Determining the strange and antistrange quark distributions of the nucleon

The difference between the strange and antistrange quark distributions,δs（x） = s（x） ˉs（x）,and the combination of light quark sea and strange quark sea,Δ（x） =ˉ d（x） ＋ uˉ（x） s（x） ˉs（x）,are originated from non-perturbative processes and can be calculated using non-perturbative models of the nucleon.We report calculations of δs（x） and Δ（x） using the meson cloud model.Combining our calculations of Δ（x） with relatively well known light antiquark distributions obtained from global analysis of available experimental data,we estimate the total strange sea distributions of the nucleon.     

Analyses of temperature-dependent interface states,series resistances,and AC electrical conductivities of Al/p Si and Al/Bi_4Ti_3O_(12)/p Si structures by using the admittance spectroscopy method

In this study, Al/p-Si and Al/Bi4Ti3O12/p-Si structures are fabricated and their interface states （Nss）, the values of series resistance （Rs）, and AC electrical conductivity （σac） are obtained each as a function of temperature using admit- tance spectroscopy method which includes capacitance-voltage （C-V） and conductance-voltage （G-V） measurements. In addition, the effect of interfacial Bi4Ti3012 （BTO） layer on the performance of the structure is investigated. The voltage- dependent profiles of Nss and Rs are obtained from the high-low frequency capacitance method and the Nicollian method, respectively. Experimental results show that Nss and Rs, as strong functions of temperature and applied bias voltage, each exhibit a peak, whose position shifts towards the reverse bias region, in the depletion region. Such a peak behavior is attributed to the particular distribution of Nss and the reordering and restructuring of Nss under the effect of temperature. The values of activation energy （Ea）, obtained from the slope of the Arrhenius plot, of both structures are obtained to be bias voltage-independent, and the Ea of the metal-ferroelectric-semiconductor （MFS） structure is found to be half that of the metal-semiconductor （MS） structure. Furthermore, other main electrical parameters, such as carrier concentration of acceptor atoms （NA）, built-in potential （Vbi）, Fermi energy （EF）, image force barrier lowering （△φb）, and barrier height （φb）, are extracted using reverse bias C 2-V characteristics as a function of temperature.     

Calculation of Equation of State of QCD at Finite Chemical Potential and Temperature

In this paper, using path integral techniques we derive a model-independent formula for the pressure density P（μ, T） （or equivalently the partition function） of Quantum Chromodynamics （QCD）, which gives the equation of state （EOS） of QCD at finite chemical potential and temperature. In this formula the pressure density P（μ, T） consists of two terms： the first term （p（μ, T）｜T=0） is a μ-independent （but T-dependent） constant; the second term is totally determined by G[μ, T]（p, ωn） （the dressed quark propagator at finite μ and finite T）, which contains all the nontrivial μ-dependence. Then, in the framework of the rainbow-ladder approximation of the Dyson-Schwinger （DS） approach and under the approximation of neglecting the μ-dependence of the dressed gluon propagator, we show that G[μ, T]（p,ωn） can be obtained from G[T]（p,ωn ） （the dressed quark propagator at μ= 0） by the substitution ωn →ωn ＋ iμ. This result facilitates numerical calculations considerably. By this result, once C [T] （p, ωn） is known, one can determine the EOS of QCD under the above approximations （up to the additive term p（μ, T）｜T=0）. Finally, a comparison of the present EOS of QCD and the EOS obtained in the previous literatures in the framework of the rainbow-ladder approximation of the DS approach is given. It is found that the EOS given in the previous literatures does not satisfy the thermodynamic relation ρ（μ,T） =δp（μ,T）/δμ｜T.     

Energetic Evolution of Single-Crystalline ZnO Nanowires and Nanotubes

We report the formation energies of wurtzite zinc oxide （w-ZnO） nanowires （NWs） and nanotubes （NTs） with faceted morphologies, and show that hexagonal NWs （h-NWs） are energetically advantageous over the NWs with rhombic （r-）, squared （s-）, and triangular （t-） cross sections. The formation energies of h-NWs are proportional to the inverse of wire radius, whereas those of single-crystalline NTs are proportional to the inverse of wall thickness, irrespectively to tube radius. A simple model is presented to interpret these features.     

