Papers by Keyword: Carbon

Abstract: In order to clarify the initial growth of the truffle environmental conditions, the use of PDA plus rich liquid medium, shaking method, its growth temperature, pH, humidity, moisture, illumination and the several other ecological factors is tested. The results show that the optimum temperature of the growth stage is 22-24 °C,Mycelium biomass is 1.45-1.56 g•L-1 .but the latter part of truffle formation temperature can be appropriately higher, at 25-30 °C, which is consistent with the natural temperature. PH at 6.8-7.5 in conditions is comparetively suitable for truffle growth , Mycelium biomass is 1.57-1.58 g•L-1,but alsobetter in the slightiy alkaline conditions than in the acidic environment ,which is different from the other fungi.It is suitable for its growth at about 35% moisture content and humidity of 80-85% mycelium growth is 90.1% , too much water is not conducive to truffle growth and development, so the truffle needs to loose and slightly moist soil in the growth and development. Truffle needs not too much illumination a day, 2h scattering light is enough, mycelium growth is88.7%, too long ilumination , especially in direct sunlight is not conducive to truffle growth. . And citric acid and glucose as the carbon sources, urea and tartaric acid as the nitrogen sources, the amenit of truffle growth, is respectively2.92 g•L-1、2.61 g•L-1，2.35g•L-1、2.26 g•L-1. This further research on the development as well as artificial truffle cultivation provides a theoretical reference.

Abstract: A vapor deposed LiFePO4/C composite cathode material was acquired through filled carbon to FePO4 precursor by vapor deposition. The results showed that the carbon could contact to LiFePO4 nanopaticle directly and uniformly and formed a conducting network. It showed a good discharge capacity retention at large discharge rate. It was 57.3% at 10C. It also showed an excellent capacity steady characteristic when cycling at 1C.

Abstract: LiMn0.7Fe0.3PO4/C composite cathode material was prepared by using a solid state reaction method. The effects of annealing temperatures on the structural and electrochemical performance of LiMn0.7Fe0.3PO4/C were investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), charge–discharge tests and electrochemical impedance spectra (EIS). The results showed that all of samples have pure ordered olivine phase with orthorhombic Pnma structure. The electrochemical performance of LiMn0.7Fe0.3PO4/C can be improved remarkably with increasing temperature from 550oC to 650 oC due to increased crystallization, cation-order and decreased charge transfer resistance. However, increase temperature to 700 oC leads to bigger crystal particle size and decreased cation-order, thus higher resistance and deteriorated electrochemical properties. The sample prepared at optimized temperature of 650 oC presents a remarkable improved electrochemical performance. It delivers an initial capacity of 125.1 mAhg-1 at 0.2C, 95 mAhg-1 at 5C, and a capacity retention of 98.0% after 30 cycles.

Abstract: Fly ash, which is nominally solid wastes generated during the combustion of coal, contains plenty of valuable minerals. Thus, comprehensive recovery of these valuable minerals not only solves environmental pollution problems but also realizes secondary utilization and added values increase of fly ash resources. The Joint process flow of flotation and magnetic separation was adopted in the experiments to recover carbon and iron from fly ash comprehensively, and good technical indexes had been obtained. Flotation separation was conducted on a sort of fly ash whose ignition loss was about 17%. And the ignition loss of concentrates and tailings obtained are above 55% and below 5%, respectively, which can be for further use. Based on the relatively high contents of iron in flotation tailings, magnetic separation for iron enrichment was carried on subsequently. After concentration, the content of Fe₂O₃ in iron concentrate is above 60%.

Abstract: C/C-SiC brake composites, based on reinforcement of carbon fiber and dual matrix of carbon and silicon carbide, were fabricated by warm compacted-in situ reacted process. Rules about the influence of different components on the friction and wear characteristics of the C/C-SiC composites are ascertained. As hard particle, the SiC has the function to the formation of friction film, which is in favor of increasing the coefficient of friction (COF) and decreasing the wear rate. The resin carbon plays the role of enhancing the COF, but they are easy to be cut and increase the wear rate. The graphite plays the lubrication function, and right volume content of graphite is helpful to forming friction film to reduce the wear rate. The C/C-SiC composite fabricated by the warm compacted-in situ reaction can with best tribological performance when the components volume fraction of carbon fibre, SiC, graphite and resin carbon are 15.5%, 37.0%, 22.1% and 20.8%, respectively, which the COF and the wear rate can reach the maximum and the minimun value of 0.44 and 1.1μm/cycle respectively.

