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Li-S batteries have been recognized as one of the most promising candidates for next-generation energy storage systems, however, their practically commercialized applications are severely hindered by the shuttle effect of lithium polysulfides (LiPSS), retarded conversion kinetics and the growth of lithium dendrites. Herein, a vertically growing layered NiFe-LDH derived Ni4N-Fe2N heterostructure cross-like nanoarrays on a carbon cloth (CC) (denoted as CC@Ni4N-Fe2N@C) was constructed by a pot of hydrothermal method followed by the subsequent carbon coating and nitridation processes to synchronously tackle the above challenges related to Li-S batteries. This heterostructure presents good sulfiphilic and lithiophilic properties and can be directly used as the host materials both for S and Li. As-expected, this heterostructure exhibits the significantly improved discharge specific capacity, rate performance and cycle stability compared with the single-metal nitrides (CC@Ni4N@C and CC@Fe2N@C). The study of the symmetric cells certifies that this heterostructure can expose the abundant lithiophilic active sites to achieve the homogeneous Li deposition and effectively suppress the growth of Li dendrites.

Based on the generalized coupled nonlinear Schrödinger equation, we obtain the analytic four-bright–bright soliton solution by using the Hirota bilinear method. The interactions among four solitons are also studied in detail. The results show that the interaction among four solitons mainly depends on the values of solution parameters; k 1 and k 2 mainly affect the two inboard solitons while k 3 and k 4 mainly affect the two outboard solitons; the pulse velocity and width mainly depend on the imaginary part of ki (i = 1, 2, 3, 4), while the pulse amplitude mainly depends on the real part of ki (i = 1, 2, 3, 4).

Parkinson’s disease (PD) is characterized by pathological spontaneous beta oscillations (13 Hz–35 Hz) often observed in basal ganglia (BG) composed of subthalamic nucleus (STN) and globus pallidus (GPe) populations. From the viewpoint of dynamics, the spontaneous oscillations are related to limit cycle oscillations in a nonlinear system; here we employ the bifurcation analysis method to elucidate the generating mechanism of the pathological spontaneous beta oscillations underlined by coupling strengths and intrinsic properties of the STN–GPe circuit model. The results reveal that the increase of inter-coupling strength between STN and GPe populations induces the beta oscillations to be generated spontaneously, and causes the oscillation frequency to decrease. However, the increase of intra-coupling (self-feedback) strength of GPe can prevent the model from generating the oscillations, and dramatically increase the oscillation frequency. We further provide a theoretical explanation for the role played by the inter-coupling strength of GPe population in the generation and regulation of the oscillations. Furthermore, our study reveals that the intra-coupling strength of the GPe population provides a switching mechanism on the generation of the abnormal beta oscillations: for small value of the intra-coupling strength, STN population plays a dominant role in inducing the beta oscillations; while for its large value, the GPe population mainly determines the generation of this oscillation.

We present a new method of solving the probability distribution for baryons, antibaryons and mesons at the hadronization of constituent quark and antiquark system. The hadronization is governed by the quark combination rule in the quark combination model developed by the Shandong Group. We use the method of the generating function to derive the outcome of the quark combination rule, which is much simpler and easier to be generalized than the original method. Furthermore, we use the formula of the quark combination rule and its generalization to study the property of multiplicity distribution of net-protons. Taking a naive case of quark number fluctuations and correlations at hadronization, we calculate ratios of multiplicity cumulants of final-state net-protons and discuss the potential applicability of quark combination model in studying hadronic multiplicity fluctuations and the underlying phase transition property in relativistic heavy-ion collisions., 17 pages, 3 figures. To be published in Chinese Physics C

