Vanadium flow batteries(VFB)offer an ideal solution to the issue of storing massive amounts of electricity produced from intermittent renewables.However,the historical challenge of high thermal precipitation of V_(2)O...Vanadium flow batteries(VFB)offer an ideal solution to the issue of storing massive amounts of electricity produced from intermittent renewables.However,the historical challenge of high thermal precipitation of V_(2)O_(5)from VO_(2)^(+)(~50℃for 1 day)represents a critical concern.Temperature control can alleviate the problem to a certain extent,however,at the expense of the cost of system design and operation.Herein,we report stable electrolyte chemistry at high temperature.By introducing Cr^(3+)as a stabilizer,it bridges with VO_(2)^(+)to form a Cr—O—V^(Ⅴ)structure,which reduces the electron cloud density of V.Therefore,it combines more tightly with H_(2)O and prevents its dehydration process.In addition,the dimerization process of VO_(2)^(+)is also inhibited due to the occupancy of Cr^(3+).As a result,a formed 1.5 M VO_(2)^(+)electrolyte demonstrates a high stability for over 30 days at 50℃(v.s.blank for<1 day at 50℃).Additionally,the low-temperature precipitation temperature of V^(2+)on the negative side has been reduced from 0℃of commercial electrolytes to-5℃.As a proof of concept,a VFB assembled with Nafion 115 membrane demonstrates an energy efficiency(EE)of 80%at 120 mA cm^(-2)for 1000 cycles(50℃).Most importantly,a 4 kW stack can continuously run for~1000 cycles with EE of 80%at 120 mA cm^(-2)without any heat management.Combined with high thermal stability and excellent performance,our design will certainly provide new impetus for the further commercialization of VFB batteries.展开更多
In order to analyze the influence of the addition of yttrium and manganese on the soot combustion performance and high temperature stability of CeO_(2) catalyst,a series of Y/Mn-modified CeO_(2) catalysts were prepare...In order to analyze the influence of the addition of yttrium and manganese on the soot combustion performance and high temperature stability of CeO_(2) catalyst,a series of Y/Mn-modified CeO_(2) catalysts were prepared.The effects of structural properties,textural properties,oxygen vacancies,Ce^(3+),surface adsorbed oxygen species,reduction properties and desorption properties of oxygen species on the activity were analyzed by various characterization methods.The results of the activity test show that the addition of manganese is beneficial to enhancement of the activity,while the addition of yttrium increases the amount of reactive oxygen species,but decreases the activity.After aging at 700℃,the activity of the CeMn catalyst decreases most sharply,while the catalytic activity of the CeY catalyst can be maintained to a certain extent.Interestingly,the addition of yttrium and manganese at the same time can stabilize the activity.The fundamental reason is that yttrium and manganese move to the surface of the solid solution after aging,which increases the reduction performance of the catalyst,thus contributing to the increase of activity.Although the activity of CeYMn catalyst decreases after aging at 800℃,it is still higher than that of other catalysts aged at 700℃.展开更多
The rapid growth of new electromechanical applications has increased the demand for ferroelectric ce-ramics with excellent piezoelectric properties and a wide temperature operating range.However,achiev-ing robust piez...The rapid growth of new electromechanical applications has increased the demand for ferroelectric ce-ramics with excellent piezoelectric properties and a wide temperature operating range.However,achiev-ing robust piezoelectricity and temperature stability simultaneously in lead zirconate titanate(Pb(Zr,Ti)O_(3))based piezoelectric ceramics poses a significant challenge.This study proposes a new material system of 0.98Pb_(0.84)Ba_(0.16)(Zr_(2/3)Ti_(1/3))O_(3)-0.02Pb(Sb_(1/2)Nb_(1/2))O_(3)+x wt.%Sm_(2)O_(3)(PBZT-PSN-x Sm)to address this challenge.Remarkably,the ceramics x=0.4 demonstrate excellent piezoelectric properties(includ-ing piezoelectric coefficient d33 of 610 pC/N and Curie temperature TC of 290℃)and favorable tem-perature stability(i.e.,d33 varies less than 10%within 25-200℃).The high piezoelectric properties arise from the optimized phase fraction between rhombohedral(R)and tetragonal(T)phases and the increased grain size,which enhance the lattice distortion and the domain switching under electric fields,respectively.The superior temperature stability can be attributed to stable crystal structure and domain structure.These findings indicate that PBZT-PSN-x Sm ceramics hold great promise for practical utilization in high-temperature transducers and sensors.展开更多
The novel nitride-based luminescent materials have received much attention since the end of the last century. In this paper, the commercial Eu2＋-activated nitride red phosphors, Sr1.95Si5N8：Eu0.05, Sr1.85Si5N8：Eu0....The novel nitride-based luminescent materials have received much attention since the end of the last century. In this paper, the commercial Eu2＋-activated nitride red phosphors, Sr1.95Si5N8：Eu0.05, Sr1.85Si5N8：Eu0.15 and Ca0.99AlSiN3：Eu0.01 phosphors were an-nealed at different temperatures （beyond 300 oC） to investigate the dependence of their luminescence performance and structure vari-ability on the temperature. By photoluminescence spectra, X-ray diffraction （XRD） and thermogravimetry-differential scanning calo-rimetry （TG-DSC） analysis, the high temperature stability of the hosts and activator of the three samples were disclosed. With the an-nealing temperature increasing, the activator Eu2＋ions were firstly oxidized and then host in Sr1.95Si5N8：Eu0.05 and Sr1.85Si5N8：Eu0.15, but for Ca0.99AlSiN3：Eu0.01, only the oxidation of the host could be observed, which would lead to the luminescence degradation and even failure of these phosphors. The activator Eu2＋ions were much more stable in CaAlSiN3：Eu than Sr2Si5N8：Eu due to their crystal surroundings, and its concentration also influenced the temperature stability of Sr2Si5N8：Eu.展开更多
A series of the samples La_(1-x)(Sr_(1-y)Na_y)_xMnO_3(y=0.0,0.2,0.4,0.6,0.8,1.0) were prepared by the solid-state reaction method.Magnetoresistance enhancement and temperature stability of magnetoresistance in the sys...A series of the samples La_(1-x)(Sr_(1-y)Na_y)_xMnO_3(y=0.0,0.2,0.4,0.6,0.8,1.0) were prepared by the solid-state reaction method.Magnetoresistance enhancement and temperature stability of magnetoresistance in the system La_(1-x)(Sr_(1-y)Na_y)_xMnO_3 with unchanged Mn^(3+)/Mn^(4+) ratio through the doping of both monovalent and divalent elements at A site were studied through the measurements of X-ray diffraction(XRD) patterns,resistivity-temperature(ρ-T) curves and magnetoresistance-temperature(MR-T) curves.The results indicate that with the increase of Na doping amount,the peak value of MR increases,and it increases from 12.4% for y=0.2 to 50.6% for y=1.0 in the magnetic field B=0.8 T;ρ-T curves exhibit the double-peak phenomenon,which comes from the competition between the resistivity of surface phase and that of body phase;for the sample of y=0.8,MR increases slowly from 8.3% to 9.4% in the temperature range from 259 to 179 K,and MR is so stable in such a wide temperature range,which provides reference for the research on the temperature stability of MR.展开更多
