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A water-stable Zn-MOF was constructed based on H2PBA and 1, 10-phenanthroline under solvothermal conditions. The compound exhibited a 3D (2,3,8)-connected (43)2(46.66.815.12)(8) topology framework. The crystal structure and phase purity of the compound was verified by single crystal X-ray diffraction. Subsequently, some studies on the morphology, structure, and luminescent properties were carried out. The results showed that this compound could be used as a versatile chemosensor for Fe3+/Cu2+, trinitrophenol and colchicine via a luminescence quenching effect in an aqueous medium. [ABSTRACT FROM AUTHOR]

Searching for new low-dimensional organic–inorganic hybrid phosphors is of great significance due to their unique optical properties and wide applications in the optoelectronic field. In this work, we report a Mn4+ doped zero-dimensional organic–inorganic hybrid phosphor [N(CH3)4]2ZrF6, which was synthesized by a wet chemical method. The crystal structure, thermal stability, and optical properties were systemically investigated by means of XRD, SEM, TG-DTA, FTIR, DRS, emission spectra, excitation spectra, as well as decay curves. Narrow red emission with high color purity can be observed from [N(CH3)4]2ZrF6:Mn4+ phosphor, which maintains effective emission intensity even at room temperature, indicating its potential practical application in WLEDs. In the temperature range of 13–295 K, anti-Stokes and Stokes sidebands of Mn4+ ions exhibit different temperature responses. By applying the emission intensity ratio of anti-Stokes vs. Stokes sidebands as temperature readout, an optical thermometer with a maximum absolute sensitivity of 2.13% K−1 and relative sensitivity of 2.47% K−1 can be obtained. Meanwhile, the lifetime Mn4+ ions can also be used for temperature sensing with a maximum relative sensitivity of 0.41% K−1, demonstrating its potential application in optical thermometry. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel algorithm for mining complete frequent itemsets. This algorithm is referred to as the TM (Transaction Mapping) algorithm from hereon. In this algorithm, transaction iris of each itemset are mapped and compressed to continuous transaction intervals in a different space and the counting of itemsets is performed by intersecting these interval lists in a depth-first order along the lexicographic tree. When the compression coefficient becomes smaller than the average number of comparisons for intervals intersection at a certain level, the algorithm switches to transaction id intersection. We have evaluated the algorithm against two popular frequent itemset mining algorithms, FP-growth and dEclat, using a variety of data sets with short and long frequent patterns. Experimental data show that the TM algorithm outperforms these two algorithms. Index Terms--Algorithms, association rule mining, data mining, frequent itemsets.

Ce3+/Tb3+ co‐doped NaMgBO3 phosphors were successfully synthesized by solid‐state method. Under 381 nm excitation, the cyan emission owing to the 5d → 4f of Ce3+ ions and green emissions arising from the 5D4 → 7FJ (J = 6, 5, 4, and 3) transitions of Tb3+ ions were seen in all the phosphors. Through theoretical analysis, one knows that the energy transfer from Ce3+ to Tb3+ ions with high efficiency of 83.74% was contributed by dipole–dipole transition. Furthermore, the internal quantum efficiency of NaMgBO3:0.01Ce3+,0.03Tb3+ phosphor was 54.28%. Compared with that of at 303 K, the emission intensity of the developed products at 423 K still kept 73%, revealing the splendid thermal stability of the studied phosphors. Through utilizing the resultant phosphors as cyan‐green components, the fabricated white‐LED device exhibited an excellent correlated color temperature of 2785 K, high color‐rendering index of 85.73, suitable luminance efficiency of 25.00 lm/W, and appropriate color coordinate of (0.4279, 0.3617). Aside from the superior photoluminescence, the synthesized phosphors also exhibited excellent cathode‐luminescence properties which were sensitive to the current and accelerating voltage. Furthermore, the NaMgBO3:0.01Ce3+,0.03Tb3+ phosphors with multi‐mode emissions were promising candidates for optical anti‐counterfeiting. All the results indicated that the Ce3+/Tb3+ co‐doped NaMgBO3 phosphors were potential multi‐platforms toward white‐LED, field emission displays, and optical anti‐counterfeiting applications. [ABSTRACT FROM AUTHOR]