High Resistance Research Articles

Effects of Sn on the microstructural evolution, mechanical properties and biodegradability of Zn alloys prepared by spark plasma sintering for bone repair

Zn with moderate biodegradation rate and favorable biocompatibility is emerging as promising bone implants. However, inadequate mechanical strength of Zn impedes its widespread clinical use. In this study, a novel high strength Zn-Al alloy was developed by combining micro-alloying Sn and spark plasma sintering. The fine grain structure generated the large grain boundary area, which exhibited high resistance mechanical loading. Meanwhile, the Zn-Sn eutectic could hinder dislocation motion and caused strengthening. As a result, the ultimate compressive strength was greatly increased by 103.8 %, from 121.06±1 MPa for Zn alloy to 246.80±5.29 MPa for Zn-Al-Sn alloy, and the hardness was greatly increased by 69.7 %. Furthermore, the cytocompatibility assessment also indicated that the Zn-Al-Sn alloy exhibited favorable biocompatibility with BMSCs. This study showed that the newly developed Zn-Al-Sn alloy had great potential to be next-generation bone-implants.

Conduction mechanisms analysis of ZrO2-based electrochemical metallization RRAM in different RESET modes

Resistive random access memory (RRAM) based on electrochemical metallization (ECM) is a promising candidate for future nonvolatile memory applications. This paper discusses the resistive switching (RS) behavior and conduction mechanism in the ZrO2-based ECM nonvolatile memory devices. Whether Cu or Ni is used as the top electrode, two different types of I-V curves are found in the same device, representing different RESET modes. The I–V fitting analysis suggests that one RRAM cell can follow two significantly different conduction mechanisms under two types of RESET modes. Under sudden rupture mode, conduction at the high resistance state (HRS) is dominated by a space-charge-limited conduction (SCLC). In contrast, under slow dissolution mode, the devices at HRS tend to show an Ohmic conduction mechanism. These phenomena can be explained by a physical model based mainly on Joule heat or electric field, which is related to the degree of dissolution and rupture of multiple conductive filaments (CFs). Furthermore, the electrical field simulation results based on the solid electrolyte theory by MATLAB further demonstrate the coexistence of two conduction mechanisms in Cu (or Ni)/ZrO2/Pt devices HRS. This paper provides a direction for better understanding the conversion mechanism of ECM RRAM, which is of great significance for the further development of RRAM.

State of the vaginal biocenosis depending on the species diversity of lactobacilli

Bacterial vaginosis is one of the most common reproductive health problems in women. Lactobacillus spp. play a leading role in the vaginal biocenosis and provide local antimicrobial defense, but not all species are equally capable of protecting the vaginal ecosystem from pathogens. Diagnostic methods in practical healthcare do not allow identification of Lactobacillus spp. species, which limits the ability to comprehensively assess the status of the vaginal biocenosis. We conducted a study in which we compared microscopy data of the examined smear with the detection of Lactobacillus spp. and other microorganisms. The aim of the study was to evaluate the species composition of Lactobacillus spp. from the vagina depending on morphologic characteristics and composition of associated flora. The study included 64 conditionally healthy women of reproductive age from 18 to 35 years old. The study of species composition of the vaginal biocenosis and typing of lactobacilli was carried out by real-time PCR methods. The obtained results were processed using generally accepted methods of descriptive and ordinal statistics. During the study, it was found that the vaginal biocenosis was dominated by species of Lactobacillus spp. L. crispatus, L. vaginalis, L. iners and L. jensenii. L. johnsonii was rarely found, and L. acidophilus was not detected. Typing results showed that the vagina was more frequently colonized by more than one species of Lactobacillus spp. while a single species of Lactobacillus spp. was detected less frequently. A correlation was found between Lactobacillus spp. species and bacilli thickness. If thick bacilli are detected in gynecological smear microscopy, they belong to the species L. crispatus, which has high colonization resistance and is a factor in the stability of the vaginal biocenosis. If smear microscopy reveals thin bacilli, then these are species of L. iners and L. jensenii. These representatives of Lactobacillus spp. are not directly related to the dysbiotic state of the vagina, but may indicate the possible development of dysbiosis in the future.

Genome-wide association studies on resistance to powdery mildew in cultivated emmer wheat.