In this work,a novel high entropy perovskite oxide(1-x)(Na_(0.2)Bi_(0.2)Ba_(0.2)Sr_(0.2)Ca_(0.2))TiO_(3-x)NaNbO_(3)(abbrevi-ated as(1-x)NBBSCT-x NN,x=0,0.05,0.1,0.15,and 0.2)was designed to improve temperature dielect...In this work,a novel high entropy perovskite oxide(1-x)(Na_(0.2)Bi_(0.2)Ba_(0.2)Sr_(0.2)Ca_(0.2))TiO_(3-x)NaNbO_(3)(abbrevi-ated as(1-x)NBBSCT-x NN,x=0,0.05,0.1,0.15,and 0.2)was designed to improve temperature dielectric stability and energy storage performance by combining relaxor and antiferroelectric characteristics.The optimal composition of x=0.2 exhibits a high energy storage density of 3.51 J/cm^(3),together with wide temperature stable stability(■<15%,-70 to 110℃),excellent frequency stability(W rec andηvary by only±2.1%and±5.2%within the range of 1-600 Hz)and fast discharge rate(t_(0.9)=55.2 ns).This is mainly due to the enhancement of relaxation behavior and increase of E b caused by the decrease of grain size.These results offer a new strategy for designing high entropy ceramic materials of high performance in the future.展开更多
The ceramics with Pb1.04Zr0.52Ti0.48O3 ＋ z wt.% Cr2O3 were prepared using the traditional technique. The effects of Cr2O3 doping on the phase structure, the microstructure, and the electrical properties of ceramics w...The ceramics with Pb1.04Zr0.52Ti0.48O3 ＋ z wt.% Cr2O3 were prepared using the traditional technique. The effects of Cr2O3 doping on the phase structure, the microstructure, and the electrical properties of ceramics were investigated. Meanwhile, the temperature stabilities of the resonant frequency （fx） were studied. The results showed that the △fr/fr,25℃ decreased with the addition of 0.2 wt.% - 0.8 wt.% Cr2O3 as compared with the undoped samples. The minimum value （-0.182%） of △fr/fr,25℃ was obtained for z = 0.6 wt.% Cr2O3 samples that sintered at 1260℃. The values of ε^τ33/ε0 = 1650, tanδ = 0.006, d33 = 328 pC/N, Kp = 0.63, Qm = 2300 were obtained when Cr2O3 was 0.6 wt.%, which exhibited more excellent piezoelectric properties than other compositions such as those with z = 0.2 wt.%, 0.4 wt.%, and 0.8 wt.%, but had a similar value as compared with the tmdoped samples. When the Cr2O3 additive increased, the Curie temperature moved toward low temperature and the changes of resonant frequency changed from positive to negative with increasing temperature.展开更多
The oxidation resistance behavior of SmCo(2:17)-type high-temperature magnets modified with Ni-Cr two-layer coating was studied. The study depicts the mass gain kinetics and magnetic properties of uncoated and NiCr-mo...The oxidation resistance behavior of SmCo(2:17)-type high-temperature magnets modified with Ni-Cr two-layer coating was studied. The study depicts the mass gain kinetics and magnetic properties of uncoated and NiCr-modified magnets oxidized at high temperature(500 ℃) in air for 200 h. The oxidation test results illustrate that the mass gain of uncoated magnet is6.95 mg·cm^(-2) which is more than that(0.08 mg·cm^(-2)) of coated magnet after 200 h. For the magnetic properties concerned, there is a great loss for uncoated magnet, while for coated magnet, magnetic properties do not change much. The study of uncoated magnet through X-ray diffraction(XRD) and electron probe microanalysis(EPMA) shows that the invasion of oxygen at high temperature leads to the loss of magnetic properties by changing the microstructure of magnet.展开更多
The flourishing development of emerging electromechanical applications has stimulated an urgent demand for ferroelectric ceramics with high piezoelectric properties and broad temperature usage range.However,it remains...The flourishing development of emerging electromechanical applications has stimulated an urgent demand for ferroelectric ceramics with high piezoelectric properties and broad temperature usage range.However,it remains a challenge to simultaneously obtain good piezoelectricity and reliable temperature stability in lead zirconate titanate(PZT)-based piezoelectric ceramics.To solve this issue,a synergetic strategy was proposed to introduce lead vacancies through niobium doping and construct morphotropic phase boundary(MPB).In this work,Pb_(0.905)Ba_(0.085)(V Pb″)_(0.01)[(Zr_(x)Ti_(1-x))_(0.98)Nb_(0.02)]O_(3)(PBZTN-x)material system was designed.Good comprehensive properties(d_(33)=864 pC/N,k_(p)=84%,T_(C)=201℃)and excellent temperature stability(less than 10%variation of electrical properties from 20℃ to 160℃)were obtained in PBZTN-0.540 ceramics.Good piezoelectricity can be attributed to high extrinsic contribution(domain wall motion)induced by Pb^(2+)vacancies and the existence of nano-domains emerged at MPB,while excellent temperature stability is mainly attributed to the minimized local stress in the lattice and the stable domain structure.展开更多
The poor structural stability and capacity retention of the high-voltage spinel-type LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)limits their further application.Herein,Al and Co were doped in LNMO materials for a more stable struct...The poor structural stability and capacity retention of the high-voltage spinel-type LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)limits their further application.Herein,Al and Co were doped in LNMO materials for a more stable structure and capacity.The LNMO,LiNi_(0.45)Al_(0.05)Mn_(1.5)O_(4)(LNAMO)and LiNi_(0.45)Co_(0.05)Mn_(1.5)O_(4)(LNCMO)were synthesized by calcination at 900℃ for 8 h,which was called as solid-phase method and applied universally in industry.XRD,FT-IR and CV test results showed the synthesized samples have cation disordering Fd-3m space group structures.Moreover,the incorporation of Al and Co increased the cation disordering of LNMO,thereby increasing the transfer rate of Li+.The SEM results showed that the doped samples performed more regular and ortho-octahedral.The EDS elemental analysis confirmed the uniform distribution of each metal element in the samples.Moreover,the doped samples showed better electrochemical properties than undoped LNMO.The LNAMO and LNCMO samples were discharged with specific capacities of 116.3 mA·h·g^(-1)and 122.8 mA·h·g^(-1)at 1 C charge/discharge rate with good capacity retention of 95.8% and 94.8% after 200 cycles at room temperature,respectively.The capacity fading phenomenon of the doped samples at 50℃ and 1 C rate was significantly improved.Further,cations doping also enhanced the rate performance,especially for the LNCMO,the discharge specific capacity of 117.9 mA·h·g^(-1)can be obtained at a rate of 5 C.展开更多
