Hydride precipitation in zirconium cladding materials can damage their integrity and durability.Service temperature and material defects have a significant effect on the dynamic growth of hydrides.In this study,we hav...Hydride precipitation in zirconium cladding materials can damage their integrity and durability.Service temperature and material defects have a significant effect on the dynamic growth of hydrides.In this study,we have developed a phasefield model based on the assumption of elastic behaviour within a specific temperature range(613 K-653 K).This model allows us to study the influence of temperature and interfacial effects on the morphology,stress,and average growth rate of zirconium hydride.The results suggest that changes in temperature and interfacial energy influence the length-to-thickness ratio and average growth rate of the hydride morphology.The ultimate determinant of hydride orientation is the loss of interfacial coherency,primarily induced by interfacial dislocation defects and quantifiable by the mismatch degree q.An escalation in interfacial coherency loss leads to a transition of hydride growth from horizontal to vertical,accompanied by the onset of redirection behaviour.Interestingly,redirection occurs at a critical mismatch level,denoted as qc,and remains unaffected by variations in temperature and interfacial energy.However,this redirection leads to an increase in the maximum stress,which may influence the direction of hydride crack propagation.This research highlights the importance of interfacial coherency and provides valuable insights into the morphology and growth kinetics of hydrides in zirconium alloys.展开更多
Zirconium hydride(ZrH_(2)) is an ideal neutron moderator material. However, radiation effect significantly changes its properties, which affect its behavior and the lifespan of the reactor. The threshold energy of dis...Zirconium hydride(ZrH_(2)) is an ideal neutron moderator material. However, radiation effect significantly changes its properties, which affect its behavior and the lifespan of the reactor. The threshold energy of displacement is an important quantity of the number of radiation defects produced, which helps us to predict the evolution of radiation defects in ZrH_(2).Molecular dynamics(MD) and ab initio molecular dynamics(AIMD) are two main methods of calculating the threshold energy of displacement. The MD simulations with empirical potentials often cannot accurately depict the transitional states that lattice atoms must surpass to reach an interstitial state. Additionally, the AIMD method is unable to perform largescale calculation, which poses a computational challenge beyond the simulation range of density functional theory. Machine learning potentials are renowned for their high accuracy and efficiency, making them an increasingly preferred choice for molecular dynamics simulations. In this work, we develop an accurate potential energy model for the ZrH_(2) system by using the deep-potential(DP) method. The DP model has a high degree of agreement with first-principles calculations for the typical defect energy and mechanical properties of the ZrH_(2) system, including the basic bulk properties, formation energy of point defects, as well as diffusion behavior of hydrogen and zirconium. By integrating the DP model with Ziegler–Biersack–Littmark(ZBL) potential, we can predict the threshold energy of displacement of zirconium and hydrogen in ε-ZrH_(2).展开更多
Two-dimensional diagnosis of laser-induced zirconium(Zr)plasma has been experimentally performed using the time-of-flight method by employing Faraday cups in addition to electric and magnetic probes.The characteristic...Two-dimensional diagnosis of laser-induced zirconium(Zr)plasma has been experimentally performed using the time-of-flight method by employing Faraday cups in addition to electric and magnetic probes.The characteristic parameters of laser-induced Zr plasma have been evaluated as a function of different laser irradiances ranging from 4.5 to 11.7 GW cm-2 at different axial positions of 1–4 cm with a fixed radial distance of 2 cm.A well-supporting correlation between the plume parameters and the laser-plasma-produced spontaneous electric and magnetic(E and B)fields was established.The measurements of the characteristic parameters and spontaneously induced fields were observed to have an increasing trend with the increasing laser irradiance.However,when increasing the spatial distance in both the axial and radial directions,the plasma parameters(electron/ion number density,temperature and kinetic energy)did not show either continuously increasing or decreasing trends due to various kinetic and dynamic processes during the spatial evolution of the plume.However,the E and B fields were observed to be always diffusing away from the target.The radial component of electron number densities remained higher than the axial number density component,whereas the axial ion number density at all laser irradiances and axial distances remained higher than the radial ion number density.The higher axial self-generated electric field(SGEF)values than radial SGEF values are correlated with the effective charge-separation mechanism of electrons and ions.The generation of a self-generated magnetic field is observed dominantly in the radial direction at increasing laser irradiance as compared to the axial one due to the deflection of fast-moving electrons and the persistence of two-electron temperature on the radial axis.展开更多
In order to understand the dnve-in target in a D-D type neutron generator,it is essential to study the mechanism of the interaction between hydrogen ion beams and the hydrogenabsorbing metal film.The present research ...In order to understand the dnve-in target in a D-D type neutron generator,it is essential to study the mechanism of the interaction between hydrogen ion beams and the hydrogenabsorbing metal film.The present research concerns the nucleation of hydride within zirconium film implanted with hydrogen ions.Doses of 30 keV hydrogen ions ranging from 4.30×10^（17） to1.43×10^（18） ions cm^（-2） were loaded into the zirconium film through the ion beam implantation technique.Features of the surface morphology and transformation of phase structures were investigated with scanning electron microscopy,atomic force microscopy and x-ray diffraction.Confirmation of the formation of 5 phase zirconium hydride in the implanted samples was first made by x-ray diffraction,and the different stages in the gradual nucleation and growth of zirconium hydride were then observed by atomic force microscope and scanning electron microscopy.展开更多
Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency （RF） msgnetron sputtering at room temperature, The...Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency （RF） msgnetron sputtering at room temperature, The RF power is varied from 75 to 150 W. At first the crystallinity and conductivity of the film are improved and then both of them show deterioration with the increase of the RF power, The lowest resistivity achieved is 2.07 × 10^-3Ωcm at an RF power of 100W with a Hall mobility of 16cm^2V^-1s^-1 and a carrier concentration of 1.95 × 10^20 cm^-3. The films obtained are polycryetalline with a hexagonal structure and a preferred orientation along the c-axis, All the films have a high transmittance of approximately 92% in the visible range. The optical band gap is about 3.33 eV for the films deposited at different RF powers.展开更多
