挡烟垂壁作用下狭长通道内烟气输运特征研究

为揭示挡烟垂壁对狭长通道火灾烟气特征及温度分布的影响,运用火灾动力学软件FDS,研究了狭长通道内不同高度挡烟垂壁下火灾烟流运动行为,重点探讨了密度跳跃过程及近火源区烟气特征参数变化。结果表明:挡烟垂壁增加了密度跳跃中翻滚区的长度,缩小了卷吸空气范围,造成烟气质量流率相应减少;挡烟垂壁对烟气垂直速度分布的影响主要作用在挡烟区,且与垂壁高度有关;垂高大于0.3 m,受挡烟垂壁高度影响,在垂直高度1.5~2 m位置出现一定速度的烟气逆流,速度分布曲线呈现与无挡烟垂壁不同的凹陷区,非挡烟区烟气垂直速度服从高斯分布;与无挡烟垂壁相比,挡烟垂壁上游顶棚附近温度普遍增高,下游温度衰减速率随挡烟垂壁高度的增加而加快。     

Activity and characteristics of “Oxygen-enriched” highly reactive absorbent for simultaneous flue gas desulfurization and denitrification

An “Oxygen-enriched” highly reactive absorbent was prepared by mixing fly ash, lime and a small quantity of KMnO₄ for simultaneous desulfurization and denitrification. Removal of SO₂ and NO simultaneously was carried out using this absorbent in a flue gas circulating fluidized bed (CFB). The highest simultaneous removal efficiency, 94.5% of SO₂ and 64.2% of NO, was achieved under the optimal experiment conditions. Scanning Electron Microscope (SEM) and Accessory X-ray Energy Spectrometer (EDX) were used to observe the surface characteristics of fly ash, lime, “Oxygen-enriched” highly reactive absorbent and the spent absorbent. An ion chromatograph (IC) and chemical analysis methods were used to determine the contents of sulfate, sulfite, nitrate and nitrite in the spent absorbents, the results showed that sulfate and nitrite were the main products for desulfurization and denitrification respectively. The mechanism of removing SO₂ and NO simultaneously was proposed based on the analysis results of SEM, EDX, IC and the chemical analysis methods.     

二氧化硫胁迫对不同抗性玉米幼苗活性氧代谢的影响

采用60mg·m-3SO2气体处理玉米（Zea Mays.L）幼苗,通过组织化学染色和定量测定,分析了高抗自交系齐139和敏感自交系昌7-2在活性氧代谢上的差异。结果表明：SO2胁迫处理3h后,高抗系齐139幼苗叶片积累了较高的O2-和H2O2,12h后被迅速清除而趋于平衡;而高感系昌7-2叶片在胁迫早期产生的O2-和H2O2较少,后期有大量的O2-和H2O2积累,导致细胞损伤。抗氧化酶SOD和CAT在抗性系中显著升高,而敏感系中增幅不显著。这一研究表明不同抗性系中活性氧代谢的差异可能与其对SO2的抗性密切相关。     

零价铁还原降解活性染料

在分别通氮气,不通氮气和曝气的情况下,在水溶液中用零价铁还原降解活性染料。实验发现：在不同的氛围中,活性染料的降解程度不同,其降解程度为：暴气〉不通氮气〉通氮气。在不同通氮 和曝气的条件下,活性染料的降解过程中有黄色絮状沉淀生成,经红外光谱鉴定为三聚氯氰的取代产物。     

复极性固定床电解反应器对活性染料的降解

本文用复极性固定床电解反应器对１６种活性染料的脱色降解进行了试验研究。结果表明：染料脱色率在９９．６％以上,出水上清液ＣＯＤ去除率绝大部分在９０％以上,对活性翠蓝ＫＮ－Ｇ和活性深蓝ＫＭ－ＧＲ的铜去除率分别为９７．０％和９９．７％。     

