A/O和A2/O法除磷脱氮工艺影响因素及除磷动力学的研究

重点介绍A/O除磷工艺和A~2/O除磷脱氮工艺,以及影响除磷脱氮工艺因素和除磷动力学的研究。工艺研究采用了动态与静态实验方法,采用色质联机研究了有毒有机物的降解情况。试验结果表明,A/O、A~2/O工艺的BOD_5去除率近于二级污水处理厂,A~2/O法TP去除率近于三级污水处理厂,且去除难降解有毒有机物的效率高于传统的活性污泥法。动力学公式的修正使之更适于低碳源的情况。八种影响因素的研究为工艺的设计与运行提供了依据。     

壳聚糖-丙烯酰胺-丙烯酸三元接枝共聚物去除废水中铜离子研究

研究pH值、温度、反应物比率对生成三元接枝共聚物的影响,三元接枝共聚物接枝率与接枝效率的计算,以及三元接枝共聚物对铜离子的吸附效果.实验与计算结果表明：生成三元接枝共聚物的最佳反应条件为引发剂（NH4）2S2O8用量6 mmol/L,反应温度50℃,壳聚糖（CTS）：丙烯酰胺（AM）：丙烯酸（AA）=1∶2.7∶0.3,pH值=7,反应时间5h;在相同条件下,三元接枝共聚物对铜离子去除效果比壳聚糖有了明显的改善,对铜离子去除率最高达到90.06％,比壳聚糖对铜离子的去除率高49.72％.     

AA-HPA-AMPS阻垢剂最佳合成条件研究

通过溶液聚合方法,以丙烯酸、丙烯酸羟丙酯、2-丙烯酰胺-2-甲基丙磺酸为单体,以过硫酸铵为引发剂,合成AA-HPA-AMPS聚合物。固定聚合物浓度为4mg/L,分别考查反应时间、反应温度(X1)、引发剂用量(X2)、单体配比(X3)对聚合物阻CaCO3垢性能的影响,并设计了正交实验,得出聚合物在90℃、引发剂用量为13.5%、M(AA)∶M(HPA)为7∶3时,阻CaCO3垢率最高为80.9%。为探究此聚合物是否有更高的阻垢性能,应用多元回归分析对正交实验结果进行分析及验证,聚合物阻CaCO3垢效率y与各影响因素x之间基本满足y=-146.825+16.25x2,最佳聚合条件为X2=14.5,y为90.20%。     

Effect of elevated tropospheric ozone on methane and nitrous oxide emission from rice soil in north India

Physiological changes in crop plants in response to the elevated tropospheric ozone (O₃) may alter N and C cycles in soil. This may also affect the atmosphere-biosphere exchange of radiatively important greenhouse gases (GHGs), e.g. methane (CH₄) and nitrous oxide (N₂O) from soil. A study was carried out during July to November of 2007 and 2008 in the experimental farm of Indian Agricultural Research Institute, New Delhi to assess the effects of elevated tropospheric ozone on methane and nitrous oxide emissions from rice (Oryza sativa L.) soil. Rice crop was grown in open top chambers (OTC) under elevated ozone (EO), non-filtered air (NF), charcoal filtered air (CF) and ambient air (AA). Seasonal mean concentrations of O₃ were 4.3 ± 0.9, 26.2 ± 1.9, 59.1 ± 4.2 and 27.5 ± 2.3 ppb during year 2007 and 5.9 ± 1.1, 37.2 ± 2.5, 69.7 ± 3.9 and 39.2 ± 1.8 ppb during year 2008 for treatments CF, NF, EO and AA, respectively. Cumulative seasonal CH₄ emission reduced by 29.7% and 40.4% under the elevated ozone (EO) compared to the non-filtered air (NF), whereas the emission increased by 21.5% and 16.7% in the charcoal filtered air (CF) in 2007 and 2008, respectively. Cumulative seasonal emission of N₂O ranged from 47.8 mg m⁻² in elevated ozone to 54.6 mg m⁻² in charcoal filtered air in 2007 and from 46.4 to 62.1 mg m⁻² in 2008. Elevated ozone reduced grain yield by 11.3% and 12.4% in 2007 and 2008, respectively. Global warming potential (GWP) per unit of rice yield was the least under elevated ozone levels. Dissolved organic C content of soil was lowest under the elevated ozone treatment. Decrease in availability of substrate i.e., dissolved organic C under elevated ozone resulted in a decline in GHG emissions. Filtration of ozone from ambient air increased grain yield and growth parameters of rice and emission of GHGs.     