Co/SiO2 and zirconium promoted Co/Zr/SiO2 catalysts were prepared using dielectric-barrier discharge （DBD） plasma instead of the conventional thermal calcination method. Fischer-Tropseh Synthesis （FTS） performance...Co/SiO2 and zirconium promoted Co/Zr/SiO2 catalysts were prepared using dielectric-barrier discharge （DBD） plasma instead of the conventional thermal calcination method. Fischer-Tropseh Synthesis （FTS） performances of the catalyst were evaluated in a fixed bed reactor. The results indicated that the catalyst treated by DBD plasma shows the higher FTS activity and yield of heavy hydrocarbons as compared with that treated by the conventional thermal calcination method. Increase in CO conversion was unnoticeable on the Co/SiO2 catalyst, but significant on the Co/Zr/SiO2 catalyst, both prepared by DBD plasma. On the other hand, heavy hydrocarbon selectivity and chain growth probability （a value） were enhanced on all the catalysts prepared by the DBD plasma. In order to study the effect of the DBD plasma treatment on the FTS performance, the catalysts were characterized by N2-physisorption, H2-temperature programed reduction （H2-TPR）, H2-temperature- programmed desorption （H2-TPD） and oxygen titration, transmission electron microscope （TEM） and X-ray diffraction （XRD）. It was proved that, compared with the traditional calcination method, DBD plasma not only could shorten the precursor decomposition time, but also could achieve better cobalt dispersion, smaller Co304 cluster size and more uniform cobalt distribution. However, cobalt reducibility was hindered to some extent in the Co/SiO2 catalyst prepared by DBD plasma, while the zirconium additive prevented significantly the decrease in cobalt reducibility and increased cobalt dispersion as well as the FTS performance.展开更多
This paper studies the shaped charge jet performance in terms of different liner shapes including conical,bell,hemispherical and bi-conical liners.The critical angles and the relevant flow velocities for the zir-coniu...This paper studies the shaped charge jet performance in terms of different liner shapes including conical,bell,hemispherical and bi-conical liners.The critical angles and the relevant flow velocities for the zir-conium liner material were calculated analytically and numerically using Autodyn hydro-code.The relationship between the critical collapse angle and the flow velocity was determined for the conditions of jet formation and coherency.Penetration tests according to the standard testing procedures of APL-RP34(Section-I1)were performed to validate the numerical predictions of the jet performance of the studied liners.It was found that the four shaped charge liners all produced coherent jets with different performances.The penetration depth of the shaped charges with the bell and the bi-conical liner shapesincreased by 10.3%and 22%,respectively,while the crater diameter of shaped charge with hemispherical liner increased by 85%representing the formation of an explosively-formed-projectile(EF),when they are compared with the corresponding jet characteristics of a conical liner shaped charge.nanоci 1cu.展开更多
The development of high-efficiency and low-cost catalysts is very crucial for the MeerweinPonndorf-Verley (MPV) reduction of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF). In this ...The development of high-efficiency and low-cost catalysts is very crucial for the MeerweinPonndorf-Verley (MPV) reduction of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF). In this work, an amorphous and mesoporous zirconium phosphonate catalyst (Zr-DTMP), which is a zirconium-containing organic-inorganic nanohybrid, was successfully designed and synthesized by the simple assembly of zirconium tetrachloride (ZrCl4) and diethylene triaminepenta(methylene phosphonic acid)(DTMP). Satisfactorily, when Zr-DTMP was employed for the MPV reduction of HMF in the presence of 2-butanol (secBuOH), DHMF yield could be achieved as 96.5% in 3 h under a relatively mild reaction temperature of 140℃. Systematic investigations indicated that this high catalytic activity should be mainly due to the cooperative role of enhancive Lewis acid site (Zr4+) and Lewis base site (O2-) in activating the carbonyl group of HMF and dissociating the hydroxyl group of secBuOH, respectively. Additionally, Zr-DTMP showed excellent catalytic stability, when it was successively used 5 recycles, its surface characteristics and textural properties still remained almost unchanged, and so, the catalytic activity was not obviously affected. More interestingly, Zr-DTMP could also be applied for the selective reduction of other biomass-derived carbonyl compounds, such as 5-methylfurfural (MF), furfural (FF), levulinic acid (LA), ethyl levulinate (EL) and cyclohexanone (CHN), into the corresponding products with high yields, which is beneficial to the effective synthesis of various valuable bio-based chemicals.展开更多
The preparation of nuclear-grade zirconium and hafnium is very important for nuclear power. The separation of hafnium from zirconium in a hydrochloric acid solution by solvent extraction was investigated with di(2-eth...The preparation of nuclear-grade zirconium and hafnium is very important for nuclear power. The separation of hafnium from zirconium in a hydrochloric acid solution by solvent extraction was investigated with di(2-ethylhexyl)phosphoric acid(D2 EHPA). The effects of hydrochloric acid concentration, extractant concentration,diluents, and temperature on the distribution coefficient of hafnium and zirconium were studied. The species extracted were ZrOA_2·2 HA and HfOA_2-2 HA. In this process, the separation factors varied with different diluents and followed the order octane > hexane > toluene > chloroform.A high separation factor value of 4.16 was obtained under the conditions of a solution containing 0.05 mol/L HCl and0.01 mol/L D2 EHPA for the separation of hafnium from zirconium. The extraction reaction was endothermic.展开更多
Doping enables manipulation of both the electrical and optical properties of halide perovskites.Herein,we incorporated Te^(4+) into Cs_(2)ZrCl_(6) single crystal,simultaneously preserving the vacancy-ordered structure...Doping enables manipulation of both the electrical and optical properties of halide perovskites.Herein,we incorporated Te^(4+) into Cs_(2)ZrCl_(6) single crystal,simultaneously preserving the vacancy-ordered structure,to obtain an efficient yellow-emitting perovskite with a near-unity photoluminescence quantum yield(PLQY≈97.6%).Te^(4+) doping modifies the hue and emission color of pristine Cs_(2)ZrCl_(6),generates new absorption channels,and successfully extends the excitation energy from<280 nm to 360-450 nm range.Detailed spectral characterizations,including ultrafast femtosecond transient absorption measurements,reveal that the bright yellow light is derived from triplet self-trapped excitons.Moreover,further tuning doping concentration enables Te-doped Cs_(2)ZrCl_(6) single crystals to exhibit efficient warm white light emission.This work provides a new perspective for the development and design of stable lead-free perovskites with highly efficient luminescence.展开更多
