Polymer composites with magneto-responsive performance attract extensive attention in soft robotics, flexible sensors, and biomedical devices. However, the severe agglomeration of magnetic nanoparticles (MNPs) in silicone rubber matrix remains a key obstacle to achieving high magnetic-mechanical conversion efficiency and reliable performance. To address this limitation, this study develops a microwave-assisted non-covalent functionalization strategy. Under thermal stimulation, the polydimethylsiloxane prepolymer spreads and physically adheres to the BaCoxTixFe12_ 2xO19 (BCTF nano-flakes) surface via non-covalent interactions (physical chain entanglement, hydrogen bonding, and hydrophobic forces), which significantly reduces filler agglomeration and strengthens interfacial adhesion. The synergistic effect of these non-covalent interactions enables the composite to achieve efficient magnetic-mechanical conversion efficiency. The optimized magneto-responsive elastomer (MRE) exhibits a maximum magnetorheological effect of 5.45% under 1000 mT (a 164.56% improvement compared to the unmodified composite), with tensile strength increased by 19.36% to 4.50 MPa. Although the elongation at break decreases from 339% to 220%, the retained flexibility is sufficient for soft actuator and flexible sensor applications. Additionally, the tans peak shifts to a higher temperature by 5.06 degrees C, confirming strengthened interfacial adhesion. These results demonstrate the potential of MREs fabricated via this modification method for applications in advanced soft actuators and flexible sensors.

With the development of the marine economy, flexible devices based on dielectric elastomers are increasingly considered for marine applications. However, the influence of high humidity, heat and intense UV radiation in such environments on the structure, mechanical properties and actuation performance of these materials remain poorly understood. In this study, a UV-humidity-heat multi-factor aging test platform was employed to simulate the aging process of barium strontium titanate/fluorosilicone rubber (BST/FSR) dielectric elastomer composites under high-humidity and high-temperature marine conditions. Through systematic analysis of microstructure, mechanical behavior and actuation performance of the materials, it was revealed that crosslinking reactions and molecular chain breakage occur simultaneously during aging, with molecular chain breakage dominating and inducing the decline in mechanical properties. This work comprehensively elucidates the aging behavior and mechanisms of fluorosilicone rubber-based dielectric elastomers in the high-humidity and heat environments, and establishes the interrelationships among dielectric, mechanical and actuation properties during the aging process. These findings further promote the application of dielectric elastomers in the marine environments and provide a theoretical basis for predicting the service life of their actuation performance.

Carbon aerogels are recognized as promising electromagnetic wave absorbers due to their lightweight nature, tunable conductivity, and structural versatility, but exhibit limited performance owing to impedance mismatch and narrow loss mechanisms. Here, a bimetallic synergistic strategy to fabricate a CoNi/C composite aerogel through metal-organic framework (MOF) derived self-assembly followed by pyrolysis. The introduced CoNi multiphase system not only optimizes magnetic loss via natural resonance, exchange resonance, and eddy current effects but also regulates the carbon matrix to enhance conductive networks and defect-induced polarization. The CoNi/C aerogel exhibits an impressive electromagnetic wave absorption performance of-53.12 dB at 2.7 mm and an effective absorption bandwidth of 8.32 GHz at 3.0 mm. Besides, the aerogel also demonstrates classy radar stealth performance. This work provides a strategy for developing lightweight, high-performance microwave absorbers through coordinated structural and electromagnetic regulation.