Powdery mildew, caused by the fungal pathogen Blumeria graminis (DC.) E. O. Speer f. sp. tritici Em. Marchal (Bgt), is a constant threat to global wheat (Triticum aestivum L.) production. Although ∼100 powdery mildew (Pm) resistance genes and alleles have been identified in wheat and its relatives, more is needed to minimize Bgt's fast evolving virulence. In tetraploid wheat (Triticum turgidum L.), wild emmer wheat [T. turgidum ssp. dicoccoides (Körn. ex Asch. & Graebn.) Thell.] accessions from Israel have contributed many Pm resistance genes. However, the diverse genetic reservoirs of cultivated emmer wheat [T. turgidum ssp. dicoccum (Schrank ex Schübl.) Thell.] have not been fully exploited. In the present study, we evaluated a diverse panel of 174 cultivated emmer accessions for their reaction to Bgt isolate OKS(14)-B-3-1 and found that 66% of accessions, particularly those of Ethiopian (30.5%) and Indian (6.3%) origins, exhibited high resistance. To determine the genetic basis of Bgt resistance in the panel, genome-wide association studies were performed using 46,383 single nucleotide polymorphisms (SNPs) from genotype-by-sequencing and 4331 SNPs from the 9K SNP Infinium array. Twenty-five significant SNP markers were identified to be associated with Bgt resistance, of which 21 SNPs are likely novel loci, whereas four possibly represent emmer derived Pm4a, Pm5a, PmG16, and Pm64. Most novel loci exhibited minor effects, whereas three novel loci on chromosome arms 2AS, 3BS, and 5AL had major effect on the phenotypic variance. This study demonstrates cultivated emmer as a rich source of powdery mildew resistance, and the resistant accessions and novel loci found herein can be utilized in wheat breeding programs to enhance Bgt resistance in wheat.

Hydrogel-based hybrid membrane enhances in vitro ophthalmic drug evaluation in the OphthalMimic device

Envisaging to improve the evaluation of ophthalmic drug products while minimizing the need for animal testing, our group developed the OphthalMimic device, a 3D-printed device that incorporates an artificial lacrimal flow, a cul-de-sac area, a moving eyelid, and a surface that interacts effectively with ophthalmic formulations, thereby providing a close representation of human ocular conditions. An important application of such a device would be its use as a platform for dissolution/release tests that closely mimic in vivo conditions. However, the surface that artificially simulates the cornea should have a higher resistance (10 min) than the previously described polymeric films (5 min). For this key assay upgrade, we describe the process of obtaining and thoroughly characterizing a hydrogel-based hybrid membrane to be used as a platform base to simulate the cornea artificially. Also, the OphthalMimic device suffered design improvements to fit the new membrane and incorporate the moving eyelid. The results confirmed the successful synthesis of the hydrogel components. The membrane’s water content (86.25 ± 0.35 %) closely mirrored the human cornea (72 to 85 %). Furthermore, morphological analysis supported the membrane’s comparability to the natural cornea. Finally, the performance of different formulations was analysed, demonstrating that the device could differentiate their drainage profile through the viscosity of PLX 14 (79 ± 5 %), PLX 16 (72 ± 4 %), and PLX 20 (57 ± 14 %), and mucoadhesion of PLXCS0.5 (69 ± 1 %), PLX16CS1.0 (65 ± 3 %), PLX16CS1.25 (67 ± 3 %), and the solution (97 ± 8 %). In conclusion, using the hydrogel-based hybrid membrane in the OphthalMimic device represents a significant advancement in the field of ophthalmic drug evaluation, providing a valuable platform for dissolution/release tests. Such a platform aligns with the ethical mandate to reduce animal testing and promises to accelerate the development of safer and more effective ophthalmic drugs.

Matched Electron Transport Materials Enabling Efficient and Stable Perovskite Quantum Dot-based Light-Emitting Diodes.

Here, we report 2,4,6-Tris(3'-(pyridine-3-yl) biphenyl-3-yl)-1,3,5-triazine (TmPPPyTz, 3P) with strong electron-withdrawing moieties of pyridine and triazine to modulate the performance of P-QLEDs. Compared with commonly used 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non-radiative recombination caused by the·Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole-blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of·3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P-QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2%·and an operational lifetime T50·of 3220 hours at an initial luminance of 100 cd m-2, which is 151% and about 11-fold improvement compared to control devices (EQE = 20%, T50 = 297 hours), respectively. These results provide a new concept for constructing the efficient and stable P-QLEDs from the perspective of selective ETM.

