Inspired by the demand of improving the riding comfort and meeting the lightweight design of the vehicle, an inerter-based X-structure nonlinear energy sink(IXNES) is proposed and applied in the half-vehicle system to...Inspired by the demand of improving the riding comfort and meeting the lightweight design of the vehicle, an inerter-based X-structure nonlinear energy sink(IXNES) is proposed and applied in the half-vehicle system to enhance the dynamic performance. The X-structure is used as a mechanism to realize the nonlinear stiffness characteristic of the NES, which can realize the flexibility, adjustability, high efficiency, and easy operation of nonlinear stiffness, and is convenient to apply in the vehicle suspension, and the inerter is applied to replacing the mass of the NES based on the mass amplification characteristic. The dynamic model of the half-vehicle system coupled with the IX-NES is established with the Lagrange theory, and the harmonic balance method(HBM) and the pseudo-arc-length method(PALM) are used to obtain the dynamic response under road harmonic excitation. The corresponding dynamic performance under road harmonic and random excitation is evaluated by six performance indices, and compared with that of the original half-vehicle system to show the benefits of the IX-NES. Furthermore, the structural parameters of the IX-NES are optimized with the genetic algorithm. The results show that for road harmonic and random excitation, using the IX-NES can greatly reduce the resonance peaks and root mean square(RMS) values of the front and rear suspension deflections and the front and rear dynamic tire loads, while the resonance peaks and RMS values of the vehicle body vertical and pitching accelerations are slightly larger.When the structural parameters of the IX-NES are optimized, the vehicle body vertical and pitching accelerations of the half-vehicle system could reduce by 2.41% and 1.16%,respectively, and the other dynamic performance indices are within the reasonable ranges.Thus, the IX-NES combines the advantages of the inerter, X-structure, and NES, which improves the dynamic performance of the half-vehicle system and provides an effective option for vibration attenuation in the vehicle engineering.展开更多
In this work, a simulated aircraft fuel tank inerting system has been successfully estab- lished based on a model tank. Experiments were conducted to investigate the influences of different operating parameters on the...In this work, a simulated aircraft fuel tank inerting system has been successfully estab- lished based on a model tank. Experiments were conducted to investigate the influences of different operating parameters on the inerting effectiveness of the system, including flow rate of the inert gas (nitrogen-enriched air), inert gas concentration, fuel load of the tank and different inerting approaches. The experimental results show that under the same operating conditions, the time span of a complete inerting process decreased as the flow rate of inert gas was increased; the time span using the inert gas with 5% oxygen concentration was much longer than that using pure nitrogen; when the fuel tank was inerted using the ullage washing approach, the time span increased as the fuel load was decreased; the ullage washing approach showed the best inerting performance when the time span of a complete inerting process was the evaluation criterion, but when the decrease of dissolved oxygen concentration in the fuel was also considered to characterize the inerting effective- ness, the approach of ullage washing and fuel scrubbing at the same time was the most effective.展开更多
The properties of aviation fuel have a great influence on the performance of oxygenconsuming inerting systems. Based on the establishment of the catalytic inerting process, the flow relationship of each gas component ...The properties of aviation fuel have a great influence on the performance of oxygenconsuming inerting systems. Based on the establishment of the catalytic inerting process, the flow relationship of each gas component flowing through the catalytic reactor was derived. The mathematical model of the gas concentration in the gas phase of the fuel tank was established based on the mass conservation equation, and the fuel tank model was verified by performing experiments.The results showed that the fuel type exerts a considerably higher influence on the performance of the oxygen-consuming inerting system compared to the corresponding influence on the hollow fiber membrane system, and the relative magnitude of the inerting rates of the four fuel types is RP5 > RP3 > RP6 > JP8. In addition, a higher catalytic efficiency or fuel load rate corresponds to a higher rate of decrease of the oxygen concentration in the gas phase, and the inerting time is inversely proportional to the suction flow rate of the fan. When different fuels are used, the amount of cooling gas and water released from the inerting system are different. Therefore, the influence of fuel type on the system performance should be extensively considered in the future.展开更多
Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combin...Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combinations between polymers and fillers is vital,but blind attempts are often made due to a lack of understanding of the mechanisms involved in the interaction between polymers and fillers.Herein,we employ in-situ polymerization to prepare a polymer based on an ether-nitrile copolymer with high cathode stability as the foundation and discuss the performance enhancement mechanisms of argyrodite and nano-alumina.With 1%content of sulfide interacting with the polymer at the two-phase interface,the local enhancement of lithium-ion migration capability can be achieved,avoiding the reduction in capacity due to the low ion conductivity of the passivation layer during cycling.The capacity retention after 50cycles at 0.5 C increases from 83.5%to 94.4%.Nano-alumina,through anchoring the anions and interface inhibition functions,eventually poses an initial discharge capacity of 136.8 m A h g^(-1)at 0.5 C and extends the cycling time to 1000 h without short-circuiting in lithium metal batteries.Through the combined action of dual fillers on the composite solid-state electrolyte,promising insights are provided for future material design.展开更多
