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Rank minimization is widely used to extract low-dimensional subspaces. As a convex relaxation of the rank minimization, the problem of nuclear norm minimization has been attracting widespread attention. However, the standard nuclear norm minimization usually results in overcompression of data in all subspaces and eliminates the discrimination information between different categories of data. To overcome these drawbacks, in this article, we introduce the label information into the nuclear norm minimization problem and propose a labeled-robust principal component analysis (L-RPCA) to realize nuclear norm minimization on multisubspace data. Compared with the standard nuclear norm minimization, our method can effectively utilize the discriminant information in multisubspace rank minimization and avoid excessive elimination of local information and multisubspace characteristics of the data. Then, an effective labeled-robust regression (L-RR) method is proposed to simultaneously recover the data and labels of the observed data. Experiments on real datasets show that our proposed methods are superior to other state-of-the-art methods.

Poor ductility is the primary concern of magnesium matrix composites (MMCs) inflicted by non-deformable ceramic particle reinforcements. Metal particles which melt at elevated temperature can be used as reinforcement to improve the deformation characteristics. Ti-6Al-4V particles reinforced AZ31 MMCs were produced through friction stir processing (FSP) which was carried out in a traditional vertical milling machine. The microstructural features as well as the response to external tensile load were explored. A homogenous distribution of Ti-6Al-4V was achieved at every part of the stir zone. There was no chemical decomposition of Ti-6Al-4V. Further, Ti-6Al-4V did not react with Al and Zn present in AZ31 alloy to form new compounds. A continuous strong interface was obtained around Ti-6Al-4V particle with the matrix. Ti-6Al-4V particles underwent breakage during processing due to severe plastic strain. There was a remarkable refinement of grains in the composite caused by dynamic recrystallization in addition to the pinning of smaller size broken particles. Dense dislocations were observed in the matrix because of plastic deformation and the associated strain misfit. Ti-6Al-4V particles improved the tensile behavior and assisted to obtain appreciable deformation before fracture. Brittle mode of failure was avoided.

Effect of sulfate-reducing bacteria on the corrosion behaviors of API-X80 pipeline steel has been studied in crevices under simulated disbonded coatings in red soil solution. The results show that there are amounts of SRB in the crevice under the simulated disbonded coating in the red soil solution during the whole period of experiment. The electrochemical impedance spectroscopy shows that SRB can enhance the corrosion of the steel in the crevice under the simulated disbonded coating, and the thermodynamic analyses indicate that SRB can accelerate the corrosion of steel using not only sulfate but also ferric hydroxide as electron acceptors.

Intrinsic partial occupation of Cu induces strong phonon scattering for an extremely low lattice thermal conductivity in TmCuTe2, which leads this material to be a promising candidate for thermoelectric applications. This work focus on the electronic and phononic transport properties of TmCuTe2 with Ag-alloying on the Cu site. Such a Ag/Cu substitution is found to enable a decrease in Hall carrier concentration from 14 × 1019 to 8 × 1019 cm−3 for an evaluation of the charge transport based on a single parabolic band (SPB) model with acoustic scattering. In addition, Ag-substitution simultaneously introduces Cu/Ag point defects for extra phonon scattering, leading the lattice thermal conductivity to be as low as ∼0.25 W/m-K in a broad temperature. The optimization in carrier concentration and the reduction in lattice thermal conductivity contribute to a ∼40% improvement in average thermoelectric figure of merit (zT). The determination of band parameters enables a guidance for further advancements in this promising thermoelectric material.

Li-rich layered oxides have attracted intense attention for lithium-ion batteries, as provide substantial capacity from transition metal cation redox simultaneous with reversible oxygen-anion redox. However, unregulated irreversible oxygen-anion redox leads to critical issues such as voltage fade and oxygen release. Here, we report a feasible NiFe2O4 (NFO) surface-coating strategy to turn the nonbonding coordination of surface oxygen into metal-oxygen decoordination. In particular, the surface simplex M-O (M = Ni, Co, Mn from MO6 octahedra) and N-O (N = Ni, Fe from NO6 octahedra) bonds are reconstructed in the form of M-O-N bonds. By applying both in operando and ex situ technologies, we found this heterostructural interface traps surface lattice oxygen, as well as restrains cation migration in Li-rich layered oxide during electrochemical cycling. Therefore, surface lattice oxygen behavior is significantly sustained. More interestingly, we directly observe the surface oxygen redox decouple with cation migration. In addition, the NFO-coating blocks HF produced from electrolyte decomposition, resulting in reducing the dissolution of Mn. With this strategy, higher cycle stability (91.8% at 1 C after 200 cycles) and higher rate capability (109.4 mA g-1 at 1 C) were achieved in this work, compared with pristine Li-rich layered oxide. Our work offers potential for designing electrode materials utilizing oxygen redox chemistry.

The water environment plays an essential role in the mangrove wetland ecosystem. Predicting water quality will help us better protect water resources from pollution, allowing the mangrove ecosystem to perform its normal ecological role. New approaches to solve such nonlinear problems need further research since the complexity of water quality data and they are easily affected by the noise. In this paper, we propose a water quality prediction model named CNN-LSTM with Attention (CLA) to predict the water quality variables. We conduct a case study on the water quality dataset of Beilun Estuary to predict pH and NH3-N. Linear interpolation and wavelet techniques are used for missing data filling and data denoising, respectively. The hybrid model CNN-LSTM is highly capable of resolving nonlinear time series prediction problems, and the attention mechanism captures longer time dependence. The experimental results show that our model outperforms other ones, and can predict with different time lags in a stable manner.

High-efficient heat dissipation is essential to maintain the best performance of the electron devices. A new electron thermal conductive route is first proposed and constructed for the graphene metal matrix composites in this work. Functionalization of graphene with conjugated 4-ethynylaniline (FGr) and deposition of FGr and Cu2+ ions onto the copper surface by pulsed-current co-electrodeposition are successively employed to prepare the FGr/Cu composite. The resulting thermal diffusivity of FGr/Cu is high as 1.444 cm2 s−1 at 100 °C, which is corresponding to the thermal conductivity of 497 W m−1 K−1 and higher than the reported values via single phonon thermal conductive route. FGr/Cu can maintain a superior and stable thermal conductive property at high temperature with a multiple of 1.61 and 1.31 at 100 °C and 150 °C compared to the Cu, respectively. The delocalized conjugated π bond in the graphene/Cu interface is successfully established through the bridging of graphene and metal with conjugated organic molecule possessing p orbits, which leads to the construction of a new electron thermal conductive route. This innovation presents an entirely new direction to develop graphene-based metal matrix composite with high-efficient heat dissipation.

