Modified-cold induced aggregation microextraction based on ionic liquid and fibre optic-linear array detection spectrophotometric determination of palladium in saline solutions

In this research, a novel microextraction technique based on ionic liquids (ILs) termed in modified-cold induced aggregation microextraction (M-CIAME) was used for determination of palladium in saline solution. 1-(2-pyridylazo)-2-naphtol (PAN) was chosen as the complexing agent. Analysis was carried out using fibre optic-linear array detection spectrophotometric method which is suitable for analyte determination after microextraction. M-CIAME is based on phase separation phenomenon of ionic liquids in aqueous solutions. This method is simple and rapid for extraction and preconcentration of metal ions from water samples. It can be applied for the sample solutions containing much higher concentrations of salt, in comparison with CIAME (cold induced aggregation microextraction). Furthermore, this technique is much safer in comparison with other microextraction techniques in which organic solvent is used as the extraction solvent. Some effective parameters on extraction and complex formation such as amount of IL, salt effect, pH, concentration of the chelating agent and the other parameters were optimised. Under the optimum conditions, the limit of detection (LOD) and repeatability, expressed as relative standard deviation (n?=?5) for 20?ng?mL^?1 of palladium were 0.4?ng?mL^?1 and 2.23%, respectively. The extraction percentage was 86%.     

内蒙古准苏吉花铜钼矿床稀土元素特征及对成矿作用的约束

准苏吉花高-中温热液脉型铜钼矿床是近年来中蒙边境新发现的众多中型铜钼矿床之一,矿体主要赋存在二叠纪花岗闪长岩中,仅少量产于宝力高庙组变质粉砂岩中,多呈透镜状产出,具尖灭再现现象。矿床稀土元素组成特征表明:花岗闪长岩和闪长岩脉稀土配分模式相似,表现为强负Eu异常和极弱或无负Ce异常,为同源岩浆演化的产物。变质粉砂岩稀土组成与岩浆岩截然不同。辉钼矿矿石稀土元素组成大致可分为两组:一组矿石表现为明显的负Eu异常,Ce表现为由弱异常过渡为无异常的特征,与矿区花岗闪长岩稀土组成相似;另外一组矿石表现为弱负Eu异常和极弱负Ce异常,介于花岗闪长岩与变质粉砂岩稀土元素组成之间,暗示成矿过程中岩浆热液与地层之间发生了水/岩交换。说明区内成矿物质一部分来源于花岗闪长岩,另一部分来源于宝力高庙组变质粉砂岩。矿石δEu值指示矿石沉淀于高温、低氧的相对还原环境。     

在离子液体[BMIm][BF4]中电沉积光亮金镀层

在离子液体1-丁基-3-甲基咪唑四氟硼酸盐（[BMIm][BF₄]）中以HAuCl₄·3H₂O为主盐、通过添加5,5-二甲基乙内酰脲（DMH）和胞嘧啶可得到色泽光亮、厚度达1.5 μm的金镀层,沉积过程中阴极电流效率可达到100%。SEM和XRD测试结果表明,DMH和胞嘧啶具有细化晶粒、平整镀层的作用。电化学测试结果表明,DMH可分别与Au³⁺、Au⁺形成配合物Au（DMH）₄^-、Au（DMH）₂^-,抑制了还原过程的表面转化步骤,从而增加了阴极极化,起到光亮镀层、细化晶粒的作用;胞嘧啶可在金核表面吸附,从而可以进一步光亮镀层、细化晶粒,与DMH有协同作用。循环伏安测试研究了镀液的电化学行为,研究表明在此体系中Au³⁺的还原为两步还原过程,分别为Au³⁺→ Au⁺和Au⁺→ Au。此外DMH和胞嘧啶的添加不会带来副反应。     

母岩高铀离子型稀土矿采区的放射性污染风险浅析

铀与稀土元素同属大离子亲石元素,尤其与钇组稀土关系更密切,因此南岭高铀花岗岩往往同时是铀和离子型重稀土矿床的成矿母岩。国内外研究资料表明,高铀花岗岩中的铀主要以原生铀的形式存在于晶质铀矿中,在强烈风化过程中大部分发生活化转移,而采矿活动对此有显著促进作用;国外众多含铀湿地的发现及其研究资料表明,山区湿地是铀的"高效过滤器"和"沉淀池",花岗岩风化转移到水体中的微量铀经长期累积,可在湿地富有机质土壤和沉积物中富集至(3000~4000)×10^-6,而采矿和农垦活动可将湿地经几千年累积富集起来的铀释放到居民的生活环境中,因而被视为是一种环境风险。因此建议加强母岩高铀离子型稀土矿区的湿地放射性调查和环境保护,以保障湿地对重金属的天然过滤功能,避免湿地束缚铀的释放,这对保护矿区水质和生态环境都具有重要意义。     