Development of nanoparticles with multi-functionalities is of great importance. In this study, praseodymium sulfide (Pr2S3) and molybdenum sulfide (MoS2) nanoparticles were synthesized. The structural, morphological and optical properties of the as-obtained products were investigated by XRD, XPS, TEM, UV–vis-NIR spectroscopy, and photoluminescence spectroscopy. Pr2S3 is found to be used in selective photodegradation of fluorescein sodium salt. MoS2 can be utilized for selective photodegradation of rhodamine B. In the mixture of rhodamine B, fluorescein sodium salt and rhodamine 6 G, most of rhodamine B and part of fluorescein sodium salt are optically degraded by Pr2S3. In the mixture of rhodamine B, fluorescein sodium salt and rhodamine 6 G, part of fluorescein sodium salt and most of rhodamine B is degraded by MoS2. Moreover, they emit near-infrared fluorescence (800–1100 nm) when excited by the 785 nm light. Deep tissues imaging with high-contrast is shown, utilizing a nanoparticle-filled centrifuge tube covered with animal tissues (pig Bacon meat). Maximum imaging depth below the tissue surface of 1 cm is achieved. Our work provides a rapid yet efficient procedure to make nanoparticles for dual-application-potential in dye-photodegradation and near-infrared deep tissue imaging.

In this thesis, the thermal aging behaviour at 130°C, 145°C and 160°C for 220kV cable joint EPDM insulation was investigated. The tensile strength and elongation of EPDM insulation both before and after the thermal-oxidative aging were measured, and the microstructure of materials was observed by SEM. The microstructure observation showed that pores formed and expanded into pieces inside the EPDM insulation with thermal aging course, the cracks would appear at the end of aging process. Both tensile strength and elongation of EPDM insulation decreased with aging process lasting, and decreased more gradually with increasing aging temperature. The tensile strength was more sensitive than elongation for aging process. The results can provide theoretical support for the fabrication, operating and maintenance for EPDM cable joint.

We show that the spectra of and at midrapidity in the inelastic events in collisions at 13 TeV exhibit a constituent quark number scaling property, which is a clear signal of quark combination mechanism at hadronization. We use a quark combination model with equal velocity combination approximation to systematically study the production of identified hadrons in collisions at = 13 TeV. The midrapidity spectra for protons, , , , and in the inelastic events are simultaneously fitted by the model. The multiplicity dependence of the yields of these hadrons are also well understood. The strong dependence of the ratio is well explained by the model, which further suggests that the production of two hadrons with similar masses is determined by their quark content at hadronization. The spectra of strange hadrons at midrapidity in different multiplicity classes in collisions at 13 TeV are predicted for further tests of the model. The midrapidity spectra of soft ( GeV/c) strange quarks and up/down quarks at hadronization in collisions at 13 TeV are extracted.

The new methods of optimization of chromaticity for IPS mode have been presented. We have investigated the effect of the alignment angle on the panel chromaticity base on a new photo alignment material composition. The chromaticity of panel also can be improved by optimizing the angle between LC initial orientation and pixel metal electrode for red, green and blue pixel, respectively.

The influences of indium doping on dynamics of 〈a〉-prismatic edge dislocation along [Formula: see text] shuffle plane in wurtzite GaN have been investigated employing classical molecular dynamics (MD) simulations. The dependence of dislocation motion mode and dislocation velocity on indium doping concentration, temperature, and applied shear stress was clarified. Moreover, the simulation results were further analyzed using elastic theory of dislocation and thermal activation theory of dislocation motion, showing excellent agreement with the simulation. Our findings help gain deep insights into modifying dynamic behaviors of TDs through the alloying doping and offer generic tools to the study of other wurtzite materials of promising application prospects, such as AlGaN and ZnO.

We demonstrate the improvement in the efficiency of planar heterojunction perovskite solar cells by employing cadmium selenide tetrapods (CdSe TPs) as an electron extraction layer. The insertion of the CdSe TP layer between the titanium oxide (TiO2) and perovskite film facilitates electron transfer at the TiO2/perovskite interface, as indicated by the significantly quenched steady-state photoluminescence of the perovskite film. Furthermore, we observed a conductivity enhancement of the perovskite film by introducing the CdSe TP layer. The combination of both effects induced by the TPs leads to enhancement in the carrier extraction as well as decreased recombination losses in the perovskite solar cells. As a result, an efficiency of 13.5% (1 sun condition) is achieved in the perovskite solar cells that incorporate the CdSe TP layer, which is 10% higher than that of the device without the CdSe TP layer.

