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In this brief, we present a miniaturized spoof surface plasmon polaritons (SPPs) load for planar terahertz (THz) circuit application on thick substrate. The proposed SPP cell consists of a groove-shaped structure integrated with a folded stub. The coupling between the stub and the grooves enlarges the capacitance, reduces the cutoff frequency, and miniaturizes the SPP size. The strong field confinement of the SPP waveguide leads to tremendous insertion loss near the cutoff frequency. Furthermore, due to the low conductivity and high permeability, the SPP structures made of nickel (Ni) metal increase the metallic loss to 40 folds that of the aluminum (Al) case, effectively absorbing the propagating electromagnetic wave. Therefore, the tapered SPP structure made of Ni metal can operate as a load with a compact size of 1.7 λg × 0.23 λg (λg is the guided wavelength at 300 GHz). The reflection coefficient of this compact SPP load is below -20 dB in the 195 -500 GHz band. Finally, this SPP load is utilized in an equal-power two-way Goubau-line divider, with 0.194 λg substrate thickness, operating in 220-325 GHz band. The simulated and experimented results are consistent, indicating that the proposed compact SPP load could serve as a matching load for THz multiple-port circuit application on thick substrate.

Filtration by the fibrous medias is recognized as one of the most effective methods to control particulate pollution. A type of 3-D mesh spacer filter (3-D filter) proposed is effective for filtrating the large particles with low pressure drop. This study described the flow characteristics of dust-containing gas within the 3-D filter by means of CFD-DEM model. The influences of air velocity, particle concentration and restitution coefficient of particle on the filtration performance as well as the particles deposition process were simulated. The results showed that the particles capturing efficiency of 3-D filter was increased with the air velocity and particle concentration while the particles rebound made the filtration efficiency decreased when the air speed was increased more than 3.0 m/s. For the particle properties, the smaller restitution coefficient, the higher filtration efficiency. When the quality of particle deposition was increased to 70 g/m2, the filtration efficiency almost remained unchanged.

Cu0.27Co2.73O4 nanooctahedrons enclosed by polar {111} planes have been prepared through the selective adsorption of Cl-. Hydrogenation has been successfully used to enhance the responses of the Cu0.27Co2.73O4 nanooctahedron sensors to acetone, ethanol, and n-butylamine. The enhancement of the response results from the increase in the number of 3-coordinated Co/Cu atoms (Co3c/Cu3c) at the (111) plane of Cu0.27Co2.73O4 through removing O-H groups and Cl- ions at the surface by hydrogenation. The Co3c/Cu3c atoms on the (111) plane of Cu0.27Co2.73O4 are considered to function as the gas response active centers. These Co3c/Cu3c active atoms have three functions: generating electrons, adsorbing oxygen from air, and catalyzing the sensing reactions. The hydrogenation polar surface approach can be applied to improve the performances of other sensing materials. Such sensing mechanisms of the Co3c/Cu3c unsaturated atoms as the active centers can be conducive to understanding the gas-sensing essence and the development of sensing materials with high performances.

We propose a compact integral imaging 2D/3D compatible display based on a liquid crystal (LC) micro-lens array. The LC micro-lens array is combined with a polarisation switching layer (PSL) to real...

Magnetic resonance imaging (MRI)-guided high-intensity focused ultrasound (HIFU) has been applied as a therapeutic tool in the clinic, and enhanced MRI contrast for depiction of target tissues will improve the precision and applicability of HIFU therapy. This work presents a "spotlight MRI" contrast enhancement technique, which combines four essential components: periodic HIFU stimulation, strong modulation of T1 caused by HIFU, rapid MRI signal collection, and spotlight MRI spectral signal processing. The T1 modulation is enabled by a HIFU-responsive nanomaterial based on mesoporous silica nanoparticles with Pluronic polymers (Poloxamers) and MRI contrast agents attached. With periodic HIFU stimulation in a precisely defined region containing the nanomaterial, strong periodic MRI T1-weighted signal changes are generated. Rapid MRI signal collection of the periodic signal changes is realized by a rapid dynamic 3D MRI technique, and spotlight MRI spectral signal processing creates modulation enhancement maps (MEM) that suppress background signal and spotlight the spatial location with nanomaterials experiencing HIFU stimulation. In particular, a framework is presented to analyze the trade-offs between different parameter choices for the signal processing method. The optimal parameter choices under a specific experimental setting achieved MRI contrast enhancement of more than 2 orders of magnitude at the HIFU focal point, compared to controls.

Ni(OH)2-based materials are widely studied in oxygen evolution reaction (OER), but no related synthesis, electrocatalytic application, or theoretical analysis of Sn4+-doped Ni(OH)2 has been reported. In this work, Sn-Ni(OH)2 with a homogeneously distributed nanosheet array was synthesized through a one-step hydrothermal process. It displays a hugely enhanced catalytic activity compared to undoped Ni(OH)2 throughout the OER and hydrogen evolution reaction (HER) processes. The overpotentials at 100 mA cm-2 of Sn-Ni(OH)2 are 312 mV (OER) and 298 mV (HER), which are lower than the corresponding 396 and 427 mV of Ni(OH)2, respectively. In addition, Sn-Ni(OH)2 can deliver stable large current densities (at ≈500 and ≈1000 mA cm-2) for the long-term (>100 h) chronoamperometry testing. Moreover, Sn-Ni(OH)2 illustrates catalytic activity comparable to that of a commercial Pt/C||RuO2 electrode pair during the overall water splitting course. Both experimental phenomena and relevant computed theoretical data confirm that the enhanced water splitting activity is mainly due to the introduced Sn4+ site, which acts as the active center activates the nearby Ni sites during the OER, while acting as the most active reaction site that participates in the HER. Although the doped Sn4+ has two different effects on OER and HER proceedings, water splitting performance of Sn-Ni(OH)2 has been conspicuously improved.

