Low Resistance Research Articles

Adaptation of plantations to drought events in arid and semi-arid regions: Evidence from tree resilience

Increasing drought frequency and severity pose a significant risk to global forest plantations, particularly in arid and semi-arid regions. Developing drought-adaptive plantations is particularly important for vegetation restoration in the context of climate warming. Despite the importance of drought response and adaptation, systematic research on these aspects for major tree species remains limited. Here, we collected 467 tree ring cores from eight paired sites of Robinia pseudoacacia L. (a broad-leaved species) and Pinus tabulaeformis C. (a coniferous species) plantations across a typical semi-arid region of the Loess Plateau (LP) to discern the climate-growth patterns of both species using linear mixed models. We employed hypothesis testing to analyze the differences in tree resilience metrics, including drought resistance and recovery ability, and linear mixed models combined with partial least squares path analysis to clarify the driving factors of tree resilience between R. pseudoacacia and P. tabulaeformis. Our findings demonstrated that Palmer Drought Severity Indices is the key limiting climate factor, without spatial variation, on the growth of R. pseudoacacia and P. tabulaeformis, explaining 47.7 % and 69.8 % of the variables effect percentage, respectively. Compared to P. tabulaeformis, R. pseudoacacia is more limited by atmospheric drought stress and soil moisture, with 11.0 % and 17.9 % of the explained effect percentage, respectively. R. pseudoacacia exhibited lower drought resistance ability, evidenced by a lower resistance (the average value is 0.62) and a higher average growth reduction (0.20) than P. tabulaeformis (0.85 and 0.17, respectively). In contrast, R. pseudoacacia had higher drought recovery ability, evidenced by a higher recovery (the average value is 1.19), a shorter recovery period (1.0), and a faster average recovery rate (0.14), than P. tabulaeformis (1.07, 2.0, and 0.08, respectively). Importantly, all tree resilience metrics for both species exhibited spatial consistency across the LP. Tree characteristics had a stronger effect on drought resistance and recovery ability in R. pseudoacacia than in P. tabulaeformis. Soil properties improved R. pseudoacacia drought resistance ability and reduced its drought recovery ability, but had weaker effects on P. tabulaeformis. Additionally, tree size and age strongly influence tree resilience in R. pseudoacacia through preceding year tree growth of drought events and climate sensitivity. These findings underscore the complementary drought resilience of broad-leaved and coniferous species, emphasizing the necessity for adaptive plantations and diversified tree species plantations as a strategic response to the anticipated increase in drought frequency and severity in arid and semi-arid regions.

The potassium channel subunit KV1.8 (Kcna10) is essential for the distinctive outwardly rectifying conductances of type I and II vestibular hair cells

In amniotes, head motions and tilt are detected by two types of vestibular hair cells (HCs) with strikingly different morphology and physiology. Mature type I HCs express a large and very unusual potassium conductance, gK,L, which activates negative to resting potential, confers very negative resting potentials and low input resistances, and enhances an unusual non-quantal transmission from type I cells onto their calyceal afferent terminals. Following clues pointing to KV1.8 (Kcna10) in the Shaker K channel family as a candidate gK,L subunit, we compared whole-cell voltage-dependent currents from utricular HCs of KV1.8-null mice and littermate controls. We found that KV1.8 is necessary not just for gK,L but also for fast-inactivating and delayed rectifier currents in type II HCs, which activate positive to resting potential. The distinct properties of the three KV1.8-dependent conductances may reflect different mixing with other KV subunits that are reported to be differentially expressed in type I and II HCs. In KV1.8-null HCs of both types, residual outwardly rectifying conductances include KV7 (Knq) channels. Current clamp records show that in both HC types, KV1.8-dependent conductances increase the speed and damping of voltage responses. Features that speed up vestibular receptor potentials and non-quantal afferent transmission may have helped stabilize locomotion as tetrapods moved from water to land.

The potassium channel subunit KV1.8 (Kcna10) is essential for the distinctive outwardly rectifying conductances of type I and II vestibular hair cells.