In this work, MgCo2O4@NiMn layered double hydroxide (LDH) core-shell structured nanocomposites on Ni foam (NF) are synthesized by facile hydrothermal and calcination methods. MgCo2O4/NF is synthesized first via a hydrothermal reaction and annealing treatment, and then utilized to prepare MgCo2O4@NiMn-LDH/NF core-shell structured nanocomposites via the second hydrothermal process. It is found that the MgCo2O4@NiMn-LDH/NF nanocomposite prepared from 6 h hydrothermal reaction (MC@NM-LDH-2) exhibits an excellent specific capacitance of 3757.2 F g−1 (at 1 A g−1). Moreover, a high capacitance retention (86.9% after 6000 cycles) and a low internal resistance (Rs) (0.565 Ω) can be achieved. Furthermore, an all-solid-state asymmetric supercapacitor (ASC) is assembled using MgCo2O4@NiMn-LDH/NF-2 as positive electrode and activated carbon (AC) as negative electrode. The as-fabricated MgCo2O4@NiMn-LDH/NF-2//AC ASC shows a high energy density of 62.33 Wh kg−1 at 750 W kg−1. Meanwhile, the MgCo2O4@NiMn-LDH/NF-2//AC ASC device possesses an outstanding cycling stability of 93.7% retention of the initial capacitance after 6000 cycles and three ASC devices connected in series can light up a LED bulb for 15 min. Our results manifest that these core-shell structure MgCo2O4@NiMn-LDH nanocomposites could envision huge potential application in energy storage devices.

The determination of changes in hydrogeological properties (e.g., permeability and specific storage) of aquifers disturbed by mining activity is significant to groundwater resource and ecological environment protection in coal mine areas. However, such parameters are difficult to continuously measure in situ using conventional hydrogeological methods, and their temporal changes associated with coal mining are not well understood. The response of well water level to Earth tides provides a unique probe to determine the in situ hydrogeological parameters and their variations. In this study, the tidal responses of well water level were employed to characterize the changes in hydrogeological parameters of the overburden aquifer induced by longwall mining in a coalfield, northwest China. Based on the long-term hourly recorded water level data, two analytical models were used to determine the temporal changes of permeability and specific storage of the overburden aquifer. The results showed that the hydrogeological parameters changed with the longwall coal face advance. When the longwall coal face approached the wells, the aquifer permeability increased several to dozens of times, and the response distance ranged from 80 m to 300 m. The specific storage decreased before the coal face reached wells and recovered after the coal face passed. The results of this study indicate that the hydrogeological parameter changes induced by coal mining are related to the location of the well relative to the coal face and the stress distribution in the overburden aquifer. This study revealed the changes in permeability and specific storage associated with the mining disturbance which could have great significance for quantitative assessment of the impact of mining on overburden aquifer.

The practical applications for the distinctive functions of metamagnetic Heusler alloys, such as magnetic shape memory effect, various caloric effects, etc., strongly depend on the phase transition temperatures. Here, flexible Heusler alloy Ni-Mn-Sn films have been deposited on mica substrates by pulsed laser deposition with a Ti buffer layer. Clear ferromagnetic (FM) transition followed by the martensitic transformation at around room temperature and exchange bias (EB) with a blocking temperature of 70 K are observed. Under the application of both tensile and compressive strains by bending the mica substrates, all the characteristic temperatures of Ni-Mn-Sn films, including the FM transition temperature, martensitic transformation temperature, and blocking temperature of EB, are significantly increased by about 10 K. Furthermore, EB field and coercivity are both strongly strengthened, which is mainly caused by the simultaneous enhancement of FM and anti-FM Mn-Mn coupling because of their shortened separations by strain and verified by the Monte Carlo simulation results. The strain controlling for structural and magnetic properties provides efficient manipulation for Heusler alloy-based magnetic devices.

Summary Production of the high‐value carotenoid astaxanthin, which is widely used in food and feed due to its strong antioxidant activity and colour, is less efficient in cereals than in model plants. Here, we report a new strategy for expressing β‐carotene ketolase and hydroxylase genes from algae, yeasts and flowering plants in the whole seed using a seed‐specific bidirectional promoter. Engineered maize events were backcrossed to inbred maize lines with yellow endosperm to generate progenies that accumulate astaxanthin from 47.76 to 111.82 mg/kg DW in seeds, and the maximum level is approximately sixfold higher than those in previous reports (16.2–16.8 mg/kg DW) in cereals. A feeding trial with laying hens indicated that they could take up astaxanthin from the maize and accumulate it in egg yolks (12.10–14.15 mg/kg) without affecting egg production and quality, as observed using astaxanthin from Haematococcus pluvialis. Storage stability evaluation analysis showed that the optimal conditions for long‐term storage of astaxanthin‐rich maize are at 4 °C in the dark. This study shows that co‐expressing of functional genes driven by seed‐specific bidirectional promoter could dramatically boost astaxanthin biosynthesis in every parts of kernel including embryo, aleurone layer and starch endosperm other than previous reports in the starch endosperm only. And the staple crop maize could serve as a cost‐effective plant factory for reliably producing astaxanthin.

Fast pyrolysis of the mixed plastics (PE: PP: PS: PVC = 0.5: 0.3: 0.15: 0.05) with and without hydrothermal dechlorination pretreatment were investigated in a fixed bed reactor to determine the effects of pyrolysis parameters (temperature, carrier gas flow rate and particle size) on the distribution and the quality of the products. The results showed that high pyrolysis temperature, high carrier gas flow rate and small particle size promoted the migration of organic chlorine in condensable products to inorganic chlorine in gas products. And the optimal conditions for fast pyrolysis of mixed plastics to produce oil were the pyrolysis temperature of 500 °C, carrier gas flow rate of 40 ml/min and particle size of 0.1–0.15 mm with the maximum oil yield of 67.88 wt%. Hydrothermal pretreatment of mixed plastics has shown an excellent dechlorination efficiency of 99.9 %. Furthermore, the total yield of oil and wax was increased by 7.06 wt%, meanwhile the content of C5-C9 components in the pyrolysis oil showed an upward trend when compared with fast pyrolysis without pretreatment. Besides, the concentration of methane achieved 50.68 % due to the possible weakening effect of hydrothermal pretreatment on C C bond energy of β-position.

Computation of traveltimes and raypaths is important for anisotropic tomography inversions. The eikonal-equation-based method outperforms traditional ray methods by producing more accurate results. However, most existing eikonal solvers are formulated on structured regular meshes, which are no longer accurate for models with the presence of irregular topography and subsurface interfaces. To solve the eikonal equation in vertically transversely isotropic (VTI) or tilted transversely isotropic (TTI) models with irregular geometry, we have formulated a new iterative fast sweeping method (FSM) on unstructured triangular meshes. The fixed-point iteration is implemented to capture the high-order nonlinear terms therein, and an FSM on unstructured triangular meshes is implemented to solve the resulting elliptically anisotropic eikonal equation at every iteration. We test the new algorithm for direct arrivals and reflected arrivals, and then we use the calculated traveltimes to track the raypath in VTI/TTI media. Numerical tests demonstrate the validity and accuracy of the new method for models with rough topography and subsurface interface.

