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Rare-earth-abundant layered perovskite cathodes of LnBa0.5Sr0.5Co1.5Fe0.5O5+δ (Ln = La and Nd) are exploited for solid oxide fuel cells (SOFCs) at reduced temperatures. Both LaBa0.5Sr0.5Co1.5Fe0.5O5+δ (LBSCF) and NdBa0.5Sr0.5Co1.5Fe0.5O5+δ (NBSCF) show a single tetragonal phase of layered perovskite, which are chemically compatible with the contacted Gd0.2Ce0.8O2-δ (GDC) electrolyte. XPS results indicate a mixed oxidation state of high oxidation state (Fe) and low oxidation state (Co). Both LBSCF and NBSCF exhibit enough high electrical conductivity (＞1000 S/cm) at all operation temperatures. The single cells with LBSCF and NBSCF cathodes achieve good open-circuit voltages (OCVs) of 1.016 V and 1.014 V as well as excellent maximum power densities of 857.07 mW cm−2 and 886.44 mW cm−2 at 800 °C, respectively. The higher output performance of NBSCF cathode is ascribed to its faster surface oxygen exchange as DRT analysis demonstrated. These results indicate that it is promising and practical to exploit rare-earth-abundant layered perovskite cathodes for SOFCs.

Exploring highly active cathode materials with fast cathodic oxygen reduction has been considered as one of the most promising approaches to accelerate the commercialization process of intermediate temperature solid oxide fuel cells (IT -SOFCs). Herein, a highly active hybrid catalyst system with multiphase heterointerfaces consisting of (PrSr)Ni0.5Mn0.5O3-δ, PrOx nanoparticles and (PrSr)2(MnNi)O4-δ is self-assembly formed by substitution of Sr into Pr2Ni0.5Mn0.5O4-δ (S-PNM). Further using S-PNM as cathode materials for IT-SOFCs, S-PNM achieves a remarkable maximum power density of 960 mW cm−2 at 800 °C and an outstanding short-term stability with the discharge voltage of 0.68 V for 80 h. The excellent electrochemical performance by the preliminary experimental results is attributed to the coexistence of multiphase heterointerfaces of (PrSr)Ni0.5Mn0.5O3-δ, (PrSr)2(MnNi)O4-δ and PrOx nanoparticles, which can accelerate cathodic oxygen reduction.

Based on its reduced-temperature redox-stable phenomenon, the state-of-the-art perovskite oxide La0.8Sr0.2MnO3-δ (LSM) is proposed as a novel symmetrical electrode material for solid oxide fuel cells (SOFCs) at intermediate temperatures. LSM exhibits redox instability at high temperatures (≥850 °C) in agreement with the literature, whereas LSM is stable in both fuel and air conditions at intermediate temperatures (≤800 °C). The electrical conductivity of LSM in both air and humidified H2 (3% H2O) exhibit a semiconductor behavior, and the maximum values are 123.8 S cm−1 and 2.01 S cm−1 at 800 °C, respectively. LSM-Gd0.2Ce0.8O2-δ (LSM-GDC) composite electrode was used to improve the electrochemical performance. The area specific resistance of LSM-based electrode decrease from 3.03 Ω cm2 to 1.44 Ω cm2 in air and from 10.49 Ω cm2 to 5.19 Ω cm2 in H2 at 800 °C by adding mixed ionic-electronic conducting GDC, respectively. The electrochemical performance of symmetrical SOFCs with LSM-based electrodes are dramatically enhanced by more than 120 percent at 800 °C. The LSM-GDC composite electrode delivered optimum electrochemical properties with 140 h long-term stability, demonstrating its potential as both anode and cathode for symmetrical SOFCs at intermediate temperatures.

