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The dramatic tropical cyclone (TC) damages in coastal areas around the world have gained significant attention from asset owners, policy makers and engineers. The estimate of TC damage for a specific region of interest is informative of the preparedness and resilience of the area subjected to TC hazards, and thus should be conducted using a quantitative approach. A reasonable indicator of TC damage should incorporate not only the TC characteristics (e.g., intensity, frequency and duration) but also the vulnerability of the TC-prone areas. In this paper, a new indicator is proposed to measure the TC threat, which takes into account both the TC characteristics and the vulnerability of the area. The indicator has two forms: the first one considers the maximum wind speed only and the second incorporates the integrated wind speed profile. The historical damage scenarios along the US East Coast, as well as those in Hong Kong, China, are examined to demonstrate the applicability of the proposed indicator. Results show that the proposed indicator is capable of representing the impact of TC wind field profile on the TC damage costs. The proposed indicator could be further used to project the future TC damages for areas subjected to TC hazards.

The use of underground spaces is becoming increasingly important in this era of rapid urbanization and population growth. However, underground spaces are susceptible to water ingress, which may trigger the deterioration of their structural performance and reduce their serviceability. This highlights the importance of the proper design of lining structures with an emphasis on water penetration. This study develops a reliability-based approach to guide the design of lining structures used for underground spaces. The equivalent depth of water seepage is considered for a two-dimensional lining structure in the presence of the randomness and spatial correlation of the water seepage distribution. The probabilistic behavior of the equivalent seepage depth that is derived serves as the basis for reliability-based design of lining structures. A simple design criterion is developed. An example is presented to demonstrate the applicability of the proposed approach.

This paper proposes explicit approaches for time-dependent reliability assessment of aging structures, taking into account the correlation associated with the load process and that arising from the resistance deterioration process. For the load process, temporal correlation may arise due to the impacts of underlying common causes. With this regard, a closed-form solution is developed for structural reliability, which models the sequence of load effects as a Markov process. Furthermore, the resistance deterioration is by nature a non-increasing stochastic process with autocorrelation on the temporal scale. The Gamma process is used to describe the stochastic behaviour of resistance deterioration, based on which an explicit reliability method is derived. The proposed reliability methods are straightforward to implement and thus are promising to be adopted in practical engineering regarding the safety evaluation of aging structures. Illustrative examples are presented to demonstrate the accuracy and applicability of the proposed approaches.

The antiferromagnetic topological insulator has attracted lots of attention recently, as its intrinsic magnetism and topological property make it a potential material to realize the quantum anomalous Hall effect at relative high temperature. Until now, only MnBi2Te4 is predicted and grown successfully. The other MB2T4-family materials predicted (MB2T4: M = transition metal or rare earth element, B = Bi or Sb, T = Te, Se, or S) with not only antiferromagnetic topological property but also rich and exotic topological quantum states and dynamically stable (or metastable) structure have not been realized on experiment completely. Here, MnBi2Te4 single crystals have been grown successfully by us. It shows typical antiferromagnetic character with Neel temperature of 24.5 K and a spin-flop transition at H ≈ 35,000 Oe, 1.8 K. In order to obtain the other members of MB2T4-family materials, it is necessary to understand the growth mode of MnBi2Te4. Its growth mode may be the layer-inserting growth mode based on symmetry, which is supported by our X-ray photoelectron spectroscopy (XPS) result, as the intrinsic chemical states of Mn and Te of MnBi2Te4 are the same with those of inserting material α-MnTe. Understanding the growth mode of MnBi2Te4 can help us to grow the other members of MB2T4-family materials.

The development of photosensitive slurries for additive manufacturing has attracted great interest due to their correlation with the final properties of the fabricated parts. This paper focus on the printing quality control in digital light processing (DLP) 3D printing of advanced ceramics. Systematic experiments were performed to assess the effects of the exposure time and printing angle on the three-point bending strength of the fabricated samples. The exposure time affected the bending strength of the printed zirconia ceramic dramatically. When the weak exposure time is 1 s and the strong exposure time is 13 s, the average bending strength can reach 580 MPa while Weibull modulus can reach 8.84. Meanwhile, the printing angle also affected the bending strength mechanical sample printed at 45° exhibits the worst performance.