High-power capacitors are highly demanded in advanced electronics and power systems,where rising concerns on the operating temperatures have evoked the attention on developing highly reliable high-temperature dielectr...High-power capacitors are highly demanded in advanced electronics and power systems,where rising concerns on the operating temperatures have evoked the attention on developing highly reliable high-temperature dielectric polymers.Herein,polyetherimide(PEI)filled with highly insulating Al_(2)O_(3)(AO)nanoparticles dielectric composite films have been fabricated aiming for high thermal stability and reliability operated under high cycling electric field and elevated temperature.At room temperature,incorporating a small fraction of 0.5 vol%AO nanoparticles gives rise to a highest discharged energy density(U_(e))of 5.57 J·cm^(-3)and efficiency(η)of 90.9%at650 MV·m^(-1),and a robust cycling stability up to 10^(7) cycles at 400 MV·m^(-1).Due to the substantially reduced dielectric loss,2.0 vol%AO/PEI nanocomposite film exhibits excellent high-temperature capacitive performances,delivering U_(e)~7.33 J·cm^(-3)withη~88.8%under 700 MV·m^(-1),and cycling stability up to 10^(6) cycles under 400 MV·m^(-1)at 100℃,and U_(e)~5.57 J·cm^(-3)withη~84.7%under 620 MV·m^(-1)at 150℃.Molecular dynamic simulations are performed to understand the microscopic mechanism via revealing the polymer relaxation process in the AO/PEI composite at elevated temperatures.Our results are therefore very encouraging for high-temperature high-power capacitor application.展开更多
Polycrystalline samples of Lal-x（Srl-yAgy）x MnO3 （y = 0.0, 0.2, 0.4, 0.6, 1.0） were prepared by the solid-state reaction method. The temperature stability of magnetoresistance and magnetoresistance enhancement in ...Polycrystalline samples of Lal-x（Srl-yAgy）x MnO3 （y = 0.0, 0.2, 0.4, 0.6, 1.0） were prepared by the solid-state reaction method. The temperature stability of magnetoresistance and magnetoresistance enhancement in Lal_x（Srl_yAgy）~MnO3 system with both univalent and bivalent elements doped at A site and with unchanged value of Mn~＋/Mn4＋ ratio were explored through the measurements of X-ray diffraction patterns, magnetiza- tion-temperature （M-T） curves, resistivity-temperature （p-T） curves and magnetoresistance-temperature （MR-T） curves. The results are as follows： there are two peaks in the p-T curves of the samples with Ag doping, one is caused by resistance change during the paramagnetism- ferromagnetism transition, and the other is from boundary- dependent scattering of conduction electrons on the boundaries of grains. The peak value of MR increases with increasing Ag doping content, and it increases from 8.2 % for y ---- 0.2 to 29.6 % for y ---- 1.0 under the magnetic field of B = 0.8 T; MR remains a constant of 12 % in the temperature range of 218-168 K for the sample with y = 1.0, and the temperature stability of MR is in favor of the practical application of MR.展开更多
In this study, finite element analysis based on an Ansoft Maxwell software was used to reveal the temperature stability of a magnet ring and the equivalent structural periodic permanent-magnet（PPM） focusing system. ...In this study, finite element analysis based on an Ansoft Maxwell software was used to reveal the temperature stability of a magnet ring and the equivalent structural periodic permanent-magnet（PPM） focusing system. It is found that with the temperature increasing, the decrease rate of magnetic induction peak（Bz）maxof single magnet ring is greater than that of remanence Brof magnet in the range from room temperature to 200 °C, however,the PPM focusing system do have the same temperature characteristics of permanent-magnet materials. It indicates that the magnetic temperature properties of the PPM system can be effectively controlled by adjusting the temperature properties of the magnets. Moreover, the higher permeability of the magnets indicates the less Hcb, giving rise to lower magnetic induction peak （Bz）′max： Finally, it should be noted that the magnetic orientation deviation angle θ（／15°） of permanent magnets has little effect on the focusing magnetic field of the PPM system at different temperatures and the temperature stability. The obtained results are beneficial to the design and selection of permanent magnets for PPM focusing system.展开更多
The temperature stability of supercapacitor（SC） is largely determined by the properties of the electrolyte.Hydrogel electrolytes（HGE）, due to their hydrophilic polymer skeleton, show different temperature stabilit...The temperature stability of supercapacitor（SC） is largely determined by the properties of the electrolyte.Hydrogel electrolytes（HGE）, due to their hydrophilic polymer skeleton, show different temperature stability to that of liquid aqueous electrolytes. In this study, symmetric activated carbon（AC） SCs had been assembled with in situ electrodeposited poly（vinyl alcohol） potassium borate（PVAPB） HGE. The electrochemical performance of the SCs was systematically studied at different temperatures. Results show that the conductivity of PVAPB HGE is comparable with that of liquid aqueous electrolytes at different temperatures. The operating temperature range of PVAPB HGE SCs is -5–60°C, while those of the 1 mol/L Na2SO4SCs and the 0.9 mol/L KClSCs are 20–80°C and 20–40°C, respectively. The specific capacitance of PVAPB HGE SC is higher than those of SCs using liquid aqueous electrolytes at any temperature. The excellent temperature stability of PVAPB HGE makes it possible to build stable aqueous SCs in the wider temperature range.展开更多
High temperature self-propagating synthesis （SHS） process is very rapid, the reaction process becomes un-controlled after the SHS reaction is ignited. So the initial reaction conditions will have great effects on ph...High temperature self-propagating synthesis （SHS） process is very rapid, the reaction process becomes un-controlled after the SHS reaction is ignited. So the initial reaction conditions will have great effects on phase compositions and microstructures of reaction products. In this paper, the effects of the proportioning amount of Mg on the yield ratio and particle sizes of CeB6 were studied. The SHS reaction products and leached products were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results indicated that the SHS products consisted of MgO, CeB6 and little Mg3B206. The single CeB6 phase was contained after the SHS reaction products were leached. The purity of CeB6 was higher than 99.0 mass%, and the minimum particle sizes of CeB6 were within 30-70 nm. When the propor- tioning amount of Mg was 25% more than the theoretic amount, the yield of CeB6 was 68.68%. The antioxidant ability of CeB6 was rather stronger, which was oxidized step by step, and the initial oxidation temperature was 750 ℃ which indicated that it had good high temperature stability. The apparent activation energies of oxidation reactions of CeB6 were 200.09 and 312.10 kJ/mol, respectively, and reaction orders were 0.69 and 0.40, respectively.展开更多
Temperature stability and toughness of magnets are very important properties especially for application in motor. In this paper, it is found that temperature stability and toughness of magnets are improved when Fe is ...Temperature stability and toughness of magnets are very important properties especially for application in motor. In this paper, it is found that temperature stability and toughness of magnets are improved when Fe is substituted with Co and heavy rare earth is substituted for Nd in part and suitable rich B grain-boundary phase is added. In addition, heavy rare earth substitution decreases the remanence temperature coefficient greatly, but has a little effect on Curie temperature of the magnets, which is beneficial to Nd-Fe-B magnets for the application in motor.展开更多