A new concept of high-entropy cathode is reported, which can bring about a definite improvement of electrochemical performance for solid oxide fuel cells (SOFCs). As a proof-of-concept, a new high-entropy perovskite oxide of La0.2Pr0.2Nd0.2Sm0.2Ba0.1Sr0.1Co0.2Fe0.6Ni0.1Cu0.1O3-δ (HEP) is successfully synthesized by a facile one-pot combustion method and proposed as a potential cathode for SOFC at intermediate temperatures. The high-entropy HEP formed a single phase of cubic perovskite structure and matched well with the adjacent electrolyte of Gd0.2Ce0.8O2-δ (GDC). The high-entropy HEP shows a sufficient electrical conductivity of 635.15 S·cm-1 at 800 °C. The high-entropy cathode of HEP achieved a much lower polarization resistance of 0.3 Ω·cm2 on YSZ electrolyte at 800 °C, which was only half of 0.6 Ω·cm2 for conventional La0.8Sr0.2FeO3-δ (LSF) cathode under same conditions. The YSZ-based SOFC with HEP cathode exhibited an outstanding output performance of 714.5 mW·cm-2 at 800 °C, indicating that the high-entropy perovskite as a new-type SOFC cathode is promising.

A new A-site excessive strategy is reported to improve performance of layered perovskite cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). A new A-site excessive Gd1+xBa1+xCo2O5+δ layered perovskite is investigated as cathode materials for IT-SOFCs. With an excess of A-site content, the crystal lattice and the thermal expansion coefficient increase slightly. The oxygen nonstoichiometry (δ) increases, while the oxygen vacancy decreases by defect chemistry analysis. A-site excessive Gd1.05Ba1.05Co2O5+δ (GBC1.05) is well compatible with Gd0.2Ce0.8O2-δ at 1000 °C for 10 h. The electrical conductivity of GBC1.05 increases dramatically owing to the higher concentration of electron hole and the lower oxygen vacancy concentration. The electrochemical performance towards oxygen reduction reaction can be enhanced from 0.246 Ω cm2 to 0.146 Ω cm2 by introducing A-site excessive content of Gd and Ba. Consequently, GBC1.05 cathode exhibits a good cell performance of 830 mW cm−2 at 800 °C, indicating that A-site excessive Gd1.05Ba1.05Co2O5+δ layered perovskite is a potential cathode material for IT-SOFCs due to its high electrochemical performance.

Mo-doped Pr0.6Sr0.4Fe0.8Ni0.2O3-δ (PSFNM) perovskites are synthesized by a modified Pechini method and evaluated as both anode and cathode for intermediate-temperature symmetrical solid oxide fuel cell (SSOFC). The influence of Mo-doping on structure, conductivity, thermal expansion coefficient and electrochemical performance of Pr0.6Sr0.4Fe0.8Ni0.2O3-δ (PSFN) electrode are investigated. The results indicate that PSFNM exhibits a cubic perovskite structure and shows a good reversibility. After heated at 800 °C for 10 h in humidified H2, some new phases of SrPrFeO4, Pr2O3, and Fe-Ni alloy in PSFNM are identified by powder X-ray diffraction analysis. Although the conductivity of Mo-doped sample is slightly decreased, the thermal expansion compatibility and hydrogen oxidation reaction (HOR) activity are gradually improved. The maximum power density of SSOFC increase from 435 mW/cm2 to 500 mW/cm2 at 800 °C, and the corresponding polarization resistance decrease from 0.102 Ω.cm2 to 0.070 Ω.cm2, respectively. In addition, the SSOFC with PSFNM electrode shows a robust stability after operating at 700 °C for 100 h. These results demonstrate that PSFNM is a promising electrode for SSOFC at intermediate temperatures.

Keeping the advantages of symmetrical solid oxide fuel cells (SSOFCs) with redox-stable electrodes, novel SSOFCs with redox-reversible cermet electrodes are proposed to solve the major problems of low electronic conductivity ( 10 S.cm−1) under anode atmosphere and poor electrochemical activity for fuel oxidation. The conventional Ni0.7Co0.3O-Ce0.8Sm0.2O1.9 (NC-SDC) cermet anode is applied simultaneously as a potential redox-reversible cathode for SSOFCs with practical yttria-stabilized zirconia (YSZ) electrolytes. The electrochemical performance of SSOFCs with NC-SDC cermet electrode can be improved via SDC buffer layers and the corresponding maximum power density increases from 140.1 mW cm−2 to 200.2 mW cm−2 at 800 °C. The new redox-reversible cermet electrodes of SSOFCs open doors for development of next-generation SSOFC electrode materials.

