桂西沉积型锂矿资源潜力分析

桂西地区是我国重要的铝土矿产区,共、伴生有镓、钪等多种稀有、稀土元素.为探讨其锂矿资源潜力,在对区域地质背景、锂地球化学异常、矿产分布等综合分析的基础上,对比了以右江断裂为界的南北两侧锂异常特征和物源差异：南侧锂异常可能主要源于局限台地,异常与二叠系合山组吻合;北侧锂异常则与石炭系尧云岭组更加密切,引起异常物质可能主要源于扬子地台碳酸盐岩风化.初步认为桂西锂矿勘查应优先在右江断裂以北展开,以碳酸盐黏土型锂矿为主要目标,以Li、Be、Fe₂O₃等综合异常区的碳酸盐岩古风化壳,尤其是石炭系尧云岭组和二叠系合山组中的古风化壳为主要目标层位.     

高纬日侧电离层离子上行的地磁活动依赖性研究

本文对比分析了太阳活动高、低年期间高纬日侧顶部电离层离子上行随地磁活动水平的变化特征.按地磁活动水平,将DMSP卫星在太阳活动高年（2000-2002年,F13和F15）及太阳活动低年（2007-2009年,F13;2007-2010年,F15）期间的SSIES离子漂移速度观测数据分为三组：地磁平静期（Kp<3）,中等地磁扰动期（3 ≤ Kp < 5）和强地磁活动期（Kp ≥ 5）,分别统计分析了高纬日侧顶部电离层离子上行特征的时空分布.对比分析发现：（1）太阳活动低年期间,高纬日侧电离层离子上行发生率以及上行速度峰值均是太阳活动高年的2倍多,而离子上行通量峰值只有高年的1/6-1/4;（2）在相同太阳活动条件下,地磁活动水平对日侧电离层离子上行发生率峰值的影响并不明显,但对离子上行发生率的空间分布有着显著的控制作用：电离层离子上行高发区随地磁活动向低纬度扩展,并在强地磁活动期间呈现饱和的趋势;（3）日侧顶部电离层等离子体似乎存在两个效率相当的上行区域,一个位于极尖/极隙区纬度附近,离子可沿开放磁力线上行进入磁尾;另一个位于晨侧亚极光区附近,离子沿闭合磁力线上行,有可能进入日侧等离子体层边界层.     

Selective Preconcentration of Trace Amounts of Cu(II) With Surface‐Imprinted Multiwalled Carbon Nanotubes

In this study, a new sorbent is synthesized using surface imprinting technique. Cu(II)‐imprinted multiwalled carbon nanotube sorbent (Cu(II)‐IMWCNT) is used as the solid phase in the solid‐phase extraction method. After the preconcentration procedure, Cu(II) ions are determined by high‐resolution continuum source atomic absorption spectrometry. A total of 0.1 mol L^?1 ethylenediaminetetraacetic acid (EDTA) is used to remove Cu(II) ions from the sorbent surface. The optimum experimental conditions for effective preconcentration of Cu(II), parameters such as pH, eluent type and concentration, flow rate, sample volume, sorbent capacity, and selectivity are investigated. The synthesized solid phase is characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The maximum adsorption capacities of Cu(II)‐IMWCNT and non‐imprinted solid phases are 270.3 and 14.3 mg g^?1 at pH 5, respectively. Under optimum experimental conditions for Cu(II) ions, the limit of detection is 0.07 μg L^?1 and preconcentration factor is 40. In addition, it is determined to be reusable without significant decrease in recovery values up to 100 adsorption–desorption cycles. Cu(II)‐IMWCNT have a high stability. To check the accuracy of the developed method, certified reference materials, and water samples are analyzed with satisfactory analytical results.     

Major Ion Geochemistry of Nam Co Lake and its Sources, Tibetan Plateau

The major cations and anions from lake water samples and its sources, including glacier snow, precipitation, stream, and swamp water in the Nam Co basin, central Tibetan Plateau, were studied. The concentrations of the major ions varied significantly in the five environmental matrices. Generally, the mean concentrations of most ions are in the order of lake water > swamp water > stream water > precipitation > snow. Rock weathering is the dominant process controlling the chemical compositions of the stream and swamp waters, with carbonate weathering being the primary source of the dissolved ions. The Nam Co lake water is characterized by high Na⁺ concentration and extremely low Ca²⁺ concentration relative to other ions, resulting from evapoconcentration and chemical precipitation within the lake. Comparison with the water chemistry of other lakes over the Tibetan Plateau indicated that Nam Co is located in a transition area between non-saline lakes and highly saline lakes. The relatively low concentration of total dissolved solids is possibly due to the abundant inflow of glacial meltwater and relatively high annual precipitation.     

离子色谱法测定牛皮纸样袋中海底沉积物的氯量

对离子色谱法测定氯含量常用的IonPac AS14A保护柱和新型IonPac AS23分析柱进行对比实验,选择了IonPac AS23柱作为分析柱。解决了碳酸盐对氯离子测定的干扰,优化色谱条件,同时分析牛皮纸样袋中海底沉积物中的氯含量测定结果偏低的原因,拟定了准确测定牛皮纸样袋中海底沉积物中氯含量的方法。通过测定国家一级标准物质中氯含量,结果与标准值相符,其相对标准偏差≤2.66%。     