In order to improve the seismic performance of adjacent buildings,two types of tuned inerter damper(TID)damping systems for adjacent buildings are proposed,which are composed of springs,inerter devices and dampers in ...In order to improve the seismic performance of adjacent buildings,two types of tuned inerter damper(TID)damping systems for adjacent buildings are proposed,which are composed of springs,inerter devices and dampers in serial or in parallel.The dynamic equations of TID adjacent building damping systems were derived,and the H2 norm criterion was used to optimize and adjust them,so that the system had the optimum damping performance under white noise random excitation.Taking TID frequency ratio and damping ratio as optimization parameters,the optimum analytical solutions of the displacement frequency response of the undamped structure under white noise excitation were obtained.The results showed that compared with the classic TMD,TID could obtain a better damping effect in the adjacent buildings.Comparing the TIDs composed of serial or parallel,it was found that the parallel TIDs had more significant advantages in controlling the peak displacement frequency response,while the H2 norm of the displacement frequency response of the damping system under the coupling of serial TID was smaller.Taking the adjacent building composed of two ten-story frame structures as an example,the displacement and energy collection time history analysis of the adjacent building coupled with the optimum design parameter TIDs were carried out.It was found that TID had a better damping effect in the full-time range compared with the classic TMD.This paper also studied the potential power of TID in adjacent buildings,which can be converted into available power resources during earthquakes.展开更多
1.Introduction Artificial intelligence(AI)is a rapidly growing field of technol-ogy,which“will enliven inert objects,much as electricity did more than a century ago.Everything that we formerly electrified will now co...1.Introduction Artificial intelligence(AI)is a rapidly growing field of technol-ogy,which“will enliven inert objects,much as electricity did more than a century ago.Everything that we formerly electrified will now cognitize”[1].AI advances are constantly pushing the frontier of what machines can do.Increased attention is being placed on AI research,as well as its development and deployment by commer-cial investors,defense strategists,and policy makers[2].展开更多
The thermal stresses relaxation of Ni/NiFe2O4 system functionally graded cermet inert anode for aluminum electrolysis was optimally designed. The transient thermal stresses of the inert anode under complex boundary co...The thermal stresses relaxation of Ni/NiFe2O4 system functionally graded cermet inert anode for aluminum electrolysis was optimally designed. The transient thermal stresses of the inert anode under complex boundary condition during high-temp (955℃) electrolysis were calculated using the finite-element software ANSYS, the influence of different parameters on the distribution of the thermal stresses were analyzed. The results showed that, during the process of thermal shock, the thermal hoop tensile stress on the surface of the anode is very large, which is possibly the major cause of anode crack; when the radius of the anode is between 0.05-0.15m, a range that can be realized by recent manufacturing technology, the optimum composition distribution exponent p is 0.25; The hoop tensile stresses reduce with the decrease of anode scale and also decrease with the decrease of the convection coefficient between the electrolyte and the anode.展开更多
When dealing with the oscillations of fixed-base structures or machines induced by external forces,suppressing the vibrational impact on the adjacent structures and the environment helps to maintain the structural dur...When dealing with the oscillations of fixed-base structures or machines induced by external forces,suppressing the vibrational impact on the adjacent structures and the environment helps to maintain the structural durability and ensure the users′comfort level.This study proposed an inerter-based optimal solution to suppress the vibrational forces and energy transmitted to the supporting ground by utilizing the great potential of the inerter.For the external force,which contains various frequency bands,the stochastic response and an energy balance analysis are conducted to evaluate the force transmissibility,structural displacement,and vibration power flow.Given the benefits of the inerter,a transmitted-force-based optimal design framework is proposed for inerter systems,of which the effectiveness is validated by numerical examples.The obtained results show that inerter systems are capable of providing significant reductions in the structural displacement and the force transmitted to the supporting ground.Particularly,the closed-form power equation indicated that a grounded inerter can suppress the force transmission and vibrational energy,thus leading to a less negative impact on the ground and environment.Revealing the working mechanism and optimal design strategy of the inerter can help solve the force-transmission control problem experienced by some practical structures.展开更多
In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamin...In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamine.This deep blue coordination compound is inert characteristically and remains stable in 1.7 mol/L sulfuric acid,2.4 mol/L hydrochloric or ni- tric acid.It will not be decomposed by masking agents even on boiled,while in that case,almost all the colored coordination com- pounds formed by other metal ions will be decomposed completely.This inert character of the coordination compound of molybdenum(Ⅵ) and its utilization in improving the analytical selectivity have been discussed.In the coexistence of various for- eign ions,especially in the presence of a great quantity of tungsten,which always interferes with the determination of molybdenum,the direct determination of molybdenum in the aqueous solution by applying this system has shown an acceptable sensitivity and reproducibility.From the results of determination in some synthetic and standard samples,it seems feasible to use this system in the determination of molybdenum in nonferrous alloys.展开更多
