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•According to the results, we can draw the following conclusions:•Pt nanoparticles are homogenously dispersed on TiO2-CNx supports with different content anatase/rutile phases.•TiO2 ...anatase/rutile phases show a “volcano-type” curve for the HOR electrocatalytic activity over Pt/TiO2-CNx nanocatalysts and Pt/TiO2(25 %R)-CNx exhibits the best HOR electrocatalytic activity and stability.•There is a strong metal-support interaction (SMSI) between Pt nanoparticles and TiO2(25 %R)-CNx support with 25% rutile.•In the range of 1.8–2.8 nm, the HOR electrocatalytic activity increases with decreasing of Pt nanoparticles size.•Pt/TiO2(25 %R)-CNx catalyst is a promising anode catalyst for hydrogen fuel cell.
The multicomponent complex Pt/TiO2-CNx catalysts with different TiO2 anatase/rutile phases synthesized by ethylene glycol reduction were investigated.Herein, FESEM, TEM, BET, XANES, EXAFS, XPS, CV and RDE techniques are adopted to systematically investigate the relationship between composition, structure and performance of catalysts with ultrafine Pt nanoparticles, CNx nanowires and TiO2 co-catalyst. Firstly, we discussed the correlation between HOR electrocatalytic activity and ultrafine Pt nanoparticles in the range of 1.8–2.8 nm. The HOR electrocatalytic activity increases with decreasing of Pt nanoparticles size, showing a “positive” nanoparticle size effect on HOR. Furthermore, the HOR activity of Pt/TiO2-CNx are affected by the content of TiO2 anatase/rutile phases, showing a “volcano-type” curve, and Pt/TiO2(25 %R)-CNx containing 25% rutile has the highest HOR electrocatalytic activity with kinetic current density of 16.801 mA cm−2 and exchange current density of 0.962 mA cm−2. It also revealed a strong metal-support interaction (SMSI) between Pt nanoparticles and TiO2-CNx support resulting from the electrons drift from TiO2-CNx to Pt promotes the HOR electrocatalytic activity of the Pt/TiO2-CNx catalyst. Our results explain to some extent the dependence among Pt nanoparticles, CNx nanowires and TiO2 co-catalyst, as well as the scientific problem between the size of Pt nanoparticles and HOR electrocatalytic activity.
Introducing polarization field of piezoelectric materials is an effective strategy to improve photocatalytic performance. In this study, a new type of BaTiO
3
/CuO heterostructure catalyst was ...designed and synthesized to achieve high piezo-photocatalytic activity through the synergy of heterojunction and piezoelectric effect. The BaTiO
3
/CuO heterostructure shows a significantly enhanced piezo-photocatalytic degradation efficiency of organic pollutants compared with the individual BaTiO
3
nanowires (NWs) and CuO nanoparticles (NPs). Under the co-excitation of ultrasonic vibration and ultraviolet radiation, the optimal degradation reaction rate constant
k
of polarized BaTiO
3
/CuO heterostructure on methyl orange (MO) dye can reach 0.05 min
−
1
, which is 6.1 times of photocatalytic rate and 7 times of piezocatalytic rate. The BaTiO
3
/CuO heterostructure with remarkable piezo-photocatalytic behavior provides a promising strategy for the development of high-efficiency catalysts for wastewater purification, and it also helps understand the coupling mechanism between piezoelectric effect and photocatalysis.
It is highly vital in automotive body, high-speed rail overhead line parts, and water distribution systems to use hot-dip galvanized steel (HDGS) coatings for efficiency and ease of synthesis. ...Various novel coating systems could surpass the technical restrictions of traditional anticorrosion techniques. Because of this, inorganic or organic coating systems must be chosen accurately and suitably. Meanwhile, these coating systems should be evaluated in accordance with their unique material characteristics and synergistic electrochemical parameters. From this view, we summarize an overview of recent developments of anticorrosive coating systems research for HDGS. First, we demonstrate the traditional protective coatings to match the use of HDGS. Likewise, emerging and state-of-the-art protective coatings are summarized. Then, methods for the assessment criteria of traditional and emerging protective coatings are displayed and illustrated through electrochemical analysis. For the conclusion, we make a proposal about the future developments of protective coating systems for HDGS.
