The molecular scales behavior of interfacial water at the solid/liquid interfaces is of a fundamental significance in a diverse set of technical and scientific contexts, ranging from the efficiency of oil mining to the activity of biological molecules. Recently, it has become recognized that, both the physical interactions and the surface morphology have significant impact on the behavior of interfacial water, including the water structures as well as the wetting properties of the surface. In this review, we summarize some of recent advances in the atom-level pictures of the interfacial water, which exhibits the ordered character on various solid surfaces at room or cryogenic temperature. Special focus has been devoted to the wetting phenomenon of "ordered water monolayer that does not completely wet water" and the underlying mechanism on model and some real solid surfaces at room temperature. The possible applications of this phenomenon are also discussed.

Water shows anomalies di erent from most of other materials. Di erent sceniaros have been proposed to explain water anomalies, among which the liquid-liquid phase transition (LLPT) is the most discussed one. It attributes water anomalies to the existence of a hypothesized liquid-liquid critical point (LLCP) buried deep in the supercooled region. We briefly review the recent experimental and theoretical progresses on the study of the LLPT in water. These studies include the discussion on the existence of the first order LLPT in supercooled water and the detection of liquid-liquid critical point. Simulational results of di erent water models for LLPT and the experimental evidence in confined water are also discussed.

The influence of water permeates almost all areas including biochemistry, chemistry, physics and is particularly evident in phenomena occurring at the interfaces of solid surface such as SiC nanocrystals, which are promising nanomaterials and exhibit unique surface chemical properties. In this paper, the quantum confinement effect and stability of 3C-SiC nanocrystals in aqueous solution as well as photoluminescence properties in water suspensions with different pH values are reviewed based on design and analysis of surface structures. On this basis, the significant progress of 3C-SiC nanocrystals in efficiently splitting water into usable hydrogen is summarized and the relative mechanisms are described. In addition, the water-soluble 3C-SiC quantum dots as robust and nontoxic biological probes and labels also are introduced as well as future prospects given.

The confinements of water can be divided into two main categories, namely, the confinements on surface or interface and the confinements in bulk water. By adding ions or applying electric field, the intensity and distribution of the hydrogen bonds can be greatly affected. These are collectively known as confinement on water surface or interface, which has potential applications in life science and industries involving evaporation control. Confined bulk water could be found everywhere in nature, such as in granular and porous materials, macromolecules and gels, etc. The investigation of the physical properties and the transports of the confined bulk water will contribute to understanding certain types of life activities such as the water transport in plant and in new application of extracting the shale oil and water.

Water confined in nanoscale space behaves quite differently from that in the bulk. For example, in biological aquaporins and in carbon nanotubes, the traversing water molecules form a single file configuration. Water would stay in vapor state in extremely hydrophobic narrow nanopores owing to the physicochemical interactions between the water molecules and the surface of the nanopore. A spontaneous wet-dry transition has been identified in both biological and artificial nanopores. The nanopore is either fulfilled with liquid water or completely empty. Based on this mechanism, the wetting and dewetting processes inside nanopores have been further developed into highly efficient nanofluidic gates that can be switched by external stimuli, such as light irradiation, electric potential, temperature, and mechanical pressure. This review briefly covers the recent progress in the special wettability in nanoconfined environment, water transportation through biological or artificial nanochannels, as well as the smart nanofluidic gating system controlled by the water wettability.

The proton spectral and angular distributions simultaneously within the target normal direction and laser propagation direction by using an angle-resolved proton energy spectrometer are studied. For the protons generated in the interactions of 100 fs, 800 nm laser pulses with aluminum foil targets, the deviations of proton beam centers of different energies from the target normal direction towards the laser propagation direction are different. This is probably because of the toroidal magnetic fields generated at the rear target surface, which deflect protons transversely. As a result, protons in low energy range have large deviation angles, protons in middle energy range have the smallest deviation angles, while protons in high energy tail have large deviation angles.