Perovskite photovoltaic cells (PVs) and their tandem application with silicon PVs are strong candidates for low-cost energy harvesting device. To utilize efficient perovskite-based tandem devices, parasitic absorption from buffer layers should be minimized. Here, we demonstrated an infrared (IR)-transparent perovskite PV employing ultra-thin buffer layers. Since vacuum-deposited layers follow underlying structure, thermally evaporated thin buffer layer ( 1 eV) compared to active layer. Moreover, as a result of reduced parasitic absorption, the transmittance of device with thin buffer layers is over 80% at near IR region (800–1100 nm), which allows low energy photons to penetrate top cell of tandem device. The engineering of a top perovskite PV and stacking it with commercialized silicon PVs lead to 19.4% (four-terminal) efficient tandem devices.

The microtubes made through rolling-up of strain-engineered nanomembranes have received growing research attention after their first invention due to the technology's high flexibility, integrability, and versatility. These rolled-up microtubes have been used for a variety of device applications including sensors, batteries and transistors, among others. This paper reports the development of highly sensitive whispering-gallery mode (WGM) chemical sensors based on rolled-up microtube optical microcavities (RUM-OCs). For the first time, such microcavities were batch fabricated through rolling-up of plasma-enhanced chemical vapor deposition (PECVD)-synthesized SiO x /SiN x bilayer nanomembranes, which have better optical properties than the conventional electron-beam-deposited SiO/SiO2 bilayers. Benefiting from the high refractive index (RI) of PECVD-deposited SiN x , our RUM-OC shows an enhanced quality factor of 880 that is much higher than that (50) of a SiO/SiO2 RUM-OC with the same dimensions. The developed RUM-OC is used for sensitive WGM solvent sensing, and demonstrate a limit of detection of 10-4 refractive index unit (RIU), which is 10 times lower than that (10-3 RIU) of a SiO/SiO2 RUM-OC.

The q-deformed entangled states are introduced by using deformation quantization methods and new normal ordering of the vacuum projection operator for q-deformed boson oscillator. In similar way, by virtue of the technique of integration within an ordered product (IWOP) of operators, the new completeness and orthogonality relations composed of the bra and ket, which are not mutually Hermitian conjugates are obtained. Furthermore, the property of squeezing operator represented by the q-deformed entangled states is exhibited. Lastly, the nonclassical properties of the q-deformed two-mode squeezed vacuum state are studied.

Dopamine was polymerized and decorated on surface of the hexagonal boron nitride (h-BN) to enhance the dispersibility and reactivity of h-BN. The polydopamine-decorated BN nanosheets were identified by Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. BN-based nanocomposites were prepared by curing reaction of epoxy E44, Jeffamine D-230 and polydopamine-decorated BN nanosheets. The thermal, mechanical and wear-resistant performance for nanocomposites with different BN loadings (0.5%, 1%, 2%, 4%) were characterized via thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and tribological tests. Results of thermal analysis showed that all BN-based composites possessed the superior thermal stability compared with the pure epoxy resin. The preferable mechanical and wear resistant performance of composites were attributed to the complementary role of mechanical, lubrication and thermal conductivity of BN nanosheets.

Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions. Jansen’s neural mass model (NMM) was initially proposed to study the origin of alpha oscillations. Most of previous studies of the spontaneous alpha oscillations in the NMM were conducted using numerical methods. In this study, we aim to propose an analytical approach using the describing function method to elucidate the spontaneous alpha oscillation mechanism in the NMM. First, the sigmoid nonlinear function in the NMM is approximated by its describing function, allowing us to reformulate the NMM and derive its standard form composed of one nonlinear part and one linear part. Second, by conducting a theoretical analysis, we can assess whether or not the spontaneous alpha oscillation would occur in the NMM and, furthermore, accurately determine its amplitude and frequency. The results reveal analytically that the interaction between linearity and nonlinearity of the NMM plays a key role in generating the spontaneous alpha oscillations. Furthermore, strong nonlinearity and large linear strength are required to generate the spontaneous alpha oscillations.