Solid Oxide Fuel Cells (SOFCs) are environmentally efficient energy conversion devices, but are partially limited by the complicated fabrication procedure. In this work, dense 8 mol% yttria-stabilized zirconia (8YSZ) ceramics were successfully realized through a DLP (digital light processing) stereolithography method and the electrolyte self-supported fuel cell was also tested at 800 °C. The sintering behavior of the as-printed planar samples were investigated and a fully dense ceramic can be achieved at 1450 °C. The total conductivity of the sintered 8YSZ can reach 2.18 × 10−2 S cm−1 at a test temperature of 800 °C, which is acceptable for practical application. For the electrolyte self-supported fuel cell test, a power density of 114.3 mW cm−2 can be achieved when Ni-8YSZ cermet and La0.8Sr0.2MnO3 (LSM) were used as anode and cathode. It was demonstrated that 3D printing is a promising processing technique to build up electrolyte self-supported SOFCs with desired structure for the future development.

We have synthesized a new series of layered oxyselenides La2O3(Mn1−xCox)2Se2 through a solid state reaction method. Their structure and physical properties were studied through powder X-ray diffraction, electric transport measurements, absorption spectroscopy, bulk magnetization and specific heat experiments. These compounds crystallize in layered structures with the space group I4/mmm. All the samples present semiconducting or insulating behavior with the activation energy ranging from 0.134 eV to 0.400 eV. The ferromagnetic (FM) component is induced as Co enters the lattice, and the FM component raises to its maximum when x is 0.6. The competing of FM and antiferromagnetic (AFM) components led to the emergence of a spin-glass like behavior in the intermediate alloys.

The Pb39Bi25Sn36 alloy was directionally solidified at varied withdrawal rates followed by quenching. From metallographic observation, composition analysis and differential scanning calorimetry (DSC) analysis, the solidification sequence of Pb39Bi25Sn36 alloy was characterized. The Sn-dendrite is observed as the primary phase during solidification, followed by the β(Pb7 Bi3 )/Sn divorced eutectic. At lower temperatures, the β(Pb7Bi3 )/Sn binary eutectic is formed in the interdendritic region. However, the quasi-peritectic reaction [L+α-Pb→β(Pb7 Bi3 )+Sn] does not occur as the prediction based on ternary phase diagram analysis, which can be attributed to the unequilibrium solidfication condition. Moreover, the as-cast microstructure is significantly refined with the increasing withdrawal rates. The quenched sample only exhibits the lamellar structure of Sn, β(Pb7Bi3) and Bi phases. The results can provide instructions to optimize the as-cast microstructure of ternary alloys with quasi-peritectic reaction.

We report the superconductivity of a new quaternary compound ThMo$_2$Si$_2$C, synthesized with the arc-melting technique. The compound crystallizes in a tetragonal CeCr$_2$Si$_2$C-type structure with cell parameters of $a$ = 4.2296 \r{A}and $c$ = 5.3571 \r{A}. An interlayer Si-Si covalent bonding is suggested by the atomic distance. The electrical resistivity and magnetic susceptibility measurements indicate a Pauli-paramagnetic metal with dominant electron-electron scattering in the normal-state. Bulk superconductivity at 2.2 K is demonstrated with a dimensionless specific-heat jump of ${\Delta}C/\gamma_{\rm n}T$ = 0.98. The superconducting parameters of the critical magnetic fields, coherence length, penetration depth, and superconducting energy gap are given., Comment: 14 pages, 6 figures, 3 tables. Accepted for publication in SCIENCE CHINA Physics, Mechanics & Astronomy