Magneto-responsive soft robots urgently demand high-performance magnetic fillers with high saturation magnetization, low coercivity, uniform particle size and dispersibility. In this work, CoTi co-doped M-type barium ferrite BaCoxTixFe12-2xO19 (BCTF) powders were successfully synthesized via a chemical co-precipitation combined with molten salt-assisted calcination. The influences of molten salt proportion and salt-to-precursor ratio on phase composition, microstructure, particle dimension and magnetic performances were systematically explored. The molten salt medium likely shifts the reaction away from sluggish solid-solid diffusion and implies a plausible dissolution-precipitation reaction pathway, effectively suppressing particle agglomeration and improving crystallization quality. Well-crystallized BCTF with regular hexagonal platelet morphology and narrow particle size distribution is obtained after process optimization. The optimized sample delivers a high saturation magnetization of 53.88 emu/g, much higher than 50.85 emu/g of the sample without molten salt, and possesses favorable low coercivity for magnetic actuation. This work provides a facile molten-salt route to fabricate high-performance ferrite powders with optimized magnetic parameters, which exhibit great potential as candidate fillers for magneto-responsive soft actuators in future composite investigations.

M-type hexagonal strontium ferrite (SrFe12O19, SrM) nano-powders require optimized magnetic properties for the applications of permanent magnets, magnetic recording media, and microwave devices. However, ion-doping strategies for enhancing saturation magnetization (Ms) and magnetocrystalline anisotropy field (Ha) remain underexplored. This study employed chemical coprecipitation plus molten salt method to modify SrM with Lanthanum (La) and cobalt (Co) co-doping. La site occupation varies with content x. At x = 0.05, La substituted Sr and Co occupied Fe sites. While x = 0.10, partial La migrated into Fe sites, modulating Fe and Co interactions. Moderate Co substitution at preferred Fe sites (4f1, 2a, 12k) activates La-Co correlation, distorting the Co 4f1 polyhedron. This enhances Co orbital moment via spin-orbit coupling, boosting uniaxial anisotropy. Optimal doping (x = 0.10, y = 0.20) improves both Ms and Ha compared to SrM. These findings demonstrate that correlated La-Co interactions via selective site occupancy provide a decoupled substitution strategy for optimizing hexagonal ferrites magnetic properties.

Improving catalytic activity for volatile organic compounds (VOCs) oxidation and enhancing water-tolerance stability remain challenging in practical applications. Herein, a composite catalyst integrating Pt/CoOx-NiOx mesoporous nanorods (MNRs) with a phenyltriethoxysilane (PhTES)-modified surface was fabricated via a facile route for toluene oxidation. The mesoporous nanorod architecture was instrumental in enhancing the specific surface area and the accessibility of active sites. The Co-Ni heterojunction formed a built-in electric field (BIEF) at the interface, facilitating charge transfer and boosting catalytic performance. The incorporation of Pt enhanced the catalyst's reducibility at low temperatures and thereby induced the formation of oxygen vacancies, which, in turn, facilitated the adsorption and activation of O2. Furthermore, the PhTES layer enhanced wet-condition activity and toluene adsorption. The optimized 1 wt% Pt/1.5CoOx-1.5NiOx MNRs catalyst achieved 100% toluene conversion (500 ppm) at 165 degrees C under 36,000 mL g-1 h-1 WHSV while maintaining activity under humid conditions after PhTES modification. The reaction mechanism, as identified by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), adheres to the Mars-van Krevelen (MVK) pathway. This finding was corroborated by density functional theory (DFT) calculations, which revealed that Pt doping facilitates the generation of oxygen vacancies and intensifies the BIEF, thus offering novel insights into the oxidation mechanism of VOCs. (sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(VOCs)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)Pt/CoOx-NiOx(sic)(sic)(sic)(sic)(sic)(MNRs)(sic)(sic)PhTES(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).MNR(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),Co-Ni(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(BIEF),(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).Pt(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)O2(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic),PhTES(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)1 wt% Pt/1.5CoOx-1.5NiOx MNRs(sic)(sic)(sic)(sic)(sic)(sic)(sic)36,000 mL g-1 h-1,(sic)(sic)(sic)(sic)(sic)500 ppm(sic)(sic)(sic)(sic),(sic)165 degrees C(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)PhTES(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)Mars-van Krevelen(MVK)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(DFT)(sic)(sic)(sic)(sic)Pt(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)BIEF,(sic)VOCs(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).