AG MP-1阴离子交换树脂元素分离方法研究

在用多接收器等离子体质谱仪（MC—ICP—MS）测定过渡族元素同位素时,需要对待测样品进行分离纯化。目前,人们常用AGMP-1阴离子交换树脂在不同浓度的HCl和HNO,介质中依次分离出Cu,Fe和zn。为详细了解样品中基体元素与AGMP-1阴离子交换树脂的作用以及它们在该树脂中的淋洗过程,根据金属阳离子与Cl^-形成络合物的稳定性及它们与阴离子交换树脂的亲和力,对利用AGMP-1进行Cu和Fe分离过程中基质元素的行为进行了实验研究。结果表明,除Co外,在7mol／LHCl条件下,地质样品中基体元素（包括cr和Ni）能与Cu,Fe进行很好的分离。不同酸度下的实验研究表明,在6mol／LHCl条件下,可以将Cu和Co进行很好的分离。为此提出,对于基质元素含量较少的样品（如硫化物、氧化物、氢氧化物等）,可直接用6mol／LHCl进行样品分离。由于这类样品中K,Na,Ca,Mg,A1等元素含量较低,在Cu被洗脱前已被彻底淋洗,该方法可将Cu和包括Co在内的基质元素进行理想的分离。对于含Co较高的部分硅酸盐等样品,则应先用7mol／LHCl分离出Cu接收液,之后过二遍柱,以6mol／LHCl作淋洗液,去掉Co。建立的分离方法还可应用于Ca,Mg同位素的前期分离纯化     

大洋锰结核氨浸渣脱硫产物处理含镉废水的研究

研究了大洋锰结核氨浸渣脱硫产物去除废水中镉离子的多种影响因素,如接触时间、脱硫产物粒径、溶液pH值、初始镉离子浓度和吸附剂量。并利用X射线粉末衍射(XRD)、场扫描电镜(SEM)、X射线光电子能谱(XPS)对材料和产物进行了表征。结果表明减小脱硫产物粒径、增大吸附剂量等有利于提高去除效果;大洋锰结核氨浸渣脱硫产物去除水中镉离子是基于离子交换反应的原理:MnS+Cd2+→CdS+Mn2+。     

吉林汪清尖晶石橄榄岩包体的矿物化学成分指示意义──上地幔温度史和交代作用

利用电子、离子探针技术对吉林汪清－尖晶石方辉橄榄岩包体的原生和地幔交代矿物进行了详细分析。结果表明：（１）原生矿物强烈亏损玄武质组分，斜方辉石残斑具强烈的成分分带。地质温度计计算结果暗示该地区上地幔经历了一个由大于１２００℃到８５０℃的抬升历史；（２）该包体经历了多期交代作用，交代介质均与寄主玄武岩浆无关。较早一期为隐型交代，交代介质富轻稀土、贫重稀土；较晚一期的交代主要反映在各种交代组合的出现，仅发生在寄主玄武岩喷发之前，交代介质的稀土含量明显高于前一期，这可能与碳酸盐交代作用有关。     

离子色谱法检测饮用水中的草甘膦

建立了离子色谱法直接测定饮用水中草甘膦的分析方法。水样加入抗坏血酸除去余氯,微孔滤膜过滤后直接进样测定。用IonPac AS11-HC阴离子交换柱为分析柱,淋洗液为20 mmol/L KOH溶液,流速为1.00mL/min,进样量100μL进行检测。方法的线性范围0~1.5 mg/L,检出限为0.1 mg/L,加标回收率为95%~106%,相对标准偏差为5.08%~7.09%。方法操作简便快捷,灵敏度高,结果准确可靠。     

Lithium Isotope Composition of Marine Biogenic Carbonates and Related Reference Materials

In this study, the accuracy and the precision corresponding to Li isotopic measurements of low level samples such as marine and coastal carbonates are estimated. To this end, a total of fifty‐four analyses of a Li‐pure reference material (Li7‐N) at concentrations ranging from 1 to 6 ng ml^?1 were first performed. The average δ⁷Li values obtained for solutions with and without chemical purification were 30.3 ± 0.4‰ (2s, n = 19) and 30.2 ± 0.4‰ (2s, n = 36), respectively. These results show that the chosen Li chemical extraction and purification procedure did not induce any significant isotope bias. Two available carbonate reference materials (JCt‐1 and JCp‐1) were analysed, yielding mean δ⁷Li values of 18.0 ± 0.27‰ (2s, n = 6) and 18.8 ± 1.8‰ (2s, n = 9), respectively. Small powder aliquots (< 15 mg) of JCp‐1 displayed significant isotope heterogeneity and we therefore advise favouring JCt‐1 for interlaboratory comparisons. The second part of this study concerns the determination of δ⁷Li value for biogenic carbonate samples. We performed a total of twenty‐nine analyses of seven different tropical coral species grown under controlled and similar conditions (24.0 ± 0.1 °C). Our sample treatment prior to Li extraction involved removal of organic matter before complete dissolution in diluted HCl. Our results show (a) a constant δ⁷Li within each skeleton and between the different species (δ⁷Li = 17.3 ± 0.7‰), and (b) a Li isotope fractionation of ?2‰ compared with inorganic aragonite grown under similar conditions. Comparison with literature data suggests a significant difference between samples living in aquaria and those grown in natural conditions. Finally, we investigate ancient (fossil) carbonate material and foraminifera extracted from marine sedimentary records. Different leaching procedures were tested using various HCl molarities. Results indicate that carbonate preferential dissolution must be carried out at an acid molarity < 0.18 mol l^?1. Possible contamination from silicate minerals can be verified using the Al/Ca ratio, but the threshold value strongly depends on the carbonate δ⁷Li value. When the silicate/carbonate ratio is high in the sediment sample (typically > 2), contamination from silicates cannot be avoided, even at low HCl molarity (? 0.1 mol l^?1). Finally, bulk carbonate and foraminifera extracted from the same core sample exhibited significant discrepancies: δ⁷Li values of foraminifera were more reproducible but were significantly lower. They were also associated with lower Sr/Ca and higher Mn/Ca ratios, suggesting a higher sensitivity to diagenesis, although specific vital effects cannot be fully ruled out.