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Owing to the unique electronic structure, kagome materials AV3Sb5 (A=K, Rb, Cs) provide a fertile platform of quantum phenomena such as the strongly correlated state and topological Dirac band. It is well known that RbV3Sb5 exhibits a 2×2 unconventional charge density wave (CDW) state at low temperature, and the mechanism is controversial. Here, by using scanning tunneling microscopy/spectroscopy (STM/STS), we successfully manipulated the CDW state in the Sb plane of RbV3Sb5, and realized a new √ 3×√ 3 modulation together with the ubiquitous 2×2 period in the CDW state of RbV3Sb5. The work provides a new understanding of the collective quantum ground states in the kagome materials.

The van der Waals (vdW) MnSb4Te7 is a newly synthesized antiferromagnetic (AFM) topological insulator hosting robust axion insulator state irrelative of the specific spin structure. However, the intrinsic hole doped character of MnSb4Te7makes the Fermi level far away from the Dirac point of about 180 meV, which is unfavorable for the exploration of exotic topological properties such as the quantum anomalous Hall effect (QAHE). To shift up the Fermi level close to the Dirac point, the strategy by partially replacing Sb by Bi as Mn(Sb1-x Bi x )4Te7 was tried and the magnetotransport properties, in particularly, the anomalous Hall effect, were measured and analyzed. Through the electron doping, the anomalous Hall conductance σ AHchanges from negative to positive between x = 0.3 and 0.5, indicative of a possible topological transition. Besides, a charge neutrality point (CNP) also appears between x = 0.6 and 0.7. The results would be instructive for further understanding the interplay between nontrivial topological states and the magnetism, as well as for the exploration of exotic topological properties.

The topological electronic structure plays a central role in the non-trivial physical properties in topological quantum materials. A minimal, hydrogen-atom-like topological electronic structure is desired for researches. In this work, we demonstrate an effort towards the realization of such a system in the intrinsic magnetic topological insulator MnBi2Te4, by manipulating the topological surface state (TSS) via surface modification. Using high resolution laser- and synchrotron-based angle-resolved photoemission spectroscopy (ARPES), we found the TSS in MnBi2Te4 is heavily hybridized with a trivial Rashba-type surface state (RSS), which could be efficiently removed by the in situ surface potassium (K) dosing. By employing multiple experimental methods to characterize K dosed surface, we attribute such a modification to the electrochemical reactions of K clusters on the surface. Our work not only gives a clear band assignment in MnBi2Te4, but also provides possible new routes in accentuating the topological behavior in the magnetic topological quantum materials.

Receptor downregulation is instrumental for many therapeutic interventions. Receptor knockout through gene-editing technologies is efficient but can introduce off-target mutations and chromothripsis. Regulation of gene expression at the protein level is a promising alternative. Here, we present results showing the targeted T cell antigen receptor (TCR) degradation using chimeric E3 fusion proteins that we call Receptor Targeting Chimeras (ReceptorTAC). We show that TCR degradation is dependent on enzymatically active, membrane-anchored E3 ligase variants. TCR specificity was achieved by direct fusion of an E3 domain to the CD3ζ transmembrane sequence. Jurkat and primary T cells stably expressing the ReceptorTAC constructs showed significantly reduced responses to TCR stimulation. We also used our ReceptorTAC technology to generate TCR-deficient, claudin18.2-specific CAR T cells, where the activity of the CAR was unaffected by the expression of the ReceptorTAC. These data indicate that our ReceptorTAC molecule can be used to generate allogeneic CAR T cells.