High magnetic anisotropic field of nano-magnetic materials is critical for miniaturization and integration of highfrequency magnetic devices. epsilon-Fe2O3 exhibits huge magneto-crystalline anisotropy, but modulating its magnetic properties remains challenging. Herein, rare earth-doped epsilon-Fe2O3 nano-magnets (epsilon-RexFe2-xO3 (Re=Nd, Gd, Sm, x = 0.02-0.10)) were synthesized via a reverse-micelle and sol-gel method to elucidate spin exchange coupling in modulating magneto-crystalline anisotropy. The partial substitution position of rare element in the epsilon-Fe2O3 crystal lattice was Fe3+ octahedral site. The results showed that Nd3+ doping yields the most significant enhancement in coercivity (Hc) and uniaxial magnetic anisotropy constant (Ku), attributed to its large orbital angular momentum (L = 6) and strong 4f-3d hybridization. In contrast, Gd3+ (L = 0) modulates anisotropy primarily through lattice distortion and antiferromagnetic coupling, while Sm3+ exhibits intermediate effects due to partial orbital quenching. The ferromagnetic resonance frequency of the doped samples can be tuned across a wide range, covering multiple millimeter wave bands, demonstrating the effective tunability of magnetic anisotropy. This work demonstrates that rare earth ion-doping effectively controls spin exchange coupling to achieve tunable magnetic anisotropy in epsilon-Fe2O3 nano-magnets, offering a viable strategy for designing millimeter wave absorbers.

With the increasing complexity of flexible sensor application scenarios, in order to achieve their use in electric and magnetic fields, this paper introduces a core-shell structure with Ni-doped cobalt ferrites as the magnetic core and barium titanate as the dielectric layer, filling it into a polymer matrix to prepare flexible magneto-dielectric elastomer composites. Taking advantages of this design, the targets including the establishment of multi-functionalization and the retention of fine mechanical properties have been simultaneously achieved. The synthesized elastomer composites exhibit fine flexibility and excellent magneto-electric response. An optimum magnetic-induced deformation angle achieves to 55 degrees under an external magnetic field of 8000 Oe, and a maximum electric-induced deformation approaches to about 8.29% under an applied electric field of 5 kV/mm. Besides that, with Ni-doping, the magnetization behaviors of composite fillings could be tuned, resulting a controllable magnetic field response of the synthesized magneto-dielectric rubber composites. This work provides a novel way to design multi-functionalized flexible composites, which is significant for exploring multi-mode flexible sensors.Highlights Magneto-dielectric elastomers were prepared with using core-shell filling. The elastomer composites exhibit fine magnetic and electric field response. The composites maintained good flexible mechanical properties.

Microwave heat treatment has been employed instead of conventional heat treatment to rapidly synthesize yttrium iron garnet (YIG) nano powders based on chemical co-precipitation technique. Pure phase YIG powders can be formed in a short time, only 2 min with microwave heating temperatures above 850oC. As the microwave heating time was 10 min, the average particle size increased from about 34 to 88 nm. Owing to the microwave activation, the surface magnetic disordered phase content decreased and the powders achieved a high saturation magnetization of 30 emu/g. Taking advantages of microwave heating, the nucleation of YIG is promoted, and owing to the activated diffusion and chemical reactions in the precursor powders, the uniform growth of YIG particles is established. All these make contributions to the rapid formation of high-quality YIG nano powders.

