祁漫塔格地区1∶5万水系沉积物测量工作进展及找矿成果表明,1∶5万水系沉积物测量工作对于重要成矿带上矿床的发现具有重要作用,有力推动了祁漫塔格地区矿产资源调查评价工作的开展。     

关中盆地地下热水环境同位素分布及其水文地质意义

通过对关中盆地地下热水^2H、^18O、^13C、^14C、^34S分布特征的研究,阐述了关中盆地腹部与其周边地区地下热水环境同位素异同现象及其水文地质意义,论证了关中盆地地下热水的补给循环及其赋存环境特征。研究表明：关中盆地地下热水中环境同位素δ（^18O）、δ（D）、δ（^13C）、δ（^14C）、δ（^34S）的分布除δ（D）外均呈现中部富集、周边贫化趋势,指示关中盆地腹部咸阳及西安城区1500m以下地下热水赋存环境相对封闭;地下热水滞留时间较长,以碳酸盐矿物溶解为主的水岩反应强烈,热储层中碳酸盐溶解对地热水中的HCO3^-、δ（^18O）、δ（^13C）随深度增加趋势有明显贡献,δ（D）在盆地中部的贫化指示地下热水补给时的温度偏低,根据补给高程计算,西安、咸阳城区地下热水分别为秦岭和北山末次冰期雪水补给。     

陆相页岩岩石学研究方法——以鄂尔多斯盆地东南部下寺湾地区长7、长9段为例

为得出一套适合陆相页岩气储层岩石学研究方法,加快页岩气研究进展,解决页岩气测试技术、评价方法及参考标准的不统一性,采用野外岩心描述、薄片分析、扫描电镜分析及X-衍射相结合的测试手段,参考DB61/577-2013《页岩气井岩样分析测试方法》标准,对鄂尔多斯盆地东南部下寺湾地区长7、长9段页岩岩石学进行分析测试,测试结果表明,下寺湾地区长7、长9段页岩气储层岩性复杂,黏土矿物含量高,石英、碳酸盐等脆性矿物含量少,常规测试方法难以进行精细研究,为此,增加了对测试样品的预处理以及设备的选用,形成一套陆相岩石学研究体系:岩心描述法,薄片鉴定法,扫描电子显微镜与能谱结合法,X射线衍射分析法。     

RELATIVE BRIGHTNESS INDEX AND IT‘S CLIMATIC SIGNIFICANCE FROM LACUSTRINE SEDIMENT OF NAPAHAI LAKE，NORTHWESTERN YUNNAN PLATEAU，CHINA

Information on the palaeoenvironment from Late Pleistocene to Holocene in northwestern Yannan Plateau has been deduced from a study of a 28.81m-long core taken from Napahai Lake.The results from Relative Brightness In-dex(RBI) as well as those from the lithological analyses of bulk sediments,total organic carbon and granulometric analy-ses have been used to reconstruct the environmental and climatic evolution of the area.The ages were provided by three ^14C datings.The record suggested a climate fluctuation between warm-dry and cool-wet from ca.57 to 32ka B.P.which led a shallowing and swamping of the lake.The water level again increased quickly at ca.32ka B.P.,reached itˊs peak during LGM(Last Glacial Maximum,ca.18-20kaB.P.)and remained relative high until ca.15kaB.P.The high wa-ter level at LGM is attributed to cold-wet conditions.The area experienced an abrupt and unstable climatic changes dur-ing the transition period form 15 to 10ka B.P.with a dominated littoral environment.Awarm-dry climate led to the contrac-tion of the lake during the Holocene and reed-swamps became dominant..After a minor wet-cool pulse during the Late Holocene,the modern climate became to be established.     

Deep Hubble space telescope ultraviolet imaging of the M87 jet

Near-ultraviolet imaging with HST offers the best possible spatial resolution currently available for optical/UV astronomical imaging. The giant elliptical galaxy M87 hosts one of the most spectacular, best studied and nearest (d=16 Mpc) galactic-scale relativistic (synchrotron emitting plasma) jets. We have extracted from the HST archive all 220 nm images of the jet of M87, taken with the STIS MAMA camera and co-added them to provide the deepest image ever at this wavelength. The combination of highest spatial resolution and long integration time, 42500 seconds, reveals a wealth of complex structure, knots, filaments and shocks. We compare this image with deep X-ray observations obtained with the Chandra X-ray telescope.     

