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<jats:p>The effect of strain on charge density wave (CDW) order in <jats:italic>α</jats:italic>-U is investigated within the framework of relativistic density-functional theory. The energetical stability of <jats:italic>α</jats:italic>-U with CDW distortion is enhanced by the tensile strain along <jats:italic>a</jats:italic> and <jats:italic>b</jats:italic> axes, which is similar to the case of negative pressure and normal. However, the tensile strain along <jats:italic>c</jats:italic> axis suppresses the energetical stability of CDW phase. This abnormal effect could be understood from the emergence of a new one-dimensional atomic chain along <jats:italic>c</jats:italic> axis in <jats:italic>α</jats:italic>-U. Furthermore, this effect is supported by the calculations of Fermi surface and phonon mode, in which the topological objects and the dynamical instability show opposite behaviors between strains along <jats:italic>a</jats:italic>/<jats:italic>b</jats:italic> and <jats:italic>c</jats:italic> axes.</jats:p>

<jats:p>The recent discovery of room temperature superconductivity (283 K) in carbonaceous sulfur hydride (C–S–H) has attracted much interest in ternary hydrogen rich materials. In this report, ternary hydride P–S–H was synthesized through a photothermal-chemical reaction from elemental sulfur (S), phosphorus (P) and molecular hydrogen (H<jats:sub>2</jats:sub>) at high pressures and room temperature. Raman spectroscopy under pressure shows that H<jats:sub>2</jats:sub>S and PH<jats:sub>3</jats:sub> compounds are synthesized after laser heating at 0.9 GPa, and a ternary van der Waals compound P–S–H is synthesized with further compression to 4.6 GPa. The P–S–H compound is probably a mixed alloy of PH<jats:sub>3</jats:sub> and (H<jats:sub>2</jats:sub>S)<jats:sub>2</jats:sub>H<jats:sub>2</jats:sub> with a guest–host structure similar to the C–S–H system. The ternary hydride can persist up to 35.6 GPa at least and shows two phase transitions at approximately 23.6 GPa and 32.8 GPa, respectively.</jats:p>

<jats:p>The magnetic and magnetocaloric properties were studied in a stuffed honeycomb polycrystalline antiferromagnet GdInO<jats:sub>3</jats:sub>. The onset temperature of antiferromagnetic ordering was observed at ∼ 2.1 K. Negligible thermal and magnetic hystereses suggest a reversible magnetocaloric effect (MCE) in the GdInO<jats:sub>3</jats:sub> compound. In the magnetic field changes of 0 kOe–50 kOe and 0 kOe–70 kOe, the maximum magnetic entropy change values are 9.65 J/kg⋅K and 18.37 J/kg⋅K, respectively, near the liquid helium temperature, with the corresponding relative cooling power values of 115.01 J/kg and 211.31 J/kg. The MCE investigation of the polycrystalline GdInO<jats:sub>3</jats:sub> serves to illuminate more exotic properties in this frustrated stuffed honeycomb magnetic system.</jats:p>

<jats:p>The degradation mechanism of GaN-based near-ultraviolet (NUV, 320–400 nm) light emitting diodes (LEDs) with low-indium content under electrical stress is studied from the aspect of defects. A decrease in the optical power and an increase in the leakage current are observed after electrical stress. The defect behaviors are characterized using deep level transient spectroscopy (DLTS) measurement under different filling pulse widths. After stress, the concentration of defects with the energy level of 0.47–0.56 eV increases, accompanied by decrease in the concentration of 0.72–0.84 eV defects. Combing the defect energy level with the increased yellow luminescence in photoluminescence spectra, the device degradation can be attributed to the activation of the gallium vacancy and oxygen related complex defect along dislocation, which was previously passivated with hydrogen. This study reveals the evolution process of defects under electrical stress and their spatial location, laying a foundation for manufacture of GaN-based NUV LEDs with high reliability.</jats:p>

<jats:p>We present a convenient and practical electromagnetic (EM) assisted small-signal model extraction method for InP double-heterojunction bipolar transistors (DHBTs). Parasitic parameters of pad and electrode fingers are extracted by means of 3D EM simulation. The simulations with a new excitation scheme are closer to the actual on-wafer measurement conditions. Appropriate simulation settings are calibrated by comparing measurement and simulation of OPEN and SHORT structures. A simpler <jats:italic>π</jats:italic>-type topology is proposed for the intrinsic model, in which the base-collector resistance <jats:italic>R<jats:sub>μ</jats:sub> </jats:italic>, output resistance <jats:italic>R</jats:italic> <jats:sub>ce</jats:sub> are deleted, and a capacitance <jats:italic>C</jats:italic> <jats:sub>ce</jats:sub> is introduced to characterize the capacitive parasitic caused by the collector finger and emitter ground bar. The intrinsic parameters are all extracted by exact equations that are derived from rigorous mathematics. The method is characterized by its ease of implementation and the explicit physical meaning of extraction procedure. Experimental validations are performed at four biases for three InGaAs/InP HBT devices with 0.8 × 7 μm, 0.8 × 10 μm and 0.8 × 15 μm emitter, and quite good fitting results are obtained in the range of 0.1–50 GHz.</jats:p>

