Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shape...Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shaped ceramic cores.In this study,silica-based ceramic cores incorporating nano-3YSZ(3mol.% yttria stabilised zirconia)and micron-sized Y_(2)O_(3) were prepared via SL 3D printing ceramic technology to promote the formation of cristobalite and ZrSiO_(4),thereby improving the high-temperature properties.The flexural strength at 25℃ and 1,500℃,deflection at 1,500℃,shrinkage rate,and porosity of the core samples sintered at different temperatures(1,170℃,1,185℃,1,200℃,1,215℃,and 1,230℃)were tested and investigated.The mechanism underlying the high temperature performance of the cores was elucidated through analysis of cross-sectional morphology,element distribution,and phase constitution of the samples.As the sintering temperature increases,the shrinkage and flexural strength at 25℃ of the core rise,while the open porosity and deflection at 1,500℃ decrease.When the sintering temperature reaches 1,200℃ or higher,the 1,500℃ flexural strength can be measured,which increases as the sintering temperature rises.The core exhibits excellent creep resistance when sintered at temperatures of 1,200℃ and above.Considering the comprehensive performance requirements for the core,the sintering temperature of 1,200℃ was selected.At the sintering temperature of 1,200℃,the core exhibits shrinkage rates of 3.76%(X),3.38%(Y),and 3.95%(Z),alongside a flexural strength of 9.01 MPa at 25℃ and 32.15 MPa at 1,500℃,and an open porosity of 26.39%.The deflection of the core at 1,500℃ is 0.15 mm,which helps to maintain the dimensional stability of the ceramic core during casting.XRD results indicate that samples fractured after 25℃ flexural strength test still contain amorphous quartz glass,alongside substantial quantities of yttria stabilized zirconia and Y_(2)O_(3).Samples fractured after 1,500℃ flexural strength test exhibit significant crystallisation of amorphous quartz glass into cristobalite,with silica and 3YSZ combining to form ZrSiO_(4).Y_(2)O_(3) as a network modifier of the glass network destroys the bridging oxygen in the silica-oxygen bond,thereby reducing the energy required for glass crystallisation and promoting the crystallisation reaction of quartz glass to form cristobalite.In addition,nano-3YSZ combines with SiO_(2) at high temperatures to form ZrSiO_(4).Since cristobalite and ZrSiO_(4) are crystals,both of them have strong creep resistance,thus improving the high temperature flexural strength and deformation resistance of the ceramic cores.展开更多
To improve the low-temperature performances of Li-ion cells, three types of linear carboxylic ester-based electrolyte, such as EC/EMC/EA（1：1：2, mass ratio）, EC/EMC/EP（1：1：2, mass ratio） and EC/EMC/EB（1：1：2,...To improve the low-temperature performances of Li-ion cells, three types of linear carboxylic ester-based electrolyte, such as EC/EMC/EA（1：1：2, mass ratio）, EC/EMC/EP（1：1：2, mass ratio） and EC/EMC/EB（1：1：2, mass ratio）, were prepared to substitute for industrial electrolyte（EC/EMC/DMC）. Then, 18650-type Li Mn2O4-graphite cells（nominal capacity of 1150 mA ·h） were assembled and studied. Results show that the cells containing three types of electrolyte are able to undertake 5C discharging current with above 93% capacity retention at-20 °C. Electrochemical impedance spectra show that the discharge capacity fading of Li-ion cells at low temperature is mainly ascribed to the charge transfer resistance increasing with temperature decreasing. In comparison, the cells containing electrolyte of 1.0 mol/L LiPF6 in EC/EMC/EA（1：1：2, mass ratio） have the highest capacity retention of 90% at-40 °C and 44.41% at-60 °C, due to its lowest charge-transfer resistance.展开更多
Using a Hamburg wheel-track test device, the resistance to rutting of Gussasphalt is tested and compared. Gussasphalt with hard bitumen has good resistance to rutting. The related resistance abilities to cracking at ...Using a Hamburg wheel-track test device, the resistance to rutting of Gussasphalt is tested and compared. Gussasphalt with hard bitumen has good resistance to rutting. The related resistance abilities to cracking at low temperature of Gussasphalt are tested and compared through flexural experiments and the composite structure fatigue test with temperature dropping. Gussasphalt with high performance polymer modified bitumen has a longer fatigue life and a lower breaking temperature; they can be used in the future surfaces for steel bridge decks in Germany.展开更多
To evaluate the effects of solar greenhouse with different structure and CO2 enrichment on illumination and temperature performance of greenhouse and cucumber growth and development in the central region of Inner Mong...To evaluate the effects of solar greenhouse with different structure and CO2 enrichment on illumination and temperature performance of greenhouse and cucumber growth and development in the central region of Inner Mongolia, the research used traditional solar greenhouse （A） and blanket-inside solar greenhouse（B）, and set 4 treatments： AE （traditional solar greenhouse A with CO2 enrichment）, AN （traditional solar greenhouse A without CO2 enrichment）, BE （blanket-inside solar greenhouse B with CO2 enrichment） and BN （blanket-inside solar greenhouse B without CO2 enrichment）, to explore the influence of cucumber growth, photosynthetic property, quality and yield in different structure solar greenhouses with CO2 enrichment. The results showed that the illumination and temperature in blanket-inside solar greenhouse was superior to traditional solar greenhouse, and the average light intensity in blanket-inside solar greenhouse increased by 21.05%, compared with traditional solar greenhouse. Under the condition of same greenhouse structure, stem height ,average stem diameter, contents of soluble sugar, vitamin C, net photosynthetic rate and yield showed any significant difference between the treatments with CO2 enrichment or not. Under the condition of same CO2 concentration, BE cucumber average stem height, average stem diameter, contents of soluble sugar, net photosynthetic rate and yield in BE was higher than which in AE. Therefore, the optimization in structure of blanket-inside solar greenhouse remarkably improved illumination and temperature property, combining with CO2 enrichment as application technology, there was crucial significance to promote the greenhouse performance and improve the efficiency of greenhouse vegetable production.展开更多