Efficient and selective production of 5-hydroxymethylfurfural(HMF) from glucose was achieved in the presence of zirconium phosphate(ZrPO) catalyst in a biphasic system.With the use of this catalyst,a high HMF yield of...Efficient and selective production of 5-hydroxymethylfurfural(HMF) from glucose was achieved in the presence of zirconium phosphate(ZrPO) catalyst in a biphasic system.With the use of this catalyst,a high HMF yield of 56.8% was obtained from glucose in a water-tetrahydrofuran(THF) biphasic system.Characterization results showed that such catalyst had weak to strong acid sites and contained both Lewis and Br?nsted acid sites.The results of comparative experiments over some other solid acid catalysts demonstrated that the Lewis acid sites on the ZrPO catalyst played a crucial role in the isomerization of glucose to fructose and the Br?nsted ones were active in the dehydration of generated fructose to HMF.Moreover,less levulinic acid(LA) and formic acid(FA)(0.5%) were detected in the reaction solution,indicating that this ZrPO catalyst exhibited high selectivity towards the formation of HMF.Furthermore,the ZrPO catalyst was very stable and could maintain its activity after being used for six times.展开更多
Sodium-ion-exchangedα-zirconium phosphate(Na-α-ZrP)was synthesized by using disodium hydrogen phosphate as the sodium source,which was an efficient ion exchange way.The tribological properties of Na-α-ZrP as an add...Sodium-ion-exchangedα-zirconium phosphate(Na-α-ZrP)was synthesized by using disodium hydrogen phosphate as the sodium source,which was an efficient ion exchange way.The tribological properties of Na-α-ZrP as an additive in lithium grease were investigated by a four-ball friction tester and a SRV tester,respectively.The synergistic effect of Na-α-ZrP with ZDDP was also studied.Results indicate that Na-α-ZrP can effectively improve the antiwear and friction-reducing properties of lithium grease.Combined with ZDDP,the grease demonstrated excellent anti-wear performance,especially under high loads.The possible wear mechanism was discussed by observing the worn surface using 3D optical profiler,scanning electron microscopy(SEM),energy-dispersive spectrometry(EDS),and X-ray photoelectron spectroscopy(XPS).The simple synthetic method and superior tribological performance make the Na-α-ZrP become a potential choice for lubricant additives.展开更多
This study focuses on the effects of reducing solvents used in the preparation of vanadyl pyrophosphate （VPO）, and ZrO2 and （ZrO）2P2O7 promoters on the structure and catalytic performance of VPO catalysts. The VPO...This study focuses on the effects of reducing solvents used in the preparation of vanadyl pyrophosphate （VPO）, and ZrO2 and （ZrO）2P2O7 promoters on the structure and catalytic performance of VPO catalysts. The VPO catalysts were prepared by the following steps： 1） Formation of vanadium phosphate by the reaction of V2O5 and H3PO4, 2） Synthesis of VPO precursor through the reduction of vanadium phosphate by reducing solvents, and 3） Activation of the precursor. For Zr promoted VPO, Zr was added to the precursor before activation. The P/V atomic ratios of different VPO catalysts, which were prepared by using different reducing solvents, were different. The precursor prepared by using isobutanol or isobutanol-benzyl alcohol contained VO（H2PO4）2 and VOHPO4·0.5H2O. The precursor prepared by using hexanol also contained VO（H2PO4）2 and VOHPO4·0.5H2O crystal phases, but the amount of VOHPO4·0.5H2O was much less than that of VO（H2PO4）2. After activation, all the VPO catalysts, prepared by using different reducing solvents, contained only the （VO）2P2O7 crystal phase. The VPO prepared by using isobutanol-petroleum ether as reducing solvent was the most active, while the VPO prepared by using hexanol had the lowest activity. Nevertheless, their total selectivity to phthalic and maleic anhydrides was almost the same. Both ZrO2 and （ZrO）2P2O7 promoters increased the activity and selectivity of VPO, but ZrO2 promoter increased the activity of VPO more drastically than （ZrO）2P2O7 promoter.展开更多
Molecular dynamics simulations are conducted to study self-interstitial migration in zirconium. By defining crystal lattice points where more than one atom is present in corresponding Wigner-Seitz cells, as the locati...Molecular dynamics simulations are conducted to study self-interstitial migration in zirconium. By defining crystal lattice points where more than one atom is present in corresponding Wigner-Seitz cells, as the locations of self-interstitial atoms （LSIAs）, three types of events are identified as LSIA migrations：the jump remaining in one 〈1120〉 direction （ILJ）, the jump from one 〈1120〉 to another 〈1120〉 direction in the same basal plane （OLJ）, and the jump from one basal plane to an adjacent basal plane （OPJ）. The occurrence frequencies of the three types are calculated. ILJ is found to be a dominant event in a temperature range from 300 K to 1200 K, but the occurrence frequencies of OLJ and OPJ increase with temperature increasing. The total occurrence frequency of all jump types has a good linear dependence on temperature. Moreover, the migration trajectories of LSIAs in the hcp basal-plane is not what is observed if only conventional one-or two-dimensional migrations exists; rather, they exhibit the feature that we call fraction-dimensional. Using Monte Carlo simulations, the potential kinetic effects of fraction-dimensional migration, which is measured by the average number of lattice sites visited per jump event （denoted by nSPE）, are analysed. The significant differences between the nSPE value of the fraction-dimensional migration and those of conventional one-and two-dimensional migrations suggest that the conventional diffusion coefficient cannot give an accurate description of the underlying kinetics of SIAs in Zr. This conclusion could be generally meaningful for the cases where the low-dimensional migration of defects are observed.展开更多
In the present study, we investigated the effect of cerium and erbium doping of the zirconium dioxide matrix. We synthesized doped samples using hydrothermal process. The amounts of dopant used were 0.5%, 1% and 5% mo...In the present study, we investigated the effect of cerium and erbium doping of the zirconium dioxide matrix. We synthesized doped samples using hydrothermal process. The amounts of dopant used were 0.5%, 1% and 5% molar(rare earth oxide over zirconium dioxide) respectively. The samples have been studied via X-ray Diffraction measurements for the structural characterization. UV visible diffuse reflectance was used for the optical analysis, Brunauer-Emmett-Teller(BET) model for the measurement of the surface area. Finally the samples have been analysed via electron paramagnetic resonance(EPR) for the electronic characterization. Then we tested the new synthetized materials to determine their photocatalytic activity in the reaction of degradation of methylene blue performed under irradiation by diodes(LEDs) emitting exclusively visible light.展开更多
Layered material indium selenide(InxSey)is a promising candidate for building next-generation electronic and photonic devices.We report a zirconium aided MBE growth of this van der Waals material.When co-depositing zi...Layered material indium selenide(InxSey)is a promising candidate for building next-generation electronic and photonic devices.We report a zirconium aided MBE growth of this van der Waals material.When co-depositing zirconium and selenium onto an indium phosphide substrate with a substrate temperature of 400℃at a constant zirconium flux rate of 0.01 ML/min,the polymorphic Inx Sey layer emerges on top of the insulating ZrSe2 layer.Different archetypes,such as InSe,α-In2Se3 and α-In2Se3,are found in the InxSey layers.A negative magnetoresistance of 40%at 2 K under 9 T magnetic field is observed.Such an InxSeyZrSe2 heterostructure with good lattice-matching may serve as a candidate for device applications.展开更多
