壳聚糖衍生物修饰电极测定水中NO_2~-的研究

利用水杨醛对壳聚糖进行改性,合成壳聚糖席夫碱类衍生物(S-CTS),将其滴涂在玻碳电极表面成膜。用循环伏安法研究了该修饰电极对NO2-的电催化作用。实验结果表明,以0.1mol/LpH4.0的B-R缓冲溶液为底液,还原峰电流与NO2-浓度在1.8×10-1～70mg/L范围内呈良好的线性关系,相关系数为0.9915,检出下限达4.6×10-3mg/L。用于水样测定,结果满意。     

贡嘎山本底站大气中VOCs的研究

为研究中国西南地区大气中挥发性有机物（VOCs）区域性本底浓度和变化特征,利用不锈钢钢瓶采样、三步冷冻浓缩进样-气相色谱/质谱联用技术（GC/MS）,测定了贡嘎山大气本底站大气中的VOCs组成、浓度及季节变化,并利用PCA（principal component analysis）受体模型对大气中VOCs来源进行了初步分析.结果表明,贡嘎山地区TVOCs和NMHCs的年平均浓度（体积分数）分别为9.40×10-9±4.55×10-9和7.73×10-9±4.43×10-9,且两者的最高和最低浓度都出现在同一次采样.在TVOCs中,芳香烃所占比例最大,为37.3%,烷烃（30.0%）和卤代烃（19.8%）次之,烯烃的比例最低,为12.9%.通过PCA受体模型分析发现,贡嘎山地区大气中VOCs的主要来源可以归结为交通源、生物源和燃烧源.贡嘎山地区大气中TVOCs呈现明显的季节变化,变化特征为秋季〉冬季〉春季〉夏季,秋季和冬季大气中的TVOCs浓度分别极显著（P〈0.01）和显著地高于夏季（P〈0.05）,由于光化学性质的差异,4种类型的VOCs季节变化也呈现出不同的特征.异戊二烯是生物源的重要排放物,其排放速率与大气温度呈指数相关,在20℃以上随着温度的升高排放速率明显增强,其最高和最低值分别出现在夏季的下午和冬季的上午.与其他地区的研究结果相比,贡嘎山地区TVOCs的排放处于中等水平,有着明显的本底站排放特征.     

扩底桩抗拔承载特性数值分析

基于通用软件ABAQU S,建立了扩底抗拔桩三维弹塑性有限元模型,通过对模型的计算与分析,探讨了扩底桩的抗拔承载特性。为验证数值模型的可靠性,将数值计算得到的荷载—位移关系曲线与试桩资料进行比较,两者吻合较好,表明本文所建立的模型可较好地模拟扩底抗拔桩的工作性状。通过计算与分析,探讨了扩底抗拔桩的轴力、侧摩阻力分布特征,桩身和扩大头周围土体变形与塑性应变的发展规律,以及扩大头的挤压作用对扩大头周围土体竖向应力的影响。同时,通过变动参数研究了扩大头的形状、土体的性质对扩底桩抗拔承载力的影响,结果表明,扩大头直径和扩大头周围土体的性质对抗拔承载力的影响较大,而扩底高度的影响相对较小。     

渭河关中段生态基流保障的水质水量响应关系研究

以渭河关中段为研究对象,结合渭河关中段的水文和水质特征,建立了渭河关中段水质水量响应关系计算程序.设置现状年(2007年)生态基流调控方案,通过渭河关中段生态基流保障调控模型计算渭河关中段各断面调控后的流量.将调控后的各断面流量输入渭河关中段水量水质响应关系的Visual Basic程序中,计算得到各断面水质与枯水期平均流量、最小流量及90％基流保证率流量的响应关系.结果表明,林家村断面至常兴桥断面水质相对较好,且优于地表水环境质量标准(GB 3838-2002)V类水标准,兴平断面至新丰镇桥断面之间水质相对较差.本文可为渭河关中段枯水期生态基流保障及水质改善提供技术支持.     

