基于鱼骨图和层次分析法的石油静电事故影响因素分析

针对石油静电事故影响因素的复杂性、多层次性和不确定性的特点,采用鱼骨图分析法,找出了引发石油静电事故的影响因素,确定出6个主因素、25个子因素的石油静电事故评价指标体系。应用层次分析法确定了各个影响因素的重要程度,分析出导致石油静电事故的重要因素。结果表明,6个主因素中,隶属于生产操作工艺和安全生产管理的操作错误、人体静电和接地故障3个主因素权重之和高达0.792,是引发石油静电事故的主导因素;子因素中预防的重点应放在喷溅式装卸油、化纤品与人体摩擦和接地线损坏方面。鱼骨图分析法和层次分析法的联合应用,合理地解决了石油静电事故影响因素分析难题,具有一定的推广应用价值。     

一种利用AIS数据计算受限水域内航标安全距离的方法

AIS数据详细记录了特定水域的船舶位置、船首向和尺寸等数据,可用于计算受限水域内航标安全距离。按一定标准网格化目标航标附近水域,统计周围航行的他船船体出现在每一个网格中的频数,形成他船航迹的网格频数图。按长度尺寸分类,将同类他船航迹网格频数图叠加,形成特定类型船舶的航迹网格频数图。按频数大小填充颜色,可清晰地显示航标附近他船安全通行状态下与航标保持的距离。实验选取上海港航标附近水域海量AIS数据,获取了60~79m,80~99m,100~129m,130~159m船舶航迹形成的网格频数图,结果显示,四类船舶距航标的安全距离随着他船长度的增大而增加,分别为50m,70m,110m,150m。     

Hydrogeochemical processes identification and groundwater pollution causes analysis in the northern Ordos Cretaceous Basin,China

It is necessary to identify the hydrogeochemical processes and analyze the causes of groundwater pollution due to the lack of knowledge about the groundwater chemical characteristics and the endemic diseases caused by groundwater pollution in the northern Ordos Cretaceous Basin. In this paper, groundwater chemical facies were obtained using the piper trilinear diagram based on the analysis of 190 samples. The hydrogeochemical processes were identified using ionic ratio coefficient, such as leaching, evaporation and condensation. The causes and sources of groundwater pollution were analyzed by correspondence analysis, and the spatial distribution and enrichment reasons of fluoride ion were analyzed considering the endemic fluorosis emphatically. The results show that leaching, evaporation and condensation, mixing, and anthropogenic activities all had significant impact on hydrogeochemical processes in the study area. However, cation exchange and adsorption effects were strong in the S2 and S3 groundwater flow systems, but weak in S1. Groundwater is mainly polluted by Mn and COD_Mn in the study area. The landfill leachate, domestic sewage, and other organic pollutants, excessive use of pesticides and fertilizers in agriculture, and pyrite oxidation from long-term and large-scale exploitation of coal are the sources of groundwater pollution. The S1 has the highest degree of groundwater pollution, followed by S2 and S3. High concentration of fluoride ion is mainly distributed in the north and west of study area. Evaporation and condensation and groundwater chemistry component are the most important causes of fluoride ion enrichment. The results obtained in this study will be useful for understanding the groundwater quality for effective management and utilization of groundwater resources and assurance of drinking water safety.     

Tolerance of the black soldier fly,Hermetia illucens (Diptera: Stratiomyidae) to pH value,pungency, and NaCl in foodstuffs北大核心CSCD

The black soldier fly (BSF), Hermetia illucens, has been considered impressive as a saprophagous insect, for its high ability to convert organic waste to insect protein and oil. Hence, it has been regarded by the municipal administration that BSF might be used as a medium to deal with food waste. However, food waste in China has been characterized as having a high salt content, oily, and very spicy, which usually renders them unsuitable for animal feeding. In order to assess the technological reliability for BSF conversion of food waste, the tolerance of BSF for pH values, pungency, and NaCl in food were investigated in this case. Results indicated that strong acidity (pH = 3) was not good for the development of BSF, demonstrating less body weight and eclosion failure. In contrast, strong basicity (pH = 11) seemed to be beneficial for larval development with high biomass, and there is no difference in pupation, eclosion, larval biomass, and livability for BSF for pH values between 5 and 11. With regards to salinity, liner correlations were observed; the salinity strength increased along with the extension of the larval phase, but body weight, pupation rate, emerging rate, and livability were still consistent under 6% density of salinity. Influence of pungency on BSF larvae has not yet been found. In conclusion, BSF showed a high tolerance to pH value, pungency, and salinity in foodstuffs. Hence, it is expected that food waste from common environments might have a lesser possibility to cause negative effects on BSF development, which could be good news for BSF conversion technology. As for the process design, the conclusion suggested that food waste optimum for BSF is expected to be alkaline and low-salt, which would be helpful to improve the efficiency and harvest. © 2018 Science Press. All rights reserved.     

