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Realizing "Power to Syngas" by electrifying chemical reactors via induction heating is one of the key enabling technologies to decarbonize the chemical industry. Nevertheless, developing catalysts for the induction heating process that can simultaneously serve as magnetic susceptors under high-temperature conditions remains challenging. Herein, we formulate a A-site vacancy induced electronic engineering strategy and, accordingly, synthesize a series of LaFe 0.5 Al 0.5 O 3 perovskite catalysts with different amounts of La vacancies (V La) (LFAO, 1.5 M-LFAO, and 3 M-LFAO). In this way, we tune both the redox activity and the magnetocaloric effect (MCE) of perovskite and, for the first time, achieve induction heating methane partial oxidation coupled with CO 2 splitting for syngas production. Compared with the reported catalysts, the 3 M-LFAO had not only superior syngas and CO yields (101.84 L·kg cat −1/54.96 L kg cat −1) but also a great MCE (875 °C). Spectroscopic investigations and DFT calculations rationalize these observations and demonstrate that the V La cause a unique Fe4+–O2-–Fe3+ configuration in perovskite, accounting for an upshift of Fe 3d and O 2p band centers and therefore enhancing redox activity and MCE. This work deepens the understanding of the relationship between catalysis and MCE and unlocks the novel guidance to design induction heating chemical processes. [Display omitted] • A highly efficient bifunctional magnetocaloric catalyst was successfully obtained. • La vacancy induced electron engineering created an asymmetric Fe4+–O2-–Fe3+ motif. • The asymmetric motif displayed superior redox activity and magnetocaloric effect. • Superior syngas and CO yields (101.84 L·kg cat −1/54.96 L kg cat −1) were realized. • A high temperature (875 °C) under induction heating was achieved. [ABSTRACT FROM AUTHOR]

In this work, a ceria promoted Ni-based catalyst supported in mesoporous montmorillonite (MMT) was developed and evaluated in ethanol steam reforming. This Ni-Ce/MMT catalyst was synthesized by an ultrasound assisted cation exchange impregnation method and characterized by X-ray diffraction, N 2 adsorption–desorption, H 2 temperature-programmed reduction and transmission electron microscopy. TEM images of Ni-Ce/MMT presented that narrow Ni nanoparticles (av. 6.0 nm) were uniformly deposited within the mesoporous MMT support. This was attributed to the strong interaction between Ni and ceria and the confinement effect from the framework of MMT support. The catalytic activity and stability of Ni-Ce/MMT were studied in steam ethanol reforming and compared with Ni/MMT. The higher ethanol conversion and H 2 selectivity of Ni-Ce/MMT demonstrated the addition of ceria facilities the reaction of ethanol steam reforming. Additionally, the ethanol conversion was much more stable on Ni-Ce/MMT than on Ni/MMT during a long-term ethanol steam reforming reaction, illustrating that the catalyst deactivation was preferably suppressed with the help of ceria. In short, the Ni-Ce/MMT is a promising catalyst for ethanol steam reforming owing to the remarkable effect of ceria as well as the confinement effect of MMT support which can effectively suppress the Ni sintering and carbon deposition. [ABSTRACT FROM AUTHOR]

Abstract: The Cienega de Santa Clara in the Colorado River Delta, Mexico is a self-designed wetland system fed since 1977 by brackish groundwater diverted from the U.S. to Mexico. The vegetated upper portion of the Cienega provides habitat for endangered Yuma-Clappers rails and other marsh birds and fulfills other ecological functions. Outflow water pools in the Santa Clara Slough south of the Cienega and provides habitat for migratory shorebirds. Conditions in the Cienega and Santa Clara Slough could be altered by operation of the Yuma Desalting Plant (YDP), which will divert water from the Cienega and replace it with brine water resulting from the desalting process. Our objective was to integrate water budget components into models predicting the extent of the dominant vegetation (southern cattail, Typha domingensis Pers.) in the marsh and the area of the outflow pool below the marsh in response to different operating scenarios for the YDP. The models are intended to serve as tools for resource managers charged with maintaining this wetland complex. Unlike many wetland water budget models, this one explicitly takes into account salinity as a factor in the water budget. We modeled inflow rates ranging from 1 to 6m3 s−1 and inflow salinities ranging from 0 to 6gL−1 Total Dissolved Solids. The model indicates that if the inflow rate is reduced below the current 4–5m3 s−1 the vegetated area of the Cienega would decrease in proportion, as would the area of the outflow pool in the Santa Clara Slough. Increases in salinity will also reduce the vegetated area due to the low salt tolerance of T. domingensis. In winter about 90% of inflow water exits the Cienega into the Santa Clara Slough due to low evapotranspiration, and on an annual basis 70% of inflows exit into the Santa Clara Slough. These flushing flows maintain the salt balance in the Cienega. The Santa Clara Slough is periodically flushed by spring tides, making this a sustainable, open wetland system in its present state. [Copyright &y& Elsevier]