This study proposed a novel highly anisotropic surface plasmon resonance (SPR) biosensor employing emerging 2D black phosphorus (BP) and graphene atomic layers. Light absorption and energy loss were well balanced by optimizing gold film thickness and number of BP layers to generate the strongest SPR excitation. The proposed SPR biosensor was designed by the phase-modulation approach and is more sensitive to biomolecule bindings, providing 3 orders of magnitude higher sensitivity than the red-shift in SPR angle. Our results show the optimized configuration was 48 nm Au film coated with 4-layer BP crystal to produce the sharpest phase variation (up to 89.8975°), and lowest minimum reflectivity (1.9119 × 10−7). Detection sensitivity up to 7.4914 × 104 degree/refractive index unit is almost 4.5 times enhanced compared to monolayer graphene-based SPR sensors with 48 nm Au film. The anisotropic BP layers act as a polarizer, so the proposed SPR biosensor would exhibit optically tunable detection sensitivity, making it a promising candidate for exploring highly anisotropic platforms in biosensing.

The essay is based on the subject research between Hainan and Tai league, by analyzing the comparison of agricultural development between Hainan and other Chinese areas, finds that Hainan agricultural develops slowly. Meanwhile, by using the experience and technology of Taiwan agricultural development for reference, taking full advantage of modern internet technology, we try to find the complementary opportunity of agricultural technology, experience in agricultural development between Hainan and Taiwan. Therefore, by combining the existing resources of Hainan and Taiwan, following the thoughts of the "Internet+ Agriculture", the essay tries to work out an innovative designation of agricultural cross-border e-commerce management platform, integrate the resource advantages of Hainan and Taiwan, specify the functions of newly designed management platform.

Generalized-stacking-fault energy (GSFE) serves as an important metric that prescribes dislocation behaviors in materials. In this paper, utilizing first-principle calculations and chemical bonding analysis, we studied the behaviors of generalized stacking fault in graphene and h-BN. It has been shown that the π bond formation plays a critical role in the existence of metastable stacking fault (MSF) in graphene and h-BN lattice along certain slip directions. Chemical functionalization was then proposed as an effective means to engineer the π bond, and subsequently MSF along dislocation slips within graphene and h-BN. Taking hydrogenation as a representative functionalization method, we demonstrated that, with the preferential adsorption of hydrogen along the slip line, π electrons along the slip would be saturated by adsorbed hydrogen atoms, leading to the moderation or elimination of MSF. Our study elucidates the atomic mechanism of MSF formation in graphene-like materials, and more generally, provides important insights towards predictive tuning of mechanic properties in two-dimensional nanomaterials.

The present work presents a quantitative modeling framework for investigating the self-rolling of nanomembranes under different lattice mismatch strain anisotropy. The effect of transverse mismatch strain on the roll-up direction and curvature has been systematically studied employing both analytical modeling and numerical simulations. The bidirectional nature of the self-rolling of nanomembranes and the critical role of transverse strain in affecting the rolling behaviors have been demonstrated. Two fabrication strategies, i.e., third-layer deposition and corner geometry engineering, have been proposed to predictively manipulate the bidirectional rolling competition of strained nanomembranes, so as to achieve controlled, unidirectional roll-up. In particular for the strategy of corner engineering, microfabrication experiments have been performed to showcase its practical application and effectiveness. Our study offers new mechanistic knowledge towards understanding and predictive engineering of self-rolling of nanomembranes with improved roll-up yield.

The rapidity and transverse momentum spectra for identified hadrons in central Au+Au collisions at $\sqrt{s_{NN}}= 200$ GeV are computed in a quark combination model. The data of rapidity distributions for $\pi^{\pm}$, $K^{\pm}$, $p(\bar{p})$ and net protons $(p-\bar{p})$ are well described. We also predict rapidity distributions for $K^{0}_{s}$, $\Lambda(\bar{\Lambda})$, $\mathrm{\Xi^{-}}$ ($\mathrm{\bar{\Xi}^{_+}}$) and $\mathrm{\Omega^{-}}+\mathrm{\bar{\Omega}}^{_+}$. The multiplicity ratios of charged antihadrons to hadrons as a function of rapidity are reproduced. The results for ${p}_{T}$ spectra of $\pi^{\pm}$, $K^{\pm}$, $p(\bar{p})$ and for the $p/\pi$ ratios in a broader ${p}_{T}$ range agree well with the data. Finally the rapidity dependence of transverse momentum distributions for hadrons are given.

