In-Plane Chemical Ordering (Mo2/3 R1/3 )2 AlB2 (R = Tb, Dy, Ho, Er, Tm, and Lu) i-MAB Phases and their Two-Dimensional Derivatives (MBene): Synthesis, Structure, Magnetic, and Supercapacitor Performance.

A family of hexagonal in-plane chemical ordering (Mo2/3 R1/3 )2 AlB2 (R = Tb, Dy, Ho, Er, Tm, and Lu) i-MAB phases are synthesized with R-3m hexagonal structure. The i-MAB phases with R = Tb to Tm are considered to have a nonlinear ferromagnetic-like coupling magnetic ground state with gradually weakened magnetocrystalline anisotropy due to variant R-R distances and 4f electrons. Their 2D derivatives (2D-MBene) with rare-earth (R) atom vacancies are obtained by chemical etching. The delamination solvent, surface functional terminations, and chemical bond of 2D-MBene can be modified by one-step nitridation in environment-friendly nitrogen instead of ammonia. A phase conversion is caused by nitridation at 973 K from 2D-MBene to Mo2 N, leading to the optimized specific capacitance of 229 F g-1 . Besides exploring more rare-earth-containing laminated boride systems, this work also demonstrates the promising application of their 2D derivatives with R vacancies in supercapacitors.

Vanadium Oxides with Amorphous-Crystalline Heterointerface Network for Aqueous Zinc-Ion Batteries.

Rechargeable aqueous Zn-VOx batteries are attracting attention in large scale energy storage applications. Yet, the sluggish Zn2+ diffusion kinetics and ambiguous structure-property relationship are always challenging to fulfil the great potential of the batteries. Here we electrodeposit vanadium oxide nanobelts (VO-E) with highly disordered structure. The electrode achieves high capacities (e.g., ≈5 mAh cm-2 , 516 mAh g-1 ), good rate and cycling performances. Detailed structure analysis indicates VO-E is composed of integrated amorphous-crystalline nanoscale domains, forming an efficient heterointerface network in the bulk electrode, which accounts for the good electrochemical properties. Theoretical calculations indicate that the amorphous-crystalline heterostructure exhibits the favorable cation adsorption and lower ion diffusion energy barriers compared to the amorphous and crystalline counterparts, thus accelerating charge carrier mobility and electrochemical activity of the electrode.

Quantum transmission through the n-p-n heterojunction of massive 8-Pmmnborophene.

We investigate the quantum transmission through the n-p-n heterojunction of massive 8-Pmmnborophene. It is found that the Dirac mass of the electron interacts nontrivially with the anisotropy of the 8-Pmmnborophene, leading to the occurrence of new transmission behaviors in this n-p-n heterojunction. Firstly, the effective energy range of nonzero transmission can be reduced but deviates from the mass amplitude, which induces the further controllability of the transmission property. Secondly, even if the equal-energy surfaces in the p and n parts do not encounter in thek-space, finite transmission is allowed to occur as well. In addition, the existence of Dirac mass can change the reflection manner from the retroreflection to the specular reflection under appropriate conditions. The findings in this work can be helpful in describing the quantum transport properties of the heterojunction based on 8-Pmmnborophene.

Fabrication, characterization, and magnetic properties of exchange-coupled porous BaFe8Al4O19/Co0.6Zn0.4Fe2O4 nanocomposite magnets.

Fabrication of exchange-coupled nanocomposite magnets has been considered to be the most effective method to achieve the high energy product for advanced permanent magnet applications. In this work, we report a facile auto-combustion synthesis to prepare porous exchange-coupled hard-soft ferrite-based magnetic BaFe8Al4O19-x wt% Co0.6Zn0.4Fe2O4 nanocomposites (where x = 10, 20, 30 and 40), which realize an effective exchange-coupled interaction when the x value is less than 30. Compared with BaFe8Al4O19, the optimized nanocomposite with 20% Co0.6Zn0.4Fe2O4 shows a 70.3% increase in Ms and a 60.4% enhancement in Mr and maintains a high Hc value of 8.8 kOe. The work demonstrates that the auto-combustion synthesis is a promising approach for the fabrication of high-performance ferrite-based permanent magnets.

Isolation and enrichment of Ginkgo biloba extract by a continuous chromatography system.

In this study, an effective method was developed for the isolation and enrichment of Ginkgo biloba extract by continuous chromatography system. The adsorption and desorption ratio of flavonoids as main index, the best macroporous resin was screened out from six resins by static adsorption and desorption tests. At the same time the adsorption and desorption parameters were optimized by dynamic adsorption and desorption tests. Under optimal parameters, five operations consisting of loading, washing, desorbing, regenerating, and balancing were integrated across the continuous chromatography system for the purpose of refining 66 L of crude extract solution. The results were as follows, 198.22 g of Ginkgo biloba extracts was produced, which contained 65.83 g of flavonoids and 15.44 g of lactones. The content of flavonoids and lactones increased from 2.76 and 0.72% in the crude extract to 33.21 and 7.79%, with a recovery yield of 91.26 and 81.21%. Methodology validation showed that the proposed method had high stability and reproducibility. Compared with the traditional macroporous resin method, the proposed method had a short processing time and low solvent consumption. Our studies indicated that the newly developed method is an effective procedure for the isolation and enrichment of Ginkgo biloba extract.