High-quality ferroelectric films of Mn-doped Pb(Zr0.3Ti0.7)O3 (PMZT) were prepared using the sol-gel method, and the temperature dependence of ferroelectric, dielectric, and leakage current properties (J–E) were explored in detail using the top electrode/ferroelectric films/bottom electrode capacitor heterostructure. The enhancement of polarization and dielectric properties by element doping is clearly observed by 3% Mn-doping. Such enhancement is beneficial for the application of these films in ferroelectric random-access memory. In addition, the analysis of leakage current reveals symmetric behavior with 3% Mn-doping and the leakage current density gradually increases with increasing temperature, which may be due to the movement of domain wall and oxygen vacancy. The dominant leakage current conduction mechanism is bulk-limited ohmic or interface-limited Schottky emission conduction within a wide temperature range. The results might be meaningful for further work on ferroelectric electrical devices with improved ferroelectric and dielectric properties.

In this work, the microstructure evolution, thermal expansion, thermal conductivity, and thermal shock resistance properties of the plasma-sprayed X1-Gd2SiO5, X2-Y2SiO5, and X2-Er2SiO5 coatings were evaluated and compared by experimental measurement and theoretical exploration. Results showed that significant microstructure evolution such as crystallization of amorphous phase, grain growth, and defects reduction was observed in the RE2SiO5 coatings after thermal aging at 1400 °C. The X1-Gd2SiO5 coating exhibited higher CTE values than the X2-Y2SiO5 and X2-Er2SiO5 coatings, which was related to their crystal structure. The thermal conductivity of thermal-aged RE2SiO5 coating was much higher than that of the as-sprayed RE2SiO5 coating, and thermal conductivity was determined not only by crystal structure but also mainly by the microstructure of the coatings. The X2-Y2SiO5 and X2-Er2SiO5 coatings with lower thermal mismatch stresses presented much better thermal shock resistance than the X1-Gd2SiO5 coating.

银作为一种功能性材料, 由于其优良的导电性而用作于汽车电子的电接触材料。但是, 这种材料极易遭受大气腐蚀问题, 并导致结构的损坏和器件的失效。本文研究了应用于印刷电路板中导电银的腐蚀行为, 并从动力学和机理方面发现了影响材料结构损害最主要的环境因素(SO2污染物、温度和相对湿度(RH, Relative humidity))。相较于其他因素, 温度(55 °C)是运行环境中引起导电材料结构变化的最主要因素, 并且表面的腐蚀层厚度达到了最大值, 即dfilm=15.56× 10-5 μm。然而, 在腐蚀过程中, SO2污染物和RH促进了腐蚀物质的扩散, 并也会增加腐蚀产物层(Ag2S和Ag2SO4)的厚度。因此, 本文不仅大大增强了人们对于不同环境因素下导电材料结构损害的认识, 同时也为实际生产中的防腐设计和材料选择提供了重要的指导。

In this brief, we propose a spoof surface plasmon polariton (SPP) filter with reconfigurable dual and non-linear notched frequencies. The SPP waveguide with asymmetrical geometry leads to asymmetrical field confinement depending on the groove orientation. By loading half-wavelength SPP resonators along the weaker field confinement side of the asymmetrical SPP waveguide, dual notches can be generated in the SPP transmission. Meanwhile, since the dispersion of SPP cell is not linear, the dual notched frequency locations are also non-linearly spaced. Varactor diodes, with voltage controllable capacitance, are incorporated into the SPP resonators to engineer the SPP non-linear dispersion. Thus, the SPP effective wavelength can be altered and the dual-notched frequencies be tuned. Two reconfigurable notched frequencies are achieved at 4.29/5.69, 4.045/5.27 and 3.765/4.85 GHz with 16, 4.5 and 0 V bias, respectively.

A real-time and visible stress monitoring method based on a pure organic mechanoresponsive luminogen (MRL) was proposed in this work. 1,1,2,2-tetrakis(4-nitrophenyl)ethene (TPE-4N) could produce ultrasensitive and visible mechanoresponsive fluorescence. Metal specimens were coated with a uniform TPE-4N film, wherein mechanical deformation was transformed into visible fluorescence. Tensile tests were conducted to determine the calibration relationship between the stress value and fluorescence intensity. The accuracy of stress measured using the organic MRL method was investigated on single-edge notched tension specimens. Results show that the stress distribution obtained using the proposed method agrees well with that calculated using ANSYS simulation. The organic MRL method may open up new opportunities for large-scale, full-field, on-site monitoring of stress distribution in complicated structural components.

Environmental barrier coatings (EBCs) have been widely studied for the protection of ceramic matrix composites (CMCs). The phase transition of silica thermal growth oxide (TGO) has been proved to be an important factor for the durability of EBCs. Yb2O3 could react with SiO2 TGO and form silicate which may improve the stability of TGO and prolong the service life of EBCs. In the present work, Si coatings doped with different contents of Yb2O3 were fabricated by vacuum plasma spray. The oxidation behaviors of the composite coatings were evaluated at 1350 °C and compared with the pure Si coating. The evolution of phase composition and microstructure of mixed thermal growth oxide (mTGO) was characterized in detail. The results showed that the newly formed oxidation product, namely Yb2Si2O7, could reduce the vertical cracks in mTGO layer and the mTGO/coating interface cracks, leading to a better binding performance of the mTGO layer. The oxidation mechanisms of the Yb2O3-doped Si coatings were analyzed based on microstructure and phase composition observations.