Effects of flaky rare earth oxide additives including Er2O3,Tm2O3,and Yb2O3,Lu2O3 on high temperature and high rate discharge performance of nickel electrodes were investigated.The discharge efficiency at 0.2C reached...Effects of flaky rare earth oxide additives including Er2O3,Tm2O3,and Yb2O3,Lu2O3 on high temperature and high rate discharge performance of nickel electrodes were investigated.The discharge efficiency at 0.2C reached 96% at 60 oC for electrodes with 1 at.% flaky rare earth oxides.The high rate discharge performance for electrodes with flaky rare earth oxides were improved significantly,for example,discharge efficiency at 5C improved from 50% to 70%.The results showed that the end charging potential of the ...展开更多
The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatur...The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.展开更多
A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accurac...A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is proposed.This sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion coefficients.In experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS sensor.The experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,respectively.In addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature repeatability.Furthermore,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was improved.The proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.展开更多
Low temperature cracking has become one of the important factors that diminish asphalt pavement's ride quality and service life.Especially in cold region,cracking caused by low temperature is the main distress for...Low temperature cracking has become one of the important factors that diminish asphalt pavement's ride quality and service life.Especially in cold region,cracking caused by low temperature is the main distress form.This paper discussed the effect of aggregate gradation on the low temperature performance in asphalt paving mixtures.A total of 11 asphalt mixtures with 11 different aggregate gradations and one asphalt binder content were studied.Volumetric properties of the coarse aggregate and asphalt mixtures showed aggregate grading has a significant impact on the degree of aggregate interlock in asphalt mixtures.A trend is existed in the low temperature performance with the change of gradation.With the aid of mathematic statistics,it indicates gradation affects the low temperature performance significantly.The findings also indicate the relationship between the degree of aggregate interlock in asphalt mixtures and the low temperature performance:With the stone-to-stone contact developed,the mixture has a high energy to resist contract and deformation at low temperature.The properties of fine aggregate and asphalt play an important part in resisting low temperature cracking in floating structure.But it provides lower energy to resist low temperature cracking compared to the skeleton structure.展开更多
Evaluation of high temperature performance of SBS-modified asphalt mixture was presented.Both wheel loaded method and creep method were adopted for two different mixtures and two kinds of specimens with different heig...Evaluation of high temperature performance of SBS-modified asphalt mixture was presented.Both wheel loaded method and creep method were adopted for two different mixtures and two kinds of specimens with different height,and corresponding indicators were measured.Meanwhile,the correlation between these indicators was thoroughly analyzed and two kinds of mixtures were compared.The experimental results show that there is a good linear relationship between LWT indicators and CT indicators for M-13,while a relatively poor relationship for M-25,especially that between dynamic stiffness and static stiffness and that between dynamic stability and static creep stiffness.Besides,logarithmic relationship between DS and RD has a higher determination coefficient than that for linear relationship.Thus,multi-index evaluation should be taken for synthetically assessing high temperature performance of asphalt mixture.展开更多
This work develops 2-Phenyl-1H-imidazole-1-sulfonate(PHIS)as a multi-functional electrolyte additive for H2O/HF scavenging and film formation to improve the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_...This work develops 2-Phenyl-1H-imidazole-1-sulfonate(PHIS)as a multi-functional electrolyte additive for H2O/HF scavenging and film formation to improve the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/graphite batteries.After 450 cycles at room temperature(25℃),the discharge capacity retentions of batteries with blank and PHIS-containing electrolyte are 56.03%and 94.92%respectively.After 230 cycles at high temperatures(45℃),their values are 75.30%and 88.38%respectively.The enhanced electrochemical performance of the batteries with PHIS-containing electrolyte is supported by the spectroscopic characterization and theoretical calculations.It is demonstrated that this PHIS electrolyte additive can facilitate the construction of the electrode interface films,remove the H2O/HF in the electrolyte,and improve the electrochemical performance of the batteries.This work not only develops a sulfonate-based electrolyte but also can stimulate new ideas of functional additives to improve the battery performance.展开更多