RNA interference (RNAi) is a gene-silencing mechanism that plays an important role in gene regulation in a number of eukaryotic organisms. Two core components, Dicer and Argonaute, are central in the ...RNAi machinery. However, the physiological roles of Dicer and Argonaute in the entomopathogenic fungus
have remained unclear. Here, the roles of genes encoding Dicer (
and
) and Argonaute (
and
) proteins in
were investigated. The results showed that the Dicer-like protein MrDCL2 and Argonaute protein MrAGO1 are the major components of the RNAi process occurring in
The Dicer and Argonaute genes were not involved in the regulation of growth and diverse abiotic stress response in
under the tested conditions. Moreover, our results showed that the Dicer and Argonaute gene mutants demonstrated reduced abilities to produce conidia, compared to the wild type (WT) and the gene-rescued mutant. In particular, the conidial yields in the Δ
and Δ
mutants were reduced by 55.8% and 59.3%, respectively, compared with those from the control strains. Subsequently, for the WT and Δ
mutant strains, digital gene expression (DGE) profiling analysis of the stage of mycelium growth and conidiogenesis revealed that modest changes occur in development or metabolism processes, which may explain the reduction in conidiation in the Δ
mutant. In addition, we further applied high-throughput sequencing technology to identify small RNAs (sRNAs) that are differentially expressed in the WT and the Δ
mutant and found that 4 known microRNA-like small RNAs (milRNAs) and 8 novel milRNAs were
dependent in
The identification and characterization of components in RNAi have contributed significantly to our understanding of the mechanism and functions of RNAi in eukaryotes. Here, we found that Dicer and Argonaute genes play an important role in regulating conidiation in
Our study also demonstrates that diverse small RNA pathways exist in
The study provides a theoretical platform for exploration of the functions of Dicer and Argonaute genes involved in RNAi in fungi.
Updated and accurate land cover maps are essential and crucial for sustainable crop production and efficient land management. However, accurate and efficient land cover mapping is still a challenge ...for agricultural regions with complicated landscapes. This study proposed a novel spectral-phenological based land cover classification (SPLC) method to identify the land cover for fragmented agricultural landscapes, with less requirement of ground truth data. The SPLC method integrated a pixel-based support vector machine (SVM) algorithm for cropland and various non-cropland classification, and a phenology-based automatic decision tree algorithm for identification of various crop types. It was then tested and applied in two typical case areas (i.e., Jiyuan in the upstream and Yonglian in the downstream) of Hetao Irrigation District (Hetao) in the upper Yellow River basin (YRB), northwest China. The field survey sampling data and the regional visual interpretation maps were jointly used to evaluate the accuracy of land cover classification. Results indicated that stable phenological rules can be established for crop identification even with complex planting patterns, and the SPLC method performed well in land cover mapping in case areas. Four high-accuracy land cover maps were produced for Jiyuan in 2020 and 2021, Yonglian in 2021, and Hetao in 2021. The overall accuracies (OA) can reach 0.90–0.94 based on evaluation with abundant ground truth data, and land cover maps agreed well with the visual interpretation maps in space. Overall, the case application validated the applicability and efficiency of the SPLC method in land cover mapping for regions with fragmented agricultural landscapes, and also implied the potential use in other similar regions.
In this paper, the mechanoelectrochemical effect on the electrochemical corrosion of 316 L austenitic stainless steel was investigated by theoretical, experimental and simulated methods. The modified ...piecewise formula φa,eq=φa,eq0−ΔPmVmzF−TRzFln(KN0εp+1) for calculating the strain on anode equilibrium potential of austenitic stainless steel was proposed. It is demonstrated that the corrosion current increases from 8.03×10−6A⋅cm−2 to 28.38×10−6A⋅cm−2 within 20% strain, especially within 10%, which is in better agreement with the experimental results. This modification not only made the physical meaning of parameters clearer, simplified the formula, but also made the calculation results more accurate. Moreover, the localized galvanic corrosion caused by non-uniform deformation had been verified by finite element model. The results revealed that the non-uniform strain at the initial stage of strain (εp<0.05) has a greater influence on the corrosion resistance.