Transparent laser ceramics are the attractive gain medium for solid-state lasers. However, they have not been applied to the fiber lasers due to the difficulty of forming green fibers by traditional methods. In this study, a novel route combined aqueous gelcasting with capillary glass tube was designed to prepare Yb:YAG transparent ceramic fiber with a diameter of 1.0 mm and 43.0 mm in length for the first time. The slurry with high solid loading and low viscosity was smartly inhaled into the capillary glass tube to conquer the difficulty of casting. The green fibers without cracks and deformation had highly dense microstructure. The in-line transmittance of highly doped 15.0 at.% Yb:YAG transparent ceramic disc prepared from the same preparation conditions of Yb:YAG ceramic fiber was 80.0 % at 1064 nm. This study provides a novel route to prepare transparent ceramic fiber differing from extrusion processing, promoting the development of fiber laser.

In this brief, an ultra-wideband and compact planar terahertz matching load based on spoof surface plasmon polaritons (SPPs) is proposed. As a result of subwavelength field confinement and huge metallic loss near the cutoff frequency of SPP waveguides, a tapering SPP structure with nickel (Ni) can terminate the circuit with quasi- $50~{\Omega }$ impedance. The Ni-SPP structure can absorb most of the propagating electromagnetic wave as a matching load. The voltage standing wave ratio (VSWR) of this proposed Ni-SPP load, with half a wavelength in length at 250 GHz, is below 1.2 from 150 GHz to 1000 GHz. In order to demonstrate its feasibility in terahertz circuits, this SPP load is then applied in a conventional two-way power divider working from 220 to 325 GHz. The simulated and experimental results show that it has performance similar to that of an ideal load, indicating that the proposed SPP load could have lots of potential applications in terahertz planar multiple-port circuits.

Phase equilibria and phase diagram of the (Li+, K+//Cl–, $${\text{SO}}_{4}^{{2 - }}$$ ‒H2O) quaternary water–salt system is very important for the separation of potassium and lithium from the salt lake brines in Qaidam Basin. The compositions, densities, and refractive indices of saturated solutions in the (Li+, K+//Cl–, $${\text{SO}}_{4}^{{2 - }}$$ ‒H2O) quaternary system at 288.15 K have been measured experimentally with isothermal dissolution equilibrium method, and the solid phases have been identified by the X-ray powder analysis. In the phase diagrams of this quaternary system at 288.15 K, there are five minerals corresponding to KCl, LiCl·H2O, K2SO4, Li2SO4·H2O, and the double salt Li2SO4·K2SO4 existed in this system. K2SO4 occupies the greatest part of phase region, while LiCl· H2O covers the smallest. These results show that K2SO4 could be easily crystallized and separated from this system.

Ce:Y3Al5O12 transparent ceramics (TCs) with appropriate emission light proportion and high thermal stability are significant to construct white light emitting diode devices with excellent chromaticity parameters. In this work, strategies of controlling crystal-field splitting around Ce3+ ion and doping orange-red emitting ion, were adopted to fabricate Ce:(Y,Tb)3(Al,Mn)5O12 TCs via vacuum sintering technique. Notably, 85.4 % of the room-temperature luminescence intensity of the TC was retained at 150 °C, and the color rendering index was as high as 79.8. Furthermore, a 12 nm red shift and a 16.2 % increase of full width at half maximum were achieved owing to the synergistic effects of Tb3+ and Mn2+ ions. By combining TCs with a 460 nm blue chip, a warm white light with a low correlated color temperature of 4155 K was acquired. Meanwhile, the action mechanism of Tb3+ ion and the energy transfer between Ce3+ and Mn2+ ions were verified in prepared TCs.

Transparent ceramics (TCs) with high color rendering index (CRI) are considered as excellent color converters for white light-emitting diode (LED) and laser diode (LD) devices. In this study, by utilizing the component and structural designs between layers, composite structure (Ce,Cr):YAG/Ce:YAG and Cr:YAG/Ce:YAG TCs with high CRI were fabricated by vacuum sintering. Microstructural and luminescence properties, as well as energy transfer from Ce3+ to Cr3+ ions of as-fabricated TCs were explored systematically. Simultaneously, TC based white LEDs/LDs were assembled via the remote excitation mode. Under 460 nm excitation, a high CRI value of 75.2 was realized in (Ce,Cr):YAG/Ce:YAG TC based white LEDs. As increasing the thickness of the Cr:YAG layer in Cr:YAG/Ce:YAG TC, its red emission intensity could be enhanced distinctly. The optimized CRI and CCT values could reach 74.4 and 4146 K, respectively. In addition, the optimized luminous flux (LF) and CRI of Cr:YAG/Ce:YAG TC based LD device were 160.6 lm and 69.1, respectively. Therefore, the composite structure design is an effective approach to realize the essential promotion of CRI value in TC based white LED/LD devices.

Metallic zinc is attractive anode material of rechargeable aqueous Zn-based batteries due to its ambient stability, high volumetric capacity, and abundant reserves. Nonetheless, Zn anodes suffer from issues such as low coulombic efficiency (CE), large polarization and dendrite formation. Herein, uniform Zn electrodeposition is reported on carbon substrates by selective nitrogen doping. Combined experimental and theoretical investigations demonstrate that pyrrolic and pyridinic nitrogen doped in carbon play beneficial effect as zinc-philic sites to direct nucleation and growth of metallic Zn, while negligible effect is observed for graphite nitrogen in Zn plating. The carbon cloth with modified amount of doped pyrrolic and pyridinic nitrogen stabilizes Zn plating/stripping with 99.3% CE after 300 cycles and significantly increases the deliverable capacity at high depth of charge and discharge compared to undoped carbon substrate and Zn foil. This work provides a better understanding of heteroatom doping effect in design and preparation of stable 3D carbon-supported zinc anode.