沈阳市大气PM2.5中水溶性离子的季节变化特征

为研究沈阳市大气中PM2.5及其水溶性离子的污染特征、季节差异和来源情况,使用URG-9000D在线监测系统对沈阳市2019年大气颗粒物进行连续的采样分析,并利用正交矩阵因子分析法(PMF)进行污染物的来源解析.结果 表明,2019年沈阳市秋冬季节PM2.5质量浓度变化受相对湿度影响较大,冬季PM2.5平均质量浓度达到85.76 μg·m-3,细粒子污染较为严重.沈阳市大气PM2.5中SNA(SO42-、NO3和NH4+)所占比重表现为春季最高秋季最低;夏季SO42-和NH4+浓度较高,而NO3-浓度较低.SO42-在夏季呈单峰型日变化,与NO3-变化趋势相反.春夏秋三季NH4+与SO42-、NO3-主要结合为(NH4)2SO4和NH4NO3,冬季NH4+主要以(NH4)2SO4和NH4HSO4的形式存在.沈阳市存在较强的SO2和NOx二次转化现象,且各季节中SO2的转化率均高于NO2.PMF源解析结果表明,二次源对沈阳市大气污染贡献最大,夏秋季生物质燃烧和冬季燃煤源贡献同样不可忽视.     

某金属冶炼企业土壤As污染特征及潜在生态风险评价

以某金属冶炼企业原址用地土壤为研究对象,采用单因子污染指数法、地累积指数法、潜在生态危害指数法探讨土壤As污染累积、潜在生态风险和空间分布特征。结果表明：研究区土壤采样点位超标率为98.85%,2.5~14.0 m深度范围土壤As污染较重、潜在生态风险较高,尤以6.0~10.0 m深度范围内相对最高。从As污染成因看,0~1.0 m深度范围土壤As污染主要受企业生产活动影响;1.0~14.0 m深度范围土壤As污染除受企业生产活动影响外,还与大量回填的含As较高的硫铁矿渣、极强碱性土壤环境、土壤渗透性有关。从As污染空间分布特征看,垂直方向上As污染浓度在0~10.0 m深度范围内随深度增加呈升高趋势,地表10.0 m以下随深度增加呈下降趋势。水平方向上,地表以下5.0、10.0、12.0 m剖面深度处As污染羽分布随深度增加呈增大趋势,12.0 m以下呈减小趋势。土壤As污染分层评价结果与地表以下特定剖面深度处土壤As污染评价结果一致性较好,土壤As污染较重的区域潜在生态风险亦相对较高。可见,采用单因子污染指数法、地累积指数法、潜在生态危害指数法综合评价土壤As污染与潜在生态风险,具有较高的可靠性。     

基于YanMeng台风风场的输电线路极值风速推算方法

极值风速作为输电线路抗风设计的重要参数,对结构的强度和年限标准意义重大。为克服采用观测资料直接推算极值风速的缺陷,给出了一种沿海地区输电线路极值风速推算的数值方法,即以台风风场物理方程为基础,利用历史台风进行反演,验证风场模型的适应性,随后结合台风年鉴,采用模拟圆和Monte Carlo抽样模拟进行研究点最大风速序列计算,并根据极值III型Weibull分布进行极值风速的推算。最后以海口市为例,对该极值风速推算方法进行详细阐述,推算了海口市近100a内重现期的极值风速,并与观测统计值进行对比,研究发现本文模拟效果较好,可以作为沿海地区输电线路抗风设计的理论参照。     

