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921.
922.
科学合理的评估方法体系对于环境规划的实施绩效起着不可替代的作用。为更有效地开展环境规划实施效果的评估,总结国内外关于环境规划实施效果的评估方法,重点概述了对比分析、逻辑框架、环境经济预测分析、环境绩效评估等评估方法。并对这几类方法进行了对比分析,剖析各方法应用的区域范围、评估的步骤、优点和局限性及评估重点等,总结出建立有效的环境规划实施效果评估方法体系,需要综合各种方法,并就具体的环境规划而言,选择合适方法,综合运用,为环境规划实施效果评估的深入开展和具体实施提供理论依据。 相似文献
923.
924.
Yuchun Qi Xinchao Liu Yunshe Dong Qin Peng Yating He Liangjie Sun Junqiang Ji Congcong Cao 《环境科学学报(英文版)》2014,26(4):834-845
We examined the effects of simulated rainfall and increasing N supply of different levels on CO2 pulse emission from typical Inner Mongolian steppe soil using the static opaque chamber technique, respectively in a dry June and a rainy August. The treatments included NH4NO3 additions at rates of 0, 5, 10, and 20 g N/(m2.year) with or without water. Immediately after the experimental simulated rainfall events, the CO2 effluxes in the watering plots without N addition (WCK) increased greatly and reached the maximum value at 2 hr. However, the efflux level reverted to the background level within 48 hr. The cumulative CO2 effluxes in the soil ranged from 5.60 to 6.49 g C/m2 over 48 hr after a single water application, thus showing an increase of approximately 148.64% and 48.36% in the efftuxes during both observation periods. By contrast, the addition of different N levels without water addition did not result in a significant change in soil respiration in the short term. Two-way ANOVA showed that the effects of the interaction between water and N addition were insignificant in short-term soil COz efftuxes in the soil. The cumulative soil CO2 fluxes of different treatments over 48 hr accounted for approximately 5.34% to 6.91% and 2.36% to 2.93% of annual C emission in both experimental periods. These results stress the need for improving the sampling frequency after rainfall in future studies to ensure more accurate evaluation of the grassland C emission contribution. 相似文献
925.
Jiao He Guoli Zi Zhiying Yan Yongli Li Jiao Xie Deliang Duan Yongjuan Chen Jiaqiang Wang 《环境科学学报(英文版)》2014,26(5):1195-1202
Cyanobacteria, which occurred in eutrophic water harvest solar light to carry out photosynthesis with high efficiency. In this work, cyanobacteria (Microcystis sp.) were used as biotemplate to synthesize titania structure. The synthesized titania sample had similar morphology to that of the original template in spite of the fragile unicellular structures and extremely high water content of cyanobacterial cells. Incorporation of biogenic C, as well as the morphology inherited from biotemplate improved visible- light absorbance of the titania structure. The sample exhibited higher visible-light photocatalytic activity than commercial titania photocatalyst Degussa P25 for Rhodamine B (RhB) degradation. Compared with those C-doped titania photocatalysts prepared by other methods, cyanobacteria templated titania photocatalyst offer some potential for competitive advantages. The reported strategy opened up a new use for the cyanobacteria. It could also be used for titania in applications such as treatment of polluted water, dye-sensitized solar cells, or other regions. 相似文献
926.