Vegetable industry occupies a significant position in the world agricultural production, China has been the largest vegetable producing country in the world. However, the mechanization of vegetable production is still in the initial stage. There are many problems such as complex environment, non-uniform agronomy, various kinds of agricultural machinery etc. In order to meet the varied requirements of vegetable field work, in this paper, a new type of high-efficiency vegetable field operation power equipment was developed by adopting the idea of "frame-type", and the key components are developed. They include ground gap adjusting mechanism, wheel spacing adjusting mechanism, inter-axle hitch mechanism, the rear hitch mechanism and frame. The vibration modal analysis and stiffness analysis of the frame are carried out by ANSYS, which proves that the frame design is reasonable and meets the use requirements. Finally, a prototype was made and field experiments were carried out. The results showed that the maximum running speed of the multifunctional vegetable field machine was 16 km/h, the maximum operating speed was 8 km/h, the maximum gradient was 20, and the adjustable range of ground clearance was 400~800 mm. The adjustable range of wheel spacing was 1600-2000 mm.

Stimuli-responsive hydrogels are flourishing; however, a multiresponsive luminescent hydrogel actuator in which the stimuli do not interfere with each other is still difficult to produce. Here, a smart luminescent bilayer hydrogel actuator with shape memory and reversible luminescence switch behaviors under the co-stimulation of pH and heating is reported. Under alkaline condition, chitosan-containing layer generates physical microcrystals to fix the temporary shape of the actuator while lanthanide emits bright luminescence. Upon acid treatment, the actuator recovers to its original shape and the luminescence is quenched since the "antenna effect" between organic ligand and lanthanide ions is disrupted. It is to be noticed that this multiresponsive cycle can be repeated several times without interfering each other. This work is expected to have potential application prospects in the fields of biomimetic soft robots, sensors, and camouflage.

The continuous degradation of carbonate electrolytes and the dissolution of transition metal cations due to parasitic reactions on the cathode-electrolyte interphase (CEI) block the practical application of LiNi0.5Mn1.5O4-based lithium-ion batteries (LNMO-based LIBs) at a high voltage. cis-1,2,3,6-Tetrahydrophthalic anhydride (CTA) has been used as a functional additive in a carbonate baseline electrolyte (BE) for constructing the CEI film to enhance the cyclic stability of LNMO-based LIBs. The LNMO/Li cell with CTA exhibits a preponderant capacity retention of 83.3% compared with those of propionic anhydride (PA) (46.5%) and BE (13.6%) after 500 cycles at the current density of 1 C from 3.5 to 4.9 V. Additionally, the LNMO/graphite full cell with CTA still has a higher capacity retention of 95.46% even after 300 cycles at 1 C. By characterizations, it is reasonably demonstrated that CTA was oxidated to participate in the construction of a CEI film. An unsaturated aromatic group was introduced into the composition of the CEI film along with CTA in the formation process of the CEI film, which further improved the antioxidative activity of the CEI film under the influence of field-effect. Specifically, the CEI film obtains appreciable stability because of its higher antioxidative activity under the influence of field-effect. The stabilized CEI can significantly suppress the parasitic reactions of electrolytes, decrease the consumption of active-Li+, and protect the LNMO cathode structure, thereby enhancing the cyclic compatibility of LNMO-based LIBs with the carbonate electrolytes from 3.5 to 4.9 V.

Novel CaAl2xB2O4+3x (x = 0.25, 0.5, 0.75, and 1) ceramics were prepared via solid-state reaction method. The investigation is concentrated on sintering behavior, phase composition and dielectric properties of CaAl2xB2O4+3x ceramics with various ratios of Al2O3 content. The optimal sintering temperature and the content of CaAl2B2O7 are highly related to the variation of x value. CaAl2xB2O4+3x ceramics possess excellent microwave dielectric properties: er = 5.8 ± 0.05, Q × f = 63,338 ± 2690 GHz (@13.57 GHz), and τf=-29 ± 2 ppm/℃ when sintered at 940 ℃ for x = 0.5. Comparing the properties of CaAl2xB2O4+3x ceramics with reported borate ceramics, the ceramics prepared in this study with low dielectric loss and low sintering temperature have promising prospects in LTCC technology.

A MoSi2 coating was prepared on the Mo1 wire mesh via pack cementation method, and its failure mechanisms under isothermal oxidation and hot-fire test using a hydroxylammonium nitrate based monopropellant were comparatively studied. Under isothermal oxidation at 1300 °C and 1400 °C, degradation of MoSi2 into Mo5Si3 caused failure of the coating, and interdiffusion made a much larger effect relative to oxidation. However, the MoSi2 coating failed because of the synergy of oxidation, ablation, and interdiffusion under hot-fire test. Besides, dissolution of mullite into SiO2 and ablation of high velocity flame contributed to the failure of the coating as well.

Sustainable transportation is one of the solutions to global warming because road transport is responsible for a considerable part of the total carbon emissions. Electric vehicle (EV) technology is still developing, and most of the available brands market them as either environmentally friendly or operationally economical compared to internal combustion engine based traditional vehicles. However, the adoption rates of electric vehicles across the globe are meager. Customer engagement (CEN) is one of the emerging concepts for gaining and retaining users of a product. This research analyzes CEN in EVs based on more engaging features and technologies, i.e., smart connectivity features. Unfortunately, this vital research area remains unexplored in academia. The role of customer experience and customer brand value is also analyzed in relation to smart connectivity features and CEN. The study uses partial least square-based structural equation modeling to analyze the collected data through a web-based survey. The results show that smart connectivity features have a significant positive impact on CEN in EVs. Smart connectivity features also have a significant indirect effect on CEN through customer experience. Further, customer brand value has a direct impact on customer experience, and customer brand value also has a significant indirect effect on CEN in EVs. These results have significant theoretical and managerial implications.

In this paper, we report the finding and basic characterization of a new multiferroic material in the form of the Y2FeAlO6 (YFAO) double perovskite with orthorhombic structure. In order to study the structural and multiferroic properties in detail, we prepared the polycrystalline YFeO3 (YFO) and Y2FeAlO6 ceramic samples through traditional high temperature solid-state reaction method. XRD analysis confirmed that these two samples are single-phase and all the peaks in the pattern can be indexed with orthorhombic symmetry of the Pnma space group. Compared to YFO, YFAO is more symmetric, and has a more stable crystalline structure and smaller grain size. The Fe ion in YFO and YFAO are in the mixed oxidation state of Fe2+ and Fe3+, while the relative amount of Fe2+ in YFAO is higher than that of YFO. Al3+ with filled 2p orbital and grain refinement may be the main reasons for the greatly enhanced multiferroicity of YFAO. The magnetic properties of YFO and YFAO are mainly dominant antiferromagnetism and weak ferromagnetism, and the exchange bias effect disappears in YFAO. The coexistence of ferroelectricity and ferromagnetic orders at room temperature in YFAO promises new opportunities and improvements in next generation applications for spintronic, information storage, and sensors etc.

