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This letter proposes a general formula to determine the amount of compound required to produce water–oil-based phantoms that can emulate the electrical properties of a specific body tissue at microwave frequencies. The existing process to produce such a phantom usually involves mixing together a number of different materials, where the proportion of each compound needs to be known a priori to reproduce the dielectric properties of a specific tissue. In this letter, we first investigate the dielectric variation of the mixture by changing the proportion of each compound over a wide frequency band. By utilizing Lichtenecker's logarithmic mixture formula, the gradient descent iterative optimization method is applied to train the relations obtained, and a formula that determines the amount of each compound required to produce a phantom given a specific tissue type is derived. The formula is verified by constructing representative tissues of the human head, with the durability and fidelity of the produced phantom also analyzed.

The shortage of water has become a serious problem in the development of the steel industry in China. Therefore,it is important for research to be done in environment management, estimating the potential improvement of steel industry. This study propose an improved water footprint model of steel production based on the water footprint network methodology and the life cycle assessment framework. The result shows that the water footprint of steel production is 41.09m3/t, which requires larger amounts of direct blue water. The case of China highlights the relevance of clean production, energy efficiency measures, and grading utilization on reducing the water footprint of steel production.

Based on the analysis of the development situation of China’s cement industry and the BCG Matrix method, this paper classifies and screens 31 energy-saving technologies in China's cement production, and puts forward guiding suggestions for the application of energy-saving technologies for cement enterprises. The screening results show that the “Energy-efficient powder separation technology” and “New low-calcium cement clinker and production technology” are “double-high” technologies with excellent on both screening indicators. The investment energy saving rates are 17.5 tce/10,000 yuan (tons of standard coal equivalent per 10,000 yuan) and 10 tce/10,000 yuan. The promotion ratio increments are 35% and 25%. “Cement clinker energy-saving nitrogen reduction firing technology”, “Fan drive mode adopts high voltage frequency conversion speed control technology”, “Pure low temperature waste heat power generation technology for cement kiln” are “single-high” technologies with excellent on one of screening indicators. The investment energy saving rates are 0.3tce/10,000 yuan, 4.1tce/10,000 yuan, 3.9tce/10,000 yuan respectively. The promotion ratio increments are 19%, 35%, 31.5% respectively.

As an important tool for water resource environmental impact assessment, the application of water footprint assessment method in copper production process is conducive to more accurate assessment of water resource environmental impact in copper production process. The water footprint assessment method released by the Water Footprint Network was used to study the water footprint of the production process of cathode copper products produced by pyrometallurgy. It was found that the water footprint of 1 ton of copper produced by pyrometallurgy was 242m3, of which the blue water footprint accounted for 60%, the grey water footprint accounted for 40%. The direct water footprint accounted for 67% and the indirect water footprint accounted for 33%. The characteristics of water footprint contribution at each process were compared, which provided data support and reference for enterprises to better understand the water resource environmental impact of copper by pyrometallurgy and to choose the water resource utilization mode with their own production characteristics.

The ISO14046 water footprint evaluation method was used in this study to calculate the water shortage footprint and water degradation footprint in plate glass production, in order to improve the water efficiency and management level in the production process of plate glass in China. A certain enterprise in Hebei province was selected for investigation in 2018. The results show that the water shortage footprint generated by the production of flat glass was 0.435 m3H2Oeq/weight box. The proportion at raw material production stage was the largest, being 86%, so the water consumption control in raw material mining and the circulating water system should be strengthened and improved to reduce the fresh water consumption. Water degradation footprint in flat glass industry mainly consisted of eutrophication and acidification footprints. The eutrophication footprint was calculated as 0.027 kgNO3-eq/weight box, and water acidification footprint was 0.271 kgSO2eq/weight box. The largest proportion occurred at flat glass production stage. It should be paid attention at this stage, to update the relatively clean production equipments and add the waste gas processing steps to reduce pollution discharge.

Low cost and high performance are the pursuing goals of the light-emitting diode (LED) packaging. The phosphor layer configuration of LEDs significantly influences optical performances. In this study, thermalcapillary flow was introduced in the phosphor coating by the blue laser local irradiation. It has been demonstrated to successfully manipulate the phosphor particle distributions. In the phosphor dispensing coating, a centripetally concentrated particle distribution was realized and resulted in high angular color uniformity (ACU) and low-cost manufacture. Its angular correlated color temperature (CCT) deviation was reduced by more than 65%, compared to the traditional phosphor dispensing coating. Besides, the phosphor amount is saved by about 12%. The mechanism of ACU enhancement is analyzed. The realized phosphor particle distribution can inspire further development of the optimized phosphor layer configuration.

Inorganic metal halide perovskite quantum dots (QDs) have emerged as a new class of solution-processable semiconductor materials for next-generation displays. However, such QDs commonly suffer from surface defects, resulting in low photoluminescence quantum yields (PLQYs) and inefficient charge carrier transport in perovskite QD based light-emitting diodes (perovskite QD-based LEDs). Herein, we propose an effective strategy of introducing gallium (Ga) cations to passivate surface defects in the CsPbBr3 QDs for the fabrication of bright perovskite QD-based LEDs. Partial Ga cations in the CsPbBr3 QD surfaces are beneficial for their surface defect passivation and their crystalline quality. Correspondingly, the radiative recombination and carrier mobility are greatly enhanced compared with the pristine ones. The PLQY of CsPbBr3 QDs passivated with 40% Ga cations is increased from 60.2% to 86.7%. The corresponding perovskite QD-based LEDs exhibit a maximum brightness of 11 777 cd m−2, more than two times higher than that of the pristine QD-derived device. The corresponding operational stability is also greatly enhanced relative to the pristine-derived device. The proposed Ga cation passivation strategy paves the way toward the fabrication of highly efficient perovskite QD-based LEDs for applications such as perovskite QD-based LED displays and light conversion based micro-LED displays.

