[en] There is a growing need for high power YAG laser beam diagnostics with the recent introduction of such lasers in laser material processing. In this paper, we will describe the use of a commercially available laser beam analyzer (Prometec) to profile the laser beam from a 1600 W pulsed Nd:YAG laser that has a 1 mm fiber optic beam delivery system. The selection of laser pulse frequency and pulse width for the measurement is discussed. Laser beam propagation parameters by various optical components such as fibers and lenses can be determined from measurements using this device. The importance of such measurements will be discussed

[en] The standard molar reaction enthalpies of two reactions, CeCl₃·7H₂O(s) + 3CCl₃COOH(s)(or TCA) = Ce(TCA)₃·3H₂O(s) + 3HCl(g) + 4H₂O(l) and Ce(TCA)₃·3H₂O(s) + 2C₉H₇NO(s) Ce(TCA)(C₉H₆NO)₂(s) + 2CCl₃COOH(s) + 3H₂O(l), were studied by classical solution calorimetry at 298.15 K. The molar dissolution enthalpies of the reactants and the products in certain solvent (the first reaction in 1 mol/l HCl, the second in a mixed solution consisting of absolute ethyl alcohol, dimethyl sulfoxide and 4 mol/l HCl) have been measured by using an isoperibolic calorimeter at 298.15 K. From the results and other auxiliary quantities, the standard molar formation enthalpies of [Ce(TCA)₃·3H₂O, s, 298.15 K] and [Ce(TCA)(C₉H₆NO)₂, s, 298.15 K] were determined to be Δ_fH_m^θ [Ce(TCA)₃·3H₂O, s, 298.15 K] = -3059.9 kJ/mol and Δ_fH_m^θ [Ce(TCA)(C₉H₆NO)₂, s, 298.15 K] = -1368.9 kJ/mol

[en] Optical coherence tomography (OCT), based on a Michelson interferometer and utilizing low coherence light as the optical source, is a novel technique for the noninvasive imaging of optical scattering media. A simple OCT scheme based on a 3x3 fiber coupler is presented for the simultaneous measurement of the refractive index and thickness of optical samples. The proposed system enables the refractive index and thickness to be determined without any prior knowledge of the sample parameters and is characterized by a simple and compact configuration, a straightforward measurement procedure, and a low cost. The feasibility of the proposed approach is demonstrated experimentally using BK7 and B270 optical glass samples.

[en] This paper is to present the mythology and results of electromagnetic radiation monitoring at a mobile communications indoor base in Shanghai from 2004 to 2008. Both theoretical calculation and measurement of electromagnetic radiation at 1 m at axis of the base antenna are in a good agreement, below national standards of 12 V/m, e.g. 5.37 V/m. (author)

[en] Ionization chamber is often used to detect the background gamma radiation due to its good energy response. The energy response of ionization chamber is determined by the parameters of geometry, materials and gas pressure. In this paper, the Monte Carlo method is used to perform the energy response of ionization chamber with the type of AGM-5. The results of Monte Carlo simulation show good agreement with the data obtained by experimental method. (author)

[en] Using an on-line solution-reaction isoperibol calorimeter, the standard molar enthalpies of reaction for the general thermochemical reaction: LnCl₃·6H₂O(s) + 2C₉H₇NO(s) + CH₃COONa(s) Ln(C₉H₆NO)₂(C₂H₃O₂)(s) + NaCl(s) + 2HCl(g) + 6H₂O(l) (Ln: Nd, Sm), were determined at T=298.15 K, as -(56.9±1.4) and-(67.9±1.5) kJ mol^-l, respectively. From the mentioned standard molar enthalpies of reaction and other auxiliary thermodynamic quantities, the standard molar enthalpies of formation of Ln(C₉H₆NO)₂(C₂H₃O₂)(s) (Ln: Nd, Sm), at T=298.15 K, have been derived to be: -(1494.7±3.3) and -(1501.5±3.4) kJ mol^-l, respectively

