Operando NMR methods for studying electrocatalysis

The combination of electrochemical measurements with spectroscopic characterizations provides valuable insights into reaction mechanisms.Nuclear magnetic resonance(NMR)spectroscopy,as a powerful technique due to its atomic specificity and versatility in studying gas,liquid,and solid,allows the study of electrolyte solution,catalyst and catalyst-adsorbate interfaces.When applied in operando,NMR can offer molecular-level insights into various electrochemical processes.Operando NMR has been applied extensively in battery research,but relatively underexplored for electrocatalysis in the past two decades.In this mini review,we first introduce the operando electrochemical NMR setups,categorized by different probe designs.Then we review the applications of operando NMR for monitoring the electrolyte solution and the catalyst-adsorbate interface.Considering the high environmental impact of electrochemical conversion of CO_(2)into value-added products,we zoom in to the use of operando NMR in studying electrochemical CO_(2)reduction.Finally,we provide our perspective on further developing and applying operando NMR methods for understanding the complex reaction network of Cu-catalyzed electrochemical CO_(2)reduction.

The Predicted fcc Superconducting Phase for Compressed Se and Te

In the framework of the ab initio random structure search method,we show that elemental Se and Te undergo pressure-induced structural transition from the bcc to fcc phase,in agreement with the theoretical results previously reported.By means of the pseudopotential plane-wave method based on density functional perturbation theory,the fcc structure for both elements is found to be another phonon-mediated superconducting phase of these materials.With a reasonable value for the Coulomb pseudopotentialμ^(*)=0.12,the maximum superconducting transition temperature Tc in the fcc phase of Se and Te is estimated to be about 5.7 K and 4.6 K,respectively.Furthermore,we show that in the entire fcc phase for Se and Te,the superconducting transition temperature decreases together with the increase in pressure,leading to the final suppression of the superconductivity.It is suggested that such behavior is mainly caused by the rapid increase in the mean-square phonon frequency(ω^(2))with pressure.Finally,a very strong electron-phonon coupling value,for both Se and Te in the fcc phase,is found along the G-K high symmetry lines.

Investigation of Li-ion transport in Li7P3S11 and solid-state lithium batteries

The high Li-ion conductivity of the Li7P3S11 sulfide-based solid electrolyte makes it a promising candidate for all-solid-state lithium batteries. The Li-ion transport over electrode-electrolyte and electrolyteelectrolyte interfaces, vital for the performance of solid-state batteries, is investigated by impedance spectroscopy and solid-state NMR experiments. An all-solid-state Li-ion battery is assembled with the Li7P3S11 electrolyte, nano-Li2S cathode and Li-In foil anode, showing a relatively large initial discharge capacity of 1139.5 m Ah/g at a current density of 0.064 m A/cm^ 2 retaining 850.0 m Ah/g after 30 cycles. Electrochemical impedance spectroscopy suggests that the decrease in capacity over cycling is due to the increased interfacial resistance between the electrode and the electrolyte. 1D exchange ^7Li NMR quantifies the interfacial Li-ion transport between the uncycled electrode and the electrolyte, resulting in a diffusion coefficient of 1.70(3) ×10^-14cm^2/s at 333 K and an energy barrier of 0.132 e V for the Li-ion transport between Li2S cathode and Li7P3S11 electrolyte. This indicates that the barrier for Li-ion transport over the electrode-electrolyte interface is small. However, the small diffusion coefficient for Li-ion diffusion between the Li2S and the Li7P3S11 suggests that these contact interfaces between electrode and electrolyte are relatively scarce, challenging the performance of these solid-state batteries.

Advances in micropatterning technology for mechanotransduction research

Micropatterning is a sophisticated technique that precisely manipulates the spatial distribution of cell adhesion proteins on various substrates across multiple scales.This precise control over adhesive regions facilitates the manipulation of architectures and physical constraints for single or multiple cells.Furthermore,it allows for an indepth analysis of how chemical and physical properties influence cellular functionality.In this comprehensive review,we explore the current understanding of the impact of geometrical confinement on cellular functions across various dimensions,emphasizing the benefits of micropatterning in addressing fundamental biological queries.We advocate that utilizing directed self-organization via physical confinement and morphogen gradients on micropatterned surfaces represents an innovative approach to generating functional tissue and controlling morphogenesis in vitro.Integrating this technique with cutting-edge technologies,micropatterning presents a significant potential to bridge a crucial knowledge gap in understanding core biological processes.

