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Abstract Kitaev interactions, arising from the interplay of frustration and bond anisotropy, can lead to strong quantum fluctuations and, in an ideal case, to a quantum-spin-liquid state. However, in many nonideal materials, spurious non-Kitaev interactions typically promote a zigzag antiferromagnetic order in the d-orbital transition-metal compounds. Here, by combining neutron scattering with muon-spin rotation and relaxation techniques, we provide mechanism insights into the exotic properties of Na2Co2TeO6, a candidate material of the Kitaev model. Below T N, the zero-field muon-spin relaxation rate becomes almost constant (~0.45 μs−1). We attribute this temperature-independent relaxation rate to the strong quantum fluctuations, as well as to the frustrated Kitaev interactions. As the magnetic field increases, neutron scattering data indicate a broader spin-wave excitation at the K-point. Therefore, quantum fluctuations seem not only robust but are even enhanced by the applied magnetic field. Our findings provide valuable hints for understanding the onset of the quantum-spin-liquid state in Kitaev materials.

In this research, Lactobacillus plantarum microcapsules were prepared by endogenous emulsification and microcapsule spheres were prepared by extrusion. The effects of four wall materials, which were sodium alginate, xanthan gum, gellan gum, and pectin, on the performance of Lactobacillus plantarum microcapsules were evaluated by determining the rate of encapsulation, the rate of survival after digestion in gastric fluids, and the effect of the dissolution of the bacteria in simulated gastrointestinal fluids. It was to improve the gastrointestinal fluid tolerance as well as release properties of Lactobacillus plantarum and to screen the wall materials suitable for the preparation of microcapsules hydrogel ball. The results showed that the microcapsule hydrogel ball prepared with sodium alginate as the wall material had the best effect. The particle size of the crystal ball was 3.30 mm. the water content was 93.99%. The structure was compact and the microstructure was good. The embedding rate of Lactobacillus plantarum was 87.14%, and the retention rate was 56.98% after 28 days, which remained at a high level. Simulated digestion in vitro showed that the survival rate of Lactobacillus plantarum after digestion in gastric juice was as high as 71.49%, and the release amount after intestinal digestion was 2.51×109 CFU/g. It demonstrated the good protective and slow-release capability of microcapsule hydrogel balls prepared with sodium alginate as wall material.

To evaluate the effects of different starter cultures and different fermentation substrates on the quality of fermented milk, the samples were prepared with Bifidobacterium animalis subsp. lactis (Ba) in co-cultures with traditional yogurt starter cultures (SL), and the acidification profile, viable bacteria count, water-holding capacity, proteolytic activity, rheological property, physical stability, microstructure, volatiles and sensory characteristic of fermented cow milk, fermented yak milk and fermented milk mixtures of cow to yak milk ratios of 1:1 were investigated. The results showed that for the same fermentation substrates, Ba-SL significantly improved the acidification property and viable bacteria count of fermented milk (P0.05). Ba-SL significantly enhanced the water-holding capacity of fermented cow milk and fermented mixed milk (P

The selection of proper reference genes is vital for ensuring precise quantitative real-time PCR (qPCR) assays. This study evaluates the stability of the expression of nine candidate reference genes in different tissues and during testicular development in H. labeo. The results show that eef1a is recommended as a reference gene for qPCR analysis in tissues and during testicular development. Furthermore, we evaluated the optimal number of reference genes needed when calculating gene expression levels using the geomean method, revealing that two reference genes are sufficient. Specifically, eef1a and rps27 are recommended for analysis of gene expression in tissues, whereas eef1a and actb are advised for evaluating gene expression during testicular development. In addition, we examined the expression pattern of kifc1, a kinesin involved in the reshaping of spermatids. We detected peak expression levels of kifc1 in testes, with its expression initially increasing before decreasing throughout testicular development. The highest expression of kifc1 was observed in stage IV testes, the active period of spermiogenesis, suggesting a possible role for kifc1 in the regulation of the reshaping of spermatids and hence testicular development. This study represents the first investigation of reference genes for H. labeo, providing a foundation for studying gene expression patterns and investigating gene expression regulation during testicular development.