[en] The mixed complex of Nd³⁺ with glycine and alanine, Nd(Gly)₂(Ala)₃Cl₃·2H₂O, was synthesized and characterized by IR, elementary analysis, thermogravimatric analysis and chemical analysis, and the dissolution enthalpies of NdCl₃·6H₂O(s), 2Gly(s) + 3Ala(s) and Nd(Gly)₂(Ala)₃Cl₃·2H₂O(s) were determined in 2 mol/L HCl by the classical solution calorimetry. By designing a thermochemical cycle according to Hess' law and through calculation, we obtained the reaction enthalpy of neodymium chloride six-hydrate with glycine and alanine: Δ_rH deg._m(298.15 K)=37.24±0.299 kJ/mol, and the standard enthalpy of formation of Nd(Gly)₂(Ala)₃Cl₃·2H₂O(s): Δ_fH deg._m[Nd(Gly)₂(Ala)₃Cl₃·2H₂O, s, 298.15 K] -4441.6±8.262 kJ/mol

[en] Titania-hydroxyapatite (HA) nanocomposites were fabricated by wet chemical synthesis approach. HA exhibited crystallographic orientation of nucleation on nano titania particle, forming the composite particles with titania being partially enwrapped with HA. Microstructural characterization by high resolution transmission electron microscopy revealed coherent interfacial bond of (110) and (222) planes of HA crystal with (101) plane of anatase. The HA layer promoted significantly recruitment of Escherichia coli bacteria onto the titania-based particles for subsequent photocatalytic killing. Less extent of enwrapping of HA on titania particle, as accomplished by increasing the aging time of HA suspension, gave rise to better capability of photocatalytic degradation of methylene blue and sterilization of the bacteria. The novel HA-enwrapped titania powder shows great potential for environmental applications. - Highlights: • Titania-hydroxyapatite nanocomposite powder was fabricated with cladding structure. • Hydroxyapatite nucleated and grew on titania particle with preferred orientation. • Hydroxyapatite layer promotes recruitment of Escherichia coli onto titania-based particles. • The titania-hydroxyapatite particles show excellent antibacterial performances. • The nanocomposite powder exhibits excellent photocatalytic performances

[en] The outer divertor plasma of HL-2A and its associated scrape-off plasma have been simulated using a two-dimensional multi-species fluid code of Braams with a simplified neutral gas model. HL-2A has a double-null closed divertor in separate divertor chambers above and below the nearly circular plasma tours. The computed numerical grid is developed according to an ideal magnetic surface. The calculation is involved only with pure hydrogen plasma. The emphasis has been focused on parametric studies involving variation of the assumptions made for the core plasma. The peak temperatures and the heat flux near the target are of the principal concern

[en] Full text: On the HL-2A tokamaks, series of experiments have been conducted to shed light on the persistent m/n=1/1 mode topology and its influence on transport properties in the plasma centre. Several new characteristics of central MHD activities during auxiliary fuelling and heating are discussed, and some important information about the changes in local plasma parameters and how the plasma responds to the perturbation caused by molecular beam injection (MBI) or laser blow-off are provided. Several important central MHD activities, for example, sawtooth suppression, monster and compound sawtooth, and persistent m/n=1/1 oscillations, have been observed. A large, long persistent m/n=1/1 perturbation has newly been observed in the core region after molecular beam injection, a detailed study on the influence of MBI on central pressure gradient and the stability of central plasma has been made. Especially, possible mechanisms for the formation of the continuous mode or snake-like perturbation during MBI are discussed. In laser blow-off experiments, persistence of the m=1 oscillation after the internal disruption of inverted sawtooth is found. With the illumination effect of the impurity radiation, the island structure after sawtooth crash can be studied. Such a delicate study provides much information about the evolution of the central q profile and the reconnection process. During electron cyclotron heating (ECRH), a strong m=1/n=1 mode is excited when the heating power is high enough and the resonance position is located just around the core of plasma. With the strong m=1 oscillation driven by ECRH, a sawtooth tends to saturate or decrease in its ramp phase and the shape of sawtooth is usually changed, leading to formation of a saturated sawtooth, a hill, or a compound sawtooth. Experimental results indicate that there is evidence for an internal steep electron temperature profile associated with the q=1 rational surface before the compound crash. The effect of ECRH on plasma transport properties in the vicinity of the q=1 surface are investigated. (author)