t-BAMBP/磺化煤油体系萃取溶液中微量铯          下载免费PDF全文

刘泽宇  王斌  杨晋生  范承亮  宝阿敏  黄东方  王舒娅  李波  郑红 《盐湖研究》2019,27(3):75-80

铯作为一种化学性质活泼的碱金属,具有优异的光电性能,在催化、光电、磁流体发电和医药等很多领域应用广泛。本文使用t-BAMBP/磺化煤油体系对溶液中微量铯进行萃取,用盐酸进行反萃。主要考察了萃取剂浓度、O/A(萃取剂油相与溶液水相之比)、碱度、萃取时间、振荡强度、萃取温度、反萃酸的浓度和反萃时间等实验条件。发现最佳正萃条件为萃取剂浓度1 mol/L,O/A相比1∶1,碱度1 mol/L,萃取时间2 min,振荡强度200 r/min,萃取温度为20℃,反萃酸c(HCl)为0.1 mol/L,反萃时间t_2为3 min。  相似文献   

红藻真江篱质粒的发现     

秦松  童顺  崔武  王希华  李亚非  吴光耀  张培军  曾呈奎 《海洋与湖沼》1994,25(4):349-352

于1992年4月一1993年4月，用液氮研磨-苯酚／氯仿抽提-异丙醇沉淀的方法提取青岛沿海产紫菜、真江蓠、龙须菜、海膜4种红藻的总DNA；利用Hoechst－CsCl密度梯度起离心法将叶绿体DNA与核DNA分开。对抽取的叶绿体DNA梯度组分电泳结果表明，真江蓠样品出现质粒的电泳条带。以透射电镜观察到闭会环状DNA图像（周长平均值为4.3×10－7m，约为1．3kb）；分子杂交结果显示，真江蓠质位与其叶绿体DNA之间没有同源性，而与核DNA之间有一定同源性。  相似文献   

HIROSS空调在守时钟房运行中存在的问题及改进     

安卫  刘春侠  王改霞 《时间频率学报》2001,24(2):147-151

钟房环境参数的控制对多铯原子钟的工作状态起着至关重要的作用。对陕西天台钟房改造后加装的两台HIROSS空调的运行情况作一介绍，并分析了HIROSS空调控制的Cs08房间温度变化大的原因，经过对地下室风道的改造，达到了预期的效果。  相似文献   

Sediment yield and runoff frequency of small drainage basins in the Mojave Desert, U.S.A.     

Peter G. Griffiths  Richard Hereford  Robert H. Webb   《Geomorphology》2006,74(1-4):232-244

Sediment yield from small arid basins, particularly in the Mojave Desert, is largely unknown owing to the ephemeral nature of these fluvial systems and long recurrence interval of flow events. We examined 27 reservoirs in the northern and eastern Mojave Desert that trapped sediment from small (< 1 km²) drainage basins on alluvial fans over the past 100 yr, calculated annual sediment yield, and estimated the average recurrence interval (RI) of sediment-depositing flow events. These reservoirs formed where railbeds crossed and blocked channels, causing sediment to be trapped and stored upslope. Deposits are temporally constrained by the date of railway construction (1906–1910), the presence of ¹³⁷Cs in the reservoir profile (post-1952 sediment), and either 1993, when some basins breached during regional flooding, or 2000–2001, when stratigraphic analyses were performed. Reservoir deposits are well stratified at most sites and have distinct fining-upward couplets indicative of discrete episodes of sediment-bearing runoff. Average RI of runoff events for these basins ranges from 2.6 to 7.3 yr and reflects the incidence of either intense or prolonged rainfall; more than half the runoff events occurred before 1963. A period of above-normal precipitation, from 1905 to 1941, may have increased runoff frequency in these basins. Mean sediment yield (9 to 48 tons km^− 2 yr^− 1) is an order of magnitude smaller than sediment yields calculated elsewhere and may be limited by reduced storm intensity, the presence of desert pavement, and shallow gradient of fan surfaces. Sediment yield decreases as drainage area increases, a trend typical of much larger drainage basins where sediment-transport processes constrain sediment yield. Coarse substrate and low-angle slopes of these alluvial fan surfaces likely limit sediment transport capacity through transmission losses and channel storage.  相似文献