模拟酸雨对水稻生长与水稻土养分的影响

采用温室盆栽水稻喷淋模拟酸雨实验,研究不同pH值(2.5,3.5,4.5,5.6)的酸雨对水稻生长和水稻土养分的影响。结果表明:在酸雨的影响下,除喷淋pH 4.5酸雨外,其余酸雨处理的土壤有机质均下降了9.1%～16.7%;不同浓度的酸雨对土壤碱解氮的影响不大,但速效钾在喷淋酸雨后相对基础土样下降了33.9%左右;土壤速效磷含量相对基础土样提高了21.3%～40.5%;土壤有效硫的含量随着酸雨pH的降低而升高;喷淋酸雨后土壤中的交换性钙、镁相对基础土样分别上升了27.6%～36.3%和3%～21%。酸雨对水稻茎叶氮的吸收影响不大,但水稻稻粒中全氮的含量会随着酸雨pH的降低而升高;酸雨不利于水稻茎叶对养分磷的吸收,但pH 2.5的酸雨会促进稻粒对磷的吸收;酸雨有利于水稻茎叶对养分钾的吸收,但不利于稻粒对养分钾的吸收;水稻茎叶和稻粒中全硫的含量会随着酸雨pH的降低而升高。水稻在pH 2.5的酸雨影响下显著减产,喷淋了pH 3.5酸雨的水稻其千粒重、结实率和实粒数都是最高的,表明pH 3.5的酸雨对水稻产量的提高有一定的刺激作用。     

酸性茜素兰褪色光度法测定食盐中碘含量

[目的]介绍加碘盐中碘含量测定的新方法。[方法]根据碘酸银氧化酸性茜素兰使其褪色,且褪色前后溶液的吸光度差ΔA与碘含量成正比的原理,在最佳褪色条件下测定食盐样品A、B中的碘含量 在样品液中加入碘酸钾标准溶液,测定碘的回收率。[结果]酸性茜素兰在517 nm处有最大吸光度,其最佳褪色条件为温度40℃,时间10 min,0.5 mol/L溴化钾用量4.00 ml,硫酸用量2.00 ml,0.50 g/L酸性茜素兰用量5.0 ml 10.029 0 g样品A和10.030 2 g样品B中碘的含量分别为26.52和32.83 mg 样品液A、B中碘的加样回收率分别为95.0%和104.2%。[结论]酸性茜素兰褪色光度法测定食盐中的碘含量具有稳定性好,准确度、灵敏度高,操作简便等优点,具有推广应用价值。     

不同植物中绿原酸的提取

综述了近年来国内从金银花、杜仲、向日葵、红薯中提取绿原酸的工艺。     

改性甘蔗渣吸附水溶液中酸性染料的研究

[目的]寻找新的、低值的、具有高效染料吸附能力的生物材料来加强染料废水污染的治理工作。[方法]以磷酸改性处理后的甘蔗渣作为生物吸附剂,对水溶液中的酸性橙和酸性金黄染料进行吸附研究,探讨了溶液的pH值、染料初始浓度、吸附温度、改性甘蔗渣用量、吸附时间等因素对吸附的影响,并将其同没有经过改性处理的普通甘蔗渣进行比较。[结果]在染料浓度50 mg/L、吸附剂投量2.0 g/100 m l、pH值2、吸附温度35℃、吸附时间180 m in的情况下,改性甘蔗渣对酸性金黄和酸性橙的吸附率分别达到97.8%和96.4%,相对于没有改性的普通甘蔗渣,其吸附率分别提高了63.3%和65.7%。[结论]通过酸改性的甘蔗渣是一种良好的酸性染料生物吸附剂。     

重庆市3种不同类型监测点降水成分比较及趋势分析

对重庆市3种不同类型监测点的降水进行连续7年的监测。结果表明,四面山降水污染最轻,酸雨频率最高;观音桥点降水污染最重,酸雨频率最低。     

“碳铵-杀虫双”新型诱杀剂对黄脊竹蝗的防治意义

黄脊竹蝗是我国仅次于松毛虫的森林大害虫,一些传统的防治方法的综合防治效果并不理想。笔者在多年的森保工作中探索出一种新型的黄脊竹蝗诱杀剂——“碳铵-杀虫双”,其防治效果优于传统的防治方法。     

