THEORY OF LC BIOMEMBRANE——A PROBE INTO SOFT CONDENSED MATTER PHYSICS

Soft condensed-state physics is a disciplinary frontier of 20th-century physics. An interdiscipline in nature, it involves biology, chemistry and even pure mathematics. Taking the liquid crystal (LC) biomembrane as an example, this article expounds the current development trend of this new and promising branch of contemporary physics.

Theoretical Study of the Phenomenon of Cold Fusion within Condensed Matter and Analysis of Phases （α,β,γ）

The aim of this work is to explain the deuteron-deuteron reactions within palladium lattice by means of the coherence theory of nuclear and condensed matter. The coherence model of condensed matter affirms that within a deuteron-loaded palladium lattice there are three different plasmas： electrons, ions and deuterons plasma. Then, according to the loading percentage x = D/Pd, the deuterium ions can take place on the octahedral sites or in the tetrahedral on the （1, 0, 0）-plane. Further, the present work is concentrated on Palladium because, when subjected to thermodynamic stress, this metal has been seen to give results which are interesting from both the theoretical and experimental points of view. Moreover in Pd lattice we can correlate the deuterium loading with D-Pd system phases （i.e. α,β and γ） by means of theory of condensed matter.

Photoacoustic measurement of the thermal property of condensed matter using a strong light-absorbing surface layer

By using a strong light-absorbing surface layer and front-surface illumination with a low power He-Ne laser ( 6mW), photoacoustic measurements of the thermal effusivities of materials have been made, based on the photoacoustic theory, derived in this paper, of condensed matter with a strong light- absorbing surface layer. This method can eliminate the stray light, give full play to the power of the light irradiation, and improve the signal to noise ratio. The experiment results are in good agreement with the theoretical values.

Why the Central Monster in M87 Should Be a Massive DEO Rather than a SMBH?

In this paper, we show that massive envelopes made of highly compressed normal matter surrounding dark objects (DEOs) can curve the surrounding spacetime and make the systems observationally indistinguishable from their massive black hole counterparts. DEOs are new astrophysical objects that are made up of entropy-free incompressible supranuclear dense superfluid (SuSu-matter), embedded in flat spacetimes and invisible to outside observers, practically trapped in false vacua. Based on highly accurate numerical modelling of the internal structures of pulsars and massive neutron stars, and in combination with using a large variety of EOSs, we show that the mass range of DEOs is practically unbounded from above: it spans those of massive neutron stars, stellar and even supermassive black holes: thanks to the universal maximum density of normal matter, , beyond which normal matter converts into SuSu-matter. We apply the scenario to the Crab and Vela pulsars, the massive magnetar PSR J0740 6620, the presumably massive NS formed in GW170817, and the SMBHs in Sgr A* and M87*. Our numerical results also reveal that DEO-Envelope systems not only mimic massive BHs nicely but also indicate that massive DEOs can hide vast amounts of matter capable of turning our universe into a SuSu-matter-dominated one, essentially trapped in false vacua.

The Origin of the Flat Rotation Curves in Spiral Galaxies: The Hidden Roles of Glitching SMDEOs and Emission of Gravitational Waves

Supermassive DEOs (SMDEOs) are cosmologically evolved objects made of irreducible incompressible supranuclear dense superfluids: The state we consider to govern the matter inside the cores of massive neutron stars. These cores are practically trapped in false vacua, rendering their detection by outside observers impossible. Based on massive parallel computations and theoretical investigations, we show that SMDEOs at the centres of spiral galaxies that are surrounded by massive rotating torii of normal matter may serve as powerful sources for gravitational waves carrying away roughly 1042 erg/s. Due to the extensive cooling by GWs, the SMDEO-Torus systems undergo glitching, through which both rotational and gravitational energies are abruptly ejected into the ambient media, during which the topologies of the embedding spacetimes change from curved into flatter ones, thereby triggering a burst gravitational energy of order 1059 erg. Also, the effects of glitches found to alter the force balance of objects in the Lagrangian-L1 region between the central SMDEO-Torus system and the bulge, enforcing the enclosed objects to develop violent motions, that may explain the origin of the rotational curve irregularities observed in the innermost part of spiral galaxies. Our study shows that the generated GWs at the centres of galaxies, which traverse billions of objects during their outward propagations throughout the entire galaxy, lose energy due to repeatedly squeezing and stretching the objects. Here, we find that these interactions may serve as damping processes that give rise to the formation of collective forces f∝m(r)/r, that point outward, endowing the objects with the observed flat rotation curves. Our approach predicts a correlation between the baryonic mass and the rotation velocities in galaxies, which is in line with the Tully-Fisher relation. The here-presented self-consistent approach explains nicely the observed rotation curves without invoking dark matter or modifying Newtonian gravitation in the low-field approximation.