(Bi_(0.5)Na_(0.5))TiO_(3)-based materials have attracted widespread attention due to large electro-strain,large remnant polarization(P r)and high Curie temperature(T C),but the existence of inherent depolarization tem...(Bi_(0.5)Na_(0.5))TiO_(3)-based materials have attracted widespread attention due to large electro-strain,large remnant polarization(P r)and high Curie temperature(T C),but the existence of inherent depolarization temperature(T d)limits the temperature stability and application temperature range.In this work,we find that K/Na ratio can regulate T d(from 90℃to 246℃)of the ceramics,which confirms that the increase of K substitution can effectively improve the temperature stability of the material.The phase structure and electrical properties of Bi_(0.5)(Na_(1-x)K_(x))_(0.5)TiO_(3)(BNKT x)ceramics can be well modulated by changing K/Na.In addition,BNKT x system exhibits excellent piezoelectric response at morphotropic phase boundary(MPB)of 20%BKT content(d_(33)=180 pC/N),where rhombohedral(R 3 c)phase and tetragonal(P 4 bm)phase coexist in MPB.With K further substitution,BNKT x ceramics transform into tetragonal phase,and the domain size grows due to the structural transition from short-range-correlated P 4 bm to long-range-correlated P 4 mm.The deferment of T d is also tightly related to the increase of P 4 mm/P 4 bm ratio.This work can provide an effective way to tailor depolarization temperature and electrical properties of BNT-based ceramics.展开更多
(1-x)(K(0.495)Na(0.495)La(0.01))(Nb(0.997)Cu(0.0075))O3-xBi(Mg(0.5)Zr(0.5))O3(abbreviated as KNLNC-xBMZ) ceramics were designed and prepared.The phase transition,microstructure and electrical properties of the ceramic...(1-x)(K(0.495)Na(0.495)La(0.01))(Nb(0.997)Cu(0.0075))O3-xBi(Mg(0.5)Zr(0.5))O3(abbreviated as KNLNC-xBMZ) ceramics were designed and prepared.The phase transition,microstructure and electrical properties of the ceramics were investigated.The phase structures of the ceramics transform from orthorhombic to pseudocubic phases and the grain sizes decrease gradually with BMZ content(x) increasing.Additionally,BMZ additions can significantly enhance the dielectric temperature stability and decrease the dielectric loss of ceramics over a relatively broad temperature range.KNLNC-0.02 BMZ ceramics exhibit high dielectric permittivity(εr=1542) and small variation(Δεr/ε(r150℃)≤±15%)in dielectric permittivity from 100 to 375℃,and low dielectric loss(tanδ≤2%) in the temperature range of 100-350℃,which suggests that this ceramic is a candidate for high-temperature capacitor application.展开更多
The coupling efficiency of hollow-core fiber changes with temperature,which leads to the decrease of the finesse(F)of fiber resonator and limits the performance of the resonant fiber optic gyroscope(R-FOG)system.Negat...The coupling efficiency of hollow-core fiber changes with temperature,which leads to the decrease of the finesse(F)of fiber resonator and limits the performance of the resonant fiber optic gyroscope(R-FOG)system.Negative-curvature antiresonant fiber(ARF)can maintain single-mode characteristics under the condition of large mode field diameter,achieve efficient and stable fiber coupling,and significantly improve the consistency of the F of the spatial coupling resonator in variable temperature environment.A new type of ARF with a mode field diameter(MFD)of 25μm is used to fabricate a fiber resonator with a length of 5.14 m.In the range of 25℃-75℃,the average F is 31.45.The ARF resonator is used to construct an R-FOG system that shows long-term bias stability(3600 s)of3.1°/h at room temperature,4.6°/h at 75℃.To our knowledge,this is the best reported index of hollow-core fiber resonator and R-FOG system within the temperature variation range of 50℃ test.展开更多
The chemical stability of simulated waste forms Zr_（1–x）Nd_xSiO_（4–x/2） was investigated using the static leach test（MCC-1） with lixiviants of three pH values（pH=4, 6.7 and 10） at three temperature points（4...The chemical stability of simulated waste forms Zr_（1–x）Nd_xSiO_（4–x/2） was investigated using the static leach test（MCC-1） with lixiviants of three pH values（pH=4, 6.7 and 10） at three temperature points（40, 90 and 150 oC） for periods ranging from 1 to 42 d, and the influence of temperature, pH, as well as their combined effects were explored in detail. The results showed that all the normalized release rate of Nd firstly decreased with leaching time and closed to equilibrium after 14 d. As the temperature increased, the normalized release rate of Nd also increased, but it was no more than 3×10^（–5） g/（m^2·d）. And, the normalized release rate of Nd reached the highest values（~5×10^（–5） g/（m^2·d）） when pH=4, whilst the normalized release rate of Nd remained the lowest value（~1×10^（–5） g/（m^2·d）） near neutral environment（pH=6.7）.展开更多
基金financially supported by National Key R&D Program of China(2022YFB2404903)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0400201)+6 种基金International Partnership Program of Chinese Academy of Sciences(121421KYSB20210028)National Natural Science Foundation of China(22209179,22478379)Liaoning Provincial Natural Science Foundation(2023-MS-010)Science and Technology Major Project of Liaoning Province(2024JH1/11700011)International Science and Technology Cooperation program of Liaoning(2023JH2/10700002)Liaoning Bidding for Key Technology Project(2022JH1/10800038,2023JH1/10400065)Liaoning Binhai Laboratory Funding(LBLA-2022-02,LBLB-2023-01)。
文摘Vanadium flow batteries(VFB)offer an ideal solution to the issue of storing massive amounts of electricity produced from intermittent renewables.However,the historical challenge of high thermal precipitation of V_(2)O_(5)from VO_(2)^(+)(~50℃for 1 day)represents a critical concern.Temperature control can alleviate the problem to a certain extent,however,at the expense of the cost of system design and operation.Herein,we report stable electrolyte chemistry at high temperature.By introducing Cr^(3+)as a stabilizer,it bridges with VO_(2)^(+)to form a Cr—O—V^(Ⅴ)structure,which reduces the electron cloud density of V.Therefore,it combines more tightly with H_(2)O and prevents its dehydration process.In addition,the dimerization process of VO_(2)^(+)is also inhibited due to the occupancy of Cr^(3+).As a result,a formed 1.5 M VO_(2)^(+)electrolyte demonstrates a high stability for over 30 days at 50℃(v.s.blank for<1 day at 50℃).Additionally,the low-temperature precipitation temperature of V^(2+)on the negative side has been reduced from 0℃of commercial electrolytes to-5℃.As a proof of concept,a VFB assembled with Nafion 115 membrane demonstrates an energy efficiency(EE)of 80%at 120 mA cm^(-2)for 1000 cycles(50℃).Most importantly,a 4 kW stack can continuously run for~1000 cycles with EE of 80%at 120 mA cm^(-2)without any heat management.Combined with high thermal stability and excellent performance,our design will certainly provide new impetus for the further commercialization of VFB batteries.
