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The open-circuit voltage (VOC) degradation for individual subcell in 1.0 MeV electrons-irradiated GaInP/GaAs/Ge solar cells has been analyzed using electroluminescence (EL) measurements. By using the relationship between VOC degradation and electron fluence, the capture cross section of the defects induced by electron irradiation in individual subcells were determined. Furthermore, by comparing the thermal activation energy and capture cross section, a defect located at Ev+0.55 ​eV styled H2 hole trap is nonradiative recombination centre in GaInP subcell, a defect located at EC-0.96 eV styled E5 electron trap is nonradiative recombination centre in GaAs subcell, and a defect located at EC-0.38 eV styled E-center electron trap is nonradiative recombination centre in Ge subcell.

The mechanism of Rh n + (n = 1 − 3) catalyzed methane activation has been investigated theoretically. All structures on the potential energy surfaces are optimized at the density functional theory (DFT) level, using the empirically parametrized hybrid functional B3LYP. Relative energies are calculated both at the B3LYP level, using large basis sets RECP+6-311+G**. The B3LYP energies of important species on the potential energy surfaces were compared to CCSD(T) single-point energy calculations. All the three systems are two-state reactivity. For Rh+ and Rh 2 + with methane, the product are metal–carbene and hydrogen and the two reaction endothermic by 28.05 kcal/mol and 1.84 kcal/mol, respectively. While for Rh 3 + with methane, the product is a hydrogen-bridge bond molecule and the reaction exothermic by 55.30 kcal/mol so it can be performed spontaneously at room temperature. With the increase of the metal atom numbers n, the catalytic activity of Rh n + towards methane C–H bonds rise sharply, then the Rh 3 + is likely to be a better mediator than Rh+ and Rh 2 + for the activation of methane.

Dual-level direct dynamics method is employed to study the kinetics of the multiple-channel reaction CH 3 OBr + Cl − for the first time. Geometries have been optimized at the MP2 level with the 6-311+G(d,p) basis set. The minimum energy path is calculated at the same level and further refined at the QCISD(T)/6-311++G(3df,2p) level. The rate constants are obtained by using the canonical variational transition state theory incorporating small-curvature tunneling correction in the temperature range of 200–3000 K. The results show that anti -E2 elimination reaction channel is the dominant channel over the whole temperature range and the corresponding rate constants present negative temperature dependence in the low temperature range, while positive temperature dependence in the high temperature range. The three-parameter Arrhenius expression k = 2.61 × 10 −18 T 2.29 exp(1395.19/T) for the overall reaction is also given.

R-spondin 1 (Rspo1) plays an essential role in stem cell biology by potentiating Wnt signaling activity. Despite the fact that Rspo1 holds therapeutic potential for a number of diseases, its biogenesis is not fully elucidated. All Rspo proteins feature two amino-terminal furin-like repeats, which are responsible for Wnt signal potentiation, and a thrombospondin type 1 (TSR1) domain that can provide affinity towards heparan sulfate proteoglycans. Using chemical inhibitors, deglycosylase and site-directed mutagenesis, we found that human Rspo1 and Rspo3 are both N-glycosylated at N137, a site near the C-terminus of the furin repeat 2 domain, and Rspo2 is N-glycosylated at N160, a position near the N-terminus of TSR1 domain. Elimination of N-glycosylation at these sites affects their accumulation in media but have no effect on the ability towards heparin. Introduction of the N-glycosylation site to Rspo2 mutant at the position homologous to N137 in Rspo1 restored full glycosylation and rescued the accumulation defect of nonglycosylated Rspo2 mutant in media. Similar effect can be observed in the N137 Rspo1 or Rspo3 mutant engineered with Rspo2 N-glycosylation site. The results highlight the importance of N-glycosylation at these two positions in efficient folding and secretion of Rspo family. Finally, we further showed that human Rspo1 is subjected to endoplasmic reticulum (ER) quality control in N-glycan-dependent manner. While N-glycan of Rspo1 plays a role in its intracellular stability, it had little effect on secreted Rspo1. Our findings provide evidence for the critical role of N-glycosylation in the biogenesis of Rspo1.