Rapid degradation of butachlor in wheat rhizosphere soil

The degradative characteristics of butachlor in non-rhizosphere, wheat rhizosphere, and inoculated rhizosphere soils were measured. The rate constants for the degradation of butachlor in non-rhizosphere, rhizosphere, and inoculated rhizosphere soils were measured to be 0.0385, 0.0902, 0.1091 at 1 mg/kg, 0.0348, 0.0629, 0.2355 at 10 mg/kg, and 0.0299, 0.0386, 0.0642 at 100 mg/kg, respectively. The corresponding half-lives for butachlor in the soils were calculated to be 18.0, 7.7, 6.3 days at 1 mg/kg, 19.9, 11.0, 2.9 days at 10 mg/kg, and 23.2, 18.0, 10.8 days at 100 mg/kg, respectively. The experimental results show that the degradation of butachlor can be enhanced greatly in wheat rhizosphere, and especially in the rhizosphere inoculated with the bacterial community designated HD which is capable of degrading butachlor. It could be concluded that rhizosphere soil inoculated with microorganisms-degrading target herbicides is a useful pathway to achieve rapid degradation of the herbicides in soil.     

Influence of temperature and time on phosphorus removal in swine manure during batch aeration

This study was conducted to investigate the effects of temperature and time on the mechanisms of phosphorus removal in swine manure during aeration. Removal of soluble orthophosphates significantly increased with aeration time and temperature. Successive significant ortho-P removals were observed between days one and nine but no significant additional removals were recorded thereafter. Removals were significantly higher at temperatures of 20 and 25 degrees C than at temperatures of 5, 10, and 15 degrees C and ranged between 22.9 to 31.0%. Insoluble inorganic phosphorus also changed significantly with aeration time and temperature and with a similar trend as soluble orthophosphates. The pH of the manure explained 92 and 87% of the content of insoluble inorganic phosphorus at lower temperatures (5, 10, 15 degrees C) and at higher temperatures (20, and 25 degrees C), respectively. Organic phosphorus and aerobes growth patterns were similar to that of soluble orthophosphates removal. The rapid growth of aerobes was most probably the principal factor behind a rapid soluble ortho-P removal above 15 degrees C. The contribution of inorganic phosphates to the removal of soluble orthophosphates was approximately 61% while that due to organic P was approximately 35%. Precipitation was found to be the principal mechanism governing removal of soluble ortho-P in swine manure during aeration treatments.     

我国粮食生产布局变化特点及其成因分析

建国以来,我国粮食生产呈波浪型上了四个台阶,粮食总产量分别达到２亿ｔ、３亿ｔ、４亿ｔ、ｔｗｎ ｔ。总的来说,粮食产量呈现超伏涨落但缓慢上升的趋势。过去５０年,我国的粮食生产及布局发生了巨大的变化。首先,粮食增长逐渐由以前的单产和总产并重转变为以提高单为主。其次,粮食结构也发生了变化,很长一段时间,我国的粮食增长主要信赖于水稻增产,８０年代以后,水稻在粮食生产中的比重迅速下降,而小麦和玉米所占比重帽     

对苯二甲酸降解菌固定化生物流化床处理精对苯二甲酸废水

采用微生物筛选、纯化技术，获得了降解对苯二甲酸（TA）的YPC—TA1，YPC—TA2，YPC-TA3，YPC—TA44株菌株。将筛选出的TA降解菌固定化，处理初始TA质量浓度为2650mg／L的模拟废水，降解36h后TA去除率达100％。用TA降解芮在生物流化床反应器中处理PTA废水，最佳容积负荷为6.7kg／（m^3·d）。生物流化床反应器可在容积负荷为6．0～6．5kg／（m^3·d）的较佳条件下长周期稳定运行，COD去除率保持在91％左右，TA去除率保持在94％左右。低pH废水冲击和高容积负荷废水冲击时COD，TA去除率均明显下降，恢复正常讲水后3～4d，COD，TA去除率均恢复正常。     

Outlier identification and visualization for Pb concentrations in urban soils and its implications for identification of potential contaminated land

Outliers in urban soil geochemical databases may imply potential contaminated land. Different methodologies which can be easily implemented for the identification of global and spatial outliers were applied for Pb concentrations in urban soils of Galway City in Ireland. Due to its strongly skewed probability feature, a Box–Cox transformation was performed prior to further analyses. The graphic methods of histogram and box-and-whisker plot were effective in identification of global outliers at the original scale of the dataset. Spatial outliers could be identified by a local indicator of spatial association of local Moran's I, cross-validation of kriging, and a geographically weighted regression. The spatial locations of outliers were visualised using a geographical information system. Different methods showed generally consistent results, but differences existed. It is suggested that outliers identified by statistical methods should be confirmed and justified using scientific knowledge before they are properly dealt with.     

垃圾填埋场稳定化及其研究现状

文章对直埋场稳定化过程进行了初步描述，并从填埋气、渗滤液、垃圾组成和沉降等４个方面总结了填埋场稳定化的研究现状。     

南亚热带丘陵土壤水分循环及其有效性的研究──Ⅰ.赤红壤水库容及其有效性

阐述了南亚热带低山、丘陵、台地赤红壤总库容、贮水库容、通透库容的占有情况。探讨了水库容的有效性以及不同利用方式的赤红壤有效水库容与无效水库容的差异，并对影响赤红壤水分有效性的因素作了分析．结果表明：赤红壤贮水库容小，尤其是有效水库容小；赤红壤水分有效性主要与土壤有机质相关。     

南亚热带丘陵土壤水分循环及其有效性的研究──Ⅷ.丘陵赤红壤水分循环与平衡数学模型

依据田间实测资料，在分析丘陵赤红壤水分性质的基础上，建立了土壤有效含水量与土壤物理粘粒含量之间的数学模型、土壤水分特征曲线数学模型、土壤月均贮水量与月降雨总量之间的数学模型和径流率与土壤表层初始含水量之间的数学模型，研究了土壤水分循环与平衡数学模型及各分量与参数的确定方法.