基金Project supported by the National Natural Science Foundation of China(21962021)the Yunnan Fundamental Research Projects(202001AU070121)+1 种基金the National Natural Science Foundation of China(51908091)the Special Basic Cooperative Research Programs of Yunnan Provincial Undergraduate Universities'Association(202101BA070001-084)。
文摘In order to analyze the influence of the addition of yttrium and manganese on the soot combustion performance and high temperature stability of CeO_(2) catalyst,a series of Y/Mn-modified CeO_(2) catalysts were prepared.The effects of structural properties,textural properties,oxygen vacancies,Ce^(3+),surface adsorbed oxygen species,reduction properties and desorption properties of oxygen species on the activity were analyzed by various characterization methods.The results of the activity test show that the addition of manganese is beneficial to enhancement of the activity,while the addition of yttrium increases the amount of reactive oxygen species,but decreases the activity.After aging at 700℃,the activity of the CeMn catalyst decreases most sharply,while the catalytic activity of the CeY catalyst can be maintained to a certain extent.Interestingly,the addition of yttrium and manganese at the same time can stabilize the activity.The fundamental reason is that yttrium and manganese move to the surface of the solid solution after aging,which increases the reduction performance of the catalyst,thus contributing to the increase of activity.Although the activity of CeYMn catalyst decreases after aging at 800℃,it is still higher than that of other catalysts aged at 700℃.
基金supported by the National Key Re-search and Development Program of China(No.2022YFB3807402)the National Natural Science Foundation of China(Nos.U23A20567,12204327,52061130216,52032007,and 52002252)+1 种基金the Fundamental Research Funds for the Central Universities(No.YJ2021154)the Natural Science Foundation of Sichuan Province(No.2023NSFSC0967).
文摘The rapid growth of new electromechanical applications has increased the demand for ferroelectric ce-ramics with excellent piezoelectric properties and a wide temperature operating range.However,achiev-ing robust piezoelectricity and temperature stability simultaneously in lead zirconate titanate(Pb(Zr,Ti)O_(3))based piezoelectric ceramics poses a significant challenge.This study proposes a new material system of 0.98Pb_(0.84)Ba_(0.16)(Zr_(2/3)Ti_(1/3))O_(3)-0.02Pb(Sb_(1/2)Nb_(1/2))O_(3)+x wt.%Sm_(2)O_(3)(PBZT-PSN-x Sm)to address this challenge.Remarkably,the ceramics x=0.4 demonstrate excellent piezoelectric properties(includ-ing piezoelectric coefficient d33 of 610 pC/N and Curie temperature TC of 290℃)and favorable tem-perature stability(i.e.,d33 varies less than 10%within 25-200℃).The high piezoelectric properties arise from the optimized phase fraction between rhombohedral(R)and tetragonal(T)phases and the increased grain size,which enhance the lattice distortion and the domain switching under electric fields,respectively.The superior temperature stability can be attributed to stable crystal structure and domain structure.These findings indicate that PBZT-PSN-x Sm ceramics hold great promise for practical utilization in high-temperature transducers and sensors.
基金Project supported by the National Natural Science Foundation of China(51102021)the Ministry of Science and Technology of China(2014CB643801,2011AA03A101)the Beijing Nova Program(2012099)
文摘The novel nitride-based luminescent materials have received much attention since the end of the last century. In this paper, the commercial Eu2＋-activated nitride red phosphors, Sr1.95Si5N8：Eu0.05, Sr1.85Si5N8：Eu0.15 and Ca0.99AlSiN3：Eu0.01 phosphors were an-nealed at different temperatures （beyond 300 oC） to investigate the dependence of their luminescence performance and structure vari-ability on the temperature. By photoluminescence spectra, X-ray diffraction （XRD） and thermogravimetry-differential scanning calo-rimetry （TG-DSC） analysis, the high temperature stability of the hosts and activator of the three samples were disclosed. With the an-nealing temperature increasing, the activator Eu2＋ions were firstly oxidized and then host in Sr1.95Si5N8：Eu0.05 and Sr1.85Si5N8：Eu0.15, but for Ca0.99AlSiN3：Eu0.01, only the oxidation of the host could be observed, which would lead to the luminescence degradation and even failure of these phosphors. The activator Eu2＋ions were much more stable in CaAlSiN3：Eu than Sr2Si5N8：Eu due to their crystal surroundings, and its concentration also influenced the temperature stability of Sr2Si5N8：Eu.