Metarhizium anisopliae is one of the most common species of entopathogenic fungi. It has economic and social benefits in many countries where used in agriculture as an important biological control ...agent of insect pests. M. anisopliae can exist as multiple cell types, which suggests that this fungus has a complex way of gene regulation. MicroRNAs (miRNAs) are endogenous small noncoding RNAs. They play a crucial role in the regulation of gene expression and cell function in plants, animals, and in fungi where they were termed miRNA-like RNAs (milRNAs). In this study, we aimed to identify potential milRNAs in M. anisopliae that may regulate the processes of mycelium growth and conidiogenesis (CO). Two small RNA (sRNA) libraries were constructed and submitted to Solexa sequencing. Fifteen milRNAs were identified using deep-sequencing and computational analysis; most of these milRNAs originated from single genes. Database searches revealed that these novel milRNAs had no homologues in other organisms and were, therefore, M. anisopliae-specific. Many of the milRNAs had differential expression profiles for either mycelium growth or CO. The expression of the selected milRNAs was validated by quantitative reverse transcription polymerase chain reaction. Seventy-eight potential target mRNAs for 14 of the milRNAs were identified successfully by computational analysis. These milRNAs may play an important role in the regulation of mycelial growth and conidiation in M. anisopliae. To our knowledge, this study is the first report of milRNA profiles of organisms in the order Hypocreales. This information could be used to study the regulation of genes and their networks in M. anisopliae.
► We identified 15 M. anisopliae-specific milRNAs by highthroughput sequencing. ► Many milRNAs had differential expression profiles in mycelium or conidiogenesis. ► We identified 78 potential target mRNAs for the milRNAs by computational analysis. ► This study is first report of milRNA profiles of organisms in the order Hypocreales.
During last two decades, grain refinement and amorphization are the main way of high-performance material research and development, which already show enormously successful in material science, ...especially super steel engineering. However, the further improvement of material performance by the traditional methods seem to reach its limitation. A novel method is urgent for scientists to break through the limitation. At present, it is difficult to prepare different nanoscale microstructures in the same material system for performance comparison. In this paper, coatings with different microstructure (nanocrystalline, amorphous-nanocrystalline composite and amorphous) have been successfully prepared by electrodeposition method in the same material system (Ni–P alloy). The results show that the amorphous-nanocrystalline Ni–P alloy had higher hardness and better wear resistance. The wear resistance of the amorphous-nanocrystalline Ni–P alloy was 7.4 times of that of the amorphous Ni–P alloy and 3.1 times of that of the nanocrystalline Ni–P alloy. Therefore, the composite of different microphase structures at nanoscale is a new method to obtain high-performance materials.
Two kinds of induction melted Fe-based alloy coatings with chemical compositions (in wt.%) Fe–30.4Cr–3.5B–3.1Si–20.3Ni–8.7Co–3.6Mo–2.7Cu (C+) and Fe–44.1Cr–5.6B–4.7Si (M) deposited onto Q235 steel by ...ultrasonic frequency inductive cladding (UFIC) technique have been investigated in terms of microstructures, phase composition, microhardness and corrosion behavior by SEM/EDS, XRD, Vickers microhardness tester and Raman spectroscopy analyses. The results showed that four morphologies of austenite γ-Fe, eutectics γ-Fe/(Cr,Fe)2B, borides (Cr,Fe)2B and precipitations enriched in Mo contained in the C+ coating whilst ferrite α-Fe, borides Cr1.65Fe0.35B0.96 and eutectics α-Fe/Cr1.65Fe0.35B0.96 were identified in the M coating. EDS line analysis of the interdiffusion zone indicated that element Fe decreased from the substrate into the coating while that of Cr and Si was in the reverse due to the dilution of the substrate. The average microhardness value of the M coating was higher than that of the C+ coating, which was ascribed to the higher volume content of borides uniformly dispersed in the matrix. Due to the formation of the protective oxidation layer formed onto the coating, the corrosion resistance of both coatings increased over one order of magnitude compared with the substrate by the immersion and electrochemical tests in a 3.5wt.% NaCl solution.
•Fe-based coatings were deposited onto Q235 steel by UFIC technique.•Compositional gradients of various elements at the bonding area were studied.•High hardness of the coatings was ascribed to the uniformly dispersed borides.•The oxidation film was useful to improve the corrosion resistance of the coatings.
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