HTO在土壤-玉米系统中行为的动力学模型

TO在土壤 玉米系统中迁移、运输动态过程的研究表明 :引入土壤中的HTO不仅在系统各部分间转移和分配 ,而且迅速向系统外散逸 ;HTO中的氚以自由水氚和结合态氚形态存在于玉米植株和土壤中 ;植株中的自由水氚比活度于引入后 6h时达最大值 ,随后逐渐下降 ,而结合态氚呈缓慢增加 ;根中的HTO比活度开始时高于地上部 ,而后趋于平衡 ,表层土中两种形态氚基本呈逐渐下降趋势     

模拟池塘中锶-89的迁移和积累动力学

采用放射性同位素示踪技术研究了核污染关键核素之一——~(89)Sr在水生生态系中的动力学行为。当示踪剂~(89)Sr一次性引入水系后,即向系统内的动植物及底泥迁移,从而使系统各组分中~(89)Sr-Sr的量均随时间变化。结果表明:1.在试验期间,池水中~(89)Sr-Sr的含量随时间减少,6d后由原来的1.76 ppm降至1.01ppm,11d后已不到原来的一半,第35d时只及原始量的30％。2.池水中的~(89)Sr-Sr向系统各组分中的迁移速率和数量因组分的性质而异。比如底泥,1d后由原始的0增加到7.07 ppm,11d后趋向平衡,以后几乎不再增加;~(89)Sr-Sr在鱼和螺蛳体内的含量在试验期间均随时间增加,35d时分别由原始的0增加到18.73ppm和48.28ppm;在处理当天,金鱼藻中~(89)Sr-Sr虽增加较快,由原始的0增至6.68 ppm,但4h后却几乎不再增加。3.水生动植物对放射性锶都有一定的浓集作用,最大的浓集系数分别为:螺蛳94.7,鱼36.7,金鱼藻只有12.6。可见,贝壳类动物对水系中的放射性锶有较强的去污能力。     

水稻对放射性锶的吸收及撒洒硅藻土对其行为的影响

采用同位素示踪技术研究了水稻对89Sr的吸收及在水稻田中撒洒少量硅藻土对其吸收89Sr的影响。结果表明 :田表水中的89Sr将向水稻转移 ,通过吸附和吸收作用在水稻各部位中积累 ,其稻根中的89Sr比活度高于其余各部位 ;在本试验硅藻土撒洒量的范围内 ,未能明显降低水稻对89Sr的吸收和累积 ;89Sr在水稻中的纵向分布均与土层深度呈单项指数负相关。     

六种水培的苋科植物对~(134)Cs的吸收和积累(英文)

对营养液栽培 42d后的 6种苋科植物用不同13 4 Cs比活度处理 ,1周后收获并分析13 4 Cs比活度。结果表明 ,不同植物组织的烘干重和最大生长高度存在差异。不同植物和同种植物不同器官间13 4 Cs积累量表现为显著差异 ,但差异取决于初始加入到营养液中的13 4 Cs比活度。放射性自显影结果表明 ,各种植物叶片积累的13 4 Cs比根茎积累的多。籽粒苋 (AmaranthuscruentusL .)较其它植物生物量高、根系密度大、生长速率快 ,虽然籽粒苋中13 4 Cs比活度较低 ,但其茎叶器官从13 4 Cs水培液中剔除的13 4 Cs明显高得多 ,且表现出很高的13 4 Cs去除速率。研究还发现 ,6种植物叶部含钾量与13 4 Cs比活度之间存在较弱的线性相关性。     

~(60)Co在小麦-土壤系统中的消长动态

采用模拟污染物的核素示踪技术研究了60Co在小麦-土壤系统中的迁移、消长和分配动态,并建立了其行为规律的数学模型。结果表明:(1)60Co由表土进入系统后即在系统中发生迁移,小麦主要经根部吸收60Co,然后向其他各部位转移和分配。小麦植株中60Co比活度起初随时间迅速增高,达到某一最大值后开始下降。根中60Co比活度显著高于植株其他部位,小麦各部位中60Co比活度的大小顺序为:麦根>麦秸>麦壳>麦粒;(2)土壤中60Co主要滞留于表层6cm内,其比活度与距土表深度呈单项指数负相关;(3)60Co在小麦-土壤系统中比活度的动态变化规律由多项指数描述;(4)小麦对土壤中的60Co具有一定的富集能力。     

