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1.
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   
2.
文章对比分析研究了江西相山铀矿区和非铀矿区稻谷中天然放射性核素U和Th的含量特征。样品分别采自江西省相山铀矿区及远离铀矿区的抚州市郊丘陵水稻种植区。结果表明相山铀矿区稻谷中天然放射性核素U的含量显著高于非铀矿区的稻谷,铀矿区内稻谷中放射性核素U含量平均值是非铀矿区的5.30倍;但铀矿区内稻谷中放射性核素Th的含量却较非铀矿区稻谷含量低,仅为其Th含量的50%。另外,相山铀矿区内稻谷中放射性核素U和Th之间存在较为显著的线性关系,稻谷中放射性核素Th的含量随U含量的增加而升高。铀矿区内稻谷中放射性核素U含量显著高于非铀矿区的原因还有待于进一步深入研究,然而加强该领域的研究对于保证我国区域稻谷质量和食品安全是非常重要和有意义的。  相似文献   
3.
The results of mineralogical studies of technogenic tungsten raw material (stale tailings of Bom-Gorhon deposit) are represented. Its particle size distribution as well as tungsten and accompanying element distribution among the fractions were determined. The necessity of grinding the heaps down to 0.2-0.25 mm in size was established. It allows increasing the recovery rate of two or more times in comparison with the traditional pattern of tailing processing.  相似文献   
4.
Successful forensic DNA profiling from handled items is increasingly routine in casework. This “touch DNA” is thought to contain both cellular and acellular nucleic acid sources. However, there is little clarity on the origins or characteristics of this material. The cellular component consists of anucleate, terminally differentiated corneocytes (assumed to lack DNA), and the occasional nucleated cell. The acellular DNA source is fragmentary, presumably cell breakdown products. This study examines the relative contributions each component makes to the hand-secretions (endogenous) and hand-accumulations (exogenous) by recovering rinses from the inside and outside of worn gloves. Additionally, cellular and acellular DNA was measured at timepoints up to 2 h after hand washing, both with and without interim contact. Microscopic examination confirmed cell morphology and presence of nucleic acids. Following the novel application of a hair keratinocyte lysis method and plasma-DNA fragment purification to hand rinse samples, DNA profiles were generated from both fractions. Exogenous cell-free DNA is shown to be a significant source of touch DNA, which reaccumulates quickly, although its amplifiable nuclear alleles are limited. Endogenous DNA is mostly cellular in origin and provides more allelic information consistently over time.  相似文献   
5.
非晶态Fe-W合金镀层的表面改性   总被引:2,自引:0,他引:2  
将Fe-W非晶态镀层在铬酸盐钝化液中进行化学钝化与电化学钝化,使之形成含铬钝化膜。阳极极化曲线说明,钝化后镀层的孔蚀电位向正向移动了约1.68V;Fe-W非晶镀层在氯化钠溶液中浸泡近1h表面发生严重腐蚀,而经钝化处理的镀层浸泡1个月,表面无变化,仍具有金属光泽。  相似文献   
6.
制备温度对Pd/C加氢脱氯催化剂失活的影响   总被引:4,自引:0,他引:4  
制备温度对Pd/C加氢脱氯催化剂失活的影响;失活;积炭;Pd/C;加氢脱氯  相似文献   
7.
论中国海洋砂矿床类型   总被引:1,自引:0,他引:1  
本文总结了作者二十多年砂矿工作的经验,搜集了国内近三百处海洋砂矿床(点)五十余种矿床类型划分的资料,比照国外同类型矿床,结合我国矿床特征,提出了新的海洋砂矿分类原则,矿床工业类型、成因-形态类型、成矿时代类型和保存类型等的划分系统,以及今后的找矿方向。  相似文献   
8.
曾焕济  黄俐俐 《分析化学》2000,10(3):381-384
研制半自动定容试液,半自动定位恒速注入KBK4,整个氢化过程不串空气,可用压力全方位喷射冲洗反应室。该装置定容定位准确,操作简便快速,适用于大批量样品分析。通过对8个GSD标准参考物质的分析,分析结果与参考值基本一致,RSD<6%。  相似文献   
9.
在全面、系统收集和研究新疆富蕴县萨尔布拉克地区地质、地球物理、地球化学、矿产普查和科研资料的基础上,深入分析金矿成矿地质条件、控矿因素和找矿方法组合,对萨尔布拉克预测区95条断裂的地质、地球物理、地球化学特征进行了全面统计分析,确定了42条赋金断裂.其中早期断裂8条,占19%;晚期断裂34条,占81%.赋金断裂以晚期南北向为主,次为东西向和北西向.航磁异常向上延拓高度大者,即赋金断裂延深大者对金的成矿有利.  相似文献   
10.
The spectral emittance of deposits left by bituminous and sub-bituminous coals under oxidizing conditions have been measured in situ. Pulverized coal is injected into a down-fired entrained-flow reactor. Ash accumulates on a probe in the reactor effluent and radiation emitted by the ash layer is recorded using a Fourier transform infrared (FTIR) spectrometer. Values for the spectral emissive power emitted by the ash and the surface temperature of the ash are extracted from these data. These results are then used to calculate the spectral emittance of the deposit. The spectral emittances of ash deposits formed by burning Illinois #6 (bituminous) coal and Powder River Basin (sub-bituminous) coal were measured between 3000 and 500 wavenumbers. The spectral emittance of the deposit left by the bituminous coal has a constant value of approximately 0.46 between 3000 and 2400 wavenumbers. Between 2200 and 1200 wavenumbers, the spectral emittance of the deposit increases from approximately 0.47 to approximately 0.61. Between 1200 and 500 wavenumbers, the spectral emittance is relatively constant at 0.61. The spectral emittance of the deposit left by the sub-bituminous coal is also relatively constant between 3000 and 2400 wavenumbers at a value of 0.29. Between 2200 and 500 wavenumbers, the spectral emittance of deposits from the sub-bituminous coal increases from approximately 0.29 to 0.55. Differences between these spectral emittance measurements and those measured ex situ illustrate the importance of making in situ measurements. Band emittances were calculated using the measured spectral emittances, and band emittances of the deposits are reported as functions of temperature.  相似文献   
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