Inert gas-clustered systems (Xn, X = He, Ne, Ar and n = 2 - 20) were established in this study and their stability as a result of interparticulate interaction was examined. Ferric chloride and ferrous oxides were used...Inert gas-clustered systems (Xn, X = He, Ne, Ar and n = 2 - 20) were established in this study and their stability as a result of interparticulate interaction was examined. Ferric chloride and ferrous oxides were used as catalysts to promote reaction, and 5-nitro-1,2,4-triazol-3-one (NTO) was theoretically synthesized under an inert gas (X6)-clustered environment in this study. The raw material, urea, initially underwent chlorination using chlorine as the reagent, followed by amination, formylation and nitration. Reaction routes closely related to the experimental processes were successfully constructed, and the corresponding energy barriers were estimated for each elementary reaction. The findings revealed that the average errors in the B3LYP/6-31G(d, p)-calculated geometry and vibrational frequency of NTO in an Ne6 system relative to the observed values were 0.83% and 1.84%, respectively. The neon gas-clustered system achieved greater stabilization, which results from the difference in self-consistent field energy (ESCF), than the corresponding stabilization acquired in a helium- or argon-based system. Ferric chloride serves as a good catalyst to reduce the energy barrier of the chlorination reaction, and ferrous oxide is suitable for catalyzing the amination, formylation and nitration reactions, although nitric acid is the better agent for nitration. The catalytic Ne6-clustered reaction system is suggested to be a more feasible pathway for the synthesis of NTO.展开更多
A two-degree-of-freedom(2DOF)vibration isolation structure with an integrated geometric nonlinear inerter(NI)device is proposed.The device is integrated into an inertial nonlinear energy sink(INES),and its vibration s...A two-degree-of-freedom(2DOF)vibration isolation structure with an integrated geometric nonlinear inerter(NI)device is proposed.The device is integrated into an inertial nonlinear energy sink(INES),and its vibration suppression performance is examined by the Runge-Kutta(RK)method and verified by the harmonic balance method(HBM).The new isolator is compared with a traditional vibration isolator.The results show a significant improvement in the vibration suppression performance.To investigate the effects of the excitation amplitude and initial condition on the dynamics of the system,a series of transmissibility-frequency response analyses are performed based on the displacement transmissibility.The energy flow of the system is analyzed,and numerous calculations reveal a series of ideal values for the energy sink in the NI-INES system.This study provides new insights for the design of vibration isolators.展开更多
A novel implementation of negative stiffness elements(NSEs)is proposed,utilizing industrial grade nitrogen gas springs as pre-stressed stiffness elements in a configuration with lever arms.This NSE is combined with an...A novel implementation of negative stiffness elements(NSEs)is proposed,utilizing industrial grade nitrogen gas springs as pre-stressed stiffness elements in a configuration with lever arms.This NSE is combined with an inerter to form a stiff dynamic absorber(SDA)for vertical seismic protection of structures with base isolation.The SDA is optimized to minimize vertical accelerations while ensuring static structural integrity,excellent damping performance and containment of relative displacements.The introduction of gas springs in place of conventional linear springs addresses important practical limitations through features of non-linearity and industrial grade manufacturing.The proposed implementation is dimensioned for a 50-ton structure and evaluated numerically for 25 actual earthquake records,in comparison with a linear SDA model and an equivalent conventional damper(CD).Individual and averaged results of acceleration and displacement time histories demonstrate vastly superior response compared to CD regarding induced accelerations for similar displacements.Performance equivalency with the linear SDA model indicates the stability of the gas spring implementation while guaranteeing predictability,tested endurance,proper tolerances,and off-axis motion resistance without requiring additional guiding components,as opposed to conventional springs.These features render the proposed implementation a promising solution for the realization of NSEs in seismic protection.展开更多
To test the effectiveness of N_(2) and CO_(2) in preventing coal from spontaneously combusting,researchers used an adiabatic oxidation apparatus to conduct an experiment with different temperature starting points.Non-...To test the effectiveness of N_(2) and CO_(2) in preventing coal from spontaneously combusting,researchers used an adiabatic oxidation apparatus to conduct an experiment with different temperature starting points.Non-adsorbed helium(He)was used as a reference gas,and coal and oxygen concentration temperature variations were analyzed after inerting.The results showed that He had the best cooling effect,N_(2) was second,and CO_(2) was the worst.At 70℃and 110℃,the impact of different gases on reducing oxygen concentration and the cooling effect was the same.However,at the starting temperature of 150℃,CO_(2) was less effective in lowering oxygen concentration at the later stage than He and N_(2).N_(2) and CO_(2) can prolong the flame retardation time of inert gas and reduce oxygen displacement with an initial temperature increase.When the starting temperature is the same,N_(2) injection cools coal samples and replaces oxygen more effectively than CO_(2) injection.The flame retardancy of inert gas is the combined result of the cooling effect of inert gas and the replacement of oxygen.These findings are essential for using inert flame retardant technology in the goaf.展开更多
Development of practical lithium(Li)metal batteries(LMBs)remains challenging despite promises of Li metal anodes(LMAs),owing to Li dendrite formation and highly reactive surface nature.Polyolefin separators used in LM...Development of practical lithium(Li)metal batteries(LMBs)remains challenging despite promises of Li metal anodes(LMAs),owing to Li dendrite formation and highly reactive surface nature.Polyolefin separators used in LMBs may undergo severe mechanical and chemical deterioration when contacting with LMAs.To identify the best polyolefin separator for LMBs,this study investigated the separator-deterministic cycling stability of LMBs under practical conditions,and redefined the key influencing factors,including pore structure,mechanical stability,and chemical affinity,using 12 different commercial separators,including polyethylene(PE),polypropylene(PP),and coated separators.At extreme compression triggered by LMA swelling,isotropic stress release by balancing the machine direction and transverse direction tensile strengths was found to be crucial for mitigating cell short-circuiting.Instead of PP separators,a PE separator that possesses a high elastic modulus and a highly connected pore structure can uniformly regulate LMA swelling.The ceramic coating reinforced short-circuiting resistance,while the cycling efficiency degraded rapidly owing to the detrimental interactions between ceramics and LMAs.This study identified the design principle of separators for practical LMBs with respect to mechanical stability and chemical affinity toward LMAs by elucidating the impacts of separator modification on the cycling performance.展开更多
