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11.
二道沟金矿床中的稀土元素地球化学特征 总被引:2,自引:0,他引:2
通过对未蚀变流纹岩,蚀变流纹岩和金矿石中稀土元素组成及分布模式的研究,表明岩浆热液与以大气降水为来源的地下水相混合后形成的成矿热液中稀土元素具有富集LRE、稀土元素总量低以及Eu具有明显负异常的特征。 相似文献
12.
Surface plasmon resonance (SPR) has been successfully applied for the simple, rapid, and label-free assay of various biomolecules. This assay evaluates a novel wavelength modulation SPR biosensor for the detection of tetanus toxin. The wavelength modulation SPR biosensor is designed based on fixing the incident angle of light and measuring the reflected intensities in the resonance wavelength range spanning 400-800 nm simultaneously. Tetanus toxin (TeNT), one of the most potent toxins known, is synthesized as a 150 kDa single polypeptide chain. The SPR biosensor has been shown to be capable of directly detecting concentration of tetanus toxin as low as 0.028 Lf ml−1. Under selected experimental conditions, the SPR biosensor has a good reproducibility, sensitivity and reversibility. The results illustrate how wavelength modulation SPR biosensor can be used to detect biomolecular interactions. 相似文献
13.
Chi-Chang?HuEmail author Hong-Ru?Chiang Chen-Ching?Wang 《Journal of Solid State Electrochemistry》2003,7(8):477-484
The electrochemical characteristics of ruthenium oxides, formed on Ru-plated Ti electrodes in 0.5 M H2SO4 by potential cycling with different CV upper potential limits (E
SU), were systematically compared. The repeated potential cycling between 0.2 and 0.75 V activated the formation/reduction of
surface Ru oxides with hysteretic behavior. This application of repeated CVs also modified the ability of Ru deposits for
hydrogen adsorption/desorption. An irreducible Ru oxide accumulated on the electrode at potentials more positive than ca.
0.95 V, whose capacitive characteristics are applicable for electrochemical supercapacitors. This irreducible oxide was composed
of an aggregate consisting of Ru in various oxidation states, bridged oxygen, OH and water in a 3D-like structure with a relatively
ordered and compact nature, from the X-ray photoelectron spectroscopic and voltammetric results. The surface reconstruction
of the Ru deposits induced by the repeated potential cycling with E
SU≥0.75 V was clearly observed from the SEM photographs. From the X-ray diffraction patterns, all the anodically formed Ru oxides
showed an amorphous nature. 相似文献
14.
《Electroanalysis》2006,18(11):1081-1089
This paper describes the voltammetric behavior of As(III) at the hanging mercury drop electrode (HMDE) in the presence of sodium diethyl dithiocarbamate (SDDC) and a new voltammetric method for the determination of As(III) at trace levels. The method is based on the adsorptive deposition of a As(III) complex with SDDC at ?0.45 V (vs. Ag/AgCl) on the HMDE in acidic medium of 0.01 mol L?1 HCl (pH 2.0) and its cathodic stripping during the potential scan (100 mV s?1). The linear range for the determination of As(III) in the presence of SDDC (4 μmol L?1) in water samples was between 1 and 10 μg L?1 for a deposition time of 300 s (r=0.994) and between 10 and 100 μg L?1 for a deposition time of 60 s (r=0.999). For the determination of As(III) in dialysis concentrate samples, the linear range was between 5 and 25 μg L?1 for a deposition time of 180 s (r=0.992) and between 10 and 100 μg L?1 for a deposition time of 60 s (r=0.996). Detection limits of 0.3 and 2.2 μg L?1 in water and dialysis concentrate samples were calculated for the method using a deposition time of 300 and 180 s, respectively. Recovery values between 93.0 and 110.0% for As(III) added to deionized, mineral, seawater (synthetic and real) and dialysis concentrate samples prove the satisfactory accuracy and applicability of the procedure. 相似文献
15.
