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•MD simulation can reveal the effect of moisture on interfacial behaviors of geopolymer-aggregate interaction;•Wetting characteristics of aggregate surfaces were elucidated and ...compared.•The interfacial mechanism of geopolymer-aggregate with the participation of moisture was explained.•Mechanical behaviors of geopolymer-water-aggregate interface were investigated using peeling and shearing simulation.
The interaction between geopolymer and aggregate largely determines the mechanical properties and durability of the geopolymer concrete. The effects of moisture on interfacial behavior of geopolymer-aggregate interaction are poorly understood, especially at molecular level. Herein, molecular dynamics (MD) simulation was employed to reveal the interactive behaviors of geopolymer-aggregate interfacial system with the participation of moisture. Full atomistic models adopted for MD simulations were constructed using the sodium aluminum silicate hydrate (N-ASH) gel model and the main chemical components of the aggregates, SiO2 and CaCO3. Then the wetting characteristics of aggregate surfaces, interfacial characteristics and mechanical behaviors of the geopolymer-aggregate interfacial systems containing interfacial moisture were elucidated and compared. It is found that the SiO2 surface is hydrophobic while the CaCO3 surface exhibits hydrophilic characteristics. Interfacial moisture participates in electrostatic interaction, H-bond interaction and coordination interaction in geopolymer-aggregate interface area. Appropriate interfacial water is beneficial to the interfacial interaction of geopolymer-aggregate system, but excessive water will increase the risk of interfacial failure. The interfacial moisture affects the diffusion behavior of water molecules and Na+ ions in geopolymer to the interfacial region, and the formation of H-bonds and coordination bonds at the interface. Mechanically, with the participation of interfacial moisture, the geopolymer-SiO2 interfacial system possesses stronger tensile strength, and a greater risk of shear failure than that of geopolymer-CaCO3. The above atomic-level findings may facilitate a better design and fabrication of geopolymer concrete in engineering.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Changes in tissue structure, rheological property and water content of dry abalone meat in the process of water restoration were studied. The weight and volume of dry abalone meat increased with ...water restoration. When observed under a light microscope, structural change in myofibrils was obvious and a distinct network was found. When water restoration time increased from 24 h to 72 h, the instantaneous modulus E0 and viscosity η1 increased, whereas the rupture strength and relaxation time （τ1） were reduced. There were no significant changes of rheological parameters （E0, η1,τ1, rupture strength） from 72 h to 96 h of water restoration. Therefore, the dry abalone meat was swollen enough at the time of 72 h. The rheological parameters were obviously influenced by the structural changes.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Neuromorphic perception systems inspired by biology have tremendous potential in efficiently processing multi-sensory signals from the physical world, but a highly efficient hardware element ...capable of sensing and encoding multiple physical signals is still lacking. Here, we report a spike-based neuromorphic perception system consisting of calibratable artificial sensory neurons based on epitaxial VO
2
, where the high crystalline quality of VO
2
leads to significantly improved cycle-to-cycle uniformity. A calibration resistor is introduced to optimize device-to-device consistency, and to adapt the VO
2
neuron to different sensors with varied resistance level, a scaling resistor is further incorporated, demonstrating cross-sensory neuromorphic perception component that can encode illuminance, temperature, pressure and curvature signals into spikes. These components are utilized to monitor the curvatures of fingers, thereby achieving hand gesture classification. This study addresses the fundamental cycle-to-cycle and device-to-device variation issues of sensory neurons, therefore promoting the construction of neuromorphic perception systems for e-skin and neurorobotics.
