三峡库区航道疏浚泥沙悬浮扩散影响数值模拟研究

在利用FLUENT软件建立三维输移扩散模型的基础上,针对不同疏浚期,构建了汛期疏浚、旱期疏浚两种施工方案下的三维数学模型;对不同施工方案下的泥沙悬浮扩散范围及浓度分布进行模拟预测,得出了2种方案下泥沙悬浮扩散规律;对各种施工方案下对施工区域水体环境的影响进行分析比较,发现旱期疏浚对水体环境的整体影响小于汛期疏浚。     

沉水植物对沉积物微生物群落结构影响:以洪泽湖湿地为例

应用磷脂脂肪酸(PLFA)方法分析洪泽湖湿地典型沉水植物菹草群丛、蓖齿眼子菜群丛、菹-蓖混丛对其根系沉积物微生物群落结构的影响,以期了解沉水植物种类以及在不同生长时期对沉积物微生物群落结构的影响规律.结果表明,植物群丛根系沉积物PLFA总量在不同的时期发生了明显的变化,而同一时期的不同群丛PLFA总量差异不显著.沉积物微生物群落结构受沉水植物根系影响,菹草群丛中G~+/G~-(革兰氏阳性菌/革兰氏阴性菌)在3个不同生长时期比值为0.74、1.35、1.26,蓖齿眼子菜群丛G~+/G~-比值为0.89、0.98、1.49,菹-蓖混合群丛G~+/G~-比值为0.95、1.39、1.35,其G~+/G~-的变化和植物根系生长有密切关系.沉积物微生物群落结构受环境因子的影响,环境因子如T、p H、TOC、DO等与沉积物PLFA中特征磷脂存在相关性.     

哈尔滨市AQI与空气污染物的相关分析研究

空气质量问题已成为民众关注的热点问题.选取哈尔滨市2014年-2015年AQI日报数据,分别分析了供暖期和非供暖期PM2.5、PM10、CO、SO2、NO2、O3六种主要空气污染物与AQI的相关性,结果表明,AQI与6个主要污染物间呈显著性相关.同时建立了供暖期和非供暖期AQI与主要空气污染物的多元线性回归模型,结果表明,CO对AQI起着主要作用.因此,提高供暖过程中煤炭燃烧效率,可有效削减空气中CO的浓度,对于改善空气质量起着至关重要的作用.     

北京城区冬季空气污染时期C2~C6碳氢化合物含量特征

本研究于2015年冬季,在北京市东南城区开展了C2~C6碳氢化合物大气环境浓度在线监测,研究共检出25种C2~C6碳氢化合物,但鉴于分析仪器的局限性,未包含苯这一重要物种.检出的25种碳氢化合物含量之和(C2~C6 HCs)在12.4~297.5×10~(-9)范围内,不同的空气质量条件下,C2~C6 HCs平均含量分别为29.4×10~(-9)(Ⅰ级,PM_(2.5):35μg·m~(-3))、63.2×10~(-9)(Ⅱ级,PM_(2.5):35~75μg·m~(-3))、85.5×10~(-9)(Ⅲ级,PM_(2.5):75~150μg·m~(-3))、94.9×10~(-9)(Ⅳ级,PM_(2.5):150~250μg·m~(-3))、131.8×10~(-9)(Ⅴ级,PM_(2.5):250μg·m~(-3)),且碳氢化合物的化学组成亦有所差异,烷烃、烯烃、乙炔的摩尔比分别从Ⅰ级条件的47%、45%、7%,变为Ⅴ级条件的59%、30%、12%,烷烃和乙炔的比重上升;烯烃的比重下降.碳氢化合物日变化规律显示,C2~C6 HCs在优良日(PM_(2.5)小时浓度均低于75μg·m~(-3))和污染日(PM_(2.5)小时浓度均高于75μg·m~(-3)),均在08:00~09:00、17:00~18:00存在两个明显的峰值,与日交通峰值时间一致,显示了道路源对局地碳氢化合物浓度的显著影响.通过HCs与CO浓度比值研究,发现随着污染情况的加重,HCs/CO(×10~(-9)/×10~(-6))呈显著下降趋势:90.6(Ⅰ级)、63.8(Ⅱ级)、56.9(Ⅲ级)、37.4(Ⅳ级)、36.4(Ⅴ级).具体化合物与CO比值在污染条件(Ⅲ~Ⅴ)与优良条件(Ⅰ~Ⅱ)的变化率,与各化合物的OH反应速率关联性很差(R=-0.31),由此判断污染时期C2~C6碳氢化合物并未发生强烈的化学衰减.HCs/CO比值变化更多反映了污染源贡献的变化,后向轨迹分析表明,在优良日北京城区多受北部和西北部清洁气团影响,北部地区燃烧源较少,其气团HCs/CO比值较高;而在污染日北京城区受南部和西南部污染气团输送,南部地区工业燃烧源和散煤燃烧源均偏多,其气团HCs/CO值偏低.综上所述,本研究认为重污染过程,北京城区C2~C6碳氢化合物(未包含苯)未体现出显著的化学衰减,碳氢化合物浓度的大幅提升,不仅源于本地污染源的排放累积,还受到南部污染气团的输送贡献.     

