We propose a linear optical protocol to generate three-photon and four-photon entangled states without resorting to entangled sources. The setup in this protocol is composed of three beam splitters and two half-wave plates. We can obtain three-photon and four-photon entangled states with postselection, as with other protocols. This protocol has the advantage of high efficiency and is more feasible than others.

To explore the influence of anomalous diffusion on stochastic resonance (SR) more deeply and effectively, the method of moments is extended to subdiffusive overdamped bistable fractional Fokker--Planck systems for calculating the long-time linear dynamic response. It is found that the method of moments attains high accuracy with the truncation order N=10, and in normal diffusion such obtained spectral amplification factor (SAF) of the first-order harmonic is also confirmed by stochastic simulation. Observing the SAF of the odd-order harmonics we find some interesting results, i.e. for smaller driving frequency the decrease of subdiffusion exponent inhibits the stochastic resonance (SR), while for larger driving frequency the decrease of subdiffusion exponent enhances the second SR peak, but the first one vanishes and a double SR is induced in the third-order harmonic at the same time. These observations suggest that the anomalous diffusion has important influence on the bistable dynamics.

Cascaded nonlinear phase shifts may be imposed on the interacting waves during second-harmonic generation (SHG) in a quasi-phase-matched (QPM) structure, which are severe in high-intensity regime and may result in lower conversion efficiency. We propose a configuration of QPM structure with reduced domain-length, which may depress the nonlinear phase shifts to some extent and lead to an improvement on the conversion efficiency. The numerical analyses on the conversion efficiency as well as the relative phase angle are discussed in detail for better understanding of the SHG process.

Interfacial chemical structure of HfO₂/Si (100) is investigated using angle-resolved synchrotron radiation photoemission spectroscopy (ARPES). The chemical states of Hf show that the Hf 4f binding energy changes with the probing depth and confirms the existence of Hf--Si--O and Hf--Si bonds. The Si 2p spectra are taken to make sure that the interfacial structure includes the Hf silicates, Hf silicides and SiO_x. The metallic characteristic of the Hf--Si bonds is confirmed by the valence band spectra. The depth distribution model of this interface is established.

High resolution photoemission measurements are carried out on non-superconducting SmOFeAs parent compound and superconducting SmFeAs(O_1-xF_x) (x=0.12, and 0.15) compounds. The momentum-integrated spectra exhibit a clear Fermi cutoff that shows little leading-edge shift in the superconducting state. A robust feature at 13meV is identified in all these samples. Spectral weight suppression near E_F with decreasing temperature is observed in both undoped and doped samples that points to a possible existence of a pseudogap in these Fe-based compounds.

High resolution photoemission measurements are carried out on non-superconducting LaFeAsO parent compound and various superconducting RFeAs(O_1-xF_x) (R=La, Ce and Pr) compounds. It is found that the parent LaFeAsO compound shows a metallic character. By extensive measurements, several common features are identified in the electronic structure of these Fe-based compounds: (1) 0.2eV feature in the valence band, (2) a universal 13--16meV feature, (3) near E_F spectral weight suppression with decreasing temperature. These universal features can provide important information about band structure, superconducting gap and pseudogap in these Fe-based materials.

The ultraviolet emission line at 3.315eV is observed at 8K in ZnO polycrystalline films and investigated by temperature-dependent photoluminescence spectra and cathodoluminescence spatial image. The relative intensity of 3.315eV emission line depends strongly on growth and annealing conditions. The cathodoluminescence image shows that the 3.315eV emission localizes on the surface and ridge of ZnO grain. These results suggest that the 3.315eV emission attributes to Zn interstitials at the grain surface and ridge. This emission is stable in the range from 8K to 300K and contributes to the room temperature ultraviolet band.

High-quality type-IIa gem diamond crystals are successfully synthesized in a Ni₇₀Mn₂₅Co₅-C system by temperature gradient method (TGM) at about 5.5GPa and 1560K. Al and Ti/Cu are used as nitrogen getters respectively. While nitrogen getter Al or Ti/Cu is added into the synthesis system, some inclusions and caves tend to be introduced into the crystals. When Al is added into the solvent alloy, we would hardly gain high-quality type-IIa diamond crystals with nitrogen concentration N_c< 1ppm because of the reversible reaction of Al and N at high pressure and high temperature (HPHT). However, when Ti/Cu is added into the solvent alloy, high-quality type-IIa diamond crystals with N_c < 1ppm can be grown by decreasing the growth rate of diamonds.

We present polyethylene oxide (PEO) functional films polymerized by rf plasma-enhanced vapour chemical deposition (rf-PECVD) on p-Si (100) surface with precursor ethylene glycol dimethyl ether (EGDME) and diluted Ar in pulsed plasma mode. The influences of discharge parameters on the film properties and compounds are investigated. The film structure is analysed by Fourier transform infrared (FTIR) spectroscopy. The water contact angle measurement and atomic force microscope (AFM) are employed to examine the surface polarity and to detect surface morphology, respectively. It is concluded that the smaller duty cycle in pulsed plasma mode contributes to the rich C--O--C (EO) group on the surfaces. As an application, the adsorption behaviour of platelet-rich plasma on plasma polymerization films performed in-vitro is explored. The shapes of attached cells are studied in detail by an optic invert microscope, which clarifies that high-density C--O--C groups on surfaces are responsible for non-fouling adsorption behaviour of the PEO films.

Cylinder-shaped Cu₈₀Ni₂₀ alloy melt is undercooled and solidified by the combination of the electromagnetic levitation technique and the flux treatment method. Nearly constant temperature gradient of 8-10K/cm is realized for the cylindrical melts with different undercooling levels at the bottom ends. The experimental results reveal that with the increase of the undercooling of the melts from 35 to 220K, the microstructures undergo transition from coarse dendrites to granular grains, unidirectional dendrites, and finally to equiaxed grains.

Using standard 0.18-μm CMOS process and the special platform for 8-inch phase change random access memory (PCRAM), the first Chinese 16k bits PCRAM chip has been successfully achieved. A 1R1T structure has been designed for low voltage drop and low cost compared to the 1R1D structure and the BJT-switch structure. Full integration of the 16k bits PCRAM chip, including memory cell, array structure, critical circuit module, and physical layout, has been designed and verified. The critical integration technology of the phase change material (PCM) fabrication and the standard CMOS process has been solved. Test results about PCM in a large-scale array have been generated for the next research of PCRAM chip.

We present an analytical solution for fluid velocity field distribution of polyelectrolyte DNA. Both the electric field force and the viscous force in the DNA solution are considered under a suitable boundary condition. The solution of electric potential is analytically obtained by using the linearized Poisson--Boltzmann equation. The fluid velocity along the electric field is dependent on the cylindrical radius and concentration. It is shown that the electric field-induced fluid velocity will be increased with the increasing cylindrical radius, whose distribution also varies with the concentration

We propose a new concept, two-step degree. Defining it as the capacity of a node of complex networks, we establish a novel capacity--load model of cascading failures of complex networks where the capacity of nodes decreases during the process of cascading failures. For scale-free networks, we find that the average two-step degree increases with the increase of the heterogeneity of the degree distribution, showing that the average two-step degree can be used for measuring the heterogeneity of the degree distribution of complex networks. In addition, under the condition that the average degree of a node is given, we can design a scale-free network with the optimal robustness to random failures by maximizing the average two-step degree.