河北省观光农业园规划中存在的问题及对策

在调查了河北省多个观光农业园和参考相关资料的基础上,根据观光农业园的功能和景观特点,将河北省的观光农业园主要分为高科技综合型观光农业园、生态休闲度假型观光农业园和特色主题型观光农业园。并针对各观光农业园规划的现状,分析了存在的定位不合理、选址盲目、缺乏景观特色、环境污染严重、服务设施匮乏以及开放时间短等问题,并针对以上问题,提出了规划应合理定位、因地制宜、突出特色、建立节约型观光农业园等相应的对策。     

Residential Preferences for River Network Improvement: An Exploration of Choice Experiments in Zhujiajiao,Shanghai, China

River networks have both ecological and social benefits for urban development. However, river networks have suffered extensive destruction as a result of urbanization and industrialization, especially in China. River restoration is a growth business but suffers poor efficiency due to a lack of social understanding. Assessing the benefits of river system restoration and recognizing public preferences are critical for effective river ecosystem restoration and sustainable river management. This study used a choice experiment with a multinomial logit model and a random parameter logit model to assess respondents’ cognitive preferences regarding attributes of river networks, and their possible sources of heterogeneity. Results showed that riverfront condition was the attribute most preferred by respondents, while stream morphology was the least preferred. Results also illustrated that the current status of each of three river network attributes was not desirable, and respondents would prefer a river network with a “branch pattern,” that is “limpid with no odor,” and “accessible with vegetation.” Estimated willingness to pay was mainly affected by household monthly income, residential location, and whether respondents had household members engaged in a water protection career. The assessment results can provide guidance and a reference for managers, sponsors, and researchers.     

计算机内灰尘有机物污染调查

通过分析从不同场所收集来的计算机内灰尘样品,以了解计算机内灰尘中有机物污染情况,以及主要有机污染物的成分和浓度,并探讨了计算机内灰尘中有机物的来源和成因。     

抓好关键环节HSE管理确保临时检修安全

因外取热器内漏及油浆系统漏点多,巴陵石化有限责任公司烯烃事业部炼油装置于2005年3月进行了临时停工检修.本次临时检修的主要工作有:两器(沉降器、再生器)清焦,内部改造,外取热器换芯子;三机系统检修,烟气能量回收、机组换烟机;油浆系统的26台油浆阀门连带法兰更换.本次检修中两器系统全停,分馏系统塔外两路循环、常压闭路循环,其余装置基本带料保压,危险性和检修难度比正常大修要大得多.时间紧,任务重,人员密集,工作点多面广,交叉作业多,作业工种多,昼夜作业多,安全管理难度大.为此,事业部HSE委员会、安环室将本次检修分成准备和实施两个阶段进行HSE管理.突出每个阶段HSE工作的重点、难点,搞好危害识别和防范措施的落实,确保本次临时检修安全无事故.     

渭河流域水体细菌群落的环境响应及生态功能预测

流域水体中细菌群落多样性及其代谢功能研究对流域水污染整治及生态修复和水体健康评价具有重要价值.基于Illumina MiSeq高通量测序技术研究渭河流域陕西境内综合治理后水体中细菌群落分布特性,利用冗余分析(redundancy analysis,RDA)方法分析了水体细菌群落与水环境因子的相关关系,并采用PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states)方法预测和评价了渭河流域细菌群落生态功能.研究结果显示,变形菌门、放线细菌门、蓝藻门和拟杆菌门细菌是水体细菌群落中的主要菌门,占整个细菌群落的相对丰度高达85%,这类细菌与水体中的TP、NO_2~--N、NO_3~--N和TN呈显著的正相关关系(P=0. 02 0. 05);灞河入渭口下游(S5)细菌群落丰度最高,皂河(S4)细菌群落丰度最低;渭河流域水体致使人类患传染性疾病的可能性较大,且对生物体内分泌系统有较大的影响.本研究成果可为渭河流域水环境健康有序发展提供理论基础.     

