Direct measurement of the surface dynamics of supercooled liquid-glycerol by optical scanning a film

The surface dynamics of supercooled liquid-glycerol is studied by scanning the thickness of the glycerol film with single photon detection. Measurements are performed at room temperature well above the glycerol's glass transition temperature. It is shown that the surface dynamics of the glycerol film is very sensitive to the temperature. The linear relationship between the thickness of the film and the viscosity predicted by the Vogel--Fulcher--Tammann--Hesse (VFTH) law is also presented experimentally.     

An efficient deterministic secure quantum communication scheme based on cluster states and identity authentication

A novel efficient deterministic secure quantum communication scheme based on four-qubit cluster states and single-photon identity authentication is proposed. In this scheme, the two authenticated users can transmit two bits of classical information per cluster state, and its efficiency of the quantum communication is 1/3, which is approximately 1.67 times that of the previous protocol presented by Wang et al [Chin. Phys. Lett. 23 (2006) 2658]. Security analysis shows the present scheme is secure against intercept-resend attack and the impersonator's attack. Furthermore, it is more economic with present-day techniques and easily processed by a one-way quantum computer.     

Vacuum Outer-Gap Structure in Pulsar Outer Magnetospheres

We study the vacuum outer-gap structure in the outer magnetosphere of rotation-powered pulsars by considering the limit of trans-field height through a pair production process. In this case, the trans-field height is limited by the photon-photon pair production process and the outer boundary of the outer gap can be extended outside the light cylinder. By solving self-consistently the Poisson equation for electrical potential and the Boltzmann equations of electrons/positrons and γ-rays in a vacuum outer gap for the parameters of Vela pulsar, we obtain an approximate geometry of the outer gap, i.e. the trans-field height is limited by the pair-production process and increases with the radial distance to the star and the width of the outer gap starts at the inner boundary （near the null charge surface） and ends at the outer boundary which locates inside or outside the light cylinder depending on the inclination angle.     

La-Ce-TiO2纳米光催化剂的溶胶-微波法合成、谱学表征及其活性研究

以钛酸四丁酯为原料,采用溶胶-微波法(Sol-Microwave Method)合成了镧和铈共掺型纳米TiO2粉体(La-Ce-TiO2),借助XRD、XPS和UV-Vis等测试手段对其进行了表征,并以甲基橙为模型污染物考察了掺杂量对样品光催化活性的影响规律.XRD分析表明,所得粉体均为锐钛矿相纳米TiO2,且稀土元素镧和铈掺杂后纳米TiO2特征衍射峰宽化,强度降低;XPS分析表明,镧和铈掺杂后样品表面存在大量的氧缺位;UV-Vis吸收光谱表明,所得粉体在400 nm以下均有连续宽化的吸收带,且La和Ce掺杂后样品对光的吸收显著增强,这足由于La(Ⅲ)-O荷移跃迁以及Ce(Ⅳ)f→d跃迁和Ce(Ⅳ)-O荷移跃迁所致;光催化实验表明,La和Ce共掺杂能显著提高纳米TiO2的光催化活性,其中当La(Ⅲ)和Ce(Ⅳ)掺杂量分别为2%和0.04%时,纳米TiO2光催化剂具有较高的催化活性,自然光照射下光催化氧化处理卷烟厂蒸叶车间废水,效果较好,废水COD去除率达到86.11%.     

532-nm picosecond pulse generated in a passively mode-locked Nd:YVO_4 laser

A diode-pumped continuous-wave （CW） mode-locked Nd：YVO4/KTP green laser with semiconductor saturable absorber mirror （SESAM） is demonstrated. The maximum output power of CW mode-locked green laser is obtained to be 552 mW at the incident pump power of 7.25 W, corresponding to an opticai-optical conversion efficiency of about 7.6%. The 532-nm CW mode-locked pulse duration is estimated to be about 8.4 ps with the repetition rate of 87 MHz.     

High-spin states in neutron-rich 102Mo nucleus

High-spin states in neutron-rich 102Mo nucleus have been studied by measuring the prompt γ-rays in the spontaneous fission of 252Cf. The previous level scheme has been updated and some new levels and transitions are identified. The one-phonon γ-band is expanded and a band head level of the two-phonon γ-band is proposed. The systematic characteristics of yrast bands, one-phonon γ-bands, two-phonon γ-bands and quasi-particle bands in 102Mo, 104Mo and 106Mo are discussed.     

Bulk-sensitive spectroscopic studies on noncentrosymmetric superconducting system of Mg–Ir–B

We present the data from ultrahigh-resolution laser-excited photoemission spectroscopy on a newly discovered noncentrosymmetric superconductor Mg₁₀Ir₁₉B₁₆. We observed the evidences for the opening of superconducting gap where numerical fittings show that isotropic s-wave model can satisfactorily explain the behavior of spectra near the Fermi level. We also present the valence band photoemission spectrum and B K fluorescence spectrum to discuss the basic electronic structure of Mg₁₀Ir₁₉B₁₆.     

6.17-W continuous wave operation of a 2132-nm c-cut Tm,Ho:YAP pumped by a laser diode of 794.3 nm

Continuous wave (CW) operation of a c-cut Tm (5 at %), Ho (0.3 at %):YAP laser at 2132 nm wavelength were reported in this paper. In the temperature of 77 K, the Tm,Ho:YAP crystal was double end-pumped by a 21.4 W fiber-coupled laser diode (LD) at the center wavelength of 794.3 nm. Different resonator lengths and output couplers for the total pump power were tried. The resonator length was 205 mm, and the maximum CW output power of 6.17 W was acquired, corresponding to an optical-optical conversion efficiency of 28.8% and a slope efficiency of 35.6%.     

Facile method for CLSM imaging unfunctionalized Au nanoparticles through fluorescent channels

The microscopic visualization of metal nanoparticles has become a useful tool for the investigation of their applications in cell labeling and the study of their bio-effects. In the current study, we have developed a facile method with confocal laser scanning microscope (CLSM) to observe unfunctionalized Au nanoparticles through fluorescent channels. The sharp reflected signal and photostable property of the metal nanoparticles makes the present method very ideal for fluorescent co-localization, real-time imaging, and further quantitative analysis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Lan Yuan and Wei Wei contributed equally to this study.     

土壤源热泵在合肥某工程中的应用

介绍了土壤源热泵的工作原理,探讨了土壤源热泵空调应用于中央空调系统的设计方法,以及其主要部件地热换热器的埋管方式、结构、管材、运行等特点。选取几种常用的冷热源系统与土壤源热泵系统进行比较分析,参考合肥地区的能源价格,计算各方案的运行成本,用动态费用年值法对各方案的经济性进行了评价。