To study the influence of consolidation stress ratio and stress history on 1-D consolidation permeability of saturated clay, one-dimensional consolidation permeability tests were carried out with GDS triaxial device. The results indicated that the permeability coefficient and void ratio of normally and overconsolidated saturated clay decreased with the increase of consolidation stress ratio under different consolidation stress ratios but the same stress history. And the amount of final sample’s compression increased with the increase of the consolidation stress ratio. Under the condition of the same consolidation stress ratio but different stress history, the amount of final compression of the overconsolidated saturated clay was smaller than that of the normally consolidated saturated clay. Besides, the stress difference σdv between consolidation pressure σ and gravity stress σ c z was fitted to the amount of the final sample’s compression, and a good linear relationship between the stress difference σ d v and the amount of the final sample’s compression under each consolidation pressure was obtained. The results showed that it is necessary to consider the influence of consolidation stress ratio and stress history simultaneously on 1-D consolidation permeability of saturated clay. Meanwhile, it can accurately predict the amount of the final sample’s compression after knowing the gravity stress. Moreover, a model prediction analysis was conducted on the saturated clay and recommended to use the modified Kozeny-Carman’s equation to predict the permeability coefficient of Luochuan saturated clay during one-dimensional consolidation.

Al86Ni8Co1La1Y2Gd2 amorphous coatings were prepared using cold gas kinetic spray technology. The results show that Al86Ni8Co1La1Y2Gd2 amorphous coatings are achieved with the porosity about 3.2%, thickness about 893 μm, the amount of amorphous phase about 82.5%, the hardness about 300HV0.2. The corrosion potential and anti-corrosion life of 7075 T6 alloy aluminum are about −0.78 V and 72 h, respectively. The electrochemical analysis and neutral salt spray are about −0.69 V corrosion potential and 274 h anti-corrosion life for amorphous Al-based coatings, respectively. Therefore, the life of the Al-based amorphous coatings is about 3.8 times that of 7075 T6 aluminum alloy. Besides, the failure mechanism was analyzed using TEM in this investigation. In a word, Al86Ni8Co1La1Y2Gd2 coatings keep dense structure, high amorphous content, favorable amorphous phase stabilizing ability and longer anti-corrosion life. That is, Al86Ni8Co1La1Y2Gd2 coatings have better comprehensive properties. Therefore, these findings indicate that the present Al86Ni8Co1La1Y2Gd2 amorphous coatings prepared using cold gas kinetic spray technique can protect aluminum alloy very well and they can be considered to be used in aviation field.

Lutetium aluminium garnet (LuAG) ceramics as host materials has been widely used in lighting, laser, displaying and scintillators after doping different rare earth ions. Right selection of raw powder and controlling its characteristics during the preparation can greatly improve the optical quality of transparent ceramics. In this paper, the influence of different pretreatment temperatures of commercial Lu2O3 powders in oxygen atmosphere on solid state sintering of LuAG ceramics was systematically investigated. The pretreatment gradually decreased the specific surface area of Lu2O3 powders and greatly removed the absorbed impurities, which seriously deteriorated the optical quality before. The mean particle size increased from 4.53 to 5.66 μm, and the in-line transmittance of samples (Thickness = 2 mm) at 1064 nm was 68.4% for the pretreated Lu2O3 powder at 1000 °C without any sintering additives. Further increase of pretreatment temperature would lead to the coarsening of Lu2O3 powders and the decrease of sintering activity, which finally resulted in a large number of micro pores in LuAG ceramics. These results revealed that the pretreatment of Lu2O3 powders has prodigious impact on the optical quality of LuAG transparent ceramics, and the adsorbed materials should be removed as much as possible for their applications in lasers or lighting.

Impinging jet fire of high exit momentum is frequently reported to induce the domino effect in industry fires. Less literature is available for the flame extension area and temperature distribution over a vertical plate impinged by the horizontal jet flame. Thus, this paper conducts a systematic experiment to reveal the effect of nozzle exit velocity, exit diameter and exit-plate spacing on the horizontally impinging jet fire. Experimental observation shows the evolution of flame pattern and color with an increase of exit velocity and a decrease of exit-plate spacing. The flame extension area induced by the horizontal jet flame impingement was measured by a novel method that combines the picture processing technique and the thermal imaging technique. By physical analysis, a new correlation coupling the turbulent Karlovitz stretch factor and the ratio of nozzle exit diameter to exit-plate spacing, was developed for the flame extension area of both horizontally and vertically impinging jet fire. The variation of maximum temperature in the impinging zone with the exit-plate spacing still fits the classic correlation of centerline temperature in the continuous and intermittent flames. However, the horizontally impinging jet fire plume holds a shorter intermittent flame region due to the flame upward bending. It is found that the temperature profile holds a big difference in the upward and downward directions along the vertical plate. A new uniform correlation, with the plume radius as the characteristic length scale, is proposed to well collapse all the temperature data in the impinging zone.

With the evolution of power electronic system to miniaturization and integration, dielectric capacitors are extensively studied in electric power systems such as electron beam and direction energy weapons owing to outstanding energy storage density and low loss. In this work, Pb0.97La0.02ZrO3 (PLZ) films were deposited on LaNiO3 (LNO)/Pt and LNO electrodes using sol-gel method, respectively. High spontaneous polarization (Ps ~ 91.3 μC cm−2) and low remanent polarization (Pr ~ 7.3 μC cm−2) can be obtained from PLZ/LNO/Pt/TiO2/SiO2/Si with energy storage density up to 25.4 J cm−3, which could be explained by good ohmic contact between films and composite electrodes. Besides, recoverable energy storage of films exhibits outstanding temperature stability (25.9–25.3 J cm−3) over -60 - 20 °C. These results suggest that LNO/Pt composite electrodes can be used to optimize PLZ films properties, which could be considered as a valid way for developing wide temperature range energy-storage capacitors.