Controllable liquid transportation is of great value in various practical applications. Here, we experimentally demonstrate a method of actuating high-speed droplet transport with large manipulation controllability on lubricated surfaces using a corona discharge generated by a simple needle-plate electrode configuration. Linear motion of droplets is realized with a maximum velocity of 30 mm/s. Factors affecting the velocity of these droplets are analyzed systematically, and the mechanism of droplet transport is explained. The lubrication film flow induced by charge deposition is shown to be the dominating factor in the droplet manipulation controllability. The new method presented here opens a new path of high-performance manipulation of liquid droplets by controlling the lubrication liquid film flow with charge deposition.

The effects of the white-light X-ray and 170-keV proton beam irradiation on the electrical and optical characteristics of the InGaN/GaN multiple quantum wells (MQWs) light-emitting diodes (LEDs) are analyzed and compared. Different from the negative effects of the proton irradiation, the X-ray irradiation shows positive effects on the LEDs’ performance. In detail, after the 100 Mrad(Si) X-ray irradiation, the p-n junction resistance decreases from the original 2.51 to $2.08~\Omega $ , the light output power increases from 170 to 203 mW (at a forward voltage of 3.2 V), and the maximal external quantum efficiency (EQE) increases from 56.7% to 61.8%. Based on the ABC model fittings, both the Shockley–Read–Hall recombination rate and the radiative recombination rate in the MQWs are improved by the X-ray irradiation. The Hall effect measurements reveal the chemical bond breaking of the Mg-H complex in the p-type GaN. Therefore, the improvement of the LED by the X-ray irradiation should be caused by the chemical bond variations of the defect-related complex in the MQWs and the Mg-H complex in the p-type GaN.

Influences of 170-keV protons beam irradiation on the static and dynamic properties of blue light InGaN/GaN multiple quantum wells (MQWs) microlight-emitting diodes (Micro-LEDs) were investigated. It was interesting to find out that, although threshold voltage and light output power of Micro-LEDs deteriorated after proton irradiation, a 3-dB bandwidth was greatly improved. In quantitative terms, at the forward current density of 1 kA/cm2, 3-dB bandwidth increased from original 7.34 to 119.74 MHz when Micro-LED exposed to proton beam with the fluence of $5\times 10^{14}$ p/cm2. Based on the frequency response data analysis, differential carrier lifetimes of Micro-LEDs, including Shockley–Read–Hall (SRH) lifetime and differential radiation recombination lifetime, were compared. The results pointed out that both SRH and recombination lifetimes became shorter after proton irradiation, indicating that competition between the nonradiative and radiative recombination processes was enhanced by proton beam. To reveal the origination of the 3-dB bandwidth improvement, photoluminescence (PL) and time-resolved PL (TRPL) spectrums of Micro-LEDs were measured. MQWs’ PL spectrum with a peak wavelength of 450 nm was observed and its intensity decreased as proton fluence increasing. Meanwhile, a PL peak at 550 nm, which was well known as defect-related PL spectrum, was enhanced by proton irradiation, especially at a proton fluence of $5\times 10^{13}$ and $5\times 10^{14}$ p/cm2, proving the increase of defects in epitaxial thin films as proton fluence increasing. In the TRPL experimental study, the nonradiative recombination lifetime decreased with proton fluence, which was consistent with the results analyzed by frequency response. Overall, the improvement of 3-dB bandwidth could be mainly attributed to the decrease of carrier lifetime in MQWs, which were caused by the generation of defects due to the atom displacement effect of proton irradiation.

We applied Ba-containing anode (Ni-BaZr0.1Ce0.7Y0.2O3-δ (NiO-BZCY)) to the Nd doped Sm0.15Ce0.85O2−δ(SNDC) electrolyte layer, aiming to solve the electron-leakage problem for CeO2-based electrolyte as well as to use the high conductivity of SNDC and the good interfacial oxygen incorporation. The NiO-BZCY anode not only acts as a catalysis for anode reactions but also offers barium source to form an electron-blocking layer which contains Ba for single cells based on SNDC electrolyte. The high conductivity of SNDC allows a reduction of electrolyte resistance and also provides a better interfacial oxygen-ion incorporation ability compared with the traditional Sm-doped CeO2 (SDC), facilitating the interfacial reactions. As a result, the open circuit voltage and the maximum power density of the cell using SNDC electrolyte exhibits are 1.03 V and 1024 mW/cm2 at 650 °C, which is much higher than that for traditional SDC-based cell even using the same barium-diffusion strategy, which is only 610 mW/cm2 at 650 °C.

In this study, the LCA assessment model of CML was employed to analyze the environmental burden caused by the production of glass substrates, and the evaluation of the environmental performance of five stages of preparation of ingredients, including glass melting, precision clarification, overflow molding and post process, was also conducted. The results show that the global warming potential is the dominant impact category in the comprehensive environmental burden with a normalized value of 4.64×10-14, followed by the acidification potential (2.57×10-14), photochemical oxidation potential (2.82×10-15). And the relative contribution of abiotic depletion potential and human toxicity to the comprehensive environmental burden is rather limited, with the normalized values of 8.31×10-17 and 1.21×10-16, respectively. The single score of environmental impact due to the whole production system is 2.37×10-13, wherein the environmental impact values of the processes of preparation of ingredients, glass melting, precision clarification, overflow molding, and post are 1.07×10-15, 9.10×10-14 (highest), 2.26×10-14, 7.36×10-14, and process 4.90×10-14, respectively. The preparation of the batch, the glass melting, the overflow molding and the post process mainly cause the environmental effects of global warming potential and acidification potential, the cumulative values of which are 1.13×10-13 and 9.01×10-14, respectively. The precision clarification stage mainly causes the environmental effect of acidification potential, the value of which is 2.02×10-14 and much higher than those of other environmental impact categories.

