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Lattice vibrations or phonons play an important role in determining material properties, including thermal conductivity. To model the phenomenon accurately and efficiently, the most important factors governing phonon physics need to be identified, for example, polarization branches. Research continues into many aspects of the fundamental physical processes involved in phonons and into possible applications of these processes in modern physics. One of the most interesting controversies in the thermal properties of graphene involves the importance of out-of-plane acoustic phonons. The need for clarity in understanding this importance dictates that the thermal conductivity of graphene should be evaluated in various circumstances. The nanoscale heat conduction properties of graphene are studied by iteratively solving the Boltzmann transport equation and rigorously treating the normal and Umklapp collisions in the frame of three-phonon interactions. This captures the mechanistic aspects of thermal conductivity by revealing what phonon branches are present. The thermal conductivity is evaluated in different crystallite sizes and at different frequencies and temperatures. The results indicated that out-of-plane acoustic phonons become increasingly important in the frame of three-phonon interactions. The out-of-plane acoustic branch dominates thermal transport whereas the other acoustic branches make small contributions. The importance of this branch is generally attributed to the high density of states and restrictions governing anharmonic effects. The three-phonon normal and Umklapp processes must be clearly accounted for and the contribution from optical branches is not negligible at higher temperatures. The results have implications in the quest for predictive and quantitative calculations of thermal conductivity.

The band structure, density of state and absorption spectrum of Zn${}_{1-x}$Ag${}_x$O (x = 0.02778, 0.04167) were calculated. Results indicated that a higher doping content of Ag led to a higher total energy, lower stability, higher formation energy, narrower bandgap, more significant red shift of the absorption spectrum, higher relative concentration of free hole, smaller hole effective mass, lower mobility and better conductivity. Furthermore, four types of model with the same doping content of double Ag-doped Zn${}_{1-x}$Ag${}_x$O (x = 0.125) but different manners of doping were established. Two types of models with different doping contents of double Ag-doped Zn${}_{1-x}$Ag${}_x$O (x = 0.0626, 0.0833) but the same manner of doping, were also established. Under the same doping content and different ordering occupations in Ag double doping, the doped system almost caused magnetic quenching upon the nearest neighbor –Ag–O–Ag– bonding at the direction partial to the a- or b-axis. Upon the next-nearest neighbor of –Ag–O–Zn–O–Ag– bonding at the direction partial to the c-axis, the total magnetic moment of the doped system increased, and the doped system reached a Curie temperature above the room-temperature. All these results indicated that the magnetic moments of Ag double-doped ZnO systems decreased with increased Ag doping content. Within the range of the mole number of the doping content of 0.02778–0.04167, a greater Ag doping content led to a narrower bandgap of the doped system and a more significant red shift in the absorption spectrum. The absorption spectrum of the doped ZnO system with interstitial Ag also shows a red shift.

The structural, elastic, electronic and optical properties of two novel phases Si₃P₄ with tetragonal and orthorhombic structures are studied by first-principles calculations according to density function theory (DFT). For novel structures t-Si₃P₄ and o-Si₃P₄, the elastic constants results show that they are mechanically stable. The phonon dispersion spectra confirm that they are dynamically stable. The forming enthalpies prove their thermodynamic stability. The mechanical properties, such as the bulk modulus B, shear modulus G, Pugh ratio k, Young’s modulus E and Poisson’s ratios $\nu$ are calculated. The results show that t-Si₃P₄ has better anti-deformation ability than o-Si₃P₄, and t-Si₃P₄ is harder than o-Si₃P₄. The Poisson’s ratio values of t-Si₃P₄ and o-Si₃P₄ are 0.16 and 0.35, and the Pugh ratio values, k, are 0.88 and 0.33. For t-Si₃P₄, the Pugh ratio k$>$ 0.57 indicates that it behaves in a brittle manner. For o-Si₃P₄, it owns the better plasticity. The directional dependence of the Young’s modulus indicates that o-Si₃P₄ is more anisotropic than t-Si₃P₄. The calculated band structures show that the two novel phases are semiconductors, and the narrow indirect bandgaps are 1.847 and 0.158 eV by using PBE0. The densities of states (DOS) indicate that the P ‘p’ and Si ‘p’ play major roles in two phases total DOS. The results of the optical properties, such as the dielectric functions, absorption spectra, loss functions, refractive index, and so on are given. The static dielectric constants are 5.493 and 12.206, the starting positions of the absorption spectra are approximately at 1.815 and 0.140 eV, and the peaks of loss functions are at 15.503 and 11.763 eV, for t-Si₃P₄ and o-Si₃P₄, respectively.

