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以‘早熟5号’大白菜(Beassica pekinensis L.)为试材,采用土施和叶面喷施三聚氰胺方式,观察并测定相关指标.结果表明,三聚氰胺在土壤中可发生缓慢降解,90 d后不同浓度处理(40、160和800 mg.kg-1)的土壤中三聚氰胺均有残留,分别残留21.1%、15.8%和43.6%.三聚氰胺处理浓度越高,大白菜吸收的量越大.土施试验,根中最高和最低含量分别为105.7和8.0 mg.kg-1,茎叶中为139.9和7.1 mg.kg-1,根吸收三聚氰胺后,可将其转运到地上部的茎叶中;叶面喷施试验,根中最高和最低含量分别为4.3和0.9 mg.kg-1,茎叶中为8.5和3.2 mg.kg-1.土施40 mg.kg-1三聚氰胺可增产9.8%,土施800mg.kg-1三聚氰胺减产15.9%,土施可增加叶绿素和可溶性糖含量,降低维生素C含量,叶面喷施三聚氰胺对大白菜的生长影响较小.三聚氰胺在土壤中的残留时间长,大白菜可通过根和茎叶吸收三聚氰胺,三聚氰胺可影响大白菜的生长状况. 相似文献
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再谈荒漠—绿洲对立统一观与干旱荒漠生态系统的持续发展 总被引:3,自引:0,他引:3
荒漠-绿洲是干旱气候区的两 类实体,它们具有不同演替阶段的植被特征,且绿洲寓于荒漠,异于荒漠并依一定条件互向对立面转化,绿洲化或荒漠化亦是其实例,这些现象受演替方向支配,引导两类生态系统同时沿演替轨道运转,使全局处于良性循环,对干旱荒漠生态系统实现持续发展将具极为重要作用。 相似文献
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荒漠、绿洲是干旱区客观存在的实体,各具有其本身的结构、功能与属性。研究表明:绿洲与荒漠既相互区别又相互联系,即绿洲寓于荒漠、异于荒漠,两者又依一定条件互向其对立面转化的对立统一体。在自然状态下,植被是其中相互联系的线索,生境的异质性是导致由量变引起质变的原因,水是导致相互转化的物质基础.透过生态系统演替,可以使定量的水源产生一定程度差异的生态效应,从而诱导干旱区生境稳定并实现持续发展目标。 相似文献
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Question : Whydoes the ILO co-sponsor the Forum with the SAWS? Answers: OSH is an important issue in China with rapid industrialization andeconomic restructuring. There are many major accidents happening in China. The Forum isone of the initiatives of the SAWS for improving the situation. As you know OSH is one ofILO''''s core mandates since its establishment in the ILO has been collaboratingwith China in this field for many years.…… 《现代职业安全》2002,(8):19
Question 1: Why does the ILO co-sponsor the Forum with the SAWS?
Answers: OSH is an important issue in China with rapid industrialization and economic restructuring. There are many major accidents happening in China. The Forum is one of the initiatives of the SAWS for improving the situation. As you know, OSH is one of ILO's core mandates since its establishment in 1919 and the ILO has been collaborating with China in this field for many years. 相似文献
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Somealdehydesandketonesaretoxicandcarcinogenic.Tothepolutionofaldehydesandketones,agreatatentionhasbeenpaidalovertheworld.The... 相似文献
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1IntroductionIthasbeenforalongtimeadisturbedproblemforhumanbeingstofindatradeofbetweeneconomicdevelopmentandenvironmentalpro... 相似文献
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厄尔尼诺与气候异常及对新疆的影响初探王玉辉,黄培 (新疆大学生物系乌鲁木齐830046)据近期有关报道,90年代第三次“厄尔尼诺”现象已在太平洋海域形成。笔者拟根据有关资料,论述这一现象的形成及其对世界、我国和新疆气候的影响,并讨论利用这一现象的可能?.. 相似文献