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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.

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

Probabilistic linguistic term sets are used to express uncertain decision information in multiple attribute group decision making problems. For probabilistic linguistic multiple attribute group decision making (MAGDM) with weight determined by CRITIC (Criteria Importance Through Intercriteria Correlation) method, the probabilistic linguistic grey relational projection method is proposed in this paper. Firstly, the correlation coefficient among attributes and standard deviation of each attribute are utilized to compute the attributes weights. Then the most ideal alternative is decided by means of counting the grey relational projection (GRP) from probabilistic linguistic positive ideal solution and probabilistic linguistic negative ideal solution. In the end, a numerical example for site selection of hospital constructions is applied to further account for the extended method. The result demonstrates the availability of the proposed method and it can be used in other fields which refers to problems of selection.

The paper corrugation tube is an innovative kind of energy absorbing structure and shock absorber which can play an important role on the cushioning energy absorption for airdrop equipments and transportation packaging. The deformation characteristics and failure modes of the regular triangle, quadrangle, pentagon and hexagon paper corrugation tubes were comparatively studied by a series of axial static compression experiments, the cushioning energy absorption was evaluated by the seven characteristic parameters (e.g. initial peak force, mean crush force, total energy absorption, specific energy absorption, crush force efficiency, unit area energy absorption and stroke efficiency), and the influences of tube direction, cross-sectional shape, tube length and compression rate on failure modes and cushioning energy absorption were analyzed and compared. These researches showed that the tubes along X direction only have the accordion deformation mode, yet the tubes along Y direction have four deformation modes including steady state progressive buckling, Euler buckling, angular tear and transverse shear. For the paper corrugation tubes along Y direction, the cross-sectional shape has obvious influence on the cushioning energy absorption of structures, and the specific energy absorption and unit area energy absorption of regular triangle and pentagon tubes are better than those of the tubes with regular quadrilateral and hexagonal cross-section at compression rates of 12 and 48mm/min. The tube length of 150 mm or compression rate of 72 mm/min would cause the increase of contribution proportion of non-ideal deformation mode and the decrease of cushioning properties. The paper corrugation tubes along X direction have more stable and controllable deformation mode, yet the paper corrugation tubes along Y direction have better cushioning energy absorption.

Since people around the world have gradually attached importance to resource conservation, various countries are actively taking measures to promote environmental protection and sustainable development. Green supply chain management (GSCM) have emerged in this context. Thus, in this essay, a novel intuitionistic fuzzy multiple attribute group decision making (MAGDM) method is designed to tackle this issue. First of all, CRITIC (Criteria Importance Through Inter-criteria Correlation) method is utilized to determine the weights of criteria. Later, the conventional Taxonomy method is extended to the intuitionistic fuzzy environment to compute the value of development attribute of each supplier. Then, the optimal one can be determined. Eventually, an application about green supplier selection in steel industry is presented, and a comparative analysis is made to demonstrate the superiority of the proposed method. The main features of the proposed algorithm are that they provide a practical solution for selecting GSCM and presents an objective weighting method to enhance the effectiveness of the algorithm.

Probabilistic uncertain linguistic sets (PULTSs) have extensively been employed in multiple attribute group decision making (MAGDM)problem. The QUALIFLEX method, which is relatively a novel MAGDM technique, aims to obtain the optimal alternative. This paper proposes the probabilistic uncertain linguistic QUALIFLEX (PUL-QUALIFLEX) method with CRITIC method. To show the effectiveness of the designed method, an application is given for green supplier selection and the derived results are compared with some existing methods. Thus, the advantage of this proposed method is that it is simple to understand and easy to compute. The proposed method can also contribute to the selection of suitable alternative successfully in other selection issues.

In recent years, with the increased voice for protecting the environment by the people all over the world, the governments also have actively adopted more and more measures to further promote environmental conservation and sustainable development. Traditional procurement approaches have not well updated to the current needs of the society, especially for the retail industry which is in relation to the national economy due to numerous products and different suppliers being involved. Therefore, the need for green procurement is more important. The qualified green supplier selection is the core of green procurement, which is the utmost importance in the business competition throughout the supply chain in today’s strong business competition. Thus, in order to obtain the optimal green supplier, integration of Entropy weights and multi-attributive border approximation area comparison (MABAC) under uncertain probabilistic linguistic sets (UPLTSs) has offered a novel integrated model, in which information Entropy is utilized for calculating objective weights with UPLTSs to acquire the final ranking result of green supplier. Besides, so as to indicate the applicability of devised method, it is confirmed by a numerical case for green supplier selection. Some comparative studies are made with some existing methods. The proposed method can also serve for selecting suitable alternative successfully in other selection problems.

In this paper, we provide the probabilistic linguistic multiple attribute group decision making (PL-MAGDM) with incomplete weight information. In such method, the linguistic information firstly is shifted into probabilistic linguistic information. For obtaining the weight information of the attribute, two optimization models are built on the basis of the basic idea of grey relational analysis (GRA), by which the attribute weights can be obtained. Then, the optimal alternative is obtained through calculating largest relative relational degree from the probabilistic linguistic positive ideal solution (PLPIS) which considers both the largest grey relational coefficient (GRC) from the PLPIS and the smallest GRC form probabilistic linguistic negative ideal solution (PLNIS). Finally, a case study for waste incineration plants location problem is given to demonstrate the advantages of the developed methods.

Using external stimulants to tune the structural and physical properties of chalcogenides has become a hot research topic due to the potential applications in high-temperature superconductors and g...