Increased performance of an organic light-emitting diode by employing a zinc phthalocyanine based composite hole transport layer

We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine （ZnPc）-based composite hole transport layer （c-HTL）. The optimum ris-（8-hydroxyquinoline）aluminum （Alq3）-based organic light-emitting diode with a c-HTL exhibits a lower turn-on voltage of 2.8 V, a higher maximum current efficiency of 3.40 cd/A and a higher maximum power efficiency of 1.91 lm/W, which are superior to those of the conventional device （turn-on voltage of 3.8 V, maximum current efficiency of 2.60 cd/A, and maximum power efficiency of 1.21 lm/W）. We systematically studied the effects of different kinds of N’-diphenyl-N,N’-bis（1-naphthyl）（1,1’-biphenyl）-4,4’diamine （NPB）：ZnPc c-HTL. Meanwhile, we also investigate their mechanisms different from that in the case of using ZnPc as buffer layer. The specific analysis is based on the absorption spectra of the hole transporting material and current density–voltage characteristics of the corresponding hole-only devices.     

Strange K^- nuclear systems （S=-1）

Λ（1405） is considered as a superposition of two resonances instead of a simple bound state of the kaon and proton. Within the framework of the Brueckner-Hartree-Fock（BHF） theory, we have investigated the K^- nuclear systems （S = -1）, especially K^-pp and K^-pnn（T = 1）. The binding energy BK- is 23 MeV （3 MeV） and the width Γ is 62 MeV （56 MeV） for K^-pp（K^-pnn（T =1））.     

Multi-types of Skyrmions in SU（N） Quantum Hall System

The skyrmions in SU（N） quantum Hall （QH） system are discussed. By analyzing the gauge field structure and the topological properties of this QH system it is pointed out that in the SU（N） QH system there can exist （N-1） types of skyrmion structures, instead of only one type of skyrmions. In this paper, by means of the Abelian projections according to the （N - 1） Cartan subalgebra local bases, we obtain the （N - 1） U（1） electromagnetic field tensors in the SU（N） gauge field of the QH system, and then derive （N - 1） types of skyrmion structures from these U（1） sub-field tensors. Furthermore, in light of the C-mapping topological current method, the topological charges and the motion of these skyrmions are also discussed.     

Ultrashort pulse breaking in optical fiber with third-order dispersion and quintic nonlinearity

The optical wave breaking （OWB） characteristics in terms of the pulse shape, spectrum, and frequency chirp, in the normal dispersion regime of an optical fiber with both the third-order dispersion （TOD） and quintic nonlinearity （QN） are numerically calculated. The results show that the TOD causes the asymmetry of the temporal- and spectral-domain, and the chirp characteristics. The OWB generally appears near the pulse center and at the trailing edge of the pulse, instead of at the two edges of the pulse symmetrically in the case of no TOD. With the increase of distance, the relation of OWB to the TOD near the pulse center increases quickly, leading to the generation of ultra-short pulse trains, while the OWB resulting from the case of no TOD at the trailing edge of the pulse disappears gradually. In addition, the positive （negative） QN enhances （weakens） the chirp amount and the fine structures, thereby inducing the OWB phenomena to appear earlier （later）. Thus, the TOD and the positive （negative） QN are beneficial （detrimental） to the OWB and the generation of ultra-short pulse trains.     

Reduced Properties and Applications of Y（sl（2）） Algebra for a Two-Spin System

By taking a special constraint for a general realization of Y（sl（2））, two sets of sl（2） algebras are presented, in which a u（1） algebra is hidden. With the help of this constraint, the block-diagonal form can be written to the generator J of Yangian algebras, and especially it is a rotational transformation of a spin in the elementary quantum mechanics. This sheds new light on the physical meaning of Y （sl（2） ）.     

Description of the Structural Properties of Low-Lying States in ^102Ru with IBM2

We describe the properties of low-lying states of ^102Ru within the framework of the proton-neutron interacting model IBM2. The theoretical predictions of the ground state, quasi-γ and quasi-β bands, and the ratios of the B（E2） transition strengths are reproduced very well. The structural properties of ^102Ru are identified in the parameters space of the interacting boson model （IBM2）. The characteristic feature of the energy spectrum structure exhibits that ^102Ru is very close to the critical point of Uπv（5）-Oπv（6） transition and towards Uπv（5） symmetry. The key sensitive quantities of the B（E2） branching ratio clearly indicate that ^102Ru is a primary Oπv（6） symmetry, while with a somewhat Uπv（5） symmetry. It is possible that the shape coexistence persists in ^102Ru, whereas the evident fingerprint of the shape coexistence has not been observed.     