一种基于元学习的大口径射电望远镜俯仰轴承故障辨识方法研究

在经过长期运行后大口径射电望远镜俯仰轴会出现微小扭曲, 滚动轴承作为承载俯仰轴的核心部件, 也会因长期承受交变载荷增加疲劳风险, 导致轴承寿命以及望远镜指向精度的下降, 极大影响望远镜的性能. 以俯仰轴承为研究对象, 开展故障辨识方法研究, 可为望远镜天线的高性能运行提供重要支撑. 为实现在有限数据和复杂工作条件下准确地辨识俯仰轴承故障, 提出了一种小样本条件下基于元学习的故障辨识方法(Few-shot Meta-learning Fault Identification, FMFI). 首先将不同工况下的原始信号转换为时频图像数据, 之后按照元学习协议将数据样本随机采样到不同的学习任务中. 在有限样本的条件下, FMFI可以通过训练任务中的样本信息获取通用的先验知识, 在未知的测试任务下实现准确快速的故障辨识. 选取了与望远镜俯仰轴承工况具有相似性的变负载轴承数据集进行实验, 实验结果表明, FMFI方法具有很高的准确性和可靠性, 为大口径射电望远镜俯仰轴承的主动运维和高质量服役提供了有力的技术支持.     

The non-oxidative dissolution of galena nanocrystals: Insights into mineral dissolution rates as a function of grain size, shape, and aggregation state

The acidic, non-oxidative dissolution of galena (PbS) nanocrystals has been studied in detail using transmission electron microscopy (TEM) to follow the evolution of the size and shape of the nanocrystals before and after dissolution experiments, X-ray photoelectron spectroscopy (XPS) to follow particle chemistry, and dissolution rate analysis to compare dissolution rates between nanocrystalline and bulk galena. Dissolution characteristics were also studied as a function of nanocrystal access to bulk vs. confined solution due to the degree of proximity of next-nearest grains. Nearly monodisperse galena nanocyrstals with an average diameter of 14.4 nm were synthesized for this study, and samples were exposed to pH 3, deoxygenated HCl solutions for up to 3 h at 25 °C. Detailed XPS analysis showed the nanocrystals to be free of unwanted contamination, surface complexes, and oxidative artifacts, except for small amounts of lead-containing oxidation species in both pre- and post-dissolution samples which have been observed in fresh, natural bulk galena. Depending on the calculation methods used, galena nanocrystals, under the conditions of our experiments, dissolve at a surface area normalized rate of one to two orders of magnitude faster than bulk galena under similar conditions. We believe that this reflects the higher percentage of reactive surface area on nanocrystalline surfaces vs. surfaces on larger crystals. In addition, it was shown that {1 1 1} and {1 1 0} faces dissolve faster than {1 0 0} faces on nanocrystals, rationalized by the average coordination number of ions on each of these faces. Finally, dissolution was greatly inhibited for galena nanocrystal surfaces that were closely adjacent (1-2 nm, or less) to other nanocyrstals, a direct indication of the properties of aqueous solutions and ion transport in extremely confined spaces and relevant to dissolution variations that have been suspected within aggregates.     

江西武宁县石门寺钨铜矿区风化作用过程中W、Cu等元素的表生地球化学行为（之一）

以江西省武宁县石门寺钨铜矿区燕山期和晋宁期岩体风化作用过程中W、Cu等元素的表生地球化学行为为研究对象,通过反映风化程度的化学风化指数CIA、风化作用过程中组分得失的估算、不同介质中W、Cu等成矿元素的含量变化及大离子亲石元素表生地球化学行为等方法的研究表明,石门寺钨铜矿区2个时期岩体元素淋失与风化强度有关,土壤剖面中碱金属、碱土金属元素大量淋失,而W、Cu等成矿元素在土壤B层中显著富集;从岩石到土壤、再到水系沉积物风化过程中,W、Cu等成矿元素含量逐渐升高,为此,一级水系沉积物和B层土壤是赣北九岭W、Sn、Cu、Mo多金属矿集区地球化学找矿的绝佳采样介质,是矿集区内找矿新突破的有效手段。