Feldspar multi-elevated-temperature post-IR IRSL dating of the Wulanmulun Paleolithic site and its implication     

《Quaternary Geochronology》2015

The Wulanmulun site found in 2010 is an important Paleolithic site in Ordos (China), from which lots of stone and bone artifacts and mammalian fossils have been recovered. It was previously dated by radiocarbon and optically stimulated luminescence (OSL) techniques on quartz. To further confirm the reliability of the chronology constructed based on OSL ages and test the applicability of the recently developed pIRIR procedure on sediments from northern China, twenty-four sediment samples (including eolian, lacustrine and fluvio-eolian sands) from the site were determined using the multi-elevated-temperature post-IR IRSL (MET-pIRIR or pIRIR) procedure on potassium feldspar. The results show that the studied samples have two MET-pIRIR D_e preheat plateaus (280–320 and 340–360 °C), and the bleaching rates of the luminescence signals are associated with sample ages and stimulation temperatures. All the pIRIR ages (7–155 ka) corrected for anomalous fading and residual dose obtained after solar bleaching for 15 h are larger than the corresponding quartz OSL ages (4–66 ka) previously determined, even for the young eolian samples (<10 ka). But the corrected IRSL(50 °C) ages (6–85 ka) are broadly consistent with the quartz ages. It appears that the IRSL(50 °C) ages are more reliable, although this contradicts the previously results obtained by other people. On the other hand, we also obtained an extended age plateau between the stimulation temperatures of 50 and 290 °C in the plot of age versus stimulation temperature (A-T plot) by subtracting different residual doses obtained after different bleaching times. The reliability of the plateau ages requires further investigation. For the sediment samples from this site, quartz should be more suitable for dating than K-feldspar, and the quartz OSL ages of 50–65 ka for its cultural layer should be reliable.  相似文献   

野外电位溶出法测铜新探索     

杨文赋  何之华  覃常福 《云南地质》2009,28(3):317-321

溶液中加入氧化剂（高锰酸钾）,氧化电极表面的金属铜形成铜离子进入溶液中,金属氧化溶出时间与溶液中的金属离子的浓度成正比,峰值与溶出时间成正比,因此峰高与溶液中金属离子浓度成正比,以此测定溶液中铜离子的浓度。  相似文献   

Biological effects of anthropogenic salt-load on the aquatic Fauna: A synthesis of 17 years of biological survey on the rivers Werra and Weser     

Jürgen Bäthe  Eckhard Coring 《Limnologica》2011,41(2):125-133

The reduction and the smoothened amplitudes of the chloride concentrations since 2000 have resulted in a gradual positive development of the aquatic fauna in the River Werra. In the salinized section of the river increasing species numbers have been determined along the salinity gradient, which shows maximum chloride concentrations of about 2500 mg/l, maximum potash concentrations at approximately 200 mg/l, and magnesia concentrations peaked at 320 mg/l. As an immediate consequence of the reduction in salt concentration the immigration of various caddis fly species into the lower River Werra was observed. The Number of taxa per sample rose from 5 to more than 30 in the lower Werra region. Changes in species-richness could be seen more frequently in river sections where chloride concentrations fluctuated around 1500 mg/l.  相似文献   

硫酸钾镁肥防结块剂的开发研究   总被引：1，自引：0，他引：1       下载免费PDF全文

孙刚  王雪萍 《盐湖研究》2009,17(3):60-62

分析了青海中信国安科技发展有限公司生产的"国安"牌硫酸钾镁肥产品在生产和运输中产生的结块现象,针对硫酸钾镁肥产品产生结块的原因,开发研制了一种主要成分为阴离子表面活性剂(分子的活性部分有一个带负电荷的离子如磺酸盐、烷基芳基磺酸盐、烷基磺酸盐和脂肪酸铵盐等)的防结块剂产品。  相似文献   

Effect of water quality on the leaching of potassium from sandy soil   总被引：1，自引：0，他引：1  