Drilling fluid additives has a major impact on rheology behavior and other performances of the drilling fluid.The key to low temperature drilling fluids is choosing antifreeze and polymer agent which have a strong abi...Drilling fluid additives has a major impact on rheology behavior and other performances of the drilling fluid.The key to low temperature drilling fluids is choosing antifreeze and polymer agent which have a strong ability in resisting low temperature.On the basis of determining glycol as antifreeze agent,the low-temperature-performance and capacities of anti-collapse of regular validity mud agents have been studied,the mechanism of anti-caving of the partially hydrolyzed polyacrylamide(PHPA),polypropylene potassium(KPA) and PAC-141 polymer additives have been also analyzed.A pilot study of compatibility between ethylene glycol and the polymers has educed that the polymers,ethylene glycol and inorganic salt are compatible,and they can significantly reduce the freezing point of drilling fluid.Anti-collapse ability of the drilling mud is the results of synergistic action among the agents.展开更多
Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are commo...Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are common and particularly problematic with LaCrO_(3) heaters,which can experience significant power fluctuations and even failure due to substantial resistance changes—an issue conventional thyristorcontrolled heating systems cannot effectively manage.To address this limitation,we have developed the Multi-Anvil Stable Temperature controller(MASTer),a high-performance heating system optimized for MAP experiments.MASTer enables precise,high-speed measurement of heating parameters and power output control,incorporating a gentle regulation strategy to enhance stability.It ensures consistent heating across various heater types,including LaCrO_(3),with power fluctuations limited to±0.1 W and temperature fluctuations to within±2℃ in most cases.The design,operating principles,user interface,functionality,and performance of the heating system are discussed in detail.展开更多
Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrins...Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrinsic polysulfides shuttle resulting from their concentration gradient diffusion and sluggish conversion kinetics but also serious safety issue caused by thermolabile and combustible polymer separators.Herein, it is presented for the first time that a robust and multifunctional separator with urchin-like Co-doped Fe OOH microspheres and multiwalled carbon nanotubes(MWCNTs) as an interlayer simultaneously achieves to suppress polysulfides shuttle as well as improves thermotolerance and nonflammability of commercial PP separator. Accordingly, Li-S batteries with modified separator exhibit remarkable performance in a wide range temperatures of-25–100 ℃. Typically, under 25 ℃, ultrahigh initial capacities of 1441 and 827.29 m A h g-1 at 1 C and 2 C are delivered, and remained capacities of 936 and 663.18 mA h g-1 can be obtained after 500 cycles, respectively. At 0.1 C, the S utilization can reach up to 97%. Significantly, at 1 C, the batteries also deliver an excellent performance with remained capacities of high to862.3, 608.4 and 420.6 m A h g-1 after 100, 300 and 450 cycles under 75, 0 and-25 ℃, respectively. This work provides a new insight for developing stable and safe high-performance Li-S batteries.展开更多
The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytica...The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics.展开更多
Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-te...Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-temperature-efficiency of nickel electrode, spherical nickel hydroxide mixed with various ratios of Lu2O3 was used as active material of pasted nickel electrodes. The results of charge/discharge experiments, cyclic voltammetric measurements and XRD characterizations have shown that after addition of Lu2O3, the oxygen evolution overpotcntial is elevated much, the charge efficiency of nickel electrode at high temperature is greatly improved and the content of β-NiOOH phase increases in charged electrodes. In addition, the mixed ratio of Lu2O3 has different effects on high temperature performances of nickel electrode at different charge/discharge currents, 3.5 % is the optimum mixed ratio, and the action of Lu2O3 on high temperature electrochemical behaviors is more apparent when nickel electrodes are charged at small current than large current.展开更多