First-Principles Study of Structural Stabilities, Electronic and Optical Properties of SrF2 under High Pressure

An investigation of structural stabilities, electronic and optical properties of SrF2 under high pressure is conducted using a first-principles calculation based on density functional theory （DFT） with the plane wave basis set as implemented in the CASTEP code. Our results predict that the second high-pressure phase of SrF2 is of a Ni2In- type structure, and demonstrate that the sequence of the pressure-induced phase transition of SrF2 is the fluorite structure （Fm3m） to the PbC12-type structure （Pnma）, and to the Ni2In-type phase （P63/mmc）. The first and second phase transition pressures are 5. 77 and 45.58 GPa, respectively. The energy gap increases initially with pressure in the Fm3m, and begins to decrease in the Pnma phases at 30 GPa. The band gap overlap metallization does not occur up to 210 GPa. The pressure effect on the optical properties is discussed.

Existence of Shear Horizontal Surface Waves in a Magneto-Electro-Elastic Material

The existence of shear horizontal surface waves in a magneto-electro-elastic （MEE） half-space with hexagonal （6mm） symmetry is investigated. The surface of the MEE half-space is mechanically free, but subjected to four types of electromagnetic boundary conditions. These boundary conditions are electrically open/magnetically closed, electrically open/magnetically open, electrically closed/magnetically open and electrically closed/magnetically dosed. It is shown that except for the electrically open/magnetically closed condition, the three other sets of electromagnetic boundary conditions allow the propagation of shear horizontal surface waves.

AlGaN-Based Deep-Ultraviolet Light Emitting Diodes Fabricated on AlN/sapphire Template

We report on the growth and fabrication of deep ultraviolet （DUV） light emitting diodes （LEDs） on an AIN template which was grown on a pulsed atomic-layer epitaxial buffer layer. Threading dislocation densities in the AlN layer are greatly decreased with the introduction of this buffer layer. The crystalline quality of the AlGaN epilayer is further improved by using a low-temperature GaN interlayer between AlGaN and AlN. Electroluminescences of different DUV-LED devices at a wavelength of between 262 and 317nm are demonstrated. To improve the hole concentration of p-type AlGaN, Mg-doping with trimethylindium assistance approach is performed. It is found that the serial resistance of DUV-LED decreases and the performance of DUV-LED such as EL properties is improved.

Synthesis and Properties of Magnetic Composites of Carbon Nanotubes/Fe Nanoparticle

Magnetic composites of carbon nanotubes （CNTs） are synthesized by the in situ catalytic decomposition of benzene at temperatures as low as 400℃ over Fe nanoparticles （mean grain size = 26 nm） produced by sol-gel fabrication and hydrogen reduction. The yield of CNT composite is up to about 3025% in a run of 6 h. FE- SEM and HRTEM investigations reveal that one-dimensional carbon species are produced in a large quantity. A relatively high value of magnetization is observed for the composite due to the encapsulation of ferromagnetic Fe3 C and/or α-Fe. The method is suitable for the mass-production of CNT composites that contain magnetic nanoparticles.

Phase-Transition and Magnetic Moment of the Gd3＋ Ion in the Gd2Fe17 Compound

The structure and magnetic phase transitions of the Gd2Fe17 compound are investigated by using a differential thermal/thermogravimetric analyzer, x-ray diffraction, and magnetization measurements. The result shows that there are two phase structures for the Gd2Fe17 compound： the hexagonal Th2Nilr-type structure at high temperatures （above 1243℃）, and the rhombohedral Th2Zn17-type structure, respectively. A method to measure the magnetic moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound is presented. The moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound from 77 to 500 K are measured in this way with a vibrating sample magnetometer. A detailed discussion is presented.

Energy Transfer from Ce^3＋ to Eu^2＋ in LiSrBO3 and Its Potential Application in UV-LED-Based White LEDs

Ce3＋/Eu2＋ codoped LiSrBO3 phosphor is synthesized, and its luminescent characteristics are investigated. LiSrBO3：Ce3＋,Eu2＋ phosphor exhibits varied hues from blue to white and eventually to yellow by resonance-type energy transfer from Ce3＋ ion to Eu2＋ ion and tuning the relative proportion of Ce3＋/Eu2＋ properly. Energy transfer mechanism in LiSrBOa：Ce3＋, Eu2＋ phosphor is dominated by the dipole-dipole interaction, and the critical distance of the energy transfer is estimated to be about 2 nm by both spectral overlap and concentration quenching methods. Under UV radiation, white light is generated by coupling 436 and 565nm emission bands attributed to Ce3＋ and Eu2＋ radiations, respectively.