Array pattern synthesis with low sidelobe levels is widely used in practice. An effective way to incorporate sensor patterns in the design procedure is to use numerical optimization methods. However, the dimension of the optimization variables is very high for large-scale arrays, leading to high computational complexity. Fortunately, sensor arrays used in practice usually have symmetric structures that can be utilized to accelerate the optimization algorithms. This paper studies a fast pattern synthesis method by using the symmetry of array geometry. In this method, the problem of amplitude weighting is formulated as a second-order cone programming (SOCP) problem, in which the dynamic range of the weighting coefficients can also be taken into account. Then, by utilizing the symmetric property of array geometry, the dimension of the optimization problem as well as the number of constraints can be reduced significantly. As a consequence, the computational efficiency is greatly improved. Numerical experiments show that, for a uniform rectangular array (URA) with 1024 sensors, the computational efficiency is improved by a factor of 158, while for a uniform hexagonal array (UHA) with 1261 sensors, the improvement factor is 284.

PurposeComparing the outcomes of video-laryngoscopy and flexible fiberoptic bronchoscopy for endotracheal intubation in patients with cervical spine immobilization.MethodsAll of the comparative studies published in the PubMed, Cochrane Library, Medline, Web of Science, and EMBASE databases as of 8 Jan 2024 were included. All outcomes were analyzed using Review Manager 5.4. The primary outcomes were the successful first-attempt intubation rate, intubation time, heart rate after intubation, mean arterial pressure after intubation, overall intubation success rate, risk of tissue damage and sore throat.ResultsThe meta-analysis included six randomized controlled studies with a total of 694 patients. The outcomes of the meta-analysis revealed that the use of video laryngoscopy was better than flexible fiberoptic bronchoscopy in terms of the successful first-attempt intubation rate (P0.05) between the video laryngoscopy and flexible fiberoptic bronchoscopy groups.ConclusionsCompared with flexible fiberoptic bronchoscopy, video laryngoscopy has superior tracheal intubation performance in terms of the first-attempt success rate and intubation speed. This finding was observed in patients with cervical spine immobilization who utilized a cervical collar to simulate a difficult airway. Additionally, both types of scopes demonstrated similar complication rates. Current evidence suggests that video laryngoscopy is better suited than flexible fiberoptic bronchoscopy for endotracheal intubation in patients immobilized with a cervical collar.Trial registrationSystematic review protocol: CRD42024499868.

Spin ice compounds are typically insulating and introducing carriers can destroy the spin ice state, making integration into electronic devices problematic. Here the authors report a transport response to an ice-rule-breaking transition in a heterostructure of a pyrochlore spin ice and a nonmagnetic metal.

Magnetic-field induced phase transitions in spin-ice materials have been investigated with various experimental techniques. Here, the authors demonstrate the capability of capacitive torque magnetometry in probing magnetic interaction energies and establishing magnetic phase boundaries in Ho2Ti2O7.

Abstract In partially ordered magnets, order and disorder coexist in the same magnetic phase, distinct from both spin liquids and spin solids. Here, we determine the nature of partial magnetic ordering in the canonical frustrated antiferromagnet Gd2Ti2O7, in which Gd3+ spins occupy a pyrochlore lattice. Using single-crystal neutron-diffraction measurements in applied magnetic field, magnetic symmetry analysis, inelastic neutron-scattering measurements, and spin-wave modeling, we show that its low-temperature magnetic structure involves two propagation vectors (2-k structure) with suppressed ordered magnetic moments and enhanced spin-wave fluctuations. Our experimental results are consistent with theoretical predictions of thermal fluctuation-driven order in Gd2Ti2O7, and reveal that inelastic neutron-scattering measurements on powder samples can solve the longstanding problem of distinguishing single-k and multi-k magnetic structures.

It remains difficult to identify non-trivial band topology through electronic transport in narrow-gap topological materials. Here, the authors demonstrate that an inverted band leads to a four-fold splitting of non-zero Landau levels and an anomalous zero Landau level peak in the density of states of ZrTe5, hence can serve as an indicator to explore non-trivial topology.

The honeycomb lattice with a spin-orbit interaction can give rise to exotic quantum states. With the measurements of bulk properties and inelastic neutron scattering, Lin et al demonstrate the existence of a field induced spin-disordered state in Na2Co2TeO6 and extend the Kitaev model to 3d system.

