中国城镇化、配套产业发展与农村居民消费拉动

农村居民消费不足是现阶段我国经济失衡的一大表现,加快我国城镇化建设的重要目标之一在于促进农村居民消费,于此同时,城镇化建设对农村居民消费的影响,还受制于配套产业发展水平的高低。本文首先探索性地构建城镇化影响农村居民消费的理论解释。在此基础上,采用2000—2012年我国30个省(市、区)的数据,运用双向固定效应模型,实证检验了城镇化水平、产业发展与农村居民消费之间的关系,其中重点从地区工业发展水平和服务业发展水平两个方面探讨配套产业发展的调节效应。此外,在估计过程中考虑到研究对象的区域异质性,对于东、中、西部分样本还进行了分组对比考察。本文研究结果表明:(1)城镇化能够显著促进农村居民的消费,工业发展水平具有明显的正向调节作用,但服务业发展水平的调节作用并不显著;(2)东部地区相比中、西部地区,由于配套优势,城镇化的推进更能有效地促进农村消费的提升;(3)东部地区工业发展水平的正向调节效应显著存在于工业化水平由最低端向中端攀升的过程中,而在西部地区,由于工业发展低效益伴随的农村劳动力外流以及对当地耕地的低效利用,工业发展反而削弱了城镇化的正向调节作用。因此,为了更好地通过促进农村消费实现扩大内需,本文研究的政策建议包括:在当前我国城镇化建设进程中,要特别注重对配套产业特别是工业的培育,防范产业空心化风险,稳定就业。东部工业发展的重点应是扶持工业最不发达区域,缩小区域之间工业发展差距,西部工业发展的重点则在于提高工业发展的效益,引导农民工回流,调整经济发展结构和模式。     

基于典型道路谱的模拟运输振动试验方法研究

针对深圳某一路段使用美国Lansmont公司开发的SAVER环境应力记录仪记录汽车运输过程中的环境应力,利用相关处理软件整理分析数据,最后在实验室中的通过电磁振动台的随机振动模式来进行模拟重现从而实现“Fieldtolab”。该方法用短时间的实验室内试验来代替长时间的实际运输过程,不仅绿色环保,而且省时省力,是一种值得推广的试验方法。     

陇东油田井场油泥微生物处理应用

为解决石油开采及油井措施作业过程中原油散落井场产生油泥,污染井场周围土壤、水体、空气的现状,文章介绍了一种针对生态环境脆弱的陇东油田井场油泥微生物处理技术,可以实现对井场油泥环保、经济、有效处理。     

Possible alkylation of inorganic Hg(II) by photochemical processes in the environment

Contamination of surface waters by pesticides continues to be the focus of concern for water authorities due to the growing evidence of their deleterious effects on aquatic life. In this context, the present work investigates the occurrence of 16 selected pesticides belonging to the classes of triazines, phenylureas, organophosphates, chloroacetanilides and thiocarbamates in surface waters from the Llobregat River (NE Spain) and some of its tributaries (Anoia and Rubí) and assesses their potential impact on the aquatic organisms by applying a recently developed index, the Short-term Pesticide Risk Index for the Surface Water System (PRISW-1), which takes into account the pesticides concentrations and their overall toxicity against three aquatic organisms (algae, Daphnia, and fish). Chemical analysis, performed by means of a fully automated method based on isotope dilution on-line solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry (on-line SPE-LC-ESI-MS/MS), revealed diuron and diazinon as the most ubiquitous and abundant compounds with levels up to 818 and 132 ng L⁻¹, respectively. Total pesticide concentrations, which in only 1 out of 66 samples surpassed 500 ng L⁻¹, were higher in the tributaries than in the river but their contribution in terms of mass-loads to the overall pesticide pollution of the Llobregat River was relatively small. Contamination increased downstream of the river and was clearly influenced by rainfall and hence river flow. Application of the PRISW-1 index indicated that, although pesticides levels fulfilled the European Union Environmental Quality Standards (EQS) for surface waters, the existing pesticide contamination poses a low to high ecotoxicological risk for aquatic organisms, that algae and macro-invertebrates are at higher risk than fish, and that the organophosphates diazinon and malathion and the phenylurea diuron are the major contributors to the overall toxicity and therefore the most problematic compounds.     

