海水中溶解态铵盐氮同位素分析的预处理方法     

刘丽丽  于海燕  俞志明  宋秀贤  曹西华  袁涌铨 《海洋科学》2013,37(12):28-33

以蒸馏法为基础, 研究了适合海水中铵盐稳定氮同位素分析的预处理方法。对蒸馏法预处理过程中的最佳蒸馏时间、沸石的选取、铵盐最适浓度范围等分别进行改进和优化, 获得稳定、高效的海水中铵盐氮稳定同位素分析预处理方法。结果表明: 最佳蒸馏时间为50 min, 铵盐的回收率为(97±5.8)%。测定了不同沸石对不同浓度氨氮的吸附率, 筛选出酸性条件下铵氮吸附效率较高且稳定的康华科技沸石; 确定铵盐的最佳适用浓度范围为2～10 μmol/L, 在该浓度范围内氮回收率94%～99%,氮分馏系数为0.1‰～0.8‰。将此方法应用于长江口海域水样分析, 结果表明, 这一方法可以应用于河口中铵盐的氮同位素分析, 能够为河口中溶解态氮的来源及循环机理等研究提供有效信息。  相似文献   

铼-锇同位素分析样品预处理研究进展   总被引：1，自引：0，他引：1  

黄小文  漆亮  高剑峰 《岩矿测试》2011,30(1):90-103

文章评述并归纳了近年来地质样品中Re-Os同位素分析的化学前处理方法研究进展。总结了锍镍火试金法、碱熔法、Carius管溶样法以及HPA-S高温高压釜溶样法等常用的Re-Os同位素样品消解方法。归纳了离子交换、溶剂萃取富集Re以及蒸馏、萃取等分离富集Os的方法。由于地质样品的复杂性,Re、Os含量的不均一性及测试方法的多样性,要求在具体分析过程中不同的样品使用不同的消解方法和分离富集方法。当前国内应用较成熟的Re、Os分离方法是Carius管逆王水分解样品,原位蒸馏或CCl4萃取方法分离Os,阴离子交换法或丙酮萃取分离Re。  相似文献   

The death spiral of coal in the U.S.: will changes in U.S. Policy turn the tide?     

Roman Mendelevitch  Christian Hauenstein  Franziska Holz 《Climate Policy》2013,13(10):1310-1324

ABSTRACT

The administration of U.S. President Donald Trump has promised to stop the ongoing spiralling down of the U.S. coal industry. We discuss the origins of the decline and assess the effects of policy interventions by the Trump administration. We find that, with fierce competition from natural gas and renewables, a further decrease of coal consumption must be expected by the old and inefficient U.S. coal-fired electricity generation fleet. By contrast, we consider the overly optimistic (for coal producers) view of the U.S. Energy Information Agency, and test whether the tide for the U.S. coal industry could turn as a result of three potential support measures: (i) revoking the Clean Power Plan (CPP); (ii) facilitating access to the booming Asian market; and (iii) enhanced support for Carbon Capture, Transport and Storage (CCTS) technology. We investigate the short-term and long-term effects on U.S. coal production using a comprehensive partial equilibrium model of the world steam coal market, COALMOD-World (Holz, Haftendorn, Mendelevitch, & von Hirschhausen, 2016). We find that revoking the CPP could stop the downward trend of steam coal consumption in the U.S., but even allowing for additional exports, will not lead to a return of U.S. coal production to the levels of the 2000s, that is, over 900?Mt per year. When global steam coal use is aligned with the 2°C climate target, U.S. steam coal production drops to around 100?Mt per year by 2030 and below 50?Mt by 2050, even if CCTS is available and exports via the U.S. West Coast is possible.

Key policy insights

• Declining U.S. coal use is primarily caused by competition from natural gas and renewables not by environmental regulation of the coal sector.

• Without substantial policy support, U.S. coal-fired generation capacity will continue to decline rapidly.

• Revoking the Clean Power Plan will lead to about one eighth higher U.S. coal production in the next years.

• Carbon Capture, Transport and Storage does not prevent the rapid decline of coal use required under stringent climate policy.

• Even in the most extreme pro-coal scenarios with additional export possibilities, U.S. coal production will not return to its pre-2010 levels.

  相似文献   

Forest fire,bank strength and channel instability: the ‘unusual’ response of Fishtrap Creek,British Columbia     

B.C. Eaton  R.D. Moore  T.R. Giles 《地球表面变化过程与地形》2010,35(10):1167-1183

In August 2003, the McLure forest fire burned 62% of the drainage basin of Fishtrap Creek. Streamflow has been measured there since the early 1970s, and suspended sediment concentration and channel morphology have been monitored since the fire. Although the short post‐fire period (four years) limits our ability to draw firm conclusions about streamflow changes, there has been no obvious increase in peak flows since the fire. However, the total runoff during the freshet period does appear to have increased and the onset of snowmelt appears to occur about two weeks earlier than it did prior to the fire. Suspended sediment records from Fishtrap Creek and from an unburnt reference stream nearby are similar, suggesting that the burnt areas have remained relatively stable and that the sediment supply to Fishtrap Creek has not been dramatically altered. In contrast, the stream channel morphology has changed, widening by over 100% of the original width in some places and transforming from a laterally stable plane‐bed morphology to a laterally active riffle‐pool morphology. The timing and magnitude of the observed morphologic changes are consistent with the predicted decline in bank strength due to root decay, implying that the observed changes are associated with an internal instability associated with changes to the stream boundaries, rather than with the more typically reported externally driven instabilities caused by changes in streamflow or sediment supply. This delayed response in the absence of large changes in streamflow or sediment supply, while ‘unusual’ in that it has not been documented in the previous literature, may be a common mode of response, particularly in wat'ersheds with nival flow regimes. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

