铁在寒地早粳花药培养中的效应研究

摘要：铁是水稻花培培养基的重要成分。通过对7份寒地早粳组合F1（或品系）花药在不同Fe2+含量培养基上离体培养,发现培养基中的Fe2+的含量对诱导率、绿苗分化率影响较大。结果表明在N6培养基中将Fe2+提高到32-40mg/kg诱导率最大,高于N6培养基（Fe2+含量为5.6mg/kg）1.4倍以上。在此以内随着Fe2+含量的增加诱导率增加,大于此含量诱导率降低,呈单峰曲线分布。分化培养基中Fe2+含量增加到40mg/kg分化率显著降低。但在32-40mg/kgFe2+培养基上诱导出的愈伤组织在MS培养基上的绿苗分化率差异明显,71.4%材料可使绿苗生产率提高到9.2%左右。因此适当提高诱导培养基中Fe2+含量可提高寒地早粳的花培效率。     

接种丛枝菌根真菌对不同类型盐碱胁迫下向日葵生长及盐离子积累的影响

目的 探讨接种丛枝菌根(Arbuscular mycorrhizal, AM)真菌对不同类型盐碱胁迫下向日葵生长和盐分离子积累的影响,为不同类型盐碱地的利用与生物修复提供基础数据和技术支持。方法 采用温室盆栽的方式,研究接种AM真菌摩西斗管囊霉Funneliformis mosseae处理对不同类型盐碱胁迫(CK、NaCl、NaCl+Na₂SO₄、NaCl+NaHCO₃)下向日葵Helianthus annuus菌根侵染率、生物量、营养元素吸收、C∶N∶P化学计量比、Na⁺吸收积累、光合作用以及细胞膜透性的影响。结果 3种类型盐碱胁迫使得接种AM真菌F. mosseae向日葵菌根侵染率降低29.53%~47.31%。3种类型盐碱胁迫处理均在一定程度上抑制了向日葵的生长,抑制效果的顺序为NaCl+Na₂SO₄>NaCl+NaHCO₃>NaCl。接种AM真菌使得NaCl、NaCl+Na₂SO₄、NaCl+NaHCO₃盐碱胁迫下向日葵的总干质量分别增加了19.58%、42.15%和60.35%。接种AM真菌使CK、NaCl和NaCl+NaHCO₃处理茎叶P质量分数分别增加了82.50%、71.11%和74.47%,使CK和NaCl+NaHCO₃处理根系P质量分数分别增加了61.54%和88.37%;使CK和NaCl+NaHCO₃处理茎叶和根系C∶P和N∶P显著降低,使NaCl处理茎叶C∶P和N∶P显著降低。接种AM真菌使NaCl+NaHCO₃处理茎叶和根系Na⁺积累量增加了33.76%和82.25%,使NaCl+Na₂SO₄处理根系Na⁺积累量增加了74.20%。接种AM真菌使NaCl和NaCl+NaHCO₃处理叶片蒸腾速率(Tr)增加了11.67%和10.12%,使NaCl+NaHCO₃处理叶片气孔导度(Gs)增加了20.00%,使3种类型盐碱胁迫处理下叶片的净光合速率(Pn)均呈增加的趋势;使NaCl+NaHCO₃处理叶片细胞膜透性降低了51.49%。结论 AM真菌可在一定程度上缓解盐碱胁迫处理对向日葵生长的毒害作用,但接种效应在不同类型盐碱胁迫间存在显著差异。     

Supplemental iron and phosphorus increase dietary inclusion of cottonseed and soybean meal in olive flounder (Paralichthys olivaceus)

A long‐term feeding experiment was conducted to investigate the use of cottonseed and soybean meal (CS) with iron and phosphorus supplements in diets for olive flounder (Paralichthys olivaceus). Olive flounder with an initial average size of 28.5 ± 0.35 g (mean ± SD) were divided into 15 groups (three tanks per dietary treatment) and fed 480 g kg^?1 crude protein diets in which each of five isonitrogenous diets was formulated to contain different levels of cottonseed/soybean meal (1 : 1) to replace fish meal (FM) with iron and phosphorus supplementations. The five experimental diets were as follows: diet 1 (control), 0%CS; diet 2, 20%CS; diet 3, 30%CS; diet 4, 30%CS + Fe&P; and diet 5, 40%CS + Fe&P. After 26 weeks of feeding trial, no significant differences were observed in weight gain, feed utilization and survival among all the treatments. The total gossypol accumulation in liver of fish fed diets supplemented with iron was significantly lower than that of fish fed diets without supplementation of iron. The results indicate that the addition of iron in diets could prevent the absorption of free gossypol. The findings in this study suggest that dietary supplements of iron and phosphorus could increase the inclusion of cottonseed and soybean meal for FM replacement in diets for marine fish species.     