In this study, ion-beam-sputtering technique is used to prepare nanocomposite films, consisting of deposited copper nanoparticles (CuNPs) on polyethyleneterephthalate (PET). The successful formation of the flexible Cu/PET composite films is confirmed by X-ray diffraction (XRD). The surface morphology of Cu/PET is studied by atomic force microscopy (AFM). The results show that the surface roughness increased from 22.6 nm for PET to 45.3 nm after 40 min of deposited Cu/PET. The sheet resistance decreases from $5.16\times 10^4\mathrm{\Omega }$ to $1.3\times 10^4\mathrm{\Omega }$ and resistivity decreases from $2.3\times 10^{-2}\mathrm{\Omega }\cdot \mathrm{\text{cm}}$ to $1.77\times 10^{-2}\mathrm{\Omega }\cdot \mathrm{\text{cm}}$, as the Cu deposition time increases from 20 min to 60 min. Moreover, Young’s modulus increases from 2.82 GPa to 2.96 GPa and the adhesion force enhances from 14.7 nN to 29.90 nN after 40 min of Cu deposition. The DC electrical conductivity at 300 V is improved from $1.75\times 10^{-8}$ S.cm${}^{-1}$ to $3.57\times 10^{-8}$ S.cm${}^{-1}$ after 60 min of Cu deposition. The results show the deposited Cu on flexible PET platform clearly exhibits improvement over pristine PET in the mechanical and electrical properties which render it useful for a broad range of dielectric applications.

Zinc-phosphate glasses with the addition of B₂O₃ were prepared by using the melt quench technique. These glasses had a mol% composition of 30ZnO-xB₂O₃-(70-x)P₂O₅. The quantity x had values of 10–40 mol%. The mass density of these glasses was found to be in the range of 2.4912–3.0142 g/cm³. The oxygen packing density and molar volume were estimated to lie in the range 192.385–286.026 g-atom/liter and 46.78–31.46 cm³ respectively. The absorption spectra of these glasses were recorded in the range of 190 to 1100 nm. No sharp edges were found in the optical spectra, which confirms the amorphous nature of these glasses. The optical band gap energies were determined to be in the range of 2.40–3.00 eV. A decreasing behavior in optical band gap energy was seen due to the increasing concentration of B₂O₃. The extent of band tailing was worked out from the Urbach plots, which showed an exponential dependence of absorption coefficients on photon energies.

The structural, elastic and electronic properties of Ti₄N₃ and Ti₆N₅ have been systematically studied by first-principles calculations based on density functional theory (DFT) with generalized gradient approximation (GGA) and local density approximation (LDA). Basic physical properties for Ti₄N₃ and Ti₆N₅, such as the lattice constants, the bulk modulus, shear modulus, and elastic constants are calculated. The results show that Ti₄N₃ and Ti₆N₅ are mechanically stable under ambient pressure. The phonon dispersion spectra are researched throughout the Brillouin zone via the linear response approach as implemented in the CASTEP code, which indicate the optimized structures are stable dynamically. The Young’s modulus E and Poisson’s ratios $\nu$ are also determined within the framework of the Voigt–Reuss–Hill approximation. The analyses show that Ti₄N₃ is more ductile than Ti₆N₅ at the same pressure and ductility increases as the pressure increases. Moreover, the anisotropies of the Ti₄N₃ and Ti₆N₅ are discussed by the Young’s modulus at different directions, and the results indicate that the anisotropy of the two Ti–N compounds is obvious. The total density of states (TDOS) and partial density of states (PDOS) show that the TDOS of TiN, Ti₄N₃ and Ti₆N₅ originate mainly from Ti “d” and N “p” states. The results show that Ti₄N₃ and Ti₆N₅ present semimetal character. Pressure makes the level range of DOS significantly extended, for TiN, Ti₄N₃ and Ti₆N₅. The TDOS decreases with the pressure rise, at Fermi level.

