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We study the long-time average of the reduced density matrix (RDM) of a two-level system as the central system, which is locally coupled to a many-body quantum chaotic system as the environment, under an overall Schrödinger evolution. A phenomenological relation among elements of the RDM is proposed for a dissipative interaction in the strong coupling regime and is tested numerically with the environment as a defect Ising chain, as well as a mixed-field Ising chain.

We study the sensitivity of energy eigenstates to small perturbation in quantum integrable and chaotic systems. It is shown that the distribution of rescaled components of perturbed states in unperturbed basis exhibits qualitative difference in these two types of systems: being close to the Gaussian form in quantum chaotic systems, while, far from the Gaussian form in integrable systems.

Cu2Se is a promising “phonon liquid–electron crystal” thermoelectric material with excellent thermoelectric performance. In this work, Cd-doped Cu2–x SeCd x (x = 0, 0.0075, 0.01, and 0.02) samples were prepared using NaCl flux method. The solubility of Cd in Cu2Se at room temperature was less than 6%, and a second phase of CdSe was found in the samples with large initial Cd content (x = 0.01 and 0.02). Field-emission scanning electron microscopic image showed that the arranged lamellae formed a large-scale layered structure with an average thickness of approximately 100 nm. Transmission electron microscopy demonstrated that doping of Cd atoms did not destroy the crystal integrity of Cu2Se. A small amount of Cd in Cu2Se could reduce the electrical and thermal conductivities of the material, thus significantly enhancing its thermoelectric performance. With the increase in Cd content in the sample, the carrier concentration decreased and the mobility increased gradually. Thermogravimetric differential thermal analysis showed that no weight loss occurred below the melting point. Excessive Cd doping led to the emergence of the second phase of CdSe in the sample, thus significantly increasing the thermal conductivity of the material. A maximum ZT value of 1.67 at 700 K was obtained in the Cu1.9925SeCd0.0075 sample.

Adhesion is a major factor in film failure. Based on the basic theory of interfacial toughness, the relationship between film thickness and internal stress and adhesion is qualitatively analyzed. The adhesive properties of silicon nitride deposited on stainless steel substrate by plasma enhanced chemical vapor deposition methods is discussed. The case where nickel, nickel-chromium and alumina films are respectively used as transition layers is compared. After vacuum annealing thermal treatment of these films, the results show that the alumina film has better matching performance with 304 stainless steel, and the interface toughness is improved by 51.2% compared with the silicon nitride film. After the samples are stretched, the silicon nitride film show a large number of cracks when the transition layer is nickel or nickel-chromium, possibly due to the large thermal stress in the film. At the same time, the process parameters of magnetron sputtered alumina are optimized, and the optimal deposition rate of alumina film is determined to be 40.25 nm min-1. Then, the effect of film thickness on adhesion is investigated by theoretical analysis and tape breakage test. As the film thickness ratio of alumina and silicon nitride increases, the adhesion is optimal.

The environmentally friendly and non-cyanide thiosulfate gold leaching technology was used to extract gold from a low-sulfur gold concentrate. The effect of TEA on leaching of pure gold under the condition of adding quartz indicated that TEA could significant increase the dissolution rates of gold and the mixed solution potentials and decrease the consumption of thiosulfate. Quartz has little effect on the gold leaching process. Moreover, the effect of additive Triethanolamine (TEA) on the gold extraction was further studied. The chemical analysis and process mineralogy analysis of the concentrate indicated that the concentrate contained 59 g/t Au, 64.49% SiO2, 19.55% Al and 5.76% Fe. The concentrate was composed of quartz, muscovite and chlorite as major minerals. Quartz was the main gold-bearing mineral in concentrate. The gold particles of less than 20 μm in the concentrate reached 50.56%. Traditional thiosulfate leaching technology was used to extract gold from the concentrate, and the gold leaching rate was only 44.49% after 48 hours. When 0.024 M (MTEA:Mcopper=2:1) TEA was added in the thiosulfate leaching gold system, the thiosulfate consumption significantly reduced by about 32% and the leaching rate of gold increased to 73.40%.

We introduce a decimation scheme of constructing renormalized Hamiltonian flows, which is useful in the study of properties of energy eigenfunctions, such as localization, as well as in approximate calculation of eigenenergies. The method is based on a generalized Brillouin-Wigner perturbation theory. Each flow is specific for a given energy and, at each step of the flow, a finite subspace of the Hilbert space is decimated in order to obtain a renormalized Hamiltonian for the next step. Eigenenergies of the original Hamiltonian appear as unstable fixed points of renormalized flows. Numerical illustration of the method is given in the Wigner-band random-matrix model.