Zirconium tritiated(ZrTx)is an alternative target material for deuteron-triton(D-T)reaction neutron generator.The isotopic replacement and microstructure evolution induced by hydrogen isotope implantation could signif...Zirconium tritiated(ZrTx)is an alternative target material for deuteron-triton(D-T)reaction neutron generator.The isotopic replacement and microstructure evolution induced by hydrogen isotope implantation could significantly affect the performance of the target film.In this work,the zirconium deuteride film deposited on Mo/Si substrate was implanted by 150 keV protons with fluence from 1×10^(16 ) to 1×10^(18 )protons/cm^(2).After implantation,the depth profiles of retained hydrogen(H)and deuterium(D)in these target films were analyzed by elastic recoil detection analysis(ERDA),and time of flight-secondary ion mass spectrometry(ToF-SIMS).Additionally,the microstructure evolution was also observed by x-ray diffraction(XRD)and scanning electron microscope(SEM).The D concentration in the ZrDx film decreased versus the proton implantation fluence.An analytical model was proposed to describe the hydrogen isotopic trapping and exchange as functions of incident protons fluence.Additionally,the XRD analysis revealed that no new phase was formed after proton implantation.Furthermore,circular flakings were observed on the ZrDx surface from SEM images at fluence up to 1×10^(18) protons/cm^(2),and this surface morphology was considered to associate with the hydrogen atoms congregation in Mo/Si boundary.展开更多
Disulfide zirconium(ZrS_(2)) is a two-dimensional(2D) transition metal disulfide and has given rise to extensive attention because of its distinctive electronic structure and properties.However,mass production of high...Disulfide zirconium(ZrS_(2)) is a two-dimensional(2D) transition metal disulfide and has given rise to extensive attention because of its distinctive electronic structure and properties.However,mass production of high quality of ZrS_(2)nanosheets to realize their practical application remains a challenge.Here,we have successfully exfoliated the bulk ZrS_(2)powder with the thickness of micron into single and few-layer nanosheets through liquid-phase exfoliation in N-methylpyrrolidone(NMP) assisted via aliphatic amines as intercalators.It is found that the exfoliation yield is as high as 27.3%,which is the record value for the exfoliation of ZrS_(2)nanosheets from bulk ZrS_(2)powder,and 77.1% of ZrS_(2)nanosheets are 2-3 layers.The molecular geometric size and aliphatic amine basicity have important impact on the exfoliation.Furthermore,the ZrS_(2)nanosheets have been used as catalyst in the electrocatalytic dinitrogen reduction with the NH3yield of 57.75 μg h^(-1)mg_(cat.)^(-1),which is twice that by ZrS_(2)nanofibers reported in literature and three times that by the bulk ZrS_(2)powder.Therefore,the liquid phase exfoliation strategy reported here has great potential in mass production of ZrS_(2)nanosheets for high activity electrocatalysis.展开更多
Catalytic hydrogenolysis of aromatic ether bonds is a highly promising strategy for upgrading lignin into small-molecule chemicals,which relies on developing innovative heterogeneous catalysts with high activity.Herei...Catalytic hydrogenolysis of aromatic ether bonds is a highly promising strategy for upgrading lignin into small-molecule chemicals,which relies on developing innovative heterogeneous catalysts with high activity.Herein,we designed porous zirconium phosphate nanosheet-supported Ru nanocatalysts(Ru/ZrPsheet)as the heterogeneous catalyst by a process combining ball milling and molten-salt(KNO_(3)).Very interestingly,the fabricated Ru/ZrPsheetshowed good catalytic performance on the transfer hydrogenolysis of various types of aromatic ether bonds contained in lignin,i.e.,4-O-5,a-O-4,β-O-4,and aryl-O-CH3,over a low Ru usage(<0.5 mol%)without using any acidic/basic additive.Detailed investigations indicated that the properties of Ru and the support were indispensable.The excellent activity of Ru/ZZrPsheetoriginated from the strong acidity and basicity of ZrPsheetand the higher electron density of metallic Ru0as well as the nanosheet structure of ZrPsheet.展开更多
The non-equilibrium molecular dynamics method is adapted to calculate the phonon thermal conductivity of alphazirconium. By exchanging velocities of atoms in different regions, the stable heat flux and the temperature...The non-equilibrium molecular dynamics method is adapted to calculate the phonon thermal conductivity of alphazirconium. By exchanging velocities of atoms in different regions, the stable heat flux and the temperature gradient are established to calculate the thermal conductivity. The phonon thermal conductivities under different conditions, such as different heat exchange frequencies, different temperatures, different crystallographic orientations, and crossing grain boundary （GB）, are studied in detail with considering the finite size effect. It turns out that the phonon thermal conductivity decreases with the increase of temperature, and displays anisotropies along different crystallographic orientations. The phonon thermal conductivity in [0001] direction （close-packed plane） is largest, while the values in other two directions of [2īī0] and [01ī0] are relatively close. In the region near GB, there is a sharp temperature drop, and the phonon thermal conductivity is about one-tenth of that of the single crystal at 550 K, suggesting that the GB may act as a thermal barrier in the crystal.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.U2230401,U1930401,and 12004048)the National Key Research and Development Program of China (Grant No.2021YFB3501503)+1 种基金the Science Challenge Project (Grant No.TZ2018002)the Foundation of LCP。
文摘Hydride precipitation in zirconium cladding materials can damage their integrity and durability.Service temperature and material defects have a significant effect on the dynamic growth of hydrides.In this study,we have developed a phasefield model based on the assumption of elastic behaviour within a specific temperature range(613 K-653 K).This model allows us to study the influence of temperature and interfacial effects on the morphology,stress,and average growth rate of zirconium hydride.The results suggest that changes in temperature and interfacial energy influence the length-to-thickness ratio and average growth rate of the hydride morphology.The ultimate determinant of hydride orientation is the loss of interfacial coherency,primarily induced by interfacial dislocation defects and quantifiable by the mismatch degree q.An escalation in interfacial coherency loss leads to a transition of hydride growth from horizontal to vertical,accompanied by the onset of redirection behaviour.Interestingly,redirection occurs at a critical mismatch level,denoted as qc,and remains unaffected by variations in temperature and interfacial energy.However,this redirection leads to an increase in the maximum stress,which may influence the direction of hydride crack propagation.This research highlights the importance of interfacial coherency and provides valuable insights into the morphology and growth kinetics of hydrides in zirconium alloys.