Study engagement is a positively learning status among adolescents. The aim of this study was to test if self-concept clarity and intentional self-regulation mediate between social anxiety and study engagement. Participants were 1597 Chinese adolescents (48.2%male, aged 13-23 years, M=17.45 years, SD=3.04 ;) they completed measures of social anxiety self-concept clarity, intentional self-regulation and study engagement. The study used structural equation modeling to test for a mediating effect; self-concept clarity and intentional self-regulation were found to fully mediate between social anxiety and study engagement. ISR and SCC indirectly affected SE had no significant. These findings suggest that self-concept clarity and intentional self-regulation underlie social effect on adolescents' study engagement.

Antimony was doped to barium strontium ferrite to produce ferrite-based perovskites with a composition of Ba0.5Sr0.5Fe1−xSbxO3−δ (x = 0.0, 0.05, 0.1) as novel cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The perovskite properties including oxygen nonstoichiometry (δ), mean valence of B-site, tolerance factors, thermal expansion coefficient (TEC) and electrical conductivity (σ) are explored as a function of antimony content. By defect chemistry analysis, the TECs decrease since the variable oxygen vacancy concentration is decreased by Sb doping, and σ decreases with x due to the reduced charge concentration of Fe4+ content. Consequently, the electrochemical performance was substantially improved and the interfacial polarization resistance was reduced from 0.213 to 0.120 Ωcm2 at 700 °C with Sb doping. The perovskite with x = 1.0 is suggested as the most promising composition as SOFC cathode material.

Symmetrical solid oxide fuel cell (SSOFC) using same materials as both anode and cathode simultaneously has gained extensively attentions, which can simplify fabrication process, minimize inter-diffusion between components, enhance sulfur and coking tolerance by operating the anode as the cathode in turn. With keeping the SSOFC's advantages, a novel quasi-symmetrical solid oxide fuel cell (Q-SSOFC) is proposed to further improve the performance, which optimally combines two different SSOFC electrode materials as both anode and cathode simultaneously. PrBaFe2O5+δ (PBFO) and PrBaFe1.6Ni0.4O5+δ (PBFNO, Fe is partially substituted by Ni.) are prepared and applied as both cathode and anode for SSOFC, which exhibit desirable chemical and thermal compatibility with Sm0.8Ce0.2O1.9 (SDC) electrolyte. PBFO cathode exhibits higher oxygen reduction reaction (ORR) activity than PBFNO cathode in air, whereas PBFNO anode exhibits higher hydrogen oxidation reaction (HOR) activity than PBFO anode in H2. The as-designed Q-SSOFC of PBFNO/SDC/PBFO exhibits higher electrochemical performance than the conventional SSOFCs of both PBFO/SDC/PBFO and PBFNO/SDC/PBFNO. The superior performance of Q-SSOFC is attributed to the lowest polarization resistance (Rp). The newly developed Q-SSOFCs open doors for further improvement of electrochemical performance in SSOFC, which hold more promise for various potential applications.

Ba0.5Sr0.5Co0.2Fe0.8O3-δ (BSCF) is one of the best electrode materials for fuel cells and batteries. However, the stability of BSCF electrode is a challenge for the application of symmetrical solid oxide fuel cells (SSOFCs), and its electrochemical performance is still far from desirable. Herein, we propose that Mo doping in BSCF electrode can not only improve the electrode stability and but also effectively enhance electrochemical performance in YSZ-based SSOFCs. Ba0.5Sr0.5Co0.2Fe0.7Mo0.1O3-δ (BSCFM) electrode materials and Gd0.2Ce0.8O2-δ (GDC) buffer layer materials were synthesized by a gel combustion method. The SSOFC with a configuration of BSCFM│GDC│YSZ│GDC│BSCFM was constructed by using BSCFM as the cathode and anode, GDC as the buffer layer and YSZ as the electrolyte. The results show that the as-synthesized BSCFM electrode exhibits a cubic perovskite structure, and a remarkable stability under reducing environment. By the substitution of Mo, the interface polarization resistances were decreased from 0.051 Ω cm2 to 0.035 Ω cm2 in H2 at 800 °C. Using humid H2 (3% H2O) as fuel and static air as oxidant, the output power of the single cell is as high as 418 mW/cm2, which can work stably at 700 °C for 115 h. This work demonstrates a stable SSOFC with YSZ electrolyte and BSCF-based electrode.