In amniotes, head motions and tilt are detected by two types of vestibular hair cells (HCs) with strikingly different morphology and physiology. Mature type I HCs express a large and very unusual potassium conductance, gK,L, which activates negative to resting potential, confers very negative resting potentials and low input resistances, and enhances an unusual non-quantal transmission from type I cells onto their calyceal afferent terminals. Following clues pointing to KV1.8 (Kcna10) in the Shaker K channel family as a candidate gK,L subunit, we compared whole-cell voltage-dependent currents from utricular HCs of KV1.8-null mice and littermate controls. We found that KV1.8 is necessary not just for gK,L but also for fast-inactivating and delayed rectifier currents in type II HCs, which activate positive to resting potential. The distinct properties of the three KV1.8-dependent conductances may reflect different mixing with other KV subunits that are reported to be differentially expressed in type I and II HCs. In KV1.8-null HCs of both types, residual outwardly rectifying conductances include KV7 (Knq) channels. Current clamp records show that in both HC types, KV1.8-dependent conductances increase the speed and damping of voltage responses. Features that speed up vestibular receptor potentials and non-quantal afferent transmission may have helped stabilize locomotion as tetrapods moved from water to land.

Comparison of 2 Different Types of Arterial and Biliary Anastomoses While Preserving the Gastroduodenal Artery: A Retrospective Study

ObjectiveHere we investigated 2 different arterial reconstruction procedures with preservation of the gastroduodenal artery (GDA) in orthotopic liver transplantation (OLT). MethodsA retrospective cohort study was conducted. The clinicopathological data of 40 pairs of donors and recipients who underwent OLT from May 2018 to August 2023 were analyzed. The GDA of all recipients was preserved during the hepatic arteries reconstruction, which were divided into 2 groups according to different anastomosis locations, namely the end-to-side group (E-S group, n = 17, Branch-patch between the common hepatic and the gastroduodenal artery) and end-to-end group (E-E group, n = 23, between common hepatic and proper hepatic). ResultsDemographics did not differ between both groups (P > .05). The warm ischemia time (WIT) was numerically longer in the E-S group (403.3 ± 103.3 vs 195.2 ± 35.8 s; P < .001), but the cold ischemia time (CIT) was numerically shorter in the E-S group (279.2 ± 74.7 vs 325.2 ± 15.1 min; P = .023). The time of artery reconstruction and duration of surgery was numerically shorter in the E-S group (21.0 ± 3.6 vs 51.0 ± 9.1 min, P < .001; 326.0 ± 103.4 vs 422.7 ± 24.6 min, P = .001). The E-S group had a lower resistance index (RI) (0.5 ± 0.3 vs 0.6 ± 0.1; P = .049). ConclusionBoth groups showed no differences in artery and biliary complications. GDA preservation meets the anatomical and physiological requirements. E-S is superior to E-E by the time of hepatic artery reconstruction and RI.

Imaging the Mahout structure at the Oman desert with the aid of geophysical observations

Geophysical methods may provide crucial information for the characterization of buried impact structures. In this study, we report and comment on the results of the geophysical survey of an elliptical-shaped structure near Mahout at Oman’s central desert. Geophysical models describe the variation in the physical properties of this structure’s subsurface in terms of density, magnetic susceptibility, and electrical resistivity of the formations buried under the desert sand. For the two former physical properties, a 3D inversion scheme was utilized, while for the latter, the very-low-frequency electromagnetic (VLF-EM) method and 2D inversion were involved for the first time in a similar study. The resultant models are in good agreement for imaging a generally bowl-shaped structure buried under the desert sand with a low resistivity (&amp;lt;40 Ohmm), highly magnetic (magnetic susceptibility 0.03–0.08 SI), and mixed density center (2.2–3.2 g/cm3). The results of the integrated geophysical survey at Mahout enhance the information about the applicability of the specific geophysical techniques at structures buried by sandy formations with less than 1-km diameter, which, currently, mostly comes from large-scale impact craters (&amp;gt;100 km), and confirm that such a multi-geophysical approach can be successful for imaging similar structures.