Topological nodal-line semimetals (TNLSMs) are materials whose conduction and valence bands cross each other, meeting a topologically protected closed loop rather than discrete points in the Brillouin zone (BZ). The anticipated properties for TNLSMs, include drumhead-like nearly flat surface states, unique Landau energy levels, special collective modes, long-range Coulomb interactions, or the possibility of realizing high-temperature superconductivity. Recently, SrAs3 has been theoretically proposed and then experimentally confirmed to be a TNLSM. Here, we report high-pressure experiments on SrAs3, identifying a Lifshitz transition below 1 GPa and a superconducting transition accompanied by a structural phase transition above 20 GPa. A topological crystalline insulator (TCI) state is revealed by means of density functional theory (DFT) calculations on the emergent high-pressure phase. As the counterpart of topological insulators, TCIs possess metallic boundary states protected by crystal symmetry, rather than time reversal. In consideration of topological surface states (TSSs) and helical spin texture observed in the high-pressure state of SrAs3, the superconducting state may be induced in the surface states, and is most likely topologically nontrivial, making pressurized SrAs3 a strong candidate for topological superconductor.

The electronic structure of the natural topological semimetal Co3Sn2S2crystals was studied by using near-edge X-ray absorption spectroscopy (NEXAFS) and resonant photoelectron spectroscopy (ResPES). Although, the significant increase of the Co 3d valence band emission is observed at the Co 2p absorption edge in the ResPES experiments, the spectral weight at these photon energies is dominated by the normal Auger contribution. This observation indicates the delocalized character of photoexcited Co 3d electrons and is supported by the first-principle calculations. Our results on the investigations of the element- and orbital-specific electronic states near the Fermi level of Co3Sn2S2are of importance for the comprehensive description of the electronic structure of this material, which is significant for its future applications in different areas of science and technology, including catalysis and water splitting.

In recent years, a series of serious attacks against industrial control system (ICS), such as Stuxnet, Duqu, Flame and Havex, have sounded the alarm for industrial enterprises. For many industrial enterprises, it is a very important part of enterprise management decisions to evaluate ICS security suppliers and choose the appropriate one as a partner. The purpose of this paper is to build the TODIM method based on cumulative prospect theory (CPT-TODIM) to solve multiattribute group decision making problem under interval-valued bipolar fuzzy environment. This extraordinary model not only uses CPT to supplement the traditional TODIM method, but also introduces the entropy weight method to determine the attribute weight so as to avoid the negative influence of subjective weight on the decision result. In addition, in this model, all attribute evaluation information will be interval-valued bipolar fuzzy number (IVBFN) to cope with complex and fuzzy decision environment. Then, the most important part of this paper, we elaborate on the logical structure of the model. What’s more, in the last two sections, we apply this newly constructed model to the selection of ICS security suppliers, and verify the acceptability of this method by sensitivity analysis and comparing with IVBFWA and IVBFWG operator. First published online 05 July 2021

We report magnetic, transport, neutron diffraction, and muon spin rotation data showing that Pb$_2$CoOsO$_6$, a newly synthesized metallic double-perovskite with a centrosymmetric space group at room temperature, exhibits a continuous second-order phase transition at 45 K to a magnetically ordered state with a non-centrosymmetric space group. The absence of inversion symmetry is very uncommon in metals, particularly metallic oxides. In contrast to the recently reported ferroelectric-like structural transition in LiOsO$_3$, the phase transition in Pb$_2$CoOsO$_6$ is driven by a long-range collinear antiferromagnetic order, with propagation vector $\textbf{k} = (\frac{1}{2},0,\frac{1}{2})$, which relieves the frustration associated with the symmetry of themagnetic exchanges. This magnetically-driven loss of inversion symmetry represents a new frontier in the search for novel metallic behavior., 5 pages, 3 figures

Dirac semimetals (DSMs) are classified into different phases based on the types of the Dirac fermions. Tuning the transition among different types of the Dirac fermions in one system remains challenging. Recently, KMgBi was predicted to be located at a critical state that various types of Dirac fermions can be induced owing to the existence of a flat band. Here, we carried out systematic studies on the electronic structure of KMgBi single crystal by combining angle-resolve photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS). The flat band was clearly observed near the Fermi level. We also revealed a small bandgap of ~ 20 meV between the flat band and the conduction band. These results demonstrate the critical state of KMgBi that transitions among various types of Dirac fermions can be tuned in one system., 15 pages, 4 figures

Using angle-resolved photoemission spectroscopy and band structure calculation, we have investigated the three-dimensional nature and the orbital character of the low-energy electronic structure in the layered ternary boride ${\mathrm{AlMn}}_{2}{\mathrm{B}}_{2}$, in which ferromagnetic Mn $ab$ layers couple antiferromagnetically along the $c$ axis (N\'eel temperature ${\mathrm{T}}_{\mathrm{N}}\ensuremath{\sim}320\phantom{\rule{0.28em}{0ex}}\mathrm{K}$). The calculation indicates that electronic bands in the vicinity of the Fermi energy ${E}_{\mathrm{F}}$ are dominated by the Mn $3d$ orbitals. The ${e}_{g}$ orbitals especially contribute high density of states (DOS) with large effective electron masses near ${E}_{\mathrm{F}}$. The calculated bands are renormalized by a factor of $\ensuremath{\sim}1.5$ to match the overall experimental observations, indicating moderate electronic correlation. Considering that the neighbor compound ${\mathrm{AlFe}}_{2}{\mathrm{B}}_{2}$, with one more $3d$ electron, is ferromagnetic, the high DOS near ${E}_{\mathrm{F}}$ from the different $3d$ orbitals should be associated with the different magnetic orders along the special directions in these layered ternary borides. On the other hand, our studies of electronic structure of ${\mathrm{AlMn}}_{2}{\mathrm{B}}_{2}$ would further prompt its potential applications as a layered room-temperature antiferromagnetic material.