The orbital angular momentum (OAM)-based acoustic vortex (AV) communication has been proven to provide a topological spinning characteristics for data transmission with an improved channel capacity, exhibiting good application prospects in underwater acoustic communications. To improve the accuracy and efficiency of data communication, the spectrum decomposition of OAM modes for OAM-multiplexed AV beams is studied with a simplified structure of single-ring transceiver arrays. The principle of spectrum decomposition for the single-OAM or OAM-multiplexed AV beams is derived based on the phase-coded approach and the orthogonal property of AVs. With the single-ring arrays of 16 transducers and 16 receivers, numerical studies and experimental measurements of eight-OAM-multiplexed AV beams transmitting ASCII codes are conducted. The formation of OAM-multiplexed AV beams is demonstrated by the cross-sectional scanning measurements, and the OAM modes are decoded successfully with a 16-point circular sampling. Compared with the traditional orthogonality-based decoding algorithm, the spectrum decomposition can be realized using a rotational measurement without the multiple premeasurements of single-OAM AV beams. The favorable results demonstrate the feasibility of the spectrum decomposition-based OAM communication for AV beams using a simplified structure of single-ring transceiver arrays, which would facilitate the practical application in underwater communications.

A facile synthetic route was developed to prepare a surface-grafted brush layer of poly(vinyl ethers) (PVEs) directly by a radical mechanism, with the "naked" Li+ acting as a catalyst. Density functional theory calculations suggested that complexation of naked Li+ to VEs significantly reduced the highest unoccupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy gap from 5.08 to 0.68 eV, providing a better prospect for electron transfer. The structure, morphology, and surface properties of grafted polymer layers were characterized using attenuated total reflection Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and dynamic water contact angle (DCA). Moreover, ellipsometry data indicated that the thickness of the polymer brushes was in the range of 20-60 nm, which corresponds to the grafting densities of 0.65-1.15 chain/nm2, and DCA decreased from 84.4 to 45.3°. Most importantly, no hydrolysis was observed for the modified surface after 30 days of exposure to phosphate-buffered saline solution, 0.1 mol/L NaOH(eq) and 0.1 mol/L HCl(eq), demonstrating excellent hydrolysis resistance with long service life. In addition, as a proof of concept, the side hydroxyl groups of grafted PVEs provide active sites for efficient fixation of bioactive molecules, e.g., glycosaminoglycan and serum protein.

Titanium alloy Ti-6Al-4V particles were used as reinforcement for AZ31B magnesium metal matrix composites (Mg MMCs) which were synthesized via friction stir processing (FSP). Ti-6Al-4V particulates were packed in the machined grooves at first and subsequently processed by means of a traditional machine used for vertical milling. The processing speed and the repeated passes were considered as the major processing factors to vary during processing apart from the content of Ti-6Al-4V particles. Optical and scanning electron microscopes were used to record the evolved microstructure of the composites. Changes in Ti-6Al-4V particle distribution across the stir zone resulted to form several kinds of microscopic regions. The distribution of particles became inhomogeneous as the traverse speed was advanced to higher level. Conversely, the distribution became homogeneous with every pass. The role of selected process variables on the tensile behavior was analyzed. Mg MMCs that were prepared at lower traverse speed (30 mm/min) and higher number of passes (5) showed higher properties during tensile test. The micrographs of the fracture surfaces were studied to understand the mode of fracture.

PurposeSustainability failures have increased the pressure for manufacturing firms to come up with innovative solutions to resolve the sustainable matters. Drawing on the resource-based theory, the purpose of this study is to examine how supply chain visibility moderates the effects of sustainable practices on sustainable performance.Design/methodology/approachThe data employed in the current work were collected from 355 small and medium manufacturing firms in Pakistan using a structured questionnaire. The structural equation modelling was applied to the collected data with AMOSS-23 and SPSS-25 packageFindingsThe results show that sustainable practices (for manufacturing, procurement and distribution) significantly influence the firm's sustainability performance, and this relationship is moderated by supply chain visibility.Originality/valueSustainable practices are necessary for small and medium enterprises to achieve sustainable performance, but the previously under-explored moderating effect of supply chain visibility generally indicates that sharing information for learning, sensing and co-ordinating activities plays an intensifying effect.

Background Bisphenol A (BPA) is a plasticizer with high production and ubiquitous usage in polycarbonate plastics and epoxy resins. The association between prenatal or postnatal exposure to BPA and childhood wheeze/asthma has not been well established. Our study aimed to provide further justification for the current studies. Methods Studies were searched from PubMed, Web of Science, Scopus and Embase from inception until Sep 15, 2020. Meta-analysis was performed to calculate pooled adjusted odds ratios (aOR). The methodological quality of included studies was assessed by using the Newcastle Ottawa Scale (NOS). Results Of 2,814 screened articles, 9 studies with 3,885 participants were included in the final analysis. When all studies were pooled, postnatal exposure to BPA was associated with a higher risk of childhood asthma (aOR =1.43; 95% CI: 1.28-1.59) or childhood wheeze (aOR =1.38; 95% CI: 1.18-1.62). Prenatal exposure to BPA had a small but significant increased risk of childhood asthma (aOR =1.17; 95% CI: 1.01-1.34). An increased risk of childhood wheeze was related to prenatal exposure to BPA at 16 weeks' gestation (aOR =1.29; 95% CI: 1.07-1.55), but not at 26 weeks' gestation (aOR =1.07; 95% CI: 0.88-1.29) nor at random-time gestation (aOR =1.02; 95% CI: 0.89-1.16). Conclusions Prenatal and postnatal exposure to BPA was related to an increased risk of childhood asthma. However, only postnatal and early gestational exposure (at 16 weeks) to BPA could induce the risk of childhood wheeze, but not late gestational exposure (at 26 weeks).

This paper discusses how the pollution prevention mandate imposed by China's central government triggers water pollution across provincial borders. Because the central government has put the pollutant reduction into the promotion evaluation, and pollution control in the downstream area of a province mainly brings benefit to other regions, the provincial officials are incentivized to reduce the water pollutants away from the downstream city and strengthen environmental regulation within the province. We apply the difference-in-differences-differences (DDD) method to the dataset on water quality in cities along 18 major rivers in China from 2007 through 2016. We find that compared with the interior cities, the most downstream city of a province faces worse water quality. Besides, we find that environmental policy significantly increases the extent of pollution across jurisdictional boundaries. Then, we turn on the mechanism and find that the pollutant reduction target is significantly lower in the most downstream city of a province. Unanticipated provincial government behavior leads to severe transboundary water pollution.

