Developing high‐performance and cost‐effective bifunctional electrocatalysts for large‐scale water electrolysis is desirable but remains a significant challenge. Most existing nano‐ and ...micro‐structured electrocatalysts require complex synthetic procedures, making scale‐up highly challenging. Here, a heterogeneous Ni2P‐Fe2P microsheet is synthesized by directly soaking Ni foam in hydrochloric acid and an iron nitrate solution, followed by phosphidation. Benefiting from high intrinsic activity, abundant active sites, and a superior transfer coefficient, this self‐supported Ni2P‐Fe2P electrocatalyst shows superb catalytic activity toward overall water splitting, requiring low voltages of 1.682 and 1.865 V to attain current densities of 100 and 500 mA cm−2 in 1 m KOH, respectively. Such catalytic performance is superior to the benchmark IrO2 || Pt/C pair and also places this electrocatalyst among the best bifunctional catalysts reported thus far. Furthermore, its enhanced corrosion resistance and hydrophilic surface make it suitable for seawater splitting. It is able to achieve current densities of 100 and 500 mA cm−2 in 1 m KOH seawater at voltages of 1.811 and 2.004 V, respectively, which, together with its robust durability, demonstrates its great potential for realistic seawater electrolysis. This work presents a general and economic approach toward the fabrication of heterogeneous metallic phosphide catalysts for water/seawater electrocatalysis.
A novel and economic strategy is developed to synthesize heterogeneous bimetallic phosphide Ni2P‐Fe2P as an efficient bifunctional catalyst for water/seawater splitting. Benefiting from high intrinsic activity, abundant active sites, and a superior transfer coefficient, this self‐supported Ni2P‐Fe2P electrocatalyst shows superb catalytic activity toward overall water splitting, together with its robust durability.
We present herein a highly efficient atroposelective synthesis of axially chiral 1,1′‐bipyrroles bearing an N−N linkage from simple hydrazine and 1,4‐diones. Further product derivatizations led to ...axially chiral bifunctional compounds with high potential in asymmetric catalysis. For this chrial phosphoric acid (CPA)‐catalyzed double Paal–Knorr reaction, an intriguing Fe(OTf)3‐induced enantiodivergence was also observed.
A highly efficient atroposelective synthesis of axially chiral 1,1′‐bipyrroles bearing an N−N linkage from simple hydrazine and 1,4‐diones is presented. Further product derivatizations led to axially chiral bifunctional compounds with high potential in asymmetric catalysis. For this chiral phosphoric acid (CPA)‐catalyzed double Paal–Knorr reaction, an intriguing Fe(OTf)3‐induced enantiodivergence was also observed.
Seawater is one of the most abundant natural resources on our planet. Electrolysis of seawater is not only a promising approach to produce clean hydrogen energy, but also of great significance to ...seawater desalination. The implementation of seawater electrolysis requires robust and efficient electrocatalysts that can sustain seawater splitting without chloride corrosion, especially for the anode. Here we report a three-dimensional core-shell metal-nitride catalyst consisting of NiFeN nanoparticles uniformly decorated on NiMoN nanorods supported on Ni foam, which serves as an eminently active and durable oxygen evolution reaction catalyst for alkaline seawater electrolysis. Combined with an efficient hydrogen evolution reaction catalyst of NiMoN nanorods, we have achieved the industrially required current densities of 500 and 1000 mA cm
at record low voltages of 1.608 and 1.709 V, respectively, for overall alkaline seawater splitting at 60 °C. This discovery significantly advances the development of seawater electrolysis for large-scale hydrogen production.
Behavioral research has established that humans implicitly tend to hold a positive view toward themselves. In this study, we employed the event-related potential (ERP) technique to explore neural ...manifestations of positive implicit self-esteem using the Go/Nogo association task (GNAT). Participants generated a response (Go) or withheld a response (Nogo) to self or others words and good or bad attributes. Behavioral data showed that participants responded faster to the self paired with good than the self paired with bad, whereas the opposite proved true for others, reflecting the positive nature of implicit self-esteem. ERP results showed an augmented N200 over the frontal areas in Nogo responses relative to Go responses. Moreover, the positive implicit self-positivity bias delayed the onset time of the N200 wave difference between Nogo and Go trials, suggesting that positive implicit self-esteem is manifested on neural activity about 270 ms after the presentation of self-relevant stimuli. These findings provide neural evidence for the positivity and automaticity of implicit self-esteem.