The employment of lanthanum (La) doping into barium hexa-ferrite (BaM) nano powders triggers the Fe(II)-Fe(III) electronic-hopping motions, and activates the surface activity for polyaniline (PANI) deposition polymerization. This makes contributions to tunable magnetic properties of BaM and its electric-electric correlations with PANI surface layers, resulting in the interfacial magneto-electric synergistic effect of the composites, which greatly improves the microwave adsorbing properties of BaM nano powders together. The synthesized La0.10Ba0.90Fe12O19/PANI composites exhibit an optimum high-efficiency microwave absorbing performance with a high reflection loss of -69.35dB at 9.84GHz when the thickness of 2.76mm and an effective bandwidth of 5.12GHz with a small thickness of 1.88mm. This technique provides a strategy to refine the properties of magnetic nano powders through interfacial perspective.

Amide compounds are widely present in drug molecules and natural products, which can be synthesized by acid-amine condensation. It is urgent to design new photocatalysts for achieving both nitroaromatic reduction and C-H oxidation to obtain raw materials, carboxylic acids, and aromatic amines. Herein, a novel isopolymolybdate-incorporated photoactive metal-organic framework, NiMo12-TPT, was constructed by combining the oxidation catalyst [Mo12O40]8-, Ni(II) cation, and photosensitive ligand 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT). In the structure, the superior electron storage capacity of [Mo12O40]8-, with its multiple metal centers containing d-electrons, is conducive to providing electrons for the reduction of nitrobenzenes. The donor-acceptor structure of the TPT facilitates the separation of intramolecular charges. Furthermore, the π···π interactions between the TPT molecules promote the transfer of electrons and enhance the performance of photocatalysis. Under illumination, NiMo12-TPT can activate the C-H bonds to generate carboxylic acids with excellent selectivity and simultaneously realize the multistep proton-coupled electron transfer (PCET) process for nitroaromatic reduction. Moreover, EPR tests and the quenching experiments indicated that •O2- is the main reactive oxygen species (ROS) in the photocatalytic redox reaction process.

Bi4Ti3O12 (BiTO) is a typical bismuth-layered Aurivillius ferroelectric material for its potential application in photocatalysis. In this study, Au/BiTO hybrid was fabricated by precipitating Au nanoparticles onto BiTO nanoflake using a sodium citrate reduction route. This integration has led to a remarkable enhancement in the photocatalytic efficiency of the composite, which is attributed to the synergistic coupling of piezoelectric effect with the localized surface plasmon resonance (LSPR) of Au nanoparticles. The incorporation of Au nanoparticles onto the BiTO matrix has significantly boosted the light absorption and charge carrier separation, thereby augmenting the photocatalytic activity. Notably, Au/BiTO-2 composite exhibits exceptional photocatalytic performance, demonstrating the complete degradation of RhB within 40 min under full-spectrum light irradiation. Moreover, Au/BiTO-2 displays a robust photocatalytic action against other organic pollutants, including methyl orange (MO), ofloxacin (OFLX) and tetracycline hydrochloride (TC). Further enhancement of photocatalytic process is achieved when combing light irradiation with ultrasonic excitation. The ultrasonic waves break the static spontaneous polarization through alternating piezoelectric potential, which accelerates the catalytic reaction. The photocatalytic action rate of Au/BiTO-2 toward RhB reaches a value as high as 0.0984 min-1, which is nearly 2.3 folds increasement compared to that of pristine BiTO. The possible synergistic mechanism caused by piezoelectric effect and exciton-plasmon effect is discussed in detail. The work not only enriches our understanding of the underlying principles but also supply a new strategy to design high-performance catalysts in the field of environmental remediation and energy conversion.

Magnetic elastomer composites are extending the field of soft robotics by integrating the flexibility of elastomers with the versatile performance of magnetic materials. In this work, a series of magnetic elastomers (BaCoxTixFe12-2xO19/PDMS) with tunable magnetic response have been successfully synthesized. In this composite, the magnetic component consists of Co-Ti co-doped barium hexaferrite (BaCoxTixFe12-2xO19, BCTF) nano powders, and the matrix is made of polydimethylsiloxane (PDMS). The coercivity (H-c) of BCTF can be reduced from 3950 Oe to 70 Oe, which bestow on the magnetic elastomer different magnetic response behavior. These magnetic elastomer composites obtained by blending have low Young's modulus, approximately 1.5 MPa. Furthermore, when applying the same external magnetic field, BaCo1.2Ti1.2Fe9.6O19/PDMS the magnetic deformation Angle can be as high as 60 degrees. These magnetic elastomers exhibit different magnetic-induced deformation owing to the adjustable permeability of the magnetic nanoparticles. This research significantly advances the design of applications with specific magnetic characteristics, such as sensors and transducers, thus opening new horizons for innovation in soft robotics and related fields.