The magnetic and electrical transport properties of the two-dimensional ferromagnetic Fe3GeTe2 have proven to be a subject of intrigue, with a broad range of Curie temperatures (Tc) observed in recent studies, ranging from 160 K to 230 K, and even reaching room temperature by ionic gating. Despite these discoveries, the underlying mechanism behind the varying Tc values remains a puzzle. Here, we employed scanning transmission electron microscopy to explore the atomic structure of Fe3GeTe2 crystals exhibiting Tc values of 160, 210, and 230 K. The results of the elemental mapping reveal that Fe intercalation on the interstitial sites within the van der Waals gap is present in the high- Tc (210 and 230 K) samples. The electrical transport measurements demonstrate the presence of an exchange bias effect in these high- Tc samples, owing to the existence of ferromagnetic and antiferromagnetic interfaces, while this effect is absent in the low-Tc (160 K) samples. First-principles calculations further suggest that the Fe-intercalation layer may be responsible for the local antiferromagnetic coupling that gives rise to the exchange bias effect, and that the introduction of interlayer exchange paths greatly contributes to the enhancement of Tc. This discovery of the Fe-intercalation layer elucidates the mechanism behind the hidden antiferromagnetic ordering that underlies the enhancement of Tc in Fe3GeTe2.

In this paper, the finite-time stability (FTS) of singular switched systems that have time-varying delays and perturbations is investigated. First, the concept of the FTS of time-varying delay singular switched systems is given, and a specific event-triggered mechanism is proposed. Then, a state feedback mechanism is proposed based on the event-triggered mechanism. Second, using the L-K function and state space decomposition, adequate criteria for the FTS of singular switched systems are found. Sufficient requirements are also presented for meeting the finite-time stable $ H_\infty $ performance index $ \gamma $.

Interval-valued intuitionistic fuzzy set (IVIFS) is a flexible method to deal with uncertainty and fuzziness. For the past few years, extensive researches about the multi-attribute group decision making (MAGDM) problems based on IVIFSs has been extensively studied in many fields. In this study, the Taxonomy method based on IVIFSs (IVIF-Taxonomy) was proposed for MAGDM problems. For the sake of the objectivity of attribute weight, entropy is introduced into the proposed model. The IVIF-Taxonomy method fully considers the weight of the decision makers (DMs) and the homogeneity of the chosen alternatives, making it more realistic. In addition, we apply IVIF-Taxonomy method to fund selection to verify the validity of IVIF-Taxonomy method. Finally, the trustworthy of IVIF-Taxonomy method is proved by comparing with the aggregate operator, IVIF-TOPSIS method, IVIF-GRA method and modified IVIF-WASPAS method.

The pure Ca9Co12O28 thermoelectric (TE) material powder is synthesized by solid state sintering method. The powder is pressed into compact tablets under pressure of 200 MPa, 2.0 GPa, 2.5 GPa, 3.0 GPa, 3.5 GPa and 4.0 GPa, respectively. The electrical conductivity, Seebeck coefficient, thermal conductivity and hardness are tested. The properties of specimens under different high pressures are compared and analyzed. It is found that the relative density of the specimens under different high pressures can reach 95% approximately. The highest power factor of the specimens is 2.171μW/(cm·K2) at 3.5 GPa, which is 2.4 times that at 200 MPa. At the same time, the maximum Vickers hardness of the specimens under 3.5 GPa is 127.7 MPa, while that under 200 MPa is only 16.8 MPa, indicating that the hardness under 3.5Gpa is increased by about 6.6 times. More importantly, it is found that the thermal conductivity of the specimens decreases with pressure in the range of 2.5Gpa–4.0Gpa, which proves that high pressure can refine the heat transfer performance effectively. This study lays the foundation for the synthesis of new-type Ca9Co12O28 TE materials with high machinability, high power factor, low thermal conductivity and high TE figure of merit with high-pressure technology.

The degeneration of solitary wave solutions and interaction solutions between lumps and solitons are primarily explored for the (2+1)-dimensional KdV equation. Firstly, in accordance with the Hirota bilinear form, solitary wave solutions and periodic solitary wave solutions are derived through some new test functions. Then through the parameter limit approach, the lump solutions are gained by degeneration of solitary solutons. Secondly, the interaction solutions between lumps and solitons are given by using of the partial degeneracy of the $N$-soliton solutions. Finally, according to a different test function, some new singular periodic solitary waves solutions are derived via the extended homoclinic test method.