Developing an understanding of a material’s magnetic behaviour based on neutron scattering measurements often relies on extracting an effective spin model. Samarakoon et al. demonstrate an automated machine learning approach to this problem, leading to more robust inferences from complex data.

Abstract The manipulation of mesoscale domain wall phenomena has emerged as a powerful strategy for designing ferroelectric responses in functional devices, but its full potential is not yet realized in the field of magnetism. This work shows a direct connection between magnetic response functions in mechanically strained samples of Mn3O4 and MnV2O4 and stripe‐like patternings of the bulk magnetization which appear below known magnetostructural transitions. Building off previous magnetic force microscopy data, a small‐angle neutron scattering is used to show that these patterns represent distinctive magnetic phenomena which extend throughout the bulk of two separate materials, and further are controllable via applied magnetic field and mechanical stress. These results are unambiguously connected to the anomalously large magnetoelastic and magnetodielectric response functions reported for these materials, by performing susceptibility measurements on the same crystals and directly correlating local and macroscopic data.

We have performed combined elastic neutron diffuse, electrical transport, specific heat, and thermal conductivity measurements on the quasi–one-dimensional Ba3Co2O6(CO3)0.7 single crystal to characterize its transport properties. A modulated superstructure of polyatomic CO32− is formed, which not only interferes the electronic properties of this compound, but also reduces the thermal conductivity along the c-axis. Furthermore, a large magnetic entropy is observed to be contributed to the heat conduction. Our investigations reveal the influence of both structural and magnetic effects on its transport properties and suggest a theoretical improvement on the thermoelectric materials by building up superlattice with conducting ionic group.

The parametric spectro-temporal analyzer (PASTA) system has been demonstrated as a flexible tool in single-shot spectrum measurements, especially for ultrafast non repetitive phenomena with arbitrary waveforms. However, the highly nonlinear fiber (HNLF) based PASTA is subject to a limited spectral resolution across a limited observation bandwidth, because the inherent dispersion and dispersion slope of the HNLF restrict the temporal numerical aperture (NA) of the time lens of current PASTA systems. Therefore, in this work, we propose and experimentally demonstrate a PASTA based on a dispersion-engineered silicon waveguide with a much lower accumulated dispersion and slope to improve the temporal NA. Leveraging the short interaction length and dispersion-engineered waveguide, a broadband phase-matching condition can be obtained, and the limited converted pump bandwidth can be overcome by implementing the time lens on the silicon waveguide. Compared to the HNLF-based PASTA, the silicon waveguide improves the temporal NA by a factor of 2.5: a 2.5-nm bandwidth pump can theoretically achieve an ultrahigh optical resolution of 1.3 pm (limited to 20 pm because of the acquisition bandwidth limit) over a 21-nm observation bandwidth. Moreover, the silicon waveguide-based PASTA presents a new way to integrate the whole system because of the waveguide configuration, and is promising for real-time measurements, which has not been possible with most conventional optical spectrum analyzers.

The origin and nature of glassy dynamics presents one of the central enigmas of condensed-matter physics across a broad range of systems ranging from window glass to spin glasses. The spin-ice compound Dy_{2}Ti_{2}O_{7}, which is perhaps best known as hosting a three-dimensional Coulomb spin liquid with magnetically charged monopole excitations, also falls out of equilibrium at low temperature. How and why it does so remains an open question. Based on an analysis of low-temperature diffuse neutron-scattering experiments employing different cooling protocols alongside recent magnetic noise studies, combined with extensive numerical modeling, we argue that upon cooling, the spins freeze into what may be termed a “structural magnetic glass,” without an a priori need for chemical or structural disorder. Specifically, our model indicates the presence of frustration on two levels, first producing a near-degenerate constrained manifold inside which phase ordering kinetics is in turn frustrated. A remarkable feature is that monopoles act as sole annealers of the spin network and their pathways and history encode the development of glass dynamics, allowing the glass formation to be visualized. Our results suggest that spin ice Dy_{2}Ti_{2}O_{7} provides one prototype of magnetic glass formation specifically and a setting for the study of kinetically constrained systems more generally.