脱色菌腐败希瓦氏菌的分离及其脱色性能研究

从印染废水处理装置中分离到一株高效脱色菌,经鉴定为腐败希瓦氏菌(Shewanella putrefaciens),这是该菌具有高效脱色性能的首次报道。在实验条件下,对该菌的脱色能力进行比较研究,它在合适条件下能有效地去除生产上常用的多种染料,在6h内对活性艳红染料的去除率可达99％～100％。实验中对充氧、温度以及共代谢碳源等因子对该苗的脱色能力的影响进行了研究,为在生产实际中的应用提供了依据。     

Eco‐hydraulic Evaluation of a Whitewater Park as a Fish Passage Barrier

Whitewater parks (WWPs) typically consist of instream structures that enhance recreational boating by constricting flow into a steep chute that generates a hydraulic jump in a downstream pool. Concerns have been raised that high velocities resulting from WWPs may be inhibiting fish movement during critical life stages. We evaluated the effects of WWPs on upstream fish passage by concurrently monitoring fish movement and hydraulic conditions at three WWP structures and three adjacent natural control (CR) sites in a wadeable river in northern Colorado. Fish movement was tracked with a network of Passive Integrated Transponder antennas over a 14‐month period. Individual fishes (n = 1,639), including brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss), were tagged and released within WWP and CR sites. Detailed hydraulic conditions occurring during the study period were evaluated with a fully 3D model. Results reveal the WWPs monitored in this study are not a complete barrier to upstream salmonid movement, but differences in passage efficiency from release location range from 29 to 44% in WWP sites and 37 to 63% for CR sites and the suppression of movement is related to body length. Small numbers of monitored nonsalmonids were inadequate to directly observe effects on their movement; however, it is highly probable that movement of smaller native fishes is also suppressed. Hydraulic modeling helps in the design of WWP structures that protect fish passage.     

控制酸性矿山废水的污泥屏障压缩特性

污泥屏障通过物理拦截以及化学作用可以有效控制重金属离子迁移,采用污泥屏障处理酸性矿山废水(AMD)已被证明具有可行性.作为尾矿渣处置场屏障的主体材料,研究污泥压缩特性很有必要.实验结果表明,对于含水率相同的压实污泥试样,孔隙比随干密度增大而减小,最终趋于1;干密度相同的试样,最优含水率的孔隙比随应力增大减小最快.试样压缩系数随干密度增大而减小,随含水率增大先增大后减小,最优含水率的压缩系数为0.8 MPa-1.AMD溶液作孔隙液能提高试样压缩系数.通过对比分析有机质土的压缩特性,为以后的深化研究提供相关参数支持.     

复合混凝剂的制备及活性染料的去除

以马铃薯淀粉、丙烯酰胺（AM）和二甲基二烯丙基氯化铵（DADMAC）为原料进行接枝反应,将接枝产物（TSI）与聚合氯化铝铁（PAFC）复配,制得新型复合混凝剂PAFC-TS1。优化了复合混凝剂制备的工艺条件。研究结果表明,复合混凝剂PAFC-TS1的优选制备条件为：OH^-浓度与铝铁总浓度的比（r）为0.5,铝铁总浓度与TS1的质量浓度比（R_m）为0.5 mol/g,铝铁摩尔比9∶1。在此条件下处理质量浓度为100 mg/L的活性染料废水,当混凝剂投加量为24 mL/L时,染料去除率可达97%以上。相同条件下,使用PAFC-TS1比单独使用PAFC或PAFC-PAM的染料去除率更高。     

Characterisation of early responses to cadmium in roots of Salix matsudana Koidz

This study deals with the characterisation of early responses of roots of Salix matsudana in respect to oxidative stress, subcellular distribution, and chemical forms when exposed to 50 μmol/L Cd. Within 12 h, the root length is reduced and the contents of O₂^??, H₂O₂, and malondialdehyde are increased by 49%, 43%, and 35%. Cd is mainly retained in the cell walls; small amounts are distributed into other cell organelles. The largest proportion of Cd is found in the NaCl extractable, pectate-, and protein-integrated fraction.