Correlating O-deficiency and luminescence property of Tb^(3+)þdoped SrO

Cubic rock salt can lower down or break the rare earth transition barrier through interstitial or vacancy defects owing to its great deformation and rotationflexibility.Here,we demonstrate that oxygen vacancies in SrO are induced by proper oxidization and atmosphere adjustment,resulting in defects with various depths and crystalfield distortion.The thermally assisted tunneling from defects to 5 D_(4) state and electronic population decrease on 5 D_(3) state of Tb^(3+)þare observed by the deformation of adjacent oxygen octahedral structure.Finally,the asprepared SrO:0.01 Tb^(3+)þphosphors,commercial BaMgAl10O17:Eu^(2+)þblue phosphor,and CaAlSiN3:Eu^(2+)þred phosphor are mixed and coated onto 280 nm deep-ultraviolet LED chip to assemble white light-emitting LED device.The LEDs show CCT of 3850 K,4136 K,and 4741 K,with color rendering index of 90.3,90.8,and 92.1,respectively.These insights will advance the fundamental knowledge of crystal engineering in cubic rock salt,and enable new ways to manipulate energy transfer and electronic transition via defects.

Electron correlation effects on exchange interactions and spin excitations in 2D van der Waals materials

Despite serious effort,the nature of the magnetic interactions and the role of electron-correlation effects in magnetic twodimensional(2D)van der Waals materials remains elusive.Using CrI3 as a model system,we show that the calculated electronic structure including nonlocal electron correlations yields spin excitations consistent with inelastic neutron-scattering measurements.Remarkably,this approach identifies an unreported correlation-enhanced interlayer super-superexchange,which rotates the magnon Dirac lines off,and introduces a gap along the high-symmetryΓ-K-M path.This discovery provides a different perspective on the gap-opening mechanism observed in CrI3,which was previously associated with spin–orbit coupling through the Dzyaloshinskii–Moriya interaction or Kitaev interaction.Our observation elucidates the critical role of electron correlations on the spin ordering and spin dynamics in magnetic van der Waals materials and demonstrates the necessity of explicit treatment of electron correlations in the broad family of 2D magnetic materials.

A Multiresponsive Transformation between Surfactant-Based Coacervates and Vesicles

Low-molecular weight surfactants have significant potential as building blocks for prebiotic organization.However,reports about surfactant-based coacervates as protocell models capable of reversible transformation are scarce.Herein,we develop a simple system made of a surfactant(-)-N-dodecylN-methylephedrinium bromide(DMEB)and inorganic salts that is capable of spontaneous formation of vesicles,coacervates,and the reversible transformation between the two states.

Target-activated and ratiometric photochromic probe for “double-check” detection of toxic thiols in live cells

Photochromic molecules can achieve reversible isomerization upon alternate light irradiations, which offers a great opportunity to improve the precision of analytes detection and imaging in complicated biological environments. Previous reported photochromic probe exhibited only mono-color switching and an initially fluorescence-ON state that may cause high background signal and impose an adverse impact on the desired sensing precision. To overcome this set-back, we developed a novel photochromic probe with an analyte-activation mode for ratiometric sensing of toxic thiols in both real water samples and live cells. The dynamic dual-fluorescence signal is released only after the fast and selective cleavage of the 2,4-dinitrophenyl sulfonate by the targeted thiophenol derivatives. Consequently, a "double-check" with synchronized dual-fluorescence blinking for analyte detection is successfully employed upon alternate light triggers with rapid response(k=7.2×10^(-2) s^(-1)), high sensitivity(LOD=6.1 nM) as well as selectivity of thiophenol derivatives over other common thiol species(e.g., GSH, Cys and Hcy). The photochromic probe was successfully introduced to the fast and on-site detection of highly toxic thiophenols in real waste water samples. Moreover, by using confocal laser-scanning microscopy(CLSM) and flow cytometric analysis, the potential applications of this ratiometric photochromic probe for trace toxic thiol sensing in live cells are examined.