A Fe3O4/Fe2O3 photoelectrode exhibiting excellent broadband and light-trapping characteristics has been pre-pared. It is found to be of unique multi-scale structure that is composed of pyramids from 5 to 10 mu m in width grown on nanorod arrays from 400 to 500 mu m in diameter. This multi-scale structure displays an extraordinary surface catalytic-activity and photothermal effect, which result in strong absorption in UV-Vis-NIR region and significantly improved PEC performance. Besides, type II p-n Fe2O3/Fe3O4 heterojunction with suitable energy position and its built-in electric field favor separation and transfer of photogenerated carriers. The optimized Fe2O3/Fe3O4 photoanode therefore exhibits a much larger photocurrent density-0.68 mA/cm2 at 1.23 V vs. RHE under simulated sunlight illumination compared to 0.08 mA/cm2 of the pure Fe2O3 photoelectrode. This unique design for multi-scale structure may provide a route to develop high-efficient photoelectrode with full -spectrum response.

As an emerging urban green infrastructure and continuous productive urban landscape, urban agriculture can increase the resilience of urban food systems and reduce carbon emission in food transportation. However, there are few studies in China on the potential of urban agriculture and its role in carbon emission reduction. With semantic segmentation and spatial analysis method to identify urban agricultural potential spaces on the ground and rooftops based on satellite images and Lidar point cloud data in the main urban area of Nanjing, we estimated their potential in vegetable production and the CO2 emission reduction effect in food transportation. The results showed that there were 2904.39 hm2 of ground and 2976.96 hm2 of rooftops in the study area with the potential to be used for urban agriculture. Under a scenario with 80% potential space utilization, it could produce approximately 225000 t of vegetables per year, which equated to 43.6% of annual vegetable consumption in the study area. Meanwhile, it would reduce CO2 emission in long distance food transportation by 63700 t per year.

为了实现液体降解反应中催化剂的简易回收,以碳纸为衬底,采用水热法将金红石相(rutile)TiO2 纳米棒负载在碳纸上,并利用不同浓度的双氧水(H2O2)对样品进行处理,得到不同氧空位浓度的 TiO2 样品.用 X 线衍射仪(XRD)和扫描电镜(SEM)对样品进行微结构表征,用 X线光电子能谱(XPS)和电子顺磁共振(EPR)测试分析样品中氧空位含量,发现随着双氧水浓度的增加,TiO2 样品中的氧空位含量增加.对样品进行紫外—可见漫反射光谱(UV-vis)测试,发现氧空位浓度增加能够有效提高样品的可见光吸收强度,结合光电化学(PEC)测试,分析氧空位对样品能带结构的影响.光催化降解 RhB染料实验表明,光催化效率随着氧空位浓度的增加而提升,在此基础上,利用超声协同光催化反应,能进一步提高光催化性能.

SnS2 with nanoflake-based microstructure and different concentrations of sulfur vacancy (SV) has been synthesized. The valence state of tin cation in the precursors is found to be closely related to the SV concentration in SnS2 nanoflake. SnS2 nanoflake with unsaturated tin cation in tin salt precursor (SnCl2·2H2O) favors to create SV. Sufficient SV is found to bring about a number of advantages such as smaller energy band gap, larger electrochemical active surface Area (ECSA), improved light absorption and separation efficiency of photogenerated charge carriers, which results in superior photocatalytic activities for degradation of RhB and CO2. SnS2 with more sulfur vacancies exhibits better photocatalytic activity for RhB degradation with a degradation rate 1.02×10−2min−1 and for CO2 reduction with an average CO production rate 2.44μmol∙g−1∙h−1. Above results not only reveal the importance of defect engineering, but also provide valuable guide to develop effective metal-sulfide photocatalysts for organic pollutant degradation and CO2 reduction.

