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A method for detecting large-size diamonds with low content in a complex mixture was described. Phase identification via conventional X-ray diffraction method is unsuitable because of the large-size and low-content characteristics of the diamonds. Thus, we proposed a convenient approach (i.e., rocking scan) for assessing the presence of low-content diamonds in a complex mixture. A thorough rocking scan of the (111), (220), and (311) planes revealed the presence of low-content diamonds prepared by reducing dense carbon dioxide with alkali metals. This procedure can be successfully applied to several standard mixture samples prepared by mixing α-SiO 2 , α-Al 2 O 3 , graphite, and pure diamond powders, which are commercially available. We estimated that the detection limit was at or below the 0.1 wt% level by using the proposed method under the current condition. This method is straightforward, routinized, and may be specifically developed to satisfy the requirements of public and private institutions for a rapid identification of other mixture phases, of which the large-size and low-content characteristics do not allow an instant phase identification by conventional X-ray diffraction methods. [ABSTRACT FROM AUTHOR]

In this work, we have developed a simple and facile method to synchronously synthesize hollow FeSe2/C nanospheres using the Kirkendall effect. When evaluated as an anode for SIBs, the hollow FeSe2/C nanospheres exhibit a high discharge capacity retention of 474.1 mA h g−1 at 0.05 A g−1 (based on the calculation of FeSe2), which is very close to the theoretical capacity of FeSe2 (∼500 mA h g−1). Meanwhile, hollow FeSe2/C also has a superior rate capability of 364.5 and 316.5 mA h g−1 even at 2.0 and 5.0 A g−1, respectively. The high performance of the hollow FeSe2/C nanospheres can be ascribed to the unique carbon coated hollow nanostructure. [ABSTRACT FROM AUTHOR]

N-doped Si nanoparticles were prepared synchronously by nitridation of Mg2Si. The existence of nitrogen doping can be demonstrated by the XPS spectrum and EELS energy-filtered images. When the N-doped Si nanoparticles were used as an anode for Li-ion batteries, a high reversible capacity of 2595 mA h g−1 at 0.36 A g−1 after 40 cycles, and 805 mA h g−1 at 3.6 A g−1 after 800 cycles could be obtained. [ABSTRACT FROM AUTHOR]