分析完全电离等离子体扩散问题的边界单元法

一、扩散方程 完全电离等离子体的扩散问题,可归结为下面的微分方程定解问题。 在内; 在Γ_1上; 在Γ_2上; 式中,A=ηκB~Z/B~Z,n=n(r,t)是等离子体密度,κ是玻尔兹曼常数,T是绝对温度,B是磁感应强度,η是电导率,Ω是由Γ=Γ_1 Γ_2界定的区域,ω是边界的外法向方向,和是边界上的已知函数。     

激光加热微管靶反激光方向二次谐波时空分辨结构

本文报道了高功率激光加热微管靶,从入射激光的反方向观察二次谐波的时空分辨结构,分析了激光与微管靶的相互耦合过程.在激光与等离子体细丝相互作用的理论基础上,解释了微管区域内反激光方向二次谐波辐射的特殊现象.     

Velocity gradient driven flute instabilities in plasmas

The effect of velocity gradient across the magnetic field on the low frequency flute modes is examined in detail, using the normal mode analysis. It is shown that some new type of instabilities driven primarily by the velocitygradient arise and these excited modes eventually attain the convective saturation. The onset of plasma turbulence due to these instabilities may possibly be one of the major contributors for anomalous heating process and enhanced plasma resistivity.     

Properties of high pressure arc plasma

High pressure argon arc discharges are investigated in the pressure range up to 1000 atm. Experimental values of radiative properties such as the frequency-dependent emission coefficient and the total radiation source strength are compared with theoretical predictions. Solutions of the energy balance of wall stabilized high pressure arcs are presented, the agreement with measurements is good. A comparison of measured electrical conductivities of non-ideal argon plasmas with order measurements and with computations following different theoretical approaches, confirms the poor agreement between theory and experiment found by other authors for this regime. Auszug aus einer Habilitationsschrift am Fachbereich für Elektrotechnik der TU München.     

Hydrophilic interaction liquid chromatographic tandem mass spectrometric determination of atenolol in human plasma

A hydrophilic interaction liquid chromatographic method with tandem mass spectrometry for the determination of atenolol, a beta-blocking agent, in human plasma has been developed and validated over the curve range of 10--2000 ng/mL. The assay was based on protein precipitation followed by evaporation of the extraction solvent, reconstitution with acetonitrile, and chromatography on an Hypersil silica column (50 x 4.6 mm) using a low aqueous--high organic mobile phase. The mobile phase consists of 85% acetonitrile, 15% water, 0.5% acetic acid and 0.04% trifluoroacetic acid and runs isocratically at a flow rate of 2.0 mL/min. The column ef fluent was split so that 50% of it was transferred into the LC-MS/MS interface operated in positive electrospray ionization mode. The chromatographic run time was 2.0 min per injection. Atenolol and the internal standard, atenolol-d(7), showed a retention time of 1.0 min. The inter-day and intra-day precision and accuracy of the quality control samples were <5.3% relative standard deviation and <8.0% relative error, respectively. To explore the application of the current method for the analysis of other beta-blocking agents, propranolol and metoprolol were tested under the same chromatographic conditions with retention times of 0.68 and 0.75 min, respectively. The present method could be used for therapeutic drug monitoring, pharmacokinetic and drug--drug interaction studies of beta-blocking agents.     

Ultra-trace analysis of platinum in human tissue samples

Background levels of platinum were determined in human autopsy tissues taken from five individuals. The investigated specimens were lung, liver and kidney. Sample preparation involved microwave digestion followed by an open vessel treatment. Inductively-coupled plasma sector field mass spectrometry (ICP-SFMS) was applied in combination with an ultrasonic nebulization/membrane desolvation system for sample introduction. Isotope dilution analysis was employed for accurate quantification of platinum. Excellent procedural detection limits (3 s validation) of 20, 20 and 34 pg g^–1 dry weight were obtained for lung, liver and kidney tissue, respectively. Due to the lack of appropriate biological reference material, road dust (BCR-723) was used for method validation. Platinum levels ranging between 0.03 and 1.42 ng g^–1 were determined in the investigated samples. The platinum concentrations observed in human lung tissue may reflect the increasing atmospheric background levels of platinum originating from car catalysts. The presence of platinum in kidney and liver tissue samples clearly indicates the bioavailability of the element.     

Plasma chemical vapor deposition of TiN

Experiments indicate that the temperature in chemical vapor deposition (CVD) of TiN can be decreased from about 1000°C in conventional CVD to about 500°C by the application of a D.C. nonequilibrium plasma. The hardness of the TiN film is greater than 2000 kg/mm² (Vickers). The effect of pressure, ratio of gas mixture, and discharge parameters on the film deposition rate, its hardness, and microstructures has been studied.     

Transport in boundary layer of divertor tokamaks

Study of transport in the boundary layer of tokamak plasma in presence of magnetic divertors is extended to the second order in ion collision frequency. Numerical results for ion and energy losses to the collector plates are presented for toroidal and poloidal divertors. For the toroidal case, the Wiener-Hopf solution for the second order distribution function is obtained. An error occurring in an earlier first order calculation is pointed out and corrected first order fluxes are also given. For the poloidal divertor, asymmetry observed in ion and energy transport is found to persist in the second order result.