Propagation properties of two laser pulses in multilevel photoionization atomic vapor systems are researched theoretically under the circumstances of Doppler broadening and two isotopes. It is shown that group velocity dispersion and ‘concomitant oscillation’ of laser pulses exist during laser propagation. The influences of Doppler broadening and isotope shift on laser propagation properties, atomic ionization yields and selectivity are studied. Besides, variation in r-direction is taken into consideration to approach physical practice. The simulation results provide references for experimental design in laser isotope separation (LIS).

Y 0.8 Ca 0.2 BaCo 4 O 7+ δ (YCBC4) was synthesized and investigated as a cathode for proton-conducting intermediate temperature solid oxide fuel cells (IT-SOFCs). Low thermal expansion coefficient (TEC) (~9.9×10 −6 K −1 ) can provide good thermal expansion compatibility with the standard SOFC electrolyte materials. Laboratory-sized quad-layer cells, consisting of NiO–BaZr 0.1 Ce 0.7 Y 0.2 O 3− δ (BZCY)/NiO–BZCY/BZCY/YCBC4, were fabricated by a one-step dry-pressing/co-firing process and tested from 550 to 700 °C with humidified hydrogen (~3% H 2 O) as the fuel and static air as the oxidant, respectively. An excellent power density of 472 mW cm −2 and a low electrode polarization resistance of 0.121 Ω cm 2 were obtained at 700 °C. Preliminary results demonstrated that the YCBC4 can be a promising cathode material for proton-conducting IT-SOFCs.

A layered perovskite oxide Y0.8Ca0.2BaCoFeO5+d (YCBCF) was synthesized as a novel cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs) by citric acid-nitrates self-propagating combustion method. The phase and microstructure of YCBCF were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The average thermal expansion coefficient (TEC) of YCBCF was 14.6×10−6 K−1, which was close to other materials of SOFC at the range of RT-1000 °C. An open-circuit potential of 0.75 V and a maximum output power density of 426 mW/cm2 were obtained at 650 °C in a Sm0.2Ce0.8O1.9 (SDC)-based anode-supported SOFC by using humidified (∼3% H2O) hydrogen as fuel and static air as oxidant. The results indicated that the YCBCF was a promising cathode candidate for IT-SOFCs.

Mixed rare-earth (La, Pr)0.8Sr0.2FeO3−δ–Sm0.2Ce0.8O2−δ (LPSF–SDC) composite cathode was investigated for proton-conducting solid oxide fuel cells based on protonic BaZr0.1Ce0.7Y0.2O3−δ (BZCY) electrolyte. The powders of La0.8−xPrxSr0.2FeO3−δ (x = 0, 0.2, 0.4, 0.6), Sm0.2Ce0.8O2−δ (SDC) and BaZr0.1Ce0.7Y0.2O3−δ (BZCY) were synthesized by a citric acid-nitrates self-propagating combustion method. The XRD results indicate that La0.8−xPrxSr0.2FeO3−δ samples calcined at 950 °C exhibit perovskite structure and there are no interactions between LPSF0.2 and SDC at 1100 °C. The average thermal expansion coefficient (TEC) of LPSF0.2–SDC, BZCY and NiO-BZCY is 12.50 × 10−6 K−1, 13.51 × 10−6 K−1 and 13.47 × 10−6 K−1, respectively, which can provide good thermal compatibility between electrodes and electrolyte. An anode-supported single cell of NiO-BZCY|BZCY|LPSF0.2–SDC was successfully fabricated and operated from 700 °C to 550 °C with humidified hydrogen (∼3% H2O) as fuel and the static air as oxidant. A high maximum power density of 488 mW cm−2, an open-circuit potential of 0.95 V, and a low electrode polarization resistance of 0.071 Ω cm2 were achieved at 700 °C. Preliminary results demonstrate that LPSF0.2–SDC composite is a promising cathode material for proton-conducting solid oxide fuel cells.