The exploration of new highly efficient and durable for the oxidation of amines to imines has gained immense attention. In this work, a new polyoxometalate-based metal–organic framework (POMOF) {Cu
4
...(C
26
H
16
N
4
O
4
)
4
(CH
3
CN)
2
SiW
12
O
40
}·4H
2
O (SiW-Cu-DPNDI) was constructed with a catalytic oxidant Keggin-type SiW
12
O
40
4−
anion, a photosensitizer N,N'-bis(4-pyridylmethyl)naphthalene diimide (DPNDI) ligand, and a Cu(I) cation via self-assembling. Although single-crystal X-ray diffraction, power X-ray diffraction (PXRD), infrared (IR) spectroscopy, etc., were employed to confirm the hierarchical structure of SiW-Cu-DPNDI, critical analyses through, such as the magnetic susceptibility measurements, the Mott–Schottky measurements, and the electron spin resonance studies were successfully applied to elucidate the properties of POMOF. SiW-Cu-DPNDI was highly active in the heterogeneous photocatalysis of the oxidation of amines to imines under mild conditions. Additionally, this catalyst exhibited high stability and reusability without losing its activity during the photocatalysis. The possible mechanism of the oxidation coupling was extensively investigated under visible-light (Vis)-irradiation.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Drought is a complex hazard, and it has an impact on agricultural, ecological, and socio-economic systems. The vegetation condition index (VCI), which is derived from remote-sensing data, has been ...widely used for drought monitoring. However, VCI based on the normalized difference vegetation index (NDVI) does not perform well in certain circumstances. In this study, we examined the utility of the vegetation index based on the universal pattern decomposition method (VIUPD) based VCI for drought monitoring in various climate divisions across the continental United States (CONUS). We compared the VIUPD-derived VCI with the NDVI-derived VCI in various climate divisions and during different sub-periods of the growing season. It was also compared with other remote-sensing-based drought indices, such as the temperature condition index (TCI), precipitation condition index (PCI) and the soil moisture condition index (SMCI). The VIUPD-derived VCI had stronger correlations with long-term in situ drought indices, such as the Palmer Drought Severity Index (PDSI) and the standardized precipitation index (SPI-3, SPI-6, SPI-9, and SPI-12) than did the NDVI-derived VCI, and other indices, such as TCI, PCI and SMCI. The VIUPD has considerable potential for drought monitoring. As VIUPD can make use of the information from all the observation bands, the VIUPD-derived VCI can be regarded as an enhanced VCI.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
•Three polysaccharides (ARPPs) were isolated from Anoectochilus roxburghii.•The antioxidant and hepatoprotective activities of ARPPs were investigated.•ARPP80 showed high antioxidant and ...hepatoprotective activities.•Findings showed that ARPPs have potential beneficial effects in functional foods.
The physicochemical properties (molecular weights and monosaccharide compositions), antioxidant and hepatoprotective activities of polysaccharides (ARPPs: ARPP30, ARPP60 and ARPP80) isolated from Anoectochilus roxburghii were investigated. ARPP80 exhibited relatively strong antioxidant activities in a concentration-dependent manner. In mice subjected to carbon tetrachloride-induced hepatotoxicity, ARPP80 pretreatment significantly (p<0.01) reduced the levels of aspartate and alanine amino transferases and malonyldialdehyde, prominently (p<0.01) restored the levels of superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione in serum or liver homogenate. These hepatoprotective effects were comparable to those of the standard drug silymarin at the same dose (200mg/kg). The study clearly demonstrated that ARPPs, especially ARPP80, might be suitable as functional foods or hepatoprotective drugs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The electrocatalytic urea oxidation reaction (UOR) can be utilized as an alternative anodic reaction for water electrolysis to provide more economic electrons and high-efficiency H
2
production. ...Nonetheless, electrocatalytic urea oxidation still suffers from its high energy barrier, sluggish kinetics and intricate reaction mechanism. Low-cost and efficient electrocatalysts towards the UOR with satisfactory activity and long lifespan are still lacking, and the underlying electrochemical mechanisms are not fully understood yet. Herein, an electrocatalyst of heterostructured cobalt-and-nickel-based-sulfides anchored on nickel foam (Co-Ni-S@NF) with a designed interface between Ni
3
S
2
and Co
9
S
8
was designed and synthesized
via
a one-step solvothermal method, exhibiting excellent urea electrooxidation activity (100 mA cm
−2
at 1.35 V
vs.
reversible hydrogen electrode) and stability (100 h at 100 mA cm
−2
). Detailed structural and compositional characterization, along with electrochemical measurements reveals that the interface induced charge transfer between the strongly coupled Ni
3
S
2
and Co
9
S
8
could enhance the catalytic activity and stability of the hybrid material.