Simulation of Light Intensification Induced by Defects of Polished Fused Silica

Light intensity distribution in the vicinity of inclusions and etched cracks in polished fused silica at wavelength scale are simulated by using the finite-difference time-domain algorithm. Light intensity enhancement factor as functions of diameter and refractive index of inclusions are investigated, more than 10 times that of incident beam is obtained in the simulation. We model the etched crack in close proximity to a real structure, which is characterized by AFM. We find that the peak light intensity of the crack is a function of its cross sectional breadth depth ratio, providing good hints for the effective processing of fused silica samples to improve the damage threshold.

Mechanical Reinforcement and Piezoelectric Properties of PZT Ceramics Embedded with Nano-Crystalline

The double-scale lead zirconate titanate （PZT） piezoelectric ceramics were prepared by the solid state processing with PZT nano-crystalline and micro-powder. The microstructures, electrical and mechanical properties of the double-scale PZT are investigated. All the sintered ceramics exhibit a single perovskite structure and the grain size of the dou ble-scale PZT reduces due to the incorporation of PZT nano-crystalline. Compared to normal PZT, the mechanical properties increase significantly and the piezoelectric properties decrease slightly. Mechanisms responsible for the reinforcement of the double-scale PZT are discussed.

Preparation and Thermal Characterization of Diamond-Like Carbon Films

Diamond-like carbon （DLC） films are prepared on silicon substrates by microwave electron cyclotron resonance plasma enhanced chemical vapor deposition. Raman spectroscopy indicates that the films have an amorphous structure and typical characteristics. The topographies of the films are presented by AFM images. Effective thermal conductivities of the films are measured using a nanosecond pulsed photothermal reflectance method. The results show that thermal conductivity is dominated by the microstructure of the films.

Effects of Grain Boundary Barrier in ZnO/Si Heterostructure

The influence of ZnO microstructure on electrical barriers is investigated using capacitance-voltage （C - V）, current-voltage （I- V） and deep level transient spectroscopy （DLTS） measurements. A deep level center located at Ec - 0.24 eV obtained by DLTS in the ZnO films is an intrinsic defect related to Zni. The surface states in the ZnO grains that have acceptor behavior of capturing electrons from Zni defects result in the formation of grain barriers. In addition, we find that the current transport is dominated by grain barriers after annealing at 600℃ at 02 ambient. With the increment of the annealing temperature, the current transport mechanism of ZnO/Si heterostructure is mainly dominated by thermo-emission.

Effects of Annealing Temperature on Structural and Optical Properties of ZnO Thin Films

The effects of annealing temperature on the structural and optical properties of ZnO films grown on Si （100） substrates by sol-gel spin-coating are investigated. The structural and optical properties are characterized by x-ray diffraction, scanning electron microscopy and photoluminescence spectra. X-ray diffraction analysis shows the crystal quality of ZnO films becomes better after annealing at high temperature. The grain size increases with the temperature increasing. It is found that the tensile stress in the plane of ZnO films first increases and then decreases with the annealing temperature increasing, reaching the maximum value of 1.8 GPa at 700℃. PL spectra of ZnO films annealed at various temperatures consists of a near band edge emission around 380 nm and visible emissions due to the electronic defects, which are related to deep level emissions, such as oxide antisite （OZn）, interstitial oxygen （Oi）, interstitial zinc （Zni） and zinc vacancy （VZn^-）, which are generated during annealing process. The evolution of defects is analyzed by PL spectra based on the energy of the electronic transitions.

A Fractal Model for Effective Thermal Conductivity of Isotropic Porous Silica Low-k Materials

We establish a new model based on fractal theory and cubic spline interpolation to study the effective thermal conductivity of isotropic porous silica low-k materials. A 3D fractal model is introduced to describe the structure of the silica xerogel and silica hybrid materials （such as methylsilsesquioxane, MSQ）. Combined with fractal structure, a more suitable medium approximation is developed to study the isotropic porous silica xerogel and MSQ materials. Cubic spline interpolation for fitting discrete predictions from the fractal model is used to obtain the continuous function of the effective thermal conductivity versus porosity. Compared with other common models, the effective thermal conductivity predicted by our model presents better agreement with the experimental data for all porosity. These results indicate that the proposed model is valid.