Abstract: In this paper, influence of void ratio on thermal performance of heat pipe receiver under microgravity is numerically simulated. Accordingly, mathematical model is set up. Numerical method is offered. The temperature field of Phase Change Material (PCM) canister is shown. Numerical results are compared with numerical ones of National Aeronautics and Space Administration (NASA). Numerical results show that the temperature gradient increases significantly and the utility ratio of PCM decreases obviously as void ratio increases. Void cavity influences the process of phase change greatly. PCM melts slowly during sunlight periods and freezes slowly during eclipse periods as void ratio increases. The thermal resistance of void cavity is much bigger than that of PCM canister wall. Void cavity prevents the heat transfer between PCM zone and canister wall. The temperature gradient of PCM zone is very significant with the effect of void cavity. So the thermal stress of heat pipe receiver may increase, and the lifetime may decrease as void ratio increases. [Copyright &y& Elsevier]

Abstract: New product development (NPD) is crucial for a company’s success in a competitive market. Meanwhile, NPD is a process associated with great complexity and high risk. To ensure its smooth operation, risks involved in an NPD process need to be analyzed in a proper way. In this paper, a novel method is proposed to generate a belief rule base (BRB), which is the basis of the Belief Rule-Base Inference Methodology using the Evidential Reasoning (RIMER). Due to its capability in dealing with complex reasoning problems under uncertainty, RIMER is then applied to assess customer perception risk (CPR) in an NPD process. To test and validate the method proposed in this paper, a case study of an “Interactive Doll” is conducted at the end of the paper. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a natural convection micro cooling system with a capillary microgroove evaporator is proposed. An experimental study on the characteristics of thermal resistance, pressure drop and heat transfer of the cooling system is carried out. Experimental results indicate that the liquid fill ratio has a significant influence on thermal resistance and heat transfer in the cooling system. Increasing system''s cooling capacity at higher input power depends on decreasing the thermal resistance between the outer surfaces of the condenser and ambient environment. Compared with a flat miniature heat pipe (FMHP) and a current fan-cooled radiator for CPU chip of Pentium IV, the present micro cooling system has a stronger heat dissipation capacity. Its best cooling performance at a surface temperature of heat source below 373 K reaches and the maximum heat transportation capacity is 131.8 W. The novel kind of cooling system is suitable for remote cooling of those electronic parts with micro size, high power and thermal sensitivity. [Copyright &y& Elsevier]

Abstract: In this paper, a new method is proposed to effectively lower the high temperature, smooth the thermal stress and reduce the thermal deformation of mirrors in high-power laser systems utilizing functionally graded materials (FGMs). Two kinds of laser source are discussed at the same time. One is the doughnut-shaped laser, and the other is the Gaussian-distributed laser. Numerical results from finite element analysis show that the thermal deformation of silicon and copper mirrors can be reduced by one order of magnitude, and the temperature rise is also lowered obviously by this means. The effects of slope regulation of the functions for representation of thermophysical and mechanical properties on thermal deformation of mirrors are discussed to meet the requirement of optimum design and manufacture of FGM mirrors for the future. [Copyright &y& Elsevier]

Abstract: Finite element analysis on the coupled thermoelastic behavior in an aluminum thin film is demonstrated using implicit Newmark algorithm. The generalized dynamic theory of thermoelasticity is applied to solve both the equation of motion and the energy equation. The results show that the ratio between the relaxation times τ 0 and τ 2 controls the transition of the temperature evolution and thermal deformation among over-diffusive, diffusive, wavelike and wavy behaviors of heat conduction in time domain. The abnormality of temperature evolution and thermal deformation for wavy heat conduction is discussed. The applicability of the exponential and Gaussian form for the dynamic thermal expansion is illustrated primarily. [Copyright &y& Elsevier]