Abstract: Dispersion strengthened aluminium composites have been prepared by mechanical alloying. At this work were studied the turning conditions to get in situ formation and dispersion of Al₄C₃ on 2024 alloy by graphite addition. The alloy matrix was obtained by attrition milling a mixture of starting powders; further additions of carbon (2,5; 5 and 10% wt) were performed by means of a planetary mill. Through an adequate sintering the reinforcement formation was showed by X-Ray diffraction analysis of powders with milling times next to 20 hours. The microhardness values appointed that mechanical properties were held even soft material addition (graphite) and improved by age hardening. Pin-on-disc test revealed the composite have low friction coefficient, due to lubricant carbon action and enough low volumetric wear due to high hardness of bulk Al₄C₃ reinforcement.

Abstract: Artificial sponge was used as the template to produce carbon/epoxy resin composites with interpenetrating network structure. Carbon with a network structure was first obtained by the pyrolysis of sponge. The composites were then obtained by injecting epoxy resin into the carbon. Their microstructures, thermal diffusivity, and thermal expansions were analyzed. The results show that the structure of sponge controlled the interpenetrating network structures of the carbon/epoxy resin composites. The composites exhibit a lower coefficient of thermal expansion and a high thermal diffusivity than the epoxy resin.

Abstract: In the present investigation, the Al-C-KCl composite powders were prepared by a ball milling processing in an attempt to improve the hydrogen evolution capacity of aluminum in water. The results showed that the hydrogen generation reaction is affected by KCl amount, preparation processing, initial aluminum particle size and reaction temperature. Increasing KCl amount led to an increased hydrogen generation volume. The use of aluminum powder with a fine particle size could promote the aluminum hydrolysis reaction and get an increased hydrogen generation rate. The reaction temperature played an important role in hydrogen generation rate and the maximum hydrogen generation rate of 44.8 cm3 min-1g-1of Al was obtained at 75oC. The XRD results identified that the hydrolysis byproducts are bayerite (Al(OH)3) and boehmite (AlOOH).

Abstract: Changes of nutrient cycle and balance in agricultural ecosystem will bring heavy impacts not only on land production, but also on ecological and environmental condition. We studied on the balances of main nutrients (carbon, nitrogen and phosphor) and their long-term changes in a typical arable ecosystem in North China, based on the resource data got from household surveys combined with land use data derived from remote sensing imagery. The results show that C and N balances of large-scale irrigated land changed from deficits in 1945 into great surpluses in 2002, respectively, and P surpluses also doubled in 2002. C, N and P balances in overall arable ecosystem showed significant surpluses despite of decreased total arable area after 60 years. Contrarily, C and N fluxes of arable landscape in 1945 showed overall deficits. Nutrient balance changes of arable lands were impacted mainly by anthropogenic factors such as fertilizer input, land productivity crop residue utility and land use.

Abstract: In this paper, a novel carbon/bentonite composite was prepared using sucrose as carbon source and bentonite as raw material. The characterization results shown that plenty of carbon particles distribute on the surface of the composite, and an abundant of functional groups, such as SO₃H, carboxylic and hydroxyl groups, were successfully introduced onto the surface of the prepared composite. The adsorption capacity of the prepared composite for typical heavy metal ions and methylene blue deys also was investigated and compared with activated carbon and bentonite, the results show that the composite shows excellent adsorprion performance for heavy metal ions, and the adsorption capacity for Cu²⁺ and Ni2+ increase by 136% and 591% than natural bentonite, respect^{Superscript text}ively. The prepared composite with excellent adsorption performance could be used as a low-cost alternative to activated carbon for the treatment of heavy metal ions polluted wastewater.