几种淡水动植物对14C-毒死蜱的吸收、分布和消长的研究

应用＾１４Ｃ－毒死蜱研究了５种淡水水一物对毒死蜱的吸收,分布,消长的规律。结果表明：５种生物在１４Ｃ－毒死蜱的水溶液中暴露４ｈ,均能迅速吸收＾１４Ｃ－毒死蜱,经过２４ｈ,５种生物对１４Ｃ－毒死蜱的ＣＦ从高至低的顺序为：食蚊鱼〉石螺〉扁卷螺〉浮萍〉西洋菜。当暴露２４或４８ｈ,３种试验动物对＾１４Ｃ－毒死啤吸收的量已达高峰。食蚊鱼,石螺和扁卷螺的ＣＦ分别为３７５,２４９．６９和３０。两种植物对１４Ｃ－     

施用白垩和膨润土对降低作物吸收放射性锶和铈的有效性

采用模拟污染物的同位素示踪技术研究了在土壤中施用白垩和在田表水中撒洒膨润土对降低作物 (尤其是作物的食用部分 )中89Sr和14 1Ce积累的效应。结果表明 :白垩能有效降低黑麦草、青菜对89Sr的吸收 ,当白垩施用量为 2 0g kg时 ,青菜对89Sr吸收降低率达 77 6% ,黑麦草也能降低 3 5 2 % ,土壤中白垩的引入量与黑麦草、青菜中89Sr的比活率呈显著性线性负相关 ;在田表水中的撒洒适量膨润土可以使田表水、稻壳和糙米中的14 1Ce比活度有所下降 ,从而减少稻谷对14 1Ce的积累 ,但未能改变稻根、稻草对14 1Ce的吸收和积累 ,14 1Ce在水稻土中的纵向分布均与土层深度呈单项指数负相关。     

鲮鱼对食物和水中110mAg的吸收和排泄

鲮鱼鱼苗摄食110mAg标记的人工饵料后排出十分快速 ,摄食 2 4h至第 7d后 ,鱼整体的放射性迅速降低约为 0h的 2 .62 % ,110mAg在鱼体内的分布很不均匀 ,其分布的比活度次序为肝>肠 >胆 >眼 >鳃 >剩余 >肌肉 ,肝脏、肠和胆最高 ,各占总体的 48.1 4% ,1 8.43.%和 1 5 .4%。110mAg从水中进入鱼体内的浓集系数 (CF)随积累时间的延长而上升 ,至第 1 3d上升为 2 0 8.6。排出速率相对于从食物途径的较为缓慢 ,第 1 5～ 2 8d后体内的放射性活度为 0h的 2 0 .1 %和1 6.7%。排出过程分为快相和慢相 ,0～ 2d内为快相 ,2d后为慢相 ,慢相的生物半排出期为2 2d。在积累和排泄期间110mAg在鱼体内的分布也主要积累在内脏 ,均约占总活度的 80 %。     

~(137)Cs不同污染水平在大亚湾、秦山、北京土壤植物系统的转移

采用我国大亚湾、秦山和北京土壤 ,模拟核裂变产物137Cs在 0Bq kg土、3 3×1 0 4 Bq kg土、3 3× 1 0 5Bq kg土、3 3× 1 0 6 Bq kg土污染水平时 ,研究土壤 -小麦系统的污染影响与137Cs核素的转移规律。结果表明 :在本试验条件下小麦生长发育处于正常状态 ,未发现对小麦有不良影响 ;小麦分别在 3个污染水平下从试验用的 3种土壤中吸收137Cs的趋势是一致的 ;小麦植株中137Cs的比活度随137Cs施入量相应以数量级增加 ,两者间呈十分显著的正相关 ;137Cs在土壤 -小麦系统中的转移系数随土壤的性质不同而变化 ,在同一污染水平下转移系数在n× 1 0 - 2 ～n× 1 0 0 范围变化 ;在同一种土壤中 ,随土壤污染水平的提高 ,转移系数亦有所提高 ,但变化范围不大 ,对北京土转移系数为 2 2× 1 0 - 2 ～ 5 4× 1 0 - 2 ,大亚湾土转移系数为 1 0 4～ 2 0 9,均在同一数量级内变化 ;对秦山土转移系数为 0 51～ 1 2 1。     

