[Seasonal differences in vegetative regeneration of three desiccation-tolerant mosses in the Loess Plateau and its mechanism]. / é»„åœŸé«˜åŽŸä¸‰ç§è€å¹²è—“è¥å »ç¹æ®–çš„å­£èŠ‚å·®å¼‚åŠæœºç†.

Bryophytes have been used in many fields, such as landscaping and soil and water conservation. How-ever, few studies focused on moss regeneration and its influencing factors, which retards the application study. Three common desiccation-tolerant mosses (Barbula unguiculata, Didymodon vinealis, and Didymodon tectorum) in the Loess Plateau region were collected across four seasons. We measured vigor index of new shoots, representing vegetative regeneration capacity, and physiological indices, which included the contents of chlorophyll, soluble sugar, soluble protein and malondialdehyde (MDA), to determine seasonal differences in regeneration capacity and physiological characteristics of the three mosses, as well as their relationships. The results showed that, 1) vegetative regeneration of mosses showed significantly seasonal differences. The vigor index of the three mosses in summer were the lowest, averagely decreased by 56.1%, 48.4%, and 10.1% compared with that in autumn, winter, and spring, respectively. The vigor index of the three mosses in the same season showed interannual variation. 2) There were considerable differences in the regeneration capacity of mosses across species. D. tectorum and B. unguiculata had the highest and lowest vigor indices, respectively. In terms of regeneration capacity, B. unguiculata had the largest seasonal and interannual variations. 3) The physiological characteristics of mosses had seaonal variations. The mosses collected in the summer had the highest MDA content but the lowest contents of soluble sugar and soluble protein. 4) Seasonal variations in desiccation-tolerant moss regeneration were mostly due to soluble sugar. Our results showed seasonal variations of vegetative propagation capacity, and highlighted the role of soluble sugar as a critical factor influencing vegetative propagation of mosses. These findings could provide scientific support for moss protection and artificial cultivation.

Dual-carbon coupled Co5.47N composites for capacitive lithium-ion storage.

Transition metal nitrides are of great interest as potential anodes for lithium-ion batteries (LIBs) owing to their high theoretical capacity. However, poor cycling stability and rate performance greatly hinder their practical applications. To better alleviate these problems, a unique 3D hierarchical nanocomposite constructed by dual carbon-coated Co5.47N nano-grains wrapped with carbon and reduced graphene oxide (Co5.47N@C@rGO) was synthesized through one-step simultaneous nitridation and carbonization of zeolitic imidazolate frameworks@GO precursor. The 3D hierarchical Co5.47N@C@rGO composite can combine the good conductivity and mechanical strength of rGO and a high theoretical capacity of Co5.47N. When explored as anode material for LIBs, Co5.47N@C@rGO exhibits a high reversible capacity of ~860 mAh g-1 at a current density of 1.0 A g-1 after 500 cycles and excellent high-rate capability (665 and 573 mAh g-1 at current densities of 3.2 and 6.4 A g-1, respectively). The excellent electrochemical performance of Co5.47N@C@rGO can be ascribed to its hierarchically porous structure and the synergistic effect between Co5.47N nano-grains and rGO.

Imparting surface hydrophobicity to metal-organic frameworks using a facile solution-immersion process to enhance water stability for CO2 capture.

The water sensitivity of metal-organic frameworks (MOFs) poses a critical issue for their large-scale applications. One effective method to solve this is to provide MOFs with a hydrophobic surface. Herein, we develop a facile solution-immersion process to deposit a hydrophobic coating on the MOFs' external surface without blocking their intrinsic pores. The water contact angle of the surface hydrophobic (SH) MOFs is ∼146°. The hydrophobic coating not only greatly enhances MOFs' water stability but also provides durable protection against the attack of water molecules. When exposed to liquid water, the SH samples well retain their crystal structure, morphology, surface area and CO2 uptake capacity. However, the as-synthesized (AS) samples nearly collapse and lose their porosity as well as CO2 uptake capacity after the same exposure. This study opens up a new avenue for the MOFs' application of gas sorption in the presence of water.

Bioinspired multifunctional vanadium dioxide: improved thermochromism and hydrophobicity.

Vanadium dioxide (VO2) films with moth-eye nanostructures have been fabricated to enhance the thermochromic properties with different periodicity (d) to achieve antireflection (AR). It is revealed that the films with smaller d (210 and 440 nm) could increase both the luminous transmission (Tlum) and infrared transmission (TIR) at 25 and 90 °C, as the d is smaller than the given wavelength and the gradient refractive index produces antireflection. The average Tlum and TIR of VO2 increase with decreasing d. Compared with the planar film, the AR sample with periodicity of 210 nm and thickness of 140 nm can offer approximately 10% enhancement of Tlum and 24.5% increase in solar modulation (ΔTsol). With the addition of hydrophobic overcoat on the patterned VO2, ∼120° contact angle could be achieved. The present approach can tailor the optical transmittance in different wavelengths at high and low temperature together with self-cleaning, opening new avenues for producing hydrophobic VO2 with enhanced thermochromic properties for smart window applications.

Porous Spinel Zn(x)Co(3-x)O(4) hollow polyhedra templated for high-rate lithium-ion batteries.

Nanostructured metal oxides with both anisotropic texture and hollow structures have attracted considerable attention with respect to improved electrochemical energy storage and enhanced catalytic activity. While synthetic strategies for the preparation of binary metal oxide hollow structures are well-established, the rational design and fabrication of complex ternary metal oxide with nonspherical hollow features is still a challenge. Herein, we report a simple and scalable strategy to fabricate highly symmetric porous ternary ZnxCo3-xO4 hollow polyhedra composed of nanosized building blocks, which involves a morphology-inherited and thermolysis-induced transformation of heterobimetallic zeolitic imidazolate frameworks. When tested as anode materials for lithium-ion batteries, these hollow polyhedra have exhibited excellent electrochemical performance with high reversible capacity, excellent cycling stability, and good rate capability.