Topological materials host fascinating low dimensional gapless states at the boundary. As a prominent example, helical topological edge states (TESs) of two-dimensional topological insulators (2DTIs) and their stacked three-dimensional (3D) equivalent, weak topological insulators (WTIs), have sparked research enthusiasm due to their potential application in the next generation of electronics/spintronics with low dissipation. Here, we propose layered superconducting material CaSn as a WTI with nontrivial Z2 as well as nodal line semimetal protected by crystalline non-symmorphic symmetry. Our systematic angle-resolved photoemission spectroscopy (ARPES) investigation on the electronic structure exhibits excellent agreement with the calculation. Furthermore, scanning tunnelling microscopy/spectroscopy (STM/STS) at the surface step edge shows signatures of the expected TES. These integrated evidences from ARPES, STM/STS measurement and corresponding ab initio calculation strongly support the existence of TES in the non-symmorphic nodal line semimetal CaSn, which may become a versatile material platform to realize multiple exotic electronic states as well as topological superconductivity.

The noncentrosymmetric RAlPn (R = rare earth, Pn = Si, Ge) family, predicted to host nonmagnetic and magnetic Weyl states, provide an excellent platform for investigating the relation between magnetism and Weyl physics. By using high field magnetotransport measurements and first principles calculations, we have unveiled herein both type-I and type-II Weyl states in the nonmagnetic LaAlSi. By a careful comparison between experimental results and theoretical calculations, nontrivial Berry phases associated with the Shubnikov-de Haas oscillations are ascribed to the electron Fermi pockets related to both types of Weyl points located ~ 0.1 eV above and exactly on the Fermi level, respectively. Under high magnetic field, signatures of Zeeman splitting are also observed. These results indicate that, in addition to the importance for exploring intriguing physics of multiple Weyl fermions, LaAlSi as a comparison with magnetic Weyl semimetals in the RAlPn family would also yield valuable insights into the relation between magnetism and Weyl physics., Comment: 18 pages, 5 figures, 1 table

Two-dimensional (2D) materials with narrow band gaps (∼0.3 eV) are of great importance for realizing ambipolar transistors and mid-infrared (MIR) detections. However, most of the 2D materials studied to date have band gaps that are too large. A few of the materials with suitable band gaps are not stable under ambient conditions. In this study, the layered Nb2SiTe4 is shown to be a stable 2D material with a band gap of 0.39 eV. Field-effect transistors based on few-layer Nb2SiTe4 show ambipolar transport with a similar magnitude of electron and hole current and a high charge-carrier mobility of ∼100 cm2 V-1 s-1 at room temperature. Optoelectronic measurements of the devices show clear response to an MIR wavelength of 3.1 μm with a high responsivity of ∼0.66 AW-1. These results establish Nb2SiTe4 as a good candidate for ambipolar devices and MIR detection.

The vibration transmissibility of paper honeycomb sandwich plate was tested and the vibration transmissibility curve was simplified and characterized. Based on the basic principle of vibration mechanics, the equation for calculating the energy dissipated by damping of paper honeycomb sandwich plate-block system during vibration was deduced. Furthermore, the effects of honeycomb structural parameters (cell length, sandwich plate thickness) and block mass on the damping energy dissipation were analyzed. The results showed that the curves of vibration transmissibility for paper honeycomb sandwich plate can be divided into three regions: plateau region, amplification region, and attenuation region. The vibration transmissibility ratio in different regions can be expressed as functions of frequency. The energy dissipated by damping of paper honeycomb sandwich plate-block system depends on its vibration transmissibility. If the vibration transmissibility ratio–frequency curve is obtained, the damping energy dissipation of the system can be calculated. The total energy dissipation of paper honeycomb sandwich plate-block system during vibration is about equal to that of plateau region, and the energy dissipated in amplification and attenuation region can be neglected. Different honeycomb structural parameters have the same effect on the damping energy dissipation of the system. Block mass has little effect on the damping energy dissipation in plateau region and the total energy dissipation during vibration but has a greater impact on the energy dissipation in the amplification and attenuation regions. The purpose of this paper is to provide a basic method for calculation of energy dissipated by damping and evaluation of anti-vibration property for packaging material.

In view of cushioning energy absorption of paper composite sandwich structures with sinusoidal corrugation and hexagonal honeycomb cores, the static yield strength and compression deformation were firstly analyzed by experiments, then the unit volume energy absorption, unit area energy absorption, and specific energy absorption were evaluated. Further, the influences of static compression rate, corrugation types, and honeycomb thickness on the cushioning energy absorption were respectively studied. The experimental observations show that the paper composite sandwich structures are crushed layer by layer due to the difference in the yield strength of sandwiches, and the honeycomb core is crushed after the collapsing of corrugation core. The three evaluation indices of cushioning energy absorption have similar change rule with the compression rate, corrugation types, and honeycomb thickness. The influence of static compression rate on the yield strength and cushioning energy absorption of the paper composite sandwich structure is not obvious. The composite sandwich structures consisting of paper corrugation sandwich with large inertia moment and honeycomb sandwich with large thickness have more excellent cushioning energy absorption, the B-corrugation can increase the unit volume energy absorption of paper composite sandwich structures by up to 18% than C-corrugation, and the 3-honeycomb can increase the unit volume energy absorption of paper composite sandwich structures by up to 32% than 2-honeycomb.