Z. Kolahchi  M. Jalali   《Journal of Arid Environments》2007,68(4):624-639

When potassium (K⁺) fertilizers are applied to soil, K⁺ is subject to displacement through the soil profile. More generally, the application of K⁺ fertilizers to sandy soils with low clay content and small buffer capacity, in which K⁺ does not interact strongly with the soil matrix, results in localized increases in K⁺ concentration in the soil solution. Losses of K⁺ depend on the concentration of calcium (Ca²⁺) as a competing ion in the leaching water and the amount of water that passes through the soil. In this study, we examined the adsorption and movement of applied K⁺ in columns of sandy soil. Glass tubes, 4.8 cm in diameter and 40 cm in length, were packed with either native soil or Ca²⁺-saturated soil. The resulting 10-cm-long column of soil had a bulk density of 1.65 g cm⁻³. Native soil was leached with distilled water and CaCl₂ solutions of various concentrations. In the Ca²⁺-saturated soil, a pulse of K⁺ was leached with CaCl₂ solutions of various concentrations or distilled water. Increasing the CaCl₂ concentration from 3 to 15 mm resulted in earlier breakthrough, a higher peak concentration of K⁺, and greater amounts of leached K⁺. The breakthrough curve for K⁺, when leached with distilled water, showed very low concentrations and was more delayed than the other treatments. In Ca²⁺-saturated soil, the amount of K⁺ leached increased as Ca²⁺ concentration increased, with up to 54% of the added pulse K⁺ being removed from 10 pore volumes (Pv) (387 mm) of 15 mm CaCl₂. The presence of Ca²⁺ in irrigation water and soil minerals able to release Ca²⁺ is important in determining the amount of K⁺ leached from soils. Large amounts of K⁺ are leached from soils in areas where crops are irrigated with water that contains significant concentrations of Ca²⁺ and other cations.  相似文献   

我国积极破解钾盐矿资源短缺迷局   总被引：2，自引：0，他引：2       下载免费PDF全文

庾莉萍 《盐湖研究》2007,15(4):49-55

介绍了钾肥的应用范围,阐述了我国钾盐的生产情况、需求空间和对进口的依赖程度,重点介绍了我国主要的钾盐资源和泰国、老挝、俄罗斯等周边国家的钾盐资源。最后提出了要充分利用国内外"两种资源、两个市场",建立起我国强有力的钾肥资源保障体系,保障我国农村的可持续发展。  相似文献   

硫酸铁钾转化法制取硫酸钾     

熊国宣  马建国  彭道峰  刘云海 《华东地质学院学报》2000,23(1):52-55

以钛白副产绿矾和氯化钾为原料 ,采取硫酸铁钾转化法制备硫酸钾。该工艺既具有反应时间短、操作控制方便、产品质量符合国标要求等优点 ,又治理了钛白粉厂环境污染 ;既具有一定的经济效益 ,又有一定的社会效益。  相似文献   

氯化钾与硫酸钠制硫酸钾工艺的优化          下载免费PDF全文

屠兰英  赵启文 《盐湖研究》2000,8(3):32-39

根据 K+ ,Na+∥ Cl-,SO4 2 -— H2 O体系相图 ,提出了氯化钾与芒硝制备硫酸钾工艺中新的工业化生产循环和解决钾芒硝富集问题的具体方案 ,取得良好效果。  相似文献   

Chloride in precipitation and streamwater for the upland catchment of river severn,mid-wales; some consequences for hydrochemical models     

Colin Neal  Nils Christophersen  Richard Neale  Christopher J. Smith  Paul G. Whitehead  Brian Reynolds 《水文研究》1988,2(2):155-165

Variations in the concentration of Cl in rainfall and stream runoff are presented for two catchments in the Hafren forest of mid-Wales, Great Britain. Despite the large fluctuations in rainfall concentrations, Cl in the streamwater remains relatively constant. Using the two-reservoir Birkenes model, an attempt was made to simulate observed Cl in streamwater. The original model was unable to reproduce the observations and several modifications are suggested to provide better simulations. The resulting model is not the only one capable of reproducing the observations; other hydrochemical models will most probably also achieve this although emphasis will in each case be placed on different aspects. In this paper, it is suggested that the stochastic properties of water movement and chemical processes can account for the streamwater chemistry responses observed. On the catchment scale these processes will lead to an apparently deterministic behaviour that may well be described by simple relationships.  相似文献   

青海省柴达木地区钾肥生产企业粉尘、噪声主要职业病危害的调查分析     

萨如丽 《盐湖研究》2018,26(3):64-69

青海是我国资源较为丰富的省份,钾盐资源的开发及钾肥生产在国内占有重要地位。随着青海高原地区盐湖钾肥产业的迅速发展,相关部门对该行业职业卫生、职业病防治工作日渐重视。通过大量的现场数据收集、整理,对青海高原地区盐湖钾肥行业作业人员面临的职业病危害因素、健康安全等相关问题进行了总结和分析,提出了有针对性的防范措施。  相似文献