In recent years, the building materials industry in China has made great progress in the R&D of energy conservation, emission reduction and cleaner production technologies, in order to implement sustainable development policy. Life cycle assessment (LCA) is one of the mainstream method to analyze the environmental impact of product during its life cycle, which plays an important role on ecological design of building materials and development of green manufacture technology in recent year. This paper reviewed the LCA studies of building materials. Firstly, the development of China's building materials industry and technical framework of LCA standardized by ISO14040/14044 were introduced. Moreover, the typical LCA case studies of cement, glass, ceramics, wall materials, insulation materials and other building materials were reviewed. At last, some prospects for future research and development in this field were put forward.

A series of cubic perovskite phase BaCoxFe0.7-xZr0.3O3–δ(0.2 ≤ x ≤ 0.5) (BCxFZ) cathode powders are synthesized and their cobalt to iron ratios is varied to explore the best performance on the cell. The experimental results show that as the cobalt content increases, the conductivity and thermal expansion of the cathode samples increase. The density functional theory (DFT) calculation suggests the Oxygen vacancy formation energy continue to decrease but the hydration energy decreases at first and then gets worse. As a result, in BaZr0.3Ce0.5Y0.2O3–δ (BZCY)-based cell applications, the maximum power output of the cell reaches 679 mW/cm2 when the cobalt content is 0.4, and the impedance value is 0.067 Ω cm2 in this ratio.

Frequency microcombs, alternative to mode-locked laser and fiber combs, enable miniature rulers of light for applications including precision metrology, molecular fingerprinting and exoplanet discoveries. To enable frequency ruling functions, microcombs must be stabilized by locking their carrier-envelope offset frequency. So far, the microcomb stabilization remains compounded by the elaborate optics external to the chip, thus evading its scaling benefit. To address this challenge, here we demonstrate a nanophotonic chip solution based on aluminum nitride thin films, which simultaneously offer optical Kerr nonlinearity for generating octave soliton combs and quadratic nonlinearity for enabling heterodyne detection of the offset frequency. The agile dispersion control of crystalline aluminum nitride photonics permits high-fidelity generation of solitons with features including 1.5-octave spectral span, dual dispersive waves, and sub-terahertz repetition rates down to 220 gigahertz. These attractive characteristics, aided by on-chip phase-matched aluminum nitride waveguides, allow the full determination of the offset frequency. Our proof-of-principle demonstration represents an important milestone towards fully integrated self-locked microcombs for portable optical atomic clocks and frequency synthesizers., Though octave soliton microcombs are attractive for on-chip metrology and optical clocks, limitations in existing materials lead to increased chip integration complexity. Here, the authors report access to octave soliton microcombs and self-referencing using aluminium nitride nanophotonic chips.

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Lateral line of fish is an extraordinary mechanosensory organ, which plays a vital role in navigation, object detections, and energy-efficient swimming. The paper presents an artificial lateral line sensor (ALLS) for flow detection by using piezoelectric nanofiber based sensing cantilevers and implemented electronics. Interdigital electrodes were adopted to enable the P(VDF-TrFE)/BTO nanofiber membrane to operate in the thickness (d33) mode. SU-8 pillars, mimicking the cupula of fish lateral line, were fabricated by photolithography. Pre-amplifiers were implemented in the ALLS to reduce the complexity of external testing equipment. The ALLS achieved a velocity detection limit of 1.56 mm/s, which was greatly reduced compared to that of ALLS without preamplifiers.

The ITER high temperature superconducting current lead is a critical component for the magnet system, which has the benefit of reduction in the heat load of the cryogenic system compare with the conventional lead. The current lead is located in the coil terminal box and dry box at the end of the ITER feeder system. As a warm to cold transition section, the current leads feed the huge current from the power supply system into the coils. At the outer surface of the current lead, one layer of a composite insulation is applied to isolate the high voltage potential of the current lead to the ground potential of the environment. The main body of the current lead is that of a long cylinder, but at the cold termination and the cooling inlet, the local geometry is much more irregular. So the insulation wrapping and curing technology of the current lead had to be developed to acquire its uniform mechanical and electrical performance. Now, the multi-stage autoclave curing technology has been qualified in ASIPP and the series ITER current leads are being manufactured based on the qualified procedure. In this paper, the latest insulation progresses for the ITER current lead are introduced, the high voltage testing results as part of the formal qualification are presented and discussed.

To explore the space for further optimization of BaCeO3-based single-phase cathode, series of perovskite materials BaCe0.5Fe0.5-xBixO3-δ (x = 0, 0.1, 0.2, 0.3) as cobalt-free cathodes for proton conducting solid oxide fuel cells are evaluated in this assignment. The influence of the firing temperature on cathode microstructures and the electrochemical performance of fuel cells is evaluated, which states clearly that the best sintering temperature for BaCe0.5Fe0.3Bi0.2O3-δ cathode is 900 °C. Moreover, a special attention is paid to the effect of the Bi doping amount on the phase structure and electrochemical performance. With the cathode BaCe0.5Fe0.3Bi0.2O3-δ, the single cell achieves the polarization resistance of 0.061 Ω cm2 and the maximum power density of 943 mW cm−2 at 700 °C. These encouraging electrochemical results demonstrate that BaCe0.5Fe0.3Bi0.2O3-δ is a promising cobalt-free cathode for proton-conducting solid oxide fuel cells.

