Finally, it turned to be controlled by dissolution of Ca(OH)_2. TEM and X-ray diffraction were used to observe the nucleation and growth of CaCO_3 ultrafine particles. The effects of additives were discussed.

The conversion of magnetite to maghemite has been studied by Mb'ssbauer effect. That is a nucleation and growth process of γ-Fe2O3. The change of the concentration of Fe3O4 with time was determined by the change of magnetic moment in the oxidizing process.

The possible reaction mechanism and the kinetic equation were suggested by comparing the kinetic parameters. The result shows that this dehydrate process is nucleation and growth. The kinetic equation can be expressed as:dα/dt=Aexp(-E/RT) {(1-α)[-ln(1-α)]~(-1)/2}

It is found by the research that Fe_3O_4 and FeO were formed by oxidation and reduction between iron oxide coating on iron catalyst surface and carbon source of graphite at 5.7GPa and 1600℃,with some iron melted and exuded out,its contact with carbon source of graphite caused diamond nucleation and growth.

The results showed that the Fe_(2)O_(3) layer was deoxidized by graphite to form Fe_(3)O_(4) and FeO at 5.7 GPa and 1600℃. At the same time the iron melted and exuded through the Fe_(2)O_(3) layer,and then contacted with graphite,to realize the nucleation and growth of diamond.

And then, under different probabilities of growth and neighbor conditions, the modified model of random successive nucleation growth (RSNG) is adopted to simulate the one-dimensional growth of fractal aggregation, the aggregation generation by generation (AGG) model is used for two-dimensional growth, and the property of the critical percolation is studied emphatically.

然后，在不同的生长概率和不同的近邻条件下，采用改进的随机逐次成核生长(RSNG—Random Successive Nucleation Growth)模型，模拟一维分形凝聚生长； 采用代代凝聚(AGG—Aggregation Generation by Generation)模型，模拟二维分形凝聚生长；

We present a randomsuccessive nucleation growth model,a two-and a three-dimensional aggregation generation-by-generation model to investigate percolation properties of fractal aggregations with various neighbor conditions and lattice size.

It was found that a chain monolayer of polyaniline crystal cell was formed by the two dimensional instantaneous nucleation growth without diffusion control during the initial stage of eletropolymerization, and after forming the monolayer, the growing process of polyaniline tubules was controlled by diffusion instead.

the dehydrate process between 703 K and 843 K is controlled by nucleating and growing with an activated energy of 198.89 kJ/mol,a pre-exponential factor of 2.458 5×10~(13) s~(-1).

The decomposition reaction from 1070K to 1210K is LiMn2O4 (Cubic)→LiMn2O4-δ(Orthorhombic) +δ/2O2(g)(?) , which is controlled by nucleating and growing, and the activated energy is 204.16kJ/mol.

The reaction from 1210K to 1473K is 3LiMn2O4_δ(Orthorhombic)→LiMnO2+ Mn3O4 + Li2Mn2O4+(l-3δ/2)O2 (g)(?) . Nucleating and growing is the key step of the process from 1210K to 1300K, and its activated energy is 185.61kJ/mol.

The mechanism of mutual influence of microcrystal nucleation and growth processes is proposed.

The kinetics of particle nucleation and growth is studied within the framework of the model of diffusion-limited aggregation by the combined marching and Monte Carlo methods.

The kinetics of particle nucleation and growth is studied within the framework of the model of diffusion-limited aggregation by the combined marching and Monte Carlo methods.

Detailed control of the conditions favorable for the nucleation and growth processes of nanorods of a given SiC polytype is necessary because the electrical and optical properties of each SiC polytype are very different.

The nucleation and growth of crystals in a gel of alkali lead borosilicate composition are investigated.

The suggested method for revealing the Si nanocrystals and clusters incorporated into the oxide provides a convenient way to study the specific features of nucleation growth and spinodal decomposition in the Si solid solution in the SiO2 oxide.

It is indicated that the particle growth is promoted mainly by coagulation process but not nucleation growth.

For μ >amp;gt; μc the chargeless ring triggers the nucleation growth into the planar polar structure with line defects.

The available isothermal nucleation growth-rate equation has been modified for non-isothermal kinetic analysis.

Polynucleation model in two-dimensional nucleation growth theory is suggested as the most possible growth mechanism for these crystals in the present supersaturation range.

Experiments were made on the growth of copper and iron whiskers by means of vapour reduction. The mechanism of growth was studied in order to find out the effective procedures of growing thick and long whiskers with very high strength. The growth of whiskers was found to be facilitated when the crystal structure of the grow-boat material is similar to that of the whisker. This led to the conclusion that the growth of whiskers is through a mechanism involving an axial screw dislocation. On the basis of observations...

Experiments were made on the growth of copper and iron whiskers by means of vapour reduction. The mechanism of growth was studied in order to find out the effective procedures of growing thick and long whiskers with very high strength. The growth of whiskers was found to be facilitated when the crystal structure of the grow-boat material is similar to that of the whisker. This led to the conclusion that the growth of whiskers is through a mechanism involving an axial screw dislocation. On the basis of observations on the mode of distribution and the direction of growth of the copper and iron whiskers grown on the wall of the boat, it was concluded that the growth of these whiskers proceeded from the tip. Furthermore, experiments showed that the cuprous (or ferrous) chloride vapour was preferentially reduced by hydrogen at the tip of the whisker, presumably because of the catalyzing action of the surface step produced at the tip by a screw dislocation.

Computer simulation of the stationary domain in a Gunn diode with a positivedoping gradient near the anode was carried out.Two different kinds of stationary do-main modes were obtained,when the diffusion coefficient of the electrons is assumedto be constant,the high-field domain is initiated at cathode and propagates throughthe active region and finally becomes stationary at the anode.If the diffusion co-efficient is assumed to be dependent on the field of certain definite form,a high-fielddomain may nucleate...

Computer simulation of the stationary domain in a Gunn diode with a positivedoping gradient near the anode was carried out.Two different kinds of stationary do-main modes were obtained,when the diffusion coefficient of the electrons is assumedto be constant,the high-field domain is initiated at cathode and propagates throughthe active region and finally becomes stationary at the anode.If the diffusion co-efficient is assumed to be dependent on the field of certain definite form,a high-fielddomain may nucleate and grow at anode where it becomes stationary.In both casesthe device exhibits a static negative resistance at its terminals,whereas the currentwaveforms are different. The results of the simulation show that the stationary domain generally has thefollowing two features: a) At the edge of the domain near to the anode contact,thediffusion velocity is equal to,or greater than one half of the drift velocity, b) Thedistribution of the electron density is nearly flat in the most part of the domain. The results of the simulation also show that after a stationary domain has beenformed near the anode, further increase of the applied voltage over a certain thresholdvalue will turn the stationary domain into a transit domain again.The critical con-dition of this turnover is analyzed,the results show that the threshold voltage de-pends on the doping concentration in the homegeneous doping region,the doping gra-dient at the anode and the size of the notch near the cathode.

The conversion of magnetite to maghemite has been studied by Mb'ssbauer effect. That is a nucleation and growth process of γ-Fe2O3. The change of the concentration of Fe3O4 with time was determined by the change of magnetic moment in the oxidizing process. The chemical reaction formula, -dC/dt = mC3, is only appropriate for the starting stage of the oxidizing process.