The purpose is to develop alternative alkaline-earth-free quasi-ternary LaCoO3−LaNiO3−LaFeO3 cathode materials for solid oxide fuel cells (SOFCs), which demonstrate high electrical conductivity, good electrochemical performance and excellent chemical stability against CrO2(OH)2 released from the metallic interconnects at operation temperatures. Three different perovskites of lanthanum in combination with iron, cobalt and nickel oxides, i.e. LaFe0.8Co0.1Ni0.1O3−δ (LFCN), LaNi0.8Co0.1Fe0.1O3−δ (LNCF) and LaCo0.8Fe0.1Ni0.1O3−δ (LCFN), were synthesized by the modified Pechini method, and then systematically investigated in the phase structure, thermal expansion, electrical conductivity and catalytic activity. LFCN have the best combination to the requirements of high-performance cathodes for SOFCs. Button cells with LFCN cathode were prepared on anode-supported YSZ electrolyte with gadolinium-doped cerium (GDC) buffer layer by screen printing. Excellent electrochemical performance with high maximum power density of 643 mW.cm−2 at 750 °C and corresponding low polarization resistance of 0.62 Ω cm2 further demonstrate that LFCN is a very competitive candidate as SOFC cathode.

The flow properties and substrate deposition rate profile, which are the important parameters in electron beam physical vapor deposition, are investigated computationally in this article. Collimators are used to achieve the desired vapor beam and deposition rate profile in some applications. This increases the difficulty measuring boundary conditions and the size of the liquid metal pool inside the collimators. It is accordingly hard to obtain accurate results from numerical calculations. In this article, two-dimensional direct simulation Monte Carlo (DSMC) codes are executed to quantify the influence of uncertainties of boundary conditions and pool sizes. Then, three-dimensional DSMC simulations are established to simulate cerium and neodymium evaporation with the collimator. Experimental and computational results of substrate deposition rate profile are in excellent agreement at various evaporation rates and substrate heights. The results show that the DSMC method can assist in metal evaporation with a collimator.

Nowadays, augmented reality (AR) has entered our lives. An AR tag is usually used and stacked on the products for sake of being detected and recognized easily. With the recognized pattern, AR system thereby can superimpose the corresponding virtual object on the AR tag. The AR tag, however, distort the perception of products. In this study, we proposed a method that the AR tag could be embedded on a digital screen by applying the technique of temporal psycho visual modulation (TPVM). The new method utilizes the differences between the human-eye perception and digital camera image-forming to stack an invisible AR tag on digital screen and projector. The AR tag can be detected by digital devices but not yet by human eyes. Based on this concept of AR and TPVM, the related applications would be achieved, such as the immersive virtual scene created in entertainment, commercial and entertainment.

Interaction Training Logic Model. Abstract. On the purpose of radar operators ability improving, for a man-in-the-loo p training system a radar interaction training logic (RITL) model is proposed obeying the entity-action-task-interaction (EATI) military concept modeling rules. The radar interactive training space in RITL model consists of entities, activities, rules and interface four components through which the operational ability of radar trainees in electronic counter-countermeasure (ECCM) environment could be characterized . In virtue of the joint use of typical models in radar ECCM system simulation such as radar radiative electromagnetic environment (EME) model, jamming models, radar ECCM models and RITL model, a complete interaction architecture for surveillance radar operators training is illustrated in this paper as well. The preliminary results of experiment show that the operational ability of different trainees could be distinguished which indicates the archetypal system being efficient and acceptable.

A cobalt-free Ba0.5Sr0.5Fe0.9Ni0.1O3−δ–Sm0.2Ce0.8O1.9 (BSFN–SDC) composite was employed as a cathode for proton-conducting solid oxide fuel cells (H-SOFCs) using BaZr0.1Ce0.7Y0.2O3−δ (BZCY) as the electrolyte. The chemical compatibility between BSFN and SDC was evaluated. The XRD results showed that BSFN was chemically compatible with SDC after co-fired at 1100 °C for 5 h. The thermal expansion coefficient (TEC) of BSFN–SDC, which showed a reasonably reduced value (16.08 × 10−6 K−1), was effectively decreased due to Ce0.8Sm0.2O1.9 (SDC) added. A single cell of Ni–BZCY/Ni–BZCY/BZCY/BSFN–SDC with a 25-μm-thick BZCY electrolyte membrane exhibited excellent power densities as high as 361.8 mW cm−2 at 700 °C with a low polarization resistance of 0.174 Ω cm2. The excellent performance implied that the cobalt-free BSFN–SDC composite was a promising alternative cathode for H-SOFCs.

