The existence of alkali metals in flue gases originating from stationary sources can result in catalyst deactivation in the low-temperature selective catalytic reduction (SCR) of nitrogen oxides (NOx). It is widely accepted that alkali metal poisoning causes damage to the acidic sites of catalysts. Therefore, in this study, a series of CoMn catalysts doped with heteropolyacids (HPAs) were prepared using the coprecipitation method. Among these, CoMnHPMo exhibited superior catalytic performance for SCR and over 95

The use of electrocatalytic technology to replace traditional harsh thermocatalysis in the process of biomass utilization has undoubtedly been an effective means to achieve green and sustainable development. The use of the environmentally friendly method of synthesizing furoic acid (FA) from the biomass platform compound furfural (FF) by electrooxidation was investigated. The surface of the Ni–Co oxide electrode with a Ni content of 0.48 (Ni0.48Co0.36O0.16) obtained by a simple electrodeposition method was covered by a layer of flower-like porous structure, while NiO and Co3O4 coexisted. Moreover, the Ni0.48Co0.36O0.16 electrode exhibited 95.4% FA faraday efficiency and 99.6% selectivity with a substrate concentration of 20 mM at 1.0 V vs. Hg/HgO and 50°C. In addition, a mechanism for electrooxidation of FF into FA over a Ni-Co oxide electrode was proposed.

The coexistence of chronic pain and anxiety is a common clinical phenomenon. Here, the role of tachykinin receptor 3 (NK3R) in the lateral habenula (LHb) in trigeminal neuralgia and in pain-associated anxiety was systematically investigated. First, electrophysiological recording showed that bilateral LHb neurons are hyperactive in a mouse model of trigeminal neuralgia made by partial transection of the infraorbital nerve (pT-ION). Chemicogenetic activation of bilateral LHb glutamatergic neurons in naive mice induced orofacial allodynia and anxiety-like behaviors, and pharmacological activation of NK3R in the LHb attenuated allodynia and anxiety-like behaviors induced by pT-ION. Electrophysiological recording showed that pharmacological activation of NK3R suppressed the abnormal excitation of LHb neurons. In parallel, pharmacological inhibition of NK3R induced orofacial allodynia and anxiety-like behavior in naive mice. The electrophysiological recording showed that pharmacological inhibition of NK3R activates LHb neurons. Neurokinin B (NKB) is an endogenous high-affinity ligand of NK3R, which binds NK3R and activates it to perform physiological functions, and further neuron projection tracing showed that the front section of the periaqueductal gray (fPAG) projects NKB-positive nerve fibers to the LHb. Optogenetics combined with electrophysiology recordings characterize the functional connections in this fPAG NKB → LHb pathway. In addition, electrophysiological recording showed that NKB-positive neurons in the fPAG were more active than NKB-negative neurons in pT-ION mice. Finally, inhibition of NKB release from the fPAG reversed the analgesic and anxiolytic effects of LHb Tacr3 overexpression in pT-ION mice, indicating that fPAG NKB → LHb regulates orofacial allodynia and pain-induced anxious behaviors. These findings for NK3R suggest the cellular mechanism behind pT-ION in the LHb and suggest that the fPAG NKB → LHb circuit is involved in pain and anxiety comorbidity. This previously unrecognized pathway might provide a potential approach for relieving the pain and anxiety associated with trigeminal neuralgia by targeting NK3R.

Ni–SiC/BN(h) composite coatings were fabricated by electrodeposition to improve the surface performances of parts manufactured by H13 steel. The effects of SiC and BN(h) concentration on the microstructure and tribological behavior of the composite coatings were investigated. It was found that the cellular bulges on the composite coating caused by a tip discharge were increased with the particles concentration, resulting an increased surface roughness. While the grains in the composite coating were refined until the particles concentration reached 37.5 g/L. These dispersed particles embedded in the composite coating can prevent friction pair from cutting into the coating. And the generated wear debris during friction acted as a secondary solid lubricant was responsible for the reduction of friction coefficient. Ni–SiC/BN(h) composite coating with the compact and uniform microstructure, proper distribution of the particles was obtained at the particles concentration of 37.5 g/L, showing the highest wear resistance. It was characterized by the smallest weight loss and width of wear scar. Worn surface analysis showed that the incorporation of the SiC and BN(h) particles led to the composite coatings changing from a ductile to brittle nature. The wear mechanism was dominated by abrasive wear and oxidation wear.