he thermal performance test of the horizontal coaxial double tube hot gas duct (HGD) with an internal thermal insulation for the 10MW High Temperature Reactor Test Module (HTR10) was conducted on a Helium Test Loop(HE...he thermal performance test of the horizontal coaxial double tube hot gas duct (HGD) with an internal thermal insulation for the 10MW High Temperature Reactor Test Module (HTR10) was conducted on a Helium Test Loop(HETL). The present paper deals with the technical feature of the HETL, the test section and the thermal performance test of the HGD. The HGD test section with a triple tube structure includes an inner heater, a HGD model and a coldhot gas mixer. A counterflow of cold and hot helium gas under the pressure of about 3.0 MPa and the minimum temperature of 100℃ in the annular passage and the maximum of 950℃ in the central tube of the HGD model was formed. The HGD model was undergone 20 times of pressure cycle test under the pressure ranging from 0.1 to 3.4 MPa, 18 times of the temperature cycle test under the temperature ranging from 100 to 950℃ and high temperature (700 to 950℃) helium flow test for a period of more than 350 hours. The effective thermal conductivity (λeff) of the internal insulation of the HGD was investigated experimentally. The relationship of the effective thermal conductivity with the average tmperature of the internal insulation layer is λeff(W/m/℃)=0.3512+0.0003T(℃). The test results indicate that the HGD model has good abilities to resist heat flux from the central tube to the annular passage, temperature variations, and pressure variations.展开更多
Solid-state lithium batteries are constrained by sluggish ion kinetics and poor interfacial stability.Herein,a quasi-solid polymer electrolyte was designed via an in-situ copolymerization strategy with 1,3-dioxolane(D...Solid-state lithium batteries are constrained by sluggish ion kinetics and poor interfacial stability.Herein,a quasi-solid polymer electrolyte was designed via an in-situ copolymerization strategy with 1,3-dioxolane(DOL)and 1,3,5-trioxane(TXE).The incorporation of TXE modulates the regularity and motility of the polymer segment and then enhances the Li^(+)transport kinetics.Moreover,fluorothylene carbonate and tris(trimethylsilyl)borate are conducive to constructing a stable and inorganic-rich electrodeelectrolyte interface,which can effectively prevent electrolyte decomposition and inhibit lithium dendrite growth.The two additives can also participate in solvation to form a loose solvated sheath that accelerates Li^(+)coupling-decoupling behaviors.When applied in Li‖LiFePO_(4)(LFP)battery,an initial capacity of 157.8 mAh g^(-1)and a capacity retention of 88.7%after 800 cycles at 1 C were obtained,along with an exceptional rate performance(114.3 mAh g^(-1),5 C).Even at-20℃,a remarkable capacity of103.7 mAh g^(-1)was still obtained.The synergetic strategy of ether-oxygen segment design and solvation structure regulation paves the way for high-performance quasi-solid lithium metal batteries.展开更多
To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO...To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO_(2)precursor solutions with mass fractions of 0,0.2%,0.5%,1.0%,and 3.0%;and Fe_(2)O_(3)-SiO_(2)composite aerogels were fabricated using CO_(2)supercritical drying technology.The effects of the Fe_(2)O_(3)extra addition on the aerogels were investigated.The results show that:(1)Fe_(2)O_(3)doping does not alter the aerogel morphology;Fe_(2)O_(3)suppresses the mass loss at high temperatures and enhances the high-temperature stability of the composite;(2)below 800℃,the aerogel with 0.5%Fe_(2)O_(3)exhibits the lowest thermal conductivity and the best thermal insulation performance;at 800-1000℃,the aerogel with 1%Fe_(2)O_(3)exhibits the lowest thermal conductivity and a good nanoporous structure;(3)by adjusting the Fe_(2)O_(3)extra addition,composite aerogels suitable for different temperature ranges can be tailored.展开更多
As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(etheny...As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(ethenyl)silyloxysilane (HVDS) with Si–O bonds and unsaturated bonds is introduced as additive designing functional electrolyte to enhance the long-cycle stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/graphite LIBs at elevated temperature.The preferential oxidization and component of HVDS facilitate the generation of an extremely robust and ultra-thin cathode electrolyte interphase (CEI) comprising a chemically bonded silane polymer.This interphase effectively suppresses side-reactions of electrolyte,mitigates HF erosion,and reduces irreversible phase transitions.Benefiting from the above merits,the batteries’capacity retention shows a remarkable increase from 20% to 92% after nearly 1550 cycles conducted at room temperature.And under elevated temperature conditions (45℃),the capacity retention remains 80%after 670 cycles,in comparison to a drop to 80%after only 250 cycles with the blank electrolyte.These findings highlight HVDS’s potential to functionalize the electrolyte,marking a breakthrough in improving the longevity and reliability of NCM811/graphite LIBs under challenging conditions.展开更多
The rapid development of electric vehicles demands the development of high performance nickel metal hydride battery that is able to endure high temperature. The discharge properties of Ti 0.7 Zr 0.5 V 0.2 Mn 1.8- x Ni...The rapid development of electric vehicles demands the development of high performance nickel metal hydride battery that is able to endure high temperature. The discharge properties of Ti 0.7 Zr 0.5 V 0.2 Mn 1.8- x Ni x ( x =0.4, 0.8, 1.1, 1.4, 1.7)hydrogen storage alloys was investigated and its phase composition was analyzed using X ray diffraction. The results show that the cycling life was improved as the content of nickel increases. When x =0.4, 0.8, 1.1 and 1.4, the main phase is MgZn 2 type C14 Laves phase and the second one is cubic TiNi phase. When x =1.7, the Laves phase structure disappears. EDAS analysis shows that the increase of nickel content is effective in suppressing the dissolution of vanadium component in alloys. [展开更多
基金financially supported by the Liaoning Province Science and Technology Plan Joint Program(2023JH2/101700037).