Active immunization is a crucial colony-level pathogen defense to improve the survival of eusocial termites, which limits the lethal effect of biopesticides for termite control. Here, we report a possible strategy for RNAi-mediated metabolic disorders, which causes reduction in insect pathogen defense and might facilitate the foundation of nontoxic and sustainable pest control methods. Isocitrate dehydrogenase (IDH) was significantly upregulated by active immunization in termites, but its regulatory mechanism has yet to be well understood. We found that dsIDH-injected termites exhibited significantly reduced IDH at mRNA and protein levels and altered levels of isocitrate and NADH, indicating the impaired NAD+-IDH reaction. IDH-silenced termites displayed metabolic disorders, which was implied by significant changes in several metabolites from the carbohydrates and amino acids. When grooming toward fungus-exposed termites, IDH-silenced nestmates showed a significant upregulation of four apoptosis-related genes and caspase 3 activity, and hence the significantly increased rate of apoptosis. These physiological changes led to more apoptotic cell death in different body parts of the nestmates. In particular, more apoptotic cells increased disease susceptibility of the nestmates as revealed by growth of the significantly increased number of colony-forming units from dissected gut contents. Furthermore, the IDH-silenced nestmates exhibited lower antifungal activity and higher mortality, suggesting that IDH downregulation disrupted active immunization against fungal pathogens in termites. These findings illustrated the metabolic regulation of active immunization and provide a sound foundation for enhancing the impact of biopesticides by reducing the pathogen defense of hosts.

We collected in situ high-temperature powder X-ray diffraction (XRD) patterns, as well as Raman and Fourier transform infrared (FTIR) spectra on a natural serandite sample. The volumetric thermal expansion coefficient αV (K−1) is determined as a linear function of T (K): 37.6(5) × 10−9 × T + 11.1(3) × 10−6, with an averaged value of 31.7(10) × 10−6 K−1, while the anisotropy of axial thermal expansivities shows the order of αa > αb > αc. The isobaric Gruneisen parameters γiP are constrained as: 0.2–1.6 for most of the lattice vibrations below 500 cm−1; while 0–0.6 for the O–Si–O bending and Si–O stretching modes inside the Si3O9 chains above 500 cm−1. As compared with common silicate phases in the upper mantle and the transition zone, the γiP parameters for the internal vibrations are significantly smaller in silicate chains (serandite, enstatite) than those in Si2O7 groups (wadsleyite) and isolated SiO4 units (forsterite, pyrope), since the rotation of the bridging O atoms (in the direction perpendicular to Si–O–Si) could relax the SiO4 tetrahedra at elevated temperature. The OH-bending vibration of serandite is observed in both Raman-active (1378 cm−1) and IR-active (1389 cm−1) modes, with a temperature-dependence of − 0.07 and − 0.09 cm−1/K, respectively. The red-shift of these OH-bending modes with increasing temperature indicates that the hydrogen bond gets weaker as the O3…O4 distance becomes larger during thermal expansion. Additionally, our polarized FTIR spectra confirm that the stretching mode of the very strong hydrogen bond, a broad absorption region (1400–3300 cm−1), is polarized in the direction of E//b, as reported by Hammer et al. (Am Mineral 83:569–576, 1998).

The effect of powder characteristics on the thermal conductivity and mechanical properties of silicon nitride (Si 3 N 4 ) ceramics were investigated systematically by using two α-Si 3 N 4 powders a ...

We have synthesized a new series of layered oxyselenides Bi 2 LnO 4 Cu 2 Se 2 (Ln=Nd, Sm, Eu, Dy, Er, Yb). Their crystal structures and physical properties were studied through X-ray diffraction, electric transport measurements, bulk magnetization and first-principle calculation. All these compounds have a tetragonal structure with space group I4/mmm. They exhibit hole-type metallic behaviours which is also verified by the DFT calculation. The new Bi 2 LnO 4 -type block in these compounds may give people some enlightenment in synthesizing new iron-based superconductors or other layered compounds.

