Electron spin magnetism of zigzag graphene nanoribbon edge states

The electron spin states of zigzag graphene nanoribbon (ZGNR) edge play a pivotal role in the applications of graphene nanoribbons. However, the exact arrangements of the electron spins remain unclear to date. In this report, the electronic spin states of the ZGNR edge have been elucidated through a combination of quantum chemical investigation and previous electron spin resonance experiment observations. An alternating alpha and beta spin configuration of the unpaired electrons along the ZGNR edge is established in ambient condition without any external magnetic field, and the origin of the spin magnetism of the ZGNR edge is revealed. It paves a pathway for the understanding and design of graphene based electronic and spintronic devices. (C) 2014 AIP Publishing LLC

Specification of Deep Beams Affect the Shear Strength Capacity

Reinforced Concrete Deep beams researches have attracted attentions of professionals and academics due to the wider use of this type of structures in construction projects; because of characteristics in transferring significant amount of load.  Ultimate strength of deep beams has been a great challenge because of the complexity to Evaluation for this structural member. However, code provisions for capacity of beam equations are conservative.  Essentially influencing parameters are Loading and Supporting Conditions, horizontal and vertical web reinforcement, shear span-to-depth ratio,   load and support bearing plates, distribution of the reinforcement along depth of the deep beam‘s web, tension  reinforcement and compressive strength.  Least influencing parameters are bottom cover, side cover, width of the beam, distribution of vertical stirrups in the web, and aggregate size, presence the web openings. The effect of above factors on the shear capacity and behavior of RC deep beams have been reviewed. Keywords: Deep beams, D-region, Loading condition, Shear strength, Reinforcement distribution, Failure mode

Lattice structures of Larkin-Ovchinnikov-Fulde - Ferrell (LOFF) state

Starting from the Ginzburg-Landau free energy describing the normal state to Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) state transition, we evaluate the free energy of seven most common lattice structures such as stripe, square, triangular,Simple Cubic (SC), Face centered Cubic (FCC),Body centered Cubic (BCC) and Quasi-crystal (QC). We find that the stripe phase which is the original LO state, is the most stable phase. This result maybe relevant to the detection of LOFF state in some heavy fermion compounds and the pairing lattice structure of fermions with unequal populations in the BCS side of Feshbach resonance in ultra-cold atoms.Comment: 8 pages, 10 figure