Contribution of different sectors to developed countries’ fulfillment of GHG emission reduction targets under the first commitment period of the Kyoto Protocol

Greenhouse gas (GHG) data submitted in April 2014 on land use, land use change and forestry (LULUCF), energy, industrial processes, solvents and other product use, agriculture, and waste for 37 developed countries was analyzed to estimate the relative contributions of different sectors to GHG emission reductions. This GHG data from the first commitment period of the Kyoto Protocol included 35 parties to Annex B of the Kyoto Protocol, the United States and Canada. Results show that the contribution of each sector was, in order: energy (36.9%), industrial processes (12.4%), agriculture (9.9%), LULUCF (7.7%), waste (3.4%), and solvents and other product use (0.1%). The average proportion of base year emissions reduced in each sector by countries in Annex B was, in order: energy (7.4%), agriculture (2.7%), LULUCF (1.9%), industrial processes (1.2%), waste (0.5%), and solvents and other product use (0.1%). Overall, the energy sector contributed the highest GHG emission reductions, while the agriculture and LULUCF sectors also made contributions. Most countries achieved limited absolute GHG reductions from their chosen LULUCF activities, but the relative contribution of GHG emission reductions from LULUCF was significant but small. This suggests that, unless there are substantial changes to accounting rules, future emission reductions will mainly result from mitigation actions targeting fossil fuel consumption, while the agriculture and LULUCF sectors will continue to play auxiliary roles.     

“九五”长江沿江经济带发展前景研究

分析了长江沿江经济带经济发展的客观现状，明确了未来发展的目标，并就“九五”期间长江沿江经济带发展应注意的问题及相应对策进行了探讨。     

泰州市能源发展“十一五”规划环评研究

通过对泰州市能源发展“十一五”规划环评进行研究，着重分析了规划实施中对环境资源的消耗。根据当地环境资源的支撑能力，明确提出了调整能源结构等切实可行的应对措施及环境影响的减缓措施，通过采取一系列环境影响减缓措施，力求把区域经济建设等发展规模，控制在生态环境容量许可范围内。     

基于FMEA和模糊理论的海底管道建造期质量风险分析

为有效控制海底管道建造期间质量风险,采用基于模糊理论的故障模式及影响分析(FMEA)法分析海底管道在此期间众多的质量风险因素。该方法是在传统FMEA方法基础上,结合专家经验和知识确定模糊语言术语集和模糊数,对各风险因素进行模糊评价,根据各风险因素的模糊风险优先度数值(FRPN)进行风险排序,确定涂敷涂层期间需重点关注的风险因素。结果表明:涂层耐阴极剥离、管道腐蚀余量、混凝土抗压强度、密度、涂层张力等性能不满足设计要求是海底管道在涂敷涂层期间质量控制的关键因素。     

Relationship between near-surface morphological traits of familiar plants and their ability for sediment retention in a dry-hot valley北大核心CSCD

To explore the sediment interception capacity of plants and its relationship with the surface morphological traits of plants, we used laboratory simulations and off-site flume experiments to study the ability for sediment retention of six familiar species: Leucaena leucocephala (LL), Melia azedarach (MA), Dodonaea viscosa (DV), Coriaria sinica (CS), Heteropogon contortus (HC), and Eulaliopsis binata (EB) aver two growth periods in the dry-hot river valley of the Jinsha River. We analyzed the relationship between near-surface morphological traits of individuals of six species and their ability for sediment retention. Our study resulted in three main observations. (1) In the flume experiment, three-month seedlings and one-year old seedlings of the six species showed different abilities for sediment retention. In the three-month seedlings, the ability for sediment retention of CS was the highest, followed by MA and LL, whereas it was the lowest in HC and EB. However, in one-year old seedlings, the ability for sediment retention of CS was the highest, but the ability for sediment retention of HC and EB was better than those of MA and LL. Hence, the ability for sediment retention of the six species fluctuated between different growth periods. (2) The three-month old and one-year old seedlings of all six species showed different near-surface morphological traits. (3) The sediment mass was significantly and positively correlated with near-surface leaf areas, crown lengths, crown widths, stem dry matter densities at the intersection volume, and above-ground biomass, but significantly and negatively correlated with the angle between stem and ground, indicating that these latter are the main near-surface morphological traits able to affect sediment retention. In addition, the sediment mass was also correlated (positively and negatively) with the stem epidermal crack number, stem dry matter content, leaf dry matter content at the intersection volume, and dry mass per unit volume of the intersection volume, which could also reflect the ability of sediment retention. We conclude that in the areas where plant measures are used to control soil erosion and intercept sediment, the key, above-mentioned plant morphological factors should be taken into account in order to select the optimal plant species. © 2018 Science Press. All rights reserved.     

新时期高校实验室安全管理的分析与思考

高校实验室是进行实验教学和开展科学研究的重要基地,是理论联系实际,人才培养和科技创新的必备场所。实验室的安全对高校乃至全社会的安全和稳定都至关重要。笔者分析了新时期高校实验室安全管理的现状、特点以及存在的问题;对高校实验室的安全、环保管理发表了自己的见解,提出了“以人为本”、“安全第一,预防为主”,“依法整治”的观点,它是建设和管理高校实验室的基本思路,也是实现高校实验室安全的基本原则;同时调强了保护教师和学生的实验室安全与健康,不仅仅是实验室的安全问题,也是校园安全管理工作的重要组成部分。