cells. [3] Up to now, Pt-based electrocatalysts have been extensively considered to be the most active ORR electrocatalysts in electrochemical cell reactions. [4][5][6] Nevertheless, crustal rarity, high cost, poor stability, and methanol crossover of Ptbased materials and the sluggish kinetics of cathodic reaction greatly restrict their large-scale practical application. In this connection, a great deal of investigation has been performed based on the study of efficient non-noble metal catalysts, which mainly consists of non-noble metal compounds (e.g., oxides, nitrides, phosphide, and chalcogenides), metal-free catalysts as well as carbonitrides. [7][8][9][10][11] Then, the transition metal carbonitrides (TM-N-C, where TM represents mainly Co, Fe), obtained by carbonization various nitrogen-rich precursor (such as dicyandiamide, melamine, polyaniline, and metal-organic frameworks (MOFs)), have been widely explored to substitute precious metal catalysts because of their high catalytic activity and durability in acid or alkaline electrolyte. [12][13][14][15] In recent years, MOFs have been served as precursors to fabricate the functional nanostructured porous carbon-based electrocatalysts, which gives the credit to their excellent intrinsic characteristics, such as large specific surface area derived from the porosity and the diversity of structure and function stemmed from different metal ions and organic ligands. [16][17][18][19][20][21][22] In particular, Zn-Co bimetallic ZIFs (BMZIFs (ZIF-67 and ZIF-8)) have been extensively employed as precursors to develop efficient Co-based porous nitrogen-doped carbon catalysts, [22][23][24] which attributes to their unique merits. I) Co-N x sites can be easily produced by pyrolysis due to Co metal directly connected to N species. [25,26] II) The larger surface area derived from the pore structure, due to the evaporation of Zn at high temperature. [27,28] III) Uniform N atoms doped into the obtained carbon skeleton after calcination of Zn-ZIF. [29] However, the skeleton of MOFs was generally prone to collapse and aggregate in the pyrolysis process (>700 °C), [17,30] resulting in fewer pore structures, which greatly reduces the electrochemical performance. Therefore, it is urgent and significant to assist the MOFs with quite a few novel substrates (e.g., layered double hydroxides (LDHs), [30,31] graphene, [21] carbon cloth, [32] polyacrylonitrile (PAN) nanofibers, [33] and Te nanowires [29] ) to achieve the The exploitation of high-efficiency, cost-effective, and stable oxygen reduction reaction (ORR) electrocatalysts is extremely critical for energy storage and conversion technology. The transition metal carbonitrides have been investigated as an alternative to precious metal-based catalysts. Here, a series of uniform Co nanoparticles encapsulated in nitrogen-doped porous carbon fibers (Co@N-PCFs for brevity) are designed and synthesized by directly carbonizing the Zn x Co 1-x -zeolitic imidazolate frameworks@polyacrylonitrile (Zn x Co 1-x -ZIFs@PAN) electrospun nanofiber...

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Organisms cope with environmental stressors by behavioral, morphological, and physiological adjustments. Documentation of such adjustments in the wild provides information on the response space in nature and the extent to which behavioral and bodily adjustments lead to appropriate performance effects. Here we studied the morphological and digestive adjustments in a staging population of migrating Great Knots Calidris tenuirostris in response to stark declines in food abundance and quality at the Yalu Jiang estuarine wetland (northern Yellow Sea, China). At Yalu Jiang, from 2011 to 2017 the densities of intertidal mollusks, the food of Great Knots, declined 15‐fold. The staple prey of Great Knots shifted from the relatively soft‐shelled bivalve Potamocorbula laevis in 2011–2012 to harder‐shelled mollusks such as the gastropod Umbonium thomasi in 2016–2017. The crushing of the mollusks in the gizzard would require a threefold to 11‐fold increase in break force. This was partially resolved by a 15% increase in gizzard mass which would yield a 32% increase in shell processing capacity. The consumption of harder‐shelled mollusks was also accompanied by reliance on regurgitates to excrete unbreakable parts of prey, rather than the usual intestinal voidance of shell fragments as feces. Despite the changes in digestive morphology and strategy, there was still an 85% reduction in intake rate in 2016–2017 compared with 2011–2012. With these morphological and digestive adjustments, the Great Knots remaining faithful to the staging site to a certain extent buffered the disadvantageous effects of dramatic food declines. However, compensation was not complete. Locally, birds will have had to extend foraging time and use a greater daily foraging range. This study offers a perspective on how individual animals may mitigate the effects of environmental change by morphological and digestive strategies and the limits to the response space of long‐distance migrating shorebirds in the wild.

Flame-retarding oligo(carbonate-ether) diols were successfully prepared with considerable efficiency by copolymerization of propylene oxide (PO) and carbon dioxide (CO 2 ) using a Zn 3 [Co(CN) 6 ] 2 -based double metal cyanide complex (DMC) in the presence of bisphenol A (BPA) as a chain transfer agent (CTA). The effects of molar ratio of PO to BPA, temperature, pressure and reaction time on the copolymerization were systematically investigated. The number average molecular weight (M n ) of the oligo(carbonateether) diols is in good linear relationship to the molar ratio of PO to BPA and can be facility tuned in the range of 1000-2400 g mol À1 by adjusting reaction temperature and reaction time at fixed PO/BPA ¼ 25.0. Lower temperature and higher CO 2 pressure were beneficial for incorporating CO 2 into the oligomer chain. The oligomer with a carbonate (CU) of 42% and M n of 2400 g mol À1 is obtained at 2.0 MPa CO 2 pressure and 75 C with productivity of 2.4 kg g À1 DMC within 6 h.

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