铅离子对栉孔扇贝幼贝几种免疫因子的影响

测定了栉孔扇贝幼贝在不同浓度Pb2+胁迫下体内酸性磷酸酶(ACP)和碱性磷酸酶(AKP)的活力变化以及过氧化氢(H2O2)含量的变化情况.结果表明,当Pb2+浓度为0.01 mg·L-1时栉孔扇贝幼贝体内ACP和AKP活力明显高于对照组,且差异极显著(P<0.01),随Pb2+浓度的增加,酶活力呈下降趋势,在0.05Mg·L-1时酶活力低于对照组;栉孔扇贝幼贝H2O2含量的变化在0.01 mg·L-1和0.02 mg·L-1低浓度Pb2+影响下呈缓慢升高的趋势,但总体变化不明显,而当Pb2+浓度达到0.05mg·L-1H2O2含量明显高于对照组,且差异极显著(P<0.01),随Pb2+浓度的增加,H2O2含量缓慢增加.说明Pb2+能破坏幼贝机体的免疫防御功能,在海洋污染中,Pb2+胁迫是使栉孔扇贝幼苗抗痛力减弱、种质退化、并引起大量死亡的一个较为重要的因素.     

6%抗坏血酸水剂对3种水果的增产效果

为探讨6%抗坏血酸水剂在杨梅、樱桃、艳红桃3种水果上的应用效果,进行了田间试验和生产示范.结果表明:VC及可溶性固型物处理区较对照区提高16%～45%,酸度下降10%以上,增产10%～30%,效果较好.     

稀土元素对酸雨胁迫小麦活性氧清除系统响应的作用

盆栽条件下,就酸雨胁迫下小麦活性氧清除系统的响应及稀土元素作用进行了研究。结果表明：酸雨导致小麦活性氧酶促系统的SOD, CAT, POD酶活性总体水平发生变化。CAT, SOD活性减弱,POD活性增加,致使体内活性氧清除能力减弱,稀土元素的施用增加了CAT, SOD活性水平,削弱了由于酸雨胁迫所导致的POD活性的增加,从而增强了清     

Leaching losses of sulphur from different forms of sulphur fertilizers: a field lysimeter study

Abstract. Inputs and outputs of sulphur (S) were quantified over a three year period using field lysimeters containing undisturbed 60 cm deep soil monoliths of a sandy loam. There were four treatments, including a control (no S) and three forms of sulphur fertilizers: ammonium sulphate (AS); micronized elemental sulphur (MS⁰); and bentonite clay and elemental sulphur mixture (BS⁰). Sulphur was applied at the beginning of the experiment in autumn at 50 kg ha^–1. Atmospheric deposition varied between 6.7 and 7.8 kg S ha^–1 yr^–1. Leaching losses of S ranged from 35 kg ha^–1 in the control to 83 kg ha^–1 in the AS treatment over three years, with dissolved organic S accounting for 6–10% of the S leached. In the first year, 7, 26 and 72% of the applied S was lost to drainage water in the BS⁰, MS⁰ and AS treatments, respectively, and the percentages increased to 33, 75 and 96% by the end of year 3. No significant differences in sulphur uptake by herbage were found in any of the harvests except a significant increase in the BS⁰ treatment in the second cut of the second year. Over three years, total S outputs exceeded total S inputs in all treatments, with the control and the AS treatments showing a larger S deficit (34–35 kg ha^–1) than the MS⁰ (23 kg ha^–1) and BS⁰ (7 kg ha^–1) treatments. The deficits indicate a depletion of soil S, probably through net mineralization of organic S. The results confirm that sulphate was highly mobile and prone to leaching under the experimental conditions, whereas the slow release characteristics of elemental S, particularly BS⁰, led to smaller leaching losses and larger residual values.