血清雌二醇放射免疫试剂盒的研制

制备了雌二醇抗体 (抗E2 6 CMO BSA)和12 5I放射配体E2 6 CMO histamine 12 5I,建立了血清雌二醇放射免疫分析方法 ,其特点是通过微量标记法提高标记物比活度 ,不用乙醚萃取直接测定血清样本 ,简化了测量步骤 ,缩短了测量时间 ,且试剂稳定时间可延长至 2个月以上。应用本法可以快速测量动物及人的血清样本 ,2 5～ 3h即可得出结果。     

关于我国农田福寿螺生物入侵需要加以研究的生态学问题

福寿螺已成为我国南方稻区主要的入侵生物之一,近年来,对水稻等农作物以及农业生物多样性和生态环境的危害日趋加重。本文对我国农田福寿螺的生物入侵危害状况进行了概述,提出了今后关于农田福寿螺生物入侵需要加以研究的生态学问题,包括农田福寿螺的生态适应性与耐性规律、农田福寿螺的种群暴发规律与预测预警、福寿螺的生态风险、农田福寿螺的综合防治与生态控制等。     

有机酸对液培玉米吸收137Cs和90Sr的影响

利用液培方法研究胡敏酸钠等有机酸盐作用下玉米幼苗对放射性核元素137Cs和90Sr的吸收速率。研究结果表明:利用有机酸盐可以降低玉米幼苗对放射性核元素的吸收速率。1低活度放射性核素水平下,对照(不加有机酸盐)的玉米幼苗中发现了97%放射性核元素137Cs,而高活度放射性核素水平中为61%;有机酸盐不同程度地降低了玉米幼苗中放射性核元素137Cs的量。在低活度水平中四苯硼钠降低137Cs的量最多, 玉米仅吸收12%,而酒石酸钾钠处理中玉米吸收量最高,为45.5%。对137Cs的吸收率,在胡敏酸钠处理中为23.9%, EDTA-Na处理中为41.3%;在高活度放射性核素水平中吸收率的顺序为四苯硼钠11%,胡敏酸钠26%,酒石酸钾钠28.7%,EDTA-Na 37%。2低活度水平下,对照中放射性核元素90Sr的56%被玉米幼苗吸收,而高活度水平中达61%。有机酸盐在低活度水平中降低放射性核元素90Sr的顺序为胡敏酸钠 23.9%,EDTA-Na 26%,酒石酸钾钠28%和四苯硼钠36%;在高活度水平中为四苯硼钠11%,EDTA-Na 24%,胡敏酸钠26%,酒石酸钾钠 31%。3低活度和高活度水平中,四苯硼钠和胡敏酸钠降低玉米幼苗体内的放射性核元素性质为最佳。4所有有机酸盐处理与对照之间的差异都达到极显著水平。     

硫对烤烟中镁吸收与积累的影响

通过液培试验研究了不同浓度硫（0.01、2、4、8、16和32mmol/L）处理对烤烟根、茎、叶及全株镁吸收及积累的影响。结果表明,2mmol/L处理显著提高了烤烟根系镁含量（0.6005%）,促进了镁的吸收与积累量,4～32mmol/L处理的镁含量、积累量及吸收速率随硫浓度增加而降低,且显著低于0.01mmol/L处...     