基金Project supported by the Joint Fund of the National Natural Science Foundation of China–“Ye Qisun”Science Fund(Grant No.U2341251)。
文摘Zirconium hydride(ZrH_(2)) is an ideal neutron moderator material. However, radiation effect significantly changes its properties, which affect its behavior and the lifespan of the reactor. The threshold energy of displacement is an important quantity of the number of radiation defects produced, which helps us to predict the evolution of radiation defects in ZrH_(2).Molecular dynamics(MD) and ab initio molecular dynamics(AIMD) are two main methods of calculating the threshold energy of displacement. The MD simulations with empirical potentials often cannot accurately depict the transitional states that lattice atoms must surpass to reach an interstitial state. Additionally, the AIMD method is unable to perform largescale calculation, which poses a computational challenge beyond the simulation range of density functional theory. Machine learning potentials are renowned for their high accuracy and efficiency, making them an increasingly preferred choice for molecular dynamics simulations. In this work, we develop an accurate potential energy model for the ZrH_(2) system by using the deep-potential(DP) method. The DP model has a high degree of agreement with first-principles calculations for the typical defect energy and mechanical properties of the ZrH_(2) system, including the basic bulk properties, formation energy of point defects, as well as diffusion behavior of hydrogen and zirconium. By integrating the DP model with Ziegler–Biersack–Littmark(ZBL) potential, we can predict the threshold energy of displacement of zirconium and hydrogen in ε-ZrH_(2).
文摘Two-dimensional diagnosis of laser-induced zirconium(Zr)plasma has been experimentally performed using the time-of-flight method by employing Faraday cups in addition to electric and magnetic probes.The characteristic parameters of laser-induced Zr plasma have been evaluated as a function of different laser irradiances ranging from 4.5 to 11.7 GW cm-2 at different axial positions of 1–4 cm with a fixed radial distance of 2 cm.A well-supporting correlation between the plume parameters and the laser-plasma-produced spontaneous electric and magnetic(E and B)fields was established.The measurements of the characteristic parameters and spontaneously induced fields were observed to have an increasing trend with the increasing laser irradiance.However,when increasing the spatial distance in both the axial and radial directions,the plasma parameters(electron/ion number density,temperature and kinetic energy)did not show either continuously increasing or decreasing trends due to various kinetic and dynamic processes during the spatial evolution of the plume.However,the E and B fields were observed to be always diffusing away from the target.The radial component of electron number densities remained higher than the axial number density component,whereas the axial ion number density at all laser irradiances and axial distances remained higher than the radial ion number density.The higher axial self-generated electric field(SGEF)values than radial SGEF values are correlated with the effective charge-separation mechanism of electrons and ions.The generation of a self-generated magnetic field is observed dominantly in the radial direction at increasing laser irradiance as compared to the axial one due to the deflection of fast-moving electrons and the persistence of two-electron temperature on the radial axis.
基金Financial support from National Natural Science Foundation of China(nos 11205136 and 11505145)the Research Fund for Doctoral Program of Southwest University of Science and Technology(no.l4zx7166)
文摘In order to understand the dnve-in target in a D-D type neutron generator,it is essential to study the mechanism of the interaction between hydrogen ion beams and the hydrogenabsorbing metal film.The present research concerns the nucleation of hydride within zirconium film implanted with hydrogen ions.Doses of 30 keV hydrogen ions ranging from 4.30×10^（17） to1.43×10^（18） ions cm^（-2） were loaded into the zirconium film through the ion beam implantation technique.Features of the surface morphology and transformation of phase structures were investigated with scanning electron microscopy,atomic force microscopy and x-ray diffraction.Confirmation of the formation of 5 phase zirconium hydride in the implanted samples was first made by x-ray diffraction,and the different stages in the gradual nucleation and growth of zirconium hydride were then observed by atomic force microscope and scanning electron microscopy.
基金Project supported by the National Key Basic Research and Development Programme of China （Grant No 2001CB610504） and the National Natural Science Foundation of China （Grant Nos 60576039 and 10374060）.Acknowledgments We thank Dr Wang Zhuo and Dr Yang ChangHong for their assistance in the experiment.