Hydrogels are a class of special materials that contain a large amount of water and behave like rubber. These materials have found broad applications in tissue engineering, cell culturing, regenerative medicine etc. Recently, the exploration of peptide-based supramolecular hydrogels has greatly expanded the repertoire of hydrogels suitable for biomedical applications. However, the mechanical properties of peptide-based hydrogels are intrinsically weak. Therefore, it is crucial to develop methods that can improve the mechanical stability of such peptide-based hydrogels. In this review, we explore the factors that determine or influence the mechanical stability of peptide-based hydrogels and summarize several key elements that may guide scientists to achieve mechanically improved hydrogels. In addition, we exemplified several methods that have been successfully developed to prepare hydrogels with enhanced mechanical stability. These mechanically strong peptide-based hydrogels may find broad applications as novel biomaterials. It is still challenging to engineer hydrogels in order to mimic the mechanical properties of biological tissues. More hydrogel materials with optimal mechanical properties suitable for various types of biological applications will be available in the near future.

We investigate here various kinds of semi-product subgroups of Poincaré group in the scheme of Cohen-Glashow's very special relativity along the deformation approach by Gibbons- Gomis-Pope. For each proper Poincaré subgroup which is a semi-product of proper lorentz group with the spacetime translation group T(4), we investigate all possible deformations and obtain all the possible natural representations inherited from the 5-d representation of Poincaré group. We find from the obtained natural representation that rotation operation may have additional accompanied scale transformation when the original Lorentz subgroup is deformed and the boost operation gets the additional accompanied scale transformation in all the deformation cases. The additional accompanied scale transformation has a strong constrain on the possible invariant metric function of the corresponding geometry and the field theories in the spacetime with the corresponding geometry.

A two-mode entangled state was generated experimentally through mixing two squeezed lights from two optical parametric amplifiers on a 50/50 beam splitter. The entangled beams were measured by means of two pairs of balanced homodyne detection systems respectively. The relative phases between the local beams and the detected beams can be locked by using the optical phase modulation technique. The covariance matrix of the two-mode entangled state was obtained when the relative phase of the local beam and the detected beam in one homodyne detection system is locked and the other is scanned. This method provides a way by which one can extract the covariance matrix of any selected quadrature components of two-mode Gaussian state.

A quadratic coupling enabled parametric oscillation in an optomechanical system is used to modify the nonlinear static responses of a mechanical oscillator with a normal linear coupling. The mean value study showed that the modification of the static response on a mechanical oscillator is extremely sensitive and useful, which can readily enhance or suppress the nonlinear displacement response from a bistability case to singlet or triplet well case, freely bifurcating the equilibrium position from one to two or three. The static equilibria structure and the stability regions for mean-value controls on nano-oscillator were analyzed under the possible modification parameters.

Significantly improved electrostatic discharge (ESD) properties of InGaN/GaN-based UV light-emitting diode (LED) with inserting p-GaN/p-AlGaN superlattice (p-SLs) layers (instead of p-AlGaN single layer) between multiple quantum wells and Mg-doped GaN layer are reported. The pass yield of the LEDs increased from 73.53% to 93.81% under negative 2000 V ESD pulses. In addition, the light output power (LOP) and efficiency droop at high injection current were also improved. The mechanism of the enhanced ESD properties was then investigated. After excluding the effect of capacitance modulation, high-resolution X-ray diffraction (XRD) and atomic force microscope (AFM) measurements demonstrated that the dominant mechanism of the enhanced ESD properties is the material quality improved by p-SLs, which indicated less leakage paths, rather than the current spreading improved by p-SLs.

Anatase titanium dioxide nanowire arrays were prepared by hydrothermally oxidizing titanium foils in aqueous alkali and transferred onto fluorinated tin oxide (FTO) glass for use as the photoanodes of front side illuminated dye-sensitized solar cells (DSCs). Electrochemical impedance spectroscopy (EIS) measurement was applied to compare the electron transport and recombination properties of DSCs using TiO₂ nanowire films and TiO₂ nanoparticle films as photoanodes. It was found that the nanowire array films possess smaller electron transport resistance (R_t) and larger electron diffusion length (L_e) in the photoanodes, suggesting that the nanowire arrays can enhance the electron transport rate and have a potential to improve the charge collection efficiency of DSCs.

In this paper, we derive Darboux transformation of the inhomogeneous Hirota and the Maxwell-Bloch (IH-MB) equations which are governed by femtosecond pulse propagation through inhomogeneous doped fibre. The determinant representation of Darboux transformation is used to derive soliton solutions, positon solutions to the IH-MB equations.