Ni–SiC–BN composite coatings were electrodeposited on H13 steel in a Watt's bath with SiC and BN particles. The effects of SiC and BN concentration in the bath on the microtructure, microhardness and corrosion resistance of the composite coatings were investigated. The results revealed that the coating grains were refined by adding the concentration of SiC and BN particles. The content of these particles embedded in the composite coating increased until the particles concentration reached 37.5 g/L. Ni– SiC–BN composite coating exhibited the highest microhardness (403.0 ± 21.2 HV 0.2 ) when the particles concentration was 37.5 g/L, which was due to the superior dispersion strengthening, fine grain strengthening, high density dislocation strengthening and the supporting effect of high-hardness particles. The composite coating with the maximum capacitance arc radius and R ct value (2.518×10 5 Ω·cm 2 ) was obtained at 25 g/L, showing the highest corrosion resistance, which was attributed to the compact and uniform microstructure. And these particles that act as a barrier limited the exposed area of Ni matrix to the corrosive electrolyte.

The deformation mechanisms of a novel medium Mn steel (Fe-0.14C-7.8Mn-1.65Al-0.11Zr, wt%) were investigated through mixed multiphase preservation-intercritical annealing route. A heterogeneous duplex microstructure consisting of plate-like and equiaxed austenite and ferrite with multiple morphologies and multiscale and Mn inhomogeneous distribution was obtained after intercritical annealing at 680 degrees C for 10 min. The heterostructured sample exhibited excellent strength-ductility synergy with a yield strength of 1022 MPa, an ultimate tensile strength of 1280 MPa, and a total elongation of 53%. Comparative analysis revealed that heterodeformation-induced (HDI) stress was generated during tensile deformation. This stress was primarily responsible for the superhigh yield strength of the heterostructured sample. In addition, the HDI stress could initially trigger premature martensitic transformation of austenite in the grain or phase boundary region and delay the martensite transformation of untransformed austenite to a large strain range due to the shielding effect of the formed core-shell structure, which comprised an untransformed core austenite and a shell alpha'-martensite. Multiple strengthening and ductility-enhancing mechanisms involving transformation-induced plasticity effect, twin-induced plasticity effect, HDI synergistic hardening, and dislocation strengthening occurred sequentially during deformation, leading to the extraordinary strength-ductility combination of the heterostructured medium Mn steel.

In this paper, the tensile fracture energies of smooth and pre-cracked specimens of a carbide-free bainitic steel at various loading rates were investigated. It is demonstrated that the tensile fracture energy of smooth specimen decreases gradually with increasing the loading rate and this is related to the gradually decreased TRIP effect due to less amount of martensitic transformation at higher loading rates. However, the tensile fracture energy of pre-cracked specimen increases with the increase of loading rate and this is associated with more M and M/A islands concentrated at the crack tip at lower loading rates.

In this study, novel multiple gradient structures with various distributions of austenite/martensite phase, grain sizes, and dislocation densities were fabricated in medium-Mn steel by using torsion treatment, and the corresponding tensile properties and deformation mechanisms were investigated. The results showed that the yield strength and the total elongation of the multiple-gradient-structured samples increased by 27% and 25%, respectively, compared with their homogeneous counterparts. A distinct phase transformation behavior was observed in the present gradient medium-Mn steel. That is, the strain-induced martensitic transformation was promoted in the center during the entire tensile deformation process; however, it was suppressed at the surface during the initial deformation stage and then significantly triggered during the remaining deformation process. Moreover, active strain partitioning at the macroscale and microscale occurred during plastic deformation, which led to a higher hetero-deformation induced (HDI) stress in the multiple-gradient samples. A combination of a strong and persistent transformation-induced plasticity effect, active HDI strengthening and HDI hardening, and dislocation strengthening contributed to the superior strength–ductility synergy of the gradient-structured medium-Mn steel.

