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Copper in copper ores is commonly determined by a manual visual titration method. The method has large errors, poor precision and poor reliability due to the need to gauge the end of the chemical reaction by a chemical indicator. Based on these disadvantages, a high precision determination method for high Cu content in Cu ores has been developed. In this new method, the terminal point is determined by intelligent potentiometric titrator automatically and the amount of sodium thiosulfate standard solution is accurate to 0.001 mL by a high-resolution dosing device. Moreover, the amount of potassium iodide is increased to eliminate the absorption of iodine with copper iodide which was produced during titration, as the copper iodide can be dissolved by high concentrations of iodide. National standard materials such as copper concentrate, chalcopyrite and lead brass with copper content ranging from 24.2% to 59.09% are determined using this method. The relative standard deviation is lower than 0.3%(n=10). The extreme differences are 0.13%, 0.21% and 0.29%, better than manual visual titration. The proposed method improves the automation for accurate determination of ores with Cu content greater than 0.5%, especially for those with Cu content more than 10%.

It is difficult to dissociate Cl by plasma because of the high ionization energy. Since the optical path of Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) cannot produce a low enough vacuum, the light wave of Cl is absorbed intensively causing difficulty in identifying the characteristic spectrum and subsequently in obtaining an accurate measurement of Cl in geology samples. In this article, a method is described here for completely extracting Cl in marine sediment samples by 10% ammonia with 30 minutes ultrasound bath. The Cl was measured by ICP-AES with an analysis spectrum of 725.670 nm. The detection limit of this method, which was based on ten standard deviations of the blank (10σ, dilution factor=100), was 50 μg/g for Cl. The accuracy and precision of the method were verified by analyzing different geological certified reference materials GBW 07313, GBW 07315 and GBW 07316. The relative standard deviations (RSD, n=7) of the results of independent determination GBW 07316 were 4.3%-8.6%, and relative error (n=7) were 2.9%-7.5%. Compared with traditional methods, this method is simple, fast, easy to perform, and its precision and accuracy are suitable for marine geochemistry.

Number, CI （corporation image） and creativity of SP （services provider）, set up a theory model on WVAS（wireless value-added services） market and SP regulation, to research regulation’s impact on SP market were analyed. The model shows that the impact can be classified to four areas: free area, loose area, rational area and restrict area. Through analyzing financial impact of regulation via SP, finds the importance of reinforcing regulation. The last part gives some suggestions by model analysis and experience analysis.

Carbon materials derived from metal-organic frameworks have attracted increasing attention as anodes for energy storage. In this study, Fe, Ni-doped ZIF-8 is carbonized at high temperature to obtain bimetallic Fe and Ni modified tension -relaxed carbon (FeNi@trC). Fe and Ni have opposite structural modification effects when the metal ions are doped into the ZIF-8 dodecahedron. The obtained carbon material maintains the regular dodecahedron morphology, which means the relaxation of tension and strong thermal stability during annealing. Moreover, the presence of nickel enhances the carbonization degree and electrochemical stability of FeNi@trC, while the calcination of the tensive ZIF-8 precursor offers more defect sites. The discharge capacities of FeNi@trC materials are stable at 182.9 mAh·g−1 and 567.9 mAh·g−1 for sodium-ion batterie (SIB) and lithium-ion batterie (LIB) at 0.05 A·g−1. Compared with the current density of 0.05 A·g−1, the discharge capacity of SIB and LIB attenuates by 29.4% and 55.9% at 1 A·g−1, respectively, and the FeNi@trC shows good performance stability in the following cycles. [ABSTRACT FROM AUTHOR]

Nanocatalysts are likely to contain undetected single-atom components, which may have been ignored but have significant effect in catalytic reactions. Herein, we report a catalyst composed of Mo single atoms (SAs) and MoO2 nanoparticles (NPs) (MoSAs-MoO2@NC), which is an exact model to understand how the SAs contribute to the nanocatalyst. Both experimental results and the density functional theory calculations reveal that Mo SAs on nitrogen-doped carbon provides the reaction zone for nitro reduction, while MoO2 is the active site for decomposing hydrazine hydrate to produce H⋆. Thanks to the synergy between Mo SAs and MoO2 NPs, this catalyst exhibits noble metal-like catalytic activity (100% conversion at 4 min) for the dechlorination-proof transfer hydrogenation. Additionally, the hydrogen migration on the catalyst is verified by the electrochemical tests in the absence of a hydrogen source. This work provides a model for further study on the coexistence of single atoms in nanoparticle catalysts. [ABSTRACT FROM AUTHOR]

Small‐molecule induction can lead to the oriented migration of metal elements, which affords functional materials with synergistic components. In this study, phosphating nickel foam (NF)‐supported octahedral WO3 with phosphine affords P‐WO3/NF electrocatalyst. Ni is found to form Ni−P bonds that migrate from NF to WO3 under the induction of P, resulting in the complex oxides W1.3Ni0.24O4 and Ni2P2O7 in the particle interior and nickel phosphide on the octahedral grain surface. The catalytic activity of P‐WO3/NF in the urea oxidation reaction (UOR) is improved by synergistic action of the components in the synthesized hybrid particles. A current density of 10 mA cm−2 can be reached at a potential of 1.305 V, the double layer capacitance of the catalyst is significantly increased, and the electron transfer impedance in catalytic UOR is reduced. This work demonstrates that small‐molecule induction is suitable for constructing co‐catalysts with complex components in a simple protocol, which provides a new route for the design of highly efficient urea oxidation electrocatalysts. [ABSTRACT FROM AUTHOR]