Layered transition-metal trichalcogenides have become one of the research frontiers as two-dimensional magnets and candidate materials used for phase-change memory devices. Herein we report the high-pressure synchrotron X-ray diffraction and resistivity measurements on Cr2Ge2Te6 (CGT) single crystal by using diamond anvil cell techniques, which reveal a mixture of crystalline-to-crystalline and crystalline-to-amorphous transitions taking place concurrently at 18.3-29.2 GPa. The polymorphic transition could be interpreted by atomic layer reconstruction and the amorphization could be understood in connection with randomly flipping atoms into van der Waals gaps. The amorphous (AM) phase is quenchable to ambient conditions. The electrical resistance of CGT shows a bouncing point at ~ 18 GPa, consistent with the polymorphism phase transition. Interestingly, the high-pressure AM phase exhibits metallic resistance with the magnitude comparable to that of high-pressure crystalline phases, whereas the resistance of the AM phase at ambient pressure fails to exceed that of the crystalline phase, indicating that the AM phase of CGT appeared under high pressure is quite unique and similar behavior has never been observed in other phase-change materials. The results definitely would have significant implications for the design of new functional materials., 14 pages,7 figures, 2 tables, 1 supporting information. JPCC in press

The composite layered structures including paper corrugation, paper honeycomb and expandable polyethylene are innovative structures of cushioning energy absorption, and the compression and impact resistances of the expandable polyethylene can be enhanced by laminating the corrugated paperboard or honeycomb paperboard. This article evaluated the compression performance and cushioning energy absorption of the composite layered structures by the static compression and drop impact compression tests. On one hand, the static compression properties showed that the total energy absorption, energy absorption per unit volume and stroke efficiency of the composite layered structures were all higher than those of expandable polyethylene. The specific energy absorption was enhanced with the increase in compression strain but almost not affected by the compression rate. The specific energy absorption of the composite layered structures including the expandable polyethylene and honeycomb paperboard was greater than those of the expandable polyethylene and corrugated paperboard. The energy absorption efficiency of the composite layered structures including the expandable polyethylene and corrugated paperboard was large for the low compression stress level, yet that of the composite layered structures including the expandable polyethylene and honeycomb paperboard was large for the high compression stress level. On the other hand, the dynamic compression characteristics showed that the peak stress, energy absorption per unit area, energy absorption per unit volume and specific energy absorption of the composite layered structures embodying paper sandwich cores and expandable polyethylene had linear increasing trends with the increase of drop shock energy. At the same drop impact condition, the composite layered structures including the honeycomb paperboard and expandable polyethylene had better cushioning energy absorption, the peak stress decreased by 23.6% on average, the energy absorption efficiency raised by 8.85% on average and the specific energy absorption increased by 18.1% on average than those including the corrugated paperboard and expandable polyethylene. Therefore, the corrugated paperboard and honeycomb paperboard can helpfully improve the cushioning energy absorption of the expandable polyethylene, and the composite layered structures embodying the expandable polyethylene, corrugated paperboard and honeycomb paperboard may hold excellent packaging protection.

The finite element model for paper honeycomb was constructed, and the finite element method of out-of-plane compression for the paper honeycomb was studied. Then four kinds of paper honeycomb with different structural parameters were simulated and analyzed using finite element software ABAQUS. Moreover, the results obtained from finite element method were verified based on the existing theoretical research results and experimental results, respectively. The results show that stress–strain curves obtained from finite element method clearly show the four deformation stages of the paper honeycomb under out-of-plane compression, which is basically consistent with the trend of the typical curve. The values of initial peak stress, plateau stress and densification strain are close to the theoretical results. The stress–strain curves and deformation contours coincide with experiments well. The differences of initial peak stress σpk, plateau stress σpl and densification strain εD between theoretical, finite element method and experimental results are less than 15%. Therefore, the finite element method can be used to analyze the stress–strain curves and deformation characteristics of paper honeycomb. In addition, the results also show that the thickness of specimen has little effect on the stress and strain. However, people often prefer to use the thicker paper honeycomb to get better cushioning effect in practical applications, which was explained.

We present extensive investigations of the crystallographic phase diagram and electronic properties of the Fe-based superconductor FeSe under extreme conditions (high pressure (HP) and low temperature (LT)) by synchrotron X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). An isostructural phase transition (Tetragonal (T) →high-pressure Tetragonal (Tʹ)) is discovered in FeSe at ∼2.8 GPa based on the axial ratio c/a with finer pressure step as observed in Fe-As-based superconductor such as EuFe2As2. We also find a pressure-induced Tʹ → MnP-type phase transition at 7.6 GPa in FeSe, which is consistent with the documented pressure-induced high-spin → low-spin transition (∼6–7 GPa). These results reveal the pressure-induced structural phase transition sequence in FeSe at room temperature to be T → Tʹ → Tʹ+MnP-type at pressures of 0–10.6 GPa, enriching the crystallographic phase diagram. The HPLT XRD data also indicate that a sluggish structural phase transition (Cmma → Pnma) begins at 7.5 GPa, and these two phases coexist up to 26.5 GPa. The HP X-ray absorption near-edge spectroscopy (XANES) measurement shows that Eo of Se experiences a pressure-induced shift to high energy, evidencing strongly charge transfer between Fe and Se under high pressure. Our results shed lights on the correlation between crystallographic/electronic structure and superconductivity in this material.

Recently, layered copper chalcogenides ${\mathrm{Cu}}_{2}X$ family $(X=\mathrm{S}, \mathrm{Se}, \mathrm{Te})$ has attracted tremendous research interests due to their high thermoelectric performance, which is partly due to the superionic behavior of mobile Cu ions, making these compounds ``phonon liquids.'' Here, we systematically investigate the electronic structure and its temperature evolution of the less studied single crystal ${\mathrm{Cu}}_{2\ensuremath{-}x}\mathrm{Te}$ by the combination of angle resolved photoemission spectroscopy (ARPES) and scanning tunneling microscope/spectroscopy (STM/STS) experiments. While the band structure of the ${\mathrm{Cu}}_{2\ensuremath{-}x}\mathrm{Te}$ shows agreement with the calculations, we clearly observe a $2\ifmmode\times\else\texttimes\fi{}2$ surface reconstruction from both our low temperature ARPES and STM/STS experiments which survives up to room temperature. Interestingly, our low temperature STM experiments further reveal multiple types of reconstruction patterns, which suggests the origin of the surface reconstruction being the distributed deficiency of liquidlike Cu ions. Our findings reveal the electronic structure and impurity level of ${\mathrm{Cu}}_{2}\mathrm{Te}$, which provides knowledge about its thermoelectric properties from the electronic degree of freedom.