To improve the corrosion and wear resistance of the coating, zinc-epoxy powder (EP) composite coatings were prepared by alkaline zincate electrodeposition. The surfactants of sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB), dodecyl dimethyl benzyl ammonium chloride (1227) and polyvinylpyrrolidone (PVP) were used to disperse the EP, respectively. SEM and EDX analysis show that EP is successfully incorporated into the zinc coating. The incorporation of EP reduces the roughness of the Zn coatings. The corrosion resistance of the composite coating prepared by using surfactant is enhanced, which may be due to the adequate wetting contact between EP and zinc and the reduction of defects. The composite coating obtained by using SDS has the lowest root mean square roughness. The grain sizes of all coatings are similar. Electrochemical impedance spectroscopy shows that the composite coating with the strongest corrosion resistance obtained by using SDS, which has the largest coating resistance and charge transfer resistance. The addition of EP reduces the friction coefficient of the Zn coatings. The composite coating obtained by using CTAB has the lowest friction coefficient and wear scar width is reduced.

To improve the corrosion and wear resistance of the coating and reduce the effect of hydrogen penetra-tion on the performance of galvanized steel, Zinc-epoxy powder (EP) composite coatings were prepared by alkaline zincate electrodeposition. The results show that the Zn-6 g/L EP coating has the lowest root mean square roughness of 281.99 A. The incorporation of EP enhances the corrosion resistance of the coating. The Zn-6 g/L EP coating has the largest coating resistance and charge transfer resistance. The incorporation of EP can hinder the hydrogen permeation, which may reduce the hydrogen embrittlement of galvanized steel. Tribological experiment shows that the wear resistance of the composite coating is improved. The friction coefficient and wear scar width of the Zn-12 g/L EP coating is the lowest. (c) 2021 Elsevier B.V. All rights reserved.

Single crystals of organic semiconductors with perfect crystal structure and minimal density of defects can exhibit high mobility and low spin scattering compared with their amorphous or polycrystalline counterparts. Therefore, these materials are promising candidates as the spin transport media to obtain long spin relaxation times and spin diffusion lengths in spintronic devices. However, the investigation of spin injection and transport properties in organic single crystals is hindered by the inability to construct devices such as single-crystalline organic spin valves (OSVs). Herein, thin and large organic single crystals of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) were grown on a liquid substrate and transferred to a target substrate carrying ferromagnetic electrodes to construct single-crystalline OSVs. The magnetoresistance (MR) responses of the single crystals were investigated to study their spin injection and transport properties. MR value as high as 17% was probed with an intermediate layer thickness of 269 nm. More importantly, spin transport was still observed in a single crystal of a thickness up to 457 nm, which was much larger than that of polycrystalline thin film. Our research provides a general methodology for constructing single-crystalline OSVs and paves the way to probe the intrinsic spin transport properties of organic semiconductors based on single crystals.

The microporous nanocrystalline chromium coatings were prepared on the H13 steel by electroplating in self-regulating baths. The effects of electroplating parameters including current density, compositions of baths, bath temperature and plating time on the surface quality, thickness of chromium coating and cathode current efficiency were investigated by an orthogonal experiment. Experimental results indicated that the surface quality, thickness of chromium coating and cathode current efficiency can be improved by adjusting these electroplating parameters. Furthermore, bath temperature has the greatest effect on the surface quality of chromium coating, and the high qualified surfaces were only obtained at higher temperatures of 55 and 65°C. Current density was the most significant factor for the thickness of coating and cathode current efficiency. Chromium coating with high surface quality, thickness and cathode current efficiency was obtained at current density 90 A/dm 2 , CrO 3 250 g/L, K 2 SiF 6 10 g/L, SrSO 4 1 g/L, bath temperature 65°C and plating time 120 min, which is consisting of pure nanocrystalline chromium with a body-centered cubic structure. And the coating exhibits much higher microhardness and corrosion resistance than for H13 steel.