The cathode spots are a common phenomenon in the TIG(tungsten inert gas)welding process.However,it is rarely observed in the activating TIG welding process.This research is mainly focused on the effect of activating f...The cathode spots are a common phenomenon in the TIG(tungsten inert gas)welding process.However,it is rarely observed in the activating TIG welding process.This research is mainly focused on the effect of activating flux on cathode spots in the activating TIG welding.The characteristics and behaviors of cathode spots were investigated in activating TIG welding by the high-speed camera and the spectrograph.Three kinds of oxide(TiO_(2),SiO_(2),MnO_(2))and two halide(MnCl_(2),CaF_(2))activating fluxes are used in the activating TIG welding process.The results show that differ from the TIG welding,the oxide activating flux increases the number of cathode spots and decreases the velocity.The effect is the opposite for the halide activating flux.Moreover,the number of spots no longer varies with the current except TiO2 activating flux.As the temperature of the weld pool surface increases the spot moves away from the center.But this rule is not valid when silica and manganese compounds activating fluxes are used.The variation of cathode spots is caused by the oxide film reformed and the distribution of weld slag.The formation mechanism of cathode spots might be the impact of ions on the cathode surface and the strong electric field formed near the cathode surface.展开更多
Welding defects influence the desired properties of welded joints giving fabrication experts a common problem of not being able to produce weld structures with optimal strength and quality. In this study, the fuz...Welding defects influence the desired properties of welded joints giving fabrication experts a common problem of not being able to produce weld structures with optimal strength and quality. In this study, the fuzzy logic system was employed to predict welding tensile strength. 30 sets of welding experiments were conducted and tensile strength data was collected which were converted from crisp variables into fuzzy sets. The result showed that the fuzzy logic tool is a highly effective tool for predicting tensile strength present in TIG mild steel weld having a coefficient of determination value of 99%.展开更多
Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, t...Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, the process, weld combinations, laser-CMT hybrid welding and applications of CMT welding are critically reviewed. Microstructure and other weld characteristics have been discussed at length for various base metal combinations. Particularly, the welding of aluminium and steel with better results has been possible with CMT Welding. The results reviewed in this article indicate that the CMT-Laser hybrid welding is more preferable to Laser or Laser hybrid welding. CMT welding has found applications in automobile industries, defence sectors and power plants as a method of additive manufacturing.展开更多
Aging treatment and various heat input conditions and mechanical properties of TIG welded 606I-T6 alloy joints were adopted to investigate the microstructural evolution by microstructural observations, microhardness t...Aging treatment and various heat input conditions and mechanical properties of TIG welded 606I-T6 alloy joints were adopted to investigate the microstructural evolution by microstructural observations, microhardness tests, and tensile tests. With an increase in heat input, the width of the heat-affected zone (HAZ) increases and grains in the fusion zone (FZ) coarsen. Moreover, the hardness of the HAZ decreases, whereas that of the FZ decreases initially and then increases with an increase in heat input. Low heat input results in the low ultimate tensile strength of the welded joints due to the presence of partial penetrations and pores in the welded joints. After a simple artificial aging treatment at 175℃ for 8 h, the microstructure of the welded joints changes slightly. The mechanical properties of the welded joints enhance significantly after the aging process as few precipitates distribute in the welded seam.展开更多
Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2—12 Process parameters studied include pH, steady state temperature, concentration, and ...Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2—12 Process parameters studied include pH, steady state temperature, concentration, and the type of gases. Greater than 96% hydrolysis was observed in 30 minutes through this process and the rate of destruction increased with the help of more soluble and low thermal inert gas. So with Krypton, omethoate was found to undergo rapid destruction as compared with Argon. In the presence of ultrasound, the observed first order rate of hydrolysis of omethoate is found to be independent of pH. The formation of transient supercritical water(SCW) appears to be an important factor in the acceleration of chemical reactions in the presence of ultrasound. A detailed chemical reaction mechanism for omethoate destruction in water was formulated. Experimental results and theoretical kinetic mechanism demonstrated that the most of the omethoate undergo destruction inside the cavitating holes. A very less effect of temperature on the degradation of omethoate within a temperature range of 20—70℃ proves that a small quantity of omethoate undergoes secondary destruction in the bulk liquid.展开更多
Due to the serious greenhouse gas effects caused by the increasing concentration of atmospheric CO_2,carbon capture and storage(CCS) has been an important area of research and many technologies are developed within th...Due to the serious greenhouse gas effects caused by the increasing concentration of atmospheric CO_2,carbon capture and storage(CCS) has been an important area of research and many technologies are developed within this field. Molten salt CO_2 capture and electrochemical transformation(MSCC-ET) process is a desirable method due to a high CO_2 solubility, a wide potential window of molten salts and easily-controlled electrode reactions. Generally, electro-splitting CO_2 in molten salts begins with CO_2 absorption reactions to form CO_3^(2-), which is then followed by the carbon deposition at the cathode and O_2 evolution at the anode. As a result, CO_2 is electro-converted to O_2 and carbon with different morphologies, compositions, microstructures and functional properties. This report introduces the MSCC-ET process, summarizes the reactions occurring in the molten salts and at the electrode surfaces, as well as the morphological variations of the cathodic products. The inert anode materials, cost estimation and scale-up evaluation of the process are then discussed. It is presumed that with a comprehensive understanding of the electrode reactions during electrolysis and the functional properties of carbon materials obtained during CO_2 electro-splitting can provide a foundation for further developing this environmentally friendly process.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 12172153 and51805216)the China Postdoctoral Science Foundation (No. 2023M731668)the Major Project of Basic Science (Natural Science) of the Jiangsu Higher Education Institutions of China(No. 22KJA410001)。