老化作用对微塑料吸附四环素的影响及其机制

微塑料（MPs）和抗生素同为新型污染物,微塑料可以在水环境中吸附抗生素并作为其载体而共同迁移,而微塑料会在环境中不断地老化,其吸附能力和吸附机制也会随之改变.以聚乙烯（PE）和聚苯乙烯（PS）为目标MPs,通过紫外法（UV-254）进行照射,对比老化前后微塑料颜色、表面形态和官能团等理化特性改变,以及其对四环素（TC）吸附的影响,探讨了相关影响机制.结果表明,准二级动力学模型能较好地模拟吸附过程,在24 h内达到吸附平衡,老化微塑料对TC的吸附量明显高于原始微塑料,且PS的吸附量高于PE.Langmuir和Freundlich等温吸附方程均能较好地描述吸附等温试验数据,TC在微塑料上的吸附是自发的和吸热的物理吸附过程,老化作用对微塑料吸附热力学特性无明显影响.随着pH值的增加,吸附量先增大后减小,老化前后的微塑料均在pH=5时达到最大吸附量.紫外老化增加了微塑料的比表面积,生成了—C＝O、—OH和O＝C＝O等含氧官能团,改变了微塑料的理化特性,从而改变了微塑料对TC的吸附机制：相比原始PE微塑料,老化PE除了疏水分配、范德华力和静电作用外,孔填充也是吸附的重要机制;原始PS微塑料的主要吸附机制为疏水分配、范德华力、π-π作用和静电作用,老化PS则增加了氢键和孔填充作用.     

渭河关中段典型支流非点源污染监测与负荷估算

2009年,对渭河关中段3条典型支流泾河、沣河和灞河进行了洪水期和非洪水期水质水量同步监测,水质监测指标包括COD、DP、TP、NH4+-N和TN.根据监测结果及水文站实测流量资料,分别采用水文分割法和平均浓度法对各条支流的非点源污染负荷进行了计算,分析了非点源污染的特点.结果表明：①3条河流洪水期间各指标的平均浓度基...     

塔中绿化带沙丘剖面地温分析

2009年8月4日～7日,利用MicroLite地温表(16 K LITE5016)获取了塔克拉玛干沙漠腹地塔中站(东面)人工绿化带沙丘剖面上的底部、中部以及坡顶的地温(0,10,20 cm地温).选取整点数据,分析地温在72 h内的变化.结果表明:①绿化带沙丘底部、中部、坡顶0 cm地温最大值出现在有沙尘天气时,分别为60.53,59.33,50.35℃,沙尘和阵雨天气对0 cm地温的影响很大,有阵雨时地温偏低,沙尘天气时底部和中部只出现1个极大值、坡顶有2个极大值;②10 cm地温变化具有规律性,上升时段的平均变化速率比下降时段大,10 cm的地面升温速率快、降温速率慢;③20 cm地温变化较缓,受天气变化的影响很小,沙丘底部、中部、坡顶20 cm地温在72 h中最大差值分别为3.95,3.67,2.76℃.     

Toxicological effects involved in risk assessment of rare earth lanthanum on roots of Vicia faba L. seedlings

Combined chemical analyses and biological measurements were utilized to investigate potential toxicological effects and possible mechanisms involved in risk assessment of rare earth elements (REEs) on Vicia faba L. seedlings, which were hydroponically cultivated and exposed to various concentrations of lanthanum (La) for 15 days. The results showed that La contents in both the solution and roots increased with the increase of extraneous La, contributing to hormetic dose responses of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and endoprotease (EP) isozymes activities, and HSP 70 production enhanced at low doses but suppressed at higher doses of La. These physiological responses constituted antioxidant and detoxification systems against La-induced oxidative stress. The elevated La levels also contributed to oxidatively modified proteins, which were most responsible for subsequent cell death and growth retardation of the roots. By combination of hormetic and traditional threshold dose levels, the threshold dose range was deduced to be 108-195 μg La/g dry weight in the roots, corresponding to 0.90-3.12 mg/L of soluble La in the culture solution. It suggests that persistent applications of REEs may lead to potential ecological risk in the environment.     

中亚热带不同林龄马尾松林土壤酶学计量特征

土壤酶活性是表征土壤微生物养分需求与养分限制状况的重要指标.本文以中亚热带不同林龄(9、17、26、34和43 a)马尾松人工林为研究对象,通过测定β-葡萄糖苷酶(BG)、N-乙酰-β-氨基葡萄糖苷酶(NAG)、亮氨酸氨基肽酶(LAP)、酸性磷酸酶(AP)、多酚氧化酶(POX)和过氧化物酶(POD)活性,并计算土壤酶化...