This study presents the formation mechanism of a layered structure consisting of coherent cellular and columnar solidification microstructure accompanied with the macrosegregation in aluminum dissimilar-filler welding. The filler-depleted zone resulted from the incomplete mixing of the solute; moreover, it solidifies before the surrounding mixed zone, wherein the subsequent dendritic growth is hindered by the pre-solidified microstructure. This solidification sequence leads to a layered solidification microstructure and segregation patterns.

Biomarkers based on DNA methylation have attracted wide attention in biomedical research due to their potential clinical value. Therefore, a sensitive and accurate method for DNA methylation detection is highly desirable for the discovery and diagnostics of human diseases, especially cancers. Here, an integrated, low-cost, and portable point-of-care (POC) device is presented to analyze DNA methylation, which integrates the process of pyrosequencing in a digital microfluidic chip. Without additional equipment and complicated operation, droplets are manipulated by patterned electrodes with individually programmed control. The system exhibited an excellent sensitivity with a limit of detection (LOD) of 10 pg and a comparable checkout down to 5% methylation level within 30 min, which offered a potential substitute for the detection of DNA methylation. With the advantages of portability, ease of use, high accuracy, and low cost, the POC platform shows great potential for the analysis of tumor-specific circulating DNA.

Heterostructured photocatalysis is a significant issue owing to the unique band alignment, improved spectrum absorption, and enhanced photocatalytic activity. However, the construction of uniform, controllable, and effective heterojunctions is still a huge challenge. Herein, NaNbO3 /Nb3 O7 F heterojunctions are fabricated through an in situ corrosion technique for the first time. The influence of phase transformation on the hydrogen evolution reaction (HER) activity is investigated systematically in terms of photocatalytic water splitting for H2 production. Interestingly, the band realignment and good interfacial contact endow the NaNbO3 /Nb3 O7 F heterojunctions with a high HER activity (43.3 mmol g-1 h-1 ), which is about 2.4 times that of pure Nb3 O7 F and 1.36 times that of pure NaNbO3 . The results may provide some new insights into the corrosion technique and HER activity of novel heterostructured catalysts.

Three new emitters, namely 10,10'-(quinoline-2,8-diyl)bis(10H-phenoxazine) (Fene), 10,10'-(quinoline-2,8-diyl)bis(10H-phenothiazine) (Fens) and 10,10'-(quinoline-2,8-diyl)bis(9,9-dimethyl-9,10-dihydroacridine) (Yad), featuring quinoline as a new electron acceptor have been designed and conveniently synthesized. These emitters possessed small singlet–triplet splitting energy (ΔEst) and twisted structures, which not only endowed them show thermally activated delayed fluorescence (TADF) properties but also afforded a remarkable aggregation-induced emission (AIE) feature. Moreover, they also showed aggregation-induced delayed fluorescence (AIDF) property and good photoluminescence (PL) property, which are the ideal emitters for non-doped organic light-emitting diodes (OLEDs). Furthermore, high-performance non-doped OLEDs based on Fene, Fens and Yad were achieved, and excellent maximum external quantum efficiencies (EQEmax) of 14.9%, 13.1% and 17.4%, respectively, were obtained. It was also found that all devices exhibited relatively low turn-on voltages ranging from 3.0 V to 3.2 V probably due to their twisted conformation and the AIDF properties. These results demonstrated the quinoline-based emitters could have a promising application in non-doped OLEDs.

Because of its unique geographical location and ecological function, the Liaohe Delta Wetland is important in maintaining regional ecological balance and security. Monitoring and evaluating changes in the wetland are therefore of great importance. We used medium- and high-resolution satellite data, meteorological station data, and site measurement data to analyze changes in the area and spatial distribution of Phragmites australis and Suaeda salsa in the Liaohe Delta Wetland from 1998 to 2017, as well as their growth response to the climate change. The results showed that during 1998–2017, the areas of both P. australis and S. salsa wetlands alternated through periods of decreasing, increasing, and then decreasing trends. The annual change in the area and spatial distribution range of S. salsa fluctuated more than that of P. australis. The annual variation of normalized difference vegetation index (NDVI) in P. australis wetland showed an upward trend from 1998 to 2017. The area of P. australis cover that was improved, unchanged, and decreased accounted for 81.8%, 12.3%, and 5.9%, respectively, of the total area; evaporation and wind speed were the main meteorological factors affecting the NDVI; and contribution rates of the climate change and human activities to the NDVI were 73.2% and 26.8%, respectively. The area with vegetation cover being mainly S. salsa that was improved, unchanged, and decreased accounted for 63.3%, 18.3%, and 18.4%, respectively, of the total area; and no meteorological factors significantly affected the NDVI of S. salsa in the region. The interaction between vegetation growth and meteorological factors may help to explain the increasing trend in vegetation cover. The improvement in wetland vegetation also led to carbon sequestration and an increase in sequestration capacity.

Skotomorphogenesis occurs after germination and before excavation in plants. It inhibits excessive absorbed energy in cells and can prevent the lethal photooxidative damage caused by transitioning from skotomorphogenesis to photomorphogenesis for light energy utilization. To investigate the mechanisms underlying photoreactions in soybean [Glycine max (L.) Merr.], we identified and isolated soybean phytochrome-interaction factor 1 (GmPIF1). A yeast two-hybrid (Y2H) assay showed that GmPIF1 interacted with photoactive PHYTOCHROME A (PHYA) and B (PHYB) in both soybean and Arabidopsis (GmPHYA, GmPHYB, AtPHYA, and AtPHYB). To analyze its function, we ectopically over-expressed GmPIF1 in wild type and pif1 mutant Arabidopsis. In etiolated seedlings, GmPIF1 caused hypocotyl elongation, cotyledon closed, apical hooks folded, and less accumulation of protochlorophyllide. In Y2H, GmPIF1 interacted with AtHDA15 that inhibited chlorophyll synthesis under dark conditions. After transition from darkness to white light, GmPIF1 promotes the reduction of photobleaching and induced de-etiolation. Moreover, GmPIF1 inhibited PHYA- and PHYB-mediated seed germination. Our findings increase our understanding of the regulatory network of light response in soybean and provide useful gene resources for soybean breeding in programs and genetics engineering.

Astragalus sinicus is a commonly used legume green manure that fixes atmospheric N2 and accumulates mineral nutrients and organic substances that are beneficial to soils and subsequent crops. However, little is known about genotypic variation in, and molecular mechanisms of, Pi (phosphate) uptake and storage in A. sinicus. We recorded the morphological responses of six A. sinicus cultivars from four regions of China to external Pi application and measured their Pi accumulation. We identified full-length transcripts of Pi-signaling and Pi-homeostasis regulators by sequencing and measured the expression level of these genes by qRT-PCR. The major components in Pi signaling and Pi homeostasis were largely conserved between A. sinicus and the model species rice and Arabidopsis. Different A. sinicus varieties responded differently to low-phosphorus (P) stress, and their Pi accumulation was positively correlated with the expression of vacuolar Pi influx gene (SYG1/PHO81/XPR1-MAJOR FACILITATOR SUPERFAMILY (SPX-MFS)-TYPE PROTEIN) AsSPX-MFS2 and negatively correlated with the expression of the vacuolar Pi efflux gene (VACUOLAR Pi EFFLUX TRANSPORTER) AsVPE1. We identified key Pi-signaling and Pi-homeostasis regulators in A. sinicus. The expression of vacuolar Pi transporter genes could be used as an index to select A. sinicus accessions with high Pi accumulation.