Rare earth doped CeO2 uniformly enwraps graphite felt as high current density electrode for all vanadium redox flow battery

Although the introduction of metal oxides can solve the problem of poor electrochemical activity of graphite felt electrode, their low conductivity, poor dispersibility, and difficulty in nanocrystallization restrict their application development. Herein, a uniform distributed Gd or Sm doped CeO2 nanoparticle decorated graphite felt electrode is successfully prepared by hydrothermal method. The incorporation of Gd3+ or Sm3+ into the lattice of CeO2 results in the formation of numerous oxygen vacancies, acting not only as reaction sites for redox reactions but also enhancing the charge transfer rate. Compared to CeO2/GF, Ce0.8Gd0.2O2/GF and Ce0.8Sm0.2O2/GF exhibits superior electrochemical activity and lower charge transfer resistance. Correspondingly, the energy efficiency of Ce0.8Gd0.2O2/GF and Ce0.8Sm0.2O2/GF increases 4.5 % and 7.8 % at 160 mA cm−2, respectively. The maximum operating current density of Ce0.8Sm0.2O2/GF is 200 mA cm−2, while Ce0.8Gd0.2O2/GF is 160 mA cm−2. Ce0.8Sm0.2O2/GF achieves an energy efficiency of 69.3 % using a flow-by flow field at 200 mA cm−2. The optimal doping concentration for Sm is 20 %. The Ce0.8Sm0.2O2/GF stably operate for 500 cycles at 100 mA cm−2 and the Ce0.8Sm0.2O2 nanoparticles adhere firmly to the GF without observed detachment. These results demonstrate that Ce0.8Sm0.2O2/GF with high activity and stability is a promising electrode for VRFB.

Molecular characteristics, clonal transmission, and risk factors of Clostridioides difficile among hospitalized patients in a tertiary hospital in Ningbo, China

BackgroundNosocomial transmission of Clostridioides difficile infection (CDI) has been documented in Ningbo, China. However, data on molecular characteristics, clonal transmission, and risk factors of CDI in this region remain limited.MethodsA cross-sectional study enrolled hospitalized patients with diarrhea during September to November 2021. Stool samples from all patients were tested for C. difficile, and isolated strains underwent toxin gene identification, genotyping, and antibiotic susceptibility testing. Whole-genome sequencing and epidemiological variables were analyzed in patients infected with C. difficile strains of the same sequence types (STs) to identify nosocomial transmission and risk factors for CDI.ResultsOf the 907 investigated patients, 115 (12.7%) had microbiologically proven CDI, as their diarrhea was associated with toxigenic C. difficile strains, which comprised 106 A+B+CDT−, 3 A−B+CDT−, and 6 A+B+CDT+. Predominant genotypes (ST2, ST3, ST35, and ST54) exhibited distinct antibiotic resistance patterns. ST54 strains showed higher resistance to erythromycin (100%) but lower resistance to moxifloxacin (18.2%) and gatifloxacin (18.2%) (χ2 = 10.24–16.65, p &amp;lt; 0.05). ST35 strains exhibited higher resistance to ciprofloxacin (66.7%) and tetracycline (33.3%) than other STs (χ2 = 13.30–20.19, p &amp;lt; 0.05). Genomic and epidemiological analysis revealed two nosocomial clonal transmission events caused by 5 ST35 strains (with ≤2 single nucleotide polymorphism differences), elucidating clonal transmission among different floors and buildings within the hospital. Prolonged hospitalization (&amp;gt; 10 days) (odds ratio [95% confidence interval], 1.76 [1.05–2.93]) and penicillin-class antibiotics (1.69 [1.11–2.58]) were risk factors for CDI, with the latter being an independent risk factor (1.57 [1.02–2.42]). For C. difficile ST35 infection, intensive care unit (12.00 [2.77–52.05]) and neurology departments (8.08 [1.46–44.65]) admissions were risk factors, with the latter as an independent risk factor (1.56 [1.01–2.40]).ConclusionMultiple C. difficile genotypes with varied antibiotic resistance patterns circulated in Ningbo, with ST35 causing nosocomial clonal transmission among different floors and buildings within the hospital. These findings and the identified risk factors necessitate enhanced surveillance and infection control in the region.

