Nitrate in shallow groundwater in typical agricultural and forest ecosystems in China, 2004-2010

The nitrate-nitrogen(NO 3-N) concentrations from shallow groundwater wells situated in 29 of the Chinese Ecosystem Research Network field stations,representing typical agroand forest ecosystems,were assessed using monitoring data collected between 2004 and 2010.Results from this assessment permit a national scale assessment of nitrate concentrations in shallow groundwater,and allow linkages between nitrate concentrations in groundwater and broad land use categories to be made.Results indicated that most of the NO 3--N concentrations in groundwater from the agroand forest ecosystems were below the Class 3 drinking water standard stated in the Chinese National Standard:Quality Standard for Ground Water(≤ 20 mg/L).Over the study period,the average NO 3--N concentrations were significantly higher in agro-ecosystems(4.1 ± 0.33 mg/L) than in forest ecosystems(0.5 ± 0.04 mg/L).NO 3-N concentrations were relatively higher(> 10 mg N /L) in 10 of the 43 wells sampled in the agricultural ecosystems.These elevated concentrations occurred mainly in the Ansai,Yucheng,Linze,Fukang,Akesu,and Cele field sites,which were located in arid and semiarid areas where irrigation rates are high.We suggest that improvements in N fertilizer application and irrigation management practices in the arid and semi-arid agricultural ecosystems of China are the key to managing groundwater nitrate concentrations.     

节俭还是低碳——我国语境下居民低碳行为探讨

为了解低碳在我国居民中的推广程度,通过问卷法对南京市某社区居民进行实地调查。结果发现:大部分居民由于受节俭文化的影响往往将低碳当作节俭进行理解,表现在行为上就是节俭行为与低碳行为混杂。但从社会文化角度分析,节俭与低碳并不等同,两者既有区别又有联系。因此,在我国语境下推行低碳既要注意到节俭与低碳的区别,又要充分挖掘节俭文化中蕴含的低碳内容,促进低碳社会的构建。     

鸡粪与中药渣共堆肥对抗生素抗性基因的影响

畜禽粪便是抗生素抗性基因(antibiotic resistant genes,ARGs)进入环境的重要途径,为了削减畜禽粪便中的ARGs,在为期46 d的鸡粪与中药渣共堆肥后,对不同阶段ARGs和可移动基因元件(mobile gene elements,MGEs)的丰度通过实时定量PCR进行检测. 100种ARGs中检测到21种,以及2种整合酶基因(int I1和int I2)和3种转座酶基因(tnp A-01、tnp A-02和tnp A-03).结果表明,在堆肥过程中5种MGEs均显著降低,其中tnp A-01和tnp A-02去除效果最好,减少了两个数量级;氨基糖苷类抗性基因aac A/aph D和aad E显著性降低(P 0. 05);β-内酰胺类抗性基因bla OXA1与堆肥天数显著相关(P=0. 016),其去除率为78. 63%;林可酰胺类抗性基因均随堆肥时间显著降低,平均去除率为90. 39%;四环素类抗性基因的去除效果相差较大,tet G降低了99. 77%,tetR仅降低了31. 72%;喹诺酮类抗性基因qnr D去除率最高为99. 89%;磺胺类中sulⅢ的去除率高达99. 88%,而sulⅠ呈增长趋势. ARGs与MGEs相关性表明tnp A-01与ARGs之间具有显著相关性(P 0. 05). ARGs随堆肥时间的变化趋势表明,中药渣与鸡粪共堆肥可显著降低ARGs丰度,从而降低畜禽粪便在农田施用中ARGs扩散的风险.     