A novel cobalt-free cathode Ba0.95Ca0.05Fe0.9-xSnxY0.1O3-δ-SDC (x ≤ 0.1), with various ratios of Sn was proposed. Here, it is applied for proton-conducting solid oxide fuel cells (H-SOFCs), for the first time. Special attention is paid to the exploration of doping amount of Sn effect on the phase structure, electronic conductivity, thermal expansion coefficient (TEC) and electrochemical properties. Ca, Sn and Y co-doped BaFeO3-δ is expected to stabilize a single perovskite lattice structure down to room temperature. TEC data shows that doping of Sn can effectively decrease thermal expansion coefficient, the average thermal expansion coefficient decreases from 17.8 × 10−6 K−1 for Ba0.95Ca0.05Fe0.9Y0.1O3-δ to 12 × 10−6 K−1 for Ba0.95Ca0.05Fe0.8Sn0.1Y0.1O3-δ at the temperature range of room temperature to 850 °C. The single-cell with Ba0.95Ca0.05Fe0.85Sn0.05Y0.1O3-δ-SDC cathode achieves the maximum power density of 949 mW cm−2 at 700 °C. These results demonstrate that Ba0.95Ca0.05Fe0.85Sn0.05Y0.1O3-δ-SDC are promising cathodes for proton-conducting solid oxide fuel cells.

Gd3+ and Cr3+ codoped zinc gallogermanate (ZGGO:Cr3+, Gd3+) nanoparticles were prepared by a hydrothermal method in combination with a subsequent vacuum annealing. It is found that Gd3+ doping not only endows ZGGO:Cr3+ nanoparticles with magnetic property, but also results in the decreased nanoparticle size and the enhanced near infrared (NIR) afterglow intensity. Strikingly, amino group functionalized SiO2 layer coating enabling Gd3+ doped ZGGO:Cr3+ nanoparticles well dispersed in water enhances persistent luminescence which is because of the weakened quenching effect of OH− groups in water. Validation of high-quality bioimaging was demonstrated using the surface functionalized Gd3+ doped ZGGO:Cr3+ nanoparticles dispersed in human serum albumin (HSA). In particular, it is found that the longitudinal relaxivity (7.33 s−1(mM)−1) of Gd3+ doped ZGGO:Cr3+ nanoparticles is higher than that of commercial magnetic resonance imaging (MRI) contrast agent (Gd-DTPA) and it leads to the high-quality in vitro T1-weigthed images.

The sluggish activity of cathode at intermediate-temperature limits commercialization of proton-conducting solid oxide fuel cells (H-SOFCs). In this investigation, a novel cathode of Ba0.95Ca0.05Fe0.85Sn0.05Y0.1O2.9−δF0.1 was successfully developed by co-doping of anion F and cations Ca, Sn, Y. We studied the effect of F−-doping on phase structure, electrical conductivity and electrochemical properties of the cell. Compared with Ba0.95Ca0.05Fe0.85Sn0.05Y0.1O3−δ, F−-doped Ba0.95Ca0.05Fe0.85Sn0.05Y0.1O3−δ exhibited higher conductivity. Composite cathode consisting of Ba0.95Ca0.05Fe0.85Sn0.05Y0.1O2.9−δF0.1 and Sm0.2Ce0.8O2−δ was applied in H-SOFCs with BaZr0.1Ce0.7Y0.2O3−δ electrolyte which achieves an encouraging performance with the maximum power density of 1050 mW cm−2 and polarization resistance of 0.04 Ω cm2 at 700 °C. The result of First-principles calculations based on spin-polarized Density Functional Theory shows that doping of F− reduces the activation energy required for migration of oxygen ions. These results demonstrate that the anions and cations co-doped strategy can provide a new horizon for the cathode in H-SOFCs.

The characteristics of vacancy-type point defects near the surface and inside the AlGaN films were studied by positron annihilation spectroscopy (PAS) and fluorescence spectra. Two types of AlGaN films were grown by varying the growth temperature and the Si doping to maintain the volume of the threading dislocation densities (TDs). The PAS results showed that the point-defect types of the AlGaN films with approximate TDs differed. In the detailed PAS results, the W–S curves of AlGaN films showed two types of point-defect distribution forms. One type was uniform in the AlGaN film, namely, the major point defects inside the bulk and near the surfaces are almost the same as that of the VIII–ON complex, which was the probable candidate. The other type was nonuniform, suggesting that the major point defects were VGa/VAl inside the bulk and VIII–nVN complexes near the surfaces of the AlGaN films. The evolution of the PAS and fluorescence spectra also suggested that a point-defect rearrangement occurred near the...

Ruddlesden-Popper typological (R-P type) layered material La2NiO4 is known for the excellent ionic conductivity and fast oxygen kinetics, but limited by its electronic conductivity as a single-phase cathode for low-temperature proton-conducting solid oxide fuel cells (LT H-SOFC). Cobalt-doping can improve the electro-catalytic capability, accompanied with an increased thermal expansion coefficient (TEC), which would lead to the delamination at the cathode/electrolyte interface. In this assignment, strontium and iron co-doped R-P phase cathode La1·2Sr0·8Ni0·6Fe0·4O4+δ (LSNF), exhibiting fine oxygen conduction, sufficient electronic conductivity and compatible TEC with the electrolyte, is investigated thoroughly. The single cell with LSNF cathode based on BaZr0·1Ce0·7Y0·2O3-δ (BZCY) electrolyte achieves a maximum power density (MPD) of 781 mW cm−2 with the low interfacial polarization resistance (Rp) of 0.078 Ω cm2 at 700 °C. Interestingly, the single cell can also possess an eximious power output of 138.5 mW cm−2 at relatively low temperature of 500 °C. Moreover, the excellent long-term stability with no observable performance degradation for almost 100 h at 600 °C could also indicate that the single-phase R-P layered material LSNF is a preeminent cathode candidate for LT H-SOFC.