The martensitic stainless steel surfacing layer was deposited on the H13 steel using submerged arc welding (SAW). The effect of the tempering conditions (350 degrees C similar to 650 degrees C for 2 h and 450 degrees C for 0.5 h similar to 4 h) on the microstructure, thermal expansion behavior and corrosion resistance was systematically analyzed. The results indicated that tempering led to the transformation of the residual austenite and coarse martensite in the as-welded sample to the fine tempered martensite and carbides (Fe3C-450 degrees C/0.5 h and M7C3-other conditions). An optimal fusion between the H13 steel and surfacing layer was obtained in all cases, with no appreciable cracks. Relative thermal expansion (Delta L/L-0) and thermal expansion coefficient (CTE) were observed to increase at first due to the reduction in the welding defects, followed by a decrease due to the phase transition and microstructure coarsening on increasing the tempering temperature and duration. The thermal expansion behavior closest to that of the H13 steel was obtained at 450 degrees C for 2 h, along with a better thermal stability and lower cracking sensitivity. Furthermore, the surfacing layer with a high alloy content exhibited much better corrosion resistance than the H13 steel. After tempering at or above 450 degrees C for 2 h, the corrosion resistance of the surfacing layers was noted to be higher than the as-welded sample. The corrosion resistance enhanced further on increasing the tempering temperature and duration, which was dependent on the even phase composition and homogeneous microstructure as well as decreased welding defects and grain boundaries. The maximum R-ct value (1.961 x10(5) Omega . cm(2)) was obtained at 650 degrees C for 2 h, thus, suggesting an optimal corrosion resistance.

The coercivity of the CFO/LSMO/PMN-PT heterostructures decreases ∼50%, making it possible to achieve electric-field-controlled magnetoresistance.

In this paper, the wavelet decomposition of the electrochemical noise was successfully applied to derive the wavelet noise resistance (R-cd), which was further used to assess the corrosion behavior of Q235 mild steel in the simulated corrosion atmosphere (the salt spray test with 0.01 and 0.1 mol/L NaCl). The noise signatures, noise resistance (R-n), SEM, and XRD techniques were used as complementary measurements. The electrochemical noise data were acquired from two identical working electrodes by the zero resistance ammeter (ZRA) mode. The experimental results of the noise signatures and R-n indicated that the corrosion rate increased with the exposure time in the early stages of atmospheric corrosion. The analysis of the surface corrosion morphology and R-n showed a higher corrosion rate at a higher concentration of spraying solution. Also, the values of R-n and R-cd closing to the 2 Hz corroborate well in both simulated corrosion atmospheres. The wavelet noise resistance is an effective method for the analysis of the atmospheric corrosion damage of Q235 steel in the marine environment.

BiFeO3 (BFO)-based heterostructures have been widely studied to develop high-speed, high-density and low-consumption nonvolatile memory. In this study, the resistive switching (RS) behavior in metal/BFO/SrRuO3 (SRO) heterostructures was investigated. The I-V curves of Pt/Fe/BFO/SRO and Pt/BFO/SRO heterostructures demonstrate that the RS behavior in the Pt/Fe/BFO/SRO heterostructures results from the fact that ferroelectric polarization modulated the depletion layer width around the BFO/SRO interface. According to the fitting results of the I-V curves, the conductivity mechanisms are the interface-limited Fowler-Nordheim tunneling mechanism in the negative bias and the space-charge-limited conduction mechanism in the positive bias. Compared with the memory performance in the Pt/BFO/SRO heterostructures, the memory performance in the Pt/Fe/BFO/SRO heterostructures evidently improved. The Fe layer with a work function similar to that of the BFO layer can decrease the barrier height and reduce the accumulation of the injected charges at the top-electrode/BFO interface, which further improves the ferroelectric performance of the BFO layer.