A stable, easily sintered perovskite oxide BaCe 0.5 Zr 0.3 Y 0.16 Zn 0.04 O 3− δ (BCZYZ) as electrolyte for proton-conducting solid oxide fuel cells with Ba 0.5 Sr 0.5 Zn 0.2 Fe 0.8 O 3− δ –BaCe 0.5 Zr 0.3 Y 0.16 Zn 0.04 O 3− δ (BSZF–BCZYZ) composite cathode was investigated. Thin proton-conducting BCZYZ electrolyte was prepared over porous anode substrate composed of NiO–BCZYZ by the one-step dry-pressing/co-firing method. A laboratory-sized tri-layer cell of NiO–BCZYZ//BCZYZ (∼21 μm)/BSZF–BCZYZ (∼32 μm) was operated from 550 to 700 °C with humidified hydrogen (∼3% H 2 O) as fuel and the static air as oxidant. The BCZYZ perovskite electrolyte synthesized by a modified Pechini process was completely dense after sintered at 1250 °C for 5 h, lower than that without Znic dopant about 150 °C. An open-circuit potential of 1.007 V, a maximum power density of 387 mW cm −2 , and a low polarization resistance of the electrodes of 0.11 Ω cm 2 were achieved at 700 °C.

A stable, easily sintered perovskite oxide BaCe0.5Zr0.3Y0.16Zn0.04O3−δ (BCZYZ) as electrolyte for proton-conducting solid oxide fuel cells with layered SmBa0.5Sr0.5Co2O5+δ (SBSC) cathode is investigated. Thin proton-conducting BCZYZ electrolyte is prepared over porous anode substrate composed of NiO-BCZYZ by the one-step dry-pressing/co-firing method. A laboratory-sized tri-layer cell of NiO-BCZYZ/BCZYZ (∼17 μm)/SBSC is operated from 550 to 700 °C with humidified hydrogen (∼3% H2O) as fuel and the static air as oxidant. The BCZYZ perovskite electrolyte synthesized by a modified Pechini process is completely dense after sintered at 1250 °C for 5 h, lower than that without Znic dopant about 150 °C. An open-circuit potential of 1.007 V, a maximum power density of 0.306 W cm−2, and a low polarization resistance of the electrodes of 0.11 Ω cm2 are achieved at 700 °C.

Ratcheting Devices are often used in automatic transmissions to provide a unidirectional power flow to achieve specific gear functions. These devices consist of two members that rotate relative to each other and a locking mechanism between these two rotating parts. In order to meet certain gearshift needs, the ratcheting device performs a combined overrun and engagement function. In both modes the components experience high-speed rotation and are subjected to significant impact forces. The high impact forces between the components may cause damage on the parts and the device may fail to function as intended. It is important to understand the dynamic behaviors of these ratcheting devices and the key design factors affecting their performances under various operating conditions. Vehicle tests and/or laboratory tests are often conducted to investigate the dynamic performance of these devices. However, these tests are costly and time consuming and sometimes impossible to simulate the real world situations. It makes dynamic modeling essential to help better understand the dynamic characteristics of the ratcheting device, and to provide design engineers with physical insights and direction for problem resolution. In this paper we describe the development of a dynamic model with ADAMS to simulate a ratcheting device in automatic transmission systems. The dynamic behaviors of the ratcheting device are investigated under various operating conditions. The mechanism consists of two rotating parts, namely, the notch plate and pocket plate. A locking component called strut sits in the pocket plate with a preloaded spring located in the pocket underneath to provide the necessary engaging force. In the dynamic modeling, all the rotating inertias of the connecting parts are lumped into the notch plate and the pocket plate. The strut is modeled as a solid body with 6-degree of freedom, governed entirely by contact, impact, fluid damping, and spring forces. Real world operating situations are taken as the input loading conditions. The key design parameters that affect the dynamic behaviors of the mechanism are investigated in this study.