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Lithium titanium oxide (Li2TiO3) tritium breeder ceramic plates with nano- and coarse-grain size were fabricated. The preparation methods contained CTAB-modifying precursor, combining dry-pressing with isostatically cold-pressing, and calcinating at optimized sintering temperature in turn. Then their properties were characterized after radiation by 280 keV helium (He+) ion. Extensive characterization analyses were performed to reveal the changes in nano-grained and coarse-grained Li2TiO3 after radiation. They contained glancing angle X-ray diffraction (GIXRD), atomic force microscopy (AFM), electron spin resonance (ESR), and scanning electron microscopy (SEM). The results showed as follows, GIXRD peak position of the nano-grained Li2TiO3 was more stable than the coarse-grained Li2TiO3 after radiation. Nano-grained Li2TiO3 was less rough and swollen than the coarse-grained one after radiation. Nano-grained Li2TiO3 had more excellent structural stability and less defect concentration of Eʹ-center after radiation. As a result, nano-grained Li2TiO3 might have much better radiation tolerance than the coarse-grained one by comparing characterization results.

In perovskite solar cells, doped organic semiconductors are often used as charge-extraction interlayers situated between the photoactive layer and the electrodes. The π-conjugated small molecule 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9-spirobifluorene (spiro-OMeTAD) is the most frequently used semiconductor in the hole-conducting layer1-6, and its electrical properties considerably affect the charge collection efficiencies of the solar cell7. To enhance the electrical conductivity of spiro-OMeTAD, lithium bis(trifluoromethane)sulfonimide (LiTFSI) is typically used in a doping process, which is conventionally initiated by exposing spiro-OMeTAD:LiTFSI blend films to air and light for several hours. This process, in which oxygen acts as the p-type dopant8-11, is time-intensive and largely depends on ambient conditions, and thus hinders the commercialization of perovskite solar cells. Here we report a fast and reproducible doping method that involves bubbling a spiro-OMeTAD:LiTFSI solution with CO2 under ultraviolet light. CO2 obtains electrons from photoexcited spiro-OMeTAD, rapidly promoting its p-type doping and resulting in the precipitation of carbonates. The CO2-treated interlayer exhibits approximately 100 times higher conductivity than a pristine film while realizing stable, high-efficiency perovskite solar cells without any post-treatments. We also show that this method can be used to dope π-conjugated polymers.

Wastewater treatment is one of the focuses in current society, and the removal of heavy metal ions from it is crucial in wastewater treatment. Polyvinyl alcohol (PVA) nanofibers play a certain role in the adsorption of heavy metal ions, but their adsorption capacity is limited. In this work, maleic anhydride (MAH) was first grafted onto the molecular chain of PVA. Then through the condensation of the carboxyl group and the amino group, the octaamino-POSS was successfully grafted on the PVA molecular chain. Two kinds of nanofibers, PVA/octaamino-POSS nanofibers as well as PVA-g-POSS nanofibers, were fabricated by electrospinning technology for the adsorption of Pb2+ and Cu2+ in wastewater. The preparation of PVA/octaamino-POSS was used to compare which metal ion adsorption process was more stable, physical blending or chemical grafting. With the increase of contact time, the adsorption capacity of PVA/octaamino-POSS nanofibers to Cu2+ increased at first and then decreased. It was observed that the adsorption capacity of PVA-g-POSS to heavy metal ions was higher than that of PVA/octaamino-POSS. With the increase of octaamino-POSS content, the equilibrium adsorption of Pb2+ and Cu2+ on PVA-g-POSS nanofibers was significantly improved, with prominent adsorption effect for Cu2+. Based on the analysis of quasi-first-order and quasi-second-order dynamic equation, it was deduced that the chemical adsorption and physical adsorption worked together in the adsorption process of Pb2+ and Cu2+ by PVA-g-POSS, and chemical adsorption played a major role.

Long-term blood pressure (BP) monitoring is a widely used approach in a homecare intelligent system. However, BP is usually measured using cuff-based devices with tedious operation in practice, which may not be cost effective for continuous BP tracking. In this article, we propose a novel attention-based multitask network with a weighting scheme for BP estimation by analyzing and modeling single lead electrocardiogram (ECG) signals. Experimental results demonstrate that the proposed method could achieve mean error of systolic blood pressure, diastolic blood pressure, and mean arterial pressure estimation in levels of 0.18 $\pm$ 10.83, 1.24 $\pm$ 5.90, and 0.84 $\pm$ 6.47 mmHg, respectively. In comparison to other cutting-edge methods using ECG signals, the proposed method shows superior BP estimation performance. By integrating with a wearable/portable ECG monitoring device, the proposed model can be deployed to an embedded system or remote healthcare intelligent system to provide long-term BP monitoring service, which would help to reduce the incidence of malignant events happened in hypertensive population.

Li1.5Al0.5Ge1.5(PO4)3 (LAGP) is a solid-state electrolyte with high ionic conductivity and air stability but poor chemical stability and high interfacial impedance when directly contacted with Li metal. In this work, we develop an inorganic/polymer hybrid interlayer composed of Li bis(trifluoromethylsulfonyl)imide/poly(vinylene carbonate) polymer electrolyte and SiO2 submicrospheres to stabilize the Li/LAGP interface. The polymeric component renders high ionic conductance and low interfacial resistance, whereas the inorganic component imparts flame retardancy and a physical barrier to the known Li-LAGP side reaction, together enabling stable Li stripping/plating for more than 1,500 h at room temperature. With this interlayer at both electrodes, all-solid-state Li∥LiFePO4 full cells with stable cycling performance are also demonstrated.

Efficient plating/stripping of Na metal is critical to stable operation of any rechargeable Na metal battery. However, it is often overlooked or misunderstood in electrochemical measurements using thick Na electrodes with large excess of Na reserves. Herein, we report two crucial aspects, which have generally been ignored in previous studies, in the development of more practical capacity-controlled Na metal electrodes that can be efficiently cycled at 100% depth. We find that common carbonate electrolytes induce severe side reaction and highly irreversible Na plating/stripping, whereas ether electrolytes without any additive support thick Na metal electrodes operating at a high average Coulombic efficiency of 99.6% for over 300 cycles. We further show that to realize such high efficiency in thin Na metal electrodes, it is necessary to ensure strong adhesion between the thin Na layer and the Cu current collector, which we solve by introducing an Au interlayer. The resulting transferable thin Na metal electrodes enable high-energy-density, high-efficiency and reasonably stable-cycling Na∥Na3V2(PO4)3 batteries.

