The Holocene Dynamics of Vegetation and Ecological Conditions in the Polar Urals

Palynological, paleocarpological, and paleoentomological analyses of frozen peat deposits near Lake Pereval'noe, the Polar Urals, were performed to reveal the main stages of change in the pattern of vegetation over the period from the beginning of warming after the last Pleistocene glaciation to the late Holocene. Nine to four thousand years ago, the study region (at the present-day upper boundary of open larch forests) was covered with taiga forests, as the climate there was significantly warmer. These were larch–birch forests with an admixture of spruce and, later, spruce forests with larch and birch.     

北部污水处理厂污泥消化系统大修技术措施探讨

消化系统是污水处理厂污泥处理中的核心工艺环节,其运行效率及运行安全性直接影响污泥处理效果。结合北部污水处理厂消化池的运行管理及大修工作,总结经验,为消化系统稳定运行提供借鉴。     

大亚湾大鹏澳海域C、N、BSi的沉积记录研究

研究了大亚湾大鹏澳海域鱼类养殖区、贝类养殖区以及核电站附近3个站位50~78 cm的柱状沉积物中生物硅(BSi)、总有机碳(TOC)、总氮(TN)等生源要素的垂直变化,以揭示人类活动对海洋环境影响的沉积记录。位于近岸海水养殖区的两个沉积柱中,近年来TOC含量呈明显上升趋势,而核电站附近海域略有下降。从TOC/TN比值判断(三个沉积柱平均分别为9.54、7.42、7.9),该海域TOC是陆源和水生两种来源的混合物。此外,养殖区上表层沉积物中水生有机碳(TOCa)含量呈明显下降趋势,而TOC/TN比值则上升,说明养殖区水生初级生产力及其对总初级生产力的贡献下降;相反,陆源污染所造成的陆源有机碳(TOCt)含量明显增加。在核电站附近海域,TOCa含量明显上升,TOC/TN和TOCt值下降,表明核电站的运行使水体初级生产力上升,陆源有机碳输入则减少。BSi、BSi/TOCa的垂直分布表明,海水养殖区硅藻对总初级生产力的贡献逐年上升,而核电站海域硅藻的贡献则下降。     

模糊层次综合评判法在火电厂选址决策中的应用

根据影响火电厂选址的因素较多、相互之间具有不确定性和模糊性这一特点,结合火电厂选址的实际情况,建立了火电厂选址综合效益评价指标体系;运用模糊层次综合评判法确定了各指标的权重分配;从可持续发展的角度对火电厂选址综合效益进行了评价;经过专家投票,将各因素层次化,得出模糊评价结果,即找到综合效益最好的厂址;并通过实例验证了该方法的可行性。可为火电厂决策者投资建设项目提供依据。     

复合材料补片胶接修补剥蚀金属结构技术研究

建立了复合材料补片单面胶接修理含孔剥蚀损伤铝合金试件的三维有限元模型,分析了修理结构的应力分布情况,对中性轴偏离导致的弯曲变形及固化过程中形成的残余热应力对修理效果的影响进行了评估。结果表明,复合材料补片单面胶接修理是一种有效的修理方法,复合材料补片可以对含孔剥蚀损伤铝合金试件补强。     

郑州市五龙口污水处理厂运行分析

五龙口污水处理厂工程设计规模10万m3/d,污水二级生化处理采用改良氧化沟工艺。依据水质的特点,确定污水处理工艺及构筑物设计。运行结果表明,污水处理厂运行稳定,污染物去除率高,达排放标准。     

Effects of vegetable oil residue after soil extraction on physical-chemical properties of sandy soil and plant growth

Vegetable oil has the ability to extract polycyclic aromatic hydrocarbons(PAHs)from contaminated sandy soil for a remediation purpose,with some of the oil remaining in the soil.Although most of the PAHs were removed,the risk of residue oil in the soil was not known.The objective of this study was to evaluate the effects of the vegetable oil residue on higher plant growth and sandy soil properties after soil extraction for a better understanding of the soil remediation.Addition of sunflower oil and column ex...     

Influence of environment and substrate quality on the decomposition of wetland plant root in the Sanjiang Plain, Northeast China

The litterbag method was used to study the decomposition of wetland plant root in three wetlands along a water level gradient in the Sanjiang Plain,Northeast China.These wetlands are Calamagrostis angustifolia(C.aa),Carex meyeriana(C.ma)and Carex lasiocarpa (C.la).The objective of our study is to evaluate the influence of environment and substrate quality on decomposition rates in the three wetlands.Calico material was used as a standard substrate to evaluate environmental influences.Roots native to each we...     

流动电流沿水厂工艺的变化研究

在水厂现场,以流动电流为主线对净水工艺进行了分析。结果显示,流动电流对混凝和滤床过滤的运行工况有类似的决定作用,加药混合之后胶体颗粒的流动电流值不再随后续工艺而有大的变化,因此投加混凝剂保持混凝单元操作的最佳状况,也有利于过滤单元的运行。     

西安市污水厂污泥脱水试验

文章简要介绍了城市污水厂污泥的性质,并用不同的絮凝剂对城市污水污泥进行调质,结果表明阳离子型高分子絮凝剂能够取得较好的效果,并初步分析了絮凝剂的作用机理。对选定的药品进行生产性污泥脱水试验,结果使A2/O工艺的剩余污泥的平均含水率由97.4%降低至84.0%,普通活性污泥的平均含水率由93.2%降至70%。并分析了影响城市污泥脱水的因素及污泥脱水的成本分析。