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《中国有色金属学会会刊》2021,31(11):3530-3548
In-situ LA-ICP-MS and S isotopes of pyrite from the Baoshan Cu polymetallic deposit were conducted to investigate the ore-forming process and the enrichment mechanism of elements. Three generations of pyrite (Py I, Py II, and Py III) in the skarn-type ores and pyrite in the carbonate-hosted sulfide ores from central, western, and northern (C_Py, W_Py, and N_Py) mining districts are selected for comparison. Compared with Py I and Py III, the contents of most elements in Py II are apparently higher. The As and Se contents are high within a wide range and are decoupled in the growth band of the C_Py. The highest As, Se, and Pb contents were found in W_Py and N_Py. These results indicate the drastic changes in the temperature and fluid mixing during the mineralization. The occurrence of fluctuation and change in temperature and f(O2) was triggered by intermittent pulses of magmatic-hydrothermal fluids, mixing with meteoric water, and water−rock interactions. The sulfur isotopes of all species of pyrite indicated the magmatic source. The change in the f(O2) conditions caused slight differences in the sulfur isotope compositions. Consequently, a metallogenic model was proposed to explain the ore-forming processes. 相似文献
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现有的数字语音取证研究主要集中于对单一的某种操作进行检测,无法对不相关的操作进行判断。针对该问题,提出了一种能够同时检测经过变调、低通滤波、高通滤波和加噪这四种操作的数字语音取证方法。首先,计算语音的归一化梅尔频率倒谱系数(MFCC)统计矩特征;然后通过多个二分类器对特征进行训练,并组合投票得到多分类器;最后使用该多分类器对待测语音进行分类。在TIMIT以及UME语音库上的实验结果表明,归一化MFCC统计矩特征在库内实验中均达到了97%以上的检测率,且在对MP3压缩鲁棒性测试的实验中,检测率仍能保持在96%以上。 相似文献
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236Pu的含量控制是钚热源的一项重要参数,通过α能谱准确测量镎靶溶解液中痕量236Pu,建立镎靶辐照靶件溶解液中钚的分离方法。根据杂质组成特点采用TBP-TEVA萃取色层双柱分离,用氨基磺酸亚铁以及亚硝酸钠对钚进行调价,对靶件溶解液中的Al、Fe、U、Th和Np等进行分离,去污系数均大于104,钚的回收率为90.7%。研究大量238Pu对α能谱测定236Pu的干扰,结果表明,大量238Pu会造成仪器本底升高,238Pu能谱峰分辨率降低;在7 500 Bq 238Pu干扰下,测量4.3 h 时,236Pu的最小可检测活度为1.20×10-2 Bq(当量质量为6.11×10-16 g)。计算结果表明,镎靶溶解液样品中钚的同位素比值n(236Pu)/n(238Pu) ≥4.63×10-8时,取合适的样品量使得电沉积源中238Pu 活度在 450~7 500 Bq范围内,均可测量其中的痕量236Pu,同时可准确测定同位素比值n(236Pu)/n(238Pu)。 相似文献
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An on-site laboratory with direct access to cleaned and conditioned steel mill gases was recently put into operation. The long-term performance and stability of Clariant's MegaMax®800 methanol synthesis catalyst utilizing steel mill gases is currently being investigated. First test results revealed that in order to investigate deactivation mechanisms arising from particular properties of the cleaned steel mill gases, the overlaying effect of thermal deactivation of the catalyst has to be minimized. 相似文献
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表面增强拉曼散射(SERS)是一种新型痕量表征技术,其灵敏度高、样品用量少、特征谱易辨识,尤其适用于铀酰离子等危化品的探测。在过去十几年里, 纳米材料和纳米技术在新兴技术和SERS的应用方面获得了长足发展,将先进的纳米制造技术引入了SERS领域。本文总结了利用光刻、原子层沉积等技术,开发了一系列高质量的三维阵列纳米材料作为SERS基底,并应用于痕量铀酰离子的检测。其中,以Al2O3、HfO2等惰性氧化物包裹修饰的银纳米棒三维阵列作为基底,灵敏度高,稳定性好,根据不同特征的拉曼振动频谱,可识别多个不同种态的铀酰离子,检出限低至nmol/L,具有潜在的实际应用价值。 相似文献
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Design and fabrication of thermoelectric waste heat reutilization system—possible industrial application 下载免费PDF全文
Souvik Biswas Ayan Roynaskar Chetan Kumar Hirwani Subrata Kumar Panda 《国际能源研究杂志》2018,42(12):3977-3986
The current article discussed the detail design and development of an experimental test rig to derive usable energy by utilizing the waste heat energy through a heat exchanger made of Bi2Te3 material. The accuracy including the efficiency of the fabricated device is demonstrated further by verifying the associated parameter through a simulation model (commercial finite element package, ANSYS 15.0). To imitate the waste hot air from the industry is achieved via a heat gun and fed to the test rig for the generation of thermoelectric power. The simulation model accuracy has been demonstrated by juxtaposing the associated experimental data and computational readings. Subsequently, the feasibility and optimum range of design parameters are established by comparing the experimental and the simulation data (triggered temperature difference, voltage output, and heat flux) generated at the interface of the thermoelectric power generators. In addition, the coefficient of determination (R2) value has been evaluated statistically and verified with the current experimental results for the demonstration of the relevancy. The statistical study shows the existence of the correlation between the current experimental and the simulation model. Also, the experimental result indicates the possible implementation of the newly developed system for the recovery from the waste heat either the automobile exhaust or any other kind of dissipated heat from the industries. 相似文献
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The oxygen vacancy levels as a factor on different gadolinia-doped ceria interlayer (GDCi) films deposited on yttria stabilized zirconia (YSZ) electrolyte substrates by an atmospheric pressure plasma jet (APPJ) via precursor solution of nitrate salts are investigated. Focusing on the effect of carrier gases, scanning electron microscopy (SEM), Raman, and X-ray diffraction (XRD) are implemented for the materials characterization of the as-deposited GDCi films and sintered-GDCi films at various temperatures. The higher level of oxygen vacancies in GDCi films adhered on 8YSZ electrolyte are evidently analyzed using Ar as the carrier gas during the deposition, of which the interdiffusion resulted in the formation of (GDC + YSZ) solid solution for sintering over 1300?°C degraded the total conductivity. The deposition of GDCi films on 8YSZ by APPJ method using O2 carrier gas significantly improved the total conductivities of the whole electrolyte layers. Moreover, this study provides the useful insight into the oxygen vacancy levels on GDC films as interlayer (GDCi) to improve the values of open circuit voltage in LSM/GDCi/YSZ/Pt full-cell, as well as offering the efficiency of APPJ as one step deposition process. 相似文献