NaCl溶液pH值对5083铝合金腐蚀的影响研究

采用电化学试验方法,结合金相组织观察、SEM、腐蚀形貌观察等,研究了在不同pH值时3％(质量分数)NaCl溶液中5083铝合金的点蚀电位、自腐蚀电位及腐蚀质量损失.研究结果表明,5083铝合金点蚀电位基本接近,自腐蚀电位存在差异,而且在强酸、强碱溶液中会发生全面均匀的腐蚀溶解;在弱酸、弱碱或偏中性溶液中由于在夹杂物及基...     

Work hardening and mechanical properties of severely deformed AA3003 by constrained groove pressing

A severe plastic straining method, called constrained groove pressing, is used to improve the microstructure and mechanical properties of non-hardenable 3003 Al-Mn alloy. Williamson-Hall method is utilized to measure the grain size from X-ray diffraction patterns of deformed samples. The results show that ultra-fine grained 3003 alloy having grain size of 580 nm can be successfully produced by constrained groove pressing at room temperature. Mechanical properties of sheets, examined by tensile test, are approximately exhibited 170% improvement in comparison with those of annealed sample. Also, comparing the achieved results with those of aluminum 1100 alloy confirms the rapid rate of grain refinement and mechanical properties improvement in 3003 alloy. This is attributed to the presence of fine dispersoids of Al₆Mn in microstructure of the alloy. Tensile tests demonstrate that the work hardening rate of constrained groove pressed sheet is increased in comparison with that of annealed samples. Investigating of the work hardening by a model reveals why improvement stops after third pass and also work hardening rate diagrams show that only one stage of work hardening is detectable for the sheet after three passes of constrained groove pressing, while in lower pass numbers, more work hardening stages can be observed.     

船用铝合金点蚀及阴极保护研究

通过极化试验、循环伏安试验及外加恒电位阴极保护下的腐蚀失重试验,并结合腐蚀形貌观察,研究了5083铝合金在人造海水中的极化及腐蚀特性,并探讨了其阴极保护电位范围。研究表明,50834g@金在人造海水中浸泡一段时间后,由于表面生成钝化膜而提高了点蚀电位;但若阴极保护电位过负,表面会发生析氢反应,且表面局部因碱性过强而造成溶解,因此其合理的阴极保护电位范围为-0．9～-1.10V。     

5083铝合金电化学性能影响因素研究

采用动电位扫描及循环伏安试验方法,研究了工作电极表面状态、Cl浓度、pH值等因素对5083铝合金在质量分数为3．5％的NaCl溶液中电化学性能的影响。研究结果表明,试样表面进行抛光后,点蚀电位变正,点蚀保护电位正移。随着Cl-浓度的降低,点蚀电位磊明显正移;当Cl-浓度超过1％（质量分数）后,Cl-浓度对鼠的影响则不明显。溶液的pH值及其它阴离子的添加均会对5083铝合金点蚀电位及保护电位产生影响。     

水稻杂交后代表观直链淀粉质量分数与蜡质基因(CT)n微卫星多态性的相关性

以来自２ 个水稻杂交组合的后代遗传群体为材料,研究了蜡质基因（ Ｗｘ） 微卫星标记（ＣＴ）ｎ 多态性与稻米表观直链淀粉质量分数（ ｗ（ＡＡ）） 之间的相关性． 第１ 个群体是浙农８０１０ 与嘉育２９３ 的杂交Ｆ６ 代育种品系,双亲均为籼稻,ｗ（ＡＡ） 分别为８ ．７％ 和２５．６ ％ ,Ｗｘ 基因型为分别为（ＣＴ）１８（ＣＴ）１８ 和（ＣＴ）１１（ＣＴ）１１ ．另一群体为ＣＭ１０１ 与ＩＧＲＡ４０９ 杂交Ｆ５ 家系,亲本ＣＭ１０１ 为一个粳型糯稻,Ｗｘ 基因型为（ＣＴ）１８（ＣＴ）１８ ;ＩＧＲＡ４０９ 为籼稻,ｗ（ＡＡ） ＝ ２７．５％ ,Ｗｘ 基因型为（ＣＴ）１１（ＣＴ）１１ ．结果发现,在２ 个杂交组合的后代群体中,高ｗ（ＡＡ） 材料Ｗｘ 基因型均为（ＣＴ）１１（ＣＴ）１１ ,低ｗ（ＡＡ） 及糯稻的均为（ＣＴ）１８（ＣＴ）１８ ,中等ｗ（ＡＡ） 材料的则为（ＣＴ）１８（ＣＴ）１１ 的杂合体．统计分析表明,Ｗｘ 基因型与ｗ（ＡＡ）之间存在显著的相关性,在浙农８０１０×嘉育２９３ 和ＣＭ１０１ ×ＩＧＲＡ４０９ 两个群体中相关系数分别达０ ．９５０９ 和０．９７０４．