The rechargeable Zn−air batteries as an environmentally friendly sustainable energy technology have been extensively studied. However, it is still a challenge to develop non-noble metal bifunctional catalysts with high oxygen reduction as well as oxygen evolution reaction (ORR and OER) activity and superior durability, which limit the large-scale application of rechargeable Zn−air batteries. Herein, we synthesized an ultrastable FeCo bifunctional oxygen electrocatalyst on Se-doped CNTs (FeCo/Se-CNT) via a gravity guided chemical vapor deposition (CVD) strategy. The catalyst exhibits excellent ORR (E 1/2 = 0.9 V) and OER (overpotential at 10 mA cm −2 = 340 mV) properties simultaneously, surpassing commercial Pt/C and RuO 2 /C catalysts. More importantly, the catalyst shows an unordinary stability, that is, is no obvious decrease after 30K cycles accelerated durability test for ORR and OER processes. The small potential gap (0.75 V) represents superior bifunctional ORR and OER activities of the FeCo/ Se-CNT catalyst. The FeCo/Se-CNT catalyst possesses outstanding electrochemical performance for the rechargeable liquid and flexible all-solid-state Zn−air batteries, for example, a high open circuit voltage (OCV) and peak power density of 1.543 and 1.405 V and 173.4 and 37.5 mW cm −2 , respectively.

Developing a highly efficient, easy-to-fabricate and non-noble metal electrocatalyst is vital for oxygen reduction reaction (ORR). Herein, we fabricate a single Fe sites catalyst Fe1/d-CN by developing a double-layer MOF...

Chinese hamster ovary (CHO) cells are the most widely used mammalian hosts for recombinant protein production. However, by conventional random integration strategy, development of a high-expressing and stable recombinant CHO cell line has always been a difficult task due to the heterogenic insertion and its caused requirement of multiple rounds of selection. Site-specific integration of transgenes into CHO hot spots is an ideal strategy to overcome these challenges since it can generate isogenic cell lines with consistent productivity and stability. In this study, we investigated three sites with potential high transcriptional activities: C12orf35, HPRT, and GRIK1, to determine the possible transcriptional hot spots in CHO cells, and further construct a reliable site-specific integration strategy to develop recombinant cell lines efficiently. Genes encoding representative proteins mCherry and anti-PD1 monoclonal antibody were targeted into these three loci respectively through CRISPR/Cas9 technology. Stable cell lines were generated successfully after a single round of selection. In comparison with a random integration control, all the targeted integration cell lines showed higher productivity, among which C12orf35 locus was the most advantageous in both productivity and cell line stability. Binding affinity and N-glycan analysis of the antibody revealed that all batches of product were of similar quality independent on integrated sites. Deep sequencing demonstrated that there was low level of off-target mutations caused by CRISPR/Cas9, but none of them contributed to the development process of transgene cell lines. Our results demonstrated the feasibility of C12orf35 as the target site for exogenous gene integration, and strongly suggested that C12orf35 targeted integration mediated by CRISPR/Cas9 is a reliable strategy for the rapid development of recombinant CHO cell lines.

PurposeMillennial-generation employees need to stimulate their creativity to produce innovative ideas, services and products for organizations to flourish and succeed. The main purpose of this research was to discover the mechanism through which organization identification influences employees' creativity in the Chinese organizational context. Particularly, we proposed the mediating role of work engagement and the moderating role of work values in the relationship.Design/methodology/approachA questionnaire survey was utilized to collect the data from 281 employees working in China. Hierarchical regression was utilized to analyze the data.FindingsThe findings reveal that organizational identification significantly influences the creativity of millennial employees; work engagement plays a positive mediating role between organizational identification and employee creativity. Moreover, work values of millennial generation employees, specifically utilitarian orientation, intrinsic preferences, interpersonal harmony and innovation orientation have a positive moderating effect between work engagement and employee creativity.Originality/valueThis study recognizes and analyzes the mechanism underlying the influence of organizational identification and recommends that work engagement is a crucial mediator of the complicated relationship between organizational identification and employee creativity. Consequently, this study is the key effort for millennial employees’ work values and engagement to explore employee creativity in Chinese cultural context and also suggests important theoretical and practical implications.

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Fractal behavior is scale-invariant and widely characterized by fractal dimension. However, the cor-respondence between them is that fractal behavior uniquely determines a fractal dimension while a fractal dimension can be related to many possible fractal behaviors. Therefore, fractal behavior is independent of the fractal generator and its geometries, spatial pattern, and statistical properties in addition to scale. To mathematically describe fractal behavior, we propose a novel concept of fractal topography defined by two scale-invariant parameters, scaling lacunarity (P) and scaling coverage (F). The scaling lacunarity is defined as the scale ratio between two successive fractal generators, whereas the scaling coverage is defined as the number ratio between them. Consequently, a strictly scale-invariant definition for self-similar fractals can be derived as D = log F /log P. To reflect the direction-dependence of fractal behaviors, we introduce another parameter Hxy, a general Hurst exponent, which is analytically expressed by Hxy = log Px/log Py where Px and Py are the scaling lacunarities in the x and y directions, respectively. Thus, a unified definition of fractal dimension is proposed for arbitrary self-similar and self-affine fractals by averaging the fractal dimensions of all directions in a d-dimensional space, which . Our definitions provide a theoretical, mechanistic basis for understanding the essentials of the scale-invariant property that reduces the complexity of modeling fractals.

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