太阳能海水淡化技术   总被引：6，自引：0，他引：6  

苏润西 《海洋技术学报》2002,21(4):27-32

文章论述应用太阳能集热和太阳能光伏发电系统进行蒸馏淡化和膜法淡化的海水淡化方法。与传统动力源和热源相比 ,太阳能具有安全、环保等优点 ,将太阳能采集与脱盐工艺两个系统结合是一种可持续发展的海水淡化技术  相似文献   

稠油汽驱电位法动态监测技术   总被引：4，自引：0，他引：4  

牛建军  张晓培  杜立志 《吉林大学学报(地球科学版)》2008,38(5):887-891,898

通过电极电位模型储层电阻率变化量与地表电位变化量之间的关系,采用电位测量方法进行地下储层中稠油运移规律的动态监测。在新疆某油田"稠油油藏汽驱试验"项目中进行该方法的试验,利用汽驱过程中监测到的电位场增量变化特征推断汽驱推进方向及波及范围,根据电位相对变化量值对汽驱作用效果进行区块划分,电位变化量相对大的区块汽驱作用明显,反映该区块的采油产量较高。  相似文献   

泥质薄夹层不同参数对油砂SAGD 开发效果的影响     

孔令晓  齐梅  张帅超  刘鹏程 《现代地质》2018,32(3):537

泥质夹层对油砂SAGD的开发效果具有一定影响。以加拿大麦凯河某区块为研究对象,利用数值模拟手段,对位于注入井上方和注采井间的泥质薄夹层进行表征,模拟对比了泥质薄夹层的位置、延展长度、渗透率、厚度以及条数对SAGD开发效果的影响,得到了油砂SAGD开发的泥质薄夹层的临界参数。研究表明,泥质薄夹层位于注入井上方时对SAGD开发效果影响较小,位于注采井间时有不利影响,且越靠近生产井,蒸汽腔发育越晚,累产油量越低。注采井间泥质薄夹层超过7条、延展长度超过20 m时蒸汽腔几乎不发育,而渗透率与厚度对SAGD开发效果影响不明显。因此油砂SAGD布井时注采井间应尽量避开泥质薄夹层,从而有效降低泥质薄夹层对SAGD的影响。该研究结果,对于指导油砂SAGD部署、规避地质风险、实现SAGD高效开发具有重要指导意义。  相似文献   

氢化物发生原子荧光光谱法测定氢氧化铟中砷含量     

韦刚  周素莲  黄肇敏  宫辛玲 《矿产与地质》2016,(2):294-296

文章对氢化物发生原子荧光光谱法测量氢氧化铟中砷含量的分析方法进行了研究,采用硫酸联胺把五价砷预还原成三价砷,利用三氯化砷的挥发性,经蒸馏分离砷,消除了基体铟干扰。方法线性范围为2ng/mL~70ng/mL,检测下限为2ng/mL,加标回收率为96%~113%,实际样品分析相对标准偏差为4.57%(n=5)。本方法与等离子体发射光谱法、DDTC-Ag分光光度法的分析数据吻合。  相似文献   

共沸蒸馏法制备电气石超细粉末   总被引：1，自引：0，他引：1       下载免费PDF全文

瞿金蓉胡明安  陈敬中 《岩石矿物学杂志》2003,22(4):401-404

分别以水和正丁醇为研磨介质，得到电气石超细粉末的液相悬浮体，利用水和正丁醇可以形成共沸物的特点，分别采用直接加热和共沸蒸馏法脱分散介质干燥悬浮体制备电气石超细粉末。透射电镜分析结果表明，直接加热脱去水或正丁醇会使电气石超细颗粒发生硬团聚，而共沸蒸馏法则可有效防止硬团聚的产生；拉曼光谱结果表明，共沸蒸馏法制备的电气石粉末表面存在O—H和C—H键，说明正丁醇在颗粒表面为化学吸附，而直接干燥法得到的电气石粉末表面则没有；X射线粉晶衍射结果表明，研磨过程降低了粉末衍射峰的强度，但直接加热干燥和共沸蒸馏干燥均未破坏电气石的晶格结构。正丁醇中的丁氧基在共沸蒸馏过程中在电气石颗粒表面可取代羟基，产生化学吸附，能有效防止液桥的产生，阻止干燥过程中超细粉末的硬团聚。  相似文献   

稠油蒸汽热采区声波资料异常现象的物理解释及应用          下载免费PDF全文

赵克超  陶果  王克杰 《地球物理学进展》2007,22(2):502-507

针对稠油蒸汽热采区常见的声波资料异常现象, 根据双相多孔介质声波传播理论及相关实验结果，对于这一特殊的声波测井响应特征进行了解释，认为注入蒸汽的影响导致了纵波速度的低异常及幅度的强衰减, 而使声波测井资料显现出异常高时差值或出现“跳变”现象.据此总结了利用声波资料评价蒸汽波及范围与蒸汽前缘的解释方法，并进行了多井评价实验, 取得了满意结果.同时，也为利用孔隙介质弹性波动理论评价地下蒸汽分布范围的适用性提供了新的现场实际例证.  相似文献