文摘Inspired by the demand of improving the riding comfort and meeting the lightweight design of the vehicle, an inerter-based X-structure nonlinear energy sink(IXNES) is proposed and applied in the half-vehicle system to enhance the dynamic performance. The X-structure is used as a mechanism to realize the nonlinear stiffness characteristic of the NES, which can realize the flexibility, adjustability, high efficiency, and easy operation of nonlinear stiffness, and is convenient to apply in the vehicle suspension, and the inerter is applied to replacing the mass of the NES based on the mass amplification characteristic. The dynamic model of the half-vehicle system coupled with the IX-NES is established with the Lagrange theory, and the harmonic balance method(HBM) and the pseudo-arc-length method(PALM) are used to obtain the dynamic response under road harmonic excitation. The corresponding dynamic performance under road harmonic and random excitation is evaluated by six performance indices, and compared with that of the original half-vehicle system to show the benefits of the IX-NES. Furthermore, the structural parameters of the IX-NES are optimized with the genetic algorithm. The results show that for road harmonic and random excitation, using the IX-NES can greatly reduce the resonance peaks and root mean square(RMS) values of the front and rear suspension deflections and the front and rear dynamic tire loads, while the resonance peaks and RMS values of the vehicle body vertical and pitching accelerations are slightly larger.When the structural parameters of the IX-NES are optimized, the vehicle body vertical and pitching accelerations of the half-vehicle system could reduce by 2.41% and 1.16%,respectively, and the other dynamic performance indices are within the reasonable ranges.Thus, the IX-NES combines the advantages of the inerter, X-structure, and NES, which improves the dynamic performance of the half-vehicle system and provides an effective option for vibration attenuation in the vehicle engineering.
文摘In this work, a simulated aircraft fuel tank inerting system has been successfully estab- lished based on a model tank. Experiments were conducted to investigate the influences of different operating parameters on the inerting effectiveness of the system, including flow rate of the inert gas (nitrogen-enriched air), inert gas concentration, fuel load of the tank and different inerting approaches. The experimental results show that under the same operating conditions, the time span of a complete inerting process decreased as the flow rate of inert gas was increased; the time span using the inert gas with 5% oxygen concentration was much longer than that using pure nitrogen; when the fuel tank was inerted using the ullage washing approach, the time span increased as the fuel load was decreased; the ullage washing approach showed the best inerting performance when the time span of a complete inerting process was the evaluation criterion, but when the decrease of dissolved oxygen concentration in the fuel was also considered to characterize the inerting effective- ness, the approach of ullage washing and fuel scrubbing at the same time was the most effective.
基金supported by National Natural Science Foundation of China Civil Aviation Joint Fund (No.U1933121)Postgraduate Research & Practice Innovation Program of Jiangsu Province (No.KYCX19_0198)The Fundamental Research Funds for the Central Universities and Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The properties of aviation fuel have a great influence on the performance of oxygenconsuming inerting systems. Based on the establishment of the catalytic inerting process, the flow relationship of each gas component flowing through the catalytic reactor was derived. The mathematical model of the gas concentration in the gas phase of the fuel tank was established based on the mass conservation equation, and the fuel tank model was verified by performing experiments.The results showed that the fuel type exerts a considerably higher influence on the performance of the oxygen-consuming inerting system compared to the corresponding influence on the hollow fiber membrane system, and the relative magnitude of the inerting rates of the four fuel types is RP5 > RP3 > RP6 > JP8. In addition, a higher catalytic efficiency or fuel load rate corresponds to a higher rate of decrease of the oxygen concentration in the gas phase, and the inerting time is inversely proportional to the suction flow rate of the fan. When different fuels are used, the amount of cooling gas and water released from the inerting system are different. Therefore, the influence of fuel type on the system performance should be extensively considered in the future.
基金supported by the Science and Technology Commission of Shanghai Municipality(No.19DZ2270100),China。
文摘Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combinations between polymers and fillers is vital,but blind attempts are often made due to a lack of understanding of the mechanisms involved in the interaction between polymers and fillers.Herein,we employ in-situ polymerization to prepare a polymer based on an ether-nitrile copolymer with high cathode stability as the foundation and discuss the performance enhancement mechanisms of argyrodite and nano-alumina.With 1%content of sulfide interacting with the polymer at the two-phase interface,the local enhancement of lithium-ion migration capability can be achieved,avoiding the reduction in capacity due to the low ion conductivity of the passivation layer during cycling.The capacity retention after 50cycles at 0.5 C increases from 83.5%to 94.4%.Nano-alumina,through anchoring the anions and interface inhibition functions,eventually poses an initial discharge capacity of 136.8 m A h g^(-1)at 0.5 C and extends the cycling time to 1000 h without short-circuiting in lithium metal batteries.Through the combined action of dual fillers on the composite solid-state electrolyte,promising insights are provided for future material design.