Electrochemical reduction of CO2 is a promising route for sustainable production of fuels. A grand challenge is developing low-cost and efficient electrocatalysts that can enable rapid conversion with high product selectivity. Here we design a series of nickel phthalocyanine molecules supported on carbon nanotubes as molecularly dispersed electrocatalysts (MDEs), achieving CO2 reduction performances that are superior to aggregated molecular catalysts in terms of stability, activity and selectivity. The optimized MDE with methoxy group functionalization solves the stability issue of the original nickel phthalocyanine catalyst and catalyses the conversion of CO2 to CO with >99.5% selectivity at high current densities of up to −300 mA cm−2 in a gas diffusion electrode device with stable operation at −150 mA cm−2 for 40 h. The well-defined active sites of MDEs also facilitate the in-depth mechanistic understandings from in situ/operando X-ray absorption spectroscopy and theoretical calculations on structural factors that affect electrocatalytic performance. Widespread deployment of electrochemical CO2 reduction requires low-cost catalysts that perform well at high current densities. Zhang et al. show that methoxy-functionalized nickel phthalocyanine molecules on carbon nanotubes can operate as high-performing molecularly dispersed electrocatalysts at current densities of up to −300 mA cm–2.

Bismuth layer-structured BaBi2Nb2O9 (BBN) and BaBi2Ta2O9 (BBT) relaxor ferroelectric ceramics were explored as potential energy storage materials. Remarkable energy storage performances were obtained in both BBN and BBT ceramics, featured by large recoverable energy storage density (~0.84 J/cm3 and ~0.68 J/cm3) and high energy storage efficiency (~90% and ~94%), respectively. Furthermore, both the two ceramics exhibit good thermal and frequency stabilities. Delightedly, both the BBN and BBT ceramics can complete the discharge process within 0.15 μs, resulting in ultrahigh current density of 195 A/cm2 and 234 A/cm2 and excellent power density of 10.74 MW/cm3 and 12.89 MW/cm3, respectively. The obtained results suggest that BaBi2Nb2O9 and BaBi2Ta2O9 ceramics could have a promising future in energy storage applications. This study also demonstrates that the bismuth layer-structured relaxor ferroelectric ceramic can be considered as a novel potential lead-free energy storage materials, in addition to the widely studied pervoskite-structured relaxor ferroelectric ceramics.

BiFeO3–BaTiO3 (BF-BT)-based lead-free ferroelectric ceramic has attracted immense interest in energy storage applications due to its great spontaneous polarization (Pmax) strength. However, high remanent polarization (Pr) has become a serious obstruction for its practical application. In this work, Sm ions were doped into 0.67BiFeO3-0.33BaTiO3 (0.67Bi1-xSmxFeO3-0.33BaTiO3, BSxF-BT) to tailor the structure and energy storage properties. It was found that the doping of Sm ions effectively reduced Pr by enhancing the relaxor behavior of BF-BT ceramic, which produce an enhancement in the energy storage performance. Large recoverable energy storage density Wrec of 2.8 J/cm3 with moderate energy storage efficiency η of 55.8% (200 kV/cm) were achieved in the ceramics with x = 0.1. Moreover, the energy storage capabilities exhibited good stability at temperature (20–95 °C) and frequency (0.1–50 Hz). Furthermore, the ceramic also possessed a predominant discharge speed with a discharge time less than 0.1 μs in a circuit with a load of 200 Ω. These results showed that the Wrec and η of BF-BT ceramic could be availably promoted by the doping of Sm ions, which may be helpful for the enhancement of energy storage performance of BF-BT-based ceramics.

A novel mass production method of lithium titanite (Li2TiO3) tritium breeder ceramic pebbles using polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) assisted granulation method (APG) was proposed. A binder solution of polyvinyl alcohol (PVA) was used to modify the Li2TiO3 precursor powder. The powders with adhesive properties were prilled to form green pebbles (GPs) by spheronization at a low rotation speed and spraying with polyvinyl pyrrolidone (PVP), in several cycles. Then, the density and the crush load of the GPs were improved by high-speed rolling. Finally, the ceramic pebbles were produced by sintering. The phase, the microstructure, and the crush load of the ceramic pebbles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and with a universal tester, respectively.

Synthesis of fine Li2TiO3 powders via low-temperature solid-state reaction (LTSSR) was studied. Solid Li2CO3 and H2TiO3 were blended by planetary ball mill with deionized water as medium. Calcination of the milled powder at low temperature of 500 °C resulted in the formation of pure Li2TiO3 nanoparticles. Another Li2TiO3 powder was also prepared by the conventional solid-state reaction (SSR) and a good comparison between different routes was realized. The results show that the particle size of LTSSR powder is significantly decreased to 19.6 nm while the one obtained by SSR is 146.6 nm. Low temperature calcined powders have less agglomeration and higher sinterability, which can be sintered at lower temperature. Pebbles sintered from the LTSSR powders at 750 °C exhibit small grain size (650 nm), high relative density (85.1%) and satisfactory crush load (42.8 N), whereas the SSR pebbles can only be sintered above 950 °C with the relative density close to 80%. Besides, the LTSSR samples also have a higher conductivity at room temperature, indicating the lower tritium diffusion barrier in ceramics. It is confirmed that H2TiO3 rather than TiO2 is more appropriate for the solid-state reaction to produce Li2TiO3 powders with nano-size particles and favorable properties.