文摘Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shaped ceramic cores.In this study,silica-based ceramic cores incorporating nano-3YSZ(3mol.% yttria stabilised zirconia)and micron-sized Y_(2)O_(3) were prepared via SL 3D printing ceramic technology to promote the formation of cristobalite and ZrSiO_(4),thereby improving the high-temperature properties.The flexural strength at 25℃ and 1,500℃,deflection at 1,500℃,shrinkage rate,and porosity of the core samples sintered at different temperatures(1,170℃,1,185℃,1,200℃,1,215℃,and 1,230℃)were tested and investigated.The mechanism underlying the high temperature performance of the cores was elucidated through analysis of cross-sectional morphology,element distribution,and phase constitution of the samples.As the sintering temperature increases,the shrinkage and flexural strength at 25℃ of the core rise,while the open porosity and deflection at 1,500℃ decrease.When the sintering temperature reaches 1,200℃ or higher,the 1,500℃ flexural strength can be measured,which increases as the sintering temperature rises.The core exhibits excellent creep resistance when sintered at temperatures of 1,200℃ and above.Considering the comprehensive performance requirements for the core,the sintering temperature of 1,200℃ was selected.At the sintering temperature of 1,200℃,the core exhibits shrinkage rates of 3.76%(X),3.38%(Y),and 3.95%(Z),alongside a flexural strength of 9.01 MPa at 25℃ and 32.15 MPa at 1,500℃,and an open porosity of 26.39%.The deflection of the core at 1,500℃ is 0.15 mm,which helps to maintain the dimensional stability of the ceramic core during casting.XRD results indicate that samples fractured after 25℃ flexural strength test still contain amorphous quartz glass,alongside substantial quantities of yttria stabilized zirconia and Y_(2)O_(3).Samples fractured after 1,500℃ flexural strength test exhibit significant crystallisation of amorphous quartz glass into cristobalite,with silica and 3YSZ combining to form ZrSiO_(4).Y_(2)O_(3) as a network modifier of the glass network destroys the bridging oxygen in the silica-oxygen bond,thereby reducing the energy required for glass crystallisation and promoting the crystallisation reaction of quartz glass to form cristobalite.In addition,nano-3YSZ combines with SiO_(2) at high temperatures to form ZrSiO_(4).Since cristobalite and ZrSiO_(4) are crystals,both of them have strong creep resistance,thus improving the high temperature flexural strength and deformation resistance of the ceramic cores.
基金Project(2007BAE12B01)supported by the National Key Technology Research and Development Program of ChinaProject(20803095)supported by the National Natural Science Foundation of China
文摘To improve the low-temperature performances of Li-ion cells, three types of linear carboxylic ester-based electrolyte, such as EC/EMC/EA（1：1：2, mass ratio）, EC/EMC/EP（1：1：2, mass ratio） and EC/EMC/EB（1：1：2, mass ratio）, were prepared to substitute for industrial electrolyte（EC/EMC/DMC）. Then, 18650-type Li Mn2O4-graphite cells（nominal capacity of 1150 mA ·h） were assembled and studied. Results show that the cells containing three types of electrolyte are able to undertake 5C discharging current with above 93% capacity retention at-20 °C. Electrochemical impedance spectra show that the discharge capacity fading of Li-ion cells at low temperature is mainly ascribed to the charge transfer resistance increasing with temperature decreasing. In comparison, the cells containing electrolyte of 1.0 mol/L LiPF6 in EC/EMC/EA（1：1：2, mass ratio） have the highest capacity retention of 90% at-40 °C and 44.41% at-60 °C, due to its lowest charge-transfer resistance.
文摘Using a Hamburg wheel-track test device, the resistance to rutting of Gussasphalt is tested and compared. Gussasphalt with hard bitumen has good resistance to rutting. The related resistance abilities to cracking at low temperature of Gussasphalt are tested and compared through flexural experiments and the composite structure fatigue test with temperature dropping. Gussasphalt with high performance polymer modified bitumen has a longer fatigue life and a lower breaking temperature; they can be used in the future surfaces for steel bridge decks in Germany.