Carbon nanotubes (CNTs) are regarded as the next generation of one-dimensional super-strong nanomaterials due to their extraordinary mechanical properties. Recently, much attention has been dedicated into super-strong CNT-based fibers resulting from twisting operation. However, the roles of a promising compression operation on the mechanical enhancement mechanisms of CNT fibers (CNFs) are not clear. Especially, the combined twisting-compression effect has not been known. In this work, with using coarse-grained molecular dynamic simulation method, the tensile mechanical properties and mechanical enhancements of randomly-distributed CNT fibers (RDCNFs) were studied. It was found that the mechanical performances of such RDCNFs could be significantly improved by increasing CNT length or decreasing initial bending degree of CNTs. Furthermore, both specific strength and specific modulus can be effectively tuned by twisting and compressing operations, where self-locking and unhitching mechanisms of CNT knots play critical roles. On the other hand, following theoretical guidance, a super-strong CNF with the maximum specific strength up to 296 mN/tex (∼6.8 GPa) was designed and fabricated. This work provides a theoretically and experimentally support to design super-strong CNT-based fibers and lays a foundation for their future applications.

Enhancing the mechanical strength of highly conductive pure metals usually causes significant reduction in their electrical conductivity. For example, introducing phase/matrix interfaces or more grain boundaries, are common and effective methods to strengthen metals. But it simultaneously increases the electron scattering at the interface, thus reducing the electrical conductivity. In this study, we demonstrate that pure aluminum (Al)/carbon nanotubes (CNTs) nanocomposites prepared by friction stir processing have successfully broken through these limitations. The yield strength and tensile strength of Al/CNTs nanocomposites have improved by 104.7% and 51.8% compared to pure Al, while the electrical conductivity remained comparable to that of pure Al. To explore the potential mechanisms, the interface between CNTs and Al was examined and characterized by transmission electron microscopy (TEM) and Raman spectroscopy. Little interfacial reaction compounds were present and no visible physical gaps were observed at CNTs and Al interfaces. We defined it as a clean and tightly bonded interface. Although the quantity of phase interface has increased, the electrical conductivity of the nanocomposite remains approximately unchanged. We attribute the preserved electrical conductivity to the clean and tightly bonded CNTs/Al interface in the nanocomposite.

In order to calculate the spatial distribution of high-resolution air-pollutant levels, the land use regression (LUR) model can be an effective method due to the comprehensive consideration of various factors. Traditional LUR models mostly use predefined buffers, which have the disadvantage of not matching high-resolution data well. In order to get a better-fitting model, a few researches have proposed new buffer selection methods. To solve this problem, we propose a new optimal buffer selection method based on the dichotomy to improve the correlation between predicted variables and pollutant concentration. For some socioeconomic data with high spatial resolution that cannot be obtained, for example, building data is used instead of population density data. Compared with the model with the predefined buffers, the model with our buffer selection strategy explained additional 5% variability in measured concentrations, in terms of the R2 of the final model. Our model explained 98% of the samples, and the deviation (1.78%) and root mean square error (5.17 μg/m) were small. It means that the LUR model with our buffer selection strategy can be used as a fit method to better describe spatial variability in atmospheric pollutant levels, which will be conducive to epidemiological research and urban environmental planning.

Emission forecasting is vital for policy-making and emission reduction goals globally. This research aimed to perform an accurate model for forecasting and assessing CO2 emissions and the production of renewable electricity for the top two countries contributing to these emissions, the USA and China. In this study, we employed three novel advanced mathematical grey models: optimized discrete grey model (ODGM), nonhomogeneous discrete grey model (NDGM), and variable speed and adaptive structure grey model (VSSGM) to estimate the future trends of CO2 emissions and renewable electricity production. These breakthrough models added value in this field of research by reducing uncertainty surrounding ambiguity and numerical ranges and improving accuracy in assessments by using small samples and imperfect information. The findings showed that, by 2026, China's electricity production based on renewable sources would be higher than that of the USA. We find CO2 emissions in a downward trend, with more significant reductions in the USA than in China by the year 2026. The contributions of this study are the application of novel VSSGM and the use of synthetic relative growth rate modeling for predicting the overall growth of CO2 emissions and the production of renewable electricity in analyzed countries. The originality of this study lies in proposing a novel synthetic doubling time model to compute how long it will take, for China and the USA, to reduce their CO2 emissions and doubling their increase in renewable electricity production.

The big data revolution has created data center sustainability problems, whose solutions require the consideration of environmental factors. The purpose of this study is to establish a big data center sustainability evaluation index and provide guidance for sustainable data center construction. This research formulated a big data center sustainability evaluation model that integrates multiple-criteria decision-making methods based on the analytic network process and fuzzy technique for order preference by similarity to an ideal solution (TOPSIS). Furthermore, a case study was used to examine the proposed model. The refrigeration system, layout and ventilation, data center location, data volume, and server power consumption are the five most crucial factors in determining the sustainability level of a big data center. The areas that require further development are the balancing of tasks on different IT equipment, renewable energy use, and waste heat utilization. This research provides a method or guide that can be used by managers when they build new big data centers or upgrade and optimize existing big data centers to make them more sustainable. This study is the first to assess the sustainability of a big data center according to multiple criteria decision-making methods, in which fuzzy theory is applied to evaluate the imprecise and subjective judgments of decision-makers. This study provides a systematic evaluation framework that is based on qualitative and quantitative criteria and comprises the four factors of big data level, equipment level, room level, and data center level. Big data is new oil, but it is not clean oil. It is both a vital driver of economic growth and a source of environmental damage. We need to ensure that big data centers are run in a sustainable way.

Developing low-cost and highly active hydrolysis catalytic materials for the dehydrogenation of hydrogen-rich chemicals is a promising strategy to store and easily release hydrogen for fuel cell applications. In this study, new bimetallic hybrid nanoplates containing Co3O4 and CuCoO2 were developed via a facile and low-cost approach for catalytically producing hydrogen from ammonia borane (NH3BH3). The as-prepared efficient Co3O4–CuCoO2 material was employed as a catalyst for NH3BH3 hydrolysis, and it exhibited a high catalytic performance with a turnover frequency (TOF) of 65.0 molhydrogen molcat.−1 min−1 at room temperature. The results revealed that the hybrid Co3O4–CuCoO2 catalysts exhibited much improved catalytic activity towards the hydrolysis reaction in contrast to the individual Co3O4 and CuCoO2 catalysts. A kinetic study showed that the Co3O4–CuCoO2 catalytic material had superior activity with an apparent activation energy (Ea) of 20.5 kJ mol−1, which was found to be one of the lowest Ea for NH3BH3 hydrolysis ever reported in the literature. This work provides a promising approach for the synthesis of noble metal-free catalysts exhibiting high catalytic activity towards NH3BH3 hydrolysis.