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With the progress of the times, decision-making problems have become increasingly complex. Under such circumstances, the problems of multiple attribute decision making have emerged. Based on the original MABAC method and its related applications, we propose to apply the MABAC method combined Cumulative Prospect Theory (CPT) with2-tuple linguistic Pythagorean fuzzy numbers (2TLPFNs). In the first place, we show a lot of definitions of Pythagorean fuzzy sets, 2-tuple linguistic Pythagorean fuzzy sets, the 2TLPFWA and 2TLPFWG operators. Next, illustrating calculation formulas according to the score function, the accuracy function and the basic operations of two 2TLPFNs. Afterwards, we simply explain the original MABAC method and the MABAC method with 2TLPFNs (2TLPFN-MABAC) based on the research of other scholars. Besides, we completely give the actual operations of the new method about MABAC method based on CPT for MAGDM with 2TLPFSs (2TLPFN-CPT-MABAC). In the end, by a case study of the assessment of houses, according to the proposed new method and making some comparative analyses among the new method and other methods. In a word, all above are for verifying the effectiveness. In view of the new method with the advantages, MADM problems can be better solved and the new method can be applied to more fields.

Analogous to black phosphorus, SnS processes folded structure that shows a strongly anisotropic optical absorption. Herein, by using ultrafast two-color pump and probe spectroscopy, the azimuthal angle dependence of nonlinear optical anisotropy in SnS is investigated. After 390 nm photoexcitation, the reflectivity of the 780 nm probe beam is first reduced significantly, followed by a complex alternation with the rotation of the sample along the

The lump solutions and interaction solutions are mainly investigated for the (2 + 1)-dimensional KPI equation. According to relations of the undetermined parameters of the test functions, the N-soliton solutions are showed by computations of the Maple using the Hirota bilinear form for (2 + 1)-dimensional KPI equation. One type of the lump solutions for (2 + 1)-dimensional KPI equation has been deduced by the limit method of the N-soliton solutions. In addition, the interaction solutions between the lump and N-soliton solutions of it are studied by the undetermined interaction functions. The sufficient conditions for the existence of the interaction solutions are obtained. Furthermore, the new breather solutions for the (2 + 1)-dimensional KPI equation are considered by the homoclinic test method via new test functions including more parameters than common test functions.

The paper composite sandwich structure with corrugation and honeycomb cores has been widely used in civil and national defense industries, and the cushioning energy absorption characteristic is a key indicator to evaluate the performance of this composite structure. Therefore, this paper is focused on the influences of honeycomb thickness on the shock acceleration response and deformation characteristics to analyze cushioning energy absorption performance of the composite structure by various experimental tests. The experimental result shows that the paper corrugation layer firstly comes into crushed, and then the paper honeycomb layer is crushed. Additionally, the large honeycomb thickness may cause the secondary collapse of paper honeycomb layer. Under the same impact energy or impact mass, the cushioning energy absorption of the single-sided composite sandwich structure is better than that of the double-sided structure with the same honeycomb thickness. However, the impact resistance of the double-sided composite structure is better than that of the single-sided structure. For the paper composite sandwich structures with the honeycomb thicknesses 10, 15, 20, and 25 mm, the increase of honeycomb thickness would decrease the cushioning energy absorption of the whole structure under the drop impact with low energy. However, under the drop impact with high energy, the influence of honeycomb thickness on cushioning energy absorption is contrary. For the paper composite sandwich structure, the specific energy absorption, unit volume energy absorption, and stroke efficiency for the honeycomb thicknesses 10, 15, 20, and 25 mm are higher than those for the honeycomb thickness 70 mm. Therefore, the low honeycomb thickness is more advantageous for the cushioning energy absorption of paper composite sandwich structure.