NETosis,complement,and coagulation:a triangular relationship

NETosis is a regulated form of neutrophil cell death that contributes to the host defense against pathogens and was linked to various diseases soon after its first description in 2004.During NETosis,neutrophils release neutrophil extracellular traps(NETs),which can capture and kill bacteria and other pathogens to prevent them from spreading.Although substantial progress has been made in our understanding of NETosis,the precise mechanism underlying NETosis is still a matter of debate.Research continues to elucidate the molecular pathways involved in NETosis.In recent years,interactions with the complement and coagulation systems have become increasingly apparent.Activated complement proteins can stimulate NET formation,and NETs,in turn,can serve as a platform for complement activation.In addition,NETs can act as a scaffold for thrombus formation during coagulation.While crosstalk between the coagulation and complement systems has been previously described,NETosis appears to be a third important player in this consortium to protect the host against pathogens.This review summarizes our current knowledge on the mutual interactions between NETosis,the complement system and the coagulation system,with an emerging description of their complex triangular relationship.

Structure and Activity of Strigolactones： New Plant Hormones with a Rich Future

Strigolactones （SLs） constitute a new class of plant hormones which are active as germination stimulants for seeds of parasitic weeds of Striga, Orobanche, and Pelipanchi spp, in hyphal branching of arbuscular mycorrhizal （AM） fungi and as inhibitors of shoot branching. In this review, the focus is on molecular features of these SLs. The occurrence of SLs in root exudates of host plants is described. The naming protocol for SL according to the International Union of Pure and Applied Chemistry （IUPAC） rules and the ＇at a glance＇ method is explained. The total synthesis of some natural SLs is described with details for all eight stereoisomers of strigol. The problems encountered with assign- ing the correct structure of natural SLs are analyzed for orobanchol, alectrol, and solanacol. The structure-activity relationship of SLs as germination stimulants leads to the identification of the bioactiphore of SLs. Together with a tentative mechanism for the mode of action, a model has been derived that can be used to design and prepare active SL analogs. This working model has been used for the preparation of a series of new SL analogs such as Nijmegen-1, and analogs derived from simple ketones, keto enols, and saccharine. The serendipitous finding of SL mimics which are derived from the D-ring in SLs （appropriately substituted butenolides） is reported. For SL mimics, a mode of action is proposed as well. Recent new results support this proposal. The stability of SLs and SL analogs towards hydrolysis is described and some details of the mechanism of hydrolysis are discussed as well. The attempted isolation of the protein receptor for germination and the current status concerning the biosynthesis of natural SLs are briefly discussed. Some non-SLs as germinating agents are mentioned. The structure-activity relationship for SLs in hyphal branching of AM fungi and in repression of shoot branching is also analyzed. For each of the principle functions, a working model for the design of new active SL analogs is described and its applicability and implications are discussed. It is shown that the three principal functions use a distinct perception system. The importance of stereochemistry for bioactivity has been described for the various functions.

Dual-shot dynamics and ultimate frequency of all-optical magnetic recording on GdFeCo

Although photonics presents the fastest and most energy-efficient method of data transfer,magnetism still offers the cheapest and most natural way to store data.The ultrafast and energy-efficient optical control of magnetism is presently a missing technological link that prevents us from reaching the next evolution in information processing.The discovery of all-optical magnetization reversal in GdFeCo with the help of 100fs laser pulses has further aroused intense interest in this compelling problem.Although the applicability of this approach to high-speed data processing depends vitally on the maximum repetition rate of the switching,the latter remains virtually unknown.Here we experimentally unveil the ultimate frequency of repetitive all-optical magnetization reversal through time-resolved studies of the dual-shot magnetization dynamics in Gd27 Fe63.87 C09.T3.Varying the intensities of the shots and the shotto-shot separation,we reveal the conditions for ultrafast writing and the fastest possible restoration of magnetic bits.It is shown that although magnetic writing launched by the first shot is completed after 100 ps,a reliable rewriting of the bit by the second shot requires separating the shots by at least 300 ps.Using two shots partially overlapping in space and minimally separated by 300 ps,we demonstrate an approach for GHz magnetic writing that can be scaled down to sizes below the diffraction limit.