文摘To evaluate the effects of solar greenhouse with different structure and CO2 enrichment on illumination and temperature performance of greenhouse and cucumber growth and development in the central region of Inner Mongolia, the research used traditional solar greenhouse （A） and blanket-inside solar greenhouse（B）, and set 4 treatments： AE （traditional solar greenhouse A with CO2 enrichment）, AN （traditional solar greenhouse A without CO2 enrichment）, BE （blanket-inside solar greenhouse B with CO2 enrichment） and BN （blanket-inside solar greenhouse B without CO2 enrichment）, to explore the influence of cucumber growth, photosynthetic property, quality and yield in different structure solar greenhouses with CO2 enrichment. The results showed that the illumination and temperature in blanket-inside solar greenhouse was superior to traditional solar greenhouse, and the average light intensity in blanket-inside solar greenhouse increased by 21.05%, compared with traditional solar greenhouse. Under the condition of same greenhouse structure, stem height ,average stem diameter, contents of soluble sugar, vitamin C, net photosynthetic rate and yield showed any significant difference between the treatments with CO2 enrichment or not. Under the condition of same CO2 concentration, BE cucumber average stem height, average stem diameter, contents of soluble sugar, net photosynthetic rate and yield in BE was higher than which in AE. Therefore, the optimization in structure of blanket-inside solar greenhouse remarkably improved illumination and temperature property, combining with CO2 enrichment as application technology, there was crucial significance to promote the greenhouse performance and improve the efficiency of greenhouse vegetable production.
基金supported by the 863 National Research and Development Project Foundation of China (2006AA11A151)
文摘Effects of flaky rare earth oxide additives including Er2O3,Tm2O3,and Yb2O3,Lu2O3 on high temperature and high rate discharge performance of nickel electrodes were investigated.The discharge efficiency at 0.2C reached 96% at 60 oC for electrodes with 1 at.% flaky rare earth oxides.The high rate discharge performance for electrodes with flaky rare earth oxides were improved significantly,for example,discharge efficiency at 5C improved from 50% to 70%.The results showed that the end charging potential of the ...
文摘The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.
基金the National Natural Science Foundation of China(Nos.62075057 and 11975091)the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.21IRTSTHN011).
文摘A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is proposed.This sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion coefficients.In experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS sensor.The experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,respectively.In addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature repeatability.Furthermore,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was improved.The proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50778057)the Research Fund for the Doctoral Program of Higher Education(Grant No.20060213002)
文摘Low temperature cracking has become one of the important factors that diminish asphalt pavement's ride quality and service life.Especially in cold region,cracking caused by low temperature is the main distress form.This paper discussed the effect of aggregate gradation on the low temperature performance in asphalt paving mixtures.A total of 11 asphalt mixtures with 11 different aggregate gradations and one asphalt binder content were studied.Volumetric properties of the coarse aggregate and asphalt mixtures showed aggregate grading has a significant impact on the degree of aggregate interlock in asphalt mixtures.A trend is existed in the low temperature performance with the change of gradation.With the aid of mathematic statistics,it indicates gradation affects the low temperature performance significantly.The findings also indicate the relationship between the degree of aggregate interlock in asphalt mixtures and the low temperature performance:With the stone-to-stone contact developed,the mixture has a high energy to resist contract and deformation at low temperature.The properties of fine aggregate and asphalt play an important part in resisting low temperature cracking in floating structure.But it provides lower energy to resist low temperature cracking compared to the skeleton structure.
基金Funded by the National Natural Science Foundation of China (No.50868003)Guangxi Key Laboratory of Architecture Engineering’s Detecting and Testing (No.07109005-9)
文摘Evaluation of high temperature performance of SBS-modified asphalt mixture was presented.Both wheel loaded method and creep method were adopted for two different mixtures and two kinds of specimens with different height,and corresponding indicators were measured.Meanwhile,the correlation between these indicators was thoroughly analyzed and two kinds of mixtures were compared.The experimental results show that there is a good linear relationship between LWT indicators and CT indicators for M-13,while a relatively poor relationship for M-25,especially that between dynamic stiffness and static stiffness and that between dynamic stability and static creep stiffness.Besides,logarithmic relationship between DS and RD has a higher determination coefficient than that for linear relationship.Thus,multi-index evaluation should be taken for synthetically assessing high temperature performance of asphalt mixture.
基金financially supported by the Scientific and Technological Plan Projects of Guangzhou City(202103040001)。
文摘This work develops 2-Phenyl-1H-imidazole-1-sulfonate(PHIS)as a multi-functional electrolyte additive for H2O/HF scavenging and film formation to improve the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/graphite batteries.After 450 cycles at room temperature(25℃),the discharge capacity retentions of batteries with blank and PHIS-containing electrolyte are 56.03%and 94.92%respectively.After 230 cycles at high temperatures(45℃),their values are 75.30%and 88.38%respectively.The enhanced electrochemical performance of the batteries with PHIS-containing electrolyte is supported by the spectroscopic characterization and theoretical calculations.It is demonstrated that this PHIS electrolyte additive can facilitate the construction of the electrode interface films,remove the H2O/HF in the electrolyte,and improve the electrochemical performance of the batteries.This work not only develops a sulfonate-based electrolyte but also can stimulate new ideas of functional additives to improve the battery performance.