Investigation of the nanostructure and nanomechanical properties of the interphase in carbon fiber reinforced polyamide-6 composite

Carbon fiber reinforced polyamide-6 (CF/PA-6) composites have been widely applied in automobile, aerospace, and biomedical industries for their high mechanical properties, high thermal resistance and recyclability. On the purpose of finding ways to improve the interfacial properties, the investigation of the nanostructure and nanomechanical properties of the interphase in CF/PA-6 composites were essential. In this study, MD simulation was carried out to show the interfacial formation and nanostructure of the CF/PA-6 composite model directly at the atomic level and compute the radial distribution function, interfacial energy, total energy. Then the nanomechanical properties of the CF/PA-6 composite, such as interfacial thickness, interfacial modules, interfacial adhesion, were investigated by AFM PF-QNM model. The changes of the radical distribution function and energies over the MD simulation time indicated that the PA-6 chains adsorbed and then regularly folded on the CF surface, displaying the interfacial crystallization of the CF/PA-6 composite model. What stood out in the AFM PF-QNM tests were the abrupt decreasing of the interfacial modulus and the sharp increasing of the interfacial adhesion from those of the carbon fiber to those of the PA-6. The average interfacial thickness of the CF/PA-6 composite was 72 nm. Consistent with the simulation results, the interfacial properties were distinct from the properties of the carbon fiber and PA-6, owning to the adsorption and orderly folding of the PA-6 chains on the CF surface and the changes of the RDF and energies.

Investigation of cross-opsonic effect leads to the discovery of PPIase-domain containing protein vaccine candidate to prevent infections by Gram-positive ESKAPE pathogens

BackgroundEnterococcus faecium and Staphylococcus aureus are the Gram-positive pathogens of the ESKAPE group, known to represent a great threat to human health due to their high virulence and multiple resistances to antibiotics. Combined, enterococci and S. aureus account for 26% of healthcare-associated infections and are the most common organisms responsible for blood stream infections. We previously showed that the peptidyl-prolyl cis/trans isomerase (PPIase) PpiC of E. faecium elicits the production of specific, opsonic, and protective antibodies that are effective against several strains of E. faecium and E. faecalis. Due to the ubiquitous characteristics of PPIases and their essential function within Gram-positive cells, we hypothesized a potential cross-reactive effect of anti-PpiC antibodies.ResultsOpsonophagocytic assays combined with bioinformatics led to the identification of the foldase protein PrsA as a new potential vaccine antigen in S. aureus. We show that PrsA is a stable dimeric protein able to elicit opsonic antibodies against the S. aureus strain MW2, as well as cross-binding and cross-opsonic in several S. aureus, E. faecium and E. faecalis strains.ConclusionsGiven the multiple antibiotic resistances S. aureus and enterococci present, finding preventive strategies is essential to fight those two nosocomial pathogens. The study shows the potential of PrsA as an antigen to use in vaccine formulation against the two dangerous Gram-positive ESKAPE bacteria. Our findings support the idea that PPIases should be further investigated as vaccine targets in the frame of pan-vaccinomics strategy.

Microbiota diversity and anti-Pseudogymnoascus destructans bacteria isolated from Myotis pilosus skin during late hibernation.