In this work, pure indium and aluminum targets were co-sputtered in a reactive argon–nitrogen environment at 200°C to deposit InAlN film on the GaAs substrate in the presence of a ZnO buffer layer. The as-grown film was annealed at 750°C for 1 h in a high temperature furnace under nitrogen ambient. XRD pattern of the as-grown film did not display any diffraction peak relating to the InAlN due to its poor structural crystallinity, however, the annealed film exhibited InAlN diffraction peaks corresponding to (002), (101) and (102) planes. A significant increase in the grain size and the surface roughness was observed after the films' annealing. Raman spectroscopy revealed A₁ (LO) and E₂ (high) phonon modes whereas the PL analysis showed a luminescence peak at 2 eV in the annealed film. The Hall measurements indicated an increase in the carrier concentration and electron mobility after the annealing which was accompanied by a decrease in electrical resistivity of the film. The dark current–voltage (I–V) characteristics of the as-grown and the annealed films were also recorded to investigate the barrier height and the ideality factor.

Gold (Au) thin films with thickness of 35nm were prepared by electron beam deposition onto flat glass substrates under high vacuum $(5.3\times 10^{-3}$Pa) condition and they were annealed in the range of 573–873 K for 1 and 2h in atmospheric pressure. The influence of the annealing temperature on the evolution of Au thin film to nano–micro particles was studied. Moreover, the basic properties of the films, namely morphological, structural and optical were investigated. The X-ray diffraction (XRD) analysis revealed that the Au thin films were cubic structure phase with lattice parameter around $a=4.0786$Å. The most preferential orientation is along (111) planes for all Au films. The lattice parameter and grain size in the films were calculated by X-ray patterns and correlated with annealing temperatures. The obtained results of ultraviolet–visible spectrometry (UV–Vis) indicate that with increasing annealing temperature, the surface plasmon resonance peak of gold nanocrystallite will disappear which implies the size of particles are grown. Field-emission scanning electron microscopy (FE-SEM) results show that the prepared gold thin films have been converted to nano–micro gold particles in different annealing temperatures. These results lead to controlling the size of produced nanocrystallite.

$\beta$-In₂S₃ thin films ($\mathrm{\text{S/In}}=1$, 2 and 4) were prepared using the pneumatic spray pyrolysis (PSP) route to analyze the effect of the S/In ratio on the physical properties. These properties were conducted using the photothermal deflection spectroscopy (PDS) method. The PDS signal amplitudes as a function of wavelength show multiple reflections which appear for all prepared In₂S₃ films. Such multiple reflections indicate homogeneity and high crystalline quality of the films. The deduced values of the optical band gap vary in the range 2.55–2.65eV. The highest thermal diffusivity is obtained for $\mathrm{\text{S/In}}=2$. The product ($\mu \cdot \tau$) is found in order of 10${}^{-8}$cm${}^{-1}$/V. The estimated carrier diffusion lengths are 0.06, 0.11 and 0.09$\mu$m for films corresponding to $\mathrm{\text{S/In}}=1$, 2 and 4, respectively. Defect absorption in $\beta$-In₂S₃ films is also investigated by PDS. Five absorption peaks are observed. These absorption peaks contain defect information in the band gap. Hence, this work evidences that $\beta$-In₂S₃ is a multi-functional material that can be used in optoelectronic, photovoltaic and visible-irradiation photocatalyst applications.

Purpose: This study investigated the effects of grinding, polishing and aging on physical properties using self-made zirconia and commonly used ultraclear ceramic materials and glass ceramics in the clinic. Methods: The samples were prepared using 3% yttria-stabilized zirconia ceramic (3Y-TZP) powder containing alumina, which was granulated by ball milling. Then, it is pressed into a circular sheet together with Upcera and Wieland materials. The glass ceramic materials are molded. Finally, all materials were subjected to hydrothermal aging. Results: The self-made zirconia had better permeability than the commonly used ultratransparent ceramic materials and glass ceramics. The polishing after grinding improved the surface morphology and roughness of tooth transparent ceramic materials; Polishing after grinding improved the aging resistance of zirconia materials. The bending strength of self-made samples was less than that of two kinds of ceramics commonly used in clinic, but greater than that of glass ceramics. Aging improved the bending strength of zirconia. Conclusions: The self-made zirconia had better permeability than ultratransparent all-ceramic materials and glass ceramics, and its bending strength was better than that of glass ceramics. Grinding and polishing could improve not only the surface morphology and roughness but also the strength and aging resistance.