Rare-earth nickelates undergo a metal-to-insulator transition accompanied by the formation of ordered lattice distortions, but the role of the lattice in the metallic phase remains unclear. Here the authors provide evidence that the metal is a polaronic liquid that freezes into the insulating state.

The improper ferroelectric mechanism of YMnO3 has been difficult to observe directly but is important for understanding its other interesting properties such as multiferroicity. Bansal et al. use neutron scattering and ab initio calculations to show that phonons drive the transition, confirming earlier theories.

An indispensable step to understand collective magnetic phenomena in rare-earth compounds is the determination of spatially anisotropic single-ion properties resulting from spin-orbit coupling and crystal field (CF). The CF Hamiltonian has a discrete energy spectrum—accessible to spectroscopic probes such as neutron scattering—controlled by a number of independent parameters reflecting the point symmetry of the magnetic sites. Determining these parameters in low-symmetry systems is often challenging. Here, we describe a general method to analyze CF excitation spectra using adjustable effective point-charges. We benchmark our method to existing neutron-scattering measurements on pyrochlore rare-earth oxides and obtain a universal point-charge model that describes a large family of related materials. We adapt this model to the newly discovered tripod kagome magnets (R_{3}Mg_{2}Sb_{3}O_{14}, R = Tb, Ho, Er, Yb) for which we report broadband inelastic neutron-scattering spectra. Analysis of these data using adjustable point-charges yields the CF wave functions for each compound. From this, we calculate thermomagnetic properties that accurately reflect our measurements on powder samples and predict the effective gyromagnetic tensor for pseudospin degrees of freedom—a crucial step to understand the exotic collective properties of these kagome magnets at low temperature. We present further applications of our method to other tripod kagome materials and triangular rare-earth compounds RMgGaO_{4} (R =Yb, Tm). Overall, this study establishes a widely applicable methodology to predict CF and single-ion properties of rare-earth compounds based on interpretable and adjustable models of effective point charges.

A promising route to realize entangled magnetic states combines geometrical frustration with quantum-tunneling effects. Spin-ice materials are canonical examples of frustration, and Ising spins in a transverse magnetic field are the simplest many-body model of quantum tunneling. Here, we show that the tripod-kagome lattice material Ho_{3}Mg_{2}Sb_{3}O_{14} unites an icelike magnetic degeneracy with quantum-tunneling terms generated by an intrinsic splitting of the Ho^{3+} ground-state doublet, which is further coupled to a nuclear spin bath. Using neutron scattering and thermodynamic experiments, we observe a symmetry-breaking transition at T^{*}≈0.32 K to a remarkable state with three peculiarities: a concurrent recovery of magnetic entropy associated with the strongly coupled electronic and nuclear degrees of freedom; a fragmentation of the spin into periodic and icelike components; and persistent inelastic magnetic excitations down to T≈0.12 K. These observations deviate from expectations of classical spin fragmentation on a kagome lattice, but can be understood within a model of dipolar kagome ice under a homogeneous transverse magnetic field, which we survey with exact diagonalization on small clusters and mean-field calculations. In Ho_{3}Mg_{2}Sb_{3}O_{14}, hyperfine interactions dramatically alter the single-ion and collective properties, and suppress possible quantum correlations, rendering the fragmentation with predominantly single-ion quantum fluctuations. Our results highlight the crucial role played by hyperfine interactions in frustrated quantum magnets and motivate further investigations of the role of quantum fluctuations on partially ordered magnetic states.

We performed a systematic study of the temperature- and field-dependence of magnetization and resistivity of Gd _2 PdSi _3 , which is a centrosymmetric skyrmion crystal. We show that a phase diagram can be constructed based on the anomalous magnetoresistance with one-to-one correspondence among all the feature, while the DC magnetization behavior is consistent with the reported phase diagram based on AC susceptibility. In addition, the crossover boundary from a paramagnetic state into the field-induced ferromagnetic state is also identified. Our results suggest that the ferromagnetic spin fluctuations above the Néel temperature play a key role in the high sensitivity of the resistivity anomalies to magnetic field, pointing to the rich interplay of different magnetic correlations at zero and finite wave vectors underlying the skyrmion lattice in this frustrated itinerant magnet.