Polysaccharide has been considered as an important bioactive compound in Codonopsis lanceolata. High fat/high sucrose (HFHS) diet-induced insulin resistance is implicated in multiple metabolic diseases, such as type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD), these metabolic diseases has become epidemic health issue worldwide. In this study, the effect of C. lanceolata polysaccharide (CLPS) on improving insulin sensitivity in chronic HFHS diet-fed mice was investigated. Our data indicates that CLPS significantly reduced fasting blood glucose (FBG), fasting serum insulin (FINS) and insulin resistance index, in parallel with improved glucose and insulin tolerance impaired by HFHS diet. Impaired phosphorylation of PKB/Akt and hyperphosphorylation of IRS-1 at Ser307 were observed in the mice fed with HFHS diet, and those defects were also rescued by CLPS administration. In addition, CLPS caused a significant decrease in the level of malondialdehyde (MDA), and an increase in reduced glutathione (GSH)/oxidised glutathione (GSSG) ratio; concurrent with enhanced expression of antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT), and activated Nrf2 signaling. In summary, these findings suggest that CLPS ameliorates HFHS diet-induced insulin resistance through activating anti-oxidative signaling pathway, providing new insights into the protective effects of C. lanceolata polysaccharide in metabolic disease.

The quality of emergency training determines the professional ability of emergency personnel. To evaluate the safety of emergency training for building collapse ruin training scenarios, an approach combining analytic hierarchy process (AHP) and gray-fuzzy evaluation is proposed. According to the characteristics of building collapse ruin training scenarios and the principle of index selection, a safety evaluation index system for this training is constructed from four aspects: human, machine, environment, and management. AHP is used to determine the weight of each evaluation index, and the evaluation model is established base of the gray-fuzzy evaluation method. Based on the combination of the two methods, the quantitative results on training safety was obtained and the most important factor that have the greatest impact on training safety was found. Using this presented assessment method, the safety of an building collapse ruin training scenario for a domestic emergency training facility are assessed, the defects in its emergency capacity are determined, and measures and suggestions are recommended to provide scientific and effective basis for improving emergency capacity.

Electrochemical carbon dioxide (CO2) reduction can in principle convert carbon emissions to fuels and value-added chemicals, such as hydrocarbons and alcohols, using renewable energy, but the efficiency of the process is limited by its sluggish kinetics1,2. Molecular catalysts have well defined active sites and accurately tailorable structures that allow mechanism-based performance optimization, and transition-metal complexes have been extensively explored in this regard. However, these catalysts generally lack the ability to promote CO2 reduction beyond the two-electron process to generate more valuable products1,3. Here we show that when immobilized on carbon nanotubes, cobalt phthalocyanine—used previously to reduce CO2 to primarily CO—catalyses the six-electron reduction of CO2 to methanol with appreciable activity and selectivity. We find that the conversion, which proceeds via a distinct domino process with CO as an intermediate, generates methanol with a Faradaic efficiency higher than 40 per cent and a partial current density greater than 10 milliamperes per square centimetre at −0.94 volts with respect to the reversible hydrogen electrode in a near-neutral electrolyte. The catalytic activity decreases over time owing to the detrimental reduction of the phthalocyanine ligand, which can be suppressed by appending electron-donating amino substituents to the phthalocyanine ring. The improved molecule-based electrocatalyst converts CO2 to methanol with considerable activity and selectivity and with stable performance over at least 12 hours. Individual cobalt phthalocyanine derivative molecules immobilized on carbon nanotubes effectively catalyse the electroreduction of CO2 to methanol via a domino process with high activity and selectivity and stable performance.

The past decade has seen the proliferation of health information portals; however, consumer acceptance of the portals has proven difficult and rate of use has been limited. This study developed a consumer acceptance model by integrating usability and social cognitive theories with the technology acceptance model to explain young Internet users’ acceptance of health information portals. Participants (n = 201) completed a self-report questionnaire measuring model constructs after attending a usability testing with a typical health information portal. Results showed that the hypothesized model accounted for 56 percent of the variance in behavioral intention to use the portal and explained consumer acceptance well. Both subjective usability and application-specific self-efficacy served as significant antecedents in the model, while application-specific self-efficacy also moderated the effect of subjective usability on perceived ease of use. The findings can help practitioners with the design and implementation of health information portals and other health informatics applications in support of consumer acceptance.

A comparative study between the microwave and conventional sintering of Li2TiO3–Li4SiO4 biphasic ceramic pebbles was systematically performed. Comparing to samples sintered by conventional method, the microwave sintered samples exhibited homogeneous microstructure with uniform grain size distribution. In addition, the microwave sintered samples showed higher relative density (86.0% T.D.) and crush load (22.7 N). The results indicated that the microwave sintering process is a prospective method for fabricating Li2TiO3–Li4SiO4 biphasic ceramic pebbles with excellent mechanical performance as tritium breeder materials.

Lithium metatitanate (Li2TiO3) ceramic pebbles were fabricated from the powder synthesised via low-temperature solid-state precursor method. Solid H2TiO3 and LiOH·H2O react chemically during ball milling process to form a nano-sized precursor powder. Pure β-Li2TiO3 powder can be obtained by calcining the precursor powder at 500 °C, which is half the temperature of conventional solid-state method. The synthesis process is simple and low-cost, which would be more available to achieve batch production among all feasible techniques. The low-temperature calcination will effectively avoid hard particle aggregates and poor sinterability caused by high-temperature heat treatment, which is conducive to prepare ceramics with good properties. The results show that the powder exhibits high sinterability with small particle size of 19 nm. The Li2TiO3 ceramic pebbles sintered at 800 °C have small grain size (470 nm), high relative density (83%) and good crush load (45 N), which has great potential as tritium breeding materials for fusion reactors.

Carbon-based CsPbI3 perovskite solar cells (CsPbI3 C-PSCs) without hole-transporting materials have been attracting much attention because of their high stability. However, the electron transport l...

