水稻烤田期间N2O排放及其影响因素

水稻田间实验研究了烤田期间的土壤温度、Eh、含水量和裂缝基本性质,矿质态氮以及与氮有关的酶活性的演变规律,及其对N2O排放的影响.试验表明,在水稻分蘖期间烤田,N2O有一个排放高峰,其最高值可达75.6μg·m-2·h-1.在排放高峰后,即使继续烤田,N2O的排放值也将降低.N2O排放与尿素氮肥的施用量没有明显关系.裂缝的生成,改变了N2O的日排放规律.随着烤田时间的延长,脲酶和羟胺还原酶活性呈波动变化,硝酸还原酶活性递减,亚硝酸还原酶活性极低.硝酸还原酶活性与N2O排放之间没有显著相关性.土壤中的脲酶活性与N2O日排放通量呈显著的线性正相关.在烤田期间,NO-3含量呈增加趋势.土壤中的硝态氮含量与N2O排放通量之间呈显著正线性关系.土壤中的铵态氮含量与N2O排放通量之间呈显著负线性相关.     

The effects of land use and its patterns on soil properties in a small catchment of the Loess Plateau

Due to relatively strong human activities in the hilly area of Loess Plateau,the natural vegetation has been destroyed,and landscape pattern based on agricultural land matrix was land use mosaic composing of shrub land,grassland,woolland and orchard.This pattern has an important effect on soil moisture and soil nutrients.The Danangou catchment,a typical small catchment,was selected to study the effects of land use and its patterns on soil moisture and nutrients in this paper.The results are as follows:The comparisons of soil moisture among seven land uses for wet year and dry year were performed:(1)the average of soil moisture content for whole catchment was 12.11% in wet year,while it was 9.37% in dry year;(2)soil moisture among seven land uses was significantly different in dry year,but not in wet year;(3) form wet year to dry year,the profile type of soil moisture changed from decreasing type to fluctuation-type and from fluctuant type to increasing type;(4)the increasing trend in soil moisture from the top to foot of hillslope occurred in simple land use along slope,while complicated distribution of soil moisture was observed in multiple land uses along slope.The relationships between soil nutrients and land uses and landscape positions were analysed:(1)five nutrient contents of soil organic matter(SOM),total N(TN),available N(AN),total P(TP) and available P(AP) in hilly area were lower than that in other areas.SOM content was less than 1%,TN content less than 0.07%,and TP fallow land and cropland,and higher level in soil fertility was found in crop-fruit intercropping land among croplands;(3)soil nutrient distribution and responses to landscape positions were variable depending on slope and the location of land use types.     

连续流动分析测定环境水样中的亚硝酸盐氮

利用新型连续流动分析仪对环境水样中的亚硝酸盐氮进行测定，同传统的分析方法相比，该法的分析速率可以达到50个样／h，NO2－N检出限达到0．001mg／L，加标加收率为94．0％－104．0％。     

医疗废物焚烧残余物固化技术初探

根据对医疗废物焚烧残余物中有毒有害物质的化验分析结果,确定焚烧残余物中有毒有害成分含量仍较高,部分指标超出标准值,必须对其进行稳定化/固化处理,避免对土壤及地下水环境造成污染.本文阐述了稳定化/固化处理原理及处理工艺,使医疗废物无害化、减量化和资源化的处理原则得以全面实现.     

工艺安全警示灯

某大学化学实验室的一个液氮气瓶由于超压而发生了严重的破裂,导致了较大的损失.幸运的是,事故发生在凌晨3时,建筑物内无人,因此没有人员伤亡.     

热解析气相色谱法测定土壤中苯系物

建立了用热解析气相色谱法测定土壤中苯系物的方法.采用保留时间定性,外标法定量.方法检出限分别为:苯1.8 μg·L-1、甲苯3.5 μg·L-1、乙苯7.0 μg·L-1、间二甲苯8.6 μg·L-1、对二甲苯8.6 μg·L-1、邻二甲苯9.8 μg·L-1、苯乙烯10.0 μg·L-1;加标回收率在79%～100%之间,相对标准偏差为1.5%～3.9%.方法操作简便,快速,灵敏度高,能适应现代化的应急监测.     

土壤中钼的形态分析方法研究

本文对土壤中有效钼的浸取条件进行最佳化，并利用提高灰化温度达到消除浸取剂对石墨炉原子吸收测定钼的影响，方法用于国标样品和武汉市区土壤样品中钼的形态分析，获得满意的分析结果。     

小麦重金属含量与土壤质量之间关系研究

《淮安市绿色食品基地调查以及相关研究》课题资料研究表明，小麦中各部分重金属分布是根＜茎叶＜籽粒。营养在向上输送的过程中，根系和茎叶对重金属污染物产生明显的截留作用，重金属元素被小麦吸收的难易程度分别为砷＞汞＞镉＞铅＞锰＞铬＞铜＞锌；在小麦能检出的重金属中，其含量与土壤中的含量成正相关关系，但是相关关系不显著。     

陡河三氮盐五年的污染现状及其规律

本对唐山市陡河水质进行了调查，查明了三氮盐对陡河水质产生的影响和污染现状。     

吸附再生法脱硫脱氮的实验研究

用“成型焦”，“冶金焦”进行活化，脱硫脱氮试验，再生试验，整 个过程不用水，所选用的吸附材料比表面积大，脱硫效果好，可再生循环使用。