广西北部湾蔬菜种植基地土壤中代森锌类农药残留调查

采用顶空-气相色谱-质谱法,对南宁、北海、钦州和防城港等4个北部湾区域城市蔬菜种植基地60份土壤样品中的代森锌类农药残留进行检测。结果表明,南宁市的15份土壤样品均未检出代森锌类农药残留;北海市有5份土壤样品检出代森锌类农药残留,检出率为33.3%,其质量比范围为0.005 2 mg/kg~0.034 6 mg/kg;钦州和防城港2市30份土壤样品均检出代森锌类农药残留,检出率为100%,其质量比范围为0.004 9 mg/kg~0.674 mg/kg。     

用底栖动物评价底质

以底栖动物作为底层水环境和底泥环境长期影响的指标,利用生物指数和种群结构的变化对底质进行评价和分析。     

楼顶式移动基站电磁辐射污染调查

对南通市楼顶式移动基站电磁辐射污染进行了调查。结果表明,南通市418个楼顶站基站周边地面50 m范围内电磁辐射功率密度值均能满足《电磁环境控制限值》(GB 8702—2014)的要求;楼顶美化天线、集束天线和景观塔等建设较晚的楼顶塔形地面电磁辐射强度相对较小,楼顶角钢塔、拉线塔和抱杆等建设较早的塔形地面电磁辐射强度相对较大;楼顶塔所在楼顶平台监测值存在轻度超标的情况。提出,应严格控制楼顶塔所在楼顶的人员可达性,即基站电磁辐射防护区应高出楼顶2 m以上,避免公众进入基站电磁辐射防护区内,受到基站天线的过量辐射影响。     

通讯基站环境电磁辐射监管平台设计及运用

从移动通信基站电磁辐射的特点及管理要素入手,针对通信基站环境监管环节中存在的问题,设计通讯基站环境电磁辐射监管平台,提出合理有效的环境监管措施,实现历史监测数据、环评、验收资料电子化,信息公开化;通过平台开展电磁知识宣传教育,建立网络互动,有效遏制通讯基站建设违规行为,提高环保监管效率。     

Environmental solutions sparked by environmental history

Environmental solutions require a decision-making process that is ultimately political, in that they involve decisions with uncertain outcomes and stakeholders with conflicting viewpoints. If this process seeks broad alignment between the government and public, then reconciling conflicting viewpoints is a key to the legitimacy of these decisions. We show that ecological baselines can be particularly powerful tools for creating a common understanding for public support (legitimacy) and conformity to new rules or regulations (legality) that enable the solution. They are powerful because they move the discussion of solutions from the abstract to the concrete by providing a conceptual model for a common expectation (e.g., restoring habitat). They provide narratives of the past (ecological histories) that readjust the future expectations of individuals on how to perceive and respond to new policy. While ecological baselines offer scientists benchmarks for reinstating ecological functions, they also normalize public and government discussion of solutions. This social normalization of public issues may assist government policy and influence social views, practices, and behaviors that adopt the policy. For science to more effectively inform conservation, we encourage interdisciplinary thinking (science- and human-centered) because it can provide public support and government legitimacy for investing in environmental solutions.     

Test case based risk predictions using artificial neural network

INTRODUCTION: The traditional fuzzy-rule-based risk assessment technique has been applied in many industries due to the capability of combining different parameters to obtain an overall risk. However, a drawback occurs as the technique is applied in circumstances where there are multiple parameters to be evaluated that are described by multiple linguistic terms. METHOD: In this study, a risk prediction model incorporating fuzzy set theory and Artificial Neural Network (ANN) capable of resolving the problem encountered is proposed. An algorithm capable of converting the risk-related parameters and the overall risk level from the fuzzy property to the crisp-valued attribute is also developed. Its application is demonstrated by a test case evaluating the navigational safety within port areas. RESULTS: It is concluded that a risk predicting ANN model is capable of generating reliable results as long as the training data takes into account any potential circumstance that may be met. IMPACT ON INDUSTRY: This paper provides safety assessment practitioners with a novel and flexible framework of modelling risks using a fuzzy-rule-base technique. It is especially applicable in circumstances where there are multiple parameters to be considered. The proposed framework also enables the port industry to manage navigational safety in a rational manner.