Two-gap superconductivity in LaNiGa2_2 with nonunitary triplet pairing and even parity gap symmetry

The nature of the pairing states of superconducting LaNiC$_2$ and LaNiGa$_2$ has to date remained a puzzling question. Broken time reversal symmetry has been observed in both compounds and a group theoretical analysis implies a non-unitary triplet pairing state. However all the allowed non-unitary triplet states have nodal gap functions but most thermodynamic and NMR measurements indicate fully gapped superconductivity in LaNiC$_2$. Here we probe the gap symmetry of LaNiGa$_2$ by measuring the London penetration depth, specific heat and upper critical field. These measurements demonstrate two-gap nodeless superconductivity in LaNiGa$_2$, suggesting that this is a common feature of both compounds. These results allow us to propose a novel triplet superconducting state, where the pairing occurs between electrons of the same spin, but on different orbitals. In this case the superconducting wavefunction has a triplet spin component but isotropic even parity gap symmetry, yet the overall wavefunction remains antisymmetric under particle exchange. This model leads to a nodeless two-gap superconducting state which breaks time reversal symmetry, and therefore accounts well for the seemingly contradictory experimental results

Combined age and segregated kinetic model for industrial-scale penicillin fed-batch cultivation

This paper proposes a cell age model forPenicillium chrysogenum fed-batch cultivation to supply a qualitative insight into morphology-associated dynamics. The average ages of the segregated cell populations, such as growing cells, non-growing cells and intact productive cells, were estimated by this model. A combined model was obtained by incorporating the average ages of the cell sub-populations into a known but modified segregated kinetic model from literature. For simulations, no additional effort was needed for parameter identification since the cell age model has no internal parameters. Validation of the combined model was performed by 20 charges of industrial-scale penicillin cultivation. Meanwhile, only two charge-dependent parameters were required in the combined model among approximately 20 parameters in total. The model is thus easily transformed into an adaptive model for a further application in on-line state variables prediction and optimal schedulin

Thermodynamic reassessment of the Mn-Ni-Si system

Iased on the new experimental data available in the literature, the Mn-Ni-Si system has been reassessed using the CALPHAD (CALculation of PHAse Diagram) approach. Compared with the previous modeling, the τ8 and τ12 ternary phases were treated as the same phase according to the new experimental data. The Mn3Si phase was described with two sublattice model (Mn, Ni)3(Si)1. The reported new ternary phase τ was not considered in the present work. Comprehensive comparisons between the calculated and measured phase diagrams showed that a set of thermodynamic parameters of the Mn-Ni-Si system obtained in this work was more accurate than the previous one

Hierarchical porous carbons with high performance for supercapacitor electrodes

A series of hierarchical porous carbons (HPCs) were prepared by a combination of self-assembly and chemical activation. Pore-structure analysis shows that micropores can be generated within the mesopore wall of mesoporous carbon in a controllable manner during activation. As evidenced by cyclic voltammetry, galvanostatic charge/discharge cyclings and frequency response measurements, HPCs show superior capacitive performances to hard-templated ordered mesoporous carbons, which can be attributed to the generated pore surfaces that play most important role in the formation of double-layer capacitance and to their unique hierarchical porous structure that favors the fast diffusion of electrolyte ions into the pores. Of special interest is the fact that HPCs maintains 180 F/g at high-frequency of 1 Hz