In this work, two asymmetric NiO-BaZr0.1Ce0.7Y0.2O3-δ (NiO-BZCY) anode substrates were prepared via the phase-inversion tape casting method for Ce0.8Sm0.2O2-δ (SDC)-based solid oxide fuel cells. The results showed that the anode support structure significantly influenced the electrochemical properties of the cells. The cell supported on the anode substrate consisted of a finger-like layer and a sponge-like layer outputs highest electrochemical performance with a maximum power density of 823 mW cm−2 at 650 °C and shows great superiority over the cell fabricated by a typical dry-pressing method. The excellent performances demonstrate that the phase-inversion tape casting technique is a good strategy in fabricating anode supports for SOFCs, and the anode structure with the relatively dense sponge-like layer as top surface is optimal to construct the complete cell.

A modified superalloy-used heat-resistant adhesive, which can cure at room temperature and provide excellent bonding effect in a wide temperature range from RT to 1000 °C, was prepared from silicone resin as matrix, and Ni, Al, B4C, low-temperature-melting glass powder as additives. After pre-calcination, the bonding strength of adhesive reached 30.1 MPa after 700°C-calcination and maintained above 15.7 MPa during the whole heating process as the mixture of Ni-based intermetallics, heat-resistant ceramic generated and high viscosity glass generated in the adhesive. Without pre-calcination, the bonding strength still kept above 10.5 MPa during test from RT to 900 °C and decreased to 4.3 MPa at 1000 °C.

High-emissivity MoSi2-SiC-Al2O3-SiO2 coating with MoSi2 and SiC as emittance agents, Al2O3 as base skeleton, and silica sol as both dispersive medium of the coating slurry and binder of the coating, was prepared on mullite fibrous insulations via slurry coating and non-firing process. The non-firing coatings were calcined at high temperatures to reveal their reusability after high temperature service. Microstructure, phase composition, interface bonding strength and impact resistance of the non-firing coating and the calcined coatings were investigated comprehensively. Thermal shock resistance, thermal endurance and infrared radiation property of the coatings were studied. The results show that the non-firing coating was dense and flat with all particles bonded together by silica sol; no clear interface existed between the coating and the substrate due to the penetration of the coating slurry; the whole coating was composed of a porous inner layer of about 300 µm in thickness and a top layer of about 100 µm in thickness. The calcined coatings exhibited ideal microstructure with newly formed high temperature phases. Both interface bonding strength and impact resistance of the calcined coatings increased with elevated calcination temperatures, benefited from the good binding effect of silica sol, the gradient structure and the formation of mullite. The coatings remained intact without peeling and spalling after thermal shock tests, and the main defects in the coating surface after thermal shock tests at 1400 °C and 1500 °C were cracks and holes, respectively. The coatings exhibited better long-term thermal endurance at 1400 °C than at 1500 °C, resulted from the weaker oxidation of emittance agents at lower temperature. The emissivity of the non-firing coating at the wavelength range of 3–5 µm and 8–12 µm was as high as 0.9, benefited from the non-firing process, and the emissivity of the calcined coatings were higher than 0.8.

This study analyzed the environmental impacts due to lead production in China, which is the largest producer and consumer of lead in the world, by the method of life cycle assessment (LCA). Based on the Chinese refined lead smelting process, a process-based life cycle assessment model was established to assess the environmental load of lead production system which includes the processes of mining, beneficiation, smelting, electrorefining and transportation. The result shows that the cumulative consumption of electricity and the cumulative emission of green house gases for the production of 1t of refined lead are 1111.93kWh and 2.06E+03kg CO2 eq, respectively. Smelting process is the largest contributor to the environmental impact load, accounting for 51.16% of the total environmental impact. The environmental category of human toxicity potential(HTP), accounting for 35.26% of the total environmental impact, is the largest contributor between different environmental categories to the total environmental impact, followed by metal depletion potential(MDP) and fossil depletion potential(FDP), accounting for 27.94% and 11.80% of the total environmental impact, respectively. Improving the resource efficiencies of the processes of smelting and beneficiation, and using cleaner energy to generate electricity are the key approaches to reduce the overall environmental impact of lead production in China.

Bi and Sn co-doped perovskite BaFe0.8−XSn0.2BiXO3−δ materials have been designed and characterized as a series of new cathodes for proton-conducting solid oxide fuel cells (SOFCs), providing a new life for the traditional BaFeO3-based cathodes. Proton uptake of the cathode increases significantly with bismuth-doping, favoring the application of Bi and Sn co-doped perovskite BaFe0.8−XSn0.2BiXO3−δ materials in proton-conducting SOFCs. The density functional theory (DFT) calculation also suggests that the bismuth-doping leads to a dramatic increase of hydration energy and acceleration of proton migration for the BFS material. The XPS results show that the oxygen reduction reaction (ORR) activity of the cathode is enhanced after bismuth is added, which is consistent with the experimental results of the power density of the single cell. The maximum power density of the single cells with the structure of NiO-BaZr0.1Ce0.7Y0.2O3−δ|BaZr0.1Ce0.7Y0.2O3−δ| BaFe0.5Sn0.2Bi0.3O3−δ (BFSBi0.3) reached 1277 mW cm−2 at 700 °C, which is a record-high performance for proton-conducting SOFCs using cobalt-free cathodes, compared with previous reports. The outstanding fuel cell performance and good long term stability indicate that bismuth-doping is an effective way of promoting proton-conduction in traditional cathodes. This study opens a new door to the design of high performance cathodes for proton-conducting SOFCs.

Tungsten is an important strategic metal, widely used in cemented carbide manufacturing, steel industry, and other economic fields. The amount of tungsten resource consumed in China each year accounts for more than 80% of the world’s annual total consumption. The purpose of this study is to quantify the environmental impact of tungsten production in China through the method of LCA. The result shows that, regarding the contributions of impact categories, the normalized value of HTP is the largest one among various impact categories, which accounts for 35.39% of the total environmental impact, followed by AP, PMFP, GWP, MDP, FDP, and POFP, respectively. The results also show that, regarding the contributions of production processes, smelting process is the largest contributor to the environmental burden of tungsten production due to the crystallization and calcination reduction occurred in the smelting process consumes a large amount of electricity, followed by mining, beneficiation, and transportation, respectively. The major academic contribution of this paper to the existing literatures is that we employed process-based analysis method, which could improve the accuracy of the study and provide practical advices for tungsten enterprises to reduce the environmental impact.

