Scanning electron microscopy coupled with energy-dispersive X-ray spectrometry for quick detection of sulfur-oxidizing bacteria in environmental water samples

Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry (EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time (within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.     

Late Triassic post-collisional slab break-off along the Ailaoshan suture: insights from OIB-like amphibolites and associated felsic rocks

International Journal of Earth Sciences - What dynamic processes the South China-Indochina collision had gone through is still a pending problem. Our recent investigations identified a Late...     

青海多彩当江地区水系沉积物元素地球化学结构特征及找矿方向

青海多彩当江地区位于三江多金属成矿带,具有较好的找矿前景。以该区1∶5万水系沉积物地球化学测量数据为研究对象,结合研究区内的米扎纳能铜-铅-锌多金属矿床的水系沉积物地球化学结构特征与地质特征进行了剖析,总结了研究区的地质-地球化学找矿标志,并提出了龙格东多铜-锌多金属找矿远景区,为该区的找矿工作提供了新方向。     

Effects of vegetation restoration on local microclimate on the Loess Plateau

With the implementation of the Grain for Green Project,vegetation cover has expe-rienced great changes throughout the Loess Plateau (LP).These changes substantially in-fluence the intensity of evapotranspiration (ET),thereby regulating the local microclimate.In this study,we estimated ET based on the Penman-Monteith (PM) method and Priestley-Taylor Jet Propulsion Laboratory (PT-JPL) model and quantitatively estimated the mass of water vapor and heat absorption on the LP.We analyzed the regulatory effect of vegetation resto-ration on local microclimate from 2000 to 2015 and found the following:(1) Both the leaf area index (LAI) value and actual ET increased significantly across the region during the study period,and there was a significant positive correlation between them in spatial patterns and temporal trends.(2) Vegetation regulated the local microclimate through ET,which increased the absolute humidity by 2.76-3.29 g m-3,increased the relative humidity by 15.43％-19.31％and reduced the temperature by 5.38-6.43℃ per day from June to September.(3) The cooling and humidifying effects of vegetation were also affected by the temperature on the LP.(4) Correlation analysis showed that LAI was significantly correlated with temperature at the monthly scale,and the response of vegetation growth to temperature had no time-lag effect.This paper presents new insights into quantitatively assessing the regulatory effect of vege-tation on the local microclimate through ET and helps to objectively evaluate the ecological effects of the Grain for Green Project on the LP.     

武山台数据信息管理系统设计与实现

根据武山水化学综合地震台的具体情况，在微机汉字ＤＯＳ环境下利用ＦｏｘＢＡＳＥ＋２．１０关系型数据库成功开发了武山台数据信息管理系统。本系统全部采用Ｆｏｘｂａｓｅ＋数据库编写，主要用于地震台站的数据管理及各种报表的自动生成。程序采用自项向下，逐步求精方法设计，全部功能模块均采用下拉式窗口。程序设计中，最大限度地采用了容错处理。一年多的实际运行表明，系统操作简单，界面友好，容错功能完善，完全满足台站日常工作需要。     

测震系统标定的改进

本文对常用的通过测中肯电阻标定测震系统的方法进行了分析并提出了改进，以期提高标定工作的精度和速度。主要有，第一用自制的高精度周期仪代替人工读秒表的测周期方法；第二用空气阻尼监测仪快速地监测空气阻尼以落实拾震器的装配状况；第二对衰减振动的记录图提出了数据修正以提高测量程度。     

国内外“人工矿床”研究现状与前景

“人工矿床”主要是指废石及尾矿等能被重新利用的资源，在富矿资源日益减少的今天，贫矿资源，废石及尾矿等非传统资源的开发利用越来越受到重视，目前，国内外主要从物质再回收和物质转移两个方面对废石和尾矿的综合利用进行研究。国外已利用细菌浸出等先进的矿物加工工艺从低品位的含铜和含金的废石和尾矿中回民铜和金，利用已无回收价值的尾矿加工制造水泥，陶瓷，玻璃等新型材料，国内主要利用重选，磁选，浮选，化学选矿联合工艺流程回民铁，铜，金等尾矿中的有用元素,利用废石，尾矿作建筑石料或加工制造砖，混凝土，陶瓷等建筑材料。     

国际地震电磁学术讨论会与震磁研究进展概述

在地震预测研究中，震磁研究是一项重要的研究课题。文章简要介绍了2000年9月19－22日在日本东京召开的“国际地震电磁学学术讨论会”，以及中、美、日、俄等国家的震磁研究进展，表明震磁前兆在地震预测研究中具有一定的实际效果与良好的研究前景。     

再论华南沿海温泉分布与地震活动关系

华南沿海温泉和地震的关系是通过断层这一桥梁实现的，它们中存在既相辅相成又互为消长的两个因素，初步提出衡量断层热震关系的α'值概念，探讨温泉和地震之间可能存在的关系。