Temporal trends in bromide release following rewetting of a naturally drained gully mire

Abstract. Recently, there has been interest in the occurrence of bromide (Br^-) in natural waters since it has been demonstrated that Br^-, in association with humic substances in raw waters, is readily incorporated into haloacetic acids in the form of organically bound bromine (Br) during water chlorination. We report results of the effects of experimentally rewetting a naturally drained gully mire on the hydrochemistry of Br^-, iron (Fe) and dissolved organic carbon (DOC) in the peat water. Results obtained over a three year period showed that rewetting substantially increased the concentrations of these solutes in the pore water, with peak values of 1 mg dm^-3 (Br^-), > 60 mg dm^-3 (Fe) and > 300 mg dm^-3 (DOC) detected in some samples after rewetting, compared with typical values < 0.05 mg dm^-3 (Br^-), < 1 mg dm^-3 (Fe) and < 15 mg dm^-3 (DOC) under the drained conditions. Bromide, Fe and DOC release were highly seasonal, with the largest concentrations observed in late-summer to autumn. However, whereas seasonal peak concentrations of Fe and DOC have since remained at these higher levels, seasonal peak concentrations of Br^- were progressively attenuated over time, suggesting the latter phenomenon is a flush effect, with no longer-term consequences for water quality.     

过渡金属氧化物对木粉/PVC复合材料燃烧性能的影响

用锥形量热仪(CONE)和热重分析法(TGA)研究金属氧化物CuO、La2O<,3>和TiO2对木粉/PVC复合材料(WF-PVC)燃烧性能的影响.结果表明,这3种过渡金属氧化物的加入对WF-PVC均有阻燃作用.其中,CuO使热释放速率(HRR)和总热释放量(THR)降低较多,阻燃效果明显;加入金属氧化物使WF-PVC的烟释放速率(SPR)和总烟释放量(TSP)都有所降低,其中,CuO在有焰燃烧阶段烟释放量最低,抑烟效果最好.这3种氧化物都能增加成炭量.结合热重分析的结果,3种金属氧化物对WF-PVC的热降解影响是不同的.PVC和木粉之间存在相互作用,PVC显著促进了木粉的热降解,木粉的加入推迟了PVC的降解,明显提高了PVC体系的成炭量;WF-PVC的热降解行为,具有更多的PVC降解的特征.     

等温淬火球墨铸铁的热处理及应用

探索了等温淬火球墨铸铁的生产工艺,分析了原料化学成分的选择,及铸造工艺中的熔炼、球化和孕育处理、浇注温度对制取球墨铸铁的影响;在获得基体组织合理的球墨铸铁的前提下,重点分析了热处理工艺中的奥氏体化温度、等温淬火温度和时间对ADI组织及性能的影响,通过实验及分析,确定了制取理想ADI的最佳热处理工艺。     

复合镀铁技术与工程车辆发动机气缸的修复

通过介绍复合镀铁技术的特点,以工程车辆发动机气缸的实际工况为基础,进行快速模拟磨损对比试验,研究复合镀铁材料的磨损规律,并绘制了负荷-速度-磨损量三维曲面图。本文对复合镀铁材料的耐磨性进行较全面的评价,初步探讨了复合镀铁用于强化工程车辆发动机气缸的可行性。     

模拟消化体系中乳及发酵乳对铁化学状态及透析率的影晌

本文通过体外消化来模拟消化系统以研究乳及发酵乳对FeCl3中铁的化学状态及透析率的影响，结果表明，在消化过程中乳及发醇乳可促进铁的溶解、以及Fe3 的还原和铁的透析，这一作用与样品的pH元失，认为是消化过程中产生的氨基酸和肽起了作用。研究还发现，原乳先加铁盐再送行发酵所产生的作用要较发醇后再加铁盐的作用大，认为发醇乳对铁化学状态及透析率的影响具有时间效应。此外，有乳存在的各试验组其Fe3 透析率较可溶性铁的透析率与对照组差异更大。     

电麻醉对西伯利亚鲟幼鱼行为特性与血清离子浓度的影响

研究了不同强度电麻醉对西伯利亚鲟幼鱼行为特性与血清离子浓度的影响。西伯利亚鲟电麻醉阶段包括部分失去平衡期、完全失去平衡期、完全麻醉期和鳃动停止期等4个时期。电麻醉时西伯利亚鲟呈现趋阳性;随着电压升高,到达各麻醉阶段时间与恢复时间逐渐缩短。西伯利亚鲟到达完全麻醉期时间在15 V、20 V、25 V、35 V组间均有显著差异,在30 V与35 V时分别仅为97.0 s和68.8 s,而恢复时间为0 s。各试验组西伯利亚鲟在电麻醉时鳃动频率均增加,而恢复阶段均降低。电麻醉对西伯利亚鲟摄食与活动状态均无显著影响。随着电压升高,钾离子与镁离子浓度先下降后上升,钙离子则先上升后下降。钠离子与氯离子浓度变化较大,均是15 V组时浓度最低,20 V时浓度最高。磷离子浓度呈现增高趋势。pH值在麻醉后降低,对照组与其余各组均有显著性差异。因此西伯利亚鲟幼鱼适宜电麻醉强度为25~30 V,电麻醉是种较好的麻醉方法,具有广泛的应用前景。