Probabilistic uncertain linguistic sets (PULTSs) have widely been used in MADM or MAGDM. The CODAS method, which is a novel MADM or MAGDM tool, aims to acquire the optimal choice which have the largest Euclidean & Hamming distances from the NIS. This paper designs the probabilistic uncertain linguistic CODAS (PUL-CODAS) method with sine entropy weight. Finally, a numerical example for green supplier selection is given and the obtained results are compared with some existing models. First published online 05 February 2021

The newfound two-dimensional antiferromagnetic $\mathrm{Gd}{\mathrm{Te}}_{3}$ has great potential in novel magnetic twistronic and spintronic devices because it has the highest carrier mobility among all known layered magnetic materials. Here, we used high-resolution angle-resolved photoemission spectroscopy to investigate its Fermi-surface topology and low-lying electronic band structure. The Fermi surface is partially gapped by charge-density waves below the transition temperature. Very steep and nearly linear band dispersion near the Fermi energy contributes to the high carrier mobility in $\mathrm{Gd}{\mathrm{Te}}_{3}$. We find that the scattering rate of the quasiparticle increases linearly as a function of binding energy within a wide energy range, indicating that $\mathrm{Gd}{\mathrm{Te}}_{3}$ is a non-Fermi-liquid metal. Our results in this paper provide a fundamental understanding of this layered antiferromagnetic material to guide future studies on it.

Layered structural materials have been a fertile playground to investigate mechanisms of fundamental physics and explore potential applications. Here, we report investigations on ferromagnetic van der Waals $\mathrm{Cr}\mathrm{Si}{\mathrm{Te}}_{3}$ via high-pressure synchrotron x-ray diffraction, electrical resistance, and magnetoresistance measurements. Under compression, $\mathrm{Cr}\mathrm{Si}{\mathrm{Te}}_{3}$ undergoes an insulator-metal transition and a structural transition at $\ensuremath{\sim}7.5$ GPa. Concomitantly with the structural transition, the magnetoresistance changes sign, the negative Hall coefficient increases dramatically, and superconductivity emerges at 3 K. The superconductivity persists up to the highest measured pressure of 47.1 GPa with a maximum ${T}_{c}\ensuremath{\approx}$ 4.5 K at $\ensuremath{\sim}30$ GPa. Our results suggest that $\mathrm{Cr}\mathrm{Si}{\mathrm{Te}}_{3}$ is paramagnetic in the pressure range of superconductivity. The discoveries of superconductivity and magnetic transition in ferromagnetic $\mathrm{Cr}\mathrm{Si}{\mathrm{Te}}_{3}$ under pressure provide new perspectives to explore the interplay between superconductivity and magnetism in Cr-based two-dimensional van der Waals materials.

${\mathrm{Pb}}_{2}\mathrm{Co}\mathrm{Os}{\mathrm{O}}_{6}$ is a newly synthesized polar metal in which inversion symmetry is broken by the magnetic frustration in an antiferromagnetic ordering of Co and Os sublattices. The coupled magnetic and structural transition occurs at 45 K at ambient pressure. Here, we perform transport measurements and first-principles calculations to study the pressure effects on the magnetic/structural coupled transition of ${\mathrm{Pb}}_{2}\mathrm{Co}\mathrm{Os}{\mathrm{O}}_{6}$. Experimentally, we monitor the resistivity anomaly at ${T}_{N}$ under various pressures up to 11 GPa in a cubic anvil cell apparatus. We find that ${T}_{N}$ determined from the resistivity anomaly first increases quickly with pressure in a large slope of $d{T}_{N}/dP=+6.8(8)\phantom{\rule{0.28em}{0ex}}\mathrm{K}/\mathrm{GPa}$ for $Pl4\phantom{\rule{0.28em}{0ex}}\mathrm{GPa}$ and, then, increases with a much reduced slope of 1.8(4) K/GPa above 4 GPa. Our first-principles calculations suggest that the observed discontinuity of $d{T}_{N}/dP$ around 4 GPa may be attributed to the vanishing of the Os magnetic moment under pressure. Pressure substantially reduces the Os moment and completely suppresses it above a critical value, which relieves the magnetic frustration in the antiferromagnetic ordering of ${\mathrm{Pb}}_{2}\mathrm{Co}\mathrm{Os}{\mathrm{O}}_{6}$. The Co and Os polar distortions decrease with the increasing pressure and simultaneously vanish at the critical pressure. Therefore, above the critical pressure, a new centrosymmetric antiferromagnetic state emerges in ${\mathrm{Pb}}_{2}\mathrm{Co}\mathrm{Os}{\mathrm{O}}_{6}$, distinct from the one under ambient pressure, thus, showing a discontinuity in $d{T}_{N}/dP$.

