Polyoxometalate-Dicarboxylate Hybrid Dimers with {SiW10Cr2} Nodes: Syntheses, Structures, and Mass Spectrometric Characterization.

The current study describes a new family of hybrid dimers constructed from secondary building blocks based on a dichromium-substituted silicodecatungstate, {SiW10Cr2}, and flexible dicarboxylate ligands of varied lengths. All five polyoxometalate-organic hybrid compounds exhibit an entropically favored, cyclic dimer motif that contains just two {SiW10Cr2} clusters─the minimum to form a closed loop, linked by two aliphatic dicarboxylates, as revealed by single-crystal X-ray diffraction. Due to the kinetic inertness of such Cr3+-based hybrid dimers, ESI-MS has become a particularly useful technique for the characterization of these paramagnetic, NMR-unfriendly systems.

The Strain Rate Effects of Coral Sand at Different Relative Densities and Moisture Contents.

A 37-mm-diameter split Hopkinson pressure bar (SHPB) apparatus was used for impact loading tests to determine the effects of the relative density and moisture content on the dynamic properties of coral sand. The stress-strain curves in the uniaxial strain compression state were obtained for different relative densities and moisture contents under strain rates between 460 s-1 and 900 s-1. The results indicated that with an increase in the relative density, the strain rate becomes more insensitive to the stiffness of the coral sand. This was attributed to the variable breakage-energy efficiency at different compactness levels. Water affected the initial stiffening response of the coral sand, and the softening was correlated with the strain rate. Strength softening due to water lubrication was more significant at higher strain rates due to the higher frictional dissipation. The volumetric compressive response of the coral sand was investigated by determining the yielding characteristics. The form of the constitutive model has to be changed to the exponential form, and different stress-strain responses should be considered. We discuss the effects of the relative density and water content on the dynamic mechanical properties of coral sand and clarify the correlation with the strain rate.

Metal-Organic Cages with {SiW9 Ni4 } Polyoxotungstate Nodes.

A tritopic, Ni-substituted Keggin cluster, {SiW9 Ni4 }, assembles with rigid dicarboxylate linkers to give rise to a set of discrete, POM2n L3n -type structures (POM={SiW9 Ni4 }) with defined interior voids. The outcome of coordination-driven self-assemblies of these polyhedral cages-from fused dimers to trigonal prisms-was found to be sensitive to bend angles of the ditopic ligands, which vary from 122° to 180°. These polyoxotungstate-based metal-organic polyhedra, when coupled with [Ru(bpy)3 ]Cl2 as a photosensitizer and triethanolamine as the electron donor, serve as highly effective catalysts for CO2 reduction, with turnover numbers up to 328 and CO selectivity as high as 96.2 %. The inner cavities of such cage structures, if functionalized or of sufficient size to encapsulate targeted guest molecules, could present a new strategy towards functional materials for potential applications.

Direct one-step synthesis of CoFex@Co@C hybrids derived from a metal organic framework for a lightweight and high-performance microwave absorber.

It involves invariably strong expectations and a tough challenge to explore lightweight microwave absorption materials with high efficiency and agile tenability. Here, we successfully synthesized CoFex@Co nanoparticles embedded into a carbon matrix that was directly derived from the metal organic frameworks (MOFs) via a facile method. Benefiting from the unique multi-dimensional construction and synergistic effects of carbon material with magnetic nanoparticles in both the electromagnetic energy loss and impedance matching, CoFe0.26@Co@C composite exhibited excellent microwave absorption performance, which showed a minimum reflection loss of -62.5 dB at the thickness of 1.5 mm and a broad absorption bandwidth of 14.7 GHz exceeding -10 dB at the thickness range of 1.4 to 5 mm. This study not only provides a reference for future preparation of MOF-based lightweight microwave absorption materials, but also offers the possible application owing to its simple procedure and outstanding absorption properties.

Metal-organic framework derived cobalt phosphosulfide with ultrahigh microwave absorption properties.