Compressed sensing with a tunable random sampling strategy has great potential in reducing the energy/time consumption during the constant acquisition of external information, thereby it is considered one of the most promising sensing strategies in edge-terminal. In this letter, a novel tunable stochastic oscillator (TSO) based on the VO2/TaOx structure was proposed and employed as the core controlling device for compressed sensing. The TSO is jointly governed by the metal-insulator-transition (IMT) based threshold switching of the VO2 layer and the stochastic resistive switching by the TaOx layer. The tunable memristor/resistor in series can modulate the oscillation frequency of the TSO. The orthogonal matching pursuit (OMP) algorithm is implemented to reconstruct the compressed sparse signals, demonstrating a good performance of TSO in compressed sensing.

In this study, Sm3+/Tb3+-co-doped NaGd(MoO4)2 phosphors were prepared via the hydrothermal method, with sodium citrate used as a chelator. X-ray diffraction confirmed the structure of the samples, and the test outcomes showed that the phosphors exhibited a body-centered tetragonal structure. Field-emission scanning electron microscopy results showed that the specimen morphology changed with the change in the Cit3−/Re3+ molar ratio. Moreover, the measured temperature-dependent emission spectra showed that Sm3+ and Tb3+ had different quenching trends; thus, the fluorescence intensity ratio can be used to represent temperature. In addition, the outcome of this experiment revealed that the temperature-sensing sensitivity of the phosphors gradually increased with the increasing Cit3−/Re3+ ratio, and the highest sensitivity value was 0.346 K−1 (at 503 K, Cit3−/Re3+ = 2). When the temperature was 298–369 K, the temperature-sensing relative sensitivity increased with increasing Cit3−/Re3+, but in the range 374–503 K, the relative sensitivity decreased with increasing Cit3−/Re3+. The highest relative sensitivity value of the sample was 2.7% K−1 (404 K, Cit3−/Re3+ = 0). Additionally, the Commission International del’Eclairage chromaticity coordinates displayed that the luminous colors of Sm3+/Tb3+-co-doped specimens continuously changed from green to red as the temperature changed.

Rational interface control of porous carbon electrode materials is of significance for achieving efficient supercapacitors. Herein, biomass-derived carbon microspheres with a highly graphitized porous surface and amorphous subsurface were well constructed via a flexible coupled catalysis-activation process. The unique structure not only endows the carbon microspheres with rapid electron transfer but also an ultra-high specific surface area. Owing to the optimized graphitized/amorphous structure, the obtained graphitized and activated starch-derived carbon microspheres display obviously impressive energy storage capability among the reported starch-derived carbon materials, even though they were evaluated in a narrow voltage window. The assembled symmetrical supercapacitor based on the optimized carbon microspheres exhibits a high capacitance of 198 F g−1 at 1 A g−1, a high energy density of 14.67 W h kg−1 at a power density of 4142.80 W kg−1, robust cycle performance, and good rate performance in alkaline aqueous electrolyte. This work provides a strategy for flexible construction of biomass-derived carbon electrode materials, with an optimized graphitized/amorphous and porous structure, for boosted energy storage in supercapacitor applications.

Raman spectroscopy can provide structural fingerprints to identify molecules by means of spectral library searching. However, it is difficult to share the spectral library between different Raman spectrometers because of the nonlinear displacement in Raman shift. In this study, we propose a Raman spectra Standardization method using Variable Penalty dynamic time warping (RS-VPdtw), which can synchronize the nonlinear displacement between spectra acquired with different spectrometers. We have compared the standardization performance of RS-VPdtw and MWFFT on the spectra of 13 real samples acquired with 6 different spectrometers. The mean spectral similarity of RS-VPdtw and MWFFT increased from 0.79 to 0.97 and 0.91 respectively. Results show that RS-VPdtw is significantly better than MWFFT in Raman spectra standardization. The Raman spectra acquired with different spectrometers can be standardized by RS-VPdtw to search the same spectral library, which can avoid the time-consuming and labor-intensive reestablishment of spectral libraries for different spectrometers. This means that RS-VPdtw is a promising and valuable method to solve the spectra standardization problem in large-scale applications of Raman spectroscopy.

Axial chirality was induced by circularly polarized light to covalent organic frameworks as well as hyperbranched polymers composed of bezene-1,3,5-triyl core units and oligo(benzene-1,4-diyl) as linker units where variation in induction efficiency was rationally interpreted in terms of internal rotation dynamics studied through CPMAS C-13 NMR experiments including CODEX measurements.

Biomass waste recycling and utilization is of great significance for improving ecological environments and relieving the current energy crisis. Waste diatomite with an adsorbed mass of yeast protein resulting from beer filtration is feasibly converted into N-doped porous carbon (NPC) via high temperature thermal treatment. The resulting NPC inherits the three-dimensional hierarchical structure of the diatomite, with a unique rich-pore feature composed of micro/meso/macropores, which is beneficial for high exposure of the electrocatalytic sites and ion transfer and diffusion. The NPC compounds with controllable nitrogen doping are used for the oxygen reduction reaction (ORR) and in a supercapacitor. NPC-2 exhibits a half-wave potential of 0.801 V comparable to that (0.812 V) of commercially available Pt/C in alkaline media, along with a good methanol tolerance capacity and long-term stability for the ORR. Furthermore, as an electrode material, a symmetric supercapacitor based on NPC-2 manifests an outstanding specific capacitance of 151.5 F g−1 at a current density of 1 A g−1 and a considerable capacitance retention of 90.5% after a cycling performance test of 10 000 cycles. The NPC-2 based symmetric SC delivered an energy density of 13.47 W h kg−1 at a power density of 400 W kg−1. This work highlights the environmental significance of converting waste diatomite into metal-free ORR catalysts and electrode materials for energy conversion and storage technologies.