基金This research was funded by the Natural Science Research Project of Higher Education Institutions in Anhui Province(Grant No.2022AH040045)the Anhui Provincial Natural Science Foundation(Grant No.2008085QE245)the Project of Science and Technology Plan of Department of Housing and Urban-Rural Development of Anhui Province(Grant No.2021-YF22).
文摘In order to improve the seismic performance of adjacent buildings,two types of tuned inerter damper(TID)damping systems for adjacent buildings are proposed,which are composed of springs,inerter devices and dampers in serial or in parallel.The dynamic equations of TID adjacent building damping systems were derived,and the H2 norm criterion was used to optimize and adjust them,so that the system had the optimum damping performance under white noise random excitation.Taking TID frequency ratio and damping ratio as optimization parameters,the optimum analytical solutions of the displacement frequency response of the undamped structure under white noise excitation were obtained.The results showed that compared with the classic TMD,TID could obtain a better damping effect in the adjacent buildings.Comparing the TIDs composed of serial or parallel,it was found that the parallel TIDs had more significant advantages in controlling the peak displacement frequency response,while the H2 norm of the displacement frequency response of the damping system under the coupling of serial TID was smaller.Taking the adjacent building composed of two ten-story frame structures as an example,the displacement and energy collection time history analysis of the adjacent building coupled with the optimum design parameter TIDs were carried out.It was found that TID had a better damping effect in the full-time range compared with the classic TMD.This paper also studied the potential power of TID in adjacent buildings,which can be converted into available power resources during earthquakes.
基金supported in part by the Shanghai Municipal Science and Technology Major Project (2021SHZDZX0100)Shanghai Municipal Commission of Science and Technology Project (19511132101)National Natural Science Foundation of China (62088101, 61720106011, and 62173034)
文摘1.Introduction Artificial intelligence(AI)is a rapidly growing field of technol-ogy,which“will enliven inert objects,much as electricity did more than a century ago.Everything that we formerly electrified will now cognitize”[1].AI advances are constantly pushing the frontier of what machines can do.Increased attention is being placed on AI research,as well as its development and deployment by commer-cial investors,defense strategists,and policy makers[2].
基金This work was supported by the National Basic Research Program of China(No.2005CB623703)National Natural Science Foundation(No.5047405I)+1 种基金Hunan Provincial Natural Science Foundation of China(No.03JJY3080)Trans-Century Excellent Persons Cultivation Project of Ministry of Education of China(in 2002).
文摘The thermal stresses relaxation of Ni/NiFe2O4 system functionally graded cermet inert anode for aluminum electrolysis was optimally designed. The transient thermal stresses of the inert anode under complex boundary condition during high-temp (955℃) electrolysis were calculated using the finite-element software ANSYS, the influence of different parameters on the distribution of the thermal stresses were analyzed. The results showed that, during the process of thermal shock, the thermal hoop tensile stress on the surface of the anode is very large, which is possibly the major cause of anode crack; when the radius of the anode is between 0.05-0.15m, a range that can be realized by recent manufacturing technology, the optimum composition distribution exponent p is 0.25; The hoop tensile stresses reduce with the decrease of anode scale and also decrease with the decrease of the convection coefficient between the electrolyte and the anode.
基金Scientific Research Fund of Institute of Engineering Mechanics,China Earthquake Administration under Grant Nos.2019EEVL03,2019D14 and 2020EEEVL0401National Natural Science Foundation of China under Grant No.51978525National Key R&D Program of China 2021YFE0112200。
文摘When dealing with the oscillations of fixed-base structures or machines induced by external forces,suppressing the vibrational impact on the adjacent structures and the environment helps to maintain the structural durability and ensure the users′comfort level.This study proposed an inerter-based optimal solution to suppress the vibrational forces and energy transmitted to the supporting ground by utilizing the great potential of the inerter.For the external force,which contains various frequency bands,the stochastic response and an energy balance analysis are conducted to evaluate the force transmissibility,structural displacement,and vibration power flow.Given the benefits of the inerter,a transmitted-force-based optimal design framework is proposed for inerter systems,of which the effectiveness is validated by numerical examples.The obtained results show that inerter systems are capable of providing significant reductions in the structural displacement and the force transmitted to the supporting ground.Particularly,the closed-form power equation indicated that a grounded inerter can suppress the force transmission and vibrational energy,thus leading to a less negative impact on the ground and environment.Revealing the working mechanism and optimal design strategy of the inerter can help solve the force-transmission control problem experienced by some practical structures.
文摘In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamine.This deep blue coordination compound is inert characteristically and remains stable in 1.7 mol/L sulfuric acid,2.4 mol/L hydrochloric or ni- tric acid.It will not be decomposed by masking agents even on boiled,while in that case,almost all the colored coordination com- pounds formed by other metal ions will be decomposed completely.This inert character of the coordination compound of molybdenum(Ⅵ) and its utilization in improving the analytical selectivity have been discussed.In the coexistence of various for- eign ions,especially in the presence of a great quantity of tungsten,which always interferes with the determination of molybdenum,the direct determination of molybdenum in the aqueous solution by applying this system has shown an acceptable sensitivity and reproducibility.From the results of determination in some synthetic and standard samples,it seems feasible to use this system in the determination of molybdenum in nonferrous alloys.