Strange metallicity and high-T_(c) superconductivity:quantifying the paradigm

A key goal of superconductivity research is to identify the mechanism by which electrons pair.Clues to the pairing mechanism lie in the resistive behavior(that is itself governed by electrons scattering off impurities and dynamical fluctuations within the material)above the superconducting transition temperature T_(c).

Environmental screening and ligand-field effects to magnetism in CrI_(3) monolayer

We study the microscopic origin of magnetism in suspended and dielectrically embedded CrI_(3)monolayer by down-folding minimal generalized Hubbard models from ab initio calculations using the constrained random phase approximation.These models are capable of describing the formation of localized magnetic moments in CrI_(3)and of reproducing electronic properties of direct ab initio calculations.Utilizing the magnet force theorem,we find a multi-orbital super-exchange mechanism as the origin of magnetism in CrI_(3)resulting from an interplay between ferro-and anti-ferromagnetic Cr-Cr d coupling channels,which is decisively affected by the ligand p orbitals.We show how environmental screening,such as resulting from encapsulation with hexagonal boron nitride,affects the Coulomb interaction in the film and how this controls its magnetic properties.Driven by a non-monotonic interplay between nearest and next-nearest neighbor exchange interactions we find the magnon dispersion and the Curie temperature to be non-trivially affected by the environmental screening.

Dodecagonal bilayer graphene quasicrystal and its approximants

Dodecagonal bilayer graphene quasicrystal has 12-fold rotational order but lacks translational symmetry which prevents the application of band theory.In this paper,we study the electronic and optical properties of graphene quasicrystal with large-scale tight-binding calculations involving more than ten million atoms.We propose a series of periodic approximants which reproduce accurately the properties of quasicrystal within a finite unit cell.By utilizing the band-unfolding method on the smallest approximant with only 2702 atoms,the effective band structure of graphene quasicrystal is derived.The features,such as the emergence of new Dirac points(especially the mirrored ones),the band gap at M point and the Fermi velocity are all in agreement with recent experiments.The properties of quasicrystal states are identified in the Landau level spectrum and optical excitations.Importantly,our results show that the lattice mismatch is the dominant factor determining the accuracy of layered approximants.The proposed approximants can be used directly for other layered materials in honeycomb lattice,and the design principles can be applied for any quasi-periodic incommensurate structures.

Medical micro-and nanomotors in the body

Attributed to the miniaturized body size and active mobility,micro-and nanomotors(MNMs)have demonstrated tremendous potential for medical applications.However,from bench to bedside,massive efforts are needed to address critical issues,such as cost-effective fabrication,on-demand integration of multiple functions,biocompatibility,biodegradability,controlled propulsion and in vivo navigation.Herein,we summarize the advances of biomedical MNMs reported in the past two decades,with particular emphasis on the design,fabrication,propulsion,navigation,and the abilities of biological barriers penetration,biosensing,diagnosis,minimally invasive surgery and targeted cargo delivery.Future perspectives and challenges are discussed as well.This review can lay the foundation for the future direction of medical MNMs,pushing one step forward on the road to achieving practical theranostics using MNMs.

Coexisting charge density wave and ferromagnetic instabilities in monolayer InSe

Recently fabricated InSe monolayers exhibit remarkable characteristics that indicate the potential of this material to host a number of many-body phenomena.In this work,we systematically describe collective electronic effects in hole-doped InSe monolayers using advanced many-body techniques.To this end,we derive a realistic electronic-structure model from first principles that takes into account the most important characteristics of this material,including a flat band with prominent van Hove singularities in the electronic spectrum,strong electron–phonon coupling,and weakly screened long-ranged Coulomb interactions.We calculate the temperature-dependent phase diagram as a function of band filling and observe that this system is in a regime with coexisting charge density wave and ferromagnetic instabilities that are driven by strong electronic Coulomb correlations.This regime can be achieved at realistic doping levels and high enough temperatures,and can be verified experimentally.We find that the electron–phonon interaction does not play a crucial role in these effects,effectively suppressing the local Coulomb interaction without changing the qualitative physical picture.

