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791.
社区参与旅游发展运行框架的初步研究 总被引:2,自引:0,他引:2
社区参与旅游发展是旅游可持续发展宏观系统中不可或缺的机制。提出了社区参与旅游的新目标观、新组织观、新系统观等理念,并尝试运用区域经济学的理论,对社区参与旅游发展运行框架进行了新的探讨,旨在为我国社区参与的有效实施和社区旅游的可持续发展提供借鉴。 相似文献
792.
793.
Zichao Lian Donglai Pan Wenchao Wang Dieqing Zhang Guisheng Li Hexing Li 《环境科学学报(英文版)》2017,29(10):108-113
A solar-light double illumination photoelectrocatalytic cell(SLDIPEC) was fabricated for autonomous CO_2 reduction and O_2 evolution with the aid of photosystem II(PS-II, an efficient light-driven water-oxidized enzyme from nature) and utilized in a photoanode solution. The proposed SLPEC system was composed of Cu foam as the photoanode and p-Si nanowires(Si-NW) as the photocathode. Under solar irradiation, it exhibited a super-photoelectrocatalytic performance for CO_2 conversion to methanol, with a high evolution rate(41.94 mmol/hr), owing to fast electron transfer from PS-II to Cu foam.Electrons were subsequently trapped by Si-NW through an external circuit via bias voltage(0.5 V), and a suitable conduction band potential of Si(-0.6 e V) allowed CO_2 to be easily reduced to CH_3 OH at the photocathode. The constructed Z-scheme between Cu foam and Si-NW can allow the SLDIPEC system to reduce CO_2(8.03 mmol/hr) in the absence of bias voltage. This approach makes full use of the energy band mismatch of the photoanode and photocathode to design a highly efficient device for solving environmental issues and producing clean energy. 相似文献
794.
铁有机骨架材料的快速合成及对阴离子染料的吸附性能 总被引:5,自引:2,他引:3
染料废水色度高,难以生化处理,吸附法是有色废水处理的重要方法.采用常温快速合成铁有机骨架材料,通过IR和XRD对合成的材料进行表征;并研究铁有机骨架材料对阴离子染料的吸附性能.结果表明常温快速反应能够合成铁有机骨架材料,材料比表面积和孔体积较高,等电点p H为3.7.铁有机骨架材料在酸性条件下更容易吸附水中的阴离子染料;随染料浓度的增加,材料对染料的吸附量逐渐增大,Langmuir恒温吸附模型可以很好描述该过程,计算的吸附参数表明吸附过程容易进行.材料对染料的吸附为准二级动力学,染料结构会显著影响铁骨架材料吸附过程,络合结构的偶氮染料能够快速达到吸附平衡. 相似文献
795.
Effects of free iron oxyhydrates (Fed) and soil organic matter (SOM) on copper (Cu2+) sorption-desorption behavior by size fractions of aggregates from two typical paddy soils (Ferric-Accumulic Stagnic Anthrosol (Soil H) and Gleyic Stagnic Anthrosol (Soil W)) were investigated with and without treatment of dithionite-citrate-bicarbonate and of H2O2. The size fractions of aggregates were obtained from the undisturbed bulk topsoil using a low energy ultrasonic dispersion procedure. Experiments of equilibrium sorption and subsequent desorption were conducted at soil water ratio of 1:20, 25℃. For Soil H, Cu2+ sorption capacity of the DCB-treated size fractions was decreased by 5.9% for fine sand fraction, by 40.4% for coarse sand fraction, in comparison to 2.9% for the bulk sample. However, Cu2+ sorption capacities of the H2O2-treated fractions were decreased by over 80% for the coarse sand fraction and by 15% for the clay-sized fraction in comparison to 88% for bulk soil. For Soil W, Cu2+ sorption capacity of the DCB-treated size fraction was decreased by 30% for the coarse sand fraction and by over 75% for silt sand fraction in comparison to 44.5% for the bulk sample. Cu2+ sorption capacities of the H2O2-treated fractions were decreased by only 2.0% for the coarse sand fraction and by 15% for the fine sand fraction in comparison to by 3.4% for bulk soil. However, Cu2+ desorption rates were increased much in H2O2-treated samples by over 80% except the clay-sized fraction (only 9.5%) for Soil H. While removal of SOM with H2O2 tendend to increase desorption rate, DCB- and H2O2-treatments caused decrease in Cu2+ retention capacity of size fractions. Particularly, there hardly remained Cu2+ retention capacity by size fractions from Soil H after H2O2 treatment except for clay-sized fraction. These findings supported again the dominance of the coarse sand fraction in sorption of metals and the preference of absorbed metals bound to SOM in differently stabilized status among the size fractions. Thus, enrichment and turnover of SOM in paddy soils may have great effects on metal retention and chemical mobility in paddy soils. 相似文献
796.