Elaborating a high performance and thermostable LED lighting source based on YAG:Ce ceramic photo-convertor is mainstream for outdoor lighting. However, it still suffers from narrow luminous angle using traditional molding method. In this paper, high quality YAG:Ce tubular ceramic was prepared using a low pressure injection molding (LPIM) and vacuum sintering. The results showed the viscosity of suspension with 75.0 wt.% solid content was as low as 190.34 Pa·s at the shear rate of 100 s−1, and the molding pressure and holding time were adopted to be 0.8 MPa and 8 s, respectively. Impressively, the final YAG:Ce ceramic (double polished to 1.0 mm) with relatively high in-line transmittance of 72.5 % was produced. Furthermore, constructing the YAG:Ce ceramic tube with the hexahedral “columnar blue chip arrays’’, a 4π white light emission with a luminous efficiency of 126.46 lm/W and low correlated-color temperature of 4333 K and was attained.

Yttrium aluminum garnet (YAG) transparent ceramics are an attractive material for solid-state laser, optical and high temperature structural applications because of their prominent advantages. However, it is difficult to achieve the high-quality ceramics by acrylamide (AM) aqueous gelcasting due to the inhomogeneous of gel body induced by traditional methods of “catalyst + initiator” or “initiator + heating”. In this work, a series of gel induction contrast experiments were designed to explore a novel gelcasting induction method. With different gelation process, the SEM of surfaces and fracture surfaces and as-fabricated ceramics quality, it was found the effectiveness of the novel gel induction method “vacuum defoaming + initiator”. The method had the ability to improve the uniformity of the gel body by regulating the form of energy injection and having enough time for the stirring of initiator. In addition, the decreasing residual organics would result in contributing to the subsequent debinding and ceramic quality improvement. Therefore, the “vacuum defoaming + initiator” was regarded as an effective induction method to eliminate defect and to achieve the in-line transmittance of as-fabricated YAG ceramic with excellent optical quality at 1064 nm reached 82.8%. This work greatly promotes the application of gelcasting in YAG transparent ceramics.

Large-sized Nd: YAG laser transparent ceramics have great potential as the gain medium in the high-power laser devices for military and industry due to the superior thermal conductivity and optical property. However, some defects of large-sized ceramics such as deformation and fracture sometimes occur during sintering process. The real-time characterization of thermodynamic properties in the high-temperature sintering (> 1750 °C) is very difficult. It leads to unclear reasons of sintering defect. Therefore, in this work, combined with sintering systems and experiments, the thermal distribution, stress, and strain of sintered bodies were analyzed by finite element method (FEM) with non-uniform density and temperature field assumptions. For Φ15 × 220 mm ceramic rod, the order of factors affecting the thermal stress was the temperature inhomogeneous (28.29 MPa) > density gradient (15.34 MPa) > the cooling rate (11.7 MPa). The order of factors affecting the strain was also the same: inhomogeneous temperature in furnace cavity > uneven density > the cooling rate under our sintering system, and the maximum deformation was at the middle part of ceramic rod. In addition, the fracture at random position could be considered as the microcrack inside the green body. Therefore, the quality of green body directly affected the formation of ceramic defects in later sintering. These results are crucial for controlling the defects in large-sized laser ceramics preparation.

The development of clean and sustainable energy depends largely on electrocatalysis-driven technologies. Because of this, tremendous efforts have been devoted to the search for efficient electrocatalysts to reduce the overpotential and increase the selectivity of electrochemical reactions. Of the various approaches, electrochemical tuning is seen as a promising technique to controllably tune the properties of catalytic materials under mild conditions. Based on this, this review will present representative electrochemical tuning methodologies involving insertion and conversion reactions in batteries as well as in situ electrode modulation during electrocatalysis processes. This review will first provide an introduction of electrochemical tuning strategies from the perspective of reactions and devices. Subsequently, this review will present comprehensive discussions on recent advancements in the modulation of various electrocatalyst properties, including electronic structure, crystalline phase, lattice strain and dimensional size, all of which significantly impact corresponding intrinsic activity and active site exposure. This review will also highlight the merits, challenges and issues of electrochemical tuning and propose promising directions in the exploration of corresponding methods in the design and enhancement of electrocatalysts for future energy applications.

Electronic packaging products are often subjected to reliability evaluation, Sn–Pb solder is widely used in high-reliability military products due to its excellent soldering performance. Sn–36Pb–2Ag eutectic solder joints were subjected to aging experiments at 75 °C, 100 °C, 125 °C, and 150 °C for 100 h, 250 h, 500 h, and 1000 h, respectively. Continuous Cu3Sn and (Au, Cu)6Sn5 compounds were formed on the printed circuit board (PCB) substrate side after aging experiments, and continuous (Au, Ni)Sn4 and (Au, Ni)3Sn4 compounds were formed on the electronic component side. In addition, the Pb–rich phase on the IMC layer side increased with the increase in aging time and aging temperature. Thus, the mechanical properties of the solder joints seriously reduced, and the push force of the fractured solder joint measured in the push–pull force experiment was reduced from approximately 85 N (125 °C–500 h) to approximately 42 N (150 °C–1000 h). The fracture mode of solder joint under 150 °C–1000 h aging conditions was brittle. Furthermore, the diffusion coefficient and activation energy of the Cu3Sn phase and (Au, Cu)6Sn5 phase on the PCB substrate side were calculated.