Water splitting is an efficient strategy to produce purity hydrogen and convert intermittent electricity from renewable wind and solar sources. In this work, dense NiMoO4 micro-pillars arrays (MPAs) were in-situ grown on nickel foam (NF) through facile hydrothermal method, then the NiMoO4/NF were converted into NiMoO4–P/NF and NiFe/NiMoO4/NF via phosphating and electrodeposition method, respectively. The NiMoO4–P/NF electrode required small overpotentials of 34 mV@10 mA cm−2 and 130 mV@100 mA cm−2 for hydrogen evolution reaction (HER). The NiFe/NiMoO4/NF electrode exhibited excellent oxygen evolution reaction (OER) activity with overpotentials of 210 mV@10 mA cm−2 and 300 mV@100 mA cm−2. The overall water splitting using the anode-cathode couple of NiFe/NiMoO4/NF||NiMoO4–P/NF only consumes low voltages of 1.47 V@10 mA cm−2 for 100 h and 1.66 V@100 mA cm−2 for 50 h in 1 M KOH. The electronic modification and the well-designed hierarchical structure contribute the high energy-efficient and stabile overall water splitting.

The fast multi-pole indirect boundary element method (FM-IBEM) is proposed to efficiently solve the high-frequency and large-scale two-dimensional (2-D) elastic wave scattering in a fluid-saturated poroelastic heterogeneous medium. The diffracted wave fields are constructed by applying virtual distributed loads and fluid sources on the boundaries according to the single-layer potential theory, and the multi-pole moment and local expansion coefficients of 2-D Green's function are deduced based on Graf addition theorem. Numerical results illustrated that the proposed method can essentially reduce the calculation CPU time and the memory requirement. The 2-D scattering of elastic waves by a canyon and a group of cracks in a fluid-saturated poroelastic half-space is further investigated. It shows that the scattering characteristics are closely related to the incident frequency, porosity of the medium and special topography. There is a significant ground motion amplification effect around the canyon, while a group of cracks produce an isolation effect on the half-space surface motion.

An advanced core-shell ceramic pebble with Li4TiO4 pure phase core and Li2TiO3 nanostructured shell was prepared by a physical coating method. The phase compositions, morphology and microstructure of Li4TiO4–Li2TiO3 core-shell ceramic pebbles were investigated. We discovered that using chitosan solution to assist rolling coating helps to improve the coating uniformity of core-shell green pebbles. In addition, the results show that the obtained Li4TiO4–Li2TiO3 core-shell ceramic pebbles have a diameter of ∼1.1 mm, the shell thickness of ∼13 μm and density of 2.31 ± 0.03 g/cm3. It is also noted that the Li2TiO3 shell still maintains the nanostructure (∼80 nm) after sintering. This study provides a feasible method for preparing Li4TiO4–Li2TiO3 core-shell ceramic pebbles which have a great potential application for the test blanket module (TBM) of International Thermonuclear Experimental Reactor (ITER).

In this study, Li 2 O porous ceramic pebbles were synthesized by decomposing the xLi 2 CO 3 -yLiNO 3 precursor pebbles at low temperature. This efficient decomposition reaction was mainly attributed to the two-stage support decomposition of Li 2 CO 3 and LiNO 3 . The results indicated that the molar ratio of Li 2 CO 3 and LiNO 3 will directly affect the phase composition, pore structure and crush load of sintered pebbles. The high-purity Li 2 O ceramic pebbles sintered from Li 2 CO 3 –LiNO 3 precursor pebbles at 730 °C exhibits the open porosity of 24.8 ± 0.7%. The crush load of the ceramic reaches 21.18 ± 1.38 N although the structure was porous. The Li 2 O porous ceramics fabricated in this study will have potential application in tritium breeder materials.

Effects of cetyl trimethyl ammonium bromide (CTAB) on the formation of Li2TiO3 nanocrystals during ethanol-water solvothermal reactions were investigated. Addition of CTAB changed Li2TiO3 crystalline morphology from large to small aggregate particles due to the steric repulsion and electrostatic interaction of the CTAB ligands. Aggregate particle size of the Li2TiO3 precursor was reduced from 455.2 to 138.7 nm by preventing their agglomeration after CTAB addition. This was followed by sintering the green body prepared with the CTAB-modified precursor powders using an indirect wet method, then the nanostructured Li2TiO3 ceramic pebbles were obtained at relatively low temperatures from 750 to 800 °C for 4 h. Nanostructured Li2TiO3 ceramic pebbles had small grains and a large number of grain boundaries, which might potentially improve the radiation tolerance, tritium release rate, and mechanical properties of Li2TiO3 tritium breeder pebbles. In addition, grain growth mechanisms as function of different sintering temperatures, crush load as well as relative density of fabricated nanostructured Li2TiO3 ceramic pebbles were also investigated.

In order to improve the shear behavior of hollow concrete block masonry, precast concrete anti-shear blocks were proposed to enhance the shear strength of hollow concrete block masonry. Four groups of hollow concrete block masonry triplets with precast concrete anti-shear blocks were tested under shear loading, and their behaviors were compared with a control group. The results show that as the height of precast concrete anti-shear blocks increases, the shear strength of the masonry increases. The maximum shear strength of masonry triplets with precast concrete anti-shear blocks was 234.48 percent higher than that of the control specimens. The shear strength of masonry triplets was mainly determined by the failure of hollow concrete block unit. The majority of specimens exhibited double shear failures; however, these failures showed characteristics of ductile failure to a certain extent. Based on the experimental results, a equation for calculating the shear strength of masonry with precast concrete anti-shear blocks was proposed.

In this paper, a method combining hydrolysis of tetrabutyl orthotitanate (TBOT) and solvothermal reaction was first used to fabricate nanostructured Li2TiO3 tritium breeder ceramic pebbles. Initially, superfine nanostructured Li2TiO3 powders were synthesized with average particle size of about 10 nm, according to TEM. The surface area of precursor particles synthesized via this method was found to be 115.85 m2/g by BET analysis, which is much larger than that of the product obtained using traditional methods. The results showed that precursor particles had high sintering activity. XRD pattern revealed that the phase transition temperature for monoclinic phase Li2TiO3 prepared by this method was nearly 450 °C, which was the lowest phase transition temperature reported among all wet chemical methods to date. Subsequently, investigation of ceramic sintering demonstrated that Li2TiO3 ceramic pebbles with desired nano-crystalline sizes (27.98 ~ 55.03 nm) were obtained by sintering at 500 ~ 600 °C for 4 h. The possible mechanisms were proposed based on the reaction processes of TBOT hydrolysis, solvothermal reaction and sintering.