基金supported by the National Natural Foundation of China (No. 19934003)the Natural Science Research Key Program of Anhui Educational Committee (No. KJ2011A259)+2 种基金the Cultivating Base of Anhui Key Laboratory of Spintronics and Nano-materials Research Program(No. 2010YKF01No. 2010YKF04)the Professors’ and Doctors’ Research Startup Foundation of Suzhou University (Nos. 2011jb01 and 2011jb02)
文摘A series of the samples La_(1-x)(Sr_(1-y)Na_y)_xMnO_3(y=0.0,0.2,0.4,0.6,0.8,1.0) were prepared by the solid-state reaction method.Magnetoresistance enhancement and temperature stability of magnetoresistance in the system La_(1-x)(Sr_(1-y)Na_y)_xMnO_3 with unchanged Mn^(3+)/Mn^(4+) ratio through the doping of both monovalent and divalent elements at A site were studied through the measurements of X-ray diffraction(XRD) patterns,resistivity-temperature(ρ-T) curves and magnetoresistance-temperature(MR-T) curves.The results indicate that with the increase of Na doping amount,the peak value of MR increases,and it increases from 12.4% for y=0.2 to 50.6% for y=1.0 in the magnetic field B=0.8 T;ρ-T curves exhibit the double-peak phenomenon,which comes from the competition between the resistivity of surface phase and that of body phase;for the sample of y=0.8,MR increases slowly from 8.3% to 9.4% in the temperature range from 259 to 179 K,and MR is so stable in such a wide temperature range,which provides reference for the research on the temperature stability of MR.
基金This work was financially supported by the National Natural Science Foundation of China(No.52172118).
文摘In this work,a novel high entropy perovskite oxide(1-x)(Na_(0.2)Bi_(0.2)Ba_(0.2)Sr_(0.2)Ca_(0.2))TiO_(3-x)NaNbO_(3)(abbrevi-ated as(1-x)NBBSCT-x NN,x=0,0.05,0.1,0.15,and 0.2)was designed to improve temperature dielectric stability and energy storage performance by combining relaxor and antiferroelectric characteristics.The optimal composition of x=0.2 exhibits a high energy storage density of 3.51 J/cm^(3),together with wide temperature stable stability(■<15%,-70 to 110℃),excellent frequency stability(W rec andηvary by only±2.1%and±5.2%within the range of 1-600 Hz)and fast discharge rate(t_(0.9)=55.2 ns).This is mainly due to the enhancement of relaxation behavior and increase of E b caused by the decrease of grain size.These results offer a new strategy for designing high entropy ceramic materials of high performance in the future.
文摘The ceramics with Pb1.04Zr0.52Ti0.48O3 ＋ z wt.% Cr2O3 were prepared using the traditional technique. The effects of Cr2O3 doping on the phase structure, the microstructure, and the electrical properties of ceramics were investigated. Meanwhile, the temperature stabilities of the resonant frequency （fx） were studied. The results showed that the △fr/fr,25℃ decreased with the addition of 0.2 wt.% - 0.8 wt.% Cr2O3 as compared with the undoped samples. The minimum value （-0.182%） of △fr/fr,25℃ was obtained for z = 0.6 wt.% Cr2O3 samples that sintered at 1260℃. The values of ε^τ33/ε0 = 1650, tanδ = 0.006, d33 = 328 pC/N, Kp = 0.63, Qm = 2300 were obtained when Cr2O3 was 0.6 wt.%, which exhibited more excellent piezoelectric properties than other compositions such as those with z = 0.2 wt.%, 0.4 wt.%, and 0.8 wt.%, but had a similar value as compared with the tmdoped samples. When the Cr2O3 additive increased, the Curie temperature moved toward low temperature and the changes of resonant frequency changed from positive to negative with increasing temperature.
基金financially supported by the National Science Foundation of China(No.51471016)the Natural Science Foundation of Beijing(No.2151002)
文摘The oxidation resistance behavior of SmCo(2:17)-type high-temperature magnets modified with Ni-Cr two-layer coating was studied. The study depicts the mass gain kinetics and magnetic properties of uncoated and NiCr-modified magnets oxidized at high temperature(500 ℃) in air for 200 h. The oxidation test results illustrate that the mass gain of uncoated magnet is6.95 mg·cm^(-2) which is more than that(0.08 mg·cm^(-2)) of coated magnet after 200 h. For the magnetic properties concerned, there is a great loss for uncoated magnet, while for coated magnet, magnetic properties do not change much. The study of uncoated magnet through X-ray diffraction(XRD) and electron probe microanalysis(EPMA) shows that the invasion of oxygen at high temperature leads to the loss of magnetic properties by changing the microstructure of magnet.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.52002252 and 52032007).
文摘The flourishing development of emerging electromechanical applications has stimulated an urgent demand for ferroelectric ceramics with high piezoelectric properties and broad temperature usage range.However,it remains a challenge to simultaneously obtain good piezoelectricity and reliable temperature stability in lead zirconate titanate(PZT)-based piezoelectric ceramics.To solve this issue,a synergetic strategy was proposed to introduce lead vacancies through niobium doping and construct morphotropic phase boundary(MPB).In this work,Pb_(0.905)Ba_(0.085)(V Pb″)_(0.01)[(Zr_(x)Ti_(1-x))_(0.98)Nb_(0.02)]O_(3)(PBZTN-x)material system was designed.Good comprehensive properties(d_(33)=864 pC/N,k_(p)=84%,T_(C)=201℃)and excellent temperature stability(less than 10%variation of electrical properties from 20℃ to 160℃)were obtained in PBZTN-0.540 ceramics.Good piezoelectricity can be attributed to high extrinsic contribution(domain wall motion)induced by Pb^(2+)vacancies and the existence of nano-domains emerged at MPB,while excellent temperature stability is mainly attributed to the minimized local stress in the lattice and the stable domain structure.