Removing interferences such as Ce on Nd isotopes during column chemistry is hard to achieve due to their similar properties. In this study, we established a simple but efficient Nd separation technique with the perfect separation of Nd from Ce and nearly 100% Nd yield using the TODGA resin (50–100 μm, Eichrom, USA) after actual measurements. All samples used here through the Nd separation technique have Ce/Nd ratios less than 0.003. The whole procedure takes about 10 h. The stable Nd isotopes were measured by MC-ICP-MS and calibrated with standard-sample-standard bracketing (SSB) combined Eu internal normalization. The potential influences of Eu and Ce on stable Nd isotopic analysis were strictly evaluated. The long-term analyses of the JNdi-1 standard produced a total average δ142/144Nd of 0.000 ± 0.029‰ (2SD, n = 210), δ145/144Nd of 0.000 ± 0.029‰ (2SD, n = 210), and δ146/144Nd of 0.000 ± 0.027‰ (2SD, n = 210). Two pure Nd standards, La Jolla and Nd-GIG, produced δ146/144Nd values (means ± 2SD, n = 20) of −0.227 ± 0.030‰ and 0.226 ± 0.021‰, respectively. δ146/144Nd (means ± 2SD, n = 20) of seven geological reference materials (BCR-1, BHVO-2, AGV-2, GSP-2, NOD-P-1, NOD-A-1, and GBW07249) were also reported. The reproducibility of δ146/144Nd was better than 0.030‰. These results are in good agreement with the published DS-TIMS methods. In addition, our method also allows the concurrent determination of the radiogenic 143Nd/144Nd ratio. All the 143Nd/144Nd ratios of these samples are identical with the preferred values published in the GeoReM Database. These results indicated that the method of Nd isotopic analysis established here can simultaneously measure high-precision δ142/144Nd, δ145/144Nd, δ146/144Nd, and radiogenic 143Nd/144Nd ratio for geological materials.

Mid-infrared (MIR) radiation has a wide range of applications in military, environmental monitoring, and medical treatment. Black phosphorus (BP), an emerging van der Waals (vdW) layered material, shows high carrier mobility, decent optoelectronic properties, and good compatibility with silicon technologies. In 2019, the MIR photoluminescence properties of thin-film black phosphorus were uncovered. Further studies show that the MIR photoluminescence properties can be widely tuned by temperature, thickness and external electric field, indicating BP as a promising MIR light-emitting material candidate. Optically-driven MIR lasers have been also achieved through coupling thin-film BP with well-designed micro-cavities. In addition, the realization of electrically-driven MIR light-emitting devices of BP-based vdW heterojunction further paves the way of MIR light-emitting applications in the BP-silicon hybrid on-chip systems with low cost and high integration scale. Herein, we review the recent research progress of BP MIR light-emitting properties, including the thickness-, temperature-, electric-field-dependent MIR light-emitting properties, and BP-based MIR light-emitting devices, such as MIR lasers and light-emitting diodes. The coupling between BP MIR light-emitting devices and silicon waveguide will also be discussed.

In this study, a high-activity Zn–Co double metal cyanide complex was synthesized and used to catalyze the ternary polymerization of carbon dioxide, propylene oxide, and itaconic anhydride to produce a new class of polypropylene carbonates characterized by excellent performance and low ether content. The number average molecular weight of the terpolymer was as high as 2.14 × 105 g·mol−1, and the polydispersity index was as high as 1.58. In the case of PPCIAn3, the 5% weight loss temperature increased by 70°C, the total weight loss temperature increased by 100°C, the tensile strength increased by 6.6 MPa, and the elongation at break decreased to 14.5% with respect to traditional polypropylene carbonate. The apparent efficiency of the catalyst was as high as 45.79 gpolymer/gcatalyst, indicating its high catalytic activity. 1H-NMR spectrometry, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, and in situ Fourier-transform infrared spectroscopy were used to characterize the polymerization process and the structural properties of the obtained terpolymers.

A new three-dimensional (3-D) inorganic metal-oxygen network vanadoborate Na3H10[Ni(H2O)2(VO)6(B10O22)2]·NH4·19H2O (1) constructed from lantern-type {(VO)6(B10O22)2} clusters, NaO6 polyhedra and NiO6 octahedra, was successfully synthesized by a hydrothermal method. In the structure, the {V6B20} clusters are linked together through NiO6 octahedral bridges, resulting in 1-D chains along the c-axis. The 1-D chains are further connected by NaO6 polyhedra to give rise to a 3-D open-framework structure. Furthermore, lots of NH4+ and H2O molecules are accommodated in the void of the structure, and may interact with the [V6B20] system via N-HO, O-HO hydrogen bonds, constructing a complex hydrogen-bonding network system. Strikingly, compound 1 exhibited a high proton conductivity of 3.22 × 10-3 S cm-1 at 50 °C under 100% RH with an activation energy of 1.66 eV.

Pulse microwave excite thermoacoustic (TA) Shockwave to destroy tumor cells in situ. This has promising applications for precise tumor therapy in deep tissue. Nanoparticle (NP) with high microwave-acoustic conversion is the key to enhance the efficiency of therapy. In this study, we firstly developed defect-rich titanium nitride nanoparticles (TiN NPs) for pulse microwave excited thermoacoustic (MTA) therapy. Due to a large number of local structural defects and charge carriers, TiN NPs exhibit excellent electromagnetic absorption through the dual mechanisms of dielectric loss and resistive loss. With pulsed microwave irradiation, it efficiently converts the microwave energy into shockwave via thermocavitation effect, achieving localized mechanical damage of mitochondria in the tumor cell and yielding a precise antitumor effect. In addition to the therapeutic function, the NP-mediated TA process also generates images that provide valuable information, including tumor size, shape, and location for treatment planning and monitoring. The experimental results showed that the TiN NPs could be efficiently accumulated in the tumor via intravenous infusion. With the deep tissue penetration characteristics of microwave, the proposed TiN-mediated MTA therapy effectively and precisely cures tumors in deep tissue without any detectable side effects. The results indicated that defect-rich TiN NPs are promising candidates for tumor therapy.

Lithium-ion capacitors (LICs) are hybrid energy storage devices with a capacitor-type cathode and battery-type anode, which bridge the gap between conventional high-energy lithium-ion batteries and...