Two oxindole based π-conjugated polymers with same structures except the positions of selenium atoms in the main chains have been synthesized. The effects of heavy atom substitution on optical, electrochemical, and photovoltaic properties have been investigated. The polymer solar cell devices based on the new polymers as electron donors also have been studied. The oxindole based polymers showed intramolecular non-bonded interactions between divalent sulfur/selenium and carbonyl oxygen. The selenophene based polymers showed narrow optical band gaps. However, the introduction of selenophene led to the decline of optical absorption in both the monomer and the polymers compared with the thiophene based counterparts. The diminution of absorption in selenium containing polymers can have adverse effect on solar photon harvesting.

The demand for rare earths in aluminum alloy industry has experienced substantial growth in recent years. The erbium and scandium are two effective rare earth additives, mainly due to its remarkable improvement to aluminum alloy performance. However, the production process of rare earth has caused significant environmental problems. Hence, the analysis of environmental impacts associated with erbium and scandium processing is gaining importance. In this study, a life cycle analysis on the environment impacts of erbium oxide (Er2O3) and scandium oxide (Sc2O3) was carried out based on life cycle assessment (LCA) method. The life cycle assessment results showed that the production of 1 kg of Er2O3 and Sc2O3 generated 21.7 kg CO2 eq. and 743 kg CO2 eq., respectively. The leaching and purification process accounting for 95% of the overall water usage of Er2O3 production. For Sc2O3, energy and chemical consumption played a key role in reducing environmental impacts. Furthermore, Er2O3 appeared to have less environmental impact than Sc2O3 on most environmental issues. A detailed review of contribution was conducted and recommendations for further research were given.

Knowledge of how the molecular structures of ionic liquids (ILs) affect their properties at electrified interfaces is key to the rational design of ILs for electric applications. Polarizable molecular dynamics simulations were performed to investigate the structural, electrical, and dynamic properties of electric double layers (EDLs) formed by imidazolium dicyanamide ([ImX1][DCA]) at the interface with the molybdenum disulfide electrode. The effect of side chain of imidazolium on the properties of EDLs was analyzed by using 1-ethyl-3-methylimidazolium ([Im21]), 1-octyl-3-methylimidazolium ([Im81]), 1-benzyl-3-methylimidazolium ([ImB1]), and 1-(2-hydroxyethyl)-3-methylimidazolium ([ImO1]) as cations. Using [Im21] as reference, we find that the introduction of octyl or benzyl groups significantly alters the interfacial structures near the cathode because of the reorientation of cations. For [Im81], the positive charge on the cathode induces pronounced polar and non-polar domain separation. In contrast, the hydroxyl group has a minor effect on the interfacial structures. [ImB1] is shown to deliver slightly larger capacitance than other ILs even though it has larger molecular volume than [Im21]. This is attributed to the limiting factor for capacitance being the strong association between counter-ions, instead of the free space available to ions at the interface. For [Im81], the charging mechanism is mainly the exchange between anions and octyl tails, while for the other ILs, the mechanism is mainly the exchange of counter-ions. Analysis on the charging process shows that the charging speed does not correlate strongly with macroscopic bulk dynamics like viscosity. Instead, it is dominated by local displacement and reorientation of ions.

We demonstrate an efficient optical parametric oscillator at the telecom band using a triple-resonant, periodically poled lithium niobate microring resonator, which, to the best of our knowledge, delivers the lowest threshold power (∼30 µW) for on-chip OPOs so far.

Materials with strong second-order ( χ ( 2 ) ) optical nonlinearity, especially lithium niobate, play a critical role in building optical parametric oscillators (OPOs). However, chip-scale integration of low-loss χ ( 2 ) materials remains challenging and limits the threshold power of on-chip χ ( 2 ) OPO. Here we report an on-chip lithium niobate optical parametric oscillator at the telecom wavelengths using a quasi-phase-matched, high-quality microring resonator, whose threshold power ( ∼ 30 µ W ) is 400 times lower than that in previous χ ( 2 ) integrated photonics platforms. An on-chip power conversion efficiency of 11% is obtained from pump to signal and idler fields at a pump power of 93 µW. The OPO wavelength tuning is achieved by varying the pump frequency and chip temperature. With the lowest power threshold among all on-chip OPOs demonstrated so far, as well as advantages including high conversion efficiency, flexibility in quasi-phase-matching, and device scalability, the thin-film lithium niobate OPO opens new opportunities for chip-based tunable classical and quantum light sources and provides a potential platform for realizing photonic neural networks.

International audience; In order to implement radiotherapy based on a laser accelerator, it is necessary to precisely control the spatial distribution and energy spectrum of the proton beams to meet the requirements of the radiation dose distribution in the three-dimensional biological target. A compact laser plasma accelerator has been built at Peking University, which can reliably generate and transport MeV-energy protons with a specified energy onto the irradiation platform. In this paper, we discuss several technologies for the accurate control of a laser-accelerated proton beam with large divergence angle and broad energy spread, including the determination of the beam source position with micron accuracy, a tuning algorithm for the transport line which we refer to as “matching-image-point two-dimensional energy analysis” to realize accurate energy selection, and the control of beam distribution uniformity. In the prototype experiment with low energy protons and 0.5-Hz irradiation rate, a tailored energy deposition is demonstrated, which shows the potential feasibility of future irradiation based on laser-accelerated proton beams.