文摘Inert gas-clustered systems (Xn, X = He, Ne, Ar and n = 2 - 20) were established in this study and their stability as a result of interparticulate interaction was examined. Ferric chloride and ferrous oxides were used as catalysts to promote reaction, and 5-nitro-1,2,4-triazol-3-one (NTO) was theoretically synthesized under an inert gas (X6)-clustered environment in this study. The raw material, urea, initially underwent chlorination using chlorine as the reagent, followed by amination, formylation and nitration. Reaction routes closely related to the experimental processes were successfully constructed, and the corresponding energy barriers were estimated for each elementary reaction. The findings revealed that the average errors in the B3LYP/6-31G(d, p)-calculated geometry and vibrational frequency of NTO in an Ne6 system relative to the observed values were 0.83% and 1.84%, respectively. The neon gas-clustered system achieved greater stabilization, which results from the difference in self-consistent field energy (ESCF), than the corresponding stabilization acquired in a helium- or argon-based system. Ferric chloride serves as a good catalyst to reduce the energy barrier of the chlorination reaction, and ferrous oxide is suitable for catalyzing the amination, formylation and nitration reactions, although nitric acid is the better agent for nitration. The catalytic Ne6-clustered reaction system is suggested to be a more feasible pathway for the synthesis of NTO.
基金Project supported by the National Natural Science Foundation of China(Nos.12232014 and 12072221)the Fundamental Research Funds for the Central Universities of China(No.2013017)。
文摘A two-degree-of-freedom(2DOF)vibration isolation structure with an integrated geometric nonlinear inerter(NI)device is proposed.The device is integrated into an inertial nonlinear energy sink(INES),and its vibration suppression performance is examined by the Runge-Kutta(RK)method and verified by the harmonic balance method(HBM).The new isolator is compared with a traditional vibration isolator.The results show a significant improvement in the vibration suppression performance.To investigate the effects of the excitation amplitude and initial condition on the dynamics of the system,a series of transmissibility-frequency response analyses are performed based on the displacement transmissibility.The energy flow of the system is analyzed,and numerous calculations reveal a series of ideal values for the energy sink in the NI-INES system.This study provides new insights for the design of vibration isolators.
基金European Union′s Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie Grant No.INSPIRE-813424(“INSPIRE-Innovative Ground Interface Concepts for Structure Protection”)。
文摘A novel implementation of negative stiffness elements(NSEs)is proposed,utilizing industrial grade nitrogen gas springs as pre-stressed stiffness elements in a configuration with lever arms.This NSE is combined with an inerter to form a stiff dynamic absorber(SDA)for vertical seismic protection of structures with base isolation.The SDA is optimized to minimize vertical accelerations while ensuring static structural integrity,excellent damping performance and containment of relative displacements.The introduction of gas springs in place of conventional linear springs addresses important practical limitations through features of non-linearity and industrial grade manufacturing.The proposed implementation is dimensioned for a 50-ton structure and evaluated numerically for 25 actual earthquake records,in comparison with a linear SDA model and an equivalent conventional damper(CD).Individual and averaged results of acceleration and displacement time histories demonstrate vastly superior response compared to CD regarding induced accelerations for similar displacements.Performance equivalency with the linear SDA model indicates the stability of the gas spring implementation while guaranteeing predictability,tested endurance,proper tolerances,and off-axis motion resistance without requiring additional guiding components,as opposed to conventional springs.These features render the proposed implementation a promising solution for the realization of NSEs in seismic protection.
基金support was received from the National Natural Science Foundation of China(52074156).
文摘To test the effectiveness of N_(2) and CO_(2) in preventing coal from spontaneously combusting,researchers used an adiabatic oxidation apparatus to conduct an experiment with different temperature starting points.Non-adsorbed helium(He)was used as a reference gas,and coal and oxygen concentration temperature variations were analyzed after inerting.The results showed that He had the best cooling effect,N_(2) was second,and CO_(2) was the worst.At 70℃and 110℃,the impact of different gases on reducing oxygen concentration and the cooling effect was the same.However,at the starting temperature of 150℃,CO_(2) was less effective in lowering oxygen concentration at the later stage than He and N_(2).N_(2) and CO_(2) can prolong the flame retardation time of inert gas and reduce oxygen displacement with an initial temperature increase.When the starting temperature is the same,N_(2) injection cools coal samples and replaces oxygen more effectively than CO_(2) injection.The flame retardancy of inert gas is the combined result of the cooling effect of inert gas and the replacement of oxygen.These findings are essential for using inert flame retardant technology in the goaf.
基金supported by the National Research Foundation of Korea(NRF),Government of Korea(MSIT)(2020R1A4A4079810 and 2020R1C1C1009159).
文摘Development of practical lithium(Li)metal batteries(LMBs)remains challenging despite promises of Li metal anodes(LMAs),owing to Li dendrite formation and highly reactive surface nature.Polyolefin separators used in LMBs may undergo severe mechanical and chemical deterioration when contacting with LMAs.To identify the best polyolefin separator for LMBs,this study investigated the separator-deterministic cycling stability of LMBs under practical conditions,and redefined the key influencing factors,including pore structure,mechanical stability,and chemical affinity,using 12 different commercial separators,including polyethylene(PE),polypropylene(PP),and coated separators.At extreme compression triggered by LMA swelling,isotropic stress release by balancing the machine direction and transverse direction tensile strengths was found to be crucial for mitigating cell short-circuiting.Instead of PP separators,a PE separator that possesses a high elastic modulus and a highly connected pore structure can uniformly regulate LMA swelling.The ceramic coating reinforced short-circuiting resistance,while the cycling efficiency degraded rapidly owing to the detrimental interactions between ceramics and LMAs.This study identified the design principle of separators for practical LMBs with respect to mechanical stability and chemical affinity toward LMAs by elucidating the impacts of separator modification on the cycling performance.