文摘Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency （RF） msgnetron sputtering at room temperature, The RF power is varied from 75 to 150 W. At first the crystallinity and conductivity of the film are improved and then both of them show deterioration with the increase of the RF power, The lowest resistivity achieved is 2.07 × 10^-3Ωcm at an RF power of 100W with a Hall mobility of 16cm^2V^-1s^-1 and a carrier concentration of 1.95 × 10^20 cm^-3. The films obtained are polycryetalline with a hexagonal structure and a preferred orientation along the c-axis, All the films have a high transmittance of approximately 92% in the visible range. The optical band gap is about 3.33 eV for the films deposited at different RF powers.
基金supported by the National Natural Science Foundation of China(No.21076151)
文摘Co/SiO2 and zirconium promoted Co/Zr/SiO2 catalysts were prepared using dielectric-barrier discharge （DBD） plasma instead of the conventional thermal calcination method. Fischer-Tropseh Synthesis （FTS） performances of the catalyst were evaluated in a fixed bed reactor. The results indicated that the catalyst treated by DBD plasma shows the higher FTS activity and yield of heavy hydrocarbons as compared with that treated by the conventional thermal calcination method. Increase in CO conversion was unnoticeable on the Co/SiO2 catalyst, but significant on the Co/Zr/SiO2 catalyst, both prepared by DBD plasma. On the other hand, heavy hydrocarbon selectivity and chain growth probability （a value） were enhanced on all the catalysts prepared by the DBD plasma. In order to study the effect of the DBD plasma treatment on the FTS performance, the catalysts were characterized by N2-physisorption, H2-temperature programed reduction （H2-TPR）, H2-temperature- programmed desorption （H2-TPD） and oxygen titration, transmission electron microscope （TEM） and X-ray diffraction （XRD）. It was proved that, compared with the traditional calcination method, DBD plasma not only could shorten the precursor decomposition time, but also could achieve better cobalt dispersion, smaller Co304 cluster size and more uniform cobalt distribution. However, cobalt reducibility was hindered to some extent in the Co/SiO2 catalyst prepared by DBD plasma, while the zirconium additive prevented significantly the decrease in cobalt reducibility and increased cobalt dispersion as well as the FTS performance.
文摘This paper studies the shaped charge jet performance in terms of different liner shapes including conical,bell,hemispherical and bi-conical liners.The critical angles and the relevant flow velocities for the zir-conium liner material were calculated analytically and numerically using Autodyn hydro-code.The relationship between the critical collapse angle and the flow velocity was determined for the conditions of jet formation and coherency.Penetration tests according to the standard testing procedures of APL-RP34(Section-I1)were performed to validate the numerical predictions of the jet performance of the studied liners.It was found that the four shaped charge liners all produced coherent jets with different performances.The penetration depth of the shaped charges with the bell and the bi-conical liner shapesincreased by 10.3%and 22%,respectively,while the crater diameter of shaped charge with hemispherical liner increased by 85%representing the formation of an explosively-formed-projectile(EF),when they are compared with the corresponding jet characteristics of a conical liner shaped charge.nanоci 1cu.
基金financially supported by the National Natural Science Foundation of China (21506071)the Special Foundation of Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection (HSXT2-316)
文摘The development of high-efficiency and low-cost catalysts is very crucial for the MeerweinPonndorf-Verley (MPV) reduction of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF). In this work, an amorphous and mesoporous zirconium phosphonate catalyst (Zr-DTMP), which is a zirconium-containing organic-inorganic nanohybrid, was successfully designed and synthesized by the simple assembly of zirconium tetrachloride (ZrCl4) and diethylene triaminepenta(methylene phosphonic acid)(DTMP). Satisfactorily, when Zr-DTMP was employed for the MPV reduction of HMF in the presence of 2-butanol (secBuOH), DHMF yield could be achieved as 96.5% in 3 h under a relatively mild reaction temperature of 140℃. Systematic investigations indicated that this high catalytic activity should be mainly due to the cooperative role of enhancive Lewis acid site (Zr4+) and Lewis base site (O2-) in activating the carbonyl group of HMF and dissociating the hydroxyl group of secBuOH, respectively. Additionally, Zr-DTMP showed excellent catalytic stability, when it was successively used 5 recycles, its surface characteristics and textural properties still remained almost unchanged, and so, the catalytic activity was not obviously affected. More interestingly, Zr-DTMP could also be applied for the selective reduction of other biomass-derived carbonyl compounds, such as 5-methylfurfural (MF), furfural (FF), levulinic acid (LA), ethyl levulinate (EL) and cyclohexanone (CHN), into the corresponding products with high yields, which is beneficial to the effective synthesis of various valuable bio-based chemicals.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR201702160381)
文摘The preparation of nuclear-grade zirconium and hafnium is very important for nuclear power. The separation of hafnium from zirconium in a hydrochloric acid solution by solvent extraction was investigated with di(2-ethylhexyl)phosphoric acid(D2 EHPA). The effects of hydrochloric acid concentration, extractant concentration,diluents, and temperature on the distribution coefficient of hafnium and zirconium were studied. The species extracted were ZrOA_2·2 HA and HfOA_2-2 HA. In this process, the separation factors varied with different diluents and followed the order octane > hexane > toluene > chloroform.A high separation factor value of 4.16 was obtained under the conditions of a solution containing 0.05 mol/L HCl and0.01 mol/L D2 EHPA for the separation of hafnium from zirconium. The extraction reaction was endothermic.
基金supported by the National Natural Science Foundation of China (21833009, 22088102)the National Key Research and Development Program of China (2017YFA0204800)+5 种基金the Scientific Instrument Developing Project of the Chinese Academy of Sciences (YJKYYQ20190003)the Innovation Foundation of Dalian Institute of Chemical Physics (DICP I202127)the Liao Ning Revitalization Talents Program (XLYC1802126, XLYC1907053)the Dalian City Foundation for Science and Technology Innovation (2019J12GX031)the CAS Youth Innovation Promotion Association (2018220)China Postdoctoral Science Foundation (2020 M670800)。
文摘Doping enables manipulation of both the electrical and optical properties of halide perovskites.Herein,we incorporated Te^(4+) into Cs_(2)ZrCl_(6) single crystal,simultaneously preserving the vacancy-ordered structure,to obtain an efficient yellow-emitting perovskite with a near-unity photoluminescence quantum yield(PLQY≈97.6%).Te^(4+) doping modifies the hue and emission color of pristine Cs_(2)ZrCl_(6),generates new absorption channels,and successfully extends the excitation energy from<280 nm to 360-450 nm range.Detailed spectral characterizations,including ultrafast femtosecond transient absorption measurements,reveal that the bright yellow light is derived from triplet self-trapped excitons.Moreover,further tuning doping concentration enables Te-doped Cs_(2)ZrCl_(6) single crystals to exhibit efficient warm white light emission.This work provides a new perspective for the development and design of stable lead-free perovskites with highly efficient luminescence.