In-vessel components are important parts of the EAST superconducting tokamak. They include the plasma facing components, passive plates, cryo-pumps, in-vessel coils, etc. The structural design, analysis and related R&D have been completed. The divertor is designed in an up-down symmetric configuration to accommodate both double null and single null plasma operation. Passive plates are used for plasma movement control. In-vessel coils are used for the active control of plasma vertical movements. Each cryo-pump can provide an approximately 45 m3/s pumping rate at a pressure of 10−1 Pa for particle exhaust. Analysis shows that, when a plasma current of 1 MA disrupts in 3 ms, the EM loads caused by the eddy current and the halo current in a vertical displacement event (VDE) will not generate an unacceptable stress on the divertor structure. The bolted divertor thermal structure with an active cooling system can sustain a load of 2 MW/m2 up to a 60 s operation if the plasma facing surface temperature is limited to 1500 °C. Thermal testing and structural optimization testing were conducted to demonstrate the analysis results.

In this paper magnetization remanence curves were studied for nanocrystalline Pr8Fe87B5, Pr12Fe82B6 and Pr15Fe77B8. Initially the sample was at remanence following saturation along z-axis. After rotating the magnet by 5n degrees (n = 0, 1, ..., 18) a field H was applied along z-axis and then decreased to zero, and the remanence Jnr was measured as a function of H. The curves were compared with those calculated based on the nucleation of reverse domain model and domain wall pinning model. The latter model succeeds in simulation much better than the former, and it is concluded that the magnetization reversal is dominated by domain wall pinning for all the samples. The nucleation mechanism contribution, while remains small, increases with the increase of Pr content.

An investigation was conducted into the effect of hydrogen dilution on the microstructure and optical properties of silicon nanograins embedded in silicon nitride (Si/SiNx) thin film deposited by the helicon wave plasma-enhanced chemical vapour deposition technique. With Ar-diluted SiH4 and N2 as the reactant gas sources in the fabrication of thin film, the film was formed at a high deposition rate. There was a high density of defect at the amorphous silicon (a-Si)/SiNx interface and a relative low optical gap in the film. An addition of hydrogen into the reactant gas reduced the film deposition rate sharply. The silicon nanograins in the SiNx matrix were in a crystalline state, and the density of defects at the silicon nanocrystals (nc-Si)/SiNx interface decreased significantly and the optical gap of the films widened. These results suggested that hydrogen activated by the plasma could not only eliminate in the defects between the interface of silicon nanograins and SiNx matrix, but also helped the nanograins transform from the amorphous into crystalline state. By changing the hydrogen dilution ratio in the reactant gas sources, a tunable band gap from 1.87 eV to 3.32 eV was obtained in the Si/SiNx film.

In situ energy dispersive x-ray diffraction for natural marmatite (Zn0.76Fe0.23S) is performed up to 17.7 GPa and 623 K. It is fitted by the Birch–Murnaghan equation of state (EOS) that K0 and α0 for marmatite are 85(3)GPa and 0.79(16)×10−4 K−1, respectively. Fe2+ isomorphic replacing to Zn2+ in natural crystal is responsible for high bulk modulus and thermal expansivity of marmatite. Temperature derivative of bulk modulus (∂K/∂T)P for marmatite is fitted to be -0.044(23) GPaK−1. The unambiguous B3–B1 phase boundaries for marmatite are determined to be Pupper(GPa) = 15.50−0.016T(°C) and Plower(GPa)=9.94–0.012T(°C) at 300–623 K.

EAST (HT-7U) is a large fusion experimental device. It is a full superconducting tokamak with 1 MA of plasma current, 1000 s of plasma duration, high elongation and triangularity. It mainly consists of superconducting magnets of poloidal and toroidal field (PF & TF), vacuum vessel (VV), thermal radiation shield (TRS) and cryostat vessel (CV). The significant difficulty for assembly of EAST is tight installation tolerances, which are in the order of several tenth of a millimeter. In particular, the alignment of plasma facing components to the magnetic axis of the device is less than ± 0.5 mm. At present, a reasonable assembly process of EAST has been defined, and based on it, the alignment method for EAST, including the survey control network, the location of the main components in different directions, the magnetic axis determination and the accurate positioning of the plasma facing components inside of the vacuum vessel and so on, has been defined by using the sophisticated optical metrology system (SOMS). This paper describes the assembly procedure of EAST and the installation tolerances associated with the main components. Meanwhile, how to establish the assembly survey control network, magnetic axis determination methods, are introduced in detail.

Classically energetically inaccessible parts of energy eigenfunctions in configuration space are studied by making use of a generalization of Brillouin–Wigner perturbation theory. Approximate formulas are proposed for describing local decaying rate of this part of energy eigenfunctions, which are useful in the study of quantum phenomena, such as tunnelling effect, and are tested in an anharmonic oscillator.