We report on the structure and morphology of thermoexfoliated graphite (TEG) powders and TEG–metal (Co, Cu, Ni) powders. Electrodynamic parameters of the compacted TEG and TEG–metal specimens have been studied along the compacting axis (c axis) within the range of electromagnetic radiation frequencies between 25.5 and 37.5 GHz. Metal particles attached to the surface of the TEG particles yield enhanced radiation shielding within the entire frequency range. Moreover, it is observed that the absorption coefficient increases with the increase in conductivity of the metal particles and is enhanced due to a high concentration of TEG–metal boundaries, which promote multiple reflections.

Zinc oxide (ZnO) films have been sputter coated over glass substrates at different cathode powers. Influence of cathode power on physical characteristics of ZnO samples was analyzed using X-ray diffractometer (XRD), field emission-scanning electron microscopy (FE-SEM), UV-Visible spectrophotometer and four-point probe (FPP) method. XRD patterns exhibited $c$-axis-oriented ZnO and enhanced crystallinity with increase in cathode power due to the increase in adatom mobility. Uniformly arranged spherical grains were observed from FE-SEM images. The grain size increased from 25 to 40nm with increase in power. All samples exhibited high electrical resistance (G$\mathrm{\Omega }$) which is compatible for piezoelectric application.

Zinc oxide nanoparticles (ZnO-NPs) are widely utilized in many applications due to distinct physical and chemical characteristics. There are growing concerns that abundant use of ZnO-NPs can cause harm to humans and the environment. There is a substantial problem with reproducibility in nanotoxicology research due to the inherent properties of nanoparticles. Dispersion media are used for the preparation of nanoparticles. However, the physical and biological behaviors of ZnO-NPs in aqueous dispersion media are poorly understood. In this study, we investigated the effect of ZnO-NPs on the viability of SH-SY5Y cells. Our results showed that ZnO-NPs diluted from water-dispersed stock solution caused significant cell death at a much lower dose compared to their counterpart diluted from the phosphate-buffered saline (PBS)-dispersed stock solution. Electron microscopic data indicated that ZnO-NPs from the PBS-dispersed stock solution form much larger agglomerates compared to the one from the water-dispersed stock solution. From these data, we can conclude that the types of media used for particle dispersion impact the change in the physical property and cytotoxicity of ZnO-NPs.

In the present review, we show how the chemistry of lanthanide macrocyclic complexes, which began almost 50 years ago in Russia, is still very active. Additionally to bisphthalocyanines complexes, triple-decker, but also quadruple- and quintuple-decker complexes have been synthesized via new chemical routes. The driving force for the development of this chemistry arises from the wide range of possible applications. Owing to their very high conductivity, compared to that of monophthalocyanines, LnPc₂ and Ln₂Pc₃ complexes are used as molecular semiconductors in electronic devices. The radical nature of LnPc₂ complexes makes them easily oxidized and reduced. This is the reason why they are particularly promising materials for the development of new chemical sensors, associated with both conductimetric and optical transducers.

As new generation mediums for high-performance cooling and thermal management, appropriate candidates for the liquid metal should have a low enough melting point, small viscosity, high thermal conductivity, and large heat capacity. Meanwhile, it must not be poisonous and caustic. The most important prerequisite is that the working liquid metal needs to remain in liquid state when its cooling role is being performed under an appropriate temperature range for computer chips, which is generally below 100°C. It is commonly held that a metal appears as a rigid block. With this impression in mind, the fact is often ignored that those alloys with extremely low melting points, several degrees centigrade above zero, actually stay in the liquid state around room temperature. Among the various liquid metals, it can be found that liquid gallium or its alloys can serve as a perfect candidate for the heat transfer medium in a wide variety of devices and systems. Unfortunately, there have been limited efforts to apply such liquid metals to cool high-power electronic components, especially computer chips, until around 2002 [1].

