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991.
992.
993.
《International Journal of Hydrogen Energy》2005,30(10):1053-1062
Photocatalytic activity of mesoporous titania supported nickel oxide photocatalyst synthesized by single-step sol–gel (SSSG) process combined with surfactant-assisted template method was investigated for hydrogen evolution from an aqueous methanol solution, in comparison with one prepared by conventional incipient wetness impregnation (IWI) method. In single-step sol–gel process, nickel precursor was introduced into the titania sol prepared with the aid of a surfactant template behaving as pore-controlling agent to attain meso-scaled pore. The single-step sol–gel photocatalyst was experimentally found to enhance the photocatalytic evolution of hydrogen rather than the impregnated one. The optimum level of nickel loading in photocatalytic activity test for single-step sol–gel method was slightly higher than that for incipient wetness impregnation method. Characterization results demonstrated the significant modification of physical characteristics of the single-step sol–gel photocatalyst, anticipated to relating to the observation of higher photocatalytic hydrogen evolution activity. 相似文献
994.
《Energy》2005,30(1):73-83
This paper analyzes the change of aggregated CO2 in China from 1957 to 2000 based on a complete decomposition approach—the logarithmic mean divisia index (LMDI) method. The study indicates that China has achieved a considerable decrease in its CO2 emissions mainly due to improved energy intensity. In addition, fuel switching and renewable energy penetration also exhibit positive effect to the CO2 decrease. 相似文献
995.
《Energy》2005,30(2-4):415-426
This paper presents the impact of oxygen and nitrogen compounds on the lubrication properties of low sulfur diesel fuels. It discusses the most recent results, concerning the influence of adding low amounts of 4 specific types of biodiesel, 5 aliphatic amines, 2 tertiarty amides, 10 mono-carboxylic acid esters, 3 acetoacetates and 7 esters of di-carboxylic acids on the tribological behaviour of the steel-on-steel systems, lubricated with low sulfur automotive diesel fuel. Experiments were carried out on the HFRR (high frequency reciprocating rig). The obtained wear results showed that all the various classes of additives improved fuel lubricity. 相似文献
996.
《Energy》2005,30(9):1551-1576
A detailed review of different applications that have already been investigated with SMARTS, a versatile spectral solar irradiance model, is proposed here. This review provides examples of applications in many different disciplines, for which recent developments are discussed. Three main types of applications are considered, depending on their spectral range. Purely spectral applications encompass the determination of atmospheric constituents, the performance testing of spectroradiometers, and the improvement and validation of reference spectra for the rating of photovoltaic or glazing systems, or for new standards development in the field of weathering and material degradation. Narrow-band applications include the determination of different UV fluxes and of the UV index, and the prediction of illuminance on any horizontal or tilted surface, of the luminous efficacy of direct, diffuse or global radiation, of the photosynthetically active radiation, and of the irradiance transmitted by different bandpass filters. Finally, some specific broadband applications are reviewed: mesoscale predictions of radiation fluxes, evaluation of circumsolar effects in pyrheliometers, performance assessment of broadband radiation models, and turbidity determination from broadband irradiance data. 相似文献
997.
《Journal of power sources》2005,140(1):139-144
The effects of Si particle size and the amount of carbon-based conductive additive (CA) on the performance of a Si anode in a Li-ion battery are investigated by adopting combinations of two different Si particle sizes (20 and 3 μm on average) and CA contents (15 and 30 wt.%), respectively. The CA contains graphitic flakes and nano-sized carbon black. Cyclic voltammetry, charge–discharge tests, scanning electron microscopy and X-ray diffraction establish that the CA content has a profound effect on the cycle-life and irreversible capacity of the Si anode. The former increases, while the latter decreases significantly with increasing CA content. Reducing the particle size of Si, on the other hand, facilitates the alloying/de-alloying kinetics. For instance a cycle-life of over 50 cycles with >96% capacity retention at a charge capacity of 600 mAh per g-Si has been demonstrated by adopting of 30 wt.% CA and 3 μm Si particles. 相似文献
998.
《Journal of power sources》2005,141(1):188-192
A micro-porous polymer electrolyte based on PVA was obtained from PVA–PVC based polymer blend film by a novel preferential polymer dissolution technique. The ionic conductivity of micro-porous polymer electrolyte increases with increase in the removal of PVC content. Finally, the effect of variation of lithium salt concentration is studied for micro-porous polymer electrolyte of high ionic conductivity composition. The ionic conductivity of the micro-porous polymer electrolyte is measured in the temperature range of 301–351 K. It is observed that a 2 M LiClO4 solution of micro-porous polymer electrolyte has high ionic conductivity of 1.5055 × 10−3 S cm−1 at ambient temperature. Complexation and surface morphology of the micro-porous polymer electrolytes are studied by X-ray diffraction and SEM analysis. TG/DTA analysis informs that the micro-porous polymer electrolyte is thermally stable upto 277.9 °C. Chronoamperommetry and linear sweep voltammetry studies were made to find out lithium transference number and stability of micro-porous polymer electrolyte membrane, respectively. Cyclic voltammetry study was performed for carbon/micro-porous polymer electrolyte/LiMn2O4 cell to reveal the compatibility and electrochemical stability between electrode materials. 相似文献
999.
《Journal of power sources》2005,144(1):107-112
Research and development was conducted on a proton exchange membrane (PEM) fuel cell stack to demonstrate the capabilities of Ionomem Corporation's composite membrane to operate at 120 °C and ambient pressure for on-site electrical power generation with useful waste heat. The membrane was a composite of polytetrafluoroethylene (PTFE), Nafion®, and phosphotungstic acid. Studies were first performed on the membrane, cathode catalyst layer, and gas diffusion layer to improve performance in 25 cm2, subscale cells. This technology was then scaled-up to a commercial 300 cm2 size and evaluated in multi-cell stacks. The resulting stack obtained a performance near that of the subscale cells, 0.60 V at 400 mA cm−2 at near 120 °C and ambient pressure with hydrogen and air reactants containing water at 35% relative humidity. The water used for cooling the stack resulted in available waste heat at 116 °C. The performance of the stack was verified. This was the first successful test of a higher-temperature, PEM, fuel-cell stack that did not use phosphoric acid electrolyte. 相似文献
1000.
《Energy Policy》2013
Nigeria's economy is largely dependent on petroleum, yet the country is suffering from fuel supply shortages. In response to the transportation fuel supply difficulties in Nigeria, the country released the Nigerian Biofuel Policy and Incentives in 2007 to create favorable investment climate for the entrance of Nigeria into the biofuel sector. The paper assessed the progress made thus far by Nigeria, 4 years after the Nigerian biofuel was released in an attempt to answer the question whether the policy is adequate to transform Nigeria into a biofuel economy. The study found that little progress has been made, which includes commencement of the construction of 20 bioethanol factories, installation of biofuel handling facilities at two depots (Mosimi and Atlas Cove), and selection of retail outlets for biofuel/conventional fuel mix. The site construction of the announced biofuel projects is now slow and other progress is marginal. We therefore conclude that the Nigerian biofuel policy is unlikely to transform Nigeria into a biofuel economy unless the Government revert and refocus on biofuel and include additional financial incentives such as grants and subsidy to complement the tax waivers (income, import duty, VAT), loans, and insurance cover contained in the policy. 相似文献