Determination of leghemoglobin components and xylem sap composition by capillary electrophoresis in hypernodulation soybean mutants cultivated in the field

The hypernodulation soybean mutant lines (NOD1-3, NOD2-4, NOD3-7) and their parent Williams, and the mutant En6500 and its parent Enrei were cultivated in a sandy dune field in Niigata, and the nodules and root bleeding xylem sap were sampled at 50, 70, 90, and 120 d after planting (DAP). The nodule size distribution patterns and concentration of leghemoglobin components were determined. The number of nodules of the hypernodulation mutant lines was about two to three times higher than that of the parent lines irrespective of the sampling date. At 50 DAP the nodule size was relatively smaller in the hypernodulation mutant lines, and the total dry weight of the nodules was almost the same in the mutant lines and their parents. At 70 DAP and 90 DAP, the size distribution of the hypernodulation mutant nodules became .almost the same as that of the parent lines, and both the number and total dry weight of the nodules were higher than those of the parent lines. The concentration of four Lb components was separately measured by capillary electrophoresis. The concentration of the Lb components in the hypernodulation mutant lines tended to be lower than in the parents, but the component ratios were not different between the hypernodulation mutants and their parents. Under field conditions, plant growth and nodulation characteristics were more similar between mutants and parents than in the hydroponic culture reported previously, although the mutants did exhibit hypernodulation traits. These findings suggest that the decrease in the Lb concentration and the different Lb components ratios in the mutants may be caused by secondary effects of excess nodulation, such as photosynthate deficiency, rather than by a genetic defect in mutation. The concentration of major nitrogenous compounds (allantoic acid, allantoin, asparagine, aspartic acid, and nitrate) in the xylem sap was also measured by capillary electrophoresis. The concentration of ureides and nitrate in xylem sap decreased with the plant age, but the asparagine concentration increased during the same period. The concentrations of ureides and asparagine were higher, and the nitrate concentration was lower in the mutant lines than in their parents, possibly due to the higher dependence on N₂ fixation than N0₃ ^- utilization. In the xylem sap, nitrate was the major inorganic anion followed by phosphate, sulfate, and chloride, and potassium was the major cation followed by calcium or magnesium and sodium.     

南海诸岛土壤的地球化学特征及其生物有效性

南海诸岛主要由三类土壤组成，即富磷岩性均腐土，盐成土和新成土。这些土壤均发育于具有强石灰性的生物碎屑沉积物之上。富磷岩性均腐土的元素含量与母质相比，Ｐ、Ｚｎ、Ｃｕ、Ｂａ、Ｃｄ等元素含量较高，且随成土时间的增加，其含量有增加的趋势，而Ｍｇ、Ｃａ、Ｓｒ、Ｂ、Ｖ、Ｐｂ、Ｍｏ等元素含量较低，随成土时间的增加逐渐降低。新成土和盐成土除Ｐ和Ｎａ元素含量较高外，其余元素均接近母质。南海诸岛独特的生物气候、母质等     

黄土高原褐土和黑垆土剖面中Rb和Sr分布与全新世成土环境变化

对黄土高原 3个土壤剖面Rb和Sr分布规律的研究表明 ,全新世不同阶段的黄土和土壤中Rb和Sr分布存在明显的差异 ,Rb/Sr比值的变化反映了成土环境和成土作用强度的变化。全新世早期 ,气候比较温和干燥 ,风尘堆积速率降低 ,土壤发育表现为边沉积边成土 ;全新世中期 ,气候温暖湿润 ,沙尘暴很少发生 ,风尘堆积速率极低 ,生物风化成土作用达到最强 ,以至于在黄土高原面发育黑垆土 ,在关中盆地形成褐土。到了 3 10 0多年前 ,气候恶化变干 ,风尘堆积速率加快 ,土壤严重退化。从区域上看 ,冬季风对黄土高原南部的环境效应比夏季风对北部的环境效应要强 ;黄土高原南部季风场强的变化较北部大。     

Potential Remediation of 137Cs and90 Sr Contaminated Soil by Accumulation in Alamo Switchgrass