Rechargeable zinc air batteries (ZABs) have gained considerable attention as a promising energy technique recently owing to their high theoretical energy and power density, safety and economic viability; however, the state-of-art ZABs have been plagued by two major drawbacks, unsatisfying achievable power density and low voltage efficiency. Our superwetting electrodes are hereby designed to circumvent these issues through controlling the O2 bubbles adsorption/evolution behavior at electrode surface while maintaining the outstanding electrocatalysis performance. In this work, we demonstrate for the first time the application of superwetting catalytic electrodes in the tri-electrode rechargeable ZABs. Two different functional electrodes, namely superaerophilic cobalt-incorporated nitrogen-doped carbon nanotubes hybrid catalyst and superaerophobic NiFe-layered double hydroxide arrays, serve as exceptional catalysts for discharging and charging process respectively, thus achieving superior battery performance. The low-cost superwetting cathode pairs even exhibit a much better catalytic activity and durability than the combination of precious Pt/C and Ir/C catalysts. The as-assembled ZABs deliver a greatly improved peak power current of 245 mW cm−2 at 396 mA cm−2 over that of the ZABs composed of precious metal electrodes (186 mW cm−2), together with small polarization, high reversibility, and stability over long cycles. The design of superwetting electrode marks a general and effective strategy to achieve high-performance rechargeable ZABs.

The tritium release behavior of the Li4SiO4 pebbles and Li4SiO4 + 5 mol% TiO2 pebbles with small grain sizes was investigated. The tritium release results of Li4SiO4 pebbles with different grain sizes (0.3 μm and 1.5 μm) indicated that the grain size had little effect on the tritium release regardless of the difference in gas composition of purge gas. Moreover, the tritium release of small grained pebbles was dominated by the desorption process, since the addition of H2 to purge gas substantially affected the release behavior. The modified Li4SiO4 pebbles with addition of TiO2 exhibited enhanced water formation capacity due to the increased concentration of active point as the oxygen supplier. Obvious tritiated water release peaks around 690 °C could be observed from the Li4SiO4 + 5 mol% TiO2 pebbles under 0.1%H2+He purge gas. The modified Li4SiO4 pebbles also showed improved tritium release behavior, the tritium release peaks shifted to lower temperatures compared to Li4SiO4 pebbles.

Estimating blood pressure via combination analysis with electrocardiogram and photoplethysmography signals has attracted growing interest in continuous monitoring patients’ health conditions. However, most wearable/portal monitoring devices generally acquire only one kind of physiological signals due to the consideration of energy cost, device weight and size, etc. In this study, a novel adaptive weight learning-based multitask deep learning framework based on single lead electrocardiogram signals is proposed for continuous blood pressure estimation. Specifically, the proposed method utilizes a 2-layer bidirectional long short-term memory network as the sharing layer, followed by three identical architectures of 2-layer fully connected networks for task-specific blood pressure estimation. To learn the importance of task-specific losses automatically, an adaptive weight learning scheme based on the trend of validation loss is proposed. Extensive experiment results on Physionet Multiparameter Intelligent Monitoring in Intensive Care (MIMIC) II waveform database demonstrate that the proposed method using electrocardiogram signals obtains estimating performance of 0.12±10.83 mmHg, 0.13±5.90 mmHg, and 0.08±6.47 mmHg for systolic blood pressure, diastolic blood pressure, and mean arterial pressure, respectively. It can meet the requirements of the British Hypertension Society standard and US Association of Advancement of Medical Instrumentation standard with a considerable margin. Combined with a wearable/portal electrocardiogram device, the proposed model can be deployed to a healthcare system to provide a long-term continuous blood pressure monitoring service, which would help to reduce the incidence of malignant complications to hypertension.

Many transition metal sulfides and phosphides are susceptible to surface oxidation under ambient conditions. The formed surface oxidation layer, which is likely to further restructure under reaction conditions, alters the chemical properties of the pristine material but has not been well studied. In this work, we for the first time use X-ray photoelectron spectroscopy to quantify the natural surface oxidation of transition metal phosphide and sulfide nanoparticles and employ a simplified Deal-Grove model to analyze the kinetics. We show that CoS2 oxidizes faster than CoS whereas CoP2 is more difficult to oxidize compared to CoP, and there exists an inverse correlation between the surface oxidation rate and the Co-S/P distance in the pristine structure. More inclusive investigation unveils different types of surface oxidation behavior: CoS, NiS and FeS are limited by their reactivity with oxygen; CoS2 is the most reactive and its oxidation is governed by oxygen diffusion; CoP2 is influenced by both reactivity and diffusion; CoP, Ni2P, Cu3P and MoP exhibit high initial oxidation degrees and the kinetics are not well-defined; MoS2 is largely stable against oxidation.

Molecular catalysts for electrochemical CO2 reduction have traditionally been studied in their dissolved states. However, the heterogenization of molecular catalysts has the potential to deliver much higher reaction rates and enable the reduction of CO2 by more than two electrons. In light of the recently discovered reactivity of heterogenized cobalt phthalocyanine molecules to catalyze CO2 reduction into methanol, direct comparison is needed to uncover the distinct catalytic activity and selectivity in homogeneous catalysis versus heterogeneous catalysis. Herein, soluble cobalt phthalocyanine derivatives were synthesized, and their catalytic activities in the homogeneous solutions were evaluated. The results show that the observed catalytic activities for both CO2 -to-CO and CO-to-methanol conversions in aqueous solutions of the cobalt phthalocyanines are predominantly heterogeneous in nature through the adsorbed species on the electrode.

Hetero-element doped lithium orthosilicates have been considered as advanced tritium breeders due to the superior performances. In this work, Li4Si1−xTixO4 ceramics were prepared by proprietary hydrothermal process and multistage reactive sintering. The reaction mechanism of Li4Si1−xTixO4 was put forward. XRD and SEM analyses indicate that insertion of Ti leads to lattice expansion, which promotes the grain growth and changes the fracture mode. The compressive tests show that the crush load increases almost four times by increasing x from 0 to 0.2. However, the thermal conductivity and ionic conductivity are the best when x = 0.05 and x = 0.1, respectively. Thermal cycling stability of Li4Si1−xTixO4 pebbles was further appraised through investigating the changes of microstructure and crush load. After undergoing thermal cycling, the Li4Si1−xTixO4 still show higher crush load compared with Li4SiO4, despite Ti segregation in some samples. The x = 0.05 sample exhibits excellent thermal cycling stability. In summary, proper amount of Ti doping can improve the crush load, thermal and ionic conductivity, and thermal cycling stability of Li4SiO4.