<jats:p>The etching and passivation processes of very long wavelength infrared (VLWIR) detector based on the InAs/GaSb/AlSb type-II superlattice have been studied. By studying the effect of each component in the citric acid solution (citric acid, phosphoric acid, hydrogen peroxide, deionized water), the best solution ratio is obtained. After comparing different passivation materials such as sulfide + SiO<jats:sub>2</jats:sub>, Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> and SU8, it is found that SU8 passivation can reduce the dark current of the device to a greater degree. Combining this wet etching and SU8 passivation, the <jats:italic>R</jats:italic> <jats:sub>0</jats:sub> <jats:italic>A</jats:italic> of VLWIR detector with a mesa diameter of 500 μm is about 3.6 Ω⋅cm<jats:sup>2</jats:sup> at 77 K.</jats:p>

<jats:p>Research in the spintronics community has been intensively stimulated by the proposal of the spin field-effect transistor (SFET), which has the potential for combining the data storage and process in a single device. Here we report the spin dependent transport on a Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub>/GaAs based lateral structured device. Parallel and antiparallel states of two Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> electrodes are achieved. A clear MR loop shows the perfect butterfly shape at room temperature, of which the intensity decreases with the reducing current, showing the strong bias dependence. Understanding the spin-dependent transport properties in this architecture has strong implication in further development of the spintronic devices for room-temperature SFETs.</jats:p>

<jats:p>The physical processes occurring at open Na<jats:sup>+</jats:sup> channels in neural fibers are essential for the understanding of the nature of neural signals and the mechanism by which the signals are generated and transmitted along nerves. However, there is a less generally accepted description of these physical processes. We studied changes in the transmembrane ionic flux and the resulting two types of electromagnetic signals by simulating the Na<jats:sup>+</jats:sup> transport across a bionic nanochannel model simplified from voltage-gated Na<jats:sup>+</jats:sup> channels. The results show that the Na<jats:sup>+</jats:sup> flux can reach a steady state in approximately 10 ns due to the dynamic equilibrium of the Na<jats:sup>+</jats:sup> ion concentration difference between both sides of the membrane. After characterizing the spectrum and transmission of these two electromagnetic signals, the low-frequency transmembrane electric field is regarded as the physical quantity transmitting in the waveguide-like lipid dielectric layer and triggering the neighboring voltage-gated channels. Factors influencing the Na<jats:sup>+</jats:sup> flux transport are also studied. The impact of the Na<jats:sup>+</jats:sup> concentration gradient is found to be higher than that of the initial transmembrane potential on the Na<jats:sup>+</jats:sup> transport rate, and introducing the surface-negative charge in the upper third channel could increase the transmembrane Na<jats:sup>+</jats:sup> current. This work can be further studied by improving the simulation model; however, the current work helps to better understand the electrical functions of voltage-gated ion channels in neural systems.</jats:p>

<jats:p>In real-world networks, there usually exist a small set of nodes that play an important role in the structure and function of networks. Those vital nodes can influence most of other nodes in the network via a spreading process. While most of the existing works focused on vital nodes that can maximize the spreading size in the final stage, which we call final influencers, recent work proposed the idea of fast influencers, which emphasizes nodes’ spreading capacity at the early stage. Despite the recent surge of efforts in identifying these two types of influencers in networks, there remained limited research on untangling the differences between the fast influencers and final influencers. In this paper, we firstly distinguish the two types of influencers: fast-only influencers and final-only influencers. The former is defined as individuals who can achieve a high spreading effect at the early stage but lose their superiority in the final stage, and the latter are those individuals that fail to exhibit a prominent spreading performance at the early stage but influence a large fraction of nodes at the final stage. Further experiments are based on eight empirical datasets, and we reveal the key differences between the two types of influencers concerning their spreading capacity and the local structures. We also analyze how network degree assortativity influences the fraction of the proposed two types of influencers. The results demonstrate that with the increase of degree assortativity, the fraction of the fast-only influencers decreases, which indicates that more fast influencers tend to keep their superiority at the final stage. Our study provides insights into the differences and evolution of different types of influencers and has important implications for various empirical applications, such as advertisement marketing and epidemic suppressing.</jats:p>

<jats:p>Limited contact capacity and heterogeneous adoption thresholds have been proven to be two essential characteristics of individuals in natural complex social systems, and their impacts on social contagions exhibit complex nature. With this in mind, a heterogeneous contact-limited threshold model is proposed, which adopts one of four threshold distributions, namely Gaussian distribution, log-normal distribution, exponential distribution and power-law distribution. The heterogeneous edge-based compartmental theory is developed for theoretical analysis, and the calculation methods of the final adoption size and outbreak threshold are given theoretically. Many numerical simulations are performed on the Erdös–Rényi and scale-free networks to study the impact of different forms of the threshold distribution on hierarchical spreading process, the final adoption size, the outbreak threshold and the phase transition in contact-limited propagation networks. We find that the spreading process of social contagions is divided into three distinct stages. Moreover, different threshold distributions cause different spreading processes, especially for some threshold distributions, there is a change from a discontinuous first-order phase transition to a continuous second-order phase transition. Further, we find that changing the standard deviation of different threshold distributions will cause the final adoption size and outbreak threshold to change, and finally tend to be stable with the increase of standard deviation.</jats:p>