Decrease In Diffusion Coefficient Research Articles

Structural evolution dependency on depth-of-discharge in VO2(B) Li-ion battery electrodes

Bronze vanadium oxide, VO2(B), has gained significant interest as electrode for Li-ion mainly due to the ease of preparation and the experimentally obtainable capacities of >325 mAh g−1 with intercalation of >1Li. In this work, we investigate for the first time the effects of intercalating >0.5Li on the structural phase evolution. Using operando X-ray diffraction, we find that deep discharge (i.e. inserting >0.7Li), has a dramatic effect on the subsequent charge process by introducing significant solid-solution behavior in the two-phase transition between the Li-rich and Li-poor phases. Rietveld refinement shows that the discharge-charge asymmetry is caused by severe structural deformations in the Li-rich state. Furthermore, we find that deep discharge causes capacity fade. This appears to be linked to the structural deformation causing an irreversible decrease in the Li-ion diffusion coefficients, determined herein by galvanostatic intermittent titrations.

Effect of Catheter and Stenosis on Solute Diffusion in Non-Newtonian Blood Flow through a Catheterized Stenosed Artery

The presence of stenosis at the wall of the artery lead to further cardiovascular diseases such as heart attack, stroke and many more. Treatment of a stenosed artery includes the insertion of a catheter through the artery which affects the blood flow and solute dispersion. This present study focuses on the effect of catheter radius and stenosis height on the blood flow and solute dispersion behavior. The problem is modelled using the Herschel-Bulkley fluid to represent the blood rheology, with catheter and stenosis as the boundary conditions. Analytical solutions in integral form are obtained by solving the momentum equation and Herschel-Bulkley constitutive equation. The integrals are numerically evaluated using the Simpson’s 3/8 rule and Regula-Falsi method to obtain the blood velocity. The obtained velocity is employed into the unsteady convective-diffusion equation and solved using the generalized dispersion model (GDM) to analyse the behaviour of solute diffusion. The influence of catheter radius and stenosis height on the diffusion coefficient and mean concentration of solute are observed. Results show that the diffusion coefficient decreases as the catheter radius and stenosis height increases. A decrease in diffusion coefficient simultaneously increases the solute mean concentration.

A Comprehensive Analysis of Selected Anionic Surfactants Behaviour in Aqueous Systems Containing Metal Ions and Inorganic Acid

The influence of co-ions on the adsorption properties of two surfactants: ABS (dodecylbenzene sulfonic acid) and its sodium salt ABSNa50 in the aqueous systems, has been studied and discussed. On the basis of experimental measurements of equilibrium and dynamic surface tension, a series of parameters were determined, such as critical micelle concentration (CMC), adsorption parameters, diffusion coefficients, and the micellar dissociation constant. It was proved that values of CMC vary according the contents of accompanying metal ions (zinc(II), copper(II), cobalt(II), nickel(II)) and hydrochloric acid in the system under discussion. Moreover, it was found that as the concentration of surfactant in the system increases, the estimated values of the diffusion coefficients decrease. The obtained results indicate the need to analyse the basic surface properties of surfactants in case of their application in the systems containing additional substances.

Age-associated thin hair displays molecular, structural and mechanical characteristic changes

Hair thinning occurs during normal chronological aging in women and in men leading to an increased level of thinner hair shafts alongside original thicker shafts. However, the characteristics of age-associated thin hairs remain largely unknown. Here we analyzed these characteristics by comparing at multiscale thin and thick hairs originated from Caucasian women older than 50 years. We observed that the cortex of thick hair contains many K35(+)/K38(−) keratinocytes that decrease in number with decreasing hair diameter. Accordingly, X-ray diffraction revealed differences supporting that thin and thick hairs are different with regards to the nature of the intermediate filaments making up their cortices. In addition, we observed a direct correlation between hair ellipticity and diameter with thin hairs having an unexpected round shape compared to the elliptic shape of thick hairs. We also observed fewer cuticle layers and a reduced frequency of a medullae in thin hairs. Regarding mechanical properties, thin hairs exhibited a surprising increased rigidity, a decrease of the viscosity and a decrease of the water diffusion coefficient. Hence, aged-associated thin hairs exhibit numerous modifications likely due to changes of hair differentiation program as evidenced by the modulations in the expression of hair keratins and keratin-associated proteins and by the X-ray diffraction specters. Hence, hair thinning with age does not consist simply of the production of a smaller hair. It is rather a more profound process likely relying on the implementation of an “aged hair program” that takes place within the hair follicle.