Brassinosteroid alleviates phenanthrene and pyrene phytotoxicity by increasing detoxification activity and photosynthesis in tomato

The present study was carried out to investigate the effects of exogenously applied 24-epibrassinolide (BR) on growth, gas exchange, chlorophyll fluorescence characteristics, lipid peroxidation and antioxidant systems of tomato seedlings grown under different levels (0, 10, 30, 100 and 300 μM) of phenanthrene (PHE) and pyrene (PYR) in hydroponics. A concentration-dependent decrease in growth, photosynthetic pigment contents, net photosynthetic rate (Pn), stomatal conductance (Gs), maximal quantum yield of PSII (Fv/Fm), effective quantum yield of PSII (Φ_PSII), photochemical quenching coefficient (qP) has been observed following PHE and PYR exposure. By contrast, non-photochemical quenching coefficient (NPQ) was increased. PHE was found to induce higher stress than PYR. However, foliar or root application of BR (50 nM and 5 nM, respectively) alleviated all those depressions with a sharp improvement in the activity of photosynthetic machinery. The activities of guaicol peroxidase (GPOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) as well as content of malondialdehyde (MDA) were increased in a dose-dependent manner under PHE or PYR treatments. Compared with control the highest increments of GPOD, CAT, APX, GR and MDA by PHE/PYR alone treatments were observed following 300 μM concentration, which were 67%, 87%, 53%, 95% and 74% by PHE and 42%, 53%, 30%, 86% and 62% by PYR, respectively. In addition, both reduced glutathione (GSH) and oxidized glutathione (GSSG) were induced by PHE or PYR. Interestingly, BR application in either form further increased enzymatic and non enzymatic antioxidants in tomato roots treated with PHE or PYR. Our results suggest that BR has an anti-stress effect on tomato seedlings contaminated with PHE or PYR and this effect is mainly attributed by increased detoxification activity.     

Seasonal variations of CH(4) and N(2)O emissions in response to water management of paddy fields located in Southeast China

Water management is one of the most important practices that affect methane (CH₄) and nitrous oxide (N₂O) emissions from paddy fields. A field experiment was designed to study the effects of controlled irrigation (CI) on CH₄ and N₂O emissions from paddy fields, with traditional irrigation (TI) as the control. The effects of CI on CH₄ and N₂O emissions from paddy fields were very clear. The peaks of CH₄ emissions from the CI paddies were observed 1-2 d after the water layer disappeared. Afterward, the emissions reduced rapidly and remained low until the soil was re-flooded. A slight increase of CH₄ emission was observed in a short period after re-flooding. N₂O emissions peaks from CI paddies were all observed 8-10 d after the fertilization at the WFPS ranging from 78.1% to 85.3%. Soil drying caused substantial N₂O emissions, whereas no substantial N₂O emissions were observed when the soil was re-wetted after the dry phase. Compared with TI, the cumulative CH₄ emissions from the CI fields were reduced by 81.8% on the average, whereas the cumulative N₂O emissions were increased by 135.4% on the average. The integrative global warming potential of CH₄ and N₂O on a 100-year horizon decreased by 27.3% in the CI paddy fields, whereas no significant difference in the rice yield was observed between the CI and TI fields. These results suggest that CI can effectively mitigate the integrative greenhouse effect caused by CH₄ and N₂O emissions from paddy fields while ensuring the rice yield.     

废水营养比对固定化藻菌去除污染物的影响及动力学研究

海藻酸钙作载体的固定化藻菌小球,经壳聚糖覆膜后,用于模拟废水的处理。通过研究废水初始氨氮浓度及碳氮比对固定化藻菌小球处理效果的影响,发现初始氨氮浓度为50 mg/L时,氨氮的去除率达最高值74.4%;碳氮比为35∶1时,COD去除率达最高值77.7%。系统最佳氮磷比与碳氮比分别为5∶1和35∶1。固定化藻菌降解有机物的动力学过程为一级不可逆生化反应过程,其降解速率常数约为0.099 h-1。     

高效液相色谱法检测水中5种微囊藻毒素

使用Agilent1260型高效液相色谱仪,建立定量测定天然水体中5种微囊藻毒素（MC-RR、YR、LR、LA、LY）的分析方法。比较甲醇/三氟乙酸（TFA）水溶液与甲醇/磷酸两种流动相体系,待测物质的响应程度,结果发现,TFA作为缓冲溶液时,基线较磷酸稳定,因此,选择甲醇/TFA水溶液作为流动相。比较不同TFA体积比例,待测物质的分离程度,结果显示,甲醇/0.02%的TFA水溶液作为流动相时,5种MCs含量的分离度较好。比较等度和梯度洗脱条件,发现,梯度洗脱条件5种MCs的分离度较等度洗脱条件好。该方法 MC-RR、YR、LR、LA、LY的最低检出限（LOD）分别为0.015、0.035、0.018、0.032和0.026μg/L,最低定量限（LOQ）分别是0.049、0.117、0.062、0.106和0.086μg/L。在0.10～1.50μg/mL的线性范围内,相关系数R2≥0.99,实际水样回收率为73.9%～103.3%。