The removal and recovery of phosphate from water using adsorption technology require that the adsorbent material is easily separable from treated water. Continuous efforts are still awaited to develop additional efficient phosphate adsorbents that are economical to fabricate. In this study, hydrous zirconia-impregnated chitosan beads (HZCB) containing different Zr/chitosan ratios were synthesized using a facile scheme. We found that HZCB with a Zr/amine molar ratio of?~?1 (HZCB-1) possessed excellent stability and phosphate removal performance. This optimized material was characterized with XRD, SEM, FTIR, XPS, specific surface area and point of zero charge measurements. The maximum adsorption capacity was 42.02 mg/g (at pH?~?6.7). The adsorption kinetics were best described by a pseudosecond-order model, and the rate constant of HZCB-1 was much lower than that of its powder but was similar to the commercial bead product Ferrolox. The removal of phosphate depended substantially upon pH and was enhanced by lowering the pH. Good selectivity of HZCB-1 for phosphate was observed, although the coexistence of sulfate produced a significant negative effect. Direct coordination of phosphate to Zr atoms by replacing hydroxyls was the dominant adsorption mechanism (~?85%), while chitosan also contributed to phosphate removal (~?15%). Adsorbed phosphate was successfully eluted by an NaOH solution, and the material obtained after desorption and regeneration was able to be repeatedly used. The results of column studies indicated that this material could be implemented in long-term application.
Compared to the traditional transition metal layered double hydroxides, transition metal layered carbonate double hydroxides (TMC-LDHs) possess superior electrochemical performance in theory. But TMC-LDHs have not received its deserved attention, especially for application in the energy storage field. In this work, a flower-like TMC-LDH (Ni0.75Co0.25(CO3)0.125(OH)2, NCCO) material was successfully prepared by hydrothermal method, which exhibits a high specific capacity of 306.8 mAh g−1 (0.52 mAh cm−2) at 0.5 A g−1 with capacity retention of 70.5 % after 2000 cycles. The solid-state hybrid supercapacitor device NCCO//PVA/KOH//IHPC based on the prepared NCCO material and an interconnected hierarchical porous carbon (IHPC) delivers a high specific energy of 50.96 Wh kg−1 at a specific power of 1.06 kW kg−1, and a high specific energy of 36.39 Wh kg−1 still can be delivered at a high specific power of 10.49 kW kg−1. More than 181.2 % of initial specific capacity is retained after 12000 cycles. The specific energy, energy retention under large specific power, and the cycle stability of the assembled device are better than most of the solid-state hybrid supercapacitors that have been reported. These results demonstrate the promising prospect of the TMC-LDH material in the practical application in advanced solid-state supercapacitors. 相似文献
Motion is a common phenomenon in the real world so the consistence of virtual and real motion is one of hot focuses in augmented reality system. This paper mainly analyzes virtual and real motion blur consistence in augmented reality system, and mainly do improvement in two aspects, one is how to get the motion blur parameters, the other is how to render motion blur. From the available literature it can be seen that, most achieved methods to get motion blur parameters are based on machine vision. But this paper first acquires the motion trajectory by magnetic tracking, and then gets motion blur parameters. Considering the available literature on motion blur rendering methods, they mainly contain convolution and accumulator caching and so on. Due to rotation translation compound motion blur, this paper does rendering in advance based on improved mathematical model, and then render virtual object through looking up table in augmented reality system. Experimental results show that the new virtual and real motion blur consistence render algorithm has low time complexity and achieve the desired effect in simulation environment and real scenes. 相似文献
Multi-walled carbon nanotubes (MW-CNTs) were prepared by chemical vapor deposition (CVD) method with the decomposition of acetylene over Co/SiO2 catalyst. TG-DTA technique was used together with TEM and XRD to study the effect of reaction temperature on the composition, graphitized extent, and diameter distribution of the produced raw CNTs based on their oxidization resistance. During the decomposition, the micro-crystallite of the active constituent (Co/SiO2) were growing up as the reaction temperature rising. This in turn resulted in an increase of the diameter distribution range of produced MW-CNTs. The average diameter increased from 20~30 nm (650℃) to 30~50 nm (750℃). XRD results also showed the graphitized extent of MW-CNTs was enhanced meanwhile the spacing between the layers (d002) decreased from 3.45 (650℃) to 3.32 (850℃) with the reaction temperature raised. TG-DTA data showed that the exothermic peak of the amorphous carbon was below 380℃and its content would decrease as temperature increasing. In summary, for CVD production of CNTs using acetylene gas on Co/SiO2 catalyst, low temperature (about 650℃) favored producing thinner MW-CNTs with the diameter from 20 to 30 nm while higher temperature (about 850℃) is favored thicker MW-CNTs (diameter from 70 to 100 nm). 相似文献