Background Poor balance has been cited as one of the key causal factors of falls. Timely detection of balance impairment can help identify the elderly prone to falls and also trigger early interventions to prevent them. The goal of this study was to develop a surrogate approach for assessing elderly’s functional balance based on Short Form Berg Balance Scale (SFBBS) score. Methods Data were collected from a waist-mounted tri-axial accelerometer while participants performed a timed up and go test. Clinically relevant variables were extracted from the segmented accelerometer signals for fitting SFBBS predictive models. Regularized regression together with random-shuffle-split cross-validation was used to facilitate the development of the predictive models for automatic balance estimation. Results Eighty-five community-dwelling older adults (72.12 ± 6.99 year) participated in our study. Our results demonstrated that combined clinical and sensor-based variables, together with regularized regression and cross-validation, achieved moderate-high predictive accuracy of SFBBS scores (mean MAE = 2.01 and mean RMSE = 2.55). Step length, gender, gait speed and linear acceleration variables describe the motor coordination were identified as significantly contributed variables of balance estimation. The predictive model also showed moderate-high discriminations in classifying the risk levels in the performance of three balance assessment motions in terms of AUC values of 0.72, 0.79 and 0.76 respectively. Conclusions The study presented a feasible option for quantitatively accurate, objectively measured, and unobtrusively collected functional balance assessment at the point-of-care or home environment. It also provided clinicians and elderly with stable and sensitive biomarkers for long-term monitoring of functional balance.

Background Telehealth is an effective means to assist existing health care systems, particularly for the current aging society. However, most extant telehealth systems employ individual data sources by offline data processing, which may not recognize health deterioration in a timely way. Objective Our study objective was two-fold: to design and implement an integrated, personalized telehealth system on a community-based level; and to evaluate the system from the perspective of user acceptance. Methods The system was designed to capture and record older adults’ health-related information (eg, daily activities, continuous vital signs, and gait behaviors) through multiple measuring tools. State-of-the-art data mining techniques can be integrated to detect statistically significant changes in daily records, based on which a decision support system could emit warnings to older adults, their family members, and their caregivers for appropriate interventions to prevent further health deterioration. A total of 45 older adults recruited from 3 elderly care centers in Hong Kong were instructed to use the system for 3 months. Exploratory data analysis was conducted to summarize the collected datasets. For system evaluation, we used a customized acceptance questionnaire to examine users’ attitudes, self-efficacy, perceived usefulness, perceived ease of use, and behavioral intention on the system. Results A total of 179 follow-up sessions were conducted in the 3 elderly care centers. The results of exploratory data analysis showed some significant differences in the participants’ daily records and vital signs (eg, steps, body temperature, and systolic blood pressure) among the 3 centers. The participants perceived that using the system is a good idea (ie, attitude: mean 5.67, SD 1.06), comfortable (ie, self-efficacy: mean 4.92, SD 1.11), useful to improve their health (ie, perceived usefulness: mean 4.99, SD 0.91), and easy to use (ie, perceived ease of use: mean 4.99, SD 1.00). In general, the participants showed a positive intention to use the first version of our personalized telehealth system in their future health management (ie, behavioral intention: mean 4.45, SD 1.78). Conclusions The proposed health monitoring system provides an example design for monitoring older adults’ health status based on multiple data sources, which can help develop reliable and accurate predictive analytics. The results can serve as a guideline for researchers and stakeholders (eg, policymakers, elderly care centers, and health care providers) who provide care for older adults through such a telehealth system.

Surface functionalization with organic electron donors (OEDs) is an effective doping strategy for two-dimensional (2D) materials, which can achieve doping levels beyond those possible with conventional electric field gating. While the effectiveness of surface functionalization has been demonstrated in many 2D systems, the doping efficiencies of OEDs have largely been unmeasured, which is in stark contrast to their precision syntheses and tailored redox potentials. Here, using monolayer MoS2 as a model system and an organic reductant based on 4,4-bipyridine (DMAP-OED) as a strong organic dopant, we establish that the doping efficiency of DMAP-OED to MoS2 is in the range of 0.63 to 1.26 electrons per molecule. We also achieve the highest doping level to date in monolayer MoS2 by surface functionalization and demonstrate that DMAP-OED is a stronger dopant than benzyl viologen, which was the previous best OED dopant. The measured range of the doping efficiency is in good agreement with the values predicted from first-principles calculations. Our work provides a basis for the rational design of OEDs for high-level doping of 2D materials., Comment: 19 pages, 4 figures, 1 table

Microwave sintering was employed in the fabrication of Li2TiO3 ceramic pebbles using the powders synthesized via hydrothermal method. The as-prepared Li2TiO3 powders exhibited high reactivity with an average particle size as small as 40 nm. A comparative study between the microwave and conventional sintering behavior of Li2TiO3 pebbles was systematically investigated. The microstructure and density analyses showed that the presence of microwaves accelerated the densification and grain growth, thus decreasing the sintering temperature. Besides, an accelerated phase transformation from α-Li2TiO3 to β-Li2TiO3 was observed in microwave processing. The Li2TiO3 ceramic pebbles obtained by microwave sintering exhibited high density, good mechanical property and uniform microstructure, which might hold good potential as tritium breeding materials for blankets. The results showed that the microwave sintering was a promising process for the fabrication of Li2TiO3 pebbles.