The trilayer nickelate ${\mathrm{Nd}}_{4}{\mathrm{Ni}}_{3}{\mathrm{O}}_{10\ensuremath{-}\ensuremath{\delta}}$ was investigated by the measurements of x-ray diffraction, electrical resistivity, magnetic susceptibility, and heat capacity. The crystal structure data suggest a higher Ni valence in the inner perovskitelike layer. At ambient pressure the resistivity shows a jump at 162 K, indicating a metal-to-metal transition (MMT). The MMT is also characterized by a magnetic susceptibility drop, a sharp specific-heat peak, and an isotropic lattice contraction. Below $\ensuremath{\sim}50\phantom{\rule{0.28em}{0ex}}\mathrm{K}$, a resistivity upturn with $logT$ dependence shows up, accompanied with negative thermal expansion. External hydrostatic pressure suppresses the resistivity jump progressively, coincident with the weakening of the $logT$ behavior. The low-temperature electronic specific-heat coefficient is extracted to be $\ensuremath{\sim}150\phantom{\rule{0.28em}{0ex}}\mathrm{mJ}\phantom{\rule{0.28em}{0ex}}{\mathrm{K}}^{\ensuremath{-}2}\phantom{\rule{0.16em}{0ex}}\mathrm{mol}\text{\ensuremath{-}}{\mathrm{f}.\mathrm{u}.}^{\ensuremath{-}1}$, equivalent to $\ensuremath{\sim}50\phantom{\rule{0.28em}{0ex}}\mathrm{mJ}\phantom{\rule{0.28em}{0ex}}{\mathrm{K}}^{\ensuremath{-}2}\phantom{\rule{0.16em}{0ex}}\mathrm{mol}\text{\ensuremath{-}}{\mathrm{Ni}}^{\ensuremath{-}1}$, indicating an unusual heavy-electron correlated state. The novel heavy-electron state as well as the logarithmic temperature dependence of resistivity is explained in terms of the ${\mathrm{Ni}}^{3+}$-centered Kondo effect in the inner layer of the ${({\mathrm{NdNiO}}_{3})}_{3}$ trilayers.

Tropical cyclones (TCs) are among the most costly natural hazards affecting civil construction in coastal areas, which have caused extensive economic losses and social disruption world-widely. Moreover, the intensity and/or frequency of future TCs have been projected to change with time due to the potential impacts of climate change, indicating the potential of ever larger TC damages for coastal regions. The estimate of future TC damage should be conducted under a probability-based framework, taking into account the uncertainties associated with both the TC characteristics (e.g., intensity and frequency) and the vulnerability of the coastal communities of interest. In this paper, an explicit approach is developed to evaluate the TC damage for TC-prone areas considering the potential impacts of climate change. The mean value and variance, as well as the cumulative density function of cumulative TC damage are estimated quantitatively. The proposed method is applied to TC damage assessment of Hong Kong, China – a TC-prone area which has suffered severely from historical cyclones. Sensitivity analysis is also performed to investigate the impacts of the time-variant characteristics of both the TC process and the TC damage conditional on one TC event on the cumulative damage costs for coastal areas.

Herein, Dy3+ doped indium nitride nanosheets with ferromagnetism at room-temperature were synthesized via a vapor - solid phase nitriding reaction. The as-synthesized samples exhibit clear ferromagnetism at room-temperature. The ferromagnetic properties of the samples could be changed by doped Dy3+. The saturation magnetization value of various Dy3+ doped indium nitride nanosheet samples display a parabolic-like change with the Dy3+ doped content increase and reaches the top value of 0.1455 emu g−1 corresponding to the Dy3+ doped content of 1.06 at. % at room temperature. The magnetic properties were originated from the d-f interaction between localized carriers and adjacent rare earth Dy3+ ions in the carrier orbits based on the first-principles calculation. The as-synthesized Dy doped indium nitride nanosheets can be widely used in spintronic devices due to the room temperature ferromagnetism.

The effect of heat treatment on the in-line transmittance of BaZr 0.5 Ce 0.3 Y 0.2 O 3−δ (BZCY532) ceramics prepared by spark plasma sintering method was investigated. The loss of Ba in transparent BZCY532 ceramics is the key reason for the loss of transmittance during the annealing process. This problem can be effectively alleviated by using a powder bed of BZCY532. Heat treatment atmospheres, wet air and dry air, were also found to be critical for obtaining high quality transparent ceramics. A highly transparent BZCY532 ceramic with the in-line transmittance (T in ) of 71.4% at 2000 nm can be obtained by using SPS method followed by an annealing in powder bed at 1500 °C in wet air.