The cathode materials for sodium ion batteries (SIBs) are intrinsically unstable due to their oxidation by electrolyte solution at high voltage; thus, developing novel solid permeable interfaces as passivation layers is critical to avoid these side oxidation reactions and increase the cycling durability of SIBs. Nevertheless, the abuse of passivation layers can hinder the Na+ transfer and further impact the rate capability. Herein, we demonstrated an effective approach that utilized konjac glucomannan (KGM) biopolymer as a multifunctional binder to build stable solid permeable interface films to achieve high-performance for Na3V2(PO4)3/C (NVP) cathodes. Compared with polyvinylidene difluoride (PVDF), the strong adhesion and solid permeable interface films of KGM protect the integrity of the electrodes. The unique conductive network and rich polar functional groups enable KGM to enhance the transfer of electrons and Na+ ions at the interfaces. Thanks to the multiple functions of KGM offering adhesion strength, a conductive network and a solid permeable interface, the NVP cathode exhibited a reversible capacity of 108.0 mA h g−1 at 0.5C (1C = 117 mA g−1). At a high rate of 50C, NVP profited from KGM to show a good capacity of 63.1 mA h g−1 and a high durability of 10 000 cycles with a small fading rate of 0.00259% per cycle. Hard carbon‖NVP full batteries, using KGM as the cathode binder, possessed a high specific energy of 137.7 W h kg−1, indicating the potential applications of KGM as an environmentally friendly binder for achieving high-rate capacity and long-term cycling durability of SIBs.

SUMMARY Determining a detailed 3-D velocity model with high resolution for the sedimentary layer in the Sichuan Basin is potentially beneficial both to the industrial oil/gas exploration and earthquake hazards’ mitigation. In this study, we apply the ambient noise tomography method to construct a 3-D S-wave velocity model. This model focuses on the sedimentary layer of the Sichuan Basin, with a 0.3° × 0.3° grid precision. Dispersion curves of both group and phase velocities of Rayleigh wave at 4 to 40 s periods are utilized, which are extracted from 87 broad-band stations in the Sichuan Basin and the surrounding areas. The 3-D model reveals a thick sedimentary layer of the Sichuan Basin with S-wave velocity ranging from ∼2.0 to 3.4 km s−1. The sediment thickness in the margins of the Sichuan Basin is generally greater than the typical values of 6–10 km in the central areas due to surrounding orogenic activities, with a maximum depth of ∼13 km in the northwestern margin. Moreover, a prominent low S-wave velocity anomaly in the margins may be caused by the sediment accumulations from large-scale landslides and pronounced denudation of the surrounding orogenic belts. Major geologic units in the sedimentary layer are delineated in this study. The S-wave velocity values within each geologic unit and their bottom interfaces are obtained. Based on our model, we calculate synthetic ground motions for the 2013 Lushan earthquake and obtain the distribution of the peak ground acceleration from the earthquake epicentre to the western Sichuan Basin. The result clearly illustrates the basin amplification effect on the seismic waves.

In additive manufacturing (AM), numerous thermal cycles make stress relaxation a significant factor in affecting the material mechanical response. However, the traditional material constitutive model cannot describe repeated annealing behavior. Here, we propose an improved constitutive model based on a serial of stress relaxation experiments, which can descript the temperature and time-dependent stress relaxation behavior during AM. By using the proposed relaxation model, the prediction accuracy is significantly improved due to the recovery of inelastic strain during multilayer deposition. The results are validated by both in-situ and final distortion measurements. The influence mechanism of the relaxation behavior on material mechanical response is explained by the three-bar model in thermo-elastic-plastic theory. The relaxation behavior during the whole AM process is clarified. The stress behavior is found to have a limited effect when merely depositing several layers; nevertheless, it becomes a prominent impact when depositing multiple layers. The proposed model can enhance modeling accuracy both in AM and in multilayer welding.

Transition-metal selenides have emerged as promising anode materials for sodium ion batteries (SIBs). Nevertheless, they suffer from volume expansion, polyselenide dissolution, and sluggish kinetics, which lead to inadequate conversion reaction toward sodium and poor reversibility during the desodiation process. Therefore, the transition-metal selenides are far from long cycling stability, outstanding rate performance, and high initial Coulombic efficiency, which are the major challenges for practical application in SIBs. Here, an efficient anode material including an FeSe2 core and N-doped carbon shell with inner void space as well as high conductivity is developed for outstanding rate performance and long cycle life SIBs. In the ingeniously designed FeSe2@NC microrods, the N-doped carbon shell can facilitate mass transport/electron transfer, protect the FeSe2 core from the electrolyte, and accommodate volume variation of FeSe2 with the help of the inner void of the core. Thus, the FeSe2@NC microrods can maintain strong structural integrity upon long cycling and ensure a good reversible conversion reaction of FeSe2 during the discharge/charge process. As a result, the as-prepared FeSe2@NC microrods exhibit excellent sodium storage performance and ultrahigh stability, achieving an excellent rate capability (411 mAh g-1 at 10.0 A g-1) and a long-term cycle performance (401.3 mAh g-1 after 2000 cycles at 5.0 A g-1).

Thermoelectric materials enable the mutual energy conversion of waste heat and electricity, critical to relieve global energy crisis. Hightemperature thermoelectric materials are special species due to their high-temperature stability and noticeable energy conversion efficiency. Here, we report a systematic investigation on high-temperature thermoelectric gadolinium selenides, cubic Gd3-xSe4 (x = 0.16, 0.21 and 0.25) and orthorhombic Gd2Se3-y (y = 0.02, 0.06 and 0.08). High energy synchrotron x-ray diffraction and total scattering are used to investigate the crystallographic and local structures. The atomic-scale cluster of Gd vacancy in cubic Gd2.84Se4 is observed by employing the reverse Monte Carlo simulation. For cubic Gd3-xSe4, its carrier concentration is tuned and multiple conduction bands are incorporated by adjusting Gd vacancy. Experimentally, the gradual increase in effective masses is evidently observed in cubic Gd3-xSe4, which is consistent with the density functional theory (DFT) calculation. A reasonable peak zT value of 0.27 is achieved at 850 K for Gd2.84Se4. On the other hand, adjusting Se vacancy enables the optimization of electron concentration for orthorhombic Gd2Se3-y phase. Its low deformation potential (Ξ = 12eV) with single conduction band gives rise to enhanced electron mobility and higher peak zT value of 0.54 at 850 K for Gd2Se2.98. In addition, a higher zT of 1.2 at1200 K is reasonably predicted for Gd2Se2.98 by using quality factor analysis. This work not just presents a systematic crystallographic investigation of gadolinium selenides, but also provides a deep insight into the charge transport and phonon scattering mechanisms. This study facilitates the exploration of more high-temperature thermoelectric materials. Ministry of Education (MOE) Accepted version The authors would like to acknowledge EFRC Solid-State-Thermal Energy Conversion Center (S3TEC), Grant DE-SC000XXXX. This work is also supported by Japan Society for the Promotion of Science (JSPS) KAKENHI, Grant JP 19F19057. L. H. acknowledge the International Research Fellow of JSPS. Q. F. Y. acknowledge the Chinese Scholarship Council (CSC) for the scholarship in Tokyo Institute of Technology. A. Q. Yan acknowledges Singapore MOE Tier 2 under Grant MOE2018-T2-1- 010. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Science, under Contract No. DE-AC02-06CH11357.