黄土醋酸淋溶实验及其碳酸盐组分的地球化学特征   总被引：5，自引：0，他引：5  

刘连文  王洪涛  陈旸  陈骏 《岩石矿物学杂志》2002,21(1):69-73

选择性的化学淋溶实验 ,广泛用于沉积物的地球化学研究中。通过对比 1mol/L的盐酸和醋酸两种溶剂对黄土和古土壤的淋溶效果 ,发现 1mol/L的醋酸能选择性淋溶黄土和古土壤中碳酸盐组分 ,对硅酸盐、铁的氧化物等影响很小。在确定溶剂后 ,以 1mol/L醋酸溶液选择性淋溶了洛川剖面 4 3个黄土和古土壤样品 ,通过分析淋溶液的组成 ,得出黄土和古土壤中碳酸盐组分的平均成分 (wB)为 :MgO 1.71% ,MnO 670× 10 - 6 ,Sr 4 90× 10 - 6 。淋溶结果较好地反映了黄土-古土壤剖面的风化成壤程度 ,其中醋酸淋溶液中MnO含量能更好地反映当时的古气候信息。  相似文献   

钾长石粉酸浸除铁的实验研究   总被引：8，自引：1，他引：8  

郑骥  马鸿文等 《地球科学》2001,26(6):657-660

在利用钾长石粉合成沸石分子筛和制取碳酸钾技术中，铁的存在会降低沸石的白度。对北京平谷、天津蓟县、内蒙白云鄂博三地钾长石粉进行硫酸酸浸除铁实验，获得最大铁浸出率分别为88．6％、93．2％和64．6％，且前两地钾长石粉中铁的浸出行为相似，酸浸除铁效果均优于白云鄂博钾长石粉。采用正交实验法研究硫酸浓度、酸浸温度和时间对除铁效果的影响，表明三者对不同地区钾长石粉酸浸除铁效果的影响程度各不相同。钾长石酸浸除铁反应开始时，铁的溶解极快，反应速率主要由化学反应控制；其后溶解相对缓慢，反应速率则由扩散作用控制。  相似文献   

峨眉山1998年8月和12月采集雨水化学组成的对比研究   总被引：5，自引：0，他引：5  

柳泽文孝  贾疏源  益田晴惠  杨慧东  万新南  中屋真司  北田奈绪子  伊藤浩子 《地质灾害与环境保护》2001,12(4):17-20

为了查明峨眉山地区雨水污染物的来源，从1998年4月开始，每月从22个采样点收集雨水样，对1998年8月和12月收集雨水的化学成分进行对比并讨论。  相似文献   

酸性土壤中20种元素有效态浸提体系浅析   总被引：8，自引：4，他引：8  

李锡坤  李鉴伦  洪翊  冯超  何平 《岩矿测试》2001,20(3):167-173

通过对酸性土壤中Cu、Pb、Zn、Co、Ni、Fe、Mn、Cd、K、Na、Ca、Mg、Si、P、S、Mo、F、Se、As、Hg20种元素有效态的浸提与测定，拟定了一个操作条件宽松、质量稳定，能满足区域调查需要的浸提体系和分析方案。该分析配套方案对20种元素的检出限在（0.0001～4.9）×10  相似文献   

Variations in chemical compositions of the eolian dust in Chinese Loess Plateau over the past 2.5 Ma and chemical weathering in the Asian inland   总被引：5，自引：0，他引：5  

CHEN Jun  LIU Lianwen  JI Junfeng  YANG Jiedong  CHEN Yang 《中国科学D辑(英文版)》2001,44(5):403-413

Major and trace elements as well as strontium isotopic composition have been analyzed on the acid-insoluble (AI) phase of the loess-paleosol sequence from Luochuan, Shaanxi Province, China. Results show that the chemical composition of AI phase of loess and paleosols is distinctive to the average composition of upper continental crust (UCC), characterized by depletion of mobile elements Na, Ca and Sr. The distribution pattern of elements in AI phase reveals that initial dust, derived from a vast area of Asian inland, has suffered from Na- and Ca-removed chemical weathering compared to UCC. Some geochemical parameters (such as CIA values, Na/K, Rb/Sr and⁸⁷Sr/⁸⁶Sr ratios) display a regular variation and evolution, reflecting that the chemical weathering in the source region of loess deposits has decreased gradually since 2.5 Ma with the general increase of global ice volume. This coincidence reflects that the aridity of Asian inland since the Quaternary is a possible regional response to the global climate change.  相似文献   