Increased vascular permeability facilitates metastasis. Emerging evidence indicates that secreted microRNAs (miRNAs) may mediate the crosstalk between cancer and stromal cells. To date, whether and ...how secreted miRNAs affect vascular permeability remains unclear. Based on deep sequencing and quantitative PCR, we found that higher level of serum miR‐103 was associated with higher metastasis potential of hepatocellular carcinoma (HCC). The in vitro endothelial permeability and transendothelial invasion assays revealed that the conditioned media or exosomes derived from high miR‐103‐expressing hepatoma cells increased the permeability of endothelial monolayers, but this effect was attenuated if exosome secretion of hepatoma cells was blocked by silencing ALIX and HRS or if miR‐103 within hepatoma or endothelial cells was antagonized. Most importantly, pretreating endothelial monolayers with exosomes that were from stable miR‐103‐expressing hepatoma cells facilitated the transendothelial invasion of tumor cells, and this role of exosomes was abrogated by inhibiting miR‐103 in endothelial cells. Further in vivo analyses disclosed that mice with xenografts of stable miR‐103‐expressing hepatoma cells exhibited higher vascular permeability in tumor, higher level of exosomal miR‐103 and greater number of tumor cells in blood circulation, and increased rates of hepatic and pulmonary metastases, compared to control mice. Mechanism investigations revealed that hepatoma cell‐secreted miR‐103 could be delivered into endothelial cells via exosomes, and then attenuated the endothelial junction integrity by directly inhibiting the expression of VE‐Cadherin (VE‐Cad), p120‐catenin (p120) and zonula occludens 1. Moreover, miR‐103 could also promote tumor cell migration by repressing p120 expression in hepatoma cells. Conclusion: Hepatoma cell‐secreted exosomal miR‐103 increases vascular permeability and promotes tumor metastasis by targeting multiple endothelial junction proteins, which highlights secreted miR‐103 as a potential therapeutic target and a predictive marker for HCC metastasis. (Hepatology 2018).
Plant laccase (LAC) enzymes belong to the blue copper oxidase family and polymerize monolignols into lignin. Recent studies have established the involvement of microRNAs in this process; however, ...physiological functions and regulation of plant laccases remain poorly understood. Here, we show that a laccase gene, LAC4, regulated by a microRNA, miR397b, controls both lignin biosynthesis and seed yield in Arabidopsis. In transgenic plants, overexpression of miR397b (OXmiR397b) reduced lignin deposition. The secondary wall thickness of vessels and the fibres was reduced in the OXmiR397b line, and both syringyl and guaiacyl subunits are decreased, leading to weakening of vascular tissues. In contrast, overexpression of miR397b‐resistant laccase mRNA results in an opposite phenotype. Plants overexpressing miR397b develop more than two inflorescence shoots and have an increased silique number and silique length, resulting in higher seed numbers. In addition, enlarged seeds and more seeds are formed in these miR397b overexpression plants. The study suggests that miR397‐mediated development via regulating laccase genes might be a common mechanism in flowering plants and that the modulation of laccase by miR397 may be potential for engineering plant biomass production with less lignin.
Many-body entanglement is often created through the system evolution, aided by nonlinear interactions between the constituting particles. These very dynamics, however, can also lead to fluctuations ...and degradation of the entanglement if the interactions cannot be controlled. Here, we demonstrate near-deterministic generation of an entangled twin-Fock condensate of ~11,000 atoms by driving a rubidium-87 Bose-Einstein condensate undergoing spin mixing through two consecutive quantum phase transitions (QPTs). We directly observe number squeezing of 10.7 ± 0.6 decibels and normalized collective spin length of 0.99 ± 0.01. Together, these observations allow us to infer an entanglement-enhanced phase sensitivity of ~6 decibels beyond the standard quantum limit and an entanglement breadth of ~910 atoms. Our work highlights the power of generating large-scale useful entanglement by taking advantage of the different entanglement landscapes separated by QPTs.
This paper first deconstructs the core of the college English precision education model, combines relevant theoretical knowledge, and constructs a college English precision education model based on ...artificial intelligence. Secondly, the convolutional neural network technology is integrated into the joint probability matrix decomposition model, and the resource recommendation list is generated through the cognitive ability level of students and their individualized needs so as to realize the precise, intelligent recommendation of English education resources. Finally, the performance of the recommendation for teaching English educational resources and the practical effect of the educational model are explored through comparative experiments. The results show that the precision rate and recall rate of the recommendation with a test set of 10% are 0.871 and 0.866, respectively, and the F1 value is 0.88. After the teaching practice, students’ listening ability improved by 0.132, expression ability improved by 0.13, reading ability improved by 0.132, writing ability improved by 0.130, and translation ability improved by 0.128. Based on the paper, the educational model has a positive impact on improving the level of English education in colleges and universities.
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