Microcavity solitons enable miniaturized coherent frequency comb sources. However, the formation of microcavity solitons can be disrupted by stimulated Raman scattering, particularly in the emerging crystalline microcomb materials with high Raman gain. Here, we propose and implement dissipation control---tailoring the energy dissipation of selected cavity modes---to purposely raise or lower the threshold of Raman lasing in a strongly Raman-active lithium niobate microring resonator and realize on-demand soliton mode locking or Raman lasing. Numerical simulations are carried out to confirm our analyses and agree well with experiment results. Our work demonstrates an effective approach to address strong stimulated Raman scattering for microcavity soliton generation.

The transferable, polarizable CL&Pol force field for aprotic ionic liquids presented in our previous study (J. Chem. Theory Comput. 2019, 15, 5858, DOI: 10.1021/acs.jctc.9b00689) is extended to electrolytes, protic ionic liquids, deep eutectic solvents, and glycols. These systems are problematic in polarizable simulations because they contain either small, highly charged ions or strong hydrogen bonds, which cause trajectory instabilities due to the pull exerted on the induced dipoles. We use a Tang-Toennies function to dampen, or smear, the interactions between charges and induced dipole at short range involving small, highly charged atoms (such as hydrogen or lithium), thus preventing the "polarization catastrophe". The new force field gives stable trajectories and is validated through comparison with experimental data on density, viscosity, and ion diffusion coefficients of liquid systems of the above-mentioned classes. The results also shed light on the hydrogen-bonding pattern in ethylammonium nitrate, a protic ionic liquid, for which the literature contains conflicting views. We describe the implementation of the Tang-Toennies damping function, of the temperature-grouped Nosé-Hoover thermostat for polarizable molecular dynamics and of the periodic perturbation method for viscosity evaluation from non-equilibrium trajectories in the LAMMPS molecular dynamics code. The main result of this work is the wider applicability of the CL&Pol polarizable force field to new, important classes of fluids, achieving robust trajectories and a good description of equilibrium and transport properties in challenging systems. The transferability and fragment-based approach of CL&Pol will allow ready extension to a wide variety of protic ionic liquids, deep eutectic solvents and electrolytes.

Leveraging on analyses of Hamiltonian dynamics to examine the ion motion, we explicitly demonstrate that the proton sheet crossing and plateau-type energy spectrum are two intrinsic features of the effectively accelerated proton beams driven by a drift quasistatic longitudinal electric field. Via two-dimensional particle-in-cell simulations, we show the emergence of proton sheet crossing in a relativistically transparent plasma foil irradiated by a linearly polarized short pulse with the power of one petawatt. Instead of successively blowing the whole foil forward, the incident laser pulse readily penetrates through the plasma bulk, where the proton sheet crossing takes place and the merged self-generated longitudinal electric field traps and reflects the protons to yield a group of protons with plateau-type energy spectrum.

Fluid transportation is a basic physical process in various engineering applications, and solid walls are most commonly used to confine fluid flows. Solid walls, however, have some disadvantages, including large pressure drops and plaguing by fouling. Here we experimentally demonstrate a method of controlling dielectric fluid flows on planar surfaces by virtual (not solid) walls through a spatially controlled charge deposition. Acting on the three-phase contact line, an electrically induced pressure has the same function as solid sidewalls. Dielectric fluids can be confined within designated areas, or flow directionally with the aid of contactless masks. Dielectric fluids can also move on planar surfaces by moving contactless masks. Due to the virtual wall effect of this novel method, an open channel can be developed to continuously transport fluids. The method may provide a new perspective to manipulating dielectric liquid flows and can be an alternative way of open fluidic devices.

High-resolution X-ray diffraction, temperature-dependent photoluminescence (PL), time-resolved PL, and positron annihilation spectroscopy are employed to investigate the degradation mechanism of InGaN/GaN multiple quantum wells (MQWs) light-emitting diodes (LEDs) under silicon ion irradiation. Reduction of the quantum-confined Stark effect due to crystalline strain relaxation, enhancement of indium localization due to thermal spike, generation of nonradiative recombination centers (NRCs), and carrier removal effect due to atom displacement are revealed to be critical factors in LEDs postirradiation performance. New NRCs are proven to be the main reason for the degradation of the internal quantum efficiency of MQWs. The increase of the threshold voltage and leakage current in LEDs are caused by the carrier removal effect and new defects in bandgap induced by radiation. In addition, new NRCs are found to appear earlier than indium localization and carrier removal effect with increasing silicon ion fluence. Atom displacement defects are revealed to be located mainly in p-type GaN and MQWs layers. Radiation-induced nitrogen vacancies are considered compensation donors in p-type GaN, whereas all other nitrogen and gallium-related defects are NRCs in MQWs.

Understanding the effect of percolation behavior of complex geometrical pores on the tortuosity and thermal conductivity of porous composites is very crucial to the design and optimization of porous composites. In this work, we adopt the continuum percolation theory to accurately determine the nonlinear thermal conductivity and tortuosity of porous composites composed of homogeneous solid matrix and three-dimensional pores of geometrical morphologies from the isotropic sphere to anisotropic polyhedra. Through extensive Monte Carlo simulations and the finite-size scaling analysis, the percolation threshold of spherical and polyhedral pores is obtained. Two continuum percolation-based models are respectively presented to derive the tortuosity and thermal conductivity of porous composites over the whole porosities range, including near the percolation threshold. Comparison with extensive experimental, numerical and theoretical results confirms that the present models are capable of accurately determining the percolation threshold and tortuosity of complex geometrical porous networks and the effective thermal conductivity of porous composites as conductor-superconductor and insulator-conductor media. Furthermore, we use the proposed models to probe the influences of pore shape and porosity on the tortuosity and thermal conductivity of porous composites. The results elucidate the intrinsic interplay of component, structure, and thermal conductivity of porous composites, which can provide sound guidance for porous composite design and evaluation.