In this work, the water vapor corrosion behaviors of plasma sprayed ytterbium silicate coatings with different contents of Yb2O3, Yb2SiO5 and Yb2Si2O7 phases were evaluated at 1400oC for 100–300 h and the influence of phase compositions on the corrosion behaviors was analyzed. The results showed that severe corrosion took place in the Yb2Si2O7-rich coating with a porous reacted layer with a thickness about 20 μm after 300 h corrosion. The Yb2O3 phase in the Yb2O3-rich coatings volatilized, lefting a relatively dense reacted layer with a thickness about 5–6 μm after the same corrosion time. A layer composed of Yb2SiO5 was formed on the surface of all the corroded ytterbium silicate coatings. This study may provide theoretical basis for selecting rare-earth silicate environmental barrier coatings (EBCs) with excellent performance.

Tensile failure (spalling or slabbing) often occurs on the sidewall of deep tunnel, which is closely related to the coupled stress state of deep rock mass under high pre-static load and dynamic disturbance. To reveal the mechanism of rock tensile failure caused by this coupled stress mode, the Brazilian disc tests were carried on red sandstone under high pre-static load induced by dynamic disturbance. Based on the pure static tensile fracture load of red sandstone specimen, two static load levels (80% and 90% of the pure static tensile fracture load) were selected as the initial high pre-static loading state, and then the dynamic disturbance load was applied until the rock specimen was destroyed. The dynamic disturbance loading mode adopted a sinusoidal wave (sine-wave) load, and the loading wave amplitude was 20% and 10% of the pure static tensile fracture load, respectively. The dynamic disturbance frequencies were set to 1, 10, 20, 30, 40, and 50 Hz. The results show that the tensile failure strength and peak displacement of red sandstone specimens under coupled load actions are lower than those under pure static tensile load, and both parameters decrease significantly with the increase of dynamic disturbance frequency. With the increase of dynamic disturbance frequency, the decrease range of tensile strength of red sandstone increased from 3.3% to 9.4% when the pre-static load level is 80%. While when the pre-static load level is 90%, the decrease range will increase from 7.4% to 11.6%. This weakening effect of tensile strength shows that the deep surrounding rock is more likely to fail under the coupled load actions of pre-static load and dynamic disturbance. In this tensile failure mechanism of the deep surrounding rock, the stress environment of deep sidewall rock determines that the failure mode of rock is a tensile failure, the pre-static load level dominates the tensile failure strength of surrounding rock, and dynamic disturbance promotes the strength-weakening effect and affects the weakening range.

Lead-free double perovskites (DPs) with excellent moisture, light, and heat stability have been explored as alternatives to toxic lead halide perovskite (APbX3) (A for monovalent cation and X for Cl, Br, or I). However, the bandgaps of the current DPs are generally larger and either indirect or direct forbidden, which leads to weak visible light absorption and limitation for photovoltaic and other optoelectronic applications. Herein, we demonstrate the first synthesis of Cu2+-doped Cs2AgInCl6 double perovskite nanocrystals via a facile hot-injection solution approach. The electronic bandgap can be dramatically tuned from ∼3.60 eV (Cs2AgInCl6, parent) to ∼2.19 eV (Cu2+-doped Cs2AgInCl6) by varying the Cu2+ doping amount. We conclude that the decrease of bandgap is attributed to the overlap of the Ag-d/In-p/Cl-p orbitals and the Cu-3d orbitals in the valence band. The wide tunability of the optical and electronic properties makes Cu2+-Doped Cs2AgInCl6 DP NCs promising candidates for future optoelectronic device applications.

In this work, the structural and magnetic transitions of Heusler alloy Ni50Mn34In14Ga2 have been carefully studied through measurements of heat flow and magnetization under DC and AC magnetic fields. This alloy undergoes the transition sequence of spin-glassy martensite (SPM) → ferromagnetic austenite (FA) → paramagnetic austenite at ∼225 and ∼305 K, respectively, during heating. Splitting of zero-field-cooling (ZFC)/field-cooling (FC) curves in martensite is caused by the slowdown dynamics of spin glass as evidenced by frequency dispersion and aging effects. The development of a spin-glass state is believed to be the result of strain relaxation and interaction of ferroelastic twin walls in the martensite. The magnetocaloric effect (MCE) at the SPM-FA transition was then measured using indirect, quasi-direct, and direct methods. The MCE magnitudes are controlled by the entropy changes associated with the first-order martensite transition and magnetic ordering of austenite under the magnetic field. The existence of a spin-glass state in martensite can also improve the reversibility of the magnetostructural transitions, which is beneficial for the improvement of the reversibility of associated MCE. These results provide an in-depth understanding of the transitions and magnetic properties of the Ni-Mn Heusler alloys and suggest that the MCE at the first-order magnetostructural transitions estimated solely using indirect methods may need some revision.

By adding different amounts of rare earth element Y and Gd in Al86Ni8Co1La5, aluminum amorphous ribbon samples were prepared using single roller melt-spinning under 2 different roller speeds. Then X-ray diffraction (XRD), transmission electron microscope (TEM) and differential scanning calorimetry (DSC) were adopted to study the effect of rare earth element Y and Gd additions on phase structure, forming ability and thermal stability of Al86Ni8Co1La5 alloy. The results show that the better chemical composite is Al86Ni8Co1La1Y2Gd2, which can form a whole amorphous strip when the roller speed is 3 m/s. After the better chemical composition is confirmed, the Al-based amorphous powder is produced using gas atomization and its properties are also validated using cold spray technique. The thickness, porosity and amorphous amount of coatings is about 600 μm, 0.5% and 80.2% (CS–C), respectively. These findings indicate that Al86Ni8Co1La1Y2Gd2 amorphous powder can be used as raw materials for cold spray technique.