Nanostructure composites of ferromagnetic materials embedded in nanoporous carbon (NC) derived from metal-organic frameworks (MOFs) have attracted enormous attention due to their potential application in many fields, such as microwave absorption, energy storage, and conversion. The rational design of nanocomposites holds a determinant factor for overcoming the challenges involving the microwave absorption performance. Herein, CoS2/NC, CoP/NC, and CoS2-xPx/NC with a rhombic dodecahedral structure have been successfully fabricated by using the template cobalt-based MOFs (ZIF-67). A morphology analysis indicates that ferromagnetic nanoparticles are embedded in NC matrix. It is obvious that the rhombic dodecahedron can be maintained after the phosphorization and sulfurization of Co/NC derived from the thermal decomposition of ZIF-67. The microwave absorption performance can obviously be improved by the phosphorization and sulfurization of Co/NC. CoS2-xPx/NC exhibits an excellent microwave absorption property and the minimum reflection loss (RL) of CoS2-xPx/NC can reach -68 dB at 14.6 GHz with a thickness of 1.5 mm. An RL value less than -10 dB can be achieved in the microwave frequency range of 12.7-17.3 GHz (4.6 GHz) with a thickness of 1.5 mm for CoS2-xPx/NC. This article offers a novel way to fabricate cobalt-based materials/carbon composites for an excellent microwave absorber.

The Alcohol Use Disorder and Associated Disabilities Interview Schedule-5 (AUDADIS-5): reliability of substance use and psychiatric disorder modules in a general population sample.

BACKGROUND: The purpose of this study was to assess the test-retest reliability of substance use disorder and psychiatric modules in the Alcohol Use Disorder and Associated Disabilities Interview Schedule, Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) Version (AUDADIS-5). METHODS: Kappa and intraclass correlation coefficients were calculated for DSM-5 substance use and psychiatric disorder diagnoses and dimensional criteria scales using a test-retest design among 1006 respondents drawn from the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III). RESULTS: Reliabilities of substance use disorder diagnoses and associated criteria scales were generally good to excellent, while reliabilities for mood, anxiety and trauma and stress-related disorders and associated scales were generally in the fair to good range. CONCLUSIONS: The observed reliability of the DSM-5 diagnoses and dimensional scales for the substance use and psychiatric disorders found in this study indicates that the AUDADIS-5 can be a useful tool in various research settings, particularly in studies of the general population, the target population for which it was designed.

Correlates of recovery from alcohol dependence: a prospective study over a 3-year follow-up interval.

BACKGROUND: Correlates of recovery from alcohol dependence have been identified through a variety of study designs characterized by different strengths and limitations. The goal of this study was to compare correlates of recovery based on a 3-year prospective design with those based on cross-sectional analyses of data from the same source. METHODS: Data from the 2001 to 2002 Wave 1 and 2004 to 2005 Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) were used to examine baseline characteristics associated with Wave 2 recovery from alcohol dependence, among those who classified with past-year DSM-IV alcohol dependence at Wave 1 (n = 1,172). RESULTS: Abstinent recovery was significantly associated with Black/Asian/Hispanic race/ethnicity, children <1 year of age in the household at baseline, attending religious services greater than or equal to weekly at follow-up, and having initiated help-seeking that comprised/included 12-step participation within <3 years prior to baseline. Nonabstinent recovery was positively associated with being never married at baseline, having job problems or being unemployed in the year preceding baseline, attending religious services less than weekly at follow-up, baseline smoking and volume of ethanol intake, and having terminated a first marriage within <3 years prior to baseline. Findings, including others of marginal significance (0.05 < p < 0.10), generally supported results from prior pseudo-prospective survival analyses with time-dependent covariates but differed in many ways from cross-sectional analyses of Wave 1 NESARC data. CONCLUSIONS: Various aspects of study design must be considered when interpreting correlates of recovery. Cross-sectional analyses of lifetime correlates of recovery are highly subject to misinterpretation, but pseudo-prospective survival analyses with time-dependent covariates may yield results as valid as those from prospective studies.