Based on our previous study [Chin. Phys. Lett. 20 (2003) 1144] on the solid state cathodoluminescence from organic luminescent materials, here we study the origin and characteristics of blue light emission in solid state cathodoluminescence of Poly [(2-methoxy-5-(2'-ethyl-hexyloxy)phenylene vinyene] (MEH-PPV) and the dependence of each spectral peak on electric field strength. The results demonstrate that the blue spectral shift benefits from field ionization of excitons, and three regions of electric field are found, in which there are pure exciton emission, coexistence of exciton emission and radiative recombination, and pure radiative recombination.

Impedance spectra of gabbro were measured at 1–2 GPa and up to 890°C with applied frequency of 12 to 105 Hz. At temperatures below 680°C, only one impedance arc corresponding to the grain interior conduction process occurs. Owing to the grain boundary transport with increasing temperature, the impurities occur at the grain boundaries, resulting in the second arc corresponding to the grain boundary conduction process over the frequency range of 12 to 10 3Hz above 680°C, and the resistivities of the grain interior and the grain boundary conduction mechanisms add in series. The total conductivity of this rock is dominated by the grain interior conductivity and the impurities have no significant effect on the total electrical conductivities.

The HT-7U tokamak is a magnetically-confined full superconducting fusion device, consisting of superconducting toroidal field (TF) coils and superconducting poloidal field (PF) coils. These coils are wound with cable-in-conductor (CICC) which is based on UNK NbTi wires made in Russian [1]. A single D-shaped toroidal field magnet coil will be tested for large and expensive magnets systems before assembling them in the toroidal configuration. This paper describes the layout of the instrumentation for a superconducting test facility based on the results of a finite element modeling of the single coil of toroidal magnetic field (TF) coils in HT-7U tokamak device. At the same time, the design of coil support structure in the test facility is particularly discussed in some detail.

The Helimak of USA is a plasma physics experimental device designed and built by CASIPP. Its configuration of magnetic field is of very importance during the operation of this device. In this paper, the influence of magnetic permeability on configuration of magnetic field will be discussed due to the effect of weld metal in the vacuum vessel of Helimak, and some conclusion is useful for some engineering designs of the fusion experimental device.

Corundum megacrysts in alkali basalts are an important source of gems. However, the genesis of corundum megacrysts is still a controversial problem. Up to now, no experimental evidence has been acquired for the crystallization of corundum from basalt under high temperature and high pressure. With alkali basalt as the starting material in this experiment, the transformation of basalt into eclogite at the pressure of 3.5 GPa and the temperature of 1400°C was realized. In the experimental product, corundum has been discovered embraced in garnet.

Garnet growth in the early stage of the trachybasalt-eclogite transformation was observed at 2.0 GPa and temperatures of 860°C, 940°C and 1020°C for annealing times of 0.66-13.6 h. The grain size was determined optically to be increased with increasing annealing time. The growth rate decreased with increasing grain size. The garnet growth law was G2.46 = 5.65×10-15texp [-27.40×103/RT], where G represents the average grain size after annealing time t, R is the gas constant and T is the absolute temperature.

For energy eigenfunctions in 1D tight binding model, the distribution of ratios of the nearest components (Riccati variable), denoted by f(p), gives information on their fluctuation properties. The shape of f(p) is studied numerically for three versions of the 1D tight binding model. It is shown that when perturbation is strong the shape of f(p) is usually quite close to that of the Lorentzian distribution and in the case of weak perturbation the shape of the central part of f(p) is model-dependent while the shape of tails are still close to the Lorentzian form.

The Toroidal Field (TF) coil case of the HT-7U superconducting tokamak device is made of austenitic stainless steel 316LN and is designed to operate at cryogenic temperature (4 K). 316LN can retain high strength and fracture toughness at 4 K. Feasibility study on technical process of welding has been experimentally considered as a hopeful joint method for suppression of post-welding deformation and reduction of over-heating. Meanwhile the final range of stress intensity and the stress intensity factor (K) for pre-cracks of welding structure have been determined by using J-integral. These related results are optimistic and have shown that there's no problem in strength and fracture toughness at the vicinity of the pre-crack tip. This paper introduces the welding structure of TF coil case in detail.

The Wigner band random matrix model is studied by making use of a generalization of Brillouin–Wigner perturbation theory. Energy eigenfunctions are shown to be divided into perturbative and nonperturbative parts. A relation between the average shape of eigenstates and that of the so-called local spectral density of states (LDOS) is derived by making use of some properties of energy eigenfunctions drawn from numerical results. Several perturbation strengths predicted by the perturbation theory are found to play important roles in the variation of the shape of the LDOS with perturbation strength.

A simple technique for sensitive detection of heroin based on surface-plasmon-resonance has been theoretically and experimentally investigated. The experiment was realized by using an anti-MO monoclonal antibody and a morphine (MO)-bovine serum albumin (MO-BSA) conjugate (antigen). The reason for using MO-BSA in the detection of heroine was also discussed. MO-BSA was immobilized on a gold thin film of SPR sensor chip by physical adsorption. The configuration of the device is allowed to be further miniaturized, which is required for the construction of a portable SPR device in the application of in-situ analysis.