Quantification of viable bacteria in wastewater treatment plants by using propidium monoazide combined with quantitative PCR (PMA-qPCR) 总被引:1,自引:0,他引:1
The detection of viable bacteria in wastewater treatment plants(WWTPs) is very important for public health, as WWTPs are a medium with a high potential for waterborne disease transmission. The aim of this study was to use propidium monoazide(PMA) combined with the quantitative polymerase chain reaction(PMA-qPCR) to selectively detect and quantify viable bacteria cells in full-scale WWTPs in China. PMA was added to the concentrated WWTP samples at a final concentration of 100 μmol/L and the samples were incubated in the dark for 5 min, and then lighted for 4 min prior to DNA extraction and qPCR with specific primers for Escherichia coli and Enterococci, respectively. The results showed that PMA treatment removed more than 99% of DNA from non-viable cells in all the WWTP samples, while matrices in sludge samples markedly reduced the effectiveness of PMA treatment. Compared to qPCR, PMA-qPCR results were similar and highly linearly correlated to those obtained by culture assay, indicating that DNA from non-viable cells present in WWTP samples can be eliminated by PMA treatment, and that PMA-qPCR is a reliable method for detection of viable bacteria in environmental samples. This study demonstrated that PMA-qPCR is a rapid and selective detection method for viable bacteria in WWTP samples, and that WWTPs have an obvious function in removing both viable and non-viable bacteria. The results proved that PMA-qPCR is a promising detection method that has a high potential for application as a complementary method to the standard culture-based method in the future. 相似文献
927.
928.
通过对当前应急救援队伍的装备配置和维护保养情况进行调查,结合基层队伍的专项训练情况,分析现阶段应急救援队伍应急保障中存在的薄弱点,就如何提高应急救援队伍的救援能力提出建议。 相似文献
929.
pH值对易腐有机垃圾厌氧发酵产物分布的影响 总被引:23,自引:4,他引:19
易腐有机垃圾的厌氧发酵(水解和酸化)程度和发酵类型受pH值的影响.批式实验结果表明:发酵液pH=7时有利于微生物的生长繁殖,从而促进碳水化合物的水解和酸化过程,还能促进可溶性蛋白的酸化过程.在不同pH值条件下,易腐有机垃圾的基本发酵类型为:pH=7时主要进行丁酸发酵;pH=8时丁酸发酵类型逐渐占优势;而pH=5时丙酸发酵类型逐渐占优势.乳酸是酸化初期的主要产物,但在发酵液的pH=5和pH=7条件下,乳酸可被微生物进一步代谢,而pH=8时乳酸却未能被代谢.在酸化初期醇的产生量大于挥发性脂肪酸,酸化后期pH=5和pH=7时挥发性脂肪酸与醇产生量比值为1.2~1.5∶1,而pH=8时两者比值为1.6~2.5∶1.pH为5、7和8三者的水解速率常数kh分别为0.000 8 h-1、0.000 9 h-1和0.000 2h-1.pH=7在反应时间t>100 h以后,发酵液中可溶态总有机碳全部由酸化产物组成,酸化完全;而pH=5和pH=8达到酸化完全的反应时间分别为t>300 h和t>600 h. 相似文献
930.
Comparison of catalytic activity of two platinised TiO2 films towards the oxidation of organic pollutants 总被引:2,自引:0,他引:2
Two types of platinised TiO2 films, i.e., Pt-TiO2/ITO and Pt(TiO2)/ITO, were prepared by a procedure of dip-coating and subsequent photo-deposition, and photo-deposition and subsequent dip-coating, respectively. They were well characterized by DRS, XRD spectra, SEM microscopy and photoelectrochemical measurement. Their photocatalytic, dark catalytic and photoelectrocatalytic activities were investigated using formic acid as a model organic pollutants. Compared with pure TiO2/ITO film, the photocatalytic activity of the platinised TiO2 films were apparently improved. However, the improvement was considerably dependent on the preparation method of these films. Pt-TiO2/ITO not only possessed higher photocatalytic activity but also showed a dark catalytic activity towards HCOOH degradation. As a sequence, it was first emphasized that the dark catalytic effect of Pt-TiO2/ITO was partly responsible for degradation of formic acid in the photocatalytic oxidation process. Although the Pt(TiO2)/ITO film does not exhibit the dark catalytic activity, its photocatalytic degradation efficiencies towards HCOOH are higher than that of Pt-TiO2/ITO film. Therefore, in view of enhanced photocatalytic activity, the Pt(TiO2)/ITO was more favored than Pt-TiO2/ITO film. 相似文献