Customized low heat resistance interfacial structure endowing multifunctional composite with excellent thermal conductivity

Multifunctional polymer-based thermal management composites are essential for the long-term normal service of modern electronic devices. However, multi-position interfacial thermal resistance attributed to the difference in the phase structure significantly limits the full performance of the composite. Herein, based on the molecular structure of a composite formed by boron nitride nanosheets (BNNSs) and aramid nanofibers (ANF), sulfonated ionic liquid (s-IL) was selected by DFT calculation to establish a multiple non-covalent bonding interface structure that comprehensively improves the performance, especially heat transfer. Depending on the functionalization of s-IL, the interface structures of cation-π and OH⋯π constructed between BNNSs and the OH⋯O interaction built between BNNSs and ANF gives the composites a thermal conductivity of up to 23 W/m K−1. In addition, the tensile strength, limiting oxygen index, volume resistivity, and electronic breakdown strength of ∼129 MPa, ∼42 %, ∼2.44 × 1012 Ω cm, and ∼78 kV mm−1 facilitate the excellent multifunctional property of the composite. Non-equilibrium molecular dynamics (NEMD) simulation further revealed that electron–phonon coupling mechanism in the “super-highway” thermally conductive pathways constructed by s-IL enhanced interfacial heat transfer. The customized interface structure design opens a new platform for the development of multifunctional thermal management materials with a low interfacial heat resistance in electronic devices filed.

Evaluating karst features and geological fault leakage risks based on geophysical method in Dongzhuang reservoir area, Shaanxi

Leakage along faults, particularly in karst area faults, is a critical concern that can prevent impounding a reservoir. The Laolong Mountain fault in the Dongzhuang Reservoir Project Area in Shaanxi Province, China, is a large fault that may impede the project. To assess whether concentrated leakage can occur along this fault, we used a comprehensive approach involving footrill exploration, an electromagnetic method, optical imaging techniques, water pressure testing, and large-scale groundwater tracer tests. Footrill exploration results revealed that the karst features predominantly comprise karst cavities with some fissures and karst caves. These formations are typically clustered along fractures with a linear joint density of 0.4–1.5 joints/m. The linear karst rate was 0.39 %, and the karst cavities have small diameters of only a few centimeters and depths not exceeding 15 cm. A geophysical exploration indicated that low resistivity values (approximately 200 Ω·m) on the north side of the fault zone's hanging wall, with the lowest values being approximately 100 Ω·m. The fault's footwall was noted to have higher resistivity (approximately 2000 Ω·m). The rock properties on either side of the fault zone differ considerably. The upper plate of the fault (downstream of the river) has high-resistance carbonate rock formations with a well-preserved structure, whereas the lower plate (upstream of the river) comprises low-resistance sandstone and mudstone formations with notable fragmentation at the fault's surface compression zone. Tracer tests indicated an eastward groundwater flow from Zuantian Ridge toward the Jing River in the west. The results suggest that eastward leakage along the Laolong Mountain fault and its influence zone is unlikely upon reservoir impoundment. The geophysical exploration method in this study integrated and cross-validated the footrill exploration, hydrological test, groundwater tracing, optical imaging, and other methods; it can thus serve as a reference for future research.

Electro-Fenton purification of floodwater with a poly(vinyl alcohol)-treated FeNi3@laser-induced 3D-graphene composite anode from Kraft paper

Electro-Fenton process has been recognized in recent decade as a useful method for removing water contaminants via electrochemical redox reactions at large scale. Laser-induced graphene (LIG) with 3D porous structure is an electrically conductive carbon material, which can be used as a promising electrode for electro-Fenton water purification. This work presented a straightforward synthesis of LIG electrode by direct CO2 laser scribing on the lignocellulose-based Kraft paper. The magnetic FeNi3 nanoparticles were sandwiched by two LIGs as a Fenton catalyst, which were then coated with poly(vinyl alcohol) (PVA) in cross-linking solution. The resulting PVA-treated FeNi3@LIG electrode exhibited outstanding electrochemical stability, low resistance (29 Ω/Sq), high conductivity (1,013 S/m), and fast electrochemical reaction kinetic (80 mV/dec) suitable for electro-Fenton water purification. Compared to PVA-treated LIG electrode, PVA-treated FeNi3@LIG did effectively remove contaminants in floodwater that sampled from flood-ravaged He’nan Province, China. Notably for degrading organic pollutants, the removal efficiencies of chemical oxygen demand, total nitrogen, ammonia nitrogen, total phosphorous were approximately 86 %, 70 %, 77 % and 96 %, respectively. Meanwhile, the heavy metal ions were adsorbed to cathode and reduced into metal form. The metallic selenium and arsenic ions were also removed via adsorption and precipitation. The concentration of sulfate and nitrate in floodwater decreased rapidly from 76 and 9 mg/L to 54 and 0.5 mg/L, respectively. Due to the oxidation stress and cell death during electro-Fenton process, the number of total bacteria was removed by ∼ 73 %, in particular, the fecal coliform was removed completely. The demonstrated lignocellulose LIG electrode is eco-friendly, facile and cheap (∼ 25 USD/m2), which can be made scalable using existing roll-to-roll papermaking line. This work provided new and efficient technology for floodwater treatment.