The coordination environment of metal atoms in single-atom catalysts (SACs) has a greater impact on the catalytic performance of electrocatalysts. However, the influence mechanism of interacting ligands on the electrocatalytic nitrogen reduction reaction (NRR) process is still insufficient. Herein, by means of large-scale density functional theory (DFT) computations, the effect of organic ligands on the NRR process is investigated in-depth using half organometallic sandwich molecular SACs, i.e. TMBzs and TMCps (Bz = benzene, Cp = cyclopentadienyl, and TM = transition metal). The results revealed that the NRR performance of all the systems is highly dependent on the choice of d-pi interaction within the TM-Ligand complexes. Compared with TMBzs, the TMCps exhibit outstanding NRR activity and significantly suppress HER. Among 16 candidates, CrCp and MnBz are the most promising candidates with an ultra-low limiting potential of-0.29 V and-0.37 V via consecutive mechanism, respectively. Moreover, the systems with higher spin polarizations have better NRR activity. The work provides new insight into the NRR to molecular SACs with different organic ligands.

In the present work, TiO2 rutile nanorods and anatase nanoflakes have been grown on carbon fiber paper (CFP) by the hydrothermal method. Their photoelectrochemical properties and photocatalytic performances have been investigated. The introduction of CFP is found to improve visible light absorption intensity and effective surface areas apparently, and also make TiO2 photocatalysts easier to recycle from aqueous waste. An ultrasonic field was employed during the process of photocatalysis. Sono-photocatalytic efficiency is found to be enhanced significantly in comparison with those of photocatalysis and sonocatalysis, which indicates a positive ultrasonic synergy effect. The scavenger experiments reveal that superoxide radicals (˙O2-) and hydroxyl (˙OH) are the predominant active species during the dye degradation sono-photocatalytic process assisted by CFP-supported TiO2 catalysts. To investigate the ultrasonic synergy photocatalytic effect, the generated amount of reactive oxygen species (ROS) was detected and quantitatively evaluated under visible light, ultrasound, and the combined condition of visible light and ultrasound. As a result, the present work provides an efficient way to improve photocatalytic performance and to realize easy recovery of photocatalyst, which will be helpful for better design of advanced photocatalysts for practical applications.

Combining the ferroelectric/piezoelectric catalysts with photocatalysts was demonstrated as an effective way to facilitate the separation of photoinduced electrons and holes to superior synergistically catalytic activities. In this work, Bi4Ti3O12 (BiTO) nanoflowers were synthesized with Ag2O nanoparticles uniformly decorated on the surfaces, forming xAg(2)O/BiTO (x = 0-30%) hybrids. The light absorption, photocatalytic activity, and cyclic stability of BiTO nanoflowers were tremendously enhanced after Ag2O decoration. Density functional theory (DFT) calculations have confirmed the large ferroelectric spontaneous polarization along [100] axis in BiTO, which acts as built-in electric field to boost electrons and holes transfer into opposite direction. However, the static built-in electric field can easily be screened by free carriers. To resolve this item, ultrasonic excitation was introduced. The periodic mechanical vibration added on ferroelectrics could maintain the built-in field effective continuously, further improving the photocatalytic activity. Moreover, the ultrasonic frequency and electric poling were found to have influence on the photocatalytic activity. The poled 20%Ag2O/BiTO shows the optimum photocatalytic performance, and the underlying mechanisms were discussed in detail. (C) 2021 Elsevier B.V. All rights reserved.