Solid-state nanopore based biomimetic voltage gated ion channels.

Voltage gating is essential to the computational ability of neurons. We show this effect can be mimicked in a solid-state nanopore by functionalizing the pore interior with a redox active molecule. We study the integration of an active biological molecule-a quinone-into a solid state nanopore, and its subsequent induced voltage gating. We show that the voltage gating effect mimics biological gating systems in its classic sigmoidal voltage response, unlike previous synthetic voltage gating systems. Initially, the quinone undergoes a reduction due to radicals in the bulk solution, and is converted to the hydroquinone state. Upon deprontonation the hydroquinone then acts as a charged nanomechanical arm, which opens the channel under the applied potential. We establish that the quinone gains a single net charge when the pH inside of the nanopore reaches its pKa value, and explore factors that influence the net pH in the middle of the pore. Using a combination of theory, experiment and simulation, we conclude that concentration polarization and a shift of the pH inside of the channel is the main cause of this gating effect.

Rapid Metal -free Macromolecular Coupling via in situ Nitrile Oxide-Activated Alkene Cycloaddition.

Nitrile oxide 1,3 dipolar cycloaddition is a simple and powerful coupling methodology. However, the self-dimerization of nitrile oxides has prevented the widespread use of this strategy for macromolecular coupling. By combining an in situ nitrile oxide generation with a highly reactive activated dipolarophile, we have overcome these obstacles and present a metal-free macromolecular coupling strategy for the modular synthesis of several ABA triblock copolymers. Nitrile oxides were generated in situ from chloroxime terminated poly(dimethylsiloxane) B-blocks and coupled with several distinct hydrophilic (poly(2-methyloxazoline) and poly(ethylene glycol)), and poly(N-isopropylacrylamide) or hydrophobic (poly(L-lactide) A-blocks terminated in activated dipolarophiles in a rapid fashion with high yield. This methodology overcomes many drawbacks of previously reported metal-free methods due to its rapid kinetics, versatility, scalability, and ease of introduction of necessary functionality. Nitrile oxide cycloaddition should find use as an attractive macromolecular coupling strategy for the synthesis of biocompatible polymeric nanostructures.

Nd(2)Fe(14)B/FeCo anisotropic nanocomposite films with a large maximum energy product.

Anisotropic Nd(2) Fe(14) B/Fe(67) Co(33) nanocomposite thin films are successfully fabricated. The multilayer composite films comprise Nd-rich shell-enveloped Nd(2) Fe(14) B grains and a Fe(67) Co(33) phase. The strong (001) texture of the Nd(2) Fe(14) B grains and the presence of exchange-coupled Fe(67) Co(33) lead to a high remanence and the presence of the Nd-rich shell gives rise to a high coercivity. The unique nanocomposite microstructure provides hints for developing rare-earth-lean high-performance magnets.

High-hole-mobility field-effect transistors based on co-benzobisthiadiazole-quaterthiophene.

High-mobility organic thin film transistors based on a benzobisthiadiazole-containing polymer are presented together with their morphological and optical properties. A very tight packing pattern of "edge-on" orientated polymer chains is observed in their thin films after annealing, and the hole mobility of this polymer is up to 2.5 cm(2) V(-1) s(-1) .

6,13-dibromopentacene [2,3:9,10]-bis(dicarboximide): a versatile building block for stable pentacene derivatives.

6,13-Dibromopentacene [2,3:9,10]-bis(dicarboximide) (1) was synthesized for the first time by using in situ generated benzo[1,2-c:4,5-c']difuran as a key intermediate. Compound 1 exhibits good photostability in comparison to other pentacene derivatives and it can be further functionalized by Pd-catalyzed coupling reactions to give a series of soluble and stable functional pentacenes.

X- and H-shape two dimensional conjugated oligomers with anthracene as the node.

X- and H-shape two-dimensional (2D) conjugated oligomers (X- and H-mers) and relevant model compounds have been synthesized through the introduction of different conjugated segments at the 9,10 and 2,6-positions of anthracene, and their properties were studied in detail. Comparing with the model compounds, the X- and H-mers are featured with broader absorption spectra and narrower energy bandgaps. Computational studies on the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) also indicate that these X- and H-mers are 2D conjugated. Solution processed bulk heterojunction (BHJ) solar cells with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as the acceptor material exhibited the power conversion efficiency (PCE) up to 0.53 %.

The first soluble conjugated poly(2,6-anthrylene): synthesis and properties.

The first soluble conjugated poly(2,6-anthrylene) with 9,10-diphenyl-anthracene as the repeating unit is reported; photophysical studies reveal that this polymer represents a novel well-conjugated system.

Synthesis and characterization of soluble oligo (9,10-bisalkynylanthrylene)s.

[structure: see text] Soluble oligo(9,10-bialkynylanthrylene)s up to pentamers were synthesized by means of the Suzuki coupling reaction. A solution processed thin film field-effect transistor from pentamer OA-5b shows a charge carrier mobility of 2.95 x 10(-)(3) cm(2)/V x s.