A semicrystalline composite, 3, 4, 9, 10 perylenetetracarboxylic dianhydride (PTCDA) doped N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), has been fabricated and characterized. An organic light-emitting diode using such a composite in hole injection exhibits the improved performance as compared with the reference device using neat NPB in hole injection. For example, at a luminance of 2000 cd/m(2), the former device gives a current efficiency of 2.0cd/A, higher than 1.6cd/A obtained from the latter device. Furthermore, the semicrystalline composite has been shown thermally to be more stable than the neat NPB thin film, which is useful for making organic light emitting diodes with a prolonged lifetime.

Organic light emitting diodes employing magnesium doped electron acceptor 3, 4, 9, 10 perylenetetracarboxylic dianhydride (Mg: PTCDA) as electron injection layer and silver as cathode were demonstrated. As compared to Mg: Ag cathode, the combination of the Mg: PTCDA layer and silver provided enhanced electron injection into tris (8-quinolinolato) aluminium. The device with 1: 2 Mg: PTCDA and Ag showed an increase of about 12% in the maximum current efficiency, mainly due to the improved hole-electron balance, and an increase of about 28% in the maximum power efficiency, as compared to the control device using Mg: Ag cathode. The properties of Mg: PTCDA composites were studied as well.

The effects of two different types of rounded corner on the performance (such as the insertion loss, the polarization dependent loss (PDL) and the chromatic dispersion) of an echelle diffraction grating (EDG) demultiplexer are analysed by using an accurate method of moment (MoM). The results show that both the insertion loss and the chromatic dispersion increase rapidly as the radius of rounded corners increases. It is shown that the impact of rounded troughs on the PDL is more significant than that of rounded crests. The PDL of an EDG demultiplexer can be reduced near the central wavelength at some special values for the radius of the rounded corners.

Based on Dirac's representation theory and the technique of integration within an ordered product of operators, we put forward the joint wavelet—fractional Fourier transform in the context of quantum mechanics. Its corresponding transformation operator is found and the normally ordered form is deduced. This kind of transformation may be applied to analyzing and identifying quantum states.

Low-frequency flicker noise is usually associated with material defects or imperfection of fabrication procedure. Up to now, there is only very limited knowledge about flicker noise of the topological insulator, whose topologically protected conducting surface is theoretically immune to back scattering. To suppress the bulk conductivity we synthesize antimony doped Bi2Se3 nanowires and conduct transport measurements at cryogenic temperatures. The low-frequency current noise measurement shows that the noise amplitude at the high-drain current regime can be described by Hooge's empirical relationship, while the noise level is significantly lower than that predicted by Hooge's model near the Dirac point. Furthermore, different frequency responses of noise power spectrum density for specific drain currents at the low drain current regime indicate the complex origin of noise sources of topological insulator.

Single crystals of ZnAl2Se4-4xS4x quaternary solid solution were grown by the chemical transport reaction method. The ZnAl2Se4-4xS4x single crystals were found to have a defect chalcopyrite structure in the region of 0.0≤x≤0.2 and a cubic spinel in the region of 0.8≤x≤1.0. It was also shown in these regions that the lattice constants and optical energy gaps depend on a composition x. A miscibility region existed in the region of 0.2

MgAl2Se4, MgAl2Se4:Co2+, CaAl2Se4 and CaAl2Se4:Co2+ single crystals were grown by the chemical transport reaction method in a closed system using iodine as a transport agent. The MgAl2Se4 and MgAl2Se4:Co2+ single crystals crystallized into a hexagonal (rhombohedral) structure, and the CaAl2Se4 and CaAl2Se4:Co2+ single crystals crystallized into an orthorhombic structure. The optical energy gaps of the MgAl2Se4, MgAl2Se4:Co2+, CaAl2Se4 and CaAl2Se4:Co2+ single crystals at 10 K were found to be 3.286 eV, 2.596 eV, 3.823 eV and 3.082 eV, respectively. The impurity optical absorption peaks were observed in the MgAl2Se4:Co2+ and CaAl2Se4:Co2+ single crystals and analysed to appear as a result of the electron transitions between energy levels of the Co2+ ion in sites of Td symmetry.