One-pot synthesis of 2D-Ni-MOF from waste PET plastic in aqueous medium for selective electrooxidation of glycerol, ethanol, and methanol

This study investigates the electrochemical performance and selectivity of a nickel-based metal-organic framework (Ni-MOF) catalyst synthesized from waste PET plastic using a one-pot approach in aqueous media. The Ni-MOF electrode was evaluated for glycerol electrooxidation reaction (GEOR), ethanol electrooxidation reaction (EEOR), and methanol electrooxidation reaction (MEOR). Linear sweep voltammetry (LSV) revealed current densities of 30mA/cm² at 0.5639V for GEOR, 50.07mA/cm² at 0.35V for EEOR, and 45.73mA/cm² at 0.39V for MEOR, indicating superior catalytic activity. Nyquist plots showed lower charge transfer resistance (Rct) values of 11.0 Ω for GEOR, 2.79 Ω for EEOR, and 2.69 Ω for MEOR, confirming efficient electron transfer. Bode impedance plots demonstrated lower impedance for alcohol electrooxidation compared to oxygen evolution reaction (OER). Chronoamperometry (CA) tests indicated excellent stability with 75.72% glycerol conversion for GEOR and selectivities of 94% for glyceric acid, 65.59% for acetic acid in EEOR, and 70.54% for formic acid in MEOR. These results highlight the potential of Ni-MOF derived from recycled PET plastic for sustainable and efficient electrooxidation of C1-C3 alcohols.

Constructing O doped g-C3N4 nanosheets as photocatalysts for photocatalytic water splitting derived hydrogen isotopic water separation

The disposal of tritium-containing wastewater has been an enormous challenge because of its severe hazards to ecological environment. Due to the nearly identical physicochemical properties of hydrogen isotopes, the present disposal methods usually deliver low separation efficiency and high energy-intensive. Herein, photocatalytic water splitting has been firstly carried out to separate hydrogen isotopic water through the hydrogen evolution processes. The O doped graphitic carbon nitride (OGCN) as photocatalyst delivers a competitive separation factor of 4.69 with a gas evolution rate of 6.511 mmol g−1 h−1. The OGCN samples show lager surface area and abundant O dopants after the thermal oxidative etching, thus boosting the diffusion of photogenerated charge carries and delaying the recombination of photogenerated hole-electrons. The separation of hydrogen isotopes is mainly attributed to the kinetic isotope effect and the difference of bond energy between H2O and D2O. The electrochemical impedance spectra imply a lower electrical resistance of H2O than that of D2O, leading to a faster migration rate of charge carriers in H2O solution.

Effect of discharge thermal action in ECDM on electrochemical behaviours of matrix material and its recast layer in glycol-based solution

The interaction between thermal and electrochemical corrosion in the ECDM process remains unclear. This study clarifies the effect of discharge thermal action on electrochemical corrosion. Real-time temperature curves indicate that the solution temperature in the electrochemical corrosion zone increased significantly due to discharge thermal action. The corrosion resistance of the recast layer’s passive film is superior to that of the matrix due to the enrichment of Cr2O3. As the electrolyte temperature rises, the passive film thickens but shows lower polarization resistances and poorer corrosion resistance due to a loose and weak structure. The matrix material and its recast layer dissolved uniformly, resulting in a considerably flat surface in a glycol-based solution, with enhanced levelling efficiency due to discharge thermal action.