Perovskite shows promising perspective in photoelectric and thermoelectric applications due to its mediate bandgap and low TC stemming from its intrinsic structure, i.e., organic-inorganic framework. While nanostructuring can reduce the thermal conductivity (TC) significantly which is important for the improvement of the corresponding thermoelectric performance, it is detrimental to the electrical and mechanical properties of materials, e.g., conductivity and strength. Nanotwinning has been proved to be an effective strategy to decouple the electrical and thermal properties, and improve the mechanical properties, and therefore it is one of the best candidates for the design of highly efficient thermoelectrics. Moreover, the introduction of nanotwinning can break the host structure of perovskite and regulate the proportions of liquid-convectional and solid-vibrational heat transport in some degree. Therefore, nanotwinning can be seen as an important method to face the challenge in the applications of perovskite in the field of thermoelectric conversion efficiency and thermal stability. Here, the multichannel heat transport in single-crystalline and twinned hybrid organic–inorganic halide perovskite is quantitatively characterized and compared by performing molecular dynamics simulations. Our results demonstrate that the solid-vibrational heat transport plays a dominant role in the whole thermal transport process even under high temperature, however, the contribution of convective term which is usually ignored in the previous studies also reaches to 20–30% of that of solid virial term. Furthermore, we notice that the convectional TC shows an unconventional temperature-independent trend and the cross term expresses a surprising negative TC. As for the twinned perovskite, it is surprising to find that the position of twin boundary plays an important role in controlling TC, i.e., the TC shows a first downward and then upward trend when the twin boundary is located at I atoms (I-model), while decreases when the center of twin is at Pb atoms (Pb-model). Moreover, the completely opposite trends of the TC-contributed ratios between convective and virial term have been found in the I- and Pb-model, respectively. Further, we also notice the TC contributed by fluid convective term is enhanced comparing with single-crystalline case and the cross term shows a much more significant negative TC, which results in the unexpected phenomenon that the total TC is even lower than that contributed by virial term. Our investigations provide a fundament understanding of the thermal transport properties of perovskite and propose the key mechanisms to guide the thermal management. The position of twin boundary plays an important role in controlling the multi-thermal transport procedures in hybrid organic–inorganic halide perovskite, and twinned perovskite also shows some unconventional thermal transport properties. [Display omitted] • Thermal conductivity (TC) of liquid-solid coupling term shows a surprising negative value. • TCs of perovskite with twin boundary located at I and Pb atoms express nonmonotonic and monotonic trends, respectively. • κ convection /κ virial of I- and Pb-model show opposite trends following with the variation of periodic length. • κ convection /κ virial of twinned perovskite is enhanced, which is in opposite to the conventional viewpoint. • The cross term of twinned perovskite shows a huger negative TC which results in the surprising fact that κ total <κ virial. [ABSTRACT FROM AUTHOR]

The reasonable recycling of demolition wastes has attracted worldwide attention. Methods need to be investigated to reuse the waste materials such as broken bricks. This study added waste brick powder into the styrene-butadiene rubber (SBR) as one kind of filler in place of traditional fillers such as carbon black and white carbon black. The collected red brick fragments were broken into powder and filled in SBR to strengthen its mechanical property. Silane coupling agent KH-550 was utilized to improve the binding force between filler and rubber. The tensile property, conductivity and shore hardness of the vulcanized rubber was achieved. Results showed that the tensile strength of vulcanized SBR increased from 2.5 MPa to 3.6 MPa with the increase of brick powder filled in rubber. The Shore hardness increased from 43 to 53, while the volume resistance of the vulcanized rubber barely changed, maintaining around 5 kΩ cm. The rubber filled with modified brick powder showed better mechanical property than the unmodified. Economic and environmental profit were also evaluated. By applying red brick powder to polymer system, the problem of disposing demolition garbage can be eased and the cost will be markedly decreased in manufacturing polymer products. Image 1050 • Waste brick powder can be reused as a filler in Styrene-butadiene rubber. • Modified brick powder has a better reinforcement property than the unmodified. • The Shore hardness of vulcanized SBR increases with increasing brick powder. • Economical cost can be saved sharply using brick powder as a filler in rubber. [ABSTRACT FROM AUTHOR]

Abstract By performing molecular dynamics, the thermal transport properties of seven type graphyne (GY) with different structures (nanosheet, nanotube and GY/graphene (GR) heterojunction) are investigated. It can be observed comparing with other six GY, the thermal conductivity (TC) of (14,14,14)-GY shows unexpectedly significant anisotropy, which is consistent with previous study in Phys. Chem. Chem. Phys. 2016, 18, 24210. This anisotropy is mainly due to the lower contribution of high-frequency and short-wavelength phonons weakened by armchair (14,14,14)-GY. Moreover, when GY is rolled up to GY nanotubes (NTs), it is interesting to discover TC of GYNT, especially (14,14,14)-GYNT, shows a diameter-dependent anisotropy. For large-diameter NT, the TC of zigzag model is higher, however, an opposite phenomenon is obtained with small-diameter model. This phenomenon can be explained by the relative alternation of phonon group velocity and phonon lifetime and the appearance of band gap with the change of diameter. At last, we also notice the GY/GR heterojunctions express much lower thermal resistance (TR) comparing with other carbon based heterojunctions, and the in-plane TR of GY/GR heterojunction is two orders of magnitude lower than that of out-of-plane TR. Further, the alternation of TR can be well explained by the coupling degree of different type phonons. Graphical abstract Comparing with other six type graphyne, the thermal conductivity of (14,14,14)-GY shows unexpected significant anisotropy. And the corresponding nanotube, i.e., (14,14,14)-GY NT, exhibits an interesting diameter-dependent anisotropic thermal conductivity. Image [ABSTRACT FROM AUTHOR]

