Direct Fabrication of Surface Relief Holographic Diffusers in Azobenzene Polymer Films

We propose a direct fabrication of light diffusers using azobenzene polymer films. Holographic recordings of surface relief diffusers are formed on the polymer film by exposure to an Nd:YAG laser (532 nm) through source diffusion materials. No post-treatment is needed, and it can be erased by heating or irradiating uniform laser beam. Diffusion pattern can be controlled by the polarization of the laser. Transmittance of over 88% is obtained at the wavelength of 633 nm.     

CAES离心压缩机可调扩压器调节规律研究

离心压缩机是压缩空气储能系统中关键设备之一,需具备在较宽流量、压力范围内高负荷高效率运行的能力。作为一种变工况调节技术,可调扩压器可以扩大压缩机工作流量范围,改善气动性能。因此,本文以某压缩空气储能系统用离心压缩机为研究对象,通过数值计算方法研究了可调扩压器调节时压缩机性能变化规律。结果表明采用可调扩压器可以有效拓宽压缩机运行特性,工作流量范围扩大44%,压比范围扩大25%.此后,本文采用Kriging模型获得了压缩机综合性能曲线图和不同储能工况需求下扩压器的调节方案及规律,为压缩空气储能系统离心压缩机变工况主动控制提供了依据。     

Wave Flow and the Resonant Decrease in the Radiation Visibility of Extensive Corrugated Diffusers

In this paper, the problem of electromagnetic wave diffraction by extensive conducting bodies with uniform cross sections and continuous curvature boundaries is studied. Corrugated cylinders are considered as diffusers. A resonant decrease in the radiation visibility of such bodies was discovered.     

高压比离心压气机叶片扩压器设计准则研究

本文对某带叶片扩压器的高压比离心压气机进行数值研究,提出Vt和Vm沿子午流道规律变化的叶片扩压器气动参数设计准则,采用该设计准则的优化结果表明,在保持原型扩压器进出口半径的条件下,压气机压比基本不变,但最高效率提高1.55％,工作裕度扩宽22.22％.同时,本文提供气动参数设计准则相应的快速优化设计流程.该气动设计准则...     

ANTARES, Physics potential, progress and status

Observational neutrino astronomy can bring information - also on particle physics - that can not be obtained in other ways. In general this concerns processes at extreme energy and distance scales. Particularly of interest are cosmic accelerators, GUT phase transition remnants and dark matter annihilation. After four years of R&D the ANTARES Collaboration begins the actual construction of a neutrino telescope to be deployed at 2400 m depth near Toulon in the Mediterranean sea. The telescope will be particularly sensitive to high-energy upward-going neutrinos. The physics case, measurements, the structure of the detector and recent progress are discussed.     

Resonant tunneling,eigenvalue and energy band calculation for potential and periodic potential structures

Recursion formulae for the reflection and the transmission probability amplitudes and the eigenvalue equation for multistep potential structures are derived. Using the recursion relations, a dispersion equation for periodic potential structures is presented. Some numerical results for the transmission probability of a double barrier structure with scattering centers, the lifetime of the quasi-bound state in a single quantum well with an applied field, and the miniband of a periodic potential structure are presented.     

Dynamic holograms recording in fullerene-containing solid-state matrices: Porous glass slides and PMMA films

Fullerene-containing solid-state matrices were studied theoretically and experimentally as the active material for all-optical switching devices. Dynamics hologram recording and spectral analysis were used to study temporal stability and efficiency of nonlinear response of the media. Porous glass and polymethylmethacrylate hosts were utilized as C₆₀-containing matrices. Experiments were carried out using nano- and picosecond laser radiation with wavelength 532 nm.     

石墨烯的结构、性能及潜在应用

石墨烯是一种二维零带隙半金属材料,近年来受到学术界和工业界的广泛关注。文章将石墨烯合成方法分为固、液、气三类并分别加以讨论,介绍了石墨烯的结构和缺陷特征及其电、光、热、力学等性能。石墨烯的应用研究主要集中在电学、力学、选择性分离膜、基底和生长衬底等方面。     

A method for quantitative analysis of clump thickness in cervical cytology slides

Knowledge of the spatial distribution and thickness of cytology specimens is critical to the development of digital slide acquisition techniques that minimise both scan times and image file size. In this paper, we evaluate a novel method to achieve this goal utilising an exhaustive high-resolution scan, an over-complete wavelet transform across multi-focal planes and a clump segmentation of all cellular materials on the slide. The method is demonstrated with a quantitative analysis of ten normal, but difficult to scan Pap stained, Thin-prep, cervical cytology slides. We show that with this method the top and bottom of the specimen can be estimated to an accuracy of 1 μm in 88% and 97% of the fields of view respectively. Overall, cellular material can be over 30 μm thick and the distribution of cells is skewed towards the cover-slip (top of the slide). However, the median clump thickness is 10 μm and only 31% of clumps contain more than three nuclei. Therefore, by finding a focal map of the specimen the number of 1 μm spaced focal planes that are required to be scanned to acquire 95% of the in-focus material can be reduced from 25.4 to 21.4 on average. In addition, we show that by considering the thickness of the specimen, an improved focal map can be produced which further reduces the required number of 1 μm spaced focal planes to 18.6. This has the potential to reduce scan times and raw image data by over 25%.     

Superconductivity,diamagnetism, and the mean inner potential of solids

The mean inner potential of a solid is known to be proportional to its diamagnetic susceptibility. Superconductors exhibit giant diamagnetism. What does this say about the connection between superconductivity and mean inner potential? Nothing, according to the conventional theory of superconductivity. Instead, it is proposed that a deep connection exists between the mean inner potential, diamagnetism, and superconductivity: that they are all intimately linked to the fundamental charge asymmetry of matter. It is discussed how this physics can be probed experimentally and what the implications of different experimental findings would be for the understanding of superconductivity.     

Metallic mean-field stripes,incommensurability, and chemical potential in cuprates

We perform a systematic slave-boson mean-field analysis of the three-band model for cuprates with first-principle parameters. Contrary to widespread belief based on earlier mean-field computations low doping stripes have a linear density close to 1/2 added hole per lattice constant. We find a dimensional crossover from 1D to 2D at doping approximately 0.1 followed by a breaking of particle-hole symmetry around doping 1/8 as doping increases. Our results explain in a simple way the behavior of the chemical potential, the magnetic incommensurability, and transport experiments as a function of doping. Bond centered and site-centered stripes become degenerate for small overdoping.     

Surface charge density,membrane potential and salt flux

The surface charge density of a passive membrane may be determined from the Gouy-Chapman double layer potentials at the membrane surfaces. Here, we show the formal aspect of a method which allows determination of the surface charge density from measurements of the membrane potential, diffusion potential and salt flux through the considered membranes.     

Metastability of defects,potential fluctuations,and percolation transition in GaAs

Potential fluctuations due to donor–acceptor compensation have been used to observe localization–delocalization transition in semi-insulating GaAs. Photoinduced transients, resulting from relaxation of stored charges in potential valleys, have two components. The long-lived power law decay at low temperature signifies a microscopically inhomogeneous disordered phase, and single exponential decay at a higher temperature signifies a homogeneous ordered phase. Temperature dependence of steady state photocurrent and kinetics of photocurrent decay suggest percolation as a possible mechanism for photoinduced transition in semi-insulating GaAs.