Two-dimensional modelling of some CFC replacement compounds     

Oliver Wild  Oliver V. Rattigan  Roderic L. Jones  John A. Pyle  R. Anthony Cox 《Journal of Atmospheric Chemistry》1996,25(2):167-199

The Cambridge 2-D Eulerian model has been used to study the potential atmospheric distributions and lifetimes of a number of CFC replacement compounds and their degradation products. The study has focused on HFC 134a and HCFCs 123, 141b and 142b and the major products formed by their atmospheric degradation. The loss of these compounds and their products by hydroxyl radical attack, photolysis and in-cloud hydrolysis have been investigated. The study has shown that HCFCs 141b and 142b have sufficiently long lifetimes to enter the stratosphere in significant quantities, where degradation leads to an increase in the total stratospheric chlorine concentration. The study has also highlighted areas where further experimental work would be valuable, in particular characterisation of the product channels for the degradation reactions and determination of the removal rates of the products in the aqueous phase.  相似文献   

区域酸性沉降的数值研究 I. 模式   总被引：17，自引：3，他引：17  

王体健  李宗恺  南方 《大气科学》1996,20(5):606-614

建立了一个三维时变的欧拉型区域酸性污染物沉降模式，模式包括源排放、平流输送、湍流扩散、干沉积、气相化学、液相化学及湿清除等六大部分。考虑到计算条件的承受能力和应用性的要求，在把握酸沉降形成的关键过程的前提下，合理地简化设计模式。相对于国内已有的工作，本模式在干沉积、气相化学、液相化学和湿清除等方面均有所改进。  相似文献   

三元体系RECl_3（RE＝Dy，Yb）－HOAc－H_2O（30℃）的研究     

李亚红  王惠  王林溪 《盐湖研究》1996,(Z1)

测定了三元体系ＲＥＣｌ３（ＲＥ＝Ｄｙ，Ｙｂ）－ＨＯＡｃ－Ｈ２Ｏ（３０℃）的平衡态的溶度数据并绘制了相应的溶度图。在两个体系中分别得到了ＤｙＣｌ３·６Ｈ２Ｏ和ＹｂＣｌ３·６Ｈ２Ｏ两种固相。依据ＨＯＡｃ对ＤｙＣｌ３·６Ｈ２Ｏ和ＹｂＣｌ３·６Ｈ２Ｏ有盐抗作用这一结论得到了一种制备ＤｙＣｌ３·６Ｈ２Ｏ和ＹｂＣｌ３·６Ｈ２Ｏ的ＨＣｌ—ＨＯＡｃ法。同时，在分析测定酸的重量百分浓度时，利用“差减法”得到了Ｈ＋的准确含量。  相似文献   

Covariations in oceanic dimethyl sulfide,its oxidation products and rain acidity at Amsterdam Island in the Southern Indian Ocean   总被引：5，自引：0，他引：5  

B. C. Nguyen  N. Mihalopoulos  J. P. Putaud  A. Gaudry  L. Gallet  W. C. Keene  J. N. Galloway 《Journal of Atmospheric Chemistry》1992,15(1):39-53

Simultaneous measurements of rain acidity and dimethyl sulfide (DMS) at the ocean surface and in the atmosphere were performed at Amsterdam Island over a 4 year period. During the last 2 years, measurements of sulfur dioxide (SO₂) in the atmosphere and of methane sulfonic acid (MSA) and non-sea-salt-sulfate (nss-SO₄ ^2-) in rainwater were also performed. Covariations are observed between the oceanic and atmospheric DMS concentrations, atmospheric SO₂ concentrations, wet deposition of MSA, nss-SO₄ ^2-, and rain acidity. A comparable summer to winter ratio of DMS and SO₂ in the atmosphere and MSA in precipitation were also observed. From the chemical composition of precipitation we estimate that DMS oxidation products contribute approximately 40% of the rain acidity. If we consider the acidity in excess, then DMS oxidation products contribute about 55%.  相似文献   

等离子体发射光谱法分析毒砂单矿物     

曾惠芳 《岩矿测试》1992,11(3):211-216

研究了大孔膦酸树脂对毒砂中主、次和痕量元素的吸附行为及洗脱条件,结合巯基棉和TBP柱分离技术,建立了两个分离流程。在J-A1160型多道直读光谱仪上实现了毒砂单矿物中包括主量元素Fe和As在内的20个元素测定。主量元素As和Fe的相对标准偏差(n为5～10)分别为1.03％和0.9％,其它元素在5％～11％范围。流程经实际试样分析验证,结果与化学法相符。  相似文献