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In 1980, Bressoud conjectured a combinatorial identity A j = B j for j = 0 or 1. In this paper, we introduce a new partition function B ~ 0 which can be viewed as an overpartition analogue of the partition function B 0 . An overpartition is a partition such that the last occurrence of a part can be overlined. We build a bijection to get a relationship between B ~ 0 and B 1 , based on which an overpartition analogue of Bressoud's conjecture for j = 0 is obtained. [ABSTRACT FROM AUTHOR]

In this study, high-pressure high-temperature nanodiamonds (HPHT NDs) and detonation nanodiamonds (DNDs) were both treated by air oxidation to investigate the influence of heat treatment on the aggregate size distribution, surface state and fluorescence characteristics of nanodiamonds (NDs). The results show that the oxidation in air can reduce the aggregate size distribution and increase the surface oxygen group concentration of both NDs. It can also improve the crystalline quality as well, by removing the non-diamond sp2 carbon phase on the surface. However, the HPHT NDs and DNDs show very different fluorescence intensity variation as a function of heat treatment. It is observed that the average fluorescence intensity of HPHT NDs increases by 24.5% due to the removal of non-diamond sp2 carbon, which is believed to cause the emission quenching of HPHT NDs. Therefore, the internal Nitrogen-vacancy (NV) defects in the sp3 structure are speculated as the dominated source of the luminescence for HPHT NDs. On the contrary, the average fluorescence intensity of DNDs decreases with an increase in heat treatment time. It can be inferred that the fluorescence origin of DNDs mainly comes from fluorophore related to the surface non-diamond sp2 carbon, rather than the internal NV defects. [ABSTRACT FROM AUTHOR]

Two coordination polymers, [Zn(Btec)0.5(H2L)]n (I) and [Cd0.5(Tp)0.5(H2L')(H2O)]n ∙ nH2O (II) (H2L = 3-(1H-pyrazol-4-yl)-5-(pyridin-2-yl)-1,2,4-triazole; H4Btec = 1,2,4,5-benzenetetracarboxylic acid; H2L' = 3-(1H-pyrazol-4-yl)-5-(pyridin-3-yl)-1,2,4-triazole; H2Tp = terephthalic acid), have been synthesized under hydrothermal conditions. The title compounds were structurally characterized by elemental analysis, single crystal X-ray diffraction analysis, infrared spectra. Compounds I and II crystallize in the orthorhombic and triclinic, space group Pbca and P¯1, respectively. Compound I displays a two-dimensional plane structure, those are connected by N···H···O hydrogen bonds to generate 3D frameworks. Compound II is constructed a 1D chain structure by Tp2− ligands, which are connected into 2D structure by the hydrogen bonds. In addition, the fluorescent property of I has been studied in the solid state at room temperature. The thermal analysis of I has also been investigated. [ABSTRACT FROM AUTHOR]

Diamond-based semiconductor with high electrical conductivity is a key point in diamond device development. In this paper, a thin single crystal diamond layer of high quality was epitaxially grown on a commercial tool-grade diamond seed by incorporating active O atoms from the typical growth environment. Subsequently, the H-termination density was enhanced on the diamond surface by exposure to the pure hydrogen plasma, and the surface conductivity of H-terminated diamond was analyzed in detail. The thin epitaxial layers on the high-pressure high-temperature diamond seeds show lower resistance than the ones on the chemical vapor deposition diamond seeds, which could be comparable with the lowest values reported. After the thin diamond layers were grown with and without addition of O2, the carrier mobility in the conductive channel increased to almost 80 cm2 V−1 s−1 under O2 contained condition, much higher than those without O2 incorporation. The ionization scattering is dominant to the carrier mobility compared with the surface scattering. The higher carrier mobility is attributed to the lower impurity density in the epitaxial layer, which is because the active O atoms could purify the epitaxial layer by removing or reducing Si- and N-related impurities. [ABSTRACT FROM AUTHOR]

Ar + H2 plasma interacting with liquid lithium was carried out on a one-cathode linear plasma device (SCU-PSI). The lithium sample was covered with capillary porous structure (CPS). It is found that the electron temperature of applied plasma ranged from ~0-1 eV and electron density ranged from 0.1 × 1020 to 1 × 1020 m−3. The experimental results indicate that a reduction in the electron temperature and the lithium evaporation is found as the percentage of H2 increases When the ratio of argon and hydrogen keeps constant, the electron temperature and lithium evaporation increase with applied input power, respectively. The retention of hydrogen atoms in lithium surface results in reducing the lithium evaporation. The XRD analysis result shows that during plasma radiation no LiH is formed. [ABSTRACT FROM AUTHOR]

A new Co(II) compound, namely [Co(CH3O-H2Ip)(Bip)]n (I) (CH3O-H2Ip = 5-methoxylisophthalic acid and Bip = 3,5-bis(imidazole-1-yl)pyridine), has been synthesized through combination of CH3OH2Ip, Bip and Co(II) acetate under hydrothermal condition and structurally characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction (CIF file CCDC no. 977220). It crystallizes in triclinic, space group with a = 9.764(6), b = 10.106(6), c = 11.673(7) Å, α = 104.12970°, β = 100.601(7)°, γ = 105.324(7)°, V = 1038.6(11) Å3, C20H16CoN5O5, Mr = 465.31, Z = 2, ρcalcd = 1.488 g/cm3, μ(MoKα) = 0.869 mm-1, F(000) = 476, the final R = 0.0652 and wR = 0.1530. The X-ray analysis demonstrates that compound I exhibits a 2D + 2D polyrotaxane (4, 4) net network. Moreover, the thermal analysis of compound I has also been investigated. [ABSTRACT FROM AUTHOR]