Cesium-137 (¹³⁷Cs) and Strontium-90 (⁹⁰Sr) are radionuclides characteristic of nuclear fallout from nuclear weapons testing and nuclear reactor accidents. Alamo switchgrass (Panicum virginatum L.) is a perennial C⁴ species native to central North America that produces exceptionally high biomass yields in short periods of time. In three separate experiments, Alamo switchgrass plants were tested for their ability to accumulate ¹³⁷ Cs and⁹⁰ Sr from a contaminated growth medium. Plants in experiment 1 were grown in 33 × 20 × 7 cm plastic pans containing 2.5 kg sand. Plants in experiments 2 and 3 were grown in 30 × 3 cm diameter test tubes containing 0.3 kg growth medium. After 3 months of plant growth, either 102 Bq ¹³⁷Cs or 73 Bq⁹⁰ Sr g^?1 soil were added to the growth medium. Plants in all three experiments were grown within a greenhouse that was maintained at 22 ± 2 °C with a photosynthetic active radiation of 400–700 µmol m^?2 s^?1 and a 14–16 h photoperiod. Above-ground plant biomass did not differ between plants that were not exposed to these radionuclides (controls) and those that were exposed to growth medium containing ¹³⁷Cs or⁹⁰ Sr over the course of the experiment. Plants accumulated 44 and 36% of the total amount of ⁹⁰Sr and¹³⁷ Cs added to growth medium after the first 5 harvests. After the first two harvests, the concentration of ¹³⁷Cs and⁹⁰ Sr in plant tissue and the amount of ¹³⁷Cs or⁹⁰ Sr removed from growth medium declined with each successive harvest. Duration of exposure correlated curvilinearly with accumulation of both ⁹⁰Sr and ¹³⁷Cs by plants (r² = 0.95 and 0.78, respectively). As concentration of both ¹³⁷Cs and ⁹⁰Sr in growth medium increased, plant accumulation of both radionuclides increased and correlated curvilinearly in seedlings (r² = 0.83 and 0.89 respectively).     

EMS诱导粒用高粱的突变体筛选和鉴定

为确定粒用高粱EMS处理的最佳浓度和时间,并创制粒用高粱新种质,本研究以粒用高粱亲本系2055B和10125为试验材料,采用不同时间和不同浓度甲基磺酸乙酯（EMS）处理,调查EMS诱变对高粱出苗、叶色、叶形、穗型、育性及生育期等农艺性状的影响。结果表明,两粒用高粱亲本系的出苗率、幼苗成活率、结实率均随着EMS诱变时间和浓度的增加而降低,突变率则随着EMS诱变时间和浓度的增加而升高。同一水平EMS处理对两亲本的抑制作用不同,恢复系10125的出苗率、成苗率、结实率受抑制作用均小于保持系2055B。综合考虑出苗率、结实率和突变率等数据,2055B的最佳诱变处理时间和浓度为14 h和0.25%,10125的最佳诱变处理时间和浓度是14 h和0.3%。通过对诱变后M2代进行表型观察、鉴定和筛选,获得了早熟、矮秆、分蘖等性状的突变材料,初步构建了粒用高梁EMS突变体库,为开展高粱育种和功能基因定位提供了新种质和基础材料。     

Role of plants in the spatial differentiation of <Superscript>137</Superscript>Cs and <Superscript>90</Superscript>Sr statuses on the aggregate level

The increased concentration of an element in plant biomass compared to the soil mass is an essential condition for the differentiated spatial distribution and status of the element on the aggregate level. Two forms of this differentiation have been revealed for ¹³⁷Cs and ⁹⁰Sr. Transfer of ¹³⁷Cs from plant roots and concentration on the surface of soil aggregates have been established experimentally. Indirect data also point to the potential localization of ¹³⁷Cs on the surface of intraaggregate pores. The effect of radionuclide concentrating on the outer and inner surfaces of aggregates is due to the rapid and strong fixation of cesium microamounts by mineral soil components. ¹³⁷Cs from the surface of aggregates is more available for the repeated uptake by plant roots than from the intraped mass. The distortion of this spatial differentiation mainly occurs during the reaggregation of soil mass, which in turn decreases the availability of the radionuclide to plants. For ⁹⁰Sr, its elevated concentration in the form of organic residues has been revealed in the inter- and intraaggregate pore space. However, due to the high diffusion rate, ⁹⁰Sr is relatively rapidly (during several months under pot experimental conditions) redistributed throughout the entire volume of soil aggregates and its major part gradually passes into the phase of humic compounds, to which the radionuclide is bound by exchange sorption. The high level of the next root uptake (higher than for ¹³⁷Cs by one to two orders of magnitude) favors the permanent renewal of loci with increased ⁹⁰Sr concentrations in the inter- and intraaggregate pore space in the form of plant residues.