In this work, La 1− x Ce x NiO 3 perovskite-type oxide derived catalysts were synthesized for hydrogen generation from acetic acid steam reforming process (AcSR), and the effect of Ce substitution was investigated. Various techniques were applied to characterize the properties of synthesized catalysts including X-ray diffraction (XRD), H 2 temperature-programmed reduction (TPR), H 2 chemisorption, transmission electron microscopy (TEM), N 2 adsorption-desorption, and thermogravimetric analysis (TGA). The characterization results demonstrated that the perovskite-type oxide derived catalysts possessed uniform Ni dispersion and small Ni particle size. The adding of Ce remarkably increased the metal support interaction, improved the coke resistance and enhanced the water gas shift reaction. The reactivity and stability tests were conducted in a fixed-bed reactor. The La 0.9 Ce 0.1 NiO 3 exhibited the best performance for AcSR with an average H 2 yield of 90%, an average acetic acid conversion of 95%, and an accumulated coke deposition of 11.8 wt% in a 30-h stability test. [ABSTRACT FROM AUTHOR]

An electrified reactor driven by renewable electricity, substituting conventionally fired reactors, will reduce CO 2 and provide a compact manner for hydrogen generation. Herein, we proposed a high-efficiency electrified reactor based on a high-temperature heat pipe (HTPR). The start-up of the HTPR powered by electricity was firstly evaluated, showing a start-up duration of 250 s and maintaining significant temperature uniformity of 96.7%. Then, the feasibility and performance of the HTPR were validated by experiments. The methane conversion and hydrogen mole fraction were 80.0% and 70.5% at a steam to carbon ratio of three, respectively. Finally, the reaction performance under different operating conditions was simulated. The methane conversion and the hydrogen mole fraction were attenuated with the increase in flow rate, and improving catalyst porosity is beneficial for the heat transfer between catalysts and gases. This study serves as a framework for designing an electrified reactor for endothermic reactions. • An electrified high temperature heat pipe reactor (HTPR) was proposed. • The HTPR shows high temperature uniformity about 96.7%. • The HTPR achieved methane conversion of 80% and hydrogen purity of 70.5%. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials have been widely developed due to their attractive properties. Here, by using density functional theory (DFT) calculations, for the first time, we explore potential applications of the novel XIS (X = Al, Ga, In) monolayer 2D materials on photocatalytic water splitting. A series of simulations were carried out to predict and study the structural, elastic, phononic, optical and electronic properties of 2D XIS materials. The results show that GaIS and InIS demonstrate low thermal conductivity. For optical properties, AlIS shows strong light absorption coefficients and refractive index only under ultraviolet (UV) light, while GaIS and InIS show stronger performance under both visible light and UV light with the band edge positions spanned the redox potential of water. The reasonable band positions and bandgaps make them promising photocatalysts for water splitting. This work reveals the potential applications of monolayer 2D XIS in thermal, electronic, and photocatalytic water splitting. • A series of stable 2D XIS (X = Al, Ga, In) materials are first reported theoretically. • 2D XIS exhibits high anisotropy in elastic, phononic and optical properties. • 2D GaIS and InIS show enhanced absorption in visible and UV light regions. • 2D XIS demonstrates the potential applications for photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

Electrical and thermal management in nanodevices by means of carbon nanotube is highly promising. One main challenge toward CNT-based nanoscale electrical and thermal management devices is the development of effective strategies for reducing the bundle–bundle interface resistance. Here we report a novel strategy, based on the densification of CNT bundles and the functionalization of inter-bundle interfaces for effectively enhanced interfacial electrical and thermal transport. The densification is realized by utilizing the local electrostatic cohesion; and the functionalization is realized by the interface-decorated functional groups. Experiments and theoretical analysis demonstrated obviously enhanced interfacial electrical and thermal conductance originates from: (1) local Coulomb electrostatic cohesion between CNT bundles due to surface-induced dipole moments. This effect can promote both electrical and thermal conductance nearly 2.8 times higher than non-functionalized counterpart. (2) Increased interfacial electron transport channels and thermal vibrations due to surface-decorated functional groups. This effect can bring about up to 75% and 95% improvement for thermal and electrical conductance, respectively. This study provides a new methodology for tunable operation of electrical and thermal properties at inter-bundle interfaces and guidance for design of CNT-based electrical and thermal management devices. [ABSTRACT FROM AUTHOR]

