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Abstract A series of Na 2 TiF 6 : x Mn4+ samples were prepared by the cation exchange method. Visible QC behavior and the strongest ZPL peaks were observed for these samples. The characteristic of the visible QC behavior is that PL intensity at 620 nm is 1.61 times as high as PLE intensity at 476 nm. The mechanisms of these phenomena were discussed, and the color purity, crystal-field and nephelauxetic effect, the critical distance and the multipolar interaction for the samples were determined. The result shows that the Mn4+ ions are located at a strong crystal field and the concentration quenching of Mn4+ is from the quadrupole-quadrupole interaction. The slightly increase of nephelauxetic ratio causes the slightly blue shift of emission. The color-purity and chromaticity coordinates of the optimal sample suggests that the strongest ZPL makes its red emission with high color-purity. Thus, Na 2 TiF 6 :0.08Mn4+ is a potential red-emitting phosphor for blue light-based WLEDs. [ABSTRACT FROM AUTHOR]

Soil conservation ecosystem services (SCESs) are related to food production, safety of residents, water quality, and public health. However, the traditional assessment framework only focuses on a single dimension of SCESs, and the efficiency and development trends are often overlooked. A multidimensional assessment framework was established to assess SCESs in terms of the total output, efficiency, development trend temporally and spatially. Additionally, the traditional perspective of influencing mechanism analysis was expanded to include spatial heterogeneity. The influencing strength and distance were quantitatively revealed at pixel resolution. The results indicate that (1) the SCESs in Minnesota were generally improved from 1998 to 2018. (2) 70% and 78% of the counties experienced low-output and low-efficiency problems, respectively. (3) The Twin Cities constituted the degradation cores of SCESs in Minnesota. (4) The cropland and forestland proportions and rainfall were the top three influencing factors, causing SCES changes of 0.9959%, 0.4937%, and 0.1536%, respectively, for every 1% change in these factors. (5) According to the influence scopes, the soil organic carbon (SOC) content, normalized difference vegetation index (NDVI), and soil silt content were classified as long-distance factors, the soil sand content, slope and soil clay content were categorized as moderate-distance factors, and the remaining variables were identified as short-distance factors. (6) The influencing factors imposed both positive and negative influences on the SCESs, and attenuation or alteration of the adverse influences on SCESs through specific human interventions is a very promising approach. • A multidimensional assessment framework was proposed. • The SCESs in Minnesota has been severe with an upward development. • Degradations were classified into five types at county level and concentrated at "Twin Cities". • The proportions of cropland, forestland, and rainfall were the strongest influencing strength factors. • The influencing factors are classified as long-distance, moderate-distance, and short-distance factors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reversible MnO 2 /Mn2+ transformation is realized in mild aqueous electrolytes. • The Zn-Mn hybrid battery exhibit high discharge capacity and long cycle life. • The disproportionation of Mn3+ triggers the Mn2+ dissolution. • H+/Zn2+ insertion and the disproportionation occur sequentially upon discharging. The disproportionation of the Jahn-Teller (J-T) active manganese oxides (Mn3+) often leads to uncontrollable Mn2+ dissolution, which has been identified as one of the major causes of the performance degradation in conventional Zn-MnO 2 batteries. Herein, we use the "unwanted" disproportionation of the Mn3+ cations to realize effective MnO 2 /Mn2+ transformation, achieving high specific capacity (550 mAh g−1) and good cycling stability (5000 cycles without capacity decay) in a Zn-MnO 2 hybrid battery with mild aqueous electrolytes. Mechanism study shows that MnO 2 is deposited on the cathode during charging, H+/Zn2+ insertion and disproportionation occur sequentially during discharging, leading to Mn2+ dissolution. The generated high-valence manganese oxides via disproportionation further experience reduction-disproportionation-dissolution, which proceeds repeatedly in the expanded discharge potential to 0 V vs. Zn2+/Zn, resulting in the complete dissolution of the cathodic materials. Our results provide the fundamental understanding on the controversial mechanisms of Zn-MnO 2 batteries with mild aqueous electrolytes and highlight the effect of disproportionation in pushing the electrochemical performance of the promising Zn-MnO 2 hybrid batteries. [ABSTRACT FROM AUTHOR]