For a magnetic confinement fusion device, the superconducting magnets and busbars need to be insulated with one layer of solid insulation to isolate the high voltage potential from the ground. The insulation layer commonly consists of several interleaved layers of epoxy resin-impregnated glass fiber tapes and polyimide films. The traditional electrical inspection methods for such solidified insulation on the magnet and busbar are a DC voltage test or a Paschen test. These tests measure the quality of the insulation based on the value of leakage currents. However, even if there is a larger quantity of high dielectric strength material implemented, if there are some microcavities or delaminations in the insulation system, the leakage current may be limited to microampere levels under testing levels over dozens of kilovolts. Therefore, it is difficult to judge the insulation quality just by the magnitudes of leakage current. Under long-term operation, such imperceptible defects will worsen and finally completely break down the insulation because of partial discharge (PD) incidents. Therefore, a PD detection test is an important complement to the DC voltage and Paschen tests for magnet and busbar insulations in the field of fusion. It is known that the PD detection test is a mature technique in the electric power industry. In this paper, the PD characteristics of samples containing glass fiber-reinforced composite insulations for use with the superconducting busbar were presented and discussed. Various samples with different void contents were prepared and the PD behaviors were tested.

Understanding the spatial structure of wind speed profile of a tropical cyclone (TC) is of critical importance to assess the TC-related damage and map the risk for afflicted areas. The wind field structure of a TC can be regarded as a horizontal primary circulation superimposed by a vertical–radial secondary convection driven by thermal balance. The gradient wind field model has been widely utilized in literature to describe the radial distribution of wind speed with respect to the TC center. In this paper, a new gradient wind field model is developed for translating TCs, based on the vector summation of the rotational wind speed and the translation speed. The accuracy and efficiency of the proposed model are demonstrated through comparing the wind fields generated from model solution and those recorded historically. The proposed model only involves simple algebra, which is beneficial for practical applications, especially in simulation-based studies of TC wind field modeling.

We report the results of X-ray diffraction and 57Fe Mossbauer spectroscopy study, complemented by ab-initio calculations of the electronic structure, hyperfine-interaction parameters, and elastic properties of the new 30 K superconductor ThFeAsN. The superconductor crystallizes in the tetragonal space group P4/nmm with the lattice parameters a = 4.0356(1) A and c = 8.5286(1) A. Contrary to the claims in the literature, we demonstrate unequivocally that there is no magnetic order of the Fe magnetic moments down to 2.0 K. It is suggested that the absence of Fe magnetism may be due to an internal uniaxial chemical pressure whose presence is manifested by the unusually small c/a ratio. Evidence is provided for the presence of a mixture of ionic and covalent chemical bonding and of metallic characteristics. A detailed analysis of the energy band structure of ThFeAsN is presented. The shape of the Mossbauer spectra is accounted for by a quadrupole doublet with a small quadrupole splitting that increases with decreasing temperature. Excellent agreement between the calculated and measured 0 K quadrupole splittings is observed. Fair agreement between the experimental Debye temperature of 332(2) K and the calculated one of 370 K is observed.

Natural hazards such as hurricanes may cause extensive economic losses and social disruption for civil structures and infrastructures in coastal areas, implying the importance of understanding the construction performance subjected to hurricanes and assessing the hurricane damages properly. The intensity and frequency of hurricanes have been reported to change with time due to the potential impact of climate change. In this paper, a probability-based model of hurricane damage assessment for coastal constructions is proposed taking into account the non-stationarity in hurricane intensity and frequency. The non-homogeneous Poisson process is employed to model the non-stationarity in hurricane occurrence while the non-stationarity in hurricane intensity is reflected by the time-variant statistical parameters (e.g., mean value and/or standard deviation), with which the mean value and variation of the cumulative hurricane damage are evaluated explicitly. The Miami-Dade County, Florida, USA, is chosen to illustrate the hurricane damage assessment method proposed in this paper. The role of non-stationarity in hurricane intensity and occurrence rate due to climate change in hurricane damage is investigated using some representative changing patterns of hurricane parameters.