Orthorhombic (space group: Pnma) Nb2P5 is a high-pressure phase that is quenchable to ambient pressure, which could viewed as the zigzag infinite P chain-inserted NbP2. We report herein the high-pressure crystal growth of Nb2P5 and the discovery of its superconducting transition at Tc ~ 2.6 K. The electrical resistivity, magnetization, and specific heat capacity measurements on the high-quality crystal unveiled a conventional type-II weakly coupled s-wave nature of the superconductivity, with the upper critical field Hc2(0) ~ 0.5 T, the electron-phonon coupling strength {\lambda}ep ~ 0.5 - 0.8, and the Ginzburg-Landau parameter \k{appa} ~ 100. The ab initio calculations on the electronic band structure unveiled nodal-line structures protected by different symmetries. The one caused by band inversion, for example, on the {\Gamma}-X and U-R paths of the Brillouin zone, likely could bring nontrivial topology and hence possible nontrivial surface state on the surface. The surface states on the (100), (010) and (110) surfaces were also calculated and discussed. The discovery of the phosphorus-rich Nb2P5 superconductor would be instructive for the design of more metal phosphides superconductors which might host unconventional superconductivity or potential technical applications., Comment: 8 pages,8 figures in the main text + 4 pages, 3 figures, 1 table in the supplementary information

In this article, we combine some fundamental theories of the Pythagorean 2-tuple linguistic sets (P2TLSs) with EDAS method and design the Pythagorean 2-tuple linguistic number (P2TLN) EDAS (P2TLN-EDAS) method for multiple attribute group decision making (MAGDM) issue. Firstly, the basic concepts of P2TLSs are introduced. Next, two aggregation operators of P2TLN are defined, and then the calculation steps of EDAS method are listed briefly. Furthermore, P2TLN-EDAS method is given for MAGDM problems and computing steps are proposed in detail. Finally, a computational example related to construction safety assessment is used to expound the effectiveness of the designed method. Meanwhile, we also carried out some comparative analysis between P2TLN-EDAS method and P2TLWA/P2TLWG operators and another P2TLN-TODIM method. The results show that P2TLN-EDAS method derives the same best alternative as P2TLWA, P2TLWG operators and P2TLN-TODIM method. First published online 24 September 2020

There has been an upsurge in the discovery of topological quantum materials, where various topological insulators and semimetals have been theoretically predicted and experimentally observed. However, very few of them contain silicon, the most widely used element in the electronics industry. Recently, ternary compound $\mathrm{CaA}{\mathrm{l}}_{2}\mathrm{S}{\mathrm{i}}_{2}$ has been predicted to be a topological Dirac semimetal, hosting Lorentz-symmetry-violating quasiparticles with a strongly tilted conical band dispersion. In this work, by using high-resolution angle-resolved photoemission spectroscopy, we investigated the comprehensive electronic structure of $\mathrm{CaA}{\mathrm{l}}_{2}\mathrm{S}{\mathrm{i}}_{2}$. A pair of topological Dirac crossings is observed along the ${k}_{z}$ direction, in good agreement with the ab initio calculations, confirming the topological Dirac semimetal nature of the compound. Our study expands the topological material family on Si-containing compounds, which have great application potential in realizing low-cost, nontoxic electronic devices with topological quantum states.

We have investigated the magnetic correlations in the candidate Weyl semimetals ${\mathrm{EuCd}}_{2}P{n}_{2}$ ($Pn=\mathrm{As}$, Sb) by resonant elastic x-ray scattering at the ${\mathrm{Eu}}^{2+}$ ${M}_{5}$ edge. The temperature and field dependence of the diffuse scattering of ${\mathrm{EuCd}}_{2}{\mathrm{As}}_{2}$ provide direct evidence that the Eu moments exhibit slow ferromagnetic (FM) correlations well above the N\'eel temperature. By contrast, the diffuse scattering in the paramagnetic phase of isostructural ${\mathrm{EuCd}}_{2}{\mathrm{Sb}}_{2}$ is at least an order of magnitude weaker. The FM correlations present in the paramagnetic phase of ${\mathrm{EuCd}}_{2}{\mathrm{As}}_{2}$ could create short-lived Weyl nodes.

We reveal an ultrafast purely electronic phase transition in ${\mathrm{Ta}}_{2}{\mathrm{NiSe}}_{5}$, which is a plausible excitonic insulator, after excited by an ultrafast infrared laser pulse. Specifically, the order parameter of the strong electron-hole binding shrinks with enhancing the pump pulse, and above a critical pump fluence, a photoexcited semimetallic state is experimentally identified with the absence of ultrafast structural transition. In addition, the bare valence and conduction bands and also the effective masses in ${\mathrm{Ta}}_{2}{\mathrm{NiSe}}_{5}$ are determined. These findings and detailed analysis suggest a bare nonequilibrium semimetallic phase in ${\mathrm{Ta}}_{2}{\mathrm{NiSe}}_{5}$ and the strong electron-hole binding cannot be exclusively driven by Coulomb interaction.

${\mathrm{AlFe}}_{2}{\mathrm{B}}_{2}$, a layered ferromagnet with a Curie temperature near room temperature (${T}_{c}\ensuremath{\sim}270$ K), has attracted growing attention recently in condensed-matter physics and materials science. Utilizing angle-resolved photoemission spectroscopy and first-principles calculations, we provide evidence of a linear band and a saddlelike flat band in the vicinity of the Fermi energy (${E}_{F}$) in ${\mathrm{AlFe}}_{2}{\mathrm{B}}_{2}$, consisting of slabs of ${\mathrm{Fe}}_{2}{\mathrm{B}}_{2}$ atoms separated by layers of Al. The anomalous scattering rate of the linear band varies linearly with the kinetic energy up to 120 meV, showing non-Fermi-liquid behavior consistent with T-linear dependence of resistivity. The flat band with ${d}_{xy}$ orbital character and with strong ${k}_{y}$ dispersion may be associated with spin orientation along the $a$ axis in layered ${\mathrm{AlFe}}_{2}{\mathrm{B}}_{2}$. Electronic and magnetic correlation can be modulated by tuning the flat band near ${E}_{F}$ in layered ternary borides. Our findings have important implications to exploit emergent physics and quantum phases in $3d$ transition metals.