A self-assembled deoxyribonucleic acid concatemer for sensitive detection of single nucleotide polymorphism

Polymerase-free and label-free strategies for DNA detection have shown excellent sensitivity and specificity in various biological samples. Herein, we propose a method for single nucleotide polymorphism (SNP) detection by using self-assembled DNA concatemers. Capture probes, bound to magnetic beads, can joint mediator probes by T4 DNA ligase in the presence of target DNA that is complementary to the capture probe and mediator probe. The mediator probes trigger self-assembly of two auxiliary probes on magnetic beads to form DNA concatemers. Separated by a magnetic rack, the double-stranded concatemers on beads can recruit a great amount of SYBR Green I and eventually result in amplified fluorescent signals. In comparison with reported methods for SNP detection, the concatemer-based approach has significant advantages of low background, simplicity, and ultrasensitivity, making it as a convenient platform for clinical applications. As a proof of concept, BRAF^T1799A oncogene mutation, a SNP involved in diverse human cancers, was used as a model target. The developed approach using a fluorescent intercalator can detect as low as 0.1 fM target BRAF^T1799A DNA, which is better than those previously published methods for SNP detection. This method is robust and can be used directly to measure the BRAF^T1799A DNA in complex human serum with excellent recovery (94–103%). It is expected that this assay principle can be directed toward other SNP genes by simply changing the mediator probe and auxiliary probes.     

Features of deposit formation from 1,3-butadiene over Pd catalysts

Formation of carbonaceous deposits from 1,3-butadiene has been investigated over a group of Pd catalysts. Hydrogen generated in decomposition of diene at 473–523 K participates in diene hydrogenation, resulting in the formation ofn-butenes. XRD measurements have confirmed formation of dissolved carbon (PdC_x) phase. DRIFT measurements over 0.06 wt.%Pd/γ-Al₂O₃ have revealed bands at 1575 and 1464 cm⁻¹, suggesting formation of carboxylate structures. Selectivity of the competitive hydrogenation in 1,3-butadiene and propene mixture R(BD)/R(Pr) has been measured on “fresh” and poisoned samples. Accumulation of deposits has decreased the R(BD)/R(Pr) ratio. The results have been interpreted by transport hindrance and a greater prevalence of non-selective low coordination sites on the poisoned surface. Measurements over Pd, Cu, Pt and Rh catalysts have shown that the highn-butane selectivity over Pt and Rh is also accompanied with low R(BD)/R(Pr) values, suggesting that thermodynamic and mechanistic factors are not entirely separable. Dedicated to Professor Pál Tétényi on the occasion of his 70th birthday     

北方岩溶矿床水文地质图编制理论和方法

以岩溶水系统理论为基础，将矿区富水性条件，矿井突水条件和矿井水实际资料，有机地结合起来，进行量化、分区，以新颖，直观的方法表现在图上，使图件具有很强的实用性。     

江西大布铀矿床溶浸地质条件及溶浸方法研究

围绕溶浸采矿这个主题 ,从岩、矿石的物质成分 ,矿石结构构造 ,铀的存在形式 ,岩、矿石物理力学参数 ,矿体形态、产状、规模及矿床水文地质等诸多方面阐述了大布铀矿床溶浸的天然地质条件 ,并通过一系列矿石铀浸出工艺试验 ,获得大量溶浸工艺参数 ,提出大布铀矿床以原地破碎浸出辅以堆浸为最佳采矿方案。     

胶东一个新发现金矿床--辉寨金矿床成矿特征研究

研究了胶东地区新发现的辉寨金矿床,依据围岩蚀变分带特征,成矿热液组分、成矿温度、氢氧同位素、Rb-Sr等时线数据等,该矿床为产于黄铁绢英岩中的蚀变岩型金矿床,由此扩大了该区找金前景.