基金supported financially by the National Science Foundation of China(No.21273071)the Science and Technology Commission of Shanghai Municipality(13520711400,13JC1401902,10dz2220500)the Fundamental Research Funds for the Central Universities of China and the SINOPEC project(No.115046)
文摘Efficient and selective production of 5-hydroxymethylfurfural(HMF) from glucose was achieved in the presence of zirconium phosphate(ZrPO) catalyst in a biphasic system.With the use of this catalyst,a high HMF yield of 56.8% was obtained from glucose in a water-tetrahydrofuran(THF) biphasic system.Characterization results showed that such catalyst had weak to strong acid sites and contained both Lewis and Br?nsted acid sites.The results of comparative experiments over some other solid acid catalysts demonstrated that the Lewis acid sites on the ZrPO catalyst played a crucial role in the isomerization of glucose to fructose and the Br?nsted ones were active in the dehydration of generated fructose to HMF.Moreover,less levulinic acid(LA) and formic acid(FA)(0.5%) were detected in the reaction solution,indicating that this ZrPO catalyst exhibited high selectivity towards the formation of HMF.Furthermore,the ZrPO catalyst was very stable and could maintain its activity after being used for six times.
基金This work was supported by the National Natural Science Foundation of China(No.21436008,No.21978186 and No.22078218)the Natural Science Foundation of Shanxi Province(No.201901D111122).
文摘Sodium-ion-exchangedα-zirconium phosphate(Na-α-ZrP)was synthesized by using disodium hydrogen phosphate as the sodium source,which was an efficient ion exchange way.The tribological properties of Na-α-ZrP as an additive in lithium grease were investigated by a four-ball friction tester and a SRV tester,respectively.The synergistic effect of Na-α-ZrP with ZDDP was also studied.Results indicate that Na-α-ZrP can effectively improve the antiwear and friction-reducing properties of lithium grease.Combined with ZDDP,the grease demonstrated excellent anti-wear performance,especially under high loads.The possible wear mechanism was discussed by observing the worn surface using 3D optical profiler,scanning electron microscopy(SEM),energy-dispersive spectrometry(EDS),and X-ray photoelectron spectroscopy(XPS).The simple synthetic method and superior tribological performance make the Na-α-ZrP become a potential choice for lubricant additives.
文摘This study focuses on the effects of reducing solvents used in the preparation of vanadyl pyrophosphate （VPO）, and ZrO2 and （ZrO）2P2O7 promoters on the structure and catalytic performance of VPO catalysts. The VPO catalysts were prepared by the following steps： 1） Formation of vanadium phosphate by the reaction of V2O5 and H3PO4, 2） Synthesis of VPO precursor through the reduction of vanadium phosphate by reducing solvents, and 3） Activation of the precursor. For Zr promoted VPO, Zr was added to the precursor before activation. The P/V atomic ratios of different VPO catalysts, which were prepared by using different reducing solvents, were different. The precursor prepared by using isobutanol or isobutanol-benzyl alcohol contained VO（H2PO4）2 and VOHPO4·0.5H2O. The precursor prepared by using hexanol also contained VO（H2PO4）2 and VOHPO4·0.5H2O crystal phases, but the amount of VOHPO4·0.5H2O was much less than that of VO（H2PO4）2. After activation, all the VPO catalysts, prepared by using different reducing solvents, contained only the （VO）2P2O7 crystal phase. The VPO prepared by using isobutanol-petroleum ether as reducing solvent was the most active, while the VPO prepared by using hexanol had the lowest activity. Nevertheless, their total selectivity to phthalic and maleic anhydrides was almost the same. Both ZrO2 and （ZrO）2P2O7 promoters increased the activity and selectivity of VPO, but ZrO2 promoter increased the activity of VPO more drastically than （ZrO）2P2O7 promoter.
基金Project supported by the National Natural Science Foundation of China(Grant No.91126001)the National Magnetic Confinement Fusion Program of China(Grant No.2013GB109002)
文摘Molecular dynamics simulations are conducted to study self-interstitial migration in zirconium. By defining crystal lattice points where more than one atom is present in corresponding Wigner-Seitz cells, as the locations of self-interstitial atoms （LSIAs）, three types of events are identified as LSIA migrations：the jump remaining in one 〈1120〉 direction （ILJ）, the jump from one 〈1120〉 to another 〈1120〉 direction in the same basal plane （OLJ）, and the jump from one basal plane to an adjacent basal plane （OPJ）. The occurrence frequencies of the three types are calculated. ILJ is found to be a dominant event in a temperature range from 300 K to 1200 K, but the occurrence frequencies of OLJ and OPJ increase with temperature increasing. The total occurrence frequency of all jump types has a good linear dependence on temperature. Moreover, the migration trajectories of LSIAs in the hcp basal-plane is not what is observed if only conventional one-or two-dimensional migrations exists; rather, they exhibit the feature that we call fraction-dimensional. Using Monte Carlo simulations, the potential kinetic effects of fraction-dimensional migration, which is measured by the average number of lattice sites visited per jump event （denoted by nSPE）, are analysed. The significant differences between the nSPE value of the fraction-dimensional migration and those of conventional one-and two-dimensional migrations suggest that the conventional diffusion coefficient cannot give an accurate description of the underlying kinetics of SIAs in Zr. This conclusion could be generally meaningful for the cases where the low-dimensional migration of defects are observed.