We report herein the results of magnetotransport measurements and ab initio calculations on single crystalline $\mathrm{CaA}{\mathrm{l}}_{2}\mathrm{S}{\mathrm{i}}_{2}$ semimetal. The transport properties could be understood in connection with the two-band model, agreeing well with the theoretical calculations indicating four main sheets of Fermi surface consisting of three hole pockets centered at the $\mathrm{\ensuremath{\Gamma}}$ point and one electron pocket centered at the $M$ point in the Brillouin zone. Magnetotransport measurements showed striking Shubnikov--de Haas oscillations associated with a nontrivial Berry phase, which originate from a hole Fermi pocket indicated by the ab initio calculations. The calculations also unveiled that the hole Fermi surface encloses a nodal line setting around the $\mathrm{\ensuremath{\Gamma}}$ point close to the Fermi level without considering the spin-orbit coupling (SOC). Once the SOC is included, the fragile nodal-line will be gapped and a pair of Dirac points emerge along the high symmetric $\mathrm{\ensuremath{\Gamma}}\text{\ensuremath{-}}A$ direction located at the Brillouin zone coordinates (0, 0, ${k}_{z}^{D}\ensuremath{\approx}\ifmmode\pm\else\textpm\fi{}0.278\phantom{\rule{4pt}{0ex}}\ifmmode\times\else\texttimes\fi{}\frac{2\ensuremath{\pi}}{c}$), about 1.22 eV below the Fermi level. In addition, the SOC can also induce a topological insulator state along the $\mathrm{\ensuremath{\Gamma}}\text{\ensuremath{-}}A$ direction with a gap of about 3 meV. The results demonstrate $\mathrm{CaA}{\mathrm{l}}_{2}\mathrm{S}{\mathrm{i}}_{2}$ as an excellent platform for the study of novel topological physics with multiple nontrivial topological states.

The van der Waals ferromagnet $\mathrm{F}{\mathrm{e}}_{3}\mathrm{GeT}{\mathrm{e}}_{2}$ has attracted great research attention recently due to its extraordinary properties. Here, using high-resolution angle-resolved photoemission spectroscopy, we systematically investigate the temperature evolution of the electronic structure of bulk $\mathrm{F}{\mathrm{e}}_{3}\mathrm{GeT}{\mathrm{e}}_{2}$. We observe largely dispersive energy bands with exchange splitting that are in overall agreement with our density-functional theory calculation. Interestingly, the band dispersions barely change upon heating towards the ferromagnetic transition near 225 K, except for the reduction of quasiparticle coherence, which strongly deviates from the itinerant Stoner model. We suggest that the local magnetic moments may play a crucial role in the ferromagnetic ordering and the electronic structure of $\mathrm{F}{\mathrm{e}}_{3}\mathrm{GeT}{\mathrm{e}}_{2}$, which will shed light on the generic understanding of itinerant magnetism in correlated materials.

High-magnetic-field transport measurements and ab initio calculations on the layered superconductor TaSe3 have provided evidence for the existence of a three-dimensional strong topological state. Longitudinal magnetotransport measurements up to similar to 33 T unveiled striking Shubnikov-de Haas oscillations with two fundamental frequencies at 100 and 175 T corresponding to a nontrivial hole Fermi pocket at the Gamma point and a nontrivial electron Fermi pocket at the B point, respectively, in the Brillouin zone. However, calculations revealed one more electron pocket at the B point which was not detected by the magnetotransport measurements, presumably due to the limited carrier momentum relaxation time. Angle-dependent quantum oscillations by rotating the sample with respect to the magnetic field revealed clear changes in the two fundamental frequencies, indicating anisotropic electronic Fermi pockets. The ab initio calculations gave the topological Z(2) invariant of (1; 100) and revealed a single Dirac cone on the (1 0 -1) surface at the (X) over bar point with helical spin texture at a constant energy contour, suggesting a strong topological state. The results demonstrate TaSe3 as an excellent platform to study the interplay between the topological phase and superconductivity and a promising system for the exploration of topological superconductivity.

Pyrite-structured PdSb2 with the nonsymmorphic crystalline symmetry, has long been predicted to host sixfold-degenerate exotic fermions beyond Dirac and Weyl. Although magnetotransport measurements on PdSb2 have suggested its topologically nontrivial character, the direct spectroscopic evidence still remains absent. By utilizing high-resolution angle-resolved photoemission spectroscopy, we present a systematic study on the low-energy bulk and surface electronic structure of pyrite-structured PdSb2. Through careful comparison with first-principles calculations, we verify the existence of sixfold fermions in this compound, which are formed by three doubly degenerate bands centered at the R point in the Brillouin zone. These bands exhibit parabolic dispersion close to sixfold fermion nodes, in sharp contrast to previously reported sixfold double spin-1 chiral fermions. Furthermore, our findings reveal no protected Fermi arcs in PdSb2, which is compatible with its achiral structure. Our findings suggest that pyrite-structured PdSb2 provides an ideal platform for the investigation of fermions and their potential applications.

The three-dimensional and temperature-dependent electronic structures of the heavy-fermion superconductor ${\mathrm{CePt}}_{2}{\mathrm{In}}_{7}$ are investigated. Angle-resolved photoemission spectroscopy using variable photon energy establishes the existence of quasi-two- and three-dimensional Fermi surface topologies. Temperature-dependent $4d\text{\ensuremath{-}}4f$ on-resonance photoemission spectroscopies data reveal that heavy quasiparticle bands begin to form at a temperature well above the characteristic (coherence) temperature ${T}^{*}$. The emergence of low-lying crystal electric field excitation may be responsible for the ``relocalization'' or the precursor to the establishment of heavy electrons coherence in heavy-fermion compounds. These findings provide critical insight into understanding the hybridization in heavy-fermion systems.

