辽河平原土壤背景值区域特征及分布规律

本文对辽河平原各土类、亚类、土属、区域土壤背景值含量范围和区域特征进行了探讨,并列出该区土壤元素间相互关系回归方程和相关矩阵,研究结果表明:(1)该区多数土壤元素含量处于世界土壤元素含量的下限;(2)土壤变异系数多为30—50%;(3)各剖面中元素迁移系数为0.9—1.0;(4)土壤元素背景值分布规律为东南部大于西、北部。     

Cd、Pb、Cu、Zn、As复合污染在农田生态系统的迁移动态研究

１９９０—１９９５年中国科学院生态网站联网研究中，在４个生态站对重金属复合污染（Ｃｄ、Ｐｂ、Ｃｕ、Ｚｎ、Ａｓ）进行了田间迁移动态实验研究，表明３年来表土中重金属元素含量缓慢下降，输出量最大支出项目为从表层向下迁移量可比作物地上部分带去量高出几十至数百倍，为污染土壤防治工作中淋洗技术运用指出了应用前景．     

Element background levels in soils of Liaohe River Plain

Soil background contents of a number of elements of different soil groups, sub-groups and genus on Liaohe River Plain were investigated. It appeared that: the background levels for most elements studied were around the lower limits of the world's averages, variation coefficients of the background content values were from 0.3-0.5 and the element migration coefficients were between 0.9 and 1.0. It was found that the element background contents in soils of eastern and southern parts of the area were generally higher than that of western and northern parts.     

Compound pollution of Cd,Pb,Cu,Zn,As in plant-soil system and its prevention

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氮添加对亚热带森林土壤有机碳氮组分的影响

为了研究氮添加对森林土壤有机碳氮组分稳定性的影响,选取我国亚热带典型常绿阔叶林(浙江桂天然林和罗浮栲天然林)和针叶林(杉木人工林),开展为期5年的野外模拟氮沉降试验,分别设置对照〔0 kg/(hm2·a),以NH₄NO₃中的N计,下同〕、低氮〔75 kg/(hm2·a)〕和高氮〔150 kg/(hm2·a)〕3个氮添加水平,用H₂SO₄分2步酸水解获得LPⅠ(活性有机库Ⅰ)、LPⅡ(活性有机库Ⅱ)和RP(惰性有机库),定量研究土壤活性和惰性有机碳氮组分以及微生物生物量碳氮对氮添加的响应. 结果表明:氮添加仅对w(LPⅡ-C)(LPⅡ-C为活性有机碳Ⅱ)有显著影响,而对其他活性和惰性有机碳氮组分的影响不显著,并且对不同林分的影响存在差异. 与对照处理相比,低氮处理下浙江桂天然林、罗浮栲天然林和杉木人工林土壤w(LPⅡ-C)的增幅分别为15.3%、29.8%、68.8%;高氮处理下杉木人工林土壤w(LPⅠ-C)(LPⅠ-C为活性有机碳Ⅰ)、w(LPⅠ-N)(LPⅠ-N为活性有机氮Ⅰ)和w(RP-C)(RP-C为惰性有机碳)的增幅分别为32.4%、78.6%、28.7%;氮添加使得土壤w(SMB-C)(土壤微生物生物量碳)的增幅为18.1%~202.5%、w(SMB-N)(土壤微生物生物量氮)的增幅为0%~103.6%;在氮添加处理下,除杉木人工林土壤SMB-N/LPⅠ-N〔w(SMB-N)/w(LPⅠ-N)〕是随着氮添加水平的增加而降低外,微生物对其他林分土壤活性有机氮的利用均表现为随着氮添加水平的增加而增加. 研究显示,氮添加对阔叶林和针叶林土壤活性和惰性有机碳氮组分的影响存在差异,但差异不显著,这与它们归还土壤的凋落物性质差异有关,并且凋落物的分解差异也可能是影响土壤不同碳氮组分变化的原因.      

流动注射分析法测定底质中总磷的研究

在一定的温度下,用硫酸和高氯酸进行消解,使不溶性磷酸盐和有机磷转化为正磷酸盐进入溶液.酸性条件下,待测液在酒石酸锑钾的催化下,与钼酸铵反应生成磷钼酸化合物.该化合物与抗坏血酸反应生成蓝色络合物.该络合物在880 nm比色.实验结果表明,底质中的总磷的RSD＜ 2％,回收率91％～103％,精密度和准确度满足实验要求.因此,流动注射分析法适用于底质中总磷的监测.     