• Thermal transport across metal interfaces was measured at the non-equilibrium states. • The measured h ee of Au/Pt matches well with the predicted value by electronic DMM. • Oxide layer significantly hinder electron thermal transport across metal interfaces. Interfaces play a critical role in nanoscale thermal transport, and understanding thermal transport mechanisms across metal/metal interfaces at the non-equilibrium states is urgently needed for highly integrated electronic structures or devices. In this work, the electronic interfacial thermal conductance h ee of two metal interfaces, Au/Pt and Au/Al, was measured by time domain thermoreflectance (TDTR) at the non-equilibrium states and an extended two-temperature model was applied to well describe the interactions of electrons between the metal films. For the Au/Pt structure, the measured h ee is 4.4 ± 1.8 GWm−2K−1, which is consistent with the predicted value by the electronic diffuse mismatch model (DMM). While for the Au/Al structure, the measured h ee (0.13±0.05 GWm−2K−1) is an order of magnitude smaller than that of Au/Pt and the predicted value of the electronic DMM. The results indicate that even the extremely thin oxide layer at the Au/Al interface can significantly hinder the electron thermal transport across the metal interface. Overall, our findings contribute to revealing the non-equilibrium interfacial thermal transport mechanisms and pave the way for designing the highly integrated electronic devices. [ABSTRACT FROM AUTHOR]

To avoid the high flow frictional loss associated with conventional wire mesh Stirling regenerators, a micro-channel type stacked porous-sheets Stirling regenerator is investigated. An analytical solution is derived for the transient heat transfer characteristics of the fully developed reciprocating laminar flow under prescribed wall temperature profiles. The complex Nusselt number (Nu) is expressed as a function of kinetic Reynolds number (Re ω ) and Prandtl number (Pr). At low Re ω of less than 10, the real part of Nu has an almost constant value of 6.0, approximately equal to the known real-valued Nu for the fully developed unidirectional laminar flow under constant wall heat flux, while the imaginary part is negligible, thus “scaling effect” can be utilized to enhance heat transfer. At higher Re ω , both the real and imaginary parts of Nu increase with the increase of Re ω and Pr, and the phase shift between the temperature difference and the heat flux gradually increases and approaches 45°. Approximate analytical solutions are also deduced for the entrance region from the integral boundary layer equations in both cases of “Thermally developing flow” and “Simultaneously developing flow”. The heat transfer is enhanced in the entrance region and the local Nu in the flow direction approaches the corresponding values of fully developed flow. The analytical results are confirmed by dynamic mesh CFD results, and the obtained Nu∼ Re ω data and patterns generally agree with available analytical and experimental data from published literatures. Application of the analytical results to the design and optimization of Stirling regenerator are also shown. [ABSTRACT FROM AUTHOR]

Refrigerants are ubiquitous in modern society, indispensable for various applications ranging from air conditioners and refrigerators to spacecraft and hospitals. Improving predictive methodologies for designing and implementing novel fluids is therefore essential. This paper presents an integrated prediction model augmented by attention mechanism for the molecular weight, boiling point, critical temperature, and critical pressure of fluorine/chlorine - based refrigerants. The model employs molecular groups as molecular structure descriptors and utilizes a machine learning algorithm with attention mechanisms. The prediction accuracy is good (all R 2 > 0.9), far ahead of other methods, such as Lydersen, Joback, Klincewicz-Reid, Constantinou-Gani, and multilayer perceptron methods. Furthermore, to gain insights into the influence of group features on property prediction, an interpretable method known as Shapley Additive Explanation (SHAP) was employed. This method computes the contributions of group features, thus providing a deeper understanding of the relationship between molecular groups and thermophysical properties. The results verified that the proposed models effectively establish this relationship. • Machine learning-based method for predicting properties of refrigerants. • Attention mechanism makes machine learning model prediction better than other methods. • Interpretable method was employed to provide insights into the predictions. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new type of solar collector with a large integrated heat pipe is designed. [•] An analysis of heat transfer inside new collector is presented. [•] A simulation of the heat transfer model is conducted. [•] The new collector can contribute to the application of more solar energy. [Copyright &y& Elsevier]