Three-dimensional allium flower-like iron-cobalt sulfide nanomaterials for high-performance supercapacitors

Supercapacitors with their improved performance in high energy density and long-term cycling stability have been the growing trend in recent years for fulfilling the demand of efficient energy storage systems. Herein, we report morphology-controlled three-dimensional (3D) Allium flower-like bimetallic iron-cobalt sulfide (3D-FeCoS AF) nanomaterials on nickel foam (NF) electrodes using a single-step electrochemical deposition strategy. The self-standing bimetallic 3D-FeCoS AF nanostructures show good performance towards the supercapacitance applications. The 3D-FeCoS AF nanostructures delivered a specific capacitance of ∼375.7 F g−1 at a current density of 1.0 A/g. The possible electron cloud delocalization among the FeS nanostructures through d-bands leads to the lower charge transport resistance at the 3D-FeCoS AF electrode–electrolyte interfaces and improved conductivity. The 3D-FeCoS AF electrode demonstrated excellent specific capacity and rate performance in a 2.0 M KOH electrolyte. Owing to their enormous electrochemical active surface area (ECSA) and distinctive 3D nanosheet morphology, the present 3D-FeCoS electrode holds great potential for the fabrication of additional transition metal sulfide materials for excellent supercapacitor performances. The findings of this study suggest promising prospects for the utilization of these materials in practical supercapacitance applications.

Enhanced electrocatalytic performance and exceptional durability facilitate the effective degradation of m-dinitrobenzene wastewaters utilizing a novel SS/PbO2-Y2O3-SiC electrode

The intrinsic toxicity of m-dinitrobenzene (m-DNB) to human health and the environment has made dealing with m-DNB pollution a major concern. Herein, a novel hydrophobic anodic electrode SS/PbO2-Y2O3-SiC doped with Y and SiC was constructed via a simple electrodeposition strategy for efficient degradation of m-DNB. With a dense-uniform structure and hydrophobic surface, such SS/PbO2-Y2O3-SiC electrode exhibits obviously lower activation energy (8.17kJmol−1) and charge transfer resistance (1.15 Ω cm2), higher electrochemical active area (46.14 cm2) and stability (359 d), in comparison to SS/PbO2. The m-DNB removal efficiency of the as-prepared SS/PbO2-Y2O3-SiC anode was significantly increased to 96.4% in 180minutes, and the degradation reaction-order was determined to be 0.9559, which was in accordance with the quasi-first-order reaction kinetics. These are the possible degradation pathways of m-DNB under the action of both cathodic and anodic reactions, according to the GC-MS results. The -NO2 group of m-DNB was first reduced to the -NH2 group at the cathode surface, and then the m-phenylenediamine generated at the cathode was sequentially oxidised by the hydroxyl radicals generated from the anodic electrochemical process, resulting in the generation of H2O and CO2 at the anode surface. Additionally, the Assessment Software Tool (TEST) shows that the SS/PbO2-Y2O3-SiC anode can effectively reduce the risk and harm of m-DNB to the overall environment. This study offers novel perspectives on the development of a highly efficient PbO2 electrode for the degradation of m-DNB pollutants.

Dependence of mechanical and surface properties on crystallographic orientation, twin boundaries, and temperature in CoCrFeMn0.3Ni high-entropy alloys

The CoCrFeMnNi high-entropy alloy (HEA) has been widely studied for its mechanical properties and thermal stability, yet its tribological behaviour remains under explored. In this article, we investigate the effects of temperature and twin boundary spacing on the surface nanotribological properties and subsurface damage of CoCrFeMn0.3Ni HEA through molecular dynamics simulations. Among the orientations, [001] exhibits the highest friction coefficient, indicating the greatest restriction to indenter movement. Higher temperatures reduce wear rates, showing good thermal stability, likely due to thermal softening that decreases high-stress regions and the driving force for dislocation nucleation. Monocrystalline HEA shows lower scratch resistance than twinned workpieces. The loading force correlates with twin boundary distance, with twins increasing strength but excessive twins causing softening. Material removal becomes easier in large twinned workpieces. In monocrystalline HEA, plastic deformation is dominated by partial dislocation slip. However, in twinned workpieces, there are not only partial dislocation slips but also dislocation slips parallel to the twin and twin migration. These findings have important implications for HEA design and their applications in extreme conditions.

Comparative Study Between Friction Stir Welding and Tungsten Inert Gas Welding Processes

This study compares the properties of the aluminium alloy welded joints prepared by friction stir welding (FSW) to that of tungsten inert gas (TIG). It concentrated on the microstructure, hardness, corrosion resistance, and wear resistance. It has been found that the joints prepared by FSW have fine microstructure while coarse grains microstructure was obtained for joints produced by TIG welding. Also, the lowest Rockwell hardness measured at the centre of the welding line is 52 for joints prepared by FSW and 46 for ones produced by TIG welding. For corrosion resistance the reslt of tests indicated that the welded joints of the TIG process had higher corrosion resistance, the mass loss after 72 hours is 0.2519 grams from TIG joints and it is about double in the case of FSW joints (0.5263 grams). However, TIG joints have lower wear resistance compared to joints produced by the FSW process. It seems that the grain size of the welded joints, in these two considered welding processes, has a great effect on the investigated properties.

