2024-T62铝合金薄板长裂纹腐蚀扩展研究

通过变化应力比、预腐蚀时间、试验环境,开展2024-T62铝合金薄板长裂纹扩展试验。对试验结果进行处理与分析,给出腐蚀环境下2024-T62铝合金裂纹扩展Paris公式或Walker公式的材料常数,确定上述变化因素对2024-T62铝合金薄板长裂纹扩展速率的影响规律。     

混凝—热固化联合空气吹脱法处理高浓度水性油墨废水

采用混凝—热固化联合空气吹脱法处理高浓度水性油墨废水。混凝—热固化法处理高浓度水性油墨废水的优化工艺条件为混凝剂NS-1投加量7.36 g/L,热固化温度75 ℃,热固化时间30 min,在此条件下COD去除率达91.00%,色度去除率达99.00%。空气吹脱法处理混凝—热固化出水,初始ρ（氨氮）对氨氮去除率影响较小;气液比增大、废水pH升高、吹脱次数增加、废水温度升高均能提高氨氮去除率。在废水初始ρ（氨氮）为1 406.25 mg/L、气液比为2 667、废水pH为11.50、废水温度为25 ℃、连续吹脱4次的条件下,氨氮去除率达95.34%。     

The convective hot air drying of Lactuca sativa slices

The storage of fresh agricultural products is not easy because of its high moisture. Dehydration is an efficient preservation method. The investigation of drying modeling and transfer characteristics are important for selecting operating conditions and equipment design. The drying behavior of Lactuca sativa slices, with the thickness of 2 mm, was investigated at 60.0–80.0°C and 0.60–1.04 m sec^?1 velocity in a convective hot air drier. The mass transfer during the drying process was described using six thin drying models. The convective heat transfer coefficient α and mass transfer coefficient k_H were finally calculated. The results showed that the drying process could be separated into three stages including accelerating rate, constant rate, and falling rate period, which was influenced by hot air temperature and velocity, and the Modi?ed Page model agreed well with the experimental data. When the operating temperature was increased from 60.0°C to 80.0°C, α was found increased from 88.07 to 107.93 W·m^?2·K^?1, and k_H increased from 46.32 × 10^–3 to 68.04 × 10^–3 kg·m^?2·sec^?1·ΔH^?1. With the increase of air velocity from 0.60 to 1.04 m·sec^?1, α was increased from 78.85 to 101.35 W·m^?2·K^?1, and k_H was enhanced from 51.78 × 10^–3 to 65.85 × 10^–3 kg·m^?2·sec^?1·ΔH^?1.     

Experimental study on MSW gasification and melting technology

In order to develop municipal solid waste (MSW) gasification and melting technology, two preliminary experiments and a principle integrated experiment were fulfilled respectively. The gasification characteristics of MSW are studied at 500-750℃ when equivalence ratio (ER) was 0.2-0.5 using a fluidized-bed gasifier. When temperature was 550-700℃ and ER was 0.2-0.4, low heat value (LHV) of syngas reaches 4000-12000 kJ/Nm3. The melting characteristics of fly ash were investigated at 1100-1460℃ using a fixed-bed furnace. It was proved that over 99.9% of dioxins could be decomposed and most heavy-metals could be solidified when temperature was 1100-1300℃. The principle integrated experiment was carried out in a fluidized-bed gasification and swirl-melting system. MSW was gasified efficiently at 550-650℃, swirl-melting furnace maintains at 1200-1300℃ stably and over 95% of fly ash could be caught by the swirl-melting furnace. The results provided much practical experience and basic data to develop MSW gasification and melting technology.     

外源水杨酸对染铅小鼠抗氧化水平的调节

为了研究水杨酸对铅染毒小鼠体内抗氧化水平的调节,将不同浓度的水杨酸(0、0.1、0.5、1.0和1.5 mmol·L-1)附加到醋酸铅溶液中对小鼠隔日灌胃1个月,测定了肝和脑组织抗氧化酶活性以及脂质过氧化产物丙二醛(MDA)的含量,观察了核DNA的降解情况.结果显示,0.5mmol·L-1的水杨酸完全消除了铅(300 mg·kg-1)对小鼠超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的抑制,使MDA含量维持在对照水平,核DNA降解明显减轻.这些数据显示,外源水杨酸可通过调节铅胁迫下小鼠体内抗氧化酶的活性而保护肝和脑组织免受铅引发的氧化胁迫伤害.     