Unique Magnetic Moment and Electronic Properties for Fe（MgO）n（n=1-8） Clusters： First-Principles Calculations

The geometries and electronic properties of Fe（MgO）n are systematically investigated by the density functional theory. The results show that the doped Fe atom is prone to bond with the O atom, and Fe almost does not disturb the frame of （MgO）n. The second-order energy difference, the fragmentation energies and the electron amnities show that Fe（MgO）4 and Fe（MgO）6 possess relatively higher stabilities. The HOMO-LUMO gaps of Fe（MgO）n decrease obviously as compared with （MgO）n. Almost equal unpaired electrons of the 3d state of the Fe atom in Fe（MgO）n result in a nearly equal magnetic moment of Fe（MgO）n.     

An Interacting Gauge Field Theoretic Model for Hodge Theory: Basic Canonical Brackets

We derive the basic canonical brackets amongst the creation and annihilation operators for a two （1 ＋ 1）- dimensional （2D） gauge field theoretic model of an interacting Hodge theory where a U（1） gauge field （Aμ） is coupled with the fermionic Dirac fields （ψ and ψ）. In this derivation, we exploit the spin-statistics theorem, normal ordering and the strength of the underlying six infinitesimal continuous symmetries （and the concept of their generators） that are present in the theory. We do not use the definition of the canonical conjugate momenta （corresponding to the basic fields of the theory） anywhere in our whole discussion. Thus, we conjecture that our present approach provides an alternative to the canonical method of quantization for a class of gauge field theories that are physical examples of Hodge theory where the continuous symmetries （and corresponding generators） provide the physical realizations of the de Rham cohomological operators of differential geometry at the algebraic level.     

Growth of Highly Conductive n-Type Al0.7Ga0.3N Film by Using AlN Buffer with Periodical Variation of Ⅴ/Ⅲ Ratio

High quality and highly conductive n-type Al0.7Ga0.3N films are obtained by using AlN multi-step layers （MSL） with periodical variation of Ⅴ/Ⅲ ratios by low-pressure metalorganic chemical vapour deposition （LP-MOCVD）. The full-width at half-maximum （FWHM） of （0002） and （1015） rocking curves of the Si-doped Al0.7Ga0.3N layer are 519 and 625 arcsec, respectively, Room temperature （RT） Hall measurement shows a free electron concentration of 2.9 × 10^19 cm^-3, and mobility of 17.8cm^2V^-1s^-1, corresponding to a resistivity of 0.0121 Ω cm. High conductivity of the Si-doped AlGaN film with such high Al mole fraction is mainly contributed by a remarkable reduction of threading dislocations （TDs） in AlGaN layer. The TD reducing mechanism in AlN MSL growth with periodical variation of Ⅴ/Ⅲ ratio is discussed in detail.     

X-shape oligo（thiophene）s as donor materials for vacuum-deposited organic photovoltaic cells

The films of two x-shape oligo（thiophene）s, 3, 4-dibithienyl-2, 5-dithienylthiophene （7T） and 2, 5-dibithienyl-3, 4- ditrithienylthiophene （11T）, which are prepared by vacuum evaporation, have been investigated as novel electron donor layers in two-layer photovoltaic cells. UV-Vis absorptions show red-shifted and broadened absorptions of the vacuumevaporated films as compared with those of the corresponding solutions and spin-coating films, which is beneficial for photovoltaic properties. X-ray diffraction （XRD） and differential scanning calorimetry （DSC） measurements show that the vacuum-evaporated films are almost amorphous. Two-layer photovoltaic cells have been realized by the thermal evaporation of 7T and llT as donors and N, N′-bis（1-ethylpropyl）-3, 4：9,10-perylene bis（tetracarboxyl diimide） （EP- PTC） as an acceptor. An energy conversion efficiency （ECE） of 0.18% of the cell based on 7T with an irradiation of white light at 100 mw/cm^2 has been demonstrated by the measurements of current （I）- voltage （V） curves of the cells to be higher than the ECE of the reference system based on donor dihexylterthienyl （H3T） that is linear and without α, β linkage.     