The intensity and/or frequency of hurricane storms may change due to the impact of potential climate change. This paper presents a probabilistic framework to assess the hurricane damage to residential constructions considering the non-stationarity and correlation in hurricane actions. The framework includes a non-stationary Poisson process of hurricane occurrence, a failure rate function of hurricane damage, and explicit formulas for evaluating the mean and variance of annual hurricane damage. The framework is illustrated using a case study of Miami-Dade County, Florida, where the current probabilistic models of hurricane intensity and occurrence rate were estimated by examining hurricane history in this area. The impacts of time-variant hurricane intensity and time-variant hurricane frequency on building damage are assessed individually using the developed framework. The paper also investigates the effects of correlation in hurricane wind speeds on hurricane damage.

The relationship between the doping position of Nb in Bi2Se3 and its superconductivity is investigated by XPS, magnetic measurement and transport measurement. It is found that for NbxBi2Se3, the main impurity phase comes from BiNbSe3. Superconducting volume fraction of Nb doped Bi2Se3 increases with the ratio of Nb inserted in the van der Waals layers. The van der Waals-layer-position doped Nb may lead to superconductivity in Bi2Se3. This work may stimulate further investigation on topological superconductivity mechanism of NbxBi2Se3.

We investigated the physical properties of the cobalt doped layered oxyselenides BiCu1-xCoxSeO. 5% Co doping led to a large increase in the Seebeck coefficient which should be attributed to the magnetic interactions with the magnetic moment carried by Co atoms. The carrier-type of the material is changed from p-type to n-type with 20% Co doping. We studied the thermoelectric property of Bi0.95Ca0.05Cu0.95Co0.05SeO. The dual-doping sample exhibits higher Seebeck coefficient than Ca single doped sample and the ZT was enhanced remarkably. A maximum ZT value of 0.11 was achieved for Bi0.95Ca0.05Cu0.95Co0.05SeO at 300 K.

ThFeAsN$_{1-x}$O$_x$ ($0\leq x\leq0.6$) system with heavy electron doping has been studied by the measurements of X-ray diffraction, electrical resistivity, magnetic susceptibility and specific heat. The non-doped compound exhibits superconductivity at $T_\mathrm{c}^\mathrm{onset}=30$ K, which is possibly due to an internal uniaxial chemical pressure that is manifested by the extremely small value of As height with respect to the Fe plane. With the oxygen substitution, the $T_\mathrm{c}$ value decreases rapidly to below 2 K for $0.1\leq x\leq0.2$, and surprisingly, superconductivity re-appears in the range of $0.25\leq x\leq0.5$ with a maximum $T_\mathrm{c}^\mathrm{onset}$ of 17.5 K at $x=0.3$. For the normal-state resistivity, while the samples in intermediate non-superconducting interval exhibit Fermi liquid behavior, those in other regions show a non-Fermi-liquid behavior. The specific heat jump for the superconducting sample of $x=0.4$ is $\Delta C/(\gamma T_\mathrm{c})=0.89$, which is discussed in terms of anisotropic superconducting gap. The peculiar phase diagram in ThFeAsN$_{1-x}$O$_x$ presents additional ingredients for understanding the superconducting mechanism in iron-based superconductors., Comment: 10 pages, 7 figures

The recently synthesized ThFeAsN iron-pnictide superconductor exhibits a $T_c$ of 30 K, the highest of the 1111-type series in absence of chemical doping. To understand how pressure affects its electronic properties, we carried out microscopic investigations up to 3 GPa via magnetization, nuclear magnetic resonance, and muon-spin rotation experiments. The temperature dependence of the ${}^{75}$As Knight shift, the spin-lattice relaxation rates, and the magnetic penetration depth suggest a multi-band $s^{\pm}$-wave gap symmetry in the dirty limit, while the gap-to-$T_c$ ratio $\Delta/k_\mathrm{B}T_c$ hints at a strong-coupling scenario. Pressure modulates the geometrical parameters, thus reducing $T_c$, as well as $T_m$, the temperature where magnetic-relaxation rates are maximized, both at the same rate of approximately -1.1 K/GPa. This decrease of $T_c$ with pressure is consistent with band-structure calculations, which relate it to the deformation of the Fe 3$d_{z^2}$ orbitals., Comment: 6 pages, 4 figures