Kinetic and Thermodynamic Properties of Ytterbium Chloride and Fluoride Complexes in Chloride Melts

An important problem concerning rare earth metals and molten salts is the reprocessing of nuclear fuel, since lanthanides are always present in spent nuclear fuel. According to the technology being developed for pyroelectrochemical processing of nuclear waste spent fuel is converted into molten salts by anodic dissolution, followed by electrochemical extraction of actinides from lanthanides.Thus a knowledge of the electrochemistry and thermodynamics of lanthanide compounds in molten salt systems is very useful for the understanding the recycling of spent nuclear fuel.The electroreduction of YbCl3 in alkali chloride melts (NaCl-KCl, KCl, CsCl) was studied in the temperature range 973-1173 K by different electrochemical methods. The diffusion coefficients (D) for Yb(III) and Yb(II) were determined by linear sweep voltammetry, chronopotentiometry and chronoamperometry methods. Decreasing values of D were obtained when the cation in the second coordination sphere changed from Na to Cs. It was shown that such changes are due to the decreasing of counter polarizing effect of cations with increasing cationic radius.The standard rate constants of charge transfer (k s) for the Yb(III)/Yb(II) redox couple were calculated on the basis of cyclic voltammetry data using Nicholson’s approach. The following row of the standard rate constants of charge transfer has been experimentally determined: k s (KCl) < k s (CsCl) < k s (NaCl-KCl).The formal redox potentials E* Yb(III)/Yb(II were obtained in alkali chlorides melts from the linear sweep voltammetry data. From the values of the formal redox potentials were calculated the Gibbs energies and equilibrium constants for the reaction:YbCl2(sol.) +1/2 Cl2(g.) « YbCl3(sol.) (1)It was determined the increasing of the formal entropy for the reaction (1) in transition from NaCl-KCl to CsCl melt that associated with a greater degree of ordering of the reaction products due to the complex formation.Influence of fluoride ions (NaF) on the electrochemical behavior of the Yb(III)/Yb(II) redox couple in an equimolar NaCl-KCl melt was studied. It was determined а decrease of diffusion coefficients and standard rate constants, as well as a shift of the formal redox potentials to the negative region.

The Application of Cellulose Acetate Membranes for Separation of Fermentation Broths by the Reverse Osmosis: A Feasibility Study.

Recently, there has been a special research focus on the bioconversion of glycerol to 1,3-propanediol (1,3-PD) due to its significance in the chemical industry. However, the treatment and separation of fermentation broths is a great challenge. Currently, the reverse osmosis (RO) process is a reliable state-of-the-art technique for separation of biological solutions. This study (as the first to do so) investigated the feasibility of separation of 1,3-PD broths with the use of cellulose acetate (CA) membrane by the RO process. The experiments were carried out using the installation equipped with the plate module, under the transmembrane pressure (TMP) and temperature of 1 MPa and 298 K, respectively. It was found that the used membrane was suitable for broth separation. Indeed, it was noted that 1,3-PD, as a target product, migrated through the membrane; meanwhile, other broth components were rejected in various degrees. Moreover, it was proven that retention of carboxylic acids tended to increase with increasing molecular weight, according to the following order: succinic acid > lactic acid > acetic acid > formic acid. With regards to ions, retention degree increased with the increase of ionic radius and decrease of diffusion coefficient. Finally, it was demonstrated that the CA membrane is resistant to irreversible fouling, which has a positive effect on the economic viability of the process.

Phase-field model of grain boundary diffusion in nanocrystalline solids: Anisotropic fluctuations, anomalous diffusion, and precipitation

The anisotropic phase-filed model of grain boundary diffusion and precipitation of solute in nanocrystalline solids has been developed. In this model, the Cahn–Hilliard equation is generalized for the anisotropic phase-field diffusion of solute and anisotropic compositional fluctuations. It is found that dynamics of solute concentration profile demonstrates the anomalous diffusion behavior with scaling parameters depending on the mobility ratio and microstructure of a solid solution. It is noteworthy that the increase in source concentration can slow down the concentration front propagation due to uphill diffusion or formation of a new phase. Parameters of grain boundary diffusion control the precipitation dynamics. In particular, a decrease in transverse diffusion coefficient is responsible for longer incubation time, and lower rates of nucleation and nuclei growth in comparison with the case of isotropic solute transport near grain boundaries. Transport properties of boundary and bulk are responsible for the formation of the bimodal size distribution function of second phase particles and specific kinetics of average radius and number density.