Magnetic skyrmions:Basic properties and potential applications

Magnetic skyrmions are particle-like topological magnetic textures that are potential information carriers in future spintronics.An enormous body of research confirms their existence in a broad range of magnetic materials since their first discovery in 2009.To date,magnetic skyrmions can not only be found in asymmetric systems but also in centrosymmetric ones.Notably,engineered magnetic multilayers are promising structures for skyrmion-based spintronics because they can stabilize small-sized skyrmions at room temperature and facilitate their electric manipulation.In this overview,we introduce the topological nature,their special properties,and nucleation methods of skyrmions,and show their potential for applications.Perspectives on skyrmionic devices and developments toward other,more three-dimensional particle-like magnetic nanostructures,are discussed at the end.

Common microscopic origin of the phase transitions in Ta_(2)NiS_(5) and the excitonic insulator candidate Ta_(2)NiSe_(5)

The structural phase transition in Ta-NiSes has been envisioned as driven by the formation of an excitonic insulating phase.However,the role of structural and electronic instabilities on crystal symmetry breaking has yet to be disentangled.Meanwhile,the phase transition in its complementary material Ta_(2)NiS_(5)does not show any experimental hints of an excitonic insulating phase.We present a microscopic investigation of the electronic and phononic effects involved in the structural phase transition in Ta_(2)NiSe_(5)and Ta-Niss using extensive first-principles calculations.In both materials the crystal symmetries are broken by phonon instabilities,which in tum lead to changes in the electronic bandstructure also observed in the experiment.A total energy landscape analysis shows no tendency towards a purely electronic instability and we find that a sizeable lattice distortion is needed to open a bandgap.We conclude that an excitonic instability is not needed to explain the phase transition in both Ta_(2)NiSe_(5)and Ta_(2)NiS_(5).

Resource optimisation in aquaponics facility via process monitoring and graph-theoretical approach

Energy efficiency and economic viability are the often-quoted issues in aquaponic farming.This work aims to(i)identify process technologies and technical measures which would enhance the profitability of aquaponics business while conserving energy and other resources,and(ii)to validate the determined optimal measures on the testing aquaponics farm.The process network synthesis technique was used to search for an optimal process pathway while the image processing technique was applied to automatically monitor the growth rate of produce since it is the main revenue stream in aquaponics.With the aid of P-graph method,the optimal feasible structure has 9 times higher annual net income than that of the existing process.This optimal solution includes the integration of electrical heat pump,biogas system,and utilizes black solider fly(BSF)facility to produce fish feed.Additional light energy savings were achieved by practical installation of reflective foils which improved 16.88%of Photosynthetic photon flux density(PPFD)on growth beds.These measures can help the aquaponics farms to become more competitive and to decrease their ecological footprint.

Universal orthoferrites and orthoferrites as a universe

It is hard to imagine,but such an exotic and little-known material as rare-earth orthoferrite can rightfully be called a source of inspiration for many generations of scientists in magnetism during the last 60 years.Orthoferrites host antiferromagnetism,the Dzyaloshinkskii–Moryia interaction,magnetoelectricity[1],multiferroicity[2],and bubble domains,which are often seen as a prototype of topologically protected spin textures.Orthoferrites are characterized by very strong magnetooptical[3]and magneto-acoustic effects[4],THz frequencies of spin resonances[5],and record high domain-wall velocities[6].Practically all of these phenomena and effects were once or still are a subject of intense research interest in magnetism,and rareearth orthoferrites can be seen as a universal playground material to discover and explore the hottest topics of modern magnetism.It is thus not surprising that also newly emerging fields chose orthoferrites as a model material.It was exactly the case in 2004,when the very first experiments on laser-induced spin dynamics in orthoferrites[7]revealed a plethora of opportunities for experimental research in,at that time,the young,but already rapidly developing field of ultrafast magnetism[8].The paper“THz spin dynamics in rare-earth orthoferrites”by X.Li et al.reviews nearly 20 years of history of ultrafast magnetism in orthoferrites.