Understanding how remarkable properties of materials emerge from complex interactions of their constituents and designing advanced material structures to render desired properties are grand challenges. Metal–oxide interactions are frequently utilized to improve catalytic properties but are often limited to situations where only one component is facilitated by the other. In this work, we demonstrate highly cooperative win-win metal–oxide interactions that enable unprecedented catalytic functionalities for electrochemical CO2 reduction reactions. In a single SnOx/Ag catalyst, the oxide promotes the metal in the CO production mode, and meanwhile the metal promotes the oxide in the HCOOH production mode, achieving potential-dependent bifunctional CO2 conversion to fuels and chemicals with H2 evolution suppressed in the entire potential window. Spectroscopic studies and computational simulations reveal that electron transfer from Ag to SnOx and dual-site cooperative binding for reaction intermediates at the Sn...

Lithium metatitanate (Li2TiO3) ceramic pebbles were successfully fabricated by microwave sintering using the powders synthesized via solid state reaction. Nano-size Li2TiO3 powders with an average particle size of 45 nm were synthesized by solid state reaction, and wet process was employed to fabricate Li2TiO3 pebbles with good sphericity. The pebbles were sintered by microwave process with rapid heating rate. Due to the volumetric heating and enhanced diffusion of microwave sintering, the sintered Li2TiO3 ceramic pebbles show high density (>85%T.D.), high crush load and uniform microstructure with small grain size (100 nm–1 μm), which might hold good potential in tritium release and long-term stability. The results show that the microwave sintering is a promising process for the fabrication of Li2TiO3 pebbles with fine microstructure and good mechanical property.

The promise and challenge of electrochemical mitigation of CO2 calls for innovations on both catalyst and reactor levels. In this work, enabled by our high-performance and earth-abundant CO2 electroreduction catalyst materials, we developed alkaline microflow electrolytic cells for energy-efficient, selective, fast, and durable CO2 conversion to CO and HCOO–. With a cobalt phthalocyanine-based cathode catalyst, the CO-selective cell starts to operate at a 0.26 V overpotential and reaches a Faradaic efficiency of 94% and a partial current density of 31 mA/cm2 at a 0.56 V overpotential. With a SnO2-based cathode catalyst, the HCOO–-selective cell starts to operate at a 0.76 V overpotential and reaches a Faradaic efficiency of 82% and a partial current density of 113 mA/cm2 at a 1.36 V overpotential. In contrast to previous studies, we found that the overpotential reduction from using the alkaline electrolyte is mostly contributed by a pH gradient near the cathode surface.

Li4TiO4 ceramics pebbles have been proposed to be a promising tritium breeder materials for the fusion reactor blanket of the International Thermonuclear Experimental Reactor (ITER). In the present study, the hydrothermal method was first used to synthesize the nanostructured precursor powders for fabricating the Li4TiO4 ceramic pebbles. The precursor powders were composed of LiOH, Li2CO3 and Li2TiO3 with a grain size of 30–80 nm. Moreover, the microstructure and phase evolution of Li4TiO4 ceramics pebbles were investigated. The results indicated that the formation temperature of Li4TiO4 by hydrothermal method was lower than that of other methods. The pure phase Li4TiO4 ceramic pebbles with small grain size (average value 0.50 μm), satisfactory crush load (average value 41 N) and reasonable pore structure was sintered at 750 °C for 4 h in vacuum. This study provides a new method for preparing a high quality Li4TiO4 ceramic pebble, which has potential application as a tritium breeding material.

Tritium trapping at point defects is a major issue concerning tritium extraction efficiency in solid state breeder materials in future fusion reactors. Here, tritium trapping behaviors at oxygen vacancies in Li4SiO4 have been investigated by density functional theory simulations. Formation energies have been calculated to determine the stability of defects in various charge states. Density of states, charge distribution and atomic charge has been calculated to investigate the mechanism of defect formation. The results showed that the neutral and 2 + charged oxygen vacancies are the most stable species and are both diamagnetic. The 1 + charged paramagnetic oxygen vacancy (E′ center) is less stable. In addition, the tritium-trapped O-vacancy is most stable when the defect complex is 1 + charged. The trapped tritium is bonded to Si forming a T-SiO3 unit. Other charge states of the complex may lead to unstable defect structures and high formation energies, forcing tritium to escape the vacancy.

Background The accelerated growth of elderly population is creating a heavy burden to the healthcare system in many developed countries and regions. Electrocardiogram (ECG) analysis has been recognized as effective approach to cardiovascular disease diagnosis and widely utilized for monitoring personalized health conditions. Method In this study, we present a novel approach to forecasting one-day-forward wellness conditions for community-dwelling elderly by analyzing single lead short ECG signals acquired from a station-based monitoring device. More specifically, exponentially weighted moving-average (EWMA) method is employed to eliminate the high-frequency noise from original signals at first. Then, Fisher-Yates normalization approach is used to adjust the self-evaluated wellness score distribution since the scores among different individuals are skewed. Finally, both deep learning-based and traditional machine learning-based methods are utilized for building wellness forecasting models. Results The experiment results show that the deep learning-based methods achieve the best fitted forecasting performance, where the forecasting accuracy and F value are 93.21% and 91.98% respectively. The deep learning-based methods, with the merit of non-hand-crafted engineering, have superior wellness forecasting performance towards the competitive traditional machine learning-based methods. Conclusion The developed approach in this paper is effective in wellness forecasting for community-dwelling elderly, which can provide insights in terms of implementing a cost-effective approach to informing healthcare provider about health conditions of elderly in advance and taking timely interventions to reduce the risk of malignant events.

Structure and electrocatalytic reactivity of cobalt mono-phosphosulfide nanoparticles supported on carbon nanotubes are investigated. Employing two different synthetic methods, we successfully synthesize cobalt mono-phosphosulfide nanoparticles adopting either the CoP crystal structure (CoP|S with the S/P ratio

Discovering new chemistry and materials to enable rechargeable batteries with higher capacity and energy density is of paramount importance. While Li metal is the ultimate choice of a battery anode, its low efficiency is still yet to be overcome. Many strategies have been developed to improve the reversibility and cycle life of Li metal electrodes. However, almost all of the results are limited to shallow cycling conditions (e.g., 1 mAh cm −2 ) and thus inefficient utilization ( −2 with average Coulombic efficiency >98% in a commercial LiPF 6 /carbonate electrolyte. The high performance is enabled by slow release of LiNO 3 into the electrolyte and its subsequent decomposition to form a Li 3 N and lithium oxynitrides (LiN x O y )-containing protective layer which renders reversible, dendrite-free, and highly dense Li metal deposition. Using the developed Li metal electrodes, we construct a Li-MoS 3 full cell with the anode and cathode materials in a close-to-stoichiometric amount ratio. In terms of both capacity and energy, normalized to either the electrode area or the total mass of the electrode materials, our cell significantly outperforms other laboratory-scale battery cells as well as the state-of-the-art Li ion batteries on the market.