• The interfacial thermal conductance of GaN/AlN is investigated by both MD simulations and Monte Carlo simulations based on first-principles calculations. • Interfacial phonon modes are the additional channels for interfacial thermal transport. • Modal temperature and wave-resolved spectral heat flux provide modal-level and frequency-level acknowledge. Interfacial thermal conductance (ITC) is of critical importance for GaN-based device performance. GaN/AlN is a key component in GaN-based devices. Therefore, systematically investigating the interfacial thermal transport between GaN and AlN is of great significance for the thermal management of GaN-based devices. The temperature dependence of ITC across GaN/AlN interfaces are investigated using nonequilibrium molecular dynamics (NEMD) and Monte Carlo simulations based on first-principles calculations. Interestingly, the calculated ITC is much larger than that of GaN/metal, GaN/Si and GaN/SiC. Structural similarity and interfacial phonon modes are used to reveal the underlying mechanism. Moreover, the modal temperature and wave-resolved spectral heat flux are calculated to understand the interfacial thermal nonequilibrium and the dominant thermal transport channel, respectively. This study explores the modal-level and frequency-level mechanisms for interfacial thermal transport between GaN and AlN, which provides effective understanding in thermal management of GaN-based devices. [ABSTRACT FROM AUTHOR]

Abstract: The pricing mechanism in a deregulated electricity market is consistently a critical issue to improve market operations. Along with the development of electricity market, large consumers may purchase electric power from generators directly. In this paper, with an effort to introduce McAfee’s second-price sealed auction mechanism into multi-unit electric power transaction between competitive generators and large consumers, an auction model is developed to decide electric power price between competitive generators and large consumers based on the inclusion of the transaction cost and power transmission cost in a wholesale electricity market. After the description of pricing rules in the deregulated power market, auction rules and transaction rules are discussed. In particular, auction rules can increase the probability that generators providing a large number of supply and large consumers with high demand win the auction. On the other hand, transaction rules can optimize the whole transmission cost and transaction cost under market equilibrium, and the whole system is dispatched to maximize social welfare. A numerical example with eight suppliers and eight large consumers is provided to illustrate the essential features of this method. [Copyright &y& Elsevier]

Abstract: An infrared thermoviewer is utilized to measure the temperature distribution of solid walls and vapor–liquid interfaces of micrometer scale groove, which is made of borosilicate glass. The infrared thermal images clearly show that the wall temperature of microgroove top is lower than the temperature of vapor–liquid interface. The results indicate that heat source position, tilt angle, working liquid and heat flux have significant influences on the temperature distribution of microgrooves surface. It is further demonstrated that the temperature field in the microgrooves severely depends on the distribution of liquid film in this heat sink. [ABSTRACT FROM AUTHOR]

• An improved MTLS combined with k-means clustering called KMTLS is proposed. • The outliers and random errors of all variables are considered by KMTLS. • KMTLS have great robustness for handling outliers without setting threshold. • Simulations and experiment confirm the validity of KMTLS method. Curve and surface reconstruction methods play an important role in many research and engineering fields. It is an imperative procedure to carry out surface reconstruction from measurement data in reverse engineering, which is complicated with the presence of outliers. To achieve better accuracy and robustness of reconstruction, an improved moving total least squares (MTLS) algorithm based on k-means clustering called a KMTLS method is proposed in this article. Based on MTLS, KMTLS adjusts the weight of discrete points within the support domain by adopting a two-step fitting procedure. Firstly, an ordinary least squares (OLS) method is adopted to obtain the pre-fitting result and calculate the residuals as the input of k-means clustering. In k-means clustering, abnormal nodes are classified into one cluster and a weight function based on clustering information is introduced to deal with these nodes. Secondly, based on the compact weight function in MTLS and the weight obtained in the pre-fitting procedure, a weighted total least squares method is conducted to determine the final estimated value. The process of detecting outliers is automatic without setting threshold artificially. The simulation and experiment show that KMTLS has great robustness and accuracy. [ABSTRACT FROM AUTHOR]

• The N-face GaN optical phonon branch is localized more strongly than Ga-face. • The interface phonon of GaN/Al x Ga 1- x N is significantly localized. • The interface phonon dispersion curve is elevated. • Lattice distortion leads to a drift of the interface phonon branch. The phonon transport processes within a few atomic layers near heterointerfaces play a crucial role in thermoelectric applications such as nitride-based high electron mobility transistors (HEMTs) and light-emitting diodes (LEDs). However, a systematic investigation of their localized transport characteristics remains unexplored. This article employs the Interfacial Phonons method based on first-principles calculations to extract interface phonon information for GaN/Al x Ga 1- x N heterostructures. Molecular dynamics simulations are utilized to compare the phonon behaviors between Ga-face and N-face GaN-based heterointerfaces. The research extensively investigates the dependence of interfacial thermal transport on the concentration of Al atoms under ordered substitutional doping and the strength of uniaxial compressive strain. The research revealed that both Ga-face and N-face GaN/Al x Ga 1- x N heterointerfaces exhibit phonon branch drift. The differences in charge distribution at the polar surfaces lead to varying degrees of Brillouin zone distortion. The vibrational modes of the atoms at the N-face GaN interface are more compact and localized than those of Ga-face GaN, resulting in a stronger degree of localization for the optical phonon branches. When varying the doping concentration of Al atoms, some phonon branches at the GaN interface appear outside the band structure of the intrinsic bulk and surface states, exhibiting strong localized characteristics. The introduction of Al atoms at the heterointerface induces additional phonon scattering, and the lattice vibration mismatch between Al and Ga atoms results in a non-uniform residual stress field at the interface, further enhancing phonon-interface scattering. Moderate compressive strain-induced lattice distortion promotes the overlapping of phonon modes at the interface, allowing some localized phonons to serve as interface transport modes. This optimization enhances phonon transport at the heterointerface. This research provides valuable insights into a comprehensive understanding of interfacial thermal transport in GaN-based semiconductors. Moreover, it offers useful theoretical guidance for thermal management through the manipulation of phonon wave properties. [ABSTRACT FROM AUTHOR]