Modeling pyramidal silicon nanopores with effective ion transport

While the electrical models of the membrane-based solid-state nanopores have been well established, silicon-based pyramidal nanopores cannot apply these models due to two distinctive features. One is its 35.3° half cone angle, which brings additional resistance to the moving ions inside the nanopore. The other is its rectangular entrance, which makes calculating the access conductance challenging. Here, we proposed and validated an effective transport model (ETM) for silicon-based pyramidal nanopores by introducing effective conductivity. The impact of half cone angle can be described equivalently using a reduced diffusion coefficient (effective diffusion coefficient). Because the decrease of diffusion coefficient results in a smaller conductivity, effective conductivity is used for the calculation of bulk conductance in ETM. In the classical model, intrinsic conductivity is used. We used the top-down fabrication method for generating the pyramidal silicon nanopores to test the proposed model. Compared with the large error (≥25% in most cases) when using the classical model, the error of ETM in predicting conductance is less than 15%. We also found that the ETM is applicable when the ratio of excess ion concentration and bulk ion concentration is smaller than 0.2. At last, it is proved that ETM can estimate the tip size of pyramidal silicon nanopore. We believe the ETM would provide an improved method for evaluating the pyramidal silicon nanopores.

Paradoxical Anxiety Level Reduction in Animal Chronic Stress: A Unique Role of Hippocampus Neurobiology.

A paradoxical reduction in anxiety levels in chronic predator stress paradigm (PS) in Sprague–Dawley rats has recently been shown in previous works. In this paper, we studied the possible neurobiological mechanism of this phenomenon. We segregated PS-exposed Sprague–Dawley rats into the high- and low-anxiety phenotypes. The long-lasting effects of PS on corticosterone levels, blood flow speed in the carotid arteries, diffusion coefficient, and 1H nuclear magnetic resonance spectra in the hippocampus were compared in the high-anxiety and low-anxiety rats. In addition, we evaluated the gene BDNF expression in the hippocampus which is considered to be a main factor of neuroplasticity. We demonstrated that in low-anxiety rats, the corticosterone level was decreased and carotid blood flow speed was increased. Moreover, in the hippocampus of low-anxiety rats compared to the control group and high-anxiety rats, the following changes were observed: (a) a decrease in N-acetyl aspartate levels with a simultaneous increase in phosphoryl ethanol amine levels; (b) an increase in lipid peroxidation levels; (c) a decrease in apparent diffusion coefficient value; (d) an increase in BDNF gene expression. Based on these findings, we proposed that stress-induced anxiety reduction is associated with the elevation of BDNF gene expression directly. Low corticosterone levels and a rise in carotid blood flow speed might facilitate BDNF gene expression. Meanwhile, the decrease in apparent diffusion coefficient value and decrease in N-acetyl aspartate levels, as well as an increase in the lipid peroxidation levels, in the hippocampus possibly reflected destructive changes in the hippocampus. We suggested that in Sprague–Dawley rats, these morphological alterations might be considered as an impetus for further increase in neuroplasticity in the hippocampus.

Quantification of spatial subclonal interactions enhancing the invasive phenotype of pediatric glioma.

SummaryDiffuse midline gliomas (DMGs) are highly aggressive, incurable childhood brain tumors. They present a clinical challenge due to many factors, including heterogeneity and diffuse infiltration, complicating disease management. Recent studies have described the existence of subclonal populations that may co-operate to drive pro-tumorigenic processes such as cellular invasion. However, a precise quantification of subclonal interactions is lacking, a problem that extends to other cancers. In this study, we combine spatial computational modeling of cellular interactions during invasion with co-evolution experiments of clonally disassembled patient-derived DMG cells. We design a Bayesian inference framework to quantify spatial subclonal interactions between molecular and phenotypically distinct lineages with different patterns of invasion. We show how this approach could discriminate genuine interactions, where one clone enhanced the invasive phenotype of another, from those apparently only due to the complex dynamics of spatially restricted growth. This study provides a framework for the quantification of subclonal interactions in DMG.