In situ
Raman and
in situ
Fourier transform infrared measurements clarify the voltage-driven self-reconstruction process based on different catalyst surfaces and help to understand the reaction pathway on the basis of the detected intermediated species. The ultrahigh UOR performance of Co-Ni-S@NF can be attributed to the incorporated Co element accelerating the structural evolution of Ni
3
S
2
and facilitating the formation of high-valent Ni species, which are highly relevant to urea decomposition efficiency. The Co-Ni-S@NF electrode contributes to the improved C-N and N-H bond cleavage in urea and achieves a high-speed production of CO
2
, resulting in a higher activity upon the UOR. DFT calculations indicate sufficient charge exchange and defect formation at the heterointerface which boost the urea oxidation reaction. This work opens a new avenue to develop efficient electrocatalysts with a designed heterostructure and interface for electrochemical hydrogen production.
The electrocatalytic urea oxidation reaction (UOR) can be utilized as an alternative anodic reaction for water electrolysis to provide more economic electrons and high-efficiency H
2
production.
Distiller’s grains resourcing is a crucial problem for the sustainable development of the Chinese Baijiu industry. In order to improve the protein utilization of distiller’s grains. In this study, ...distiller’s grains pretreated by wet crushing combined with amylase/cellulase were further hydrolyzed with neutral protease combined with papain at 50 °C for 3 h. The hydrolysates were decolorized by 1% coconut shell activated carbon for 15 min, and separated and purified by macroporous resin and Sephadex gel to yield peptide fractions (F1, F2, F3 and F4). The F3 fraction with the highest radical scavenging activity was analyzed by nano-LC-MS/MS and peptidomics to identify peptides. Three peptides (especially newly discovered AAHVLAAAFL) displayed strong alcohol solubility and antioxidant activity and were stably bound to key regulatory pathway receptors (Keap1-Nrf2) and myeloperoxidase (MPO), further elucidating molecular mechanism of anti-oxidation. These findings provided knowledge for potential functional peptide candidates and facilitates the high-value commercial development of distiller’s grains.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Most catalysts cannot accelerate uninterrupted conversion of polysulfides, resulting in poor long-cycle and high-loading performance of lithium-sulfur (Li-S) batteries. Herein, rich p-n junction CoS
.../ZnS heterostructures embedded on N-doped carbon nanosheets are fabricated by ion-etching and vulcanization as a continuous and efficient bidirectional catalyst. The p-n junction built-in electric field in the CoS
/ZnS heterostructure not only accelerates the transformation of lithium polysulfides (LiPSs), but also promotes the diffusion and decomposition for Li
S the from CoS
to ZnS avoiding the aggregation of lithium sulfide (Li
S). Meanwhile, the heterostructure possesses a strong chemisorption ability to anchor LiPSs and superior affinity to induce homogeneous Li deposition. The assembled cell with a CoS
/ZnS@PP separator delivers a cycling stability with a capacity decay of 0.058% per cycle at 1.0 C after 1000 cycles, and a decent areal capacity of 8.97 mA h cm
at an ultrahigh sulfur mass loading of 6 mg cm
. This work reveals that the catalyst continuously and efficiently converts polysulfides via abundant built-in electric fields to promote Li-S chemistry.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Hydrolysable tannins (HTs) are useful secondary metabolites that are responsible for pharmacological activities and astringent taste, flavor, and quality in fruits. They are also the main polyphenols ...in Canarium album L. (Chinese olive) fruit, an interesting and functional fruit that has been cultivated for over 2000 years. The HT content of C. album fruit was 2.3–13 times higher than that of berries with a higher content of HT. 1-galloyl-β-d-glucose (βG) is the first intermediate and the key metabolite in the HT biosynthesis pathway. It is catalyzed by UDP-glucosyltransferases (UGTs), which are responsible for the glycosylation of gallic acid (GA) to form βG. Here, we first reported 140 UGTs in C. album. Phylogenetic analysis clustered them into 14 phylogenetic groups (A, B, D–M, P, and Q), which are different from the 14 typical major groups (A~N) of Arabidopsis thaliana. Expression pattern and correlation analysis showed that UGT84A77 (Isoform0117852) was highly expressed and had a positive correlation with GA and βG content. Prokaryotic expression showed that UGT84A77 could catalyze GA to form βG. These results provide a theoretical basis on UGTs in C. album, which will be helpful for further functional research and availability on HTs and polyphenols.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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