Carbon nanotubes (CNTs) are prepared by means of plasma arc method in this paper. During this experimentation,anode and cathode which are made of graphite material are introduced,Fe/Co/Ni catalyst,S grow substance,H_2/Ar and H_2/He buffer gas.

The conclusion that the environmental temperature of reactor is below 373K is obtained by calculation on the base of pressure module, whereas the temperature of plasma arc axis is about from 5000K to 6500K by calculating current density and conductive rate.

The preparation for CNTs of high quality is the basis of their theoretical and application study. Consequently SWNTs are prepared through plasma arc discharge method, and in this method graphite powder is used as raw material, Fe/Co/Ni as catalyst, FeS as growth substance, H_2/Ar as buffer gas.

The uniformity of large area diamond filrns in deposition process and quality of diamond films is researched. The results show tha the DC arc used for deposition of diamond films is uniform.

1Cr17 stainless steel nanoparticles and its carbon-coated nanoparticles were produced by hydrogen arc plasma method in ( H2 + Ar) and CH4, respectively. The nanoparticles were characterized by X-ray diffraction (XRD) , transmission electron microscopy (TEM) , thermal analysis system (DSC) , etc.

In order to figure out the characteristics of plasma arc beam and mould in the PLDM process of high temperature alloy, the high speed CCD camera is used to obtain the picture around the plasma arc.

And the effect of laser parameter, such as average power, pulse width, pulse repetition frequency and the angle between laser beam and plasma arc beam on the plasma arc appearance, is studied experimentally.

The results show that the modality of plasma arc beam is markedly influenced by laser beam.

On the heat conduction problem and a design principle for plasma arc furnace

In this paper a plane heat conduction problem with variable coefficients of heat conductivity K(T) is analysed with given electric power supplied to the plasma arc.

This paper describes a method of determination of the temperature distribution of an arc plasma. This method is able to evaluate the axisymme-tric emission coefficient and temperature field from radiation intensity measuremen-ts which can be realized by use of photographic detection. This method is called"off-axis peak intensity of emitting spectral line" or lorentz method. The Argonplasma used in our experiments at 170 ampere, 60 volt can be reasonablely assu-med as in local thermodynamic equilibrium, optically...

This paper describes a method of determination of the temperature distribution of an arc plasma. This method is able to evaluate the axisymme-tric emission coefficient and temperature field from radiation intensity measuremen-ts which can be realized by use of photographic detection. This method is called"off-axis peak intensity of emitting spectral line" or lorentz method. The Argonplasma used in our experiments at 170 ampere, 60 volt can be reasonablely assu-med as in local thermodynamic equilibrium, optically thin and axisymmetric. Underthese conditions the measured radiation intensity is consequently the integrated con-tribution of all the emission along the path as the emitted energy travels throughthe arc without attenuation. The emission coefficient is expanded in terms of a fi-nite number of Fouries Series. Integral equation relating the emission coefficientto the emitted spectral intensity is used to determine the unknown expansion co-efficients. As a result the radial temperature distributn of the arc plasma has beendetermined by a comparison between relative peak emission coefficient S (r)/S(r~*) and S (T)/S (T~*). The advantage of this method lies in the fact that onlyone spectral line intensity has to be measured in instead of two spectra line intn-sity in relative spectral line intensity method. In our practice ArI 4510 and ArI6965 are chosen for intensity measurements and the results of these two measure-ments are in quite good agreement with each other. Since in our measurements it isunnecessary to use the spontaneous transition probabilites, which is usually measur-ed in great error, the accuracy of this method is better than that of the relativespectral line intensity method. However, the temperature measured by this methodhas a lower temperature limit, for argon arc plasma the core temperature must behigher than the normal temperature of argon atomic spectral line (about 15×10~2K). In principle the upper temperatiure limit of this method is up to the completeionzation temperature.

In this paper a plane heat conduction problem with variable coefficient of heat conductivity K(T) is analysed with given electric power supplied to the plasma arc. The governing equation for unknown temperature distribution is a nonlinear one with a δ function as its nonhomogenious term. To make the problem attractable by the method of separation of variables, a set of transformation of governing equation is introduced. An explicit simple formula is found for the efficiency of the furnace η. η depends linearly...

In this paper a plane heat conduction problem with variable coefficient of heat conductivity K(T) is analysed with given electric power supplied to the plasma arc. The governing equation for unknown temperature distribution is a nonlinear one with a δ function as its nonhomogenious term. To make the problem attractable by the method of separation of variables, a set of transformation of governing equation is introduced. An explicit simple formula is found for the efficiency of the furnace η. η depends linearly on r0, the nondimensional distance between the arc and surface of melted material, as well as on another nondimensional quantity Q, we described the above in detail in the paper. This relationship holds for r0<0.4, and gives a good guidance for the design of furnace.

Based on approximate similarity theory, arc plasma equa- tions are analyzed. Dimensionless generalized voltage-current characteris- tic which represents correlation of vortex-stabilized plasma arcs is ob- tained, and is verified with experiment data of arc air heater in the mag- nitude of 100 kW. When radiation is neglected, and dimensionless ge- neralized characteristic proposed in this article is compared with the results of , Shashkov and Yasko et al., good agreement is found. The functional expressions are...

Based on approximate similarity theory, arc plasma equa- tions are analyzed. Dimensionless generalized voltage-current characteris- tic which represents correlation of vortex-stabilized plasma arcs is ob- tained, and is verified with experiment data of arc air heater in the mag- nitude of 100 kW. When radiation is neglected, and dimensionless ge- neralized characteristic proposed in this article is compared with the results of , Shashkov and Yasko et al., good agreement is found. The functional expressions are basically reasonable.