The pyrochlore structure (A2B2O7) has been an object of consistent study by materials scientists largely due to the stability of the cubic lattice with respect to a wide variety of chemical species on the A or B sites. The criterion for stability under ambient conditions is controlled by the ratio of these cations, which is empirically 1.36 < RA/RB < 1.71. However, under applied pressure synthesis conditions, the pyrochlore lattice is stable up to RA/RB ∼ 2.30, opening up possibilities for new compounds. In this review, we will highlight recent work in exploring new rare-earth pyrochlores such as the germanates RE2Ge2O7 and platinates RE2Pt2O7. We highlight recent discoveries made in these pyrochlores such as highly correlated spin ice behavior, spin liquid ground states, and exotic magnetic ordering.

The spin-1/2 triangular lattice antiferromagnet YbMgGaO_{4} has attracted attention recently as a quantum spin-liquid candidate with the possible presence of off-diagonal anisotropic exchange interactions induced by spin-orbit coupling. Whether a quantum spin liquid is stabilized or not depends on the interplay of various exchange interactions with chemical disorder that is inherent to the layered structure of the compound. We combine time-domain terahertz spectroscopy and inelastic neutron scattering measurements in the field-polarized state of YbMgGaO_{4} to obtain better insight of its exchange interactions. Terahertz spectroscopy in this fashion functions as a high-field electron spin resonance and probes the spin-wave excitations at the Brillouin zone center, ideally complementing neutron scattering. A global spin-wave fit to all our spectroscopic data at fields over 4 T, informed by the analysis of the terahertz spectroscopy linewidths, yields constraints on the disorder-averaged g factors and exchange interactions. Our results paint YbMgGaO_{4} as an easy-plane XXZ antiferromagnet with the combined and necessary presence of subleading next-nearest neighbor and weak anisotropic off-diagonal nearest-neighbor interactions. Moreover, the obtained g factors are substantially different from previous reports. This work establishes the hierarchy of exchange interactions in YbMgGaO_{4} from high-field data alone and thus strongly constrains possible mechanisms responsible for the observed spin-liquid phenomenology.

We report the magnetic phase diagram of EuTi1−xBxO3 (B = Zr, Nb), determined from magnetization and heat capacity measurements. Upon Zr-doping, the antiferromagnetic ordering temperature TN of EuTi1−xZrxO3 gradually decreases from 5.6 K (x = 0) to 4.1 K (x = 1). Whereas a similar decrease in TN is observed for small amounts of Nb doping (x ≤ 0.05), ferromagnetism is induced in EuTi1−xNbxO3 with x > 0.05. The ferromagnetic interaction between localized Eu 4f spins mediated by itinerant electrons introduced by Nb doping results in the ferromagnetism in EuTi1−xNbxO3.

With the increasing impact of antibiotics on the environment, membrane separation technology has been widely used to treat antibiotics in water environment. The poor hydrophilicity of polyvinylidene fluoride (PVDF) membrane leads to the problems of low water flux and easy surface pollution during membrane separation. In this study, the surface of PVDF base film was modified by polyethyleneimine (PEI). The influence of modified membrane on the retention capacity, anti-fouling property and operation characteristics of sulfamethoxazole (SMX) and tetracycline (TC) was investigated. The effect of PEI concentration on the comprehensive performance of pure water flux and antibiotic rejection was investigated by changing the molecular weight of PEI. The results showed that the comprehensive performance was relatively best when the molecular weight of PEI was 10,000 Da (P-10K). It could remove 57.5% and 30% of SMX and TC from the simulated water samples, and 88.2% and 62.4% of SMX and TC from the actual river water samples. However, it is also accompanied by a large degree of membrane fouling, resulting in a decrease in membrane separation performance. After the rotation test of single factor variables, it was found that the cation strength and humic acid concentration had the greatest influence on the flux and antibiotic retention of the modified membrane through the steric hindrance effect. In the anti-fouling performance test, the membrane flux can be restored to 85% and 92.3% of the initial flux after acid washing and alkali washing, indicating that the anti-fouling performance of the PVDF membrane after surface cross-linking modification is improved. [ABSTRACT FROM AUTHOR]