基金supported by the National Natural Science Foundation of China(52022109 and 51834008)Beijing Municipal Natural Science Foundation(2202047)+1 种基金National Key Research and Development Program of China(2021YFC2901100)Science Foundation of China University of Petroleum,Beijing(2462021QNX2010,2462020YXZZ019,2462020YXZZ016,and 2462022QZDX008)。
文摘The poor structural stability and capacity retention of the high-voltage spinel-type LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)limits their further application.Herein,Al and Co were doped in LNMO materials for a more stable structure and capacity.The LNMO,LiNi_(0.45)Al_(0.05)Mn_(1.5)O_(4)(LNAMO)and LiNi_(0.45)Co_(0.05)Mn_(1.5)O_(4)(LNCMO)were synthesized by calcination at 900℃ for 8 h,which was called as solid-phase method and applied universally in industry.XRD,FT-IR and CV test results showed the synthesized samples have cation disordering Fd-3m space group structures.Moreover,the incorporation of Al and Co increased the cation disordering of LNMO,thereby increasing the transfer rate of Li+.The SEM results showed that the doped samples performed more regular and ortho-octahedral.The EDS elemental analysis confirmed the uniform distribution of each metal element in the samples.Moreover,the doped samples showed better electrochemical properties than undoped LNMO.The LNAMO and LNCMO samples were discharged with specific capacities of 116.3 mA·h·g^(-1)and 122.8 mA·h·g^(-1)at 1 C charge/discharge rate with good capacity retention of 95.8% and 94.8% after 200 cycles at room temperature,respectively.The capacity fading phenomenon of the doped samples at 50℃ and 1 C rate was significantly improved.Further,cations doping also enhanced the rate performance,especially for the LNCMO,the discharge specific capacity of 117.9 mA·h·g^(-1)can be obtained at a rate of 5 C.
基金financially supported by the National Natural Science Foundation of China (Nos.92066203 and51872009)the Fundamental Research Funds for the Central Universities。
文摘High-power capacitors are highly demanded in advanced electronics and power systems,where rising concerns on the operating temperatures have evoked the attention on developing highly reliable high-temperature dielectric polymers.Herein,polyetherimide(PEI)filled with highly insulating Al_(2)O_(3)(AO)nanoparticles dielectric composite films have been fabricated aiming for high thermal stability and reliability operated under high cycling electric field and elevated temperature.At room temperature,incorporating a small fraction of 0.5 vol%AO nanoparticles gives rise to a highest discharged energy density(U_(e))of 5.57 J·cm^(-3)and efficiency(η)of 90.9%at650 MV·m^(-1),and a robust cycling stability up to 10^(7) cycles at 400 MV·m^(-1).Due to the substantially reduced dielectric loss,2.0 vol%AO/PEI nanocomposite film exhibits excellent high-temperature capacitive performances,delivering U_(e)~7.33 J·cm^(-3)withη~88.8%under 700 MV·m^(-1),and cycling stability up to 10^(6) cycles under 400 MV·m^(-1)at 100℃,and U_(e)~5.57 J·cm^(-3)withη~84.7%under 620 MV·m^(-1)at 150℃.Molecular dynamic simulations are performed to understand the microscopic mechanism via revealing the polymer relaxation process in the AO/PEI composite at elevated temperatures.Our results are therefore very encouraging for high-temperature high-power capacitor application.
基金financially supported by the National Natural Science Foundation of China(NSFC)(No.19934003)the Key Program of Natural Science Foundation of Anhui Province(No.KJ2011A259)+1 种基金the Program of Professors and Doctors'Research Startup Foundation of Suzhou College(Nos.2011jb01 and 2011jb02)the Cultivating Base of Anhui Key Laboratory of Spintronics and Nano-materials Research Program(No.2010YKF04)
文摘Polycrystalline samples of Lal-x（Srl-yAgy）x MnO3 （y = 0.0, 0.2, 0.4, 0.6, 1.0） were prepared by the solid-state reaction method. The temperature stability of magnetoresistance and magnetoresistance enhancement in Lal_x（Srl_yAgy）~MnO3 system with both univalent and bivalent elements doped at A site and with unchanged value of Mn~＋/Mn4＋ ratio were explored through the measurements of X-ray diffraction patterns, magnetiza- tion-temperature （M-T） curves, resistivity-temperature （p-T） curves and magnetoresistance-temperature （MR-T） curves. The results are as follows： there are two peaks in the p-T curves of the samples with Ag doping, one is caused by resistance change during the paramagnetism- ferromagnetism transition, and the other is from boundary- dependent scattering of conduction electrons on the boundaries of grains. The peak value of MR increases with increasing Ag doping content, and it increases from 8.2 % for y ---- 0.2 to 29.6 % for y ---- 1.0 under the magnetic field of B = 0.8 T; MR remains a constant of 12 % in the temperature range of 218-168 K for the sample with y = 1.0, and the temperature stability of MR is in favor of the practical application of MR.
基金financially supported by the National Natural Science Foundation of China (No. 61001120)
文摘In this study, finite element analysis based on an Ansoft Maxwell software was used to reveal the temperature stability of a magnet ring and the equivalent structural periodic permanent-magnet（PPM） focusing system. It is found that with the temperature increasing, the decrease rate of magnetic induction peak（Bz）maxof single magnet ring is greater than that of remanence Brof magnet in the range from room temperature to 200 °C, however,the PPM focusing system do have the same temperature characteristics of permanent-magnet materials. It indicates that the magnetic temperature properties of the PPM system can be effectively controlled by adjusting the temperature properties of the magnets. Moreover, the higher permeability of the magnets indicates the less Hcb, giving rise to lower magnetic induction peak （Bz）′max： Finally, it should be noted that the magnetic orientation deviation angle θ（／15°） of permanent magnets has little effect on the focusing magnetic field of the PPM system at different temperatures and the temperature stability. The obtained results are beneficial to the design and selection of permanent magnets for PPM focusing system.
文摘The temperature stability of supercapacitor（SC） is largely determined by the properties of the electrolyte.Hydrogel electrolytes（HGE）, due to their hydrophilic polymer skeleton, show different temperature stability to that of liquid aqueous electrolytes. In this study, symmetric activated carbon（AC） SCs had been assembled with in situ electrodeposited poly（vinyl alcohol） potassium borate（PVAPB） HGE. The electrochemical performance of the SCs was systematically studied at different temperatures. Results show that the conductivity of PVAPB HGE is comparable with that of liquid aqueous electrolytes at different temperatures. The operating temperature range of PVAPB HGE SCs is -5–60°C, while those of the 1 mol/L Na2SO4SCs and the 0.9 mol/L KClSCs are 20–80°C and 20–40°C, respectively. The specific capacitance of PVAPB HGE SC is higher than those of SCs using liquid aqueous electrolytes at any temperature. The excellent temperature stability of PVAPB HGE makes it possible to build stable aqueous SCs in the wider temperature range.