In this work, epitaxial La1–xSrxMnO3 (LSMO) films were fabricated on SrTiO3 substrates at temperatures (Ts) ranging from 550 to 750 °C by RF magnetron sputtering. Significant Ts-dependent structural, magnetic, and magnetotransport properties were observed. The LSMO (Ts = 750 °C) film exhibits the colossal magnetoresistance (CMR) of −47% under the magnetic field (H) of 5 T. In contrast, the LSMO (Ts = 650 °C) film demonstrates a huge magnetoresistance (MR) of −98% (H = 5 T) around the metal-insulator transition temperature and –59% at 5 K. The spin-glass-like behaviors indicate that the defects, particularly the oxygen vacancies, in the epitaxial LSMO (Ts = 650 °C) films destroy the double exchange. The huge MR is related to the defect modulated magnetic structures and spin-dependent magnetotransport properties. Our work helps to understand the physical mechanism of the CMR and provides a way for tuning the magnetotransport properties of the perovskite films.

2D conductive metal-organic frameworks (2D c-MOFs) feature promising applications as chemiresistive sensors, electrode materials, electrocatalysts, and electronic devices. However, exploration of the spin-polarized transport in this emerging materials and development of the relevant spintronics have not yet been implemented. In this work, layer-by-layer assembly was applied to fabricate highly crystalline and oriented thin films of a 2D c-MOF, Cu-3(HHTP)(2), (HHTP: 2,3,6,7,10,11-hexahydroxytriphenylene), with tunable thicknesses on the La0.67Sr0.33MnO3 (LSMO) ferromagnetic electrode. The magnetoresistance (MR) of the LSMO/Cu-3(HHTP)(2)/Co organic spin valves (OSVs) reaches up to 25 % at 10 K. The MR can be retained with good film thickness adaptability varied from 30 to 100 nm and also at high temperatures (up to 200 K). This work demonstrates the first potential applications of 2D c-MOFs in spintronics.

目的 改善H13钢表面纳米晶Cr镀层的微观结构和耐腐蚀性能.方法 利用电沉积技术在H13钢表面制备纳米晶Cr镀层,并通过调整热处理工艺调控Cr镀层的结构和性能.通过扫描电子显微镜(SEM)、原子力显微镜(AFM)和X射线衍射仪(XRD)、维氏显微硬度计和中性盐雾试验(NSS)研究了不同热处理工艺下Cr镀层的表面形貌、粗糙度、相结构、硬度及耐蚀性.结果 采用电沉积技术成功在H13钢表面制备出体心立方结构的纳米晶铬镀层,其晶粒和微裂纹尺寸随着热处理温度(200～600℃)和保温时间(1～2h)的增加而增大.当热处理温度达到400℃时,镀层表面检测到Cr2O3氧化层,并随着热处理温度和保温时间的增加,氧化程度逐渐增大.此外,Cr镀层硬度随着热处理温度和保温时间的增加而逐渐降低.在600℃下保温2h后,镀层硬度为(499.8±9.3)HV0.2,与镀态((749.0±13.2)HV0.2)相比,大约下降了33％.然而,经500℃和600℃热处理的镀层具有最好的耐蚀性能,盐雾试验后,镀层表面未见明显腐蚀缺陷,保护评级为10级.结论 随着热处理温度和保温时间的增加,镀层晶粒变大,表面氧化程度加剧,耐蚀性能显著增强.

Surfacing layers on H13 hot-working die steel for the repair and manufacture of structural components using submerged arc welding (SAW) have been tempered at 350 ℃, 450 ℃, 550 ℃ and 650 ℃ for 2 h. The impact toughness of specimens tempered at 350 ℃ were increased significantly, with their microhardness and wear resistance improved due to a decrease in welding defects and secondary hardening caused by the precipitation of carbide. Tempering at 450 ℃ resulted in refinement of microstructure, with a large amount of tempered martensite being formed that significantly improved the microhardness, wear resistance and impact toughness. However, it was found that these mechanical properties were decreased at 550 ℃ due to grain growth. Formation of large numbers of carbide particles resulted in hard abrasive specimens that were difficult to cut, resulted in an overall increase in wear resistance when the specimens were tempered at 650 ℃.