Symbiotic microorganisms that reside on the host skin serve as the primary defense against pathogens in vertebrates. Specifically, the skin microbiome of bats may play a crucial role in providing resistance against Pseudogymnoascus destructans (Pd), the pathogen causing white-nose syndrome. However, the epidermis symbiotic microbiome and its specific role in resisting Pd in highly resistant bats in Asia are still not well understood. In this study, we collected and characterized skin microbiota samples of 19 Myotis pilosus in China and explored the differences between Pd-positive and negative individuals. We identified inhibitory effects of these bacteria through cultivation methods. Our results revealed that the Simpson diversity index of the skin microbiota for positive individuals was significantly lower than that of negative individuals, and the relative abundance of Pseudomonas was significantly higher in positive bats. Regardless of whether individuals were positive or negative for Pd, the relative abundance of potentially antifungal genera in skin microbiota was high. Moreover, we successfully isolated 165 microbes from bat skin and 41 isolates from positive individuals able to inhibit Pd growth compared to only 12 isolates from negative individuals. A total of 10 genera of Pd-inhibiting bacteria were screened, among which the genera Algoriella, Glutamicibacter, and Psychrobacter were newly discovered as Pd-inhibiting genera. These Pd-inhibiting bacteria metabolized a variety of volatile compounds, including dimethyl trisulfide, dimethyl disulfide, propylene sulfide, 2-undecanone, and 2-nonanone, which were able to completely inhibit Pd growth at low concentrations.IMPORTANCERecently, white-nose syndrome has caused the deaths of millions of hibernating bats, even threatening some with regional extinction. Bats in China with high resistance to Pseudogymnoascus destructans can provide a powerful reference for studying the management of white-nose syndrome and understanding the bats against the pathogen's intrinsic mechanisms. This study sheds light on the crucial role of host symbiotic skin microorganisms in resistance to pathogenic fungi and highlights the potential for harnessing natural defense mechanisms for the prevention and treatment of white-nose syndrome. In addition, this may also provide promising candidates for the development of bioinsecticides and fungicides that offer new avenues for addressing fungal diseases in wildlife and agricultural environments.

Hastelloy C276/AISI SS304 dissimilar metal welding: A comparative review of the effective application of laser and Micro-GTAW

Hastelloy C276, known for its high temperature strength and corrosion resistance, is essential in the manufacture of medical devices and aerospace components. This study developed a micro-controlled GTA welding technology capable of precisely welding 0.4 mm thick dissimilar metals, Hastelloy C276 and SS304. This technology utilizes advanced digital signal processing (DSP) to control the arc time with precision up to 1/100 of a second and improves the welding quality through spot stitch and cold-welding functions. Moreover, the use of 300A inverter-type GTA welding equipment and 2 kW fiber laser welding equipment in this study improved the precision of the welding process. The effectiveness of this technology has been validated through macro-inspections and heat-affected zone (HAZ) analysis. The new welding technique demonstrates the potential to overcome existing welding limitations on thin Hastelloy C276 plates by integrating digital signal processing and rapid response control mechanisms.

Optimization of turbidity removal and floc formation for ballasted flocculation using magnetite-based agents by response surface methodology

In this study, a static mixer was used as an alternative to the existing flash mixing method for ballasted flocculation to assess the turbidity removal and ballasted floc formation characteristics. Synthetic magnetite exhibits excellent properties, such as high specific gravity, hydrophobicity, and wear resistance, making it a suitable ballast agent (BA). The experimental design was optimized using the response surface methodology. To evaluate turbidity removal, a model based on polyaluminum chloride dosage, BA surface charge, and pH was developed. To assess the ballasted floc characteristics, the BA dosage, BA size, and G value of the static mixer were used. During ballasted flocculation, the impact of the zeta potential of the BA was minimal. Consequently, bonding primarily resulted from the viscosity of the floc caused by physical collisions rather than electrostatic forces stemming from the BA charge. The findings of this study demonstrated promising outcomes, including potential energy savings and process streamlining, by identifying crucial design elements for implementing a static mixer in the ballasted flocculation process.

Novel coal-based carbon encapsulating Co-N-C derived from ZIF-67 composite as an efficient chainmail electrocatalyst for zinc-air batteries

Energy shortages and the global climate crisis have led researchers to develop renewable clean energy sources. Zinc-air batteries have attracted much attention due to their high theoretical energy density, safety, and conversion efficiency. However, the cathodic oxygen reduction reaction (ORR) exhibits slow reaction kinetics and high reaction energy barriers, which require catalysts with high activity, selectivity, and stability to improve the reaction rate. Chainmail catalysts have attracted attention in the field of energy conversion and storage due to their structural stability. In this paper, coal-based carbon encapsulating Co-N-C chainmail electrocatalysts are designed and constructed, which can effectively reduce the thermal crumpling phenomenon of the framework structure, enhance the defect content and provide active sites for ORR. The results show that G/Co-N-C-0.025 exhibits a higher half-wave potential than that of Pt/C, with a high ultimate current density of 4.6 mA cm−2, good cycling stability, and high methanol resistance. A primary zinc-air battery is assembled, with an open-circuit voltage of 1.417 V and a maximum power density of 82 mW cm−2. The specific capacity is 789.2 mAh g−1 at a current of 20 mA cm−2. This work provides new ideas for the design and application of high-performance chainmail electrocatalysts.