This paper studies the damage-viscoelastic behavior of composite solid propellants of solid rocket motors (SRM). Based on viscoelastic theories and strain equivalent hypothesis in damage mechanics, a three-dimensional (3-D) nonlinear viscoelastic constitutive model incorporating with damage is developed. The resulting viscoelastic constitutive equations are numerically discretized by integration algorithm, and a stress-updating method is presented by solving nonlinear equations according to the Newton-Raphson method. A material subroutine of stress-updating is made up and embedded into commercial code of Abaqus. The material subroutine is validated through typical examples. Our results indicate that the finite element results are in good agreement with the analytical ones and have high accuracy, and the suggested method and designed subroutine are efficient and can be further applied to damage-coupling structural analysis of practical SRM grain.

Based on Tanaka and Mura's fatigue model and Griffith theory for fracture, an energy-equilibrium model was proposed to explain the complex stress effect on fatigue behavior. When the summation of the elastic strain energy release and the stored strain energy of accumulated dislocations reach the surface energy of a crack, the fatigue crack will initiate in materials. According to this model, for multiaxial stress condition, the orientation of the crack initiation and the initiation life can be deduced from the energy equilibrium equation. For the uniaxial fatigue loading with mean stress, the relation between the maximum stress or the minimum stress and the stress amplitude is in agreement with an ellipse equation on the constant life diagram. If the ratio of the mean stress to stress amplitude is less than a critical value -0.17, and the stress amplitude keeps constant, the fatigue crack initiation life will decrease with the increase of the compress mean stress. In this model, the mean stress does not cause damage accumulation with the fatigue cycles in crack initiation. For this reason, the loading sequence of different load levels would induce the cumulative damage to deviate from the Palmgren-Miner cumulative damage rule. The procedure of estimating the damage under random loading is also discussed.

Free vibration of functionally graded beams with a through-width delamination is investigated. It is assumed that the material property is varied in the thickness direction as power law functions and a single through-width delamination is located parallel to the beam axis. The beam is subdivided into three regions and four elements. Governing equations of the beam segments are derived based on the Timoshenko beam theory and the assumption of ‘constrained mode’. By using the differential quadrature element method to solve the eigenvalue problem of ordinary differential equations governing the free vibration, numerical results for the natural frequencies of the beam are obtained. Natural frequencies of delaminated FGM beam with clamped ends are presented. Effects of parameters of the material gradients, the size and location of delamination on the natural frequency are examined in detail.

An experimental study was conducted to investigate the effects of relative rotation direction on the wake interferences among two tandemwind turbines models. While the oncoming flow conditions were kept in constant during the experiments, turbine power outputs, wind loads acting on the turbines, and wake characteristics behind the turbines were compared quantitatively with turbine models in either co-rotating or counter-rotating configuration. The measurement results reveal that the turbines in counter-rotating would harvest more wind energy from the same oncoming wind, compared with the co-rotating case. While the recovery of the streamwise velocity deficits in the wake flows was found to be almost identical with the turbines operated in either co-rotating or counter-rotating, the significant azimuthal velocity generated in the wake flow behind the upstream turbine is believed to be the reason why the counter-rotating turbines would have a better power production performance. Since the azimuthal flow velocity in the wake flow was found to decrease monotonically with the increasing downstream distance, the benefits of the counter-rotating configuration were found to decrease gradually as the spacing between the tandem turbines increases. While the counter-rotating downstream turbine was found to produce up to 20% more power compared with that of co-rotating configuration with the turbine spacing being about 0.7D, the advantage was found to become almost negligible when the turbine spacing becomes greater than 6.5D. It suggests that the counter-rotating configuration design would be more beneficial to turbines in onshore wind farms due to the smaller turbine spacing (i.e., ~3 rotor diameters for onshore wind farms vs. ~7 rotor diameters for offshore wind farms in the prevailing wind direction), especially for those turbines sited over complex terrains with the turbine spacing only about 1-2 rotor diameters.

Up to now, the most widely used method for transition prediction is the one based on linear stability theory. When it is applied to three-dimensional boundary layers, one has to choose the direction, or path, along which the growth rate of the disturbance is to be integrated. The direction given by using saddle point method in the theory of complex variable function is seen as mathematically most reasonable. However, unlike the saddle point method applied to water waves, here its physical meaning is not so obvious, as the frequency and wave number may be complex. And on some occasions, in advancing the integration of the growth rate of the disturbance, up to a certain location, one may not be able to continue the integration, because the condition for specifying the direction set by the saddle point method can no longer be satisfied on the basis of continuously varying wave number. In this paper, these two problems are discussed, and suggestions for how to do transition prediction under the latter condition are provided.