基金supported by National Natural Science Foundation of China (51002025)National High Technology Research and Development Program of China(863 Program) (2010AA03A405)National Science and Technology Support Plan of China during the 12th Five-Year Plan (2012BAE01B02)
文摘High temperature self-propagating synthesis （SHS） process is very rapid, the reaction process becomes un-controlled after the SHS reaction is ignited. So the initial reaction conditions will have great effects on phase compositions and microstructures of reaction products. In this paper, the effects of the proportioning amount of Mg on the yield ratio and particle sizes of CeB6 were studied. The SHS reaction products and leached products were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results indicated that the SHS products consisted of MgO, CeB6 and little Mg3B206. The single CeB6 phase was contained after the SHS reaction products were leached. The purity of CeB6 was higher than 99.0 mass%, and the minimum particle sizes of CeB6 were within 30-70 nm. When the propor- tioning amount of Mg was 25% more than the theoretic amount, the yield of CeB6 was 68.68%. The antioxidant ability of CeB6 was rather stronger, which was oxidized step by step, and the initial oxidation temperature was 750 ℃ which indicated that it had good high temperature stability. The apparent activation energies of oxidation reactions of CeB6 were 200.09 and 312.10 kJ/mol, respectively, and reaction orders were 0.69 and 0.40, respectively.
基金This work was financially supported by the National Natural Science Foundation of China (No.50371019) and Beijing Municipal Science & Technology Committee Key Project (No.D0406002000091).
文摘Temperature stability and toughness of magnets are very important properties especially for application in motor. In this paper, it is found that temperature stability and toughness of magnets are improved when Fe is substituted with Co and heavy rare earth is substituted for Nd in part and suitable rich B grain-boundary phase is added. In addition, heavy rare earth substitution decreases the remanence temperature coefficient greatly, but has a little effect on Curie temperature of the magnets, which is beneficial to Nd-Fe-B magnets for the application in motor.
基金the support of the National Science Foundation of China (No. 51972215)the National Natural Science Foundation of China (NSFC) (No. 52061130216)+1 种基金a Newton Advanced Fellowship award (NAFR1201126)the Central Funds Guiding the Local Science and Technology Development of Sichuan Province(2021ZYD0022)
文摘(Bi_(0.5)Na_(0.5))TiO_(3)-based materials have attracted widespread attention due to large electro-strain,large remnant polarization(P r)and high Curie temperature(T C),but the existence of inherent depolarization temperature(T d)limits the temperature stability and application temperature range.In this work,we find that K/Na ratio can regulate T d(from 90℃to 246℃)of the ceramics,which confirms that the increase of K substitution can effectively improve the temperature stability of the material.The phase structure and electrical properties of Bi_(0.5)(Na_(1-x)K_(x))_(0.5)TiO_(3)(BNKT x)ceramics can be well modulated by changing K/Na.In addition,BNKT x system exhibits excellent piezoelectric response at morphotropic phase boundary(MPB)of 20%BKT content(d_(33)=180 pC/N),where rhombohedral(R 3 c)phase and tetragonal(P 4 bm)phase coexist in MPB.With K further substitution,BNKT x ceramics transform into tetragonal phase,and the domain size grows due to the structural transition from short-range-correlated P 4 bm to long-range-correlated P 4 mm.The deferment of T d is also tightly related to the increase of P 4 mm/P 4 bm ratio.This work can provide an effective way to tailor depolarization temperature and electrical properties of BNT-based ceramics.
基金financially supported by the National Natural Science Foundation of China(No.21501007)the Industrial Science and Technology Plan in Shaanxi Province of China (No.2016GY-226)+1 种基金the Doctoral Scientific Research Starting Foundation of Baoji University of Arts and Sciences (No.ZK15044)the Undergraduate Training Programs for Innovation and Entrepreneurship (No.201610721039)
文摘(1-x)(K(0.495)Na(0.495)La(0.01))(Nb(0.997)Cu(0.0075))O3-xBi(Mg(0.5)Zr(0.5))O3(abbreviated as KNLNC-xBMZ) ceramics were designed and prepared.The phase transition,microstructure and electrical properties of the ceramics were investigated.The phase structures of the ceramics transform from orthorhombic to pseudocubic phases and the grain sizes decrease gradually with BMZ content(x) increasing.Additionally,BMZ additions can significantly enhance the dielectric temperature stability and decrease the dielectric loss of ceramics over a relatively broad temperature range.KNLNC-0.02 BMZ ceramics exhibit high dielectric permittivity(εr=1542) and small variation(Δεr/ε(r150℃)≤±15%)in dielectric permittivity from 100 to 375℃,and low dielectric loss(tanδ≤2%) in the temperature range of 100-350℃,which suggests that this ceramic is a candidate for high-temperature capacitor application.
基金supported by the National Natural Science Foundation of China(61973019)。
文摘The coupling efficiency of hollow-core fiber changes with temperature,which leads to the decrease of the finesse(F)of fiber resonator and limits the performance of the resonant fiber optic gyroscope(R-FOG)system.Negative-curvature antiresonant fiber(ARF)can maintain single-mode characteristics under the condition of large mode field diameter,achieve efficient and stable fiber coupling,and significantly improve the consistency of the F of the spatial coupling resonator in variable temperature environment.A new type of ARF with a mode field diameter(MFD)of 25μm is used to fabricate a fiber resonator with a length of 5.14 m.In the range of 25℃-75℃,the average F is 31.45.The ARF resonator is used to construct an R-FOG system that shows long-term bias stability(3600 s)of3.1°/h at room temperature,4.6°/h at 75℃.To our knowledge,this is the best reported index of hollow-core fiber resonator and R-FOG system within the temperature variation range of 50℃ test.
基金Project supported by the National Natural Science Foundation of China(41302028,41302029,21507105)Thousand Youth Talents Plan(Y42H831301)+3 种基金Key Project of Sichuan Education Department(14ZA0099,15ZB0116)Foundation of Laboratory of National Defense Key Discipline for Nuclear Waste and Environmental Safety,Southwest University of Science and Technology(15yyhk10)the Doctor Foundation in Southwest University of Science and Technology(10zx7126)Hebei Science and Technology Support Program(15211121)
文摘The chemical stability of simulated waste forms Zr_（1–x）Nd_xSiO_（4–x/2） was investigated using the static leach test（MCC-1） with lixiviants of three pH values（pH=4, 6.7 and 10） at three temperature points（40, 90 and 150 oC） for periods ranging from 1 to 42 d, and the influence of temperature, pH, as well as their combined effects were explored in detail. The results showed that all the normalized release rate of Nd firstly decreased with leaching time and closed to equilibrium after 14 d. As the temperature increased, the normalized release rate of Nd also increased, but it was no more than 3×10^（–5） g/（m^2·d）. And, the normalized release rate of Nd reached the highest values（~5×10^（–5） g/（m^2·d）） when pH=4, whilst the normalized release rate of Nd remained the lowest value（~1×10^（–5） g/（m^2·d）） near neutral environment（pH=6.7）.
