다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Half-Heusler (HH) compounds are among the most promising thermoelectric (TE) materials for large-scale applications due to their superior properties such as high power factor, excellent mechanical and thermal reliability, and non-toxicity. Their only drawback is the remaining-high lattice thermal conductivity. Various mechanisms were reported with claimed effectiveness to enhance the phonon scattering of HH compounds including grain-boundary scattering, phase separation, and electron–phonon interaction. In this work, however, we show that point-defect scattering has been the dominant mechanism for phonon scattering other than the intrinsic phonon–phonon interaction for ZrCoSb and possibly many other HH compounds. Induced by the charge-compensation effect, the formation of Co/4d Frenkel point defects is responsible for the drastic reduction of lattice thermal conductivity in ZrCoSb1−xSnx. Our work systematically depicts the phonon scattering profile of HH compounds and illuminates subsequent material optimizations.

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Unveiling the phonon scattering mechanisms in half-Heusler thermoelectric compounds

In the present work, we investigate the electronic and elastic properties in equilibrium and under strain of the type-II Dirac semimetal ${\mathrm{NiTe}}_{2}$ using density functional theory Our results demonstrate the tunability of Dirac nodes' energy and momentum with strain and that it is possible to bring them closer to the Fermi level, while other metallic bands are suppressed We also derive a minimal 4-band effective model for the Dirac cones, which accounts for the aforementioned strain effects by means of lattice regularization, providing an inexpensive way for further theoretical investigations and easy comparison with experiments On an equal footing, we propose the static control of the electronic structure by intercalating alkali species into the van der Waals gap, resulting in the same effects obtained by strain engineering and removing the requirement of in situ strain Finally, evaluating the wave-function's symmetry evolution as the lattice is deformed, we discuss possible consequences, such as Liftshitz transitions and the coexistence of type-I and type-II Dirac cones, thus motivating future investigations

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Strain engineering the topological type-II Dirac semimetal NiTe 2

Enhanced thermoelectric performance in Ti(Fe, Co, Ni)Sb pseudo-ternary Half-Heusler alloys

Enhanced thermoelectric performance of nominal 19-electron half-Heusler compound NbCoSb with intrinsic Nb and Sb vacancies

Evidences for pressure-induced two-phase superconductivity and mixed structures of NiTe2 and NiTe in type-II Dirac semimetal NiTe2-x (x = 0.38 ± 0.09) single crystals

Impurity tracking enables synthesis of TiFe1-xNixSb half-Heusler compounds with high purity

Dual three-phase permanent magnet synchronous machine (DTPM) is an attractive choice for electromechanical actuator owing to its advantages of double redundancy, high power density and high reliability. However, the winding insulation is susceptible to the high thermal and mechanical stress, which will lead to the inter-turn short circuit faults (ITSCF) and poses threat to the safety of the machine system. Moreover, the ITSCF of DTPM is not only limited to single-phase, but also occurs between adjacent phases. Therefore, in this paper, the characteristics of single-phase and phase-to-phase ITSCFs are investigated and compared while the short-circuit contact resistance is considered. Firstly, a general mathematical model for single-phase and phase-to-phase ITSCFs are established, and the expressions of short circuit current (SCC) and output torque are derived. Then, the characteristics of flux density, back-EMF, SCC, fault phase current and output torque of the different fault models are compared by finite element analysis. It is demonstrated that when the contact resistance is not zero ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R<sub>f</sub></i> ≠0), the amplitude of SCC and the third harmonic content of fault phase current are inversely proportional to the contact resistance and proportional to the number of short-circuit turns. In addition, the amplitude of SCC, torque ripple and braking torque caused by a phase-to-phase ITSCF will be larger than those of the single-phase ITSCF under the same fault conditions, especially when the contact resistance is small. Finally, an experimental prototype is made and tested to validate these analyses. 

Analysis of Inter-turn Short Circuit Faults in Dual Three-Phase PMSM for Electromechanical Actuator

At present, the calculation of electric field near the corner tower of high voltage transmission line ignores the end effect of transmission line. However, in fact, the end effect of transmission line will affect the charge distribution on the transmission line calculation model. In view of this, this paper uses the charge simulation method to calculate the charge distribution of the high-voltage transmission line near the corner tower, and proposes to use the unilateral periodic boundary condition to eliminate the end effect of the transmission line, so as to improve the charge distribution on the transmission line calculation model. Compared with the existing electric field calculation methods around the corner tower, the results of the proposed method have a slight deviation, but the overall deviation is negligible, which verifies the existing electric field calculation methods near the corner tower. 

Electric field calculation near corner tower of high voltage transmission line using unilateral periodic boundary condition

In this paper, based on the correlation matrix, the fault detection method of controller is studied based on the fault diagnosis characteristics of environment control and life support system(ECLSS). Combined with the characteristics of actual system fault diagnosis, the reasons for the existence of the feedback loop are analyzed, the different diagnostic effects caused by voltage and current detection methods are compared, and the detection method of breaking the feedback loop by manual testing is proposed. Through modeling and analysis, complete design ideas and methods are provided for improving testability design of controller products, which can help guide Built-In-Test(BIT) design of controllers. 

K. Wang

Papers

Evidences for pressure-induced two-phase superconductivity and mixed structures of NiTe2 and NiTe in type-II Dirac semimetal NiTe2-x (x = 0.38 ± 0.09) single crystals

Impurity tracking enables synthesis of TiFe1-xNixSb half-Heusler compounds with high purity

Analysis of Inter-turn Short Circuit Faults in Dual Three-Phase PMSM for Electromechanical Actuator

Electric field calculation near corner tower of high voltage transmission line using unilateral periodic boundary condition

Research on a system controller fault detection method based on correlation matrix