An in-depth analysis of the thermal properties of liquid metals, such as gallium, strongly suggests that they are well suited for the cooling of computer chips owing to their low melting point. In fact, gallium can generally be kept in a liquid state at a temperature much lower than the room temperature due to its large sub-cooling point. It turns out to be an important merit for gallium-based alloys to be used as the cooling fluid. The low melting point and very low vapor pressure of such a liquid metal make it easy to handle, and its high thermal conductivity guarantees excellent cooling performance. Further, the low kinetic viscosity of liquid metal improves its capability for heat removal, especially at the liquid–solid interface and enhances its attractiveness as a new-generation coolant. The normal (dynamic) viscosity of gallium is about 1.5 times that of water, which means that it can be pumped through small channels with relative ease. The surface tension of liquid metals is much higher than that of water, which makes them immune to the presence of small cracks or channels in case of an imperfect seal, which would be a serious leakage for water as a cooling fluid. Besides, liquid metals are non-toxic and relatively cheap. The two principal advantages lie in their superior thermophysical properties of absorbing heat away from a hot chip and the ability to pump these electrically conductive liquids efficiently with silent, vibration-free, non-moving, magnetofluid-dynamic (MFD) pumps. All these compelling properties warrant their future applications in chip cooling technology.

This chapter is dedicated to illustrate the typical liquid metal medium and related properties regarding advanced cooling. Unlike most of the conventional cooling fluids [2], a liquid metal offers tremendous opportunities for the coming society.

Experimental results show that the water retention value and carboxyl content improved with the increase of beating degree. Beating can effectively improve the OCC pulp strength properties from 23° SR to 67° SR. The performance of the paper generally increased with the increase in beating degrees. When beating combined with laccase/ histidine, the physical properties of the pulp had undergone great changes. The laccase/ histidine/treated pulp gave the highest WRV value and carboxyl content, which led to the highest bonding of pulp fibers resulting in the highest strength of the paper.

This paper aims to establish a relationship between the physical properties of powder mixture and its hygroscopicity. The powder mixtures of hawthorn leaf were obtained by different kinds of drying technology and mixed with microcrystalline cellulose (MCC) and starch, respectively, at a series of ratio. The hygroscopicity for powder mixture was evaluated by monitoring such responses as equilibrium moisture (f) and absorption rate constant (k). The effect of physical properties on hygroscopicity was analyzed by stepwise regression. Specific surface area (SSA), pore volume (PV), particle size (D90), angle of repose (AOR), bulk density (ρb), tapped density (ρt), Hausner ratio (HR) and critical relative humidity (CRH) were proved as the key parameter involving in hygroscopicity of powder mixture. It was suggested from the data that (1) equilibrium moisture was positively correlated to PV, D90 and negatively correlated with SSA, HR, CRH. There was a negative correlation between absorption rate constant with ρt and AOR, and a positive correlation with ρb, HR and CRH; (2) different concentrations of ethanol for extraction of hawthorn leaf would lead to different extract composition, therefore, the effect of physical property parameters on the hygroscopicity of powder mixture of hawthorn leaf would be variable.

This paper studies the mixture of cement mortar with a phase change material (PCM) and analyzes the changes in mechanical and physical performances. The experimental results demonstrate that an increase in PCM content results in decreases in consistency, compressive strength, bulk density and water retention. Therefore, these results can provide a reference for the application of phase change materials in practical engineering conditions.

Dipterocarpaceae is the economically most important family in the forests of Indomalesia, producing more timber than the trees of all other families combined. With very few exceptions, Dipterocarpaceae are medium-sized or large to very large trees, and their economic value depends on the many useful kinds of timber they produce. The occurrence of vertical intercellular (resin) canals in combination with tyloses is the best diagnostic character set of South-East Asian Dipterocarpaceae. Structural differentiation within the family is sufficient for delimiting groups or genera. Biological, physical, and strength as well as working properties extend over a wide range to qualify the great majority of dipterocarp timbers for general utility purposes, yet only very few can be properly classified as 'special-purpose' woods. Lacking the specific attractiveness of typical fancy woods, dipterocarp timbers owe their very success in the market mainly to such factors as availability of large dimensions and volumes, continuity of supply, wide range of technical applications, skillfull marketing concepts, and a very favourable relation between cost and performance in service.

The rheological properties and the components analyzing of styrene butadiene styrene (SBS) inhibitor modified asphalt was investigated by dynamic shear rheology (DSR) and four composition analyzer, respectively. Compared with the compositions and fundamental properties of asphalts, the results show that the addition of SBS inhibitor to asphalt results in reducing of the penetration and ductility and enhancement of the softening point. The complex shear modulus reduces slightly while the phase angle increases when the inhibitors are added. Meanwhile, the components of saturates and aromatics change slightly. With the increase of SBS inhibitor, the content of resin decreased and the content of asphaltene increased.