Search results

Under semisolid region a number of processes can take place simultaneously, resulting on a particular microstructure formed by spheroids of solid surrounded by a liquid matrix.
It is clearly visible a non-dendritic microstructure when solid fraction increases due to dendritic grain growth.

After decades during which the Soviet-owned and later Soviet-German stock company Wismut become the greatest uranium producer of the Eastern bloc and number three world-wide, the new mission assigned to Wismut GmbH was to properly decommission its former uranium mining sites and to rehabilitate the properties for future use.
The mill tailings ponds cover a cumulative surface of more than 570 ha and contain more than 150 million m³ fine-grained uranium mill tailings which were discharged as slurry via pipelines into these basins.

The Absorption edge of as-deposited and post-annealed N/C co-doped TiO2 films prepared under different negative bias Serial number Current(A) Pulse Negative Bias (V) Absorption edge(nm) (As-Dep/annealed1,2,3) 1# 60 0 510/537.5/550 2# 60 -150 500/546/546 3# 60 -300 525 4# 60 -450 520 5# 60 -600 540 3.
The film surface grain size decreased significantly with the bias increasing from 0V to -300V, which is corresponding to the XRD result, the crystal morphology become inconspicuously.

Characterization of electrocrystallization nucleation/growth process is usually performed by analyzing the cyclic voltammograms and the current transients obtained using chronoamperometry technique, and a number of different theoretical formalisms have been developed to identify the different nucleation process and different growth types.
A "current loop" in the -0.93 to -0.8V potential region following scan reversal is observed, and such current loop implies that the electrodeposition of CoNiFe alloy follows three-dimensional (3D) nucleation and grain growth mechanism.

.So that they can show excellentperformance in many different fields[3-6].Many methods have been developed to synthesize CEMNPs[7-10].However,these routes were mainly focused on physical processes,which needhigh energy and intensivehardware.At the present time, sear ching for new strategies for fabrication of CEMNPs has been a hot topic in the field.With this manuscript in mind, a detonation method to prepare for CEMNPs will be reviewed in detail as well.Encapsulation of foreign materials within a graphitic cage was carried out for transition metals(Fe, Co, Ni) by using a detonation decomposition of composite explosives.T he yield of the detonation product obtained after separation and purification is about 10~15%. 2.Experimental Iron/cobalt/nickel nitrate, anhydrous alcohol, carbamide and pentaerythritol tetranitrate/ cyclonite powder (PETN/RDX) were used as received.All the chemical agents are analytical grade.The mixed precursors are consisted of a certain mole number
Raman shift/cm -1 Ni@C Fig.3 Raman spectra of the Fe@C,Co@C,Ni@C nanopaticles Table1 the RS spectra data for the CEMNPs Sample D-band G-band I(D)/I(G) Fe@C 1346 1598 1.08 Co@C 1369 1580 0.94 Ni@C 1351 1610 0.81 4.Conlusions The CEMNPs with the core/shell structure have been synthesized by a detonation technique using of the different composite explosives.Well crytallized bcc-Fe,fcc-Co and fcc-Ni nanocr ystal were coated in graphitic carbon with perfect core/shell structure and with a grain size in the range of 10-20nm.Both graphitic and amorphous carbon occured in the outsidecarbon shell layers that showed by Raman spectroscopy.So the different composite explosives were specially designed for synthesizing CEMNPs nanomaterials.

The selection of support depends on pore size, specific surface area, number of active sites and the value of point of zero charge (PZC).
Calcination temperature led to increase in the grain boundaries thus particle size increase as a function of calcination temperature.

The morphology and micro- ∗ Corresponding author, Tel. 86-571-87951408, E-mail: yanghui@zju.edu.cn Table 1 Batch composition of samples (wt%) Sample number 95-alumina zircon ziconia 1 # 100 0 0 2 # 99 0 1 3 # 98 0 2 4 # 97 0 3 5 # 90 0 10 6 # 99.5 0.5 0 7 # 98.5 1.5 0 8 # 97 3 0 9 # 95 5 0 structure analysis of the samples were observed by HITACHI-570 and Cambridge stereoscan-600 scanning electron microscopes.
For the sample with the zircon additive, besides the fracture toughness improved by the stress-induced-phase-transformation of ZrO2 and micro-cracks, the effect of zircon on glass phase and the size of grain is also affective on the property improvement of the 95-alumina ceramic.

Secondly, others solid grains' interiors involve some liquid phase, whose size and shape are irregular (Fig. 1(b),(c)).
NA D N i i /)/2( 1∑= − = π Where N is the total number of the solid phase particles in the field of vision, and −D is the average diameter of all the solid phase particles.

If the interface adhesion tends to an ameliorative state, the number and the intensity of the interface slip would be reduced; and the same reason would make the interface relaxation effects occur in higher Fig.3 Temperature dependence of Q -1 in the EB-PVD NiCrAlY coated samples and the substrate.
Different to usual interface relaxation, such as the grain boundary relaxation, no obvious modulus soften effects [13] appears in modulus-temperature curve.

The influence mechanisms of ultrasonic vibration to hot-dip aluminizing include cavitation effect and current effect which can lead to minuteness of crystal grain, gas elimination and homogenizing of organization.
(Subject number: 2007BSB01502) References [1] D.H.