Enhanced Hydrogen Storage by Palladium Nanoparticles Fabricated in a Redox‐Active Metal–Organic Framework

Quick on the uptake : Palladium nanoparticles were fabricated simply by immersing {[Zn₃(ntb)₂(EtOH)₂]?4 EtOH}_n ( 1 ) in an MeCN solution of Pd(NO₃)₂ at room temperature, without any extra reducing agent. 3 wt % PdNPs@[ 1 ]^0.54+(NO₃^?)_0.54 significantly increase H₂ uptake capacities, both at 77 K and 1 bar and at 298 K and high pressures (see picture, red curve) compared to [Zn₃(ntb)₂]_n (black). ntb=4,4′,4′′‐nitrilotrisbenzoate.

     

All‐in‐One Target‐Cell‐Specific Magnetic Nanoparticles for Simultaneous Molecular Imaging and siRNA Delivery

Cancer‐cell‐targeted gene silencing was observed with a magnetic‐nanoparticle platform (MEIO, magnetism‐engineered iron oxide) on which a fluorescent dye, siRNA, and a RGD‐peptide targeting moiety were attached (see picture). The different functionalities enable the macroscopic (magnetic resonance) and microscopic (fluorescence) imaging of target cells. This system may be suitable for concurrent diagnostic and therapeutic applications.

     

A relationship between subpermanents and the arithmetic-geometric mean inequality

Using the arithmetic-geometric mean inequality, we give bounds for k-subpermanents of nonnegative n×n matrices F. In the case k=n, we exhibit an n²-set S whose arithmetic and geometric means constitute upper and lower bounds for per(F)/n!. We offer sharpened versions of these bounds when F has zero-valued entries.     

Analytical solutions of dynamic mode I crack under the conditions of displacement boundary

By the approaches of the theory of complex variable functions, the problems of dynamic mode I crack under the condition of displacement boundary are investigated. For this kind of dynamic crack extension problems with arbitrary index of self-similarity, the universal representations of analytical solutions are facilely deduced by the methods of self-similar functions. Analytical solutions of the stresses, displacements and stress intensity factors are readily acquired using the methods of self-similar functions. The problems studied can be very easily translated into Riemann–Hilbert problems and their closed solutions are gained rather straightforward in terms of this technique. According to corresponding material properties, the mutative rule of stress intensity factor was illustrated very well. Using those solutions and superposition theorem, the solutions of arbitrarily complex problems can be attained.     

Coordination-chemistry control of proton conductivity in the iconic metal-organic framework material HKUST-1

HKUST-1, a metal-organic framework (MOF) material containing Cu(II)-paddlewheel-type nodes and 1,3,5-benzenetricarboxylate struts, features accessible Cu(II) sites to which solvent or other desired molecules can be intentionally coordinated. As part of a broader investigation of ionic conductivity in MOFs, we unexpectedly observed substantial proton conductivity with the "as synthesized" version of this material following sorption of methanol. Although HKUST-1 is neutral, coordinated water molecules are rendered sufficiently acidic by Cu(II) to contribute protons to pore-filling methanol molecules and thereby enhance the alternating-current conductivity. At ambient temperature, the chemical identities of the node-coordinated and pore-filling molecules can be independently varied, thus enabling the proton conductivity to be reversibly modulated. The proton conductivity of HKUST-1 was observed to increase by ~75-fold, for example, when node-coordinated acetonitrile molecules were replaced by water molecules. In contrast, the conductivity became almost immeasurably small when methanol was replaced by hexane as the pore-filling solvent.     

Tunable terahertz metamaterial based on resonant dielectric inclusions with disturbed Mie resonance

Tunable metamaterial operating in terahertz (THz) frequency range based on dielectric cubic particles with deposited conducting resonant strip was investigated. The frequency of the first magnetic type Mie resonance depends on the electric length of the strip. It can be changed under photoexcitation or applied voltage. This method of control was used for a design of tunable double negative metamaterial based on dielectric resonant inclusions and wire medium.     

Precise measurement of the CP violation parameter sin2φ1 in B0→(cc¯)K0 decays

We present a precise measurement of the CP violation parameter sin2φ1 and the direct CP violation parameter A(f) using the final data sample of 772×10(6) BB[over ˉ] pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is reconstructed in a J/ψK(S)(0), ψ(2S)K(S)(0), χ(c1)K(S)(0), or J/ψK(L)(0) CP eigenstate and its flavor is identified from the decay products of the accompanying B meson. From the distribution of proper-time intervals between the two B decays, we obtain the following CP violation parameters: sin2φ1=0.667±0.023(stat)±0.012(syst) and A(f)=0.006±0.016(stat)±0.012(syst).     

First observation of B(s)(0) → J/ψη and B(s)(0) → J/ψη'

We report first observations of B(s)(0) → J/ψη and B(s)(0) → J/ψη'. The results are obtained from 121.4 fb(-1) of data collected at the Υ(5S) resonance with the Belle detector at the KEKB e+ e- collider. We obtain the branching fractions B(B(s)(0) → J/ψη)=[5.10±0.50(stat)±0.25(syst)(-0.79)(+1.14)(N(B(s)(*) B(s)(*))]×10(-4), and B(B(s)(0) → J/ψη')=[3.71±0.61(stat)±0.18(syst)(-0.57)(+0.83)(N(B(s)(*) B(s)(*))]×10(-4). The ratio of the two branching fractions is measured to be (B(B(s) → J/ψη'))/(B(B(s) → J/ψη))=0.73±0.14(stat)±0.02(syst).     

Highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites: Pt-free, highly efficient, and durable counter electrodes for dye-sensitized solar cells

We report the preparation of highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites which show Pt-like dye-sensitized solar cell (DSSC) efficiency and remarkable long-term durability as DSSC counter electrodes.