[en] Highlights: • X-ray scattering was used for monitoring oxidation situation of SiC ceramics. • A calibration curve was obtained. • The confocal X-ray scattering technology was based on polycapillary X-ray optics. • The variations of contents of components of SiC ceramics were obtained. - Abstract: In the present work, we presented an alternative method for monitoring of the oxidation situation of silicon carbide (SiC) ceramics at various high temperatures in air by measuring the Compton-to-Rayleigh intensity ratios (I_C_o/I_R_a) and effective atomic numbers (Z_e_f_f) of SiC ceramics with the confocal energy dispersive X-ray fluorescence (EDXRF) spectrometer. A calibration curve of the relationship between I_C_o/I_R_a and Z_e_f_f was established by using a set of 8 SiC calibration samples. The sensitivity of this approach is so high that it can be easily distinguished samples of Z_e_f_f differing from each other by only 0.01. The linear relationship between the variation of Z_e_f_f and the variations of contents of C, Si and O of SiC ceramics were found, and the corresponding calculation model of the relationship between the ΔZ and the ΔC_C, ΔC_S_i, and ΔC_O were established. The variation of contents of components of the tested SiC ceramics after oxidation at high temperature was quantitatively calculated based on the model. It was shown that the results of contents of carbon, silicon and oxygen obtained by this method were in good agreement with the results obtained by XPS, giving values of relative deviation less than 1%. It was concluded that the practicality of this proposed method for monitoring of the oxidation situation of SiC ceramics at high temperatures was acceptable.

[en] Dip-pen nanolithography (DPN) has been developed to pattern monolayer film of various molecules on suitable substrate through the controlled movement of ink-coated atomic force microscopy (AFM) tip, which makes DPN a potentially powerful tool for making the functional nanoscale devices. In this paper, the direct patterning of rhodamine 6G on mica by dip-pen nanolithography was demonstrated. R6G features patterned on the mica was successfully achieved with different tip movement which can be programmed by Nanoscript language. From the AFM image of R6G patterns, we know that R6G molecule is flatly binding to the mica surface through electrostatic interaction, thus stable R6G nanostructures could be formed on mica. The influence of translation speed and contact time on DPN was discussed. The method can be extended to direct patterning of many other organic molecules, and should open many opportunities for miniaturized optical device and site-specific biological staining

[en] Nanocrystalline SnO₂ powders have been synthesized by two-step solid state reaction technique. Firstly, the brown SnO particles were obtained by grinding mixed SnCl₂·2H₂O and KOH powders at room temperature. Then, the powders were calcined in air (thermal oxidation) to form the SnO₂ nanoparticles. The phase compositions and microstructures of the product were examined by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM), respectively. Furthermore, we have measured the gas-sensing property of the products and found its distinct selectivity towards ethanol at the presence of gasoline and acetylene, which is different from the property of pure SnO₂ nanoparticles. The mechanism of such a specificity was discussed briefly

[en] By sampling in the different geochemical zone of Middle Jurassic in the drillhole and in the fundamental rock of north mountain in the northern margin of Qaidam Basin. detection and studying on the REE, discuss the REE characteristic, writers considered that the type of initial rock in the Middle Jurassic is magmatic rock, formed at active continental margin. According to (La/Yb)-REE diagram analysis, indicates that the sandstone of the north mountain. With different geochemical REE on the content variate indicates that is light REE concentration in oxidation and redox zone, heavy REE are moved to reducing zone by groundwater, uranium and light REE manifest the similar geochemistic characteristics, open out the water-rock reciprocity between REE and uranium metallogenesis. (authors)

[en] Auto-oscillation and chaotic behavior were investigated experimentally in a plasma system produced by discharge through mixing He-Ne gases. The glow power spectra and the differential phase-space portraits show period-doubling and Ruelle-Takens routes to chaos. Periodic windows embedded in chaos and multiple subharmonic bifurcations occurring in the windows were observed

[en] Microorganism play a direct and undirect role in the process of deposit formation. Some cells can obtain the existing energy during the process from U⁶⁺ to U⁴⁺ and play a very important role in the process of uranium mineralization. This paper analysed the distribution character of cells in different geo chemistry zone of Shihongtan uranium deposit and discussed the relationship between the metabolism of cell life and the migration and enrichment of uranium. The paper established the mineralizing model in Shihongtan uranium deposit. (authors)

[en] By the statistics and comprehensive analysis of geologic documentation and well logging data of drill cores and outcrops in Baxiankou area of Turpan, the target uranium exploration layers of Low-middle Jurassic was divided into three depositional system: braided river-delta system; shallow lacustrine and swampy system and meandering river system. Characteristic of these systems and their relation to uranium mineralization was discussed in the paper. It was pointed out that the braided river-delta depositional system is the best environment to sandstone type uranium mineralization and the main ore-controlling micro-facies are distributary channel and the front delta. (authors)

[en] The Shihongtan uranium deposit is the interlayer oxidation zone sandstone type uranium deposit, and this uranium deposit generated in Aiding Lake slope in southwest margin of Turpan-Hami basin. The paper analyzes the relationship between the deposit and the local structure, and thinks that based on controlling hydrodynamic conditions of partial area, not only the development and the distribution of interlayer oxidation zone but also the formation and spatial location of uranium mineralization is controlled by the local structure. It indicates that monoclinal structure is the most fundamental conditions to form this type uranium deposit, the fractures and anticlines in the monoclinal structure can cause the formation of interlayer oxidation zone sandstone type uranium deposits by changing the characteristics of partial groundwater. The study is conducive to exploring and improving ore-prospecting results by strengthening the analysis and research of local structure. (authors)

[en] By the testing result of samples, analyse othernesses among the soluble organic matter, the matrix of acidolysis hydrocarbon and the type of organic matrix of overlying coal beds, which composed the reducing geochemical barrier of host rock to mineralization in Shihongtan uranium deposit, think that the organic matrix is humosapropelic type (Ⅱ) in overlying coal beds, while the organic matter is humified type (Ⅲ 1) in the ore and pellet rock, prove that soluble organic matter and acidolysis hydrocarbon that don't come from the overlying coal beds are the products of organic matter bio chemical process. As the positive confining bed, overlying coal beds can't become the qist for choosing mineral bed of interest. Finally, writes put forward that we should enhance the research and explore in 2nd lithohorizon besides 1st and 3rd lithohorizon. (authors)

[en] This article introduces the basic principle and method to calculate the eroded stratum depth with acoustic logging data. The eroded depth of Jurassic in the north of Shihongtan area was calculated and character of erosion thickness was summarized for Jurassic in the area which can be used as reference to analyse the evolutionary process and history of the basin. (authors)