Study on the effect of heat treatment on the structure, mechanical and electrical properties of alumina fiber insulation

In this paper, the heat treatment of alumina fiber was studied. The infiltration agent on the fiber surface was removed after heat treatment at 450 °C for 6 h. TG-DSC, scanning electron microscope, x-ray diffraction, Fourier infrared spectrometer, energy dispersive spectrometer, and patterning were used to analyze the thermal weight loss, fiber surface morphology, crystal structure, and composition of alumina fibers. The results show that the aluminum oxide fiber has excellent temperature resistance and does not undergo crystal phase transformation during thermal weight loss. After heat treatment, the fiber surface infiltration agent ablates and dissolves from the fiber surface, and the internal crystal structure of the fiber remains stable. The tensile testing machine was utilized to test the breaking strength of alumina fiber. The fiber still maintained high strength after heat treatment, and the retention rate of breaking strength was greater than 74%. ZC-90G high insulation resistance measuring instrument and WDY-Ⅱ automatic voltage tester were utilized to analyze the insulation resistivity and breakdown strength of alumina fiber before and after heat treatment. The results show that heat treatment can effectively improve the insulation performance and breakdown strength of alumina fiber.

The Improvement in High-Temperature Oxidation Resistance of Ni0.25Co0.25Cr0.22Mo0.14Re0.14 High Entropy Alloy via Industrial Chemical Vapor Aluminizing Process

The effects of the protective coating (NiAl coating) on the high temperature isothermal oxidation resistance of Ni0.25Co0.25Cr0.22Mo0.14Re0.14 high entropy alloy (HEA) was discussed in this work. A nickel aluminide (NiAl) coating was obtained on the Ni0.25Co0.25Cr0.22Mo0.14Re0.14 HEA via the industrial chemical vapor aluminizing (CVA) process. Isothermal oxidation tests were applied to NiAl-coated and uncoated samples in ambient laboratory air for durations of up to 200 hours at 1050°C to investigate the effects of the NiAl coating on high-temperature isothermal oxidation resistance of Ni0.25Co0.25Cr0.22Mo0.14Re0.14 HEA. The results revealed that a protective and slowly growing α-Al2O3 oxide layer formed on the surface of the NiAl-coated HEA samples and remained stable even after 200 hours of isothermal oxidation. For uncoated HEA samples, not only Cr2O3 but also non-protective spinel oxides (CoCr2O4 and NiCr2O4) were detected on the surface. Weight gain was observed in the NiAl-coated HEA samples due to the formation of a protective and slowly growing α-Al2O3 oxide layer on the NiAl coating. In contrast, the uncoated HEA samples experienced weight loss even after 6 hours of isothermal oxidation, as Cr2O3 lost its stability at 1050°C and non-protective spinel oxides formed. Therefore, it has been determined that the NiAl coating significantly enhance the isothermal oxidation resistance of the Ni0.25Co0.25Cr0.22Mo0.14Re0.14 HEA. The α-Al2O3 oxide layer has prevented severe oxidation of NiAl-coated samples due to its stability at 1050°C over 200 hours and its slow growth rate.

Nuclear fusion and nuclear fusion materials

This paper introduces the basic principle of nuclear fusion and the development status of tokamak device, which leads to the core of this paper-nuclear fusion materials. The reason why this paper studies nuclear fusion materials is that up to now, nuclear fusion materials are one of the key difficulties in realizing controlled nuclear fusion. In this paper, the introduction of nuclear fusion materials is mainly the classification of nuclear fusion materials, such as structural materials, first wall materials, etc., and the main materials used in various parts at present. After that, the reasons why nuclear fusion materials are difficult to realize are also introduced. For example, at the point of temperature, the temperature of plasma during nuclear fusion reaction can reach tens of millions of degrees Celsius, while the melting point of tungsten, the known material with the highest melting point, is only over 3,000 degrees Celsius. In addition, the first wall material of nuclear fusion needs high energy resistance.