An experimental study of compressible mixing layers (CMLs) was conducted using planar laser Mie scattering (PLMS) visualizations from condensed ethanol droplets in the flow. Large ensembles of digital images were collected for two flow conditions at convective Mach numbers M_c = 0.11 and 0.47. The coherent vortices, braids and eruptions in the mixing zone were observed, interpreted as evidence of multi-scale, three-dimensional structures at a high Reynolds number. The mixing layers with a large visualized range present two stages along the streamwise direction, corresponding to the initial mixing and the well-developed stage. A new method, the gray level ensemble average method (GLEAM), by virtue of the similarity of the mixing layer, was applied to measure the growth rate of the CML thickness. New evidence for a nonlinear growth of CML is reported, providing an interpretation of previous observations of the scattering of the growth rate.

In this paper, a high-resolution, hybrid compact-WENO scheme is developed based on the minimized dispersion and controllable dissipation reconstruction technique. Firstly, a su cient condition for a family of tri-diagonal compact schemes to have independent dispersion and dissipation is derived. Then, a specific 4th order compact scheme with low dispersion and adjustable dissipation is constructed and analyzed. Finally, the optimized compact scheme is blended with the WENO scheme to form the hybrid scheme. Moreover, the approximation dispersion relation approach is employed to optimize the spectral properties of the nonlinear scheme to yield the true wave propagation behavior of the finite di erence scheme. Several test cases are carried out to verify the highresolution as well as the robust shock-capturing capabilities of the proposed scheme.

The information on the force of extraocular muscles (EOMs) is beneficial for strabismus diagnosis and surgical planning, and a direct and simple method is important for surgeons to obtain these forces. Based on the traditional model, a numerical simulation method was proposed to achieve this aim, and then the active force of the lateral rectus (LR) muscle was successfully simulated when the eye rotated every angle from 0° to 30° in the horizontal plane from the nasal to the temporal side. In order to verify these simulations, the results were compared with the previous experimental data. The comparison shows that the simulation results diverged much more than the experimental data in the range of 0°-10°. The errors were corrected to make the simulation results closer to the experimental data. Finally, a general empirical equation was proposed to evaluate the active force of the LR muscle by fitting these data, which represent the relationship between the simulation forces and the contractive amounts of the LR muscle.

Strong lensing is an e ective way to probing the properties of dark energy. In this paper, we use the strong lensing data to constrain the f(T) theory, which is a new modified gravity to explain the present accelerating cosmic expansion without the need of dark energy. In our discussion, the CMB and BAO data are also added to constrain model parameters tightly and three di erent f(T) models are studied. We find that strong lensing has an important role on constraining f(T) models, and once the CMB+BAO data is added, a tighter constraint is obtained. However, the consistency of our result with what is obtained from SNIa+CMB+BAO is actually model-dependent.

Tharsis is the most prominent volcanic province on Mars, yet the compositions of lava flows and how composition relates to the development of Tharsis are poorly known. Most of Tharsis is covered with air-fall dust, which inhibits spectroscopic determination of lava mineralogy. The Syria-Thaumasia Block (STB) is a complex tectono-volcanic province closely related to the Tharsis bulge. The lava plains of STB have different emplacement ages, which provide an opportunity to examine whether magma composition changed with the evolution of Tharsis. In this study, we assessed the lava plains using Thermal Emission Spectrometer (TES) data. Using derived physical properties, we targeted dust-free regions from four different-aged geological units' surfaces and determined the mineralogical composition by modeling the average TES surface spectrum from each of the four surfaces. All units have similar mineralogy but the younger two units have elevated abundance of high-SiO₂ phases. The spatial distribution of wrinkle ridges indicates lava plains of unit HNr (older ridged plains material) and Hr (younger ridged plains material) were emplaced before the rise of Tharsis, whereas Hsl (flows of lower member) and Hsu (upper member) were emplaced after Tharsis uplift was initiated. We show that the magma composition differed in the lava plains of STB after the uplift of Tharsis. This study further characterizes early martian magma composition and evolution.

This paper is based on previous quantum encryption proposed by researchers developing a scheme for cryptography using symmetric keys. This study has pointed out that the scheme consists of a pitfall that could lead to a controlled-NOT (CNOT) extraction attack. A malicious user can obtain the secret message of a sender without being detected by using a sequence of single photons and a controlled-NOT gate.