We have investigated the superconducting ground state of the newly discovered superconductor ThFeAsN with a tetragonal layered crystal structure using resistivity, magnetization, heat capacity, and transverse-field muon-spin rotation ($\mathrm{TF}\ensuremath{-}\ensuremath{\mu}\mathrm{SR}$) measurements. Our magnetization and heat-capacity measurements reveal an onset of bulk superconductivity with ${T}_{c}\ensuremath{\sim}30\phantom{\rule{0.28em}{0ex}}\mathrm{K}$. A nonlinear magnetic-field dependence of the specific heat coefficient $\ensuremath{\gamma}(H)$ has been found in the low-temperature limit, which indicates that there is a nodal energy gap. Our analysis of the $\mathrm{TF}\ensuremath{-}\ensuremath{\mu}\mathrm{SR}$ results shows that the temperature dependence of the superfluid density is better described by a two-gap model either isotropic $s+s$ wave or $s+d$ wave than a single-gap isotropic $s$-wave model for the superconducting gap, consistent with other Fe-based superconductors. The combination of $\ensuremath{\gamma}(H)$ and $\mathrm{TF}\ensuremath{-}\ensuremath{\mu}\mathrm{SR}$ results suggest that the ($s+d$)-wave model is the most consistent candidate for the gap structure of ThFeAsN. The observation of two gaps in ThFeAsN suggests a multiband nature of the superconductivity possibly arising from the $d$ bands of Fe ions. Furthermore, from our $\mathrm{TF}\ensuremath{-}\ensuremath{\mu}\mathrm{SR}$ study we have estimated the magnetic penetration depth in the polycrystalline sample of ${\ensuremath{\lambda}}_{L}(0)=375\phantom{\rule{0.28em}{0ex}}\mathrm{nm}$, superconducting carrier density ${n}_{s}=4.97\ifmmode\times\else\texttimes\fi{}{10}^{27}\phantom{\rule{0.28em}{0ex}}{\mathrm{m}}^{\ensuremath{-}3}$, and carrier's effective-mass ${m}^{*}=2.48{m}_{e}$. We compare the results of our present paper with those reported for the Fe-pnictide families of superconductors.

In this work, the TiO 2 -SrTiO 3 hybrids were synthesized by a facile hydrothermal reaction using TiO 2 as the titanium precursor under basic condition. By using the synthesized TiO 2 -SrTiO 3 hybrids as fillers, the films of the TiO 2 -SrTiO 3 /PVDF composites were prepared. The dielectric property and insulation behavior of the films were investigated. High permittivity and improved breakdown strength of the composites were achieved. The breakdown strength of the composites filled with 1 wt% hybrids exhibited an improvement about 80% compared with the unfilled PVDF matrix.

Relatively little attention has focused on how pesticides may affect Asian honey bees, which provide vital crop pollination services and are key native pollinators. We therefore studied the effects of a relatively new pesticide, flupyradifurone (FLU), which has been developed, in part, because it appears safer for honey bees than neonicotinoids. We tested the effects of FLU on Apis cerana olfactory learning in larvae (lower dose of 0.033 µg/larvae/day over 6 days) and, in a separate experiment, adults (lower dose of 0.066 µg/adult bee/day) at sublethal, field-realistic doses given over 3 days. A worst-case field-realistic dose is 0.44 µg/bee/day. Learning was tested in adult bees. The lower larval dose did not increase mortality, but the lower adult dose resulted in 20% mortality. The lower FLU doses decreased average olfactory learning by 74% (larval treatment) and 48% (adult treatment) and reduced average memory by 48% (larval treatment) and 22% (adult treatment) as compared to controls. FLU at higher doses resulted in similar learning impairments. The effects of FLU, a pesticide that is reported to be safer than neonicotinoids for honey bees, thus deserve greater attention.