Mycobacterium bovis BCG reverses deleterious effects of H. pylori components towards gastric barrier cells in vitro

Mycobacterium bovis (M. bovis) Bacillus Calmette-Guerin (M. bovis BCG) strain used in immunotherapy of bladder cancer (onco-BCG) due to its acid tolerance can be a candidate for prevention or reversion of deleterious effects towards gastric cell barrier initiated by gastric pathogen Helicobacter pylori (Hp) with high resistance to commonly used antibiotics. Colonization of gastric mucosa by Hp promotes oxidative stress, apoptosis resulting in the gastric barrier damage. The aim of this study was to examine the ability of onco-BCG bacilli to control the Hp driven gastric damage using the model of Cavia porcellus primary gastric epithelial cells or fibroblasts in vitro. These cells were treated with Hp surface antigens (glycine acid extract-GE or lipopolysaccharide-LPS) alone or with onco-BCG bacilli and evaluated for cell apoptosis and proliferation in conjunction with the level of soluble lipid peroxidation marker (s4HNE). The cell migration was determined by “wound healing assay”, while cytokine response of cells, including interleukin (IL)-33, IL-1Beta, IL-8 and tumor necrosis factor alpha (TNF-α), by the ELISA. The apoptosis of cells pulsed in vitro with Hp surface components present in GE or with LPS was reduced after exposure of cells to mycobacteria. Similarly, the cell regeneration which was diminished by Hp LPS has been improved in response to mycobacteria. This study reveals that vaccine mycobacteria may reduce gastric barrier damage induced by Hp infection.

Is It Safe to Treat Stable Patients with Bacteremic Urinary Tract Infections with High-Resistant-Rate Antibiotics?

Background and Objectives: In most areas of the world, urine bacteria have high resistance rates to third-generation cephalosporins, and it is unclear if it is safe to treat stable patients with bacteremic urinary tract infections (UTI) with those antibiotics. There are recommendations that empiric therapy for a suspected UTI should include only antibiotics with resistance rates less than 10%. Materials and Methods: In this historical observational single center study, we selected 180 stable internal medicine patients hospitalized between January 2019 and December 2021, with identical bacteria isolated from blood and urine cultures. Charts were reviewed to determine if deaths and readmissions up to 30 days after discharge were due to bacterial resistance to initial antibiotic therapy (BRIAT). Results: The patient’s median age was 82 years (1st–3rd quartiles, 73–87 years). A total of 54.4% were female. There were 125 patients treated with ceftriaxone. A total of 38 (30.3%) had BRIAT. Four patients died, but none were because of a delay in appropriate treatment. The median days of hospitalization for all patients was 7 days, and 9 days versus 6 days in those with and without BRIAT. There were no re-hospitalizations for a UTI in patients with BRIAT. Conclusions: We conclude that, despite high resistance rates, empiric ceftriaxone in stable hospitalized patients with a bacteremic UTI is safe. There was no urosepsis-related mortality during the hospitalization or on follow-up. The treatment of all patients with wider-spectrum antibiotics might have decreased the median hospital stay by only one day. The potential effect would be even lower if all patients with a suspected systemic UTI were treated with wide-spectrum antibiotics, because some patients do not have an infection of the urinary tract. A reassessment of the recommendation that empiric therapy for a suspected systemic urinary tract infection should include only wider-spectrum antibiotics is warranted.

Microstructure, corrosion resistance and high temperature oxidation properties of AlCrFeNiCu high-entropy alloy coating by high-speed laser cladding

AlCrFeNiCu high-entropy alloy (HEA) coating was prepared on Zirconium (Zr) rod by high-speed laser cladding (HSLC) technique. The effect of different laser power and scanning speed on the forming quality of the coating was studied. When the specific energy density was in the range of 3.0–3.2 J/mm2, the AlCrFeNiCu HEA coating with good adhesion to the substrate, low dilution rate (small heat affected zone) and no cracks were obtained. The phase structure, microstructure, microhardness, corrosion resistance and high temperature oxidation resistance of the coating were tested and analyzed. The results show that the AlCrFeNiCu HEA coating is composed of 76.9 % BCC phase and 23.1 % FCC phase, in which the BCC phase is mainly composed of disordered BCC phase rich in Cr and Fe elements and ordered B2 phase rich in Al and Ni elements, and the FCC phase is rich in Cu elements. Due to the rapid cooling of HSLC, the coating structure gradually changes from columnar crystal to equiaxial crystal from bottom to top. The hardness of the coating is as high as 805 HV, which may be caused by the solution strengthening effect, lattice distortion effect and slow diffusion effect of HEA. In 3.5 % NaCl solution and 0.1 mol/L KOH solution, the self-corrosion current density of the coating is 4.209 × 10−8 A/cm2 and 4.331 × 10−8 A/cm2, respectively. The passivation film on the surface of the coating is composed of a variety of oxides, and the oxygen vacancy density of the passivation film in the two solutions is 2.552 × 1020 cm−3 and 5.794 × 1020 cm−3, with fewer pitting pits on the surface. The structural integrity of the coating can be maintained after 60 min oxidation at 1200 °C. The oxidation process follows the growth kinetics curve, and the surface oxides mainly comprise FeAl2O4, Al2O3 and Cr2O3. AlCrFeNiCu HEA coating improves the corrosion resistance and high temperature oxidation resistance of the Zr-4 alloy.