• Ultra-low lattice thermal conductivity of BaAg 2 SnSe 4 with the inclusion of the temperature-induced phonon coherent resonance effect is firstly captured. • Coupled with particle-like and wave-like propagation of phonon excitations successfully resolve the discrepancy between the theoretical and experimental κ L. • The results unequivocally verify the authenticity of the two-channel transport phenomenon driven by temperature in the case of superior thermoelectric materials. Phonon heat transfer by thermoelectric modules undoubtedly plays a pivotal role for the future waste heat recovery and utilization. BaAg 2 SnSe 4 , a prototypical glasslike compound among quaternary non-centrosymmetric chalcogenides, demonstrates remarkable thermoelectric performance due to its exceptionally low lattice thermal conductivity (κ L). Even with a comprehensive grasp of the underlying cause behind ultra-low κ L and the subsequent heightened thermoelectric conversion efficiency, the temperature-dependent lattice dynamics and glass-like attributes governing κ L continue to pose unresolved questions. In this study, we investigate the phonon thermal transport properties of quaternary BaAg 2 SnSe 4 by incorporating the influence of phonon coherent resonance, thereby departing from the conventional Peierls's framework. Based on the temperature dependence of the interatomic force constants and coherences' contribution to total lattice thermal conductivity (κ L (C)), we intriguingly observe that the particle-like driven lattice thermal conductivity (κ L (P)) and κ L (C) have the quite significant and dominant role for describing ultralow phonon transport behaviors in the middle-high-temperature regions. Specially, enhanced phonon anharmonicity coupled with excited coherent phonons due to increasing temperature yields two close values, with 700 K values of 0.16 and 0.13 W/mK predicted for BaAg 2 SnSe 4 , respectively, accelerating its application in thermoelectric field. Furthermore, we also find that the off-diagonal terms of heat flux operators in κ L exist distinction for different phonons, with zero contribution modes exhibiting temperature-independent phonon coherence effect. Temperature response of the force constants tensors and coherent resonance proposed in our work can be employed as a powerful tool, which would substantially be expected to inspire a broad revisiting phonon transport study in various device applications, including advanced thermal barrier coatings and superior thermoelectrics. [Display omitted] [ABSTRACT FROM AUTHOR]

• For the first time, first-principles calculations are used to predict the lattice thermal conductivity of free-standing monolayer XS2 (X = mo and W) and monolayer XS2 supported on SiC (0001) and ZnO (0001) substrates. • The lattice thermal conductivity of monolayer XS2 supported on SiC (0001) and ZnO (0001) substrates show a significant decrease, and the decrease is even greater for the monolayer XS2 supported on ZnO (0001) substrates, reaching about 65–70 %. • The substrate drives softening of the acoustic branch, making the low-frequency phonon group velocity decrease and the three-phonon scattering enhance. • From the perspective of atomic bonding, the substrate breaks the symmetry of bonding of monolayer XS2, which leads to the increase of phonon anharmonicity and ultimately to a decrease in thermal conductivity of monolayer XS2. Thermoelectric materials have properties such as direct conversion of waste heat into electricity and environmental friendliness, which make them promising for renewable energy utilization, however, the lower conversion efficiency limits the large-scale application of thermoelectric materials. Monolayer transition metal dichalcogenides (TMDs) are candidates for thermoelectric materials due to their high power factor, but their higher thermal conductivity (TC) limits the further improvement of the figure of merit (ZT). Here, we employ first-principles calculations and solve the Boltzmann transport equation (BTE) to compare the lattice TC of free-standing monolayer XS 2 (X = Mo and W) and monolayer XS 2 supported on SiC (0001) and ZnO (0001) substrates. We find that the lattice TC of monolayer XS 2 supported on SiC (0001) and ZnO (0001) substrates are sharply reduced. Especially supported on the ZnO (0001) substrate, the lattice TC of XS 2 reduce by 65 %–70 %, which is expected to improve the thermoelectric properties of monolayer XS 2. In addition, we report the underlying cause of this significant reduction in TC. Firstly, the substrate drives softening of the acoustic branch, which leads to a decrease of phonon group velocity in the low-frequency and an enhancement of the three-phonon scattering. Then, the asymmetric bonding of XS 2 is induced by the substrates, which enhance phonon anharmonicity and reduce the phonon lifetime. Our results demonstrate that the lattice TC of monolayer XS 2 can be tuned by adjusting the substrate, which has certain reference values for the thermoelectric design of XS 2. SiC (0001) and ZnO (0001) substrates break the symmetry of the monolayer XS 2 (X = Mo and W) bonding, resulting in an increase in phonon anharmonicity, which reduces the contribution of the low-frequency acoustic branch of monolayer XS 2 to the thermal conductivity. [Display omitted] [ABSTRACT FROM AUTHOR]

