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841.
A polyaluminum containing a high concentration of Al13 polymer and active chlorine (PACC) was successfully synthesized by a new electrochemical reactor using Ti/RuO2-TiO2 anodes. PACC can potentially be used as a dual-function chemical reagent for water treatment. The obtained results indicated that the formation of Al13 polymer and active chlorine, were the most active components in PACC responsible for coagulation and disinfection respectively. These components were significantly influenced by electrolyte temperature, current density, and stirring rate. It was observed that high electrolyte temperature favored the formation of Al13. Increasing current density and stirring rate resulted in high current efficiency of chlorine evolution, thus favoring the generation of Al13 and active chlorine in PACC. When the PACC (AlT = 0.5 mol/L, basicity = 2.3) was prepared at the optimum conditions by electrolysis process, the Al13 polymer and active chlorine in product reached above 70% of AlT and 4000 mg/L, respectively. In the pilot scale experiment with raw polyaluminum chloride used as an electrolyte, PACC was successfully prepared and produced a high content of Al13 and active chlorine products. The pilot scale experiment demonstrated a potential industrial approach of PACC preparation. 相似文献
842.
The adsorption behaviors of ammonium ions from aqueous solution by a novel bioadsorbent,the Boston ivy (Parthenocissus tricuspidata) leaf powder (BPTL) were investigated.The SEM images and FT-IR spectra were used to characterize BPTL.The mathematical models were used to analyze the adsorption kinetics and isotherms.The optimum pH range for ammonium adsorption by BPTL was found to be 5-10.The adsorption reached equilibrium at 14 hr,and the kinetic data were well fitted by the Logistic model.The intraparticle diffusion was the main rate-controlling step of the adsorption process.The high temperature was favorableto the ammonium adsorption by BPTL,indicating that the adsorption was endothermic.The adsorption equilibrium fitted well to both the Langrnuir model and Freundlich model,and the maximum monolayer adsorption capacities calculated from Langmuir model were 3.37,5.28 and 6.59 mg N/g at 15,25 and 35℃,respectively,which were comparable to those by reported minerals.Both the separation factor (RL) from the Langmuir model and Freundlich exponent (n) suggested that the ammonium adsorption by BPTL was favorable.Therefore,the Boston ivy leaf powder could be considered a novel bioadsorbent for ammonium removal from aqueous solution. 相似文献
843.
Numerous studies have focussed on the relationship between female choice and the multiple exaggerated sexual traits of males.
However, little is known about the ability of males to actively enhance specific components of their display in response to
the loss of one component. We investigated the capacity of male satin bowerbirds (Ptilonorhynchus violaceus) to respond to the loss of one of their sexual signals by performing an experiment in which we removed decorations at their
bowers. We found that males compensated for decoration loss by increasing bower construction behaviour and decreasing their
latency to bower painting. These results are novel because they suggest that males can assess the quality of their own display
and make decisions about how to augment their displays. We discuss these results in the context of previous studies of mate
choice in satin bowerbirds, as both of the supplementary behaviours we observed are known correlates of male mating success. 相似文献
844.
当前中国经济快速增长很大程度是以过度消耗资源、牺牲环境为代价的.生态环境污染严重影响经济的可持续发展,生态问题制约着和谐社会的构建.生态建设已成为协调经济、社会和生态发展,走可持续发展的唯一出路.当前由于政府主导型生态建设出现众多问题,诸如生态环境脆弱、压力大,法律法规不完善,生态建设资金投入少、投入渠道单一,生态治理工程效益有待继续提高等等.因此,倡导企业、农民、专家、投资者和志愿组织、社会团体等积极参与到生态建设中来,并建立激励机制对各参与者实施相应的激励措施,使他们充分发挥能动性,更快、更好的进行生态建设. 相似文献
845.
846.
847.
单歧藻对烷基酚类化合物的生物降解性研究 总被引:1,自引:0,他引:1
以4-乙基酚为研究对象,研究其在单歧藻作用下的可降解性及其影响因素,然后对邻甲酚,间甲酚,4-辛基酚的生物降解动力学进行了比较,最后运用生物降解数据logK对8种烷基酚类化合物进行了结构-生物降解性(QSBR)的研究。研究结果表明:单歧藻对烷基酚类化合物的降解速率与藻细胞浓度和有机物初始浓度有关,化合物的降解动力学常数K值由污染物的初始浓度所决定,化合物的疏水性参数logKOW、分子量MW、一级价键连接指数1XV、二级价键连接指数2XV、生成热ΔHf和分子偶极距μ能够较好地拟合烷基酚类化合物的生物降解速率,其中2XV拟合效果最好。并在此基础上,初步分析了烷基酚类化合物的生物降解机理,认为空间参数是决定其生物降解的主要因素,化合物的生成热和电性参数μ、Ehomo的影响也不可忽视。 相似文献
848.
Mikołaj Urbanowski Paweł Socha Paweł Dąbrowski Wioletta Nowaczewska Anna Sadakierska-Chudy Tadeusz Dobosz Krzysztof Stefaniak Adam Nadachowski 《Die Naturwissenschaften》2010,97(4):411-415
An upper second permanent molar from a human was found alongside numerous tools of the Micoquian tradition and was excavated
in Stajnia Cave, which is located over 100 km North of the Carpathian Mountains in southern Poland. The age of these finds
has been established within a time-span of late Saalian to early Weichselian, most likely to OIS 5c or 5a, according to the
palaeontological, geological, archaeological and absolute dating of the layer from which they were obtained. An examination
of the morphology of the human molar indicates that this tooth exhibits many traits frequently occurring in Neanderthal upper
molars. Although the occurrence of derived Neanderthal traits in the Stajnia molar cannot be firmly established because of
degradation of its cusps, the presence of the above-mentioned features allows the assertion that this tooth belonged to a
Neanderthal. The age of the Stajnia tooth and the archaeological context of this find also indicate that this molar is of
Neanderthal origin. 相似文献
849.
压缩天然气加气母站安全评价中若干问题的探讨 总被引:1,自引:0,他引:1
针对加气母站安全评价中存在的安全许可方式分类、设计适用标准选择、消防系统设计、移动重大危险源辨识等方面的问题进行了分析和探讨,提出了一些参考性的想法和建议,以便更好地统一和规范加气母站的安全评价工作。 相似文献
850.