基金supported by the National Natural Science Foundation of China(Grant No.51965036).
文摘The cathode spots are a common phenomenon in the TIG(tungsten inert gas)welding process.However,it is rarely observed in the activating TIG welding process.This research is mainly focused on the effect of activating flux on cathode spots in the activating TIG welding.The characteristics and behaviors of cathode spots were investigated in activating TIG welding by the high-speed camera and the spectrograph.Three kinds of oxide(TiO_(2),SiO_(2),MnO_(2))and two halide(MnCl_(2),CaF_(2))activating fluxes are used in the activating TIG welding process.The results show that differ from the TIG welding,the oxide activating flux increases the number of cathode spots and decreases the velocity.The effect is the opposite for the halide activating flux.Moreover,the number of spots no longer varies with the current except TiO2 activating flux.As the temperature of the weld pool surface increases the spot moves away from the center.But this rule is not valid when silica and manganese compounds activating fluxes are used.The variation of cathode spots is caused by the oxide film reformed and the distribution of weld slag.The formation mechanism of cathode spots might be the impact of ions on the cathode surface and the strong electric field formed near the cathode surface.
文摘Welding defects influence the desired properties of welded joints giving fabrication experts a common problem of not being able to produce weld structures with optimal strength and quality. In this study, the fuzzy logic system was employed to predict welding tensile strength. 30 sets of welding experiments were conducted and tensile strength data was collected which were converted from crisp variables into fuzzy sets. The result showed that the fuzzy logic tool is a highly effective tool for predicting tensile strength present in TIG mild steel weld having a coefficient of determination value of 99%.
文摘Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, the process, weld combinations, laser-CMT hybrid welding and applications of CMT welding are critically reviewed. Microstructure and other weld characteristics have been discussed at length for various base metal combinations. Particularly, the welding of aluminium and steel with better results has been possible with CMT Welding. The results reviewed in this article indicate that the CMT-Laser hybrid welding is more preferable to Laser or Laser hybrid welding. CMT welding has found applications in automobile industries, defence sectors and power plants as a method of additive manufacturing.
基金financially supported by the Natural Science Foundation Project of Chongqing City (No.cstc2012jjA50002)
文摘Aging treatment and various heat input conditions and mechanical properties of TIG welded 606I-T6 alloy joints were adopted to investigate the microstructural evolution by microstructural observations, microhardness tests, and tensile tests. With an increase in heat input, the width of the heat-affected zone (HAZ) increases and grains in the fusion zone (FZ) coarsen. Moreover, the hardness of the HAZ decreases, whereas that of the FZ decreases initially and then increases with an increase in heat input. Low heat input results in the low ultimate tensile strength of the welded joints due to the presence of partial penetrations and pores in the welded joints. After a simple artificial aging treatment at 175℃ for 8 h, the microstructure of the welded joints changes slightly. The mechanical properties of the welded joints enhance significantly after the aging process as few precipitates distribute in the welded seam.
文摘Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2—12 Process parameters studied include pH, steady state temperature, concentration, and the type of gases. Greater than 96% hydrolysis was observed in 30 minutes through this process and the rate of destruction increased with the help of more soluble and low thermal inert gas. So with Krypton, omethoate was found to undergo rapid destruction as compared with Argon. In the presence of ultrasound, the observed first order rate of hydrolysis of omethoate is found to be independent of pH. The formation of transient supercritical water(SCW) appears to be an important factor in the acceleration of chemical reactions in the presence of ultrasound. A detailed chemical reaction mechanism for omethoate destruction in water was formulated. Experimental results and theoretical kinetic mechanism demonstrated that the most of the omethoate undergo destruction inside the cavitating holes. A very less effect of temperature on the degradation of omethoate within a temperature range of 20—70℃ proves that a small quantity of omethoate undergoes secondary destruction in the bulk liquid.
基金funding support from the National Natural Science Foundation of China (51722404 and 51674177)
文摘Due to the serious greenhouse gas effects caused by the increasing concentration of atmospheric CO_2,carbon capture and storage(CCS) has been an important area of research and many technologies are developed within this field. Molten salt CO_2 capture and electrochemical transformation(MSCC-ET) process is a desirable method due to a high CO_2 solubility, a wide potential window of molten salts and easily-controlled electrode reactions. Generally, electro-splitting CO_2 in molten salts begins with CO_2 absorption reactions to form CO_3^(2-), which is then followed by the carbon deposition at the cathode and O_2 evolution at the anode. As a result, CO_2 is electro-converted to O_2 and carbon with different morphologies, compositions, microstructures and functional properties. This report introduces the MSCC-ET process, summarizes the reactions occurring in the molten salts and at the electrode surfaces, as well as the morphological variations of the cathodic products. The inert anode materials, cost estimation and scale-up evaluation of the process are then discussed. It is presumed that with a comprehensive understanding of the electrode reactions during electrolysis and the functional properties of carbon materials obtained during CO_2 electro-splitting can provide a foundation for further developing this environmentally friendly process.