We report neutron diffraction and transport results on the newly discovered superconducting nitride ThFeAsN with $T_c=$ 30 K. No magnetic transition, but a weak structural distortion around 160 K, is observed cooling from 300 K to 6 K. Analysis on the resistivity, Hall transport and crystal structure suggests this material behaves as an electron optimally doped pnictide superconductors due to extra electrons from nitrogen deficiency or oxygen occupancy at the nitrogen site, which together with the low arsenic height may enhance the electron itinerancy and reduce the electron correlations, thus suppress the static magnetic order., 4 pages, 4 figures, Accepted by EPL

We use neutron powder diffraction to study on the non-superconducting phases of ThFeAsN$_{1-x}$O$_x$ with $x=0.15, 0.6$. In our previous results on the superconducting phase ThFeAsN with $T_c=$ 30 K, no magnetic transition is observed by cooling down to 6 K, and possible oxygen occupancy at the nitrogen site is shown in the refinement(H. C. Mao \emph{et al.}, EPL, 117, 57005 (2017)). Here, in the oxygen doped system ThFeAsN$_{1-x}$O$_x$, two superconducting region ($0\leqslant x \leqslant 0.1$ and $0.25\leqslant x \leqslant 0.55$) have been identified by transport experiments (B. Z. Li \emph{et al.}, J. Phys.: Condens. Matter 30, 255602 (2018)). However, within the resolution of our neutron powder diffraction experiment, neither the intermediate doping $x=0.15$ nor the heavily overdoped compound $x= 0.6$ shows any magnetic order from 300 K to 4 K. Therefore, while it shares the common phenomenon of two superconducting domes as most of 1111-type iron-based superconductors, the magnetically ordered parent compound may not exist in this nitride family., Comment: 4 pages, 4 figures

We report the first nitrogen-containing iron-pnictide superconductor ThFeAsN, which is synthesized by a solid-state reaction in an evacuated container. The compound crystallizes in a ZrCuSiAs-type structure with the space group P4/nmm and lattice parameters a=4.0367(1) {\AA} and c=8.5262(2) {\AA} at 300 K. The electrical resistivity and dc magnetic susceptibility measurements indicate superconductivity at 30 K for the nominally undoped ThFeAsN., Comment: 6 pages, 4 figures, 1 table

Here we report effects of pressure on the recently discovered iron-based superconductor ThFeAsN, the first FeAs-based superconductor containing an actinide element, by in situ high-pressure resistance and synchrotron X-ray diffraction measurements. Our results show that the superconducting transition temperature (T C ) decreases monotonously with increasing pressure and then vanishes at 25.4 GPa. The analysis of the As anion height above the Fe layer ( ), as well as the bond angle of As-Fe-As (α ), for the pressurized ThFeAsN sample found that its T C vs. or α follows the same universal curve describing most of the iron-based superconductors. The results indicate that the lattice parameters also control the superconductivity of the ThFeAsN superconductor, similar to other FeAs-based superconductors, as long as the “superconducting gene” is a FeAs layer. Furthermore, we demonstrate that the ambient-pressure ThFeAsN is an “intrinsic” superconductor, while its lattice structure is not in the optimal state of the FeAs-based superconductors.

We report the synthesis and physical properties of a nickel-based arsenide ThNiAsN. The new compound crystallizes in a ZrCuSiAs-type structure (space group ) with lattice parameters and . Bulk superconductivity at is demonstrated by the measurements of electrical resistivity, dc magnetic susceptibility, and heat capacity. The upper critical field at zero temperature, , and the specific-heat jump at T c are 6.1 T and , respectively. These two physical quantities, together with the T c value, are the highest among the Ni-based ZrCuSiAs-type materials. We discuss this enhanced superconductivity in terms of the internal chemical pressure in ThNiAsN.