面向中医理论的安全系统比较与隐患治理思辨

为了给企业的隐患治理及安全管理提出全新且符合国情的系统治理方案,提出基于传统中医理论理解的系统隐患治理范式。首先,基于中医理论分析了生产系统与人体系统之间的内在关联,首次提出了生产系统结构要素、功能要素和要素流的关系。通过分析系统安全管理与中医诊治之间本质联系,从管理对象和方法角度阐述结合中医诊治原理的必要性;从整体观、动态观和人文观等3个方面对中医思想和安全系统思想的共性进行了比较。其次,建立了生产系统隐患治理范式模型,从治理对象确定、分析系统机理到治理方法探索三方面解释了生产系统隐患治理范式的内涵。同时构建了“阴阳五行”观下的生产系统五行图。最后,用天津港“8·12”事故进行实证分析。分析结果表明生产系统隐患治理范式可以实现对复杂企业生产系统隐患及事故进行深入分析。研究表明:生产系统隐患治理范式可以指导隐患治理工作的进行,构建的基本方法对丰富隐患治理体系提供全新启示。     

农户经营杉木林的碳汇供给及其影响因素

基于我国南方集体林区浙江、江西、福建三省202户农户杉木林经营数据,结合已有生长模型,采用生物量转换和扩展因子法, 测算了杉木林生态系统固碳量,并采用修正的Hartman模型,在林地期望价值最大化的决策目标下,估算出了碳汇价格、利率、木材价 格变动对杉木林碳汇供给量的影响.结果表明:①最优轮伐期及碳汇供给量与碳汇价格成正相关,与利率、木材价格成负相关.②在碳汇价格变化情况下,最优轮伐期由大到小依次为,劣等地＞中等地＞优等地,相反,碳汇供给量依次为,优等地＞中等地＞劣等地,劣等地的最优轮伐期和碳汇供给量变动幅度要明显大于中等地和优等地.③利率在7％-8％变动时,优等地的最优轮伐期和碳汇供给量均未发生变化;利率在4％-5％变动时,中等地最优轮伐期和碳汇供给量均未发生变化;而在1％-8％的变动区间,劣等地的最优轮伐期和碳汇供给量均在不断缩短和降低.④当木材价格上升10％或下降10％时,对优等地的最优轮伐期和碳汇供给量均未产生影响;对中等地而言,仅当木材价格下降10％时,最优轮伐期和碳汇供给量均发生变动;而对劣等地而言,木材价格上升或下降都对两者产生影响.研究得出如下结论:碳汇价格、利率、木材价格对杉木林经营最优轮伐期及杉木碳汇供给量有重要影响,在碳汇价格、利率、木材价格变化情况下,不同立地条件的碳汇供给价格弹性、利率弹性、木材价格弹性存在显著差异.立地条件通过影响杉木营林成本和产出量,从而对杉木林经营的最优轮伐期及碳汇供给量产生较大影响,立地条件越差的地块对碳汇供给量越敏感,随着碳汇价格逐步上升、利率和木材价格的逐步提高,碳汇供给变化为劣等地大于中等地和优等地,而碳汇供给量为优等地大于中等地和劣等地.     

ANALYSIS OF SEISMIC TREND & HAZARDS OF THE CHINESE MAINLAND IN THE COMING YEARS

Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｓｉｎｃｅａ 7.9ＭｓｅａｒｔｈｑｕａｋｅｔｏｏｋｐｌａｃｅｉｎＭａｎｉｉｎＳｅｐｔｅｍｂｅｒ 1997,ｎｏｓｈａｌｌｏｗ ｆｏｃｕｓｅａｒｔｈｑｕａｋｅｓａｂｏｖｅ 7ＭｓｈａｖｅａｔｔａｃｋｅｄｔｈｅＣｈｉｎｅｓｅｍａｉｎｌａｎｄｉｎｔｈｅｐａｓｔｆｅｗ ｙｅａｒｓ.Ｔｈｅｓｔｒｏｎｇｅｓｔｓｈａｌｌｏｗ ｆｏｃｕｓｅａｒｔｈｑｕａｋｅｉｎ 1999ｒｅａｃｈｅｄｏｎｌｙ 5 .6Ｍｓａｎｄｔｈａｔｉｎ 2 0 0 0ｗａｓ6 .6Ｍｓ.Ｔｈｅｒｅｗｅｒｅｊｕｓｔｔｈｒｅｅｅａｒｔｈｑｕａｋｅｓｒｅ…     

First-trimester diagnosis of hydrolethalus syndrome in a Chinese family

We report a case resembling hydrolethalus syndrome in a Chinese family. Fetal polydactyly, syndactyly, encephalocele and cardiac malformation were detected on ultrasound examination at 12 weeks' gestation. Termination of pregnancy was performed, and postmortem examination confirmed the findings. This is the first report of a first-trimester prenatal diagnosis of hydrolethalus syndrome in the Chinese population. Copyright © 2004 John Wiley & Sons, Ltd.     