Experimental determination of stray currents in parallel operated cells exemplified on alkaline water electrolysis

Avoiding undesired electric field-driven cell-to-cell ion conduction is a common issue in electrochemical bipolar stacks affecting many processes such as alkaline water electrolysis, chlor-alkali electrolysis, and redox flow batteries. In bipolar stack systems, they are known as ionic shunt or stray currents and flow alongside a cell stack through the electrolyte manifolds bypassing the bipolar plates. A similar phenomenon occurs if multiple single cells are operated in parallel with a common electrolyte supply, even though each individual cell is galvanically isolated. If the parallel cells are operated at different voltages, an electrochemical potential gradient is formed across the electrolyte tube manifold, causing stray currents to flow from one cell to the other. It is important to determine and reduce stray currents and its implications to ensure high system efficiency and maximum system lifetime. This work presents a new approach with which stray currents between parallel operated, galvanically isolated electrochemical cells has been determined for the first time. For this purpose, an ionic 4-point measurement was implemented into an experimental setup with two electrolyzer flow cells with a common electrolyte supply using reference electrodes. This approach was used to measure the potential differences ΔE between both electrolyzers exemplarily for alkaline water electrolysis. Combined with the measured ionic resistances of the electrolyte within the polymeric tube manifold, stray currents were accurately determined. The presented results show that the ionic 4-point measurement could be successfully implemented and validated to experimentally determine stray currents between parallelly operated cells. The method presented enabled stray current measurements with high precision in the mA range. Due to the high cell currents and high ionic tube resistance, the stray current is less than 1 % in the introduced electrochemical setup. The demonstrated systematic measurement approach can be easily transferred to other electrochemical systems or processes.

Genetic Analysis of Stripe Rust Resistance in the Chinese Wheat Cultivar Luomai 163.

Stripe or yellow rust (YR) caused by Puccinia striiformis tritici (Pst) is an important foliar disease affecting wheat production globally. Resistant varieties are the most economically and environmentally effective way to manage this disease. The common winter wheat (Triticum aestivum L.) cultivar Luomai 163 exhibited resistance to Pst races CYR32 and CYR33 at the seedling stage and showed a high level adult plant resistance in the field. To understand the genetic basis of YR resistance in this cultivar, 142 F5 recombinant inbred lines (RILs) derived from cross Apav#1 × LM163 and both parents were genotyped with the 16K SNP array and bulked segregant analysis sequencing (BSA-Seq). The analysis detected a major gene, YrLM163, at the seedling stage associated with the 1BL.1RS translocation. Additionally, three genes for resistance at the adult plant stage were detected on chromosome arms 1BL (Lr46/Yr29/Pm39/Sr58), 6BS and 6BL in Luomai 163, whereas Apav#1 contributed resistance at a QTL on 2BL. These QTL explained YR disease severity variations ranging from 6.9 to 54.8%. KASP markers KASP-2BL, KASP-6BS and KASP-6BL for three novel loci QYr.hzau-2BL, QYr.hzau-6BS and QYr.hzau-6BL were developed and validated. QYr.hzau-1BL, QYr.hzau-2BL and QYr.hzau-6BS showed varying degrees of resistance to YR when present individually or in combination based on genotype and phenotype analysis of a panel of 570 wheat accessions. Six RILs combining resistance alleles of all QTL, showing higher resistance to YR in the field than Luomai 163 with disease severities of 10.7-16.0%, are important germplasm resources for breeding programs to develop YR resistant wheat varieties with good agronomic traits.