An inventory of N(2)O emissions from agriculture in China using precipitation-rectified emission factor and background emission

Fertilized agricultural soils are a major anthropogenic source of atmospheric N₂O. A credible national inventory of agricultural N₂O emission would benefit its global strength estimate. We compiled a worldwide database of N₂O emissions from fertilized fields that were consecutively measured for more than or close to one year. Both nitrogen input (N) and precipitation (P) were found to be largely responsible for temporal and spatial variabilities in annual N₂O fluxes (N₂O–N). Thus, we established an empirical model (N₂O–N = 1.49 P + 0.0186 P · N), in which both emission factor and background emission for N₂O were rectified by precipitation. In this model, annual N₂O emission consists of a background emission of 1.49 P and a fertilizer-induced emission of 0.0186 P · N. We used this model to develop a spatial inventory at the 10 × 10 km scale of direct N₂O emissions from agriculture in China. N₂O emissions from rice paddies were separately quantified using a cropping-specific emission factor. Annual fertilizer-induced N₂O emissions amounted to 198.89 Gg N₂O–N in 1997, consisting of 18.50 Gg N₂O–N from rice paddies and 180.39 Gg N₂O–N from fertilized uplands. Annual background emissions and total emissions of N₂O from agriculture were estimated to be 92.78 Gg N₂O–N and 291.67 Gg N₂O–N, respectively. The annual direct N₂O emission accounted for 0.92% of the applied N with an uncertainty of 29%. The highest N₂O fluxes occurred in East China as compared with the least fluxes in West China.     

22种化学物和紫外线对λDNA的遗传毒性分析

采用具有遗传毒性的受试化学物处理λDNA后,经体外包装,形成噬菌体颗粒,感染宿主菌LE392,噬菌斑发生率将显著降低。用这一方法对22种化学物和紫外线测试的结果表明,丝裂霉素C等13种受试化学物和紫外线对λDNA具有遗传毒性。根据用限制性内切酶消化和凝胶电泳分析的结果认为,丝裂霉素C（MMC）、甲基磺酸乙酯（EMS）和9－氨基吖啶（9－AA）对λDNA的遗传毒作用机理,可能是它们分别造成了λDNA分子发生随机断裂、DNA交联和在碱基热点上结合的移码突变。     

东莞市工业危险废物污染防治对策研究

危险废物具有腐蚀性、毒性、易燃性、反应性和感染性等特性,对公众健康或环境构成重大或潜在的威胁.基于东莞市危险废物产生、处理、处置情况的调查分析,归纳出该市危险废物监管难点和污染防治存在的主要问题,借鉴国内外危险废物管理经验,结合东莞市实际情况,提出危险废物污染防治的对策与建议.建议加强危险废物信息管理系统建设;强化危险废物源头管理;提升处理、处置综合技术能力;发展循环经济,提高资源利用率;加强技术支撑体系建设,提升危险废物监管能力.     

三江平原小叶章湿地土壤微生物活性特征研究

选取三江平原河滨湿地、沼泽湿地和草甸化湿地3种类型小叶章湿地0~20cm土壤,研究了不同类型湿地土壤总有机碳(TOC)、微生物生物量碳(MBC)、微生物生物量氮(MBN)、基础呼吸(BR)、呼吸势(PR)、微生物熵(Cmic/Corg)和代谢熵(qCO2)变化规律.结果表明,不同类型小叶章湿地土壤总有机碳、微生物生物量碳和基础呼吸分别为46.60~75.44g.kg-1、1106.86~2319.42mg.kg-1和5.72~10.10mg.kg-.1h-1.河滨湿地和沼泽湿地土壤总有机碳、微生物生物量碳、微生物生物量氮、基础呼吸、呼吸势和微生物熵均显著高于草甸化湿地(p0.01),而河滨湿地和沼泽湿地代谢熵明显低于草甸化湿地(p0.05).各土壤微生物活性指标在河滨湿地和沼泽湿地间均无明显差异.因而,相对于河滨湿地和沼泽湿地,草甸化湿地土壤微生物活性处于较低水平,土壤总有机碳和水分含量低是限制草甸化湿地土壤微生物活性的重要因素.