In this paper, the electrochemical performance of nanostructured LaNi0.6Fe0.4O3-δ (LNF) infiltrated La2NiO4+δ (LNO) material was evaluated as a potential cathode for BaZr0.1Ce0.7Y0.2O3-δ (BZCY)-based proton-conducting solid oxide fuel cell (H-SOFC). The performance of LNO backbone cathodes with different loading amounts of LNF infiltrated phase were investigated, and electrochemical studies implied that the single cell with about 31 wt% LNF infiltrated cathode exhibited the lowest polarization resistance of 0.027 Ω cm2 and the highest maximum power density of 969 mWcm−2 at 700 °C, which were encouraging compared with that in previous reports of cobalt-free cathodes for H-SOFCs. This work demonstrated that the infiltrated LNF-LNO cathode had a great potential for H-SOFC and the optimization of the loading amount of LNF nanoparticles on LNO was critical for the fuel cell performance.

Knowledge of the thermodynamic properties of molecules is essential for chemical process design and the development of new materials. Experimental measurements are often expensive and not environmentally friendly. In the past, studies using molecular simulations have focused on a specific class of molecules, owing to the lack of a consistent force field and simulation protocol. To solve this problem, we have developed a high-throughput force field simulation (HT-FFS) procedure by combining a recently developed general force field with a validated simulation protocol to calculate thermodynamic properties for large number of molecules. This procedure is applied to calculate liquid densities, heats of vaporization, heat capacities, vapor-liquid equilibrium curves, critical temperatures, critical densities and surface tensions for a wide range of alkanes. The predictions agree well with available experimental data in terms of accuracy and precision, demonstrating that HT-FFS is a valid approach to supplementing experimental measurements. Furthermore, the large amount of data generated by HT-FFS lays a foundation for machine learning. We have developed an artificial neural network that demonstrates the feasibility of expanding predictions beyond simulation using a machine learning model.

The authors have synthesised a kind of low shrinkage alumina (Al2O3) aerogel using an inexpensive salt of aluminium (AlCl3·6H2O) via tetraethoxysilane modification and an ambient pressure drying process. The morphology, pore structure, surface group, crystal phase and thermal properties of the Al2O3 aerogel are analysed by X-ray diffractometer, scanning electron microscopy, Fourier transform infrared spectra and nitrogen adsorption test. Further improvement in thermal stability and thermal shrinkage are obtained by incorporation of silicon (Si) atoms during the aerogel preparation. The specific surface area of modified aerogel is 480 m2/g and the diameter shrinkage is 8% after drying, and reach 304 m2/g and 16.5% after heating at 1000°C. The approach, which is straightforward, inexpensive and safe, can be employed to prepare a monolithic mesoporous material with low shrinkage and high-temperature resistance. This will further promote the potential application of packaging and thermal insulation materials.

In this paper, a new method to regulate correlated color temperatures of white LEDs is proposed for the single-chip packaging structure. Its principle is based on modulating the blue light radiation distribution on patterned red/yellow phosphor layer through changing the paraffin layer transparence. The presented method has been demonstrated by experiments. The influences of the paraffin layer thickness and the phosphor layer concentration on the correlated color temperatures were tested and analyzed. When the thickness of paraffin layer is 1.2mm and the concentration of yellow and red phosphors is 30wt%, with the increase of voltage, the correlated color temperatures of white LEDs increases from 7886K to 9793K, then decreases to 3378K. Its modulating range of correlated color temperatures reaches 6415K. The paraffin layer has little bad effect on the luminous efficiency. The reduction of luminous efficiency of white LEDs is less than 10%.

Doped ceria (DCO) has high oxygen ionic conductivity, but the electronic conduction due to the reduction of Ce4+ to Ce3+ degrades its usage as an electrolyte material for solid oxide fuel cells. Inserting an electron-blocking layer is an attractive strategy to deal with this problem. In order to generate a Ba-containing electron blocking layer for DCO-based single cells, we applied BaMn1-xNixO3 (x = 0, 0.25, 0.5) mixed-oxide as an anode precursor material, and studied the solid reactions of it with NiO and SDC under the cell preparation conditions. XRD analysis indicates that the BaMn1-xNixO3 precursors are primarily BaMnO3/BaNiO3-δ mixed-oxides. It is found that BaMn1-xNixO3 reacts with SDC to form BaCeO3 and a novel Ba2(NiMnCe)2O6 double perovskite. SEM/EDS analyses reveal that BaCeO3 tends to accumulates at the anode-electrolyte interface, as well as to fill the closed pores in the SDC electrolyte. A 4 μm-thick electron-blocking layer with BaCeO3 as the main component effectively eliminates the internal-short-circuit and enhances the performance of the cell. The open circuit voltage and peak power density of the cell with such an electron-blocking layer are 1.010 eV and 621 mW cm−2 respectively at 650 °C.

Developing ceria-based solid oxide fuel cells (SOFCs) with low cost, high power density, and, in particular, high working efficiency is of great significance to practical applications. In this work, Ba- and Sr-containing composites (Ni–Ba1–xSrxCe0.7Zr0.1Y0.2O3−δ) were for the first time proposed and evaluated as anodes for Ce0.8Sm0.2O1.9 (SDC)-based SOFCs. Both Ba and Sr diffusion occurs at elevated temperatures during fabricating anode-supported half-cells; correspondingly, a thin electron-blocking interlayer is formed in situ at the anode/electrolyte interface. The presence of Ba ensures the formation of a BaCeO3-based electron-blocking layer, which has a very high ion transport number and completely eliminates the internal short circuit current across the SDC electrolyte. Sr incorporation can substantially promote the sintering activity of the anode and electrolyte and, hence, reduces the sintering temperature of the half-cells to 1150 °C. The electrochemical performance of the SDC-based cells varies s...