Studies on the abnormal effect of tensile strain on the MC→M23C6 in-situ transformation in Ni-based superalloy

Experiment and first-principles calculations were utilized to study the effect of tensile strain on the MC→M23C6 in-situ transformation in MC-M23C6 complex carbide as well as its micro-mechanism. The experiment indicates that strain inhibits the transformation. According to the calculations, Cr atoms will occupy M sublattice sites and diffusion through the VM-(VC)6 vacancy clusters in MC. Nevertheless, a single VM mechanism works during the diffusion of Cr atoms across the MC/M23C6 interface. Tensile strain as well as its direction can seriously influence the diffusion behavior of atoms by expanding or compressing the lattice. Generally, tensile strain will facilitate the diffusion of Cr atoms in MC and the flipping of diagonals. However, tensile strain decreases the lattice mismatch at the MC/M23C6 interface. Thus, the activation energy of the diffusion of Cr across the interface increases and the diffusion coefficient decreases. Strain inhibits the transformation mainly by restraining the diffusion of Cr atoms across the MC/M23C6 interface. The demonstrated concept enables a deeper understanding of superalloys and shed light on the rational design of higher property superalloys for various potential applications.

Numerical simulation of polymethyl‐methacrylate supercritical fluid foaming process: Bubble growth dynamics

AbstractControl of cell structure is an important factor of fabricating polymer foam, which is related to technological design and product performance. In this article, a multibubble growth model of polymethyl‐methacrylate (PMMA) is established based on supercritical fluid foaming method and fluid simulation, aiming to analyze and predict the effects of foaming conditions (foaming temperature and foaming pressure) on the cell structures of PMMA foams. The bubble growth process is endothermic, resulting in a drop of temperature in PMMA/CO2 system, a decrease in diffusion coefficient and an increase in surface tension and viscosity, thereby preventing bubble growth. The pressure in the outer cells decreases faster than the pressure in the inner cells, causing the outer cells preferentially grow and deform, and will limit the growth of the inner cells. An empirical formula for the average cell size and foaming conditions is obtained.

Diffusion mechanisms of DNA in agarose gels: NMR studies and Monte Carlo simulations.

We report on the diffusion mechanism of short, single-stranded DNA molecules with up to 100 nucleobases in agarose gels with concentrations of up to 2.0% with the aim to characterize the DNA-agarose interaction. The diffusion coefficients were measured directly, i.e., without any model assumptions, by pulsed field gradient nuclear magnetic resonance (PFG-NMR). We find that the diffusion coefficient decreases, as expected, with an increase in both DNA strand length and gel concentration. In addition, we performed Monte Carlo simulations of particle diffusion in a model network of polymer chains, considering our experimental conditions. Together, the Monte Carlo simulations and the PFG-NMR results show that the decrease in diffusion coefficients in the presence of the agarose gel is due to a temporary adhesion of the DNA molecules to the surface of gel fibers. The average adhesion time to a given gel fiber increases with the length of the DNA strands but is independent of the number of gel fibers. The corresponding magnitude of the binding enthalpies of DNA strands to gel fibers indicates that a mixture of van der Waals interactions and hydrogen bonding contributes to the decreased diffusion of DNA in agarose gels.

Abnormal diffusion behavior and aggregation of oxyethylated alkylphenols in aqueous solutions near their cloud point

We have investigated solutions of oxyethylated alkylphenols (neonols) in a mixture of ordinary and heavy water with equal densities of the neonols and the aqueous mixture. The equal densities allow exclusion of sedimentation effects and study of the evolution of micelles and neonol aggregates in the range from room temperature to above the cloud point. The self-diffusion coefficients of neonols were measured by NMR and the effective hydrodynamic radii of micelles and neonol aggregates were calculated using the Stokes-Einstein relation. An abnormal decrease in neonols diffusion coefficients occurred when the system approached the cloud point, while an abnormal increase in the diffusion coefficients occurred at temperatures above the cloud point. We explained the abnormal temperature behavior of the diffusion coefficients of neonols by changes in the size of the diffusing objects from the spherical and spherocylindrical micelles to dehydrated aggregates and the destruction of micelles by thermal motion and by formation of aggregates with sizes of the order 102 nm at temperatures above the cloud point. Conclusions about the increase in the hydrodynamic radii of the micelles with increasing temperature up to the cloud point and about the formation of dehydrated aggregates above the cloud point are confirmed by the results of DLS studies.