在西北季节冻土区广泛分布着盐渍土,其在空间分布上连续性差,工程性质极其不稳定;且浅层盐渍土受冻融作用的反复影响,其力学性质长期处于动态的变化之中,给工程设计与建设带来了极大的挑战.鉴于此,通过压缩试验及无侧限抗压强度试验,研究稻壳灰对盐渍土的改良效果.结果表明,稻壳灰可以显著地改善盐渍土的压缩特性,并提高其无侧限抗压强度,且改良土的压缩系数与抗压强度之间呈现出负相关的线性关系.随着掺灰量和养护龄期的增加,改良土的压缩系数不断减小,无侧限抗压强度呈现出不断增加的趋势,最大可增加4倍左右.以抗压强度损失率为指标对改良土的抗冻性进行了评价,发现改良土的抗冻性随着掺灰量的增加呈现出先增强后减弱的趋势,且在15%的掺灰量时,其抗冻性效果最显著;相对而言,养护龄期对于改良土的抗冻性影响较小. 相似文献
16.
17.
袁峰 《合肥工业大学学报(自然科学版)》1998,(6)
系统地研究了新疆阿尔泰诺尔特地区阿克提什坎金-多金属矿床的微量元素组成特征,并应用Grant等位线方法讨论了热液蚀变作用过程中微量元素的行为。认为在热液蚀变作用过程中,微量元素尤其是Au、As等,活动强烈,围岩为成矿提供了部分物质来源。文章还进行了质量迁移的定量计算。 相似文献
18.
《Arabian Journal of Chemistry》2022,15(4):103712
Although recent decades have witnessed the synthesis of 1,3,4-thiadiazoles via phosphorus POCl3-promoted cyclization reaction, simultaneous access to 2-amino-1,3,4-thiadiazole and 2-amino-1,3,4-oxadiazole analogs remains unexpected and elusive. Herein, a detailed regiocontrolled synthesis of 2-amino-1,3,4-thiadiazoles in good to high yields with good regioselectivities from readily available thiosemicarbazides using POCl3 was disclosed. Meantime, to establish a comprehensive structure–activity relationship, 2-amino-1,3,4-oxadiazole derivatives as single regioisomers were prepared via EDCI·HCl-triggered cyclization of the thiosemicarbazide intermediates. The in vitro anti-influenza assays proved that the selected compounds with the pyrazine/pyridine ring exhibited certain inhibitory activities against influenza A virus strains A/HK/68 (H3N2) and A/PR/8/34 (H1N1) in MDCK cells. Among them, N-(adamantan-1-yl)-5-(5-(azepan-1-yl)pyrazin-2-yl)-1,3,4-thiadiazol-2-amine (4j) was the most active compound, and exhibited favorable activity with EC50 values of 3.5 μM and 7.5 μM, respectively. In addition, the molecular docking results explained the reason why compound 4j had dual inhibitory activity and revealed the reasonable binding mode of this compound with the M2-S31N and M2-WT ion channels. This compound had the potential to be further developed as an anti-influenza drug. 相似文献
19.
作者根据对新疆东天山典型金矿床的沉淀成矿环境、地球化学特征、稳定同位素特征等的系统分析和研究,论证了形成金矿床的硅质流体最初是一种以水为主要溶剂,以溶解态、胶体态氧化硅为主要溶质的高温高压(超临界态)溶液,其来源于地幔,是一种溶解了大量SiO2的地幔流体。而成矿元素主要来源于硅质流体上升运移过程中所经围岩,以致成矿物质来源具异源性。这对研究内生金矿床的成矿机制和成因有着十分重要的意义。 相似文献
20.
渐新统沙二段是济阳坳陷车西地区的主力油层,为了弄清其油气分布和控制因素,综合利用大量的地质和地球物理资料,首次在该段识别出漫湖洪水—风暴重力流沉积.该沉积具有明显的重力流沉积特征,砂岩的成分和结构成熟度均较低,粒度概率图多由悬浮次总体组成,沉积序列可用Bouma序列来描述.在明确了砂体的沉积层位和沉积边界的基础上,描述了漫湖洪水—风暴的沉积特征并建立了沉积模式,系统分析了这个环境下储集性砂体的分布及其油气聚集特征,为车西洼陷的进一步勘探指明了方向. 相似文献