The van der Waals ferromagnet Fe5GeTe2 has a Curie temperature TC of about 270 K, which can be raised above room temperature by tuning the Fe deficiency content. To achieve insights into its ferromagnetic exchange, we have studied the critical behavior by measuring the magnetization in bulk Fe5GeTe2 crystal around the ferromagnetic to paramagnetic phase transition. The analysis of the magnetization by employing various techniques including the modified Arrott plot, Kouvel-Fisher plot and critical isotherm analysis achieved a set of reliable critical exponents with TC = 273.7 K, beta = 0.3457, gamma = 1.40617, and delta = 5.021, suggesting a three-dimensional magnetic exchange with the distance decaying as J(r) ~ (r)$^-4.916, which is close to that of a three-dimensional Heisenberg model with long-range magnetic coupling., 22 pages, 2 tables, 6 figures

Some dynamics behaviors for the nonautonomous stochastic fifth-order Swift–Hohenberg equation with additive white noise are considered. The existence of pullback random attractors for the nonautonomous stochastic fifth-order Swift–Hohenberg equation with some properties is mainly investigated on the bounded domain and unbounded domain, through the Ornstein–Uhlenbeck transformation and tail-term estimates. Furthermore, on the basis of some conditions, the finiteness of fractal dimension of random attractor is proved.

The antiferromagnet Mn${}_{3}$Ge has been recently shown to exhibit a large spontaneous anomalous Hall effect, which can be switched by a small magnetic field and which has been attributed to topologically protected Weyl nodes. Up till now, the true ground-state magnetic structure of the compound has eluded countless experimental studies, which began some fifty years ago. Here, the authors report the use of an advanced polarized neutron scattering technique to resolve unambiguously the magnetic structure of this compound.

We report on the structural, magnetic, and electronic properties of two new double-perovskites synthesized under high pressure; Pb2CaOsO6 and Pb2ZnOsO6. Upon cooling below 80 K, Pb2CaOsO6 simultaneously undergoes a metal--insulator transition and develops antiferromagnetic order. Pb2ZnOsO6, on the other hand, remains a paramagnetic metal down to 2 K. The key difference between the two compounds lies in their crystal structure. The Os atoms in Pb2ZnOsO6 are arranged on an approximately face-centred cubic lattice with strong antiferromagnetic nearest-neighbor exchange couplings. The geometrical frustration inherent to this lattice prevents magnetic order from forming down to the lowest temperatures. In contrast, the unit cell of Pb2CaOsO6 is heavily distorted up to at least 500 K, including antiferroelectric-like displacements of the Pb and O atoms despite metallic conductivity above 80 K. This distortion relieves the magnetic frustration, facilitating magnetic order which in turn drives the metal--insulator transition. Our results suggest that the phase transition in Pb2CaOsO6 is spin-driven, and could be a rare example of a Slater transition., Comment: 14 pages, 9 figures. Accepted as a regular article in Phys. Rev. B

The solutions of phenol and the mixture of phenol and ammonia were gasified in a continuous supercritical water reactor to evaluate the influences of ammonia on the hydrogen production and the degradation pathways of phenol. The effects of temperature (560–640 °C), reaction time (2–20 s) and concentration of ammonia (500–2000 mg/L) on gaseous distributions, gasification efficiencies and reactants removal efficiencies were investigated. In addition, the effects of ammonia on the kinds of intermediate products were analyzed. Results showed that the increasing temperature greatly promoted the hydrogen production and degradation of phenol. Longer reaction time gave a positive effect on gasification efficiencies in 10 s, while the effect was little when the reaction time longer than 10 s. Ammonia prevented the production of hydrogen and the degradation of phenol, which was mainly due to the generation of more stable nitrogen polycyclic compounds. The possible degradation pathways for the mixture of phenol and ammonia were proposed.

We report the synthesis of Na1-xCaxIrO3 (x = 0–1) at 3 GPa and 900 °C by using the high-pressure technique. Structure analysis indicates that all samples characterize in the post-perovskite (Ppv) structure. Physical properties characterizations reveal that Na1-xCaxIrO3 shows an insulator-metal transition (IMT) at x ≤ 0.1, and then exhibits a metal-insulator transition (MIT) with further increasing the Ca concentration to a level between x = 0.6 and 0.7. The transitions are associated with a gradual alternation of the paramagnetic ground state to an antiferromagnetic one due to the increase of Ir4+ ions (S = 1/2, t2g5) in the nonmagnetic Ir5+ (S = 0, t2g4) host. The IMIT are discussed by involving the delicate interactions in 5d oxides such as the spin-orbit coupling (SOC), electronic correlation, width of the 5d t2g band, and the crystal-field splitting energy within the t2g shell. The observation not only would be instructive for inducing novel electronic states via tuning the delicate interactions in 5d oxides but also might pave a way for studying the continuous crossover of a band insulator to a Mott insulator.

We investigated the magnetic structure and dynamics of YbMnBi$_2$, with elastic and inelastic neutron scattering, to shed light on the topological nature of the charge carriers in the antiferromagnetic phase. We confirm C-type antiferromagnetic ordering of the Mn spins below $T_{\rm N} = 290$ K, and determine that the spins point along the $c$-axis to within about $3^\circ$. The observed magnon spectrum can be described very well by the same effective spin Hamiltonian as was used previously to model the magnon spectrum of CaMnBi$_2$. Our results show conclusively that the creation of Weyl nodes in YbMnBi$_2$ by the time-reversal-symmetry breaking mechanism can be excluded in the bulk.