Knudsen diffusion in pore-scale water-bearing shales: modelling and case study

Gas diffusivity in shales is significantly affected by water. However studies on the model of diffusion coefficient for water-bearing shales are very limited. In this work, we proposed a model to calculate the Knudsen gas diffusion coefficient at the presence of water in shale nanopores. This model was used to study the gas diffusivity in a real shale pore structure composed of both organic pores and inorganic pores at different water saturations. The model was also utilized to analyze the sensitivity of the Knudsen diffusion coefficient on a variety of factors. Results indicate that the existence of water drastically reduces the Knudsen diffusion in shales. When water saturation increases from 10% to 50%, gas concentration in inorganic pores rises by 53.7%. This effect can happen both in organic pores and inorganic pores due to pore connectivity. Water in inorganic pores can transport into organic pores and hinders gas diffusion in organic pores. The sensitivity study demonstrates that the increase of temperature, pore radius and porosity can lead to the rise of Knudsen diffusion coefficient. Inversely, the increase of tortuosity induces the decrease of the Knudsen diffusion coefficient. The pore wall roughness also affects the Knudsen diffusion coefficient. The rough wall surface contributes to a lower Knudsen diffusion coefficient compared with the smooth wall surface.

The effect of Cr content on intragranular κ-carbide precipitation in Fe-Mn-Al-(Cr)-C low-density steels: A multiscale investigation

The effect of Cr content on intragranular κ-carbide precipitation behaviors in Fe-Mn-Al-Cr-C low-density steels was investigated by X-ray diffraction (XRD), scanning (SEM) and (high-resolution) scanning transmission electron microscopy ((HR)STEM), atom probe tomography (APT), thermodynamic and first-principles calculations. We found that the volume fraction of κ-carbides in near-rapidly solidified samples was decreased with increasing Cr content. The increased Cr content also significantly slowed down the growth rate of κ-carbides during isothermal aging treatment (600 °C/9 h). Thermodynamic calculations showed that the increased Cr content decreased the precipitation temperature of κ-carbides and narrowed the temperature range of κ-carbide formation. The impurity of Cr atoms in κ-carbide structure increased its interfacial energy and elastic strain energy for nucleation, thereby significantly increasing the critical energy for the κ-carbide formation in γ-austenite. Simultaneously, the results of APT and first-principles calculation indicated that the impurity of Cr atoms in the κ-carbide structure preferred to occupy the Al sites, which increased the formation energy of κ-carbides making the κ-carbide formation difficult. In addition, the increased interfacial energy between the κ-carbides and γ-austenite, the improved solubility of Al and C in the γ-austenite and the decreased diffusion coefficient of C in γ-austenite caused by increasing Cr content resulted in a slower growth rate of the κ-carbides. • Effect of Cr addition on intragranular κ-carbides is investigated at multiscale. • Cr addition suppresses formation and reduces growth of κ-carbides. • Cr impurity prefers to substitute Al site increasing formation energy of κ-carbides. • Interfacial and strain energies between κ-carbides/γ-austenite are increased by Cr. • Cr addition affects solubility and diffusion rates of Al and C in γ-austenite.

Extended Wagner-type models and their application to the prediction of the transition from internal to external oxidation

Recent works have paved the way to theoretical predictions of the conditions governing the transition from internal to external oxidation of metals and alloys: such conditions directly result from Wagner (1959)’s classical analytical model, provided that it is made to incorporate a heuristic decrease of diffusion coefficients upon the fraction of oxides, aimed at representing their “barrier effect” upon diffusion. The aim of this paper is to extend these works by removing some of the very restrictive hypotheses introduced by Wagner (1959). First, the formulation initially limited to small fractions of oxides is extended to arbitrarily large fractions. Even in their modified form, the equations are still solvable entirely analytically, albeit with a change of the predicted value of the “critical” fraction of oxides, above which internal oxidation must give way to external oxidation. The new value is in better agreement than previous ones with the scarce available experimental estimates. Second, the formulation is extended to finite – instead of infinitesimal – values of the solubility product governing local chemical equilibrium between the oxide and the chemical elements dissolved in the metallic matrix. The nonlinear equations of the diffusion/precipitation problem then become much more complex and amenable only to some hybrid analytical/numerical solution. The results, although interesting, raise a number of issues essentially tied to the basic hypothesis made of instantaneous local thermodynamic equilibrium. It is finally shown, using a simplistic, prototype kinetic model of oxide precipitation, that relaxation of this hypothesis should permit to solve at least some of these issues.