将壳聚糖、聚醚多元醇、甲苯二异氰酸酯混合发泡,制备了壳聚糖/聚氨酯(Cs/PU)多孔复合材料,利用原子吸收光谱研究了Cs/PU对水中Cu2+、Cd2+的吸附能力。结果表明:在28℃条件下,当吸附时间为30min,溶液pH=4~5时,Cu2+的最高去除率为96.67%,溶液pH=6~7时,Cd2+的去除率为95.67%。Cd2+、Cu2+的饱和吸附率容量分别为28.78mg/g和25.32mg/g。两种金属离子共存时,Cs/PU对Cu2+的选择性大于Cd2+。 相似文献
797.
主要研究了不同浓度的Cu^2+对螺旋藻生长的影响,结果表明:Cu^2+浓度为0.079mg/L时对螺旋藻的生长具有明显的促进作用,当浓度大于0.395mg/L时则对螺旋藻的生长产生抑制作用,而且抑制作用随着铜离子浓度的增加而增强;铜离子对螺旋藻的完全抑制质量浓度为39.50mg/L。 相似文献
798.
799.
800.
A series of single-phase T-structured NdSrCu1??xCoxO4?? with oxygen vacancies and T0-structured Sm1:8Ce0:2Cu1??xCoxO4?? (x:
0–0.4) with oxygen excess were prepared using ultrasound-assisted citric acid complexing method, and characterized by means of
techniques such as thermogravimetric analysis and NO temperature-programmed desorption (NO-TPD). The catalytic activities of these
materials were evaluated for the decomposition of NO. It was found that the NdSrCu1??xCoxO4?? catalysts were of oxygen vacancies
whereas the Sm1:8Ce0:2Cu1??xCoxO4?? ones possessed excessive oxygen (i.e., over-stoichiometric oxygen); with a rise in Co doping level,
the oxygen vacancy density of NdSrCu1??xCoxO4?? decreased while the over-stoichiometric oxygen amount of Sm1:8Ce0:2Cu1??xCoxO4??
increased. The NO-TPD results revealed that NO could be activated much easier over the oxygen-deficient perovskite-like oxides
than over the oxygen-excessive perovskite-like oxides, with the NdSrCuO3:702 catalyst showing the best e ciency in activating NO
molecules. Under the conditions of 1.0% NO/helium, 2800 hr??1, and 600–900°C, the catalytic activity of NO decomposition followed
the order of NdSrCuO3:702 > NdSrCu0:8Co0:2O3:736 > NdSrCu0:6Co0:4O3:789 > Sm1:8Ce0:2Cu0:6Co0:4O4:187 > Sm1:8Ce0:2Cu0:8Co0:2O4:104
> Sm1:8Ce0:2CuO4:045, in concord with the sequence of decreasing oxygen vacancy or oxygen excess density. Based on the results,
we concluded that the higher oxygen vacancy density and the stronger Cu3+/Cu2+ redox ability of NdSrCu1??xCoxO4?? account for the
easier activation of NO and consequently improve the catalytic activity of NO decomposition over the catalysts. 相似文献