高稀释比熔融-X射线荧光光谱法分析硅酸盐岩石样品中18种组分     

卜道露  邱海  龚仓  帅林阳  丁洋 《地质与资源》2021,30(6):740-746

选取土壤、水系沉积物、岩石、超基性岩、黏土等标准物质,应用混合溶剂与样品质量比为14：1的高稀释比方法熔融制备测试样品,拟合校准曲线,建立X射线荧光光谱（XRF）同时测定硅酸盐岩石样品中18种组分（SiO₂、Al₂O₃、TFe₂O₃、MgO、CaO、K₂O、Na₂O、TiO₂、BaO、MnO、P₂O₅、Cr₂O₃、V₂O₅、Rb、Sr、Zr、Cu、Ni）的快速分析方法.应用帕纳科Eagon2全自动高频电感熔样机,称取7.0000 g（45Li₂B₄O₇+10LiBO₂+5LiF）混合溶剂与0.5000 g样品混合均匀,分别加入氧化剂饱和硝酸铵溶液2滴,脱模剂饱和溴化锂溶液4滴,于700℃先预氧化4 min,再1 120℃熔融9 min制备样片,自然冷却至室温.此熔样方法能保证样品中待测组分熔化完全,并制得表面光滑平整的样片.用国家标准物质验证,测试结果的准确度和精密度均符合《地质矿产实验室测试质量管理规范》（DZ/T 0130-2006）要求.  相似文献   

加速溶剂萃取技术在油气化探样品稠环芳烃测定前处理中的应用     

赵江华  李忠煜  何峻  郑民奇 《岩矿测试》2013,32(5):791-795

油气化探样品测定芳烃物质的提取方法通常采用振荡提取,在实际的样品测试过程中,这种前处理方法效率较低,得到的提取液用于分析测定的结果重现性较差。本文对油气化探样品稠环芳烃的提取方法进行改进,采用加速溶剂萃取技术,对实际样品进行试验,考察了压力、静态萃取时间和萃取温度对稠环芳烃萃取效率的影响,确定最佳的萃取条件为: 萃取压力8.3 MPa,静态时间5 min,萃取温度80 ℃。对比了加速溶剂萃取与传统振荡提取应用于油气化探样品前处理的提取效率,证实了加速溶剂萃取技术可以显著提高萃取效率,稠环芳烃的荧光强度提高60.5%~152.6%,方法的稳定性好,测定结果的精密度高,相对标准偏差(RSD, n=7)低于4%。加速溶剂萃取技术优于传统振荡法,更能满足油气化探样品分析测试的准确度与精密度要求,可以应用于油气化探样品前处理过程。  相似文献   

Sample preparation methods for quantitative detection of DNA by molecular assays and marine biosensors     

Annie M. Cox  Kelly D. Goodwin 《Marine pollution bulletin》2013

The need for quantitative molecular methods is growing in environmental, food, and medical fields but is hindered by low and variable DNA extraction and by co-extraction of PCR inhibitors. DNA extracts from Enterococcus faecium, seawater, and seawater spiked with E. faecium and Vibrio parahaemolyticus were tested by qPCR for target recovery and inhibition. Conventional and novel methods were tested, including Synchronous Coefficient of Drag Alteration (SCODA) and lysis and purification systems used on an automated genetic sensor (the Environmental Sample Processor, ESP). Variable qPCR target recovery and inhibition were measured, significantly affecting target quantification. An aggressive lysis method that utilized chemical, enzymatic, and mechanical disruption enhanced target recovery compared to commercial kit protocols. SCODA purification did not show marked improvement over commercial spin columns. Overall, data suggested a general need to improve sample preparation and to accurately assess and account for DNA recovery and inhibition in qPCR applications.  相似文献   

Geographers in Business,Government, and Nonprofit Organizations: Skills,Challenges, and Professional Identities     

M. Beth Schlemper  Joy K. Adams  Michael Solem 《The Professional geographer》2013,65(3):480-492

This study examines the experiences of geography graduates who work in business, government, and nonprofit organizations. We analyzed 352 logs from eighty-two professionals detailing professional activities, challenges, and opportunities during one work week each month, over a period of six months. Our analysis explores interpersonal relationships and working conditions affecting participants’ progress toward work goals, workplace climate, and professional identity. Geographic information systems and technology accounted for more than half of the geographic skills respondents reported using on the job, and administrative and leadership factors were the most commonly cited types of transferable skills. Professional geographers value collaborative workplaces as well as opportunities to work independently with the confidence of their supervisors, and their sense of a professional identity is enhanced when they feel valued and are recognized for their work. Professional development activities are important because they reinforce geographers’ sense of positively contributing to their organizations, enhance interpersonal interactions, facilitate work on specific projects, and expand individuals’ knowledge and skills. Moreover, our findings suggest that nearly half of the reported workplace difficulties could potentially be reduced or eliminated as a result of more and better professional development. Nonetheless, many employers do not consistently provide opportunities for professional development to their employees. Based on our analysis, we contend that professional development is a beneficial investment for lifelong learning, from undergraduate and graduate education throughout the entire course of a professional career.  相似文献   