Aiming at the plastic shrinkage cracking of cement mortar, the constitutive equations of it in laboratory were established by testing plastic tensile strength, plastic capillary shrinkage stress and water loss evaporation rate of mortar under different composition parameters, environmental parameters, initial structural parameters and constraints condition parameters. And the early warning system of it was explored. The results showed that the seven-element constitutive equation of plain mortar and the nine-element constitutive equation of mortar with polyvinyl alcohol (PVA) fiber can effectively predict the plastic shrinkage cracking state of mortar outdoors. An early warning system for it was initially established.

Nitriding can improve the surface hardness and wear resistance of metals, and rare earths can speed up this process. To study the mechanism of rare earths promoting salt bath nitriding, GX-8 steel ...

Electrostatic energy-storage capacitors, with their ultrahigh storage density and high temperature stability, have been receiving increasing attention of late for their ability to meet the critical requirements of pulsed power devices in low-consumption systems. In such a context, this work reports on the successful production of anti-ferroelectric (AFE) thin films with excellent energy storage performance under a relatively low electric field. In particular, La-doped PbZrO3 thin films were fabricated using a sol-gel method, yielding a recoverable energy storage density of 34.87 J cm−3 with an efficiency of 59.23% at room temperature under the electric field of ~800 kV cm−1. The temperature dependence of the energy storage property was demonstrated from room temperature to 210°C, indicating a stable density variation between 34.87 and 27.98 J cm−3. The films also exhibited excellent anti-fatigue property (endurance of up to 3×109 cycles and the recoverable energy storage density varied from 39.78 to 29.32 J cm−3 combined with an efficiency of 61.03%–44.95% under the test frequencies from 10 to 5000 Hz). All results were obtained using compact films with a high polarization ( P max) of approximately 103.7 μC cm−2 and low remnant polarization ( P r~7 μC cm−2), which was owing to the combination of LaNiO3 buffer layers and vacancies at Pb sites. These results illustrate the great potential of pulsed power devices in low-consumption systems operating in a wide range of temperatures and long-term operations.

The exfoliation corrosion behaviour of 2024 aluminium alloy was investigated through exfoliation corrosion test, together with synchrotron radiation X-ray computed tomography (SR-CT) to achieve the 3D segmentation of precipitated phases, cracks and corrosion products. The results demonstrate that aging treatment has a significant effect on the distribution of the precipitated phases in the 2024-T4 aluminium alloy, and the precipitated phases continuously distributed along the grain boundary would lead to intergranular corrosion (IGC) which is easily evolved into exfoliation corrosion. In the 2024-T2 aluminium alloy, the longest crack was found to locate at the boundary between the inner grains structure and outer peripheral coarse grain (PCG) structure, which indicates that the corrosion is attributed to electrochemical property difference of two structures.

β-TCP has excellent biodegradability and bioabsorption properties, and is regarded as an ideal hard tissue repair material. In the present study, 3D printing β-TCP green bodies was realized using the stereo lithography apparatus (SLA) technology. The effects of the KH-560 dispersant and solid loading on the slurry properties were investigated systematically. The optimized KH-560 addition amount and the solid loading of the slurry were 2.0 wt% and 48 wt%, respectively, and the corresponding slurry for the subsequent SLA 3D printing exhibited good fluidity, uniform dispersion and good stability. The sintering schedule of the printed β-TCP green bodies was optimized by the DSC-TG analysis. By sintering the green bodies at 1050 °C for 8 h, high quality β-TCP bioceramics without crack or deformation were fabricated. It was found that increasing the solid loading of the slurry would decrease the porosity while reducing the shrinkage degree of the β-TCP ceramics. However, the slurry could hardly be printed when its solid loading was higher than 50 wt%.

A 5-layer laminated metal composite composed of ultrahigh-strength maraging steel and ductile 316L stainless steel was fabricated by hot pressing in vacuum and post-heat treatment. Microstructure characterization on hierarchical structure of the composite before and after heat treatment was made by optical microscopy, scanning electron microscopy and electron back-scattered diffraction technique, respectively. Meanwhile, the difference of mechanical performance on both sides of the interface was characterized by nano-hardness testing. Uniaxial tensile test showed that superior interfacial bonding was achieved due to the micro-‘bite’ structure between the two steels without obvious defects or oxides at the interface and with coordinated deformation of the two components. Thus, a laminated metal composite consisting of two different constituents with extreme difference in strength can be well fabricated.

The in-depth investigation of hydrogen behaviors in Pu-oxide overlayers (mainly PuO2 and α-Pu2O3) is critical for modeling the complex induction period of Pu hydriding. Within density functional theory (DFT) + U + D3 schemes, our systematic first-principles calculations and ab initio thermodynamic evaluations reveal that the hydrogen incorporation, dissolution behaviors, and diffusion mechanism in PuO2 are quite different from those in α-Pu2O3, among which the highly endothermic incorporation and dissolution of hydrogen are the primary hydrogen resistance mechanism of PuO2. Since its difficult recombination, atomic H is the preferred existence state in PuO2, but H will recombine spontaneously in α-Pu2O3. In PuO2, H diffusion is always clinging to O anions, whereas in α-Pu2O3, H2 prefers to migrate along O vacancies with higher barriers. H dissolution in intact PuO2 is very difficult, which can only be driven by extremely high pressure PH2 and temperature. Based on a series of theoretical studies, we conclude that the main interactions between hydrogen and Pu-oxide overlayers are not involved with chemical reactions, and intact PuO2 can effectively inhibit hydrogen permeation.

Secondary electrocaloric effect (ECE) arising from piezoelectricity combined with crystal thermal expansion was often overlooked in ECE studies of ferroelectric ceramics. This work mainly evaluated the primary ECE (ΔTECE) and secondary ECE (∆T2) of eco-friendly BaSnxTi1-xO3 (BSnT100x, 0