基金supported by the CARIPLO Foundation with the Advanced Materials Grant 2013 "Development of second generation photocatalysts for energy and environment"the Local Funding of the University of Torino call_2014_L2_126
文摘In the present study, we investigated the effect of cerium and erbium doping of the zirconium dioxide matrix. We synthesized doped samples using hydrothermal process. The amounts of dopant used were 0.5%, 1% and 5% molar(rare earth oxide over zirconium dioxide) respectively. The samples have been studied via X-ray Diffraction measurements for the structural characterization. UV visible diffuse reflectance was used for the optical analysis, Brunauer-Emmett-Teller(BET) model for the measurement of the surface area. Finally the samples have been analysed via electron paramagnetic resonance(EPR) for the electronic characterization. Then we tested the new synthetized materials to determine their photocatalytic activity in the reaction of degradation of methylene blue performed under irradiation by diodes(LEDs) emitting exclusively visible light.
基金Supported by the National Natural Science Foundation of China(Grant No.11874233).
文摘Layered material indium selenide(InxSey)is a promising candidate for building next-generation electronic and photonic devices.We report a zirconium aided MBE growth of this van der Waals material.When co-depositing zirconium and selenium onto an indium phosphide substrate with a substrate temperature of 400℃at a constant zirconium flux rate of 0.01 ML/min,the polymorphic Inx Sey layer emerges on top of the insulating ZrSe2 layer.Different archetypes,such as InSe,α-In2Se3 and α-In2Se3,are found in the InxSey layers.A negative magnetoresistance of 40%at 2 K under 9 T magnetic field is observed.Such an InxSeyZrSe2 heterostructure with good lattice-matching may serve as a candidate for device applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.11905206 and 11975217).
文摘Zirconium tritiated(ZrTx)is an alternative target material for deuteron-triton(D-T)reaction neutron generator.The isotopic replacement and microstructure evolution induced by hydrogen isotope implantation could significantly affect the performance of the target film.In this work,the zirconium deuteride film deposited on Mo/Si substrate was implanted by 150 keV protons with fluence from 1×10^(16 ) to 1×10^(18 )protons/cm^(2).After implantation,the depth profiles of retained hydrogen(H)and deuterium(D)in these target films were analyzed by elastic recoil detection analysis(ERDA),and time of flight-secondary ion mass spectrometry(ToF-SIMS).Additionally,the microstructure evolution was also observed by x-ray diffraction(XRD)and scanning electron microscope(SEM).The D concentration in the ZrDx film decreased versus the proton implantation fluence.An analytical model was proposed to describe the hydrogen isotopic trapping and exchange as functions of incident protons fluence.Additionally,the XRD analysis revealed that no new phase was formed after proton implantation.Furthermore,circular flakings were observed on the ZrDx surface from SEM images at fluence up to 1×10^(18) protons/cm^(2),and this surface morphology was considered to associate with the hydrogen atoms congregation in Mo/Si boundary.
基金the financial supports from the National Natural Science Foundation of China (No.U1704251 and 21733011)the National Key Research and Development Program of China (2017YFA0403101)+1 种基金Natural Science Foundation of Henan province (No.202300410220)the 111 Project (No.D17007)。
文摘Disulfide zirconium(ZrS_(2)) is a two-dimensional(2D) transition metal disulfide and has given rise to extensive attention because of its distinctive electronic structure and properties.However,mass production of high quality of ZrS_(2)nanosheets to realize their practical application remains a challenge.Here,we have successfully exfoliated the bulk ZrS_(2)powder with the thickness of micron into single and few-layer nanosheets through liquid-phase exfoliation in N-methylpyrrolidone(NMP) assisted via aliphatic amines as intercalators.It is found that the exfoliation yield is as high as 27.3%,which is the record value for the exfoliation of ZrS_(2)nanosheets from bulk ZrS_(2)powder,and 77.1% of ZrS_(2)nanosheets are 2-3 layers.The molecular geometric size and aliphatic amine basicity have important impact on the exfoliation.Furthermore,the ZrS_(2)nanosheets have been used as catalyst in the electrocatalytic dinitrogen reduction with the NH3yield of 57.75 μg h^(-1)mg_(cat.)^(-1),which is twice that by ZrS_(2)nanofibers reported in literature and three times that by the bulk ZrS_(2)powder.Therefore,the liquid phase exfoliation strategy reported here has great potential in mass production of ZrS_(2)nanosheets for high activity electrocatalysis.
基金financially supported by the National Natural Science Foundation of China(22072157,22293012,22179132,22121002)。
文摘Catalytic hydrogenolysis of aromatic ether bonds is a highly promising strategy for upgrading lignin into small-molecule chemicals,which relies on developing innovative heterogeneous catalysts with high activity.Herein,we designed porous zirconium phosphate nanosheet-supported Ru nanocatalysts(Ru/ZrPsheet)as the heterogeneous catalyst by a process combining ball milling and molten-salt(KNO_(3)).Very interestingly,the fabricated Ru/ZrPsheetshowed good catalytic performance on the transfer hydrogenolysis of various types of aromatic ether bonds contained in lignin,i.e.,4-O-5,a-O-4,β-O-4,and aryl-O-CH3,over a low Ru usage(<0.5 mol%)without using any acidic/basic additive.Detailed investigations indicated that the properties of Ru and the support were indispensable.The excellent activity of Ru/ZZrPsheetoriginated from the strong acidity and basicity of ZrPsheetand the higher electron density of metallic Ru0as well as the nanosheet structure of ZrPsheet.
基金the National Basic Research Program of China(Grant No.2010CB731601)
文摘The non-equilibrium molecular dynamics method is adapted to calculate the phonon thermal conductivity of alphazirconium. By exchanging velocities of atoms in different regions, the stable heat flux and the temperature gradient are established to calculate the thermal conductivity. The phonon thermal conductivities under different conditions, such as different heat exchange frequencies, different temperatures, different crystallographic orientations, and crossing grain boundary （GB）, are studied in detail with considering the finite size effect. It turns out that the phonon thermal conductivity decreases with the increase of temperature, and displays anisotropies along different crystallographic orientations. The phonon thermal conductivity in [0001] direction （close-packed plane） is largest, while the values in other two directions of [2īī0] and [01ī0] are relatively close. In the region near GB, there is a sharp temperature drop, and the phonon thermal conductivity is about one-tenth of that of the single crystal at 550 K, suggesting that the GB may act as a thermal barrier in the crystal.