SEISMIC DISASTERS IN CHINESE MAINLAND IN 2000

ＯｕｔｌｉｎｅｓｏｆｅａｒｔｈｑｕａｋｅｓｉｎＣｈｉｎａｉｎ 2 0 0 0　ＴｈｅｇｅｎｅｒａｌｌｅｖｅｌｏｆｓｅｉｓｍｉｃａｃｔｉｖｉｔｙｉｎＣｈｉｎａｉｎ 2 0 0 0ｗａｓｌｏｗｅｒｔｈａｎｉｎ 1 999,ｗｉｔｈａｔｏ ｔａｌｏｆ 50ｅａｒｔｈｑｕａｋｅｓ (Ｍｓ≥ 5.0 ) (ｓｅｅＴａｂｌｅ 1 ) ;ｂｕｔｔｈａｔｉｎＣｈｉｎｅｓｅｍａｉｎｌａｎｄｗａｓｓｌｉｇｈｔｌｙｈｉｇｈｅｒ ,ｗｉｔｈ 30ｅａｒｔｈｑｕａｋｅｓ(Ｍｓ≥ 5.0 ) ,ｉｎｃｌｕｄｉｎｇ 1 3ｑｕａｋｅｓｏｃｃｕｒｒｉｎｇｉｎＱｉｎｇｈａｉＰｒｏｖｉｎｃ…     

Non-thermal plasma treatment of Radix aconiti wastewater generated by traditional Chinese medicine processing

The wastewater effluent from Radix aconiti processing, an important step in the production processes of traditional Chinese medicine (TCM), is a type of toxic wastewater and difficult to treat. Plasma oxidation methods have emerged as feasible techniques for effective decomposition of toxic organic pollutants. This study examined the performance of a plasma reactor operated in a dielectric barrier discharge (DBD) to degrade the effluent from R. aconiti processing. The effects of treatment time, discharge voltage, initial pH value and the feeding gas for the reactor on the degradation of this TCM wastewater were investigated. A bacterium bioluminescence assay was adopted in this study to test the toxicity of the TCM wastewater after non-thermal plasma treatment. The degradation ratio of the main toxic component was 87.77% after 60 min treatment with oxygen used as feed gas and it was 99.59% when the initial pH value was 8.0. High discharge voltage and alkaline solution environment were beneficial for improving the degradation ratio. The treatment process was found to be capable of reducing the toxicity of the wastewater to a low level or even render it non-toxic. These experimental results suggested that the DBD plasma method may be a competitive technology for primary decomposition of biologically undegradable toxic organic pollutants in TCM wastewater.     

镉污染土壤施硒对植物生长及根际镉化学行为的影响

采用根箱培养的方式,研究了在不同镉污染水平(0.5 mg·kg-1、5 mg·kg-1土壤)的酸性黄棕壤中施用外源硒对小白菜生长、光合特性及根际土壤中镉的化学行为影响.结果表明:镉污染土壤中施硒可显著增加小白菜的生物量,增强小白菜叶片的光合速率和蒸腾速率;镉污染严重时,施硒还可提高小白菜的气孔导度;施用适量硒(0.25 mg·kg-1)可显著降低小白菜地上部镉含量,其中镉污染浓度较低(0.5 mg·kg-1)时,该效果达显著水平.在镉污染程度低(0.5 mg·kg-1)的土壤施用适量硒(0.25 mg·kg-1),可显著降低土壤交换态镉含量,其中,根际和非根际土壤交换态Cd含量分别降低了22.20%和43.79%.外源Se有效地降低了土壤Cd的生物有效性,这种作用在Se的施用浓度较低时表现更加明显;当Cd污染浓度较高时,土壤Cd形态分布相对稳定,外源Se对根际和非根际土壤Cd形态分布的影响不显著.研究结果为深入揭示Se对菜地Cd污染的调控机理提供理论参考.