野战钻井快速造浆机的研制          下载免费PDF全文

吕光辉  訾兵  武平生  何立新 《探矿工程》2012,39(1):18-20

随着近年来给水部队钻井装备的不断更新,钻井设备的自动化程度和施工效率大大提高。与此同时,原来配制周期较长的泥浆配制设备及工艺就显得更加落后,急需进行改进,以适应现代战争对野战给水工程保障快速高效的特点。因此,根据西北水井施工特点和黄土块特征及水井施工实际情况,研制了一种新型快速造浆机。介绍了该新型快速造浆机的工作原理、结构特点和实际使用效果。  相似文献   

榆横矿区赵石畔井田勘探钻探施工技术     

臧世权  汪传武  张波  张涛  郭保铎 《探矿工程》2013,40(4):17-19,23

榆横矿区赵石畔井田勘探中探索和总结钻探工艺,选择合理的设备和机具,使用适合的泥浆体系,特别是肋骨钻头和卡断器配合长岩心管钻具使用,大幅度提高了钻探效率,减少孔内事故,保证施工质量,该工艺对该地区钻探施工有重要意义。  相似文献   

植物胶冲洗液在海洋勘察钻进护孔中的试验应用          下载免费PDF全文

许启云  周光辉  王振红 《探矿工程》2013,40(8):31-34

海洋工程钻探由于受到环境条件的限制,常用海水配制泥浆。由于海水中含盐以及杂质中的Ga2+、Mg2+均对浆液的性能造成破坏,为此,通过对泥浆材料进行选择、配比,并经实践试验得出适合海上钻探环境的护壁泥浆,有效解决了海上钻探泥浆材料选择和具体配制问题。  相似文献   

初始组构各向异性对砂土力学特性及临界状态的影响     

吴越  杨仲轩  徐长节 《岩土力学》2016,37(9):2569-2576

采用离散元方法,利用半径扩展法和重力沉积法分别生成具有初始各向同性和各向异性内结构的试样,并开展三轴不排水压缩和拉伸试验,研究不同制样方法产生的初始各向异性对砂土宏微观力学特性及其临界状态的影响。运用组构张量对砂土的各向异性进行量化,分析不同初始组构各向异性对组构张量演化的影响并确定了组构张量的临界值。试验结果表明：初始组构各向异性对试样的剪胀性有重要影响,由于受重力影响形成初始各向异性,其各向异性程度越大、组构方向与加载方向越一致,剪胀性越显著;初始组构各向异性对试样的临界状态没有影响,砂土的组构张量具有唯一的临界状态值。  相似文献   

Evaluation of antitumor, immunomodulatory and free radical scavenging effects of a new herbal prescription seaweed complex preparation     

LIU Xin  SHAO Changlun  KONG Wenwen  FANG Yuchun  WANG Changyun 《中国海洋大学学报(英文版)》2013,12(3):515-520

Seaweed Complex Preparation (SCP) is a clinical traditional Chinese medicine preparation which is composed of seven traditional Chinese herbs, and it has been used for treatment of lung cancer, liver cancer and digestive cancer. However, little information is available about the pharmacodynamic basis. The antitumor, immunomodulatory and free radical scavenging effects of SCP were evaluated in this study. Transplanted tumor in vivo method was used to determine the antitumor effect. The effects on splenocyte proliferation and phagocytosis of macrophages in tumor-bearing mice were measured by the MTT method and the phagocytizing cock red blood cell (CRBC) method respectively. The scavenging activities of SCP on DPPH and hydroxyl radicals in vitro were investigated. It was found that the medium-dose and high-dose of SCP could significantly inhibit the growth of transplanted hepatic tumor of murine hepatocarcinoma cell line H22, and promote proliferation of splenocytes and phagocytosis of macrophages. SCP possessed noticeable scavenging activities on DPPH and hydroxyl radicals. The antitumor effects of SCP might be achieved by improving immune system and scavenging free radicals, which is in accordance with the viewpoint of traditional Chinese medicine in promoting the body resistance and eliminating pathogenic factors for cancer treatment.  相似文献   

县级土地整治规划编制思路探讨——以诸城市土地整治规划编制为例          下载免费PDF全文

孟艳丽  毛美桥  许庆福  曹玉健  夏孟  丁喜莲  乔庆伟 《山东国土资源》2012,28(3):49-52

诸城市是国土资源部确定的土地整治规划编制6个试点县之一。结合诸城市土地整治规划编制,探讨县级土地整治规划的编制思路。首先准确定位土地整治规划的目标,进行前期研究,总结上轮规划情况,分析土地现状,开展专题研究,然后合理确定规划的目标,因地制宜地进行土地整治分区,最后规范确定土地整治重点项目。  相似文献