Core overshoot constrained by the absence of a solar convective core and some solar-like stars

ABSTRACT Convective-core overshoot mixing is a significant uncertainty in stellar evolution. Because numerical simulations and turbulent convection models predict exponentially decreasing radial rms turbulent velocity, a popular treatment for overshoot mixing is to apply a diffusion process with an exponentially decreasing diffusion coefficient. It is important to investigate the parameters of the diffusion coefficient because they determine the efficiency of the mixing in the overshoot region. In this paper, we have investigated the effects of the core overshoot mixing on the properties of the core in solar models. We have constrained the parameters of the overshoot model by using helioseismic inferences and the observation of the solar 8B neutrino flux. For solar-mass stars, the core overshoot mixing helps to prolong the lifetime of the convective core developed at the zero-age main sequence. If the strength of the mixing is sufficiently high, then the convective core in a solar model could survive until the present solar age, leading to large deviations of the sound speed and density profiles compared with the helioseismic inferences. The 8B neutrino flux also favours a radiative solar core. These observations provide a constraint on the parameters of the exponential diffusion model of the convective overshoot mixing. A limited asteroseismic investigation of 13 Kepler low-mass stars with 1.0 &amp;lt; M/M⊙ &amp;lt; 1.5 shows a mass-dependent range of the overshoot parameter. The overshoot mixing processes for different elements are analysed in detail. It is found that the exponential diffusion overshoot model leads to different effective overshoot mixing lengths for elements with different nuclear equilibrium time-scales.

Molecular Dynamics Simulation and Experimental Studies of the Wettability Behaviors of Shales

The wettability behaviors of nanoscale pores in shales from Longmaxi Formation in the Sichuan Basin of South China, which contain quartz pores, illite pores, and organic matter pores, were investigated using the molecular dynamics simulation and experimental methods, and the organic matter surface was approximated by grafting oxygenated functional groups onto a graphite surface. The distribution characteristics of a water–methane system in organic matter pores were studied. The results indicate that the organic matter pore network and the inorganic pore network in shales show cross-distribution characteristics. The speed of spontaneous imbibition of oil is less than that of water, and the spontaneous imbibition mass of oil increases with increasing the total organic carbon (TOC) contents. The surfaces of illite and quartz mineral are hydrophilic. With the increase in oxygen-containing functional groups, the interaction energy between the organic matter surface and water molecules decreases, resulting in an increase in the wetting contact angle of the organic matter surface. With increasing temperature, the interaction energy between the organic matter surface and water molecules increases, resulting in a decrease in the wetting contact angle. In symmetrical graphite pore models with different C/O ratios, water molecules are symmetrically spread near the oxygen-functionalized graphite wall, and with a decrease in the C/O ratio, the relative concentration of water molecules increases and the diffusion coefficient decreases. In contrast, methane molecules are gathered and distributed in the center of the pore. In an asymmetric graphite pore model with different C/O ratios, water molecules are asymmetrically spread near the oxygen-functionalized graphite wall, whereas methane molecules are concentrated and spread in the pore center. The side with a lower C/O ratio has stronger hydrophilicity and a higher relative concentration of water molecules, whereas the side with a higher C/O ratio has stronger hydrophobicity and a lower relative concentration of water molecules.

The high thermal stability induced by a synergistic effect of ZrC nanoparticles and Re solution in W matrix in hot rolled tungsten alloy

The synergistic effect of ZrC nanoparticle pining and Re solution in W matrix on the thermal stability of tungsten was studied by investigating the evolution of the microstructure, hardness and tensile properties after annealing in a temperature range of 1000–1700 °C. The results of metallography, electron backscatter diffraction pattern and Vickers micro-hardness indicate that the rolled W-1wt%Re-0.5 wt%ZrC alloy has a higher recrystallization temperature (1600 °C–1700 °C) than that of the rolled pure W (1200 °C), W-0.5 wt%ZrC (1300 °C), W-0.5 wt%HfC (1400–1500 °C) and W–K-3wt%Re alloy fabricated by the same technology. The molecular dynamics simulation results indicated that solution Re atoms in W matrix can slow down the self-diffusion of W atoms and form dragging effect to delay the growth of W grain, moreover, the diffusion coefficient decrease with increasing Re content. In addition, the ZrC nanoparticles can pin the grain boundaries and dislocations effectively, preventing the recrystallization. Therefore, synergistic effect of solid solution Re element and dispersed ZrC nanoparticles significantly increase recrystallization temperature.