The toroidal magnet system of HT-7U is a very important part of the HT-7U superconducting tokamak device, which is consisted of sixteen D-shaped coils. In order to design the mechanical structure of the toroidal field (TF) system it is necessary to analyze the mechanical behaviors of the HT-7U TF coil system under normal and all possible fault operating conditions. The force distribution of the TF system in the equilibrium condition (all the coils energized) has been calculated [1]. In this paper, the fault conditions (one or more toroidal coils failed) have been analyzed based on the hypothesis that the current of all the other coils is kept constant when one or more coils failed. The aim is to provide necessary data for the stress analysis of TF structure.

Microstructure modification of silicon nanograins embedded in silicon nitride films by introducing hydrogen reactant in the plasma enhanced chemical vapour deposition process and their optical properties are analysed using Raman scattering, optical absorption and photoluminescence (PL) measurements. It is found that the silicon nanograins embedded in the silicon nitride (SiNx) matrix are transformed into silicon nanocrystals and the optical properties of the films change dramatically when introducing H2 into Ar-sustained plasma. The optical absorption coefficient of the films within the band gap decreases by about one order of magnitude and the PL intensity increases significantly, compared with that without hydrogen introduction. These results suggest that atomic hydrogen in the plasma has the function of crystallizing silicon nanograins and passivating defects at the silicon nanograins/SiNx interface.

An approximate formula is proposed for the decay rate of energy eigenfunctions in classically energetically inaccessible regions in more than one-dimensional configuration spaces. This is achieved by generalizing an approach proposed recently for energy eigenfunctions in the one-dimensional configuration space. The formula is tested numerically in the Pullen–Edmonds model.

The general expressions of the elastic fields induced by straight dislocations in quasicrystals have been given according to Eshelby's method which was used to treat the anisotropic elasticity of dislocations in crystals. As an example, the elastic displacement vector, the stress tensor and the elastic energy density of a screw dislocation line lying on the quasiperiodic plane of decagonal quasicrystals are calculated.

Ultrasonic P wave velocity (VP) and quality factor (QP value, on behalf of attenuation) in pyroxenite were presented as functions of pressures (0.3-3.0 GPa) and temperatures (20-1170°C). The experimental results show that VP and QP depend upon pressure and temperature. VP and QP in pyroxenite increase more rapidly at the pressure 0.3-1.4 GPa than those at 1.4-3.0 GPa. As the temperature rising from 20°C to about 1170°C at the pressure 3.0 GPa, an almost linear decrease up to 11% in VP was observed, and QP drops from 243 at room temperature to 68 at 1170°C with decreasing 72%. The experimental data indicate that the pressure and temperature induced fabric changes and frictional sliding and dislocation in pyroxenite play a key role in wave propagation in rocks.

The application of group theory to elasticity in two-dimensional (2D) quasicrystals is presented. The expression of elastic energy as a function of gradients of the phonon and phason fields has been derived to quadratic order. The phonon response to an external stress is isotropic, but the response of phason field is anisotropic for eightfold and twelvefold symmetries.

For a schematic shell model, we show numerically that, contrary to the behaviour of eigenfunctions, the shapes of the so-called local spectral density of states become close to their forms at extremely strong perturbation (after rescaling) even when the perturbation is relatively weak. The same phenomenon is also found for the random version of the schematic shell model. We suggest that this property of the local spectral density of states may be common to models in which the Hamiltonian matrices in independent particle states have a banded and regular structure.

Calculations are presented in this paper for the flow fields, growth rate and solute transport during crystal growth from solution at various gravity levels.

A transmission-reflection-combined new method is presented for measuring elastic velocities of rocks and minerals at elevated temperature and pressure, which resolves the problems of gradients of temperature and pressure existing in original sample assembly with a pyrophyllite cube. At room temperature and pressure up to 3 GPa, single-crystal quartz and eclogite were used to provide samples under test, respectively. The results of this work agree with the previous measurements very well within the error range. By the use of this new technique, more precise and reasonable data of elastic properties of rocks and minerals at elevated temperature and pressure can be achieved.

A non-linear vibration of the stretch of hydrogen bonds has been studied theoretically. The authors have used the potential V(r)=Ar2-Br3, where A and B are constants, to describe approximately the H-bond energy. They have obtained analytical solutions of the motion equation for a particle moving in this potential field. The theoretical results have been applied to some realistic physics systems, including water molecules, the DNA double helix and the alpha -helix protein. It is shown that the calculated vibration frequencies are in agreement with experimental data observed by the Raman scattering and other techniques. The asymmetry of the H-bond energy is also discussed.