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781.
782.
Detection of amount and activity of living algae in fresh water by dehydrogenase activity (DHA) 总被引:2,自引:0,他引:2
A study was performed to determine the amount and activity of living algae in fresh water by measuring the dehydrogenase activity (DHA) of algae in order to provide a method to assess the effect of algicide treatment. The conditions of measurement were researched with respect to incubating temperature and duration, and selection of extractants. The comparison between this method and an alternative method, chlorophyll a, shows that this method is simple and easy to practice, and can determine the effect of algicide treatment. 相似文献
783.
The function of estuary wetland on hydrological adjustment and flooding control is studied in this paper,It is estimated that the evapotranspiration in reed field during growth season(June to October)is 722.9 mm,which is 37.5% igher than large water body(E601:525.9mm).The water replacement rate in the reed field can reach 95% only when the rains continously for 11 days and the precipitation reached 912mm.For the water balance in the paddy field ,the total water requirement ranges between 1920 and 1860 mm,among which,31% is from precipitation,and the left is provided by reseroirs.The water usage efficiency is 0.35% at present productivity.Based on the landscape storage area;flooding discharge area;flood diversion area in emergency;and flood control drainage area. 相似文献
784.
Effects of plant species coexistence on soil enzyme activities and soil microbial
community structure under Cd and Pb combined pollution 总被引:5,自引:1,他引:5
The relationship between plant species coexistence and soil microbial communities under heavy metal pollution has attracted much
attention in ecology. However, whether plant species coexistence could o set the impacts of heavy metal combined pollution on soil
microbial community structure and soil enzymes activities is not well studied. The modified ecological dose model and PCR-RAPD
method were used to assess the e ects of two plant species coexistence on soil microbial community and enzymes activities subjected
to Cd and Pb combined stress. The results indicated that monoculture and mixed culture would increased microbe populations under
Cd and Pb combined stress, and the order of sensitivity of microbial community responding to heavy metal stress was: actinomycetes
> bacteria > fungi. The respirations were significantly higher in planted soil than that in unplanted soil. The plant species coexistence
could enhance soil enzyme activities under Cd and Pb combined. Furthermore, planted soil would be helpful to enhance soil genetic
polymorphisms, but Cd and Pb pollution would cause a decrease on soil genetic polymorphisms. Mixed culture would increase
the ecological dose 50% (ED50) values, and the ED50 values for soil enzyme activities decreased with increasing culture time. The
dehydrogenase was most sensitive to metal addition and easily loses activity under low dose of heavy metal. However, it was di cult
to fully inhibit the phoshpatase activity, and urease responded similarly with phosphatase. 相似文献
785.
膨胀石墨除油机理及影响因素研究 总被引:2,自引:0,他引:2
针对水面浮油的去除问题,通过对新型吸附材料-膨胀石墨的扫描电镜观察,从其结构特征的角度揭示了膨胀石墨的吸油机理,首次系统地研究了温度、时间、pH等操作条件对吸附油性能的影响。扫描电镜的结果显示膨胀石墨的鳞片厚度都在100 nm以上,而且以大孔、超大孔为主,这种结构赋予了膨胀石墨独特的吸附特性。操作条件对膨胀石墨的吸附性能有重要的影响,在本实验条件下即在酸(中)性条件下,吸附时间1 min-2 min左右,转速为660 r/min膨胀石墨可达到饱和吸附量。 相似文献
786.
处理好发展经济与保护环境的关系,尤其是项目建设与节能减排的关系,这是实现可持续发展的关键。近年来,一些地区和城市,把节能减排作为促进科学发展的重要手段,推进经济可持续发展,取得了可喜的成绩。但是,也存在着不少障碍。在肯定对节能减排初见成效的基础上,对节能减排障碍进行了剖析,为了加大节能减排与环境保护力度,阐述了国家节能减排的行业政策,提出了节能减排的十项路径选择。 相似文献
787.
Ning Wei Yang Chen Kun Cai Yingyan Zhang Qingxiang Pei Jin-Cheng Zheng Yiu-Wing Mai Junhua Zhao 《绿色能源与环境(英文)》2022,7(1):86-94
Graphene is a two-dimensional material that can be folded into diverse and yet interesting nanostructures like macro-scale paper origami.Folding of graphene not only makes different morphological configurations but also modifies their mechanical and thermal properties. Inspired by paper origami, herein we studied systemically the effects of creases, where sp2 to sp3 bond transformation occurs, on the thermal properties of graphene origami using molecular dynamics(MD) simula... 相似文献
788.
针对盐州330 kV变电站330 kV 1号、2号主变压器温升异常,带载能力不足问题,通过对变压器冷却器实体检查及温升实测值与理论计算对比分析,找出问题原因并提出了解决方案。分析及应用结果表明:变压器带载能力不足是由冷却器散热效率太低引起,更新冷却器后,变压器温升及带载能力达到额定要求,变压器恢复安全稳定运行。 相似文献
789.
Liu Pei Lin Deng-Fung Wang Wei-Jhu 《Journal of Material Cycles and Waste Management》2022,24(4):1251-1266
Journal of Material Cycles and Waste Management - In this study, two dosages of slag aggregate replacement were adopted to evaluate their effect on performance of asphalt concrete through lab tests... 相似文献
790.
Gan Lin Huang Guanxing Pei Lixin Gan Yanjing Liu Chunyan Yang Mingnan Han Dongya Song Jiangmin 《Environmental science and pollution research international》2022,29(12):17031-17048
Environmental Science and Pollution Research - High concentration of nitrate (NO3?) in groundwater is a major concern because of its complex origin and harmful effects on human health. This... 相似文献