Intrinsic ferromagnetic superlattice with nontrivial topological properties is a fertile ground to explore extoic quantum properties, such as the quantum anomalous Hall effect, large tunneling magnetoresistance, etc., which would have potential applications in next-generation spintronic devices. In this work, combining magneto-transport measurements, first principles calculations, and angle-resolved photoemission spectroscopy studies, we find that in a newly synthesized natural van der Waals MnSb2Te4/(Sb2Te3)2 superlattice, the competing magnetic interactions give rise to a fragile ferromagnetic ground state, which whereas very easily enters into the antiferromagnetic states at higher temperatures. Moreover, the system can be forced in to a ferromagnetic state by very small vertical magnetic field. Interestingly, MnSb2Te4/(Sb2Te3)2 would stay in axion insulator states for both ferromagnetic and antiferromagnetic configurations, which are protected by inversion-symmetry and the combination of time-reversal and half lattice translation symmetries, respectively. The axion insulator state can be converted into a Weyl semimetal with hole doping, manifested by the notable intrinsic anomalous Hall effect. Our work thus provides an intrinsic ferromagnetic topological material which can be tuned into versatile topological phases by temperature, magnetic field, as well as carrier doping.

Magnetic domain formation in two-dimensional (2D) materials gives perspectives into the fundamental origins of 2D magnetism and also motivates the development of advanced spintronics devices. However, the characterization of magnetic domains in atomically thin van der Waals (vdW) flakes remains challenging. Here, we employ X-ray photoemission electron microscopy (XPEEM) to perform layer-resolved imaging of the domain structures in the itinerant vdW ferromagnet Fe

The study of magnetic order in few- and monolayer van der Waals materials poses a challenge to the most commonly employed magnetic characterization techniques as they normally lack magnetic sensitivity and/or lateral resolution enabling their thickness-dependent probing. Here we demonstrate the usefulness of x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) measurements, carried out at the Cr L 2 , 3 and Te M 5 edges, for the study of the ferromagnetic semiconductor CrSiTe3 (CST) in the form of single- and few-layer flakes. By scanning the sample under the incident x-ray beam, a map of the exfoliated system was obtained, which reproduced the optical micrographs showing the detailed distribution and thicknesses of the flakes. In this way, XAS/XMCD was performed at selected sample areas, revealing the thickness-resolved spectroscopic and magnetic properties of the flakes, such as the spin and orbital magnetic moments. The spin moment, in line with the saturation field, is decreasing with film thickness, revealing a single-domain and out-of-plane magnetization for the thinnest films. For CST, the electronic properties are governed by the strong covalent bond between the Cr 3d(e g ) and Te 5p states, giving rise to a superexchange scenario. We observed a gradually increasing ratio of orbital to spin moment for thinner flakes, which could be due to a further increase of the covalent mixing. Hysteresis loops were recorded at the Cr L 3 edge, showing an open loop for 10 down to ∼3 layers, while the bulk shows a wasp-waist shaped loop. With the transition temperature from the soft to the hard ferromagnetic state decreasing with thickness, the monolayer shows a narrowed, closed loop at 10 K, suggesting its transition temperature > 10 K. Our study demonstrates the unique capabilities of XAS/XMCD for the study of few-layer van der Waals magnets, highlighting the interplay between electron correlation and ferromagnetism in CST.

In today’s world, environmental problems are becoming increasingly serious, and countries and regions are attaching great importance to them. Low-carbon and circular economy have become a strategic choice for China’s sustainable economic development. As the public’s awareness of environmental protection becomes stronger and stronger, the managers of companies ought to consider the maximum economic benefits. Meanwhile, they are supposed to focus on the green image of enterprises, so as to win in the market competition. The probabilistic linguistic term sets (PLTSs) are useful for expressing uncertain and fuzzy cognitions of the DMs over attributes. In this paper, we extend the Evaluation based on Distance from Average Solution (EDAS) method to the multiple attribute group decision making (MAGDM) with PLTSs. Firstly, concept, comparative formula, and distances of PLTSs are introduced in a nutshell. Then, the extended EDAS method is used to cope with the problems of MAGDM in PLTSs. In addition, for the sake of verifying the applicability of the expanding method, a calculation example about the sorting of green supplier is utilized. Consequently, the example shows that the method is easy to understand and operate. This method can be employed to choose the appropriate solution in other problems of selecting.