近3年西双版纳州勐腊县大气污染基本特征及污染原因分析

对西双版纳州生态环境局勐腊分局2017年8月-2020年8月逐日空气质量数据的分析表明,2-4月是勐腊县空气质量指数（Air Quality Index,AQI）频繁达到二级及以上的时段,空气质量分指数（Individual Air Quality Index,IAQI）能够达到二级及以上标准的污染物为PM_2.5、PM₁₀、O₃、SO₂中的一种或几种,PM_2.5、PM₁₀污染较为严重,PM_2.5对空气质量的影响最大,可使空气质量达到重度污染,混合污染出现比例远大于单一污染.2019、2020年3-4月勐腊县轻度及以上连续污染日数超过5 d的5次过程中,4次污染过程的主要潜在源区在勐腊上风方向老挝西北部及泰国与其相邻的区域,权重潜在源贡献因子（Weight Potential Source Contribution Function,WPSCF）大于0.6的区域与同年3、4月泰国西北部、老挝西北部的火点密集区有较好的对应关系,4次污染过程与老挝西北部及泰国与其相邻区域的生物质燃烧关系密切;1次污染过程的主要潜在源区主要在当地,当地建筑施工、交通运输、生物质燃烧和餐饮行业细颗粒物的排放会导致勐腊县空气质量出现明显下降.为验证勐腊县连续污染过程受到了周边国家烧荒的影响,利用逐日气溶胶光学厚度（Aerosol Optical Thickness,AOT）对2020年3月23-4月9日的污染过程进行了个例分析,发现AOT大值区位于勐腊上风方向,高浓度污染物持续稳定地向勐腊传输导致勐腊出现持续重污染.     

基于NPP-VIIRS夜间灯光的长株潭地区县域土地利用碳排放空间分异研究

从县域尺度开展土地利用碳排放空间分异研究,对指导区域实现碳达峰及碳中和目标具有重要意义.基于2013—2019年NPP-VIIRS夜间灯光数据测算长株潭地区县域土地利用碳排放,并运用探索性空间数据分析和地理探测器,对长株潭地区县域土地利用碳排放空间分异特征及影响因素进行分析.结果显示：①2013—2019年,长株潭地区县域土地利用碳排放差异较为显著,基本上在波动中呈递减趋势,空间上呈现自中部地区向四周地区渐弱的态势;②2013—2019年,研究区土地利用碳排放Moran''s I值呈"上升下降再上升"的趋势,由2013年的0.275841最终减少为2019年的0.270621,空间集聚特征较为显著,总体呈正相关;局部空间自相关均未出现高低、低低集聚型区域,且高高集聚型区域固定为湘潭市市辖区;③综合4年指标探测结果来看,长株潭地区县域土地利用碳排放影响因素的解释力q值为0.200~0.868.其中,单位能源消耗碳排放、第一产业产值比重、人均土地面积、土地利用程度指数、城镇化率在研究期间出现频率较高且出现时的q值均大于0.50,且任意两个影响因素交互作用后影响力表现为双因子增强和非线性增强.     

香溪河流域水生态系统健康评价

随着人们环境保护意识的增强,河湖生态保护与修复成为社会关注的热点问题,科学的生态健康诊断则是有效进行河湖治理的前提.香溪河作为三峡水库典型支流,探究其水生态系统健康对于长江生态保护具有十分重要的意义.通过收集整理香溪河干支流的生物与生境数据,构建了涵盖水环境、水生生物、物理栖息地三方面共16项指标的水生态系统健康评价指标体系,综合运用专家判断法和熵权法确定评价因子权重,采用河流健康指数（RHI）表征香溪河流域水生态系统健康状况.结果表明:①2017年三峡水库蓄水期香溪河流域水生态系统整体健康水平为良好,优和良等级占比分别为12.5%和79.2%.②健康状况呈现出支流优于干流、非回水区优于回水区的空间分布特点,具体表现为支流南阳河>支流古夫河>支流高岚河>香溪河干流.干流水环境问题相对突出,而支流的河流连通性相对较差.③库湾健康状况的年内变化特征为冬季最好,春秋季次之,夏季最差.研究显示,该评价体系能准确地评估香溪河流域水生态健康状况,同时需重视三峡水库支流库湾的水环境治理.