文摘Drilling fluid additives has a major impact on rheology behavior and other performances of the drilling fluid.The key to low temperature drilling fluids is choosing antifreeze and polymer agent which have a strong ability in resisting low temperature.On the basis of determining glycol as antifreeze agent,the low-temperature-performance and capacities of anti-collapse of regular validity mud agents have been studied,the mechanism of anti-caving of the partially hydrolyzed polyacrylamide(PHPA),polypropylene potassium(KPA) and PAC-141 polymer additives have been also analyzed.A pilot study of compatibility between ethylene glycol and the polymers has educed that the polymers,ethylene glycol and inorganic salt are compatible,and they can significantly reduce the freezing point of drilling fluid.Anti-collapse ability of the drilling mud is the results of synergistic action among the agents.
基金supported by the National Science Fund for Distinguished Young Scholars(Grant No.T2225027)the National Key R&D Program of China(Grant No.2023YFA1608902).
文摘Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are common and particularly problematic with LaCrO_(3) heaters,which can experience significant power fluctuations and even failure due to substantial resistance changes—an issue conventional thyristorcontrolled heating systems cannot effectively manage.To address this limitation,we have developed the Multi-Anvil Stable Temperature controller(MASTer),a high-performance heating system optimized for MAP experiments.MASTer enables precise,high-speed measurement of heating parameters and power output control,incorporating a gentle regulation strategy to enhance stability.It ensures consistent heating across various heater types,including LaCrO_(3),with power fluctuations limited to±0.1 W and temperature fluctuations to within±2℃ in most cases.The design,operating principles,user interface,functionality,and performance of the heating system are discussed in detail.
基金the National Natural Science Foundation of China(51773134)the Program for the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(51721091)+2 种基金the Sichuan Province Science and Technology Project(2019YFH0112)the Sichuan Province Youth Science and Technology Innovation Team(2017TD0006)the Fundamental Research Funds for the Central Universities(2017SCU04A14 and YJ201821)。
文摘Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrinsic polysulfides shuttle resulting from their concentration gradient diffusion and sluggish conversion kinetics but also serious safety issue caused by thermolabile and combustible polymer separators.Herein, it is presented for the first time that a robust and multifunctional separator with urchin-like Co-doped Fe OOH microspheres and multiwalled carbon nanotubes(MWCNTs) as an interlayer simultaneously achieves to suppress polysulfides shuttle as well as improves thermotolerance and nonflammability of commercial PP separator. Accordingly, Li-S batteries with modified separator exhibit remarkable performance in a wide range temperatures of-25–100 ℃. Typically, under 25 ℃, ultrahigh initial capacities of 1441 and 827.29 m A h g-1 at 1 C and 2 C are delivered, and remained capacities of 936 and 663.18 mA h g-1 can be obtained after 500 cycles, respectively. At 0.1 C, the S utilization can reach up to 97%. Significantly, at 1 C, the batteries also deliver an excellent performance with remained capacities of high to862.3, 608.4 and 420.6 m A h g-1 after 100, 300 and 450 cycles under 75, 0 and-25 ℃, respectively. This work provides a new insight for developing stable and safe high-performance Li-S batteries.
文摘The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics.
文摘Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-temperature-efficiency of nickel electrode, spherical nickel hydroxide mixed with various ratios of Lu2O3 was used as active material of pasted nickel electrodes. The results of charge/discharge experiments, cyclic voltammetric measurements and XRD characterizations have shown that after addition of Lu2O3, the oxygen evolution overpotcntial is elevated much, the charge efficiency of nickel electrode at high temperature is greatly improved and the content of β-NiOOH phase increases in charged electrodes. In addition, the mixed ratio of Lu2O3 has different effects on high temperature performances of nickel electrode at different charge/discharge currents, 3.5 % is the optimum mixed ratio, and the action of Lu2O3 on high temperature electrochemical behaviors is more apparent when nickel electrodes are charged at small current than large current.