• Optimize the thermosyphon loop thermal performance by controlling loop wettability. • Long-term effective hydrophilic and hydrophobic modification method was determined. • The optimum wall wettability under different filling ratios was clarified. • The optimized R loop is reduced by 6.9% to 53.5% under different filling ratios. The behavior of vapor-liquid two-phase transport within the riser of the two-phase thermosyphon loop significantly impacts the heat transfer process from the evaporation to the condensation, as well as the circulation velocity, thus playing a crucial role in the heat transfer performance. However, existing research has predominantly focused on optimizing the performance of the evaporator, overlooking the optimization of vapor-liquid two-phase flow patterns and transport characteristics within the loop. This paper aims to optimize the heat transfer performance of the two-phase thermosyphon loop by controlling the wall wettability of the loop. The strategy employed involves modifying the wettability of the riser to regulate the two-phase flow within the loop, while visualization techniques are utilized to investigate the influence of riser wettability on the vapor-liquid two-phase distribution and heat transfer performance of the two-phase thermosyphon loop. The findings reveal that the impact of wall wettability on flow behavior and heat transfer performance within the loop varies significantly with changes in the filling ratio. This paper sheds some light on the riser wettability of two-phase thermosyphon loops to optimize the thermal performance. [ABSTRACT FROM AUTHOR]

• Simultaneous measurement of surface profile and thickness of the film structure • Achieve high-accuracy phase of spectral signal with phase-shifting method • Profile reconstruction error rectified using line-by-line calibration method • Measurement noise immunity enhanced with single wavenumber method White-light dispersive interferometry (WLDI) is an instantaneous, high-resolution optical metrological technique for measuring precise and complicated surfaces. This method enables nondestructive inspection of transparent-film-structure devices that are widely used in semiconductor packaging. We propose in this paper to use a home-built WLDI system with line-by-line spectral calibration, phase-shifting algorithm, and single-wave-number method for high-accuracy, simultaneous measurements of surface profiles and film thickness. By calibrating the relationship between wave-number and pixel position on each line of a two-dimensional detector, the line-by-line calibration method improves the measurement accuracy by correcting the spectral distortion caused by the optical system. Moreover, the spectral signal phase is obtained by the phase-shifting algorithm instead of by the Fourier transform method. The single-wave-number method is applied to the computation process by introducing the fringe order, and the measurement result indicates that it enhances the system immunity to environmental noise. A 1.806-µm-high standard step and a 1052.2-nm-thick standard film are measured to verify the system performance and show that the system is highly accurate and reliable. [ABSTRACT FROM AUTHOR]

• The phase equilibria of natural gas hydrate in real marine sediments were determined. • The endothermic peak bottom was proved corresponding to the phase equilibrium point. • Moisture difference affected decomposition pressure via changing sediment salinity. • The sediment salinity and gas components should be considered in spot production. Marine natural gas hydrate production has become a hot topic in recent years. There is still a long way to achieve the commercial production of marine hydrate reservoirs. The purpose of this work is to investigate the natural gas hydrate decomposition characteristics in the real marine sediments obtained from the South China Sea. A high-pressure micro-differential scanning calorimeter was employed to study the thermodynamic properties of natural gas hydrates. The results indicated that the increase in gas pressure or sediment salinity decreased the ice melting temperature by changing the vapor pressure of water. In addition, the decrease in sediment moisture from 40% to 30% increased the decomposition pressure of hydrates by 4.4 MPa at 278 K of sea bottom temperature, due to the water absorption capacity of the sediments increases the actual salinity furtherly. The influence of mixed gases on the decomposition pressure of hydrates was also investigated. The findings of this work on the effects of salinity and gas components on the decomposition pressure are significant to the spot safety production of marine natural gas hydrate reservoirs. [ABSTRACT FROM AUTHOR]