Developing Na metal anodes that can be deeply cycled with high efficiency for a long time is a prerequisite for rechargeable Na metal batteries to be practically useful despite their notable advantages in theoretical energy density and potential low cost. Their high chemical reactivity with the electrolyte and tendency for dendrite formation are two major issues limiting the reversibility of Na metal electrodes. In this work, we introduce for the first time potassium bis(trifluoromethylsulfonyl)imide (KTFSI) as a bifunctional electrolyte additive to stabilize Na metal electrodes, in which the TFSI- anions decompose into lithium nitride and oxynitrides to render a desirable solid electrolyte interphase layer while the K+ cations preferentially adsorb onto Na protrusions and provide electrostatic shielding to suppress dendritic deposition. Through the cooperation of the cations and anions, we have realized Na metal electrodes that can be deeply cycled at a capacity of 10 mAh cm-2 for hundreds of hours.

Li2TiO3-Li4SiO4 biphasic ceramic pebbles have been developed as an advanced tritium breeder due to the potential to combine the advantages of both Li2TiO3 and Li4SiO4. Wet method was developed for the pebble fabrication and Li2TiO3-Li4SiO4 biphasic ceramic pebbles were successfully prepared by wet method using the powders synthesized by hydrothermal method. The tritium release properties of the Li2TiO3-Li4SiO4 biphasic ceramic pebbles were evaluated. The biphasic pebbles exhibited good tritium release property at low temperatures and the tritium release temperature was around 470 °C. Because of the isotope exchange reaction between H2 and tritium, the addition of 0.1%H2 to purge gas He could significantly enhance the tritium gas release and the fraction of molecular form of tritium increased from 28% to 55%. The results indicate that the Li2TiO3-Li4SiO4 biphasic ceramic pebbles fabricated by wet method exhibit good tritium release property and hold promising potential as advanced breeder pebbles.

As an advanced tritium breeder material for the fusion reactor blanket of the International Thermonuclear Experimental Reactor (ITER), Li 2 TiO 3 -Li 4 SiO 4 biphasic ceramic has attracted widely attention due to its merits. In this paper, the uniform precursor powders were prepared by hydrothermal method, and nanostructured 2Li 2 TiO 3 -Li 4 SiO 4 biphasic ceramic pebbles were fabricated by an indirect wet method at the first time. In addition, the composition dependence (x/y) of their microstructure characteristics and mechanical properties were investigated. The results indicated that the crush load of biphasic ceramic pebbles was better than that of single phase ceramic pebbles under identical conditions. The 2Li 2 TiO 3 -Li 4 SiO 4 ceramic pebbles have good morphology, small grain size (90 nm), satisfactory crush load (37.8 N) and relative density (81.8 %T.D.), which could be a promising breeding material in the future fusion reactor.

Flexibile high hydrolysis degree poly(vinyl alcohol) (PVA) films with different polyol plasticizers were obtained by melt processing in the presence of water, and the plasticizing effect of polyols was studied. The results showed that with the incorporation of polyols, the torque decreased, suggesting the improved melt flowing ability of PVA. Higher molecular weight polyols with more –OH groups exhibited higher efficiency to improve the melt flowing ability. The incorporation of polyol plasticizers did not change the crystalline structure of PVA but decreased crystalline degrees. The transmittance decreased with the increase in plasticizer content. The flexibility of PVA films was dramatically enhanced after being plasticized with polyols. The polyols with higher molecular weight possessed a higher stablity in PVA films and resulted in less weight loss during the thermal degradation process. It was suggested that a combination of different polyol plasticizers would be a better choice to obtain the PVA films with overall excellent properties.

Our previous study isolated a natural high-methoxyl homogalacturonan (HRWP-A) from Hippophae rhamnoides and showed antitumor activity in vivo. In this study, the immunomodulatory activity and mechanisms of action of HRWP-A were further investigated. Results showed that HRWP-A could recover the body condition and activated macrophage in Cyclophosphamide (CTX)-induced immunosuppressed mice. Further, we investigated the possible mechanism underlying the effects of HRWP-A on mouse peritoneal macrophages. qPCR and western blot revealed that HRWP-A upregulated the expression of TLR4 mRNA in vitro. This process was accompanied by a clear increase in MyD88 expression and p-IκB-α, but these effects were largely abrogated by pretreatment with anti-TLR4 antibodies. The effects of HRWP-A on macrophage NO, IL-1β and IL-6 production were also inhibited by anti-TLR4 antibodies and were greatly influenced by the NF-κB inhibitor PDTC. Moreover, HRWP-A failed to induce the production of NO, IL-1β and IL-6 in peritoneal macrophages prepared from C3H/HeJ mice, which have a point mutation in the Tlr4 gene, suggesting the involvement of the TLR4 molecule in HRWP-A-mediated macrophage activation. These results may have important implications for our understanding of the structure-activity relationship of immunopotentiating polysaccharides from medicinal herbs.

Probing and understanding surface restructuring-induced electrocatalytic reactivity is an essential but challenging step toward rational prediction of electrocatalytic properties and design of high-performance catalysts. Cobalt phosphide (CoP) nanoparticles are state-of-the-art electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). However, the structure–reactivity correlations are not straightforward because the nanoparticles will restructure under working conditions. Employing a protective sample transfer procedure, we use simple lab XPS to unveil the changes in oxidation state and composition of the nanoparticle surface induced by electrochemical reaction conditions. CoP nanoparticles are naturally oxidized on their surface. In alkaline electrolyte under HER conditions, a Co-rich phosphide surface is generated as a result of polyphosphate dissolution and reduction of the oxidized P and Co species. In alkaline electrolyte under OER conditions, an oxidati...