Design and construction of robust nickel-based MOFs for promoting HER catalytic activity

The proposal of the dual-carbon target has attracted widespread attention to explore hydrogen evolution reaction (HER) electrocatalysts to promote the development of clean energy. Here, we propose a strategy to form hierarchically porous electrocatalytic hydrogen evolution catalysts (MOFs I−II) by calcining prefabricated Ni-metal–organic frameworks (MOFs 1 − 2) under N2 atmosphere. Among them, three-dimensional (3D) porous MOFs 1 − 2 have been synthesized by solvothermal method based on scissor-shaped tetracarboxylic acid, named {[Ni2(L)(1,3-bit)(H2O)3](C2H3N)}n (MOF 1) and [Ni4(tib)(L)2(H2O)3(μ2-O)]n (MOF 2). Single crystal diffraction analysis shows that MOF 1 is 3,4,7-connected 3-nodes 3D framework composed of two kinds 2D planes, while MOF 2 is 2,4,7-connected 3-nodes 3D supramolecular structure constructed from 1D chains and 2D planes. As expected, SEM and BET analysis show that calcination produced a unique hierarchical micro-mesoporous structure, while the specific surface area increases by 2.3–3.8 times. The optimized MOF II exposes more active sites, accelerates electrolyte ion diffusion, and has lower electron transfer resistance, allowing it to exhibit excellent electrocatalytic HER performance in an alkaline environment. Notably, MOF II has a Tafel slope of 81 mV·dec−1 (10 mA·cm−2) with a lower overpotential (225 mV). Compared with the pristine MOF 2, the performance of MOF II is significantly improved and it can operate stably for a long time. The possible electrocatalytic HER mechanism has been investigated by density functional theory (DFT). The results are expected to provide inspiration for the rational design and development of stable and efficient MOF-based HER electrocatalysts.

Evaluation of the effect of casting die vibration on the microstructure and mechanical proprties of aluminum alloys : review

Aluminium alloy is one of the most widely used engineering materials due to its properties Relatively lower specific weight and corrosion resistance compared to steel. Moreover, they are They are also relatively easier to machine. Aluminium alloy is found to provide the highest quality Degree of machinability compared to other lightweight metals such as titanium and magnesium Alloy. Various techniques have been used to induce motion during the solidification process of molten metal in the casting mold, such as mechanical vibration, ultrasonic vibration, and electromagnetic vibration. This paper presents a brief review of the above vibration processes and their types, uses, and how they affect the mechanical properties of aluminium alloys

Numerical analysis of thermal and hydraulic characteristics of flow boiling in oblique interconnected microchannel heat sinks

The rising demand for efficient cooling solutions in high-performance electronics underscores the importance of microchannel heat sinks (MCHS) with interconnected channels for thermal management. Despite advancements, limited research has explored the influence of oblique interconnectors on flow distribution and their impact on optimizing thermal and hydraulic performance. This study addressed this gap by numerically investigating the hydrothermal behavior of interconnected MCHS with oblique interconnectors, using HFE-7100 as the working fluid. Six geometric configurations were compared to a baseline parallel microchannel design to determine the optimal interconnector size and orientation. The study employed the Lee mass transfer model and the Volume of Fluid (VOF) approach to capture phase-change dynamics and flow behavior under varying mass fluxes (280.4–1121.6 kg/m2s) and heat fluxes (40–60 W/cm2). The results revealed two distinct flow regimes: suction-induced flows that enhanced thermal performance and disruptive flows that impaired it. One particular design (Case 1) demonstrated superior performance with a ∼26 % higher heat transfer coefficient, ∼23 % lower thermal resistance, and a 12.45 K reduction in wall superheat relative to the baseline, though at the expense of a ∼14 % increase in pressure drop. These findings highlighted the critical role of interconnector orientation in balancing thermal and hydraulic performance, offering a design guideline for future innovations in microchannel heat sinks.