Resonant Third-Order Optical Nonlinearities of Poly（methyl methacrylate） Films Containing J-Like Aggregates of a Thiadicarbocyanine Dye

The third-order optical nonlinearities and responses of poly（methyl methacrylate） （PMMA） coating films containing J-like aggregates of a thiadicarbocyanine dye, 3,3＇-diethyl-2,2＇-thiadicarbocyanine iodide （DTDC1）, are measured by degenerate four-wave mixing （DFWM） technique under resonant conditions. The temporal profiles of the DFWM signal of PMMA coating films containing J-like aggregates of DTDC1 are found to consist of three components： i.e., the coherent instantaneous nonlinear response （electronic response） and the two slow responses uqth decay time constants of about 0.8ps and about 7.0ps. The electronic component of the effective third-order nonlinear susceptibility, χc^（3）, of one of the present films is as high as about 2.1×10^-8 esu, and the figure of merit of third-order nonlinearity F （F=χ^（3）/α） is evaluated to be about 1.9 ×10^-13 esu cm at 850nm.     

Polymer White-Light-Emitting Diodes with High Work Function Cathode Based on a Novel Phosphorescent Chelating Copolymer

Polymer white-light-emitting diodes are fabricated based on the blend of poly[9,9-di-（2-ethylhexyl）-fluorenyl-2, 7- diyl]-end capped with polysilsesquioxane （PFO） and a chelating copolymer of poly[（9,9-bis（3′-（N,N-dimethylamino） propyl）-2, 7-fluorene-alt-2, 7-（9,9-dioctylfluorene） ）-co- [2, 7-（9,9-dioctlyfluorene）-alt-5,5-bis（2-（4-methyl-l-naphtha- lene） pyridine-C^2,N） iridium （III） acethylacetonate]] （PFN-NaIr）. The device with the sole aluminium cathode is able to produce a comparably white electroluminescence efficiency of 1.31 cd/A to that of the device using low work function cathodes （such as Ba, Ca, etc.）. The CIE coordinates of the white light emission consisting of red, green and blue three components are nearly at （0.34, 0.35）. The mechanism of the white light emission from the device with the AI cathode is investigated, which is related to the efficient injection of electrons through the interface of PFN-Nalr/AI.     

Weyl Ordering Expansion of Power Product of Coordinate and Momentum Operators

By virtue of the technique of integration within Weyl ordered of operators we derive the formula of Weyl ordering expansion of power product of coordinate and momentum operators （√2Q）^m（√2iP） ^τ=：： Hm,r （√2Q, √2iP）：：, the introduction of two-variable Hermite polynomial Hm,r brings much convenience to the study of Weyl correspondence.     

An Inequality Concerning Quantitative Duality in an Asymmetry Two-Way Interferometer

We reinvestigate the measures concerning the notion of duality of a quantum system （the ＂quanton＂） in an asymmetry two-way interferometer. A new measure of the which-way information is introduced, which is based on the fidelity ~ instead of the trace distance Q of the final states of the which-way detector. An improved inequality is derived to be V2 ≤ （R0^2 -P2）（1 -F）2, which is more stringent than the previous one of V2 ≤ （1 -P2）（1 - Q2）.     

Kinetic Behaviors of a Competitive Population and Fitness System in Exchange-Driven Growth

We proposed an aggregation model of two species aggregates of fitness and population to study the interaction between the two species in their exchange-driven processes of the same species by introducing the monomer birth of fitness catalyzed by the population, where the fitness aggregates perform self-death process and the population aggregates perform self-birth process. The kinetic behaviors of the aggregate size distributions of the fitness and population were analyzed by the rate equation approach with their exchange rate kernel K1（k,j） = K1kj and K2（k,j） = K2kj, the fitness aggregate＇s self-death rate kernel J1 （ k ） = J1 k, population aggregate＇s self-birth rate kernel J2（ k ） = J2k and population-catalyzed fitness birth rate kernel I（k,j） = Ikj＇. The kinetic behavior of the fitness was found depending crucially on the parameter v, which reflects the dependence of the population-catalyzed fitness birth rate on the size of the catalyst （population） aggregate. （i） In the v ≤ 0 case, the effect of catalyzed-birth of fitness is rather weak and the exchange-driven aggregation and self-death of the fitness dominate the process, and the fitness aggregate size distribution αk（t） does not have scale form. （ii） When v ≥0, the effect of the population-catalyzed birth of fitness gets strong enough, and the catalyzed-birth and self-death of the fitness aggregates, together with the self-birth of the population aggregates dominate the evolution process of the fitness aggregates. The aggregate size distribution αk （t） approaches a generalized scaling form.