This study introduces the opinion of the corrugation hierarchy to develop the second-order corrugation paperboard, and explore the deformation characteristics, yield strength, and energy absorbing capacity under out-of-plane static evenly compression loading by experimental and analytical approaches. On the basis of the inclined-straight strut elements of corrugation unit and plastic hinge lines, the yield and crushing strengths of corrugation unit were analyzed. This study shows that as the compressive stress increases, the second-order corrugation core layer is firstly crushed, and the first-order corrugation structures gradually compacted until the failure of entire structure. The corrugation type has an obvious influence on the yield strength of the corrugation sandwich panel, and the yield strength of B-flute corrugation sandwich panel is wholly higher than that of the C-flute structure. At the same compression rate, the flute type has a significant impact on energy absorption, and the C-flute second-order corrugation sandwich panel has better bearing capacity than the B-flute structure. The second-order corrugation sandwich panel has a better bearing capacity than the first-order structure. The static compression rate has little effect on the yield strength and deformation mode. However, with the increase of the static compression rate, the corrugation sandwich panel has a better cushioning energy absorption and material utilization rate.

Two-dimensional materials with tunable in-plane anisotropic infrared response promise versatile applications in polarized photodetectors and field-effect transistors. Black phosphorus is a prominent example. However, it suffers from poor ambient stability. Here, we report the strain-tunable anisotropic infrared response of a layered material Nb

The ternary van der Waals material Nb2Six-1Te4 demonstrates many interesting properties as the content of Si is changed, ranging from metallic Nb3SiTe6 (x = 5/3) to narrow-gap semiconductor Nb2SiTe4 (x = 2) and with the emergence of one-dimensional Dirac fermion excitations in between. An in-depth understanding of their properties with different stoichiometry is important. Here we use scanning tunneling microscopy and spectroscopy to reveal that Nb2Six-1Te4 is a system with spontaneously developed and self-aligned one-dimensional metallic chains embedded in a two-dimensional semiconductor. Electron quasiparticles form one- and two-dimensional standing waves side by side. This special microscopic structure results in strong transport anisotropy. Along the chain direction the material behaves like a metal, while perpendicular to the chain direction, it behaves like a semiconductor. These findings provide an important basis for further investigation of this intriguing system.

The location of the electric vehicle charging station is deemed to be a multiple attribute group decision making (MAGDM) issue involving many experts and many conflicting attributes. In practical MAGDM issues, the information of uncertain and fuzzy cognitive decision is well-depicted by linguistic term sets (LTSs). These LTSs could be simply shifted into the probabilistic linguistic sets (PLTSs). In such paper, we design some novel probabilistic linguistic weighted Dice similarity measures (PLWDSM) and the probabilistic linguistic weighted generalized Dice similarity measures (PLWGDSM). Subsequently, the PLWGDSM-based MAGDM methods are presented under PLTSs. In the end, a practical case which concerns about the location planning of electric vehicle charging stations is offered to demonstrate the proposed PLWGDSM’s applicability and advantages.

In this article, we develop the COPRAS model to solve the multiple attribute group decision making (MAGDM) under single-valued neutrosophic 2-tuple linguistic sets (SVN2TLSs). Firstly, we introduce the relevant knowledge about SVN2TLSs in a nutshell, such as the definition, the operation laws, a few of fused operators and so on. Then, combine the traditional COPRAS model with SVN2TLNs, and structure as well as elucidate the computing steps of the SVN2TLNCOPRAS pattern. Furthermore, in this article, we propose a method for determining attribute weights in different situations relying on the maximizing deviation method with SVN2TLNs. Last but not least, a numerical example about assessing the safety of construction project has been designed. And for further demonstrating the advantage of the new designed method, we also select a number of existed methods to have comparisons. First published online 13 January 2021