MgAl2S4, CaAl2S4, MgAl2S4:Er3+ and CaAl2S4:Er3+ single crystals were grown by the chemical transport reaction method. The single crystals crystallized in an orthorhombic structure. The single crystals had the direct energy band structure and their optical energy gaps were 4.334 eV, 4.213 eV, 4.835 eV and 4.716 eV for the MgAl2S4, MgAl2S4:Er3+, CaAl2S4, and CaAl2S4:Er3+ single crystals, respectively, at 13 K. Sharp emission peaks appeared in the MgAl2S4:Er3+ and CaAl2S4:Er3+ single crystals, and they were interpreted to originate from the Er3+ ion substituted Mg2+ and Ca2+ ions in the MgAl2S4:Er3+ and CaAl2S4:Er3+ single crystals.

and single crystals were grown by the closed tube sublimation method. The crystal structures and the composition dependence of the energy gaps of the single crystals were identified, and the impurity optical absorption in the single crystals were investigated. The origin of the impurity optical absorption was identified with electron transitions between the energy levels of the ion sited at the symmetry point.

Organic light emitting diodes with an interface of organic acceptor 3-, 4-, 9-, 10-perylenetetracarboxylic dianhydride (PTCDA) and donor copper phthalocyanine (CuPc) involved in hole injection are fabricated. As compared to the conventional device using a 5 nm CuPc hole injection layer, the device using an interface of 10 nm PTCDA and 5 rim CuPc layers shows much lower operating voltage with an increase of about 46% in the maximum power efficiency. The enhanced device performance is attributed to the efficient hole generation at the PTCDA/CuPc interface. This study provides a new way of designing hole injection.

We present the pretilt control of a nematic liquid crystal (LC) on polymer layers exposed to a plasma beam under atmospheric pressure. Depending on the exposure parameters of the atmospheric pressure plasma (APP) in a sheetlike shape, the vertical or the planar alignment with a variable pretilt can be produced on a homeotropic polyimide (PI) layer. The polar anchoring energy of the APP-exposed PI layer is of the order of 10-4 J/m2, comparable to the rubbed PI layer. Our approach to the plasma-assisted LC alignment under ambient pressure would be applicable for the in-line process of producing wideviewing LC displays with multidomains.

This paper reports the induced growth of high quality ZnO thin film by crystallized amorphous ZnO. Firstly amorphous ZnO was prepared by solid-state pyrolytic reaction, then by taking crystallized amorphous ZnO as seeds (buffer layer), ZnO thin films have been grown in diethyene glycol solution of zinc acetate at 80°C. X-ray Diffraction curve indicates that the films were preferentially oriented [001] out-of-plane direction of the ZnO. Atomic force microscopy and scanning electron microscopy were used to evaluate the surface morphology of the ZnO thin film. Photoluminescence spectrum exhibits a strong ultraviolet emission while the visible emission is very weak. The results indicate that high quality ZnO thin film was obtained.

Atomistic simulations using molecular dynamics (MD) are emerging as a valuable tool for exploring dissipation and material damping in nanomechanical resonators. In this study, we used isothermal MD to simulate the dynamics of the longitudinal-mode oscillations of an amorphous silicon nanoresonator as a function of frequency (2 GHz–50 GHz) and temperature (15 K–300 K). Damping was characterized by computing the loss tangent with an estimated uncertainty of 7%. The dissipation spectrum displays a sharp peak at 50 K and a broad peak at around 160 K. Damping is a weak function of frequency at room temperature, and the loss tangent has a remarkably high value of ~0.01. In contrast, at low temperatures (15 K), the loss tangent increases monotonically from to as the frequency increases from 2 GHz to 50 GHz. The mechanisms of dissipation are discussed.

Based on Fermi's golden rule and the theory of Boltzmann collision term approximation, the hole scattering mechanism related to stress and orientation in Si-based strained materials was studied in-depth. The results show that: (1) the total hole scattering rates in Si-based strained materials decrease obviously under strain; (2) the turn is Si/(111)Si1−xGex > Si/(101)Si1−xGex > Si1−xGex/(111)Si > Si1−xGex/(101)Si > Si/(001)Si1−xGex > Si1−xGex/(001)Si when Ge fraction is about 0.2; (3) the decreasing total hole scattering rates of in strained materials with the increasing stress is mainly caused the decreasing acoustic phonon scattering rate under strain. The theoretical conclusions obtained could provide important references for researching the hole mobility and the understanding of Si-based materials or other physical strained materials.