文摘he thermal performance test of the horizontal coaxial double tube hot gas duct (HGD) with an internal thermal insulation for the 10MW High Temperature Reactor Test Module (HTR10) was conducted on a Helium Test Loop(HETL). The present paper deals with the technical feature of the HETL, the test section and the thermal performance test of the HGD. The HGD test section with a triple tube structure includes an inner heater, a HGD model and a coldhot gas mixer. A counterflow of cold and hot helium gas under the pressure of about 3.0 MPa and the minimum temperature of 100℃ in the annular passage and the maximum of 950℃ in the central tube of the HGD model was formed. The HGD model was undergone 20 times of pressure cycle test under the pressure ranging from 0.1 to 3.4 MPa, 18 times of the temperature cycle test under the temperature ranging from 100 to 950℃ and high temperature (700 to 950℃) helium flow test for a period of more than 350 hours. The effective thermal conductivity (λeff) of the internal insulation of the HGD was investigated experimentally. The relationship of the effective thermal conductivity with the average tmperature of the internal insulation layer is λeff(W/m/℃)=0.3512+0.0003T(℃). The test results indicate that the HGD model has good abilities to resist heat flux from the central tube to the annular passage, temperature variations, and pressure variations.
基金supported by the Fundamental Research Funds for the Central Universities(JD2311)the National Natural Science Foundation of China(Grant No.51572012)。
文摘Solid-state lithium batteries are constrained by sluggish ion kinetics and poor interfacial stability.Herein,a quasi-solid polymer electrolyte was designed via an in-situ copolymerization strategy with 1,3-dioxolane(DOL)and 1,3,5-trioxane(TXE).The incorporation of TXE modulates the regularity and motility of the polymer segment and then enhances the Li^(+)transport kinetics.Moreover,fluorothylene carbonate and tris(trimethylsilyl)borate are conducive to constructing a stable and inorganic-rich electrodeelectrolyte interface,which can effectively prevent electrolyte decomposition and inhibit lithium dendrite growth.The two additives can also participate in solvation to form a loose solvated sheath that accelerates Li^(+)coupling-decoupling behaviors.When applied in Li‖LiFePO_(4)(LFP)battery,an initial capacity of 157.8 mAh g^(-1)and a capacity retention of 88.7%after 800 cycles at 1 C were obtained,along with an exceptional rate performance(114.3 mAh g^(-1),5 C).Even at-20℃,a remarkable capacity of103.7 mAh g^(-1)was still obtained.The synergetic strategy of ether-oxygen segment design and solvation structure regulation paves the way for high-performance quasi-solid lithium metal batteries.
文摘To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO_(2)precursor solutions with mass fractions of 0,0.2%,0.5%,1.0%,and 3.0%;and Fe_(2)O_(3)-SiO_(2)composite aerogels were fabricated using CO_(2)supercritical drying technology.The effects of the Fe_(2)O_(3)extra addition on the aerogels were investigated.The results show that:(1)Fe_(2)O_(3)doping does not alter the aerogel morphology;Fe_(2)O_(3)suppresses the mass loss at high temperatures and enhances the high-temperature stability of the composite;(2)below 800℃,the aerogel with 0.5%Fe_(2)O_(3)exhibits the lowest thermal conductivity and the best thermal insulation performance;at 800-1000℃,the aerogel with 1%Fe_(2)O_(3)exhibits the lowest thermal conductivity and a good nanoporous structure;(3)by adjusting the Fe_(2)O_(3)extra addition,composite aerogels suitable for different temperature ranges can be tailored.
基金financially supported by the Scientific Research Innovation Project of Graduate School of South China Normal University (No. 2024KYLX081)。
文摘As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(ethenyl)silyloxysilane (HVDS) with Si–O bonds and unsaturated bonds is introduced as additive designing functional electrolyte to enhance the long-cycle stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/graphite LIBs at elevated temperature.The preferential oxidization and component of HVDS facilitate the generation of an extremely robust and ultra-thin cathode electrolyte interphase (CEI) comprising a chemically bonded silane polymer.This interphase effectively suppresses side-reactions of electrolyte,mitigates HF erosion,and reduces irreversible phase transitions.Benefiting from the above merits,the batteries’capacity retention shows a remarkable increase from 20% to 92% after nearly 1550 cycles conducted at room temperature.And under elevated temperature conditions (45℃),the capacity retention remains 80%after 670 cycles,in comparison to a drop to 80%after only 250 cycles with the blank electrolyte.These findings highlight HVDS’s potential to functionalize the electrolyte,marking a breakthrough in improving the longevity and reliability of NCM811/graphite LIBs under challenging conditions.
文摘The rapid development of electric vehicles demands the development of high performance nickel metal hydride battery that is able to endure high temperature. The discharge properties of Ti 0.7 Zr 0.5 V 0.2 Mn 1.8- x Ni x ( x =0.4, 0.8, 1.1, 1.4, 1.7)hydrogen storage alloys was investigated and its phase composition was analyzed using X ray diffraction. The results show that the cycling life was improved as the content of nickel increases. When x =0.4, 0.8, 1.1 and 1.4, the main phase is MgZn 2 type C14 Laves phase and the second one is cubic TiNi phase. When x =1.7, the Laves phase structure disappears. EDAS analysis shows that the increase of nickel content is effective in suppressing the dissolution of vanadium component in alloys. [