纳米二氧化钛胁迫对普生轮藻的毒性效应

纳米材料独特的理化性质使其得到了广泛的应用,但其可能带来的生物安全性问题也引起了广泛关注.实验研究了胁迫浓度梯度为0、0.01、0.10、1.0、10、100mg.L-1的纳米二氧化钛(nTiO2)悬浮液单一处理普生轮藻(CharavulgarisL.)的毒性效应,在胁迫24h、48h、72h、96h后分别测定其叶绿素a含量、脂质过氧化物丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和过氧化氢酶(CAT)活性.结果表明,随着胁迫浓度的增加和时间的延长,叶绿素a含量、SOD和CAT活性总体呈下降趋势,而MDA含量呈递增趋势,高浓度剂量组与对照组比较差异极显著,酶的活性降幅也较大,说明急性nTiO2暴露对普生轮藻具有毒性作用,且表现出剂量效应.     

酸雨对水稻不同生育期叶片叶绿体ATP酶的影响

酸雨对植物生长发育具有显著影响。然而,不同生长阶段植物对逆境胁迫的响应存在差异。以模拟酸雨胁迫水稻(Oryza sativa)(孕穗期、灌浆期),利用植物生理生化方法测定了水稻叶肉细胞叶绿体Mg2+-ATPase活性及其基因表达量、光合磷酸化活性、ATP含量、植株相对生长速率(RGR)和叶片净光合速率(Pn),研究酸雨胁迫下孕穗期、灌浆期水稻叶绿体ATP酶的变化及其对植物光合作用影响的机理。结果表明,p H=4.5酸雨使孕穗期水稻RGR、Pn、叶片ATP质量比和光合磷酸化活性均显著提高,灌浆期上述指标变化不明显;p H=3.5和p H=2.5酸雨使上述指标均下降,且随酸雨p H值降低,变幅增加。p H=4.5酸雨使孕穗期、灌浆期水稻ATP合酶基因表达量及Mg2+-ATPase活性升高;p H=3.5和p H=2.5的酸雨使孕穗期、灌浆期水稻ATP酶基因表达量减少,造成Mg2+-ATPase活性降低,且随酸雨p H值降低变幅增加。可以认为,酸雨通过影响ATP酶转录水平,改变Mg2+-ATPase活性、光合磷酸化活性和叶片ATP质量比,进而影响Pn,并最终影响植物生长发育。酸雨胁迫对孕穗期水稻生长发育及光合作用有低促高抑的剂量效应,而低强度酸雨对灌浆期水稻影响不明显。与灌浆期相比,孕穗期对酸雨胁迫较敏感,表明植物不同生长发育阶段对酸雨胁迫响应存在差异,此发现应成为评价酸雨影响植物的一个因素。     

冷应激对健康雏鸡某些内分泌活动的影响

以罗曼雄性雏鸡为试验对象,研究5d和10d龄健康雏鸡在低于正常饲养温度条件下,在一定时间内机体某些代谢激素的变化规律,结果表明：（1）5d龄雏鸡在两种低温情况下,血清三碘甲腺原氨酸（T3）变化显著,在冷应激最初几h内,T3先下降,至6h（15±1℃）和12h（10±1℃）又升高;血清四碘甲腺原氨酸（T4）变化不明显,在10±1℃情况下,在12h时显著降低;胰岛素（Ins）在两种低温情况下,均于2h时显著升高,而后呈波动性变化,（2）10d龄雏鸡在15℃±1℃条件下,T3在0．5～3h显著下降,至6h回升;T4在2h时显著升高（P＜0．05）;Ins在2h时升高（P＞0．05）,但3h时显著降低,而后又回升（3）血清皮质醇浓度均于冷应激后2h时有所升高,但差异不显著,而后呈波动性变化．     

酸胁迫对不同基因型玉米生长和钙镁养分吸收的影响

采用盆栽试验系统研究了不同耐酸特性的4个玉米自交系苗期、拔节期和散粉期的生长状况和钙、镁营养特性.结果表明,铝毒对玉米生长发育的影响贯穿于全生育期,但是影响强度随时间推移而减轻.在苗期,铝毒严重影响玉米对钙、镁营养的吸收,且对钙吸收的影响大于镁,不同基因型间存在明显差异.与酸敏感自交系相比,耐酸自交系苗期可保持较高的钙、镁浓度,地上部钙、镁耐酸指数显著高于酸敏感自交系.苗期之后,玉米钙、镁营养受酸胁迫的影响相对较小,除散粉期耐酸自交系功能叶中钙镁比表现较稳定外,其它钙镁营养特性没有表现出明显规律.     

喷雾分离脱硫过程中传热传质的数值研究

研究了SO2的吸收反应机理；重点采用数值模拟的方法分析讨论了各项参数对脱硫效率的影响规律。结果表明，液滴粒径、烟气流速、SO2入口浓度、液气比是影响脱硫效率的敏感参数。