南极菲尔德斯半岛植被土壤N2O排放特征

应用密闭箱法首次测定了南极菲尔德斯半岛苔藓、地衣植被土壤N2O的排放通量,并估算了该半岛植被区土壤在夏季2个月内N₂O的排放总量.结果表明:在晴天和雨天,苔藓土壤N₂O的排放通量与温度有较好的响应关系,呈现单峰型变化趋势;但在雪天,与温度的变化不一致;苔藓、地衣这2种不同的植被土壤N2O排放通量日变化基本一致;温度是影响苔藓土壤N2O的排放通量季节变化的主要因子,同时还受降水的影响,干湿交替有利于N2O的排放;苔藓土壤N₂O的排放总量为3.7152kg;地衣土壤N₂O的排放总量为2.5344kg.由此可见,南极菲尔德斯半岛苔藓、地衣植被土壤N₂O排放量虽然很小,但仍起着大气N₂O源的作用.     

石油化工系统污泥处理研究

石油化工系统污水处理产生的污泥同城市污水处理产生的污泥有一定区别,针对兰州石化公司炼油化工污泥其固有的组分特点,并通过转筒离心机、板框压缩机、带式压滤机、真空过滤机等不同机械脱水方式的比较,提出了这类污泥在处理和处置时应注意的问题及几点建议。     

Timing crisis information release via television

When and how often to release information on television are important issues in crisis and emergency risk communication. There is a lot of crisis information, including warnings and news, to which people should have access, but most of it is not significantly urgent to interrupt the broadcasting of television programmes. Hence, the right timing for the release of crisis information should be selected based on the importance of the crisis and any associated communication requirements. Using recursive methods, this paper builds an audience coverage model of crisis information release. Based on 2007 Household Using TV (HUT) data for Hefei City, China, the optimal combination of broadcasting sequence (with frequencies between one and eight times) is obtained using the implicit enumeration method. The developed model is applicable to effective transmission of crisis information, with the aim of reducing interference with the normal television transmission process and decreasing the psychological effect on audiences. The same model can be employed for other purposes, such as news coverage and weather and road information.     

叠层橡胶支座串联隔震体系抗火性能研究

对叠层橡胶隔震支座在高温作用下的温度场进行数值模拟,利用小模型试件进行温度传导及温度场分布试验。在叠层橡胶隔震支座经历420℃的高温作用后,将隔震支座模型试件与钢筋混凝土柱串联,并对串联隔震体系的力学性能进行压剪往复试验。结果表明,叠层橡胶隔震支座在高温作用下的性能退化相当明显,承载状态下的橡胶隔震支座在稍高的温度作用下就开始发生畸变。这表明在实际工程中对叠层橡胶隔震支座采取防火保护措施对保证隔震结构承载力安全非常重要。     

基于复模态法的风电塔架体系地震反应分析

以往对风电塔架研究大多采用刚性地基的假定,忽略土—结构的动力相互作用。然而风电塔架在实际地震时,由于地基的柔性和无限性,使得按刚性地基假定计算出来的结构动力特性和动力反应与将地基和结构作为一个整体计算出来的结果有较大差别。因此,考虑土—结构相互动力作用(SSI)的风电塔架地震响应分析研究十分必要。以华能阜新风力发电塔架为例,基于复模态法分析考虑土—结构相互作用风电塔架地震响应,首先建立土—风电塔架体系计算模型,采用Novak模型对伐板的复刚度、复阻尼计算,然后建立土—风电塔架相互作用体系的地震反应方程,采用复模态分析方法对结构地震反应求解,可供风电塔架抗震设计参考。     

砷胁迫下水磷耦合对不同磷效率水稻根表铁膜及其各部位砷含量的影响

为探索缓解水稻砷毒害的农艺措施,以耐低磷水稻99011和低磷敏感水稻99012为材料,通过土培试验,研究水分、磷用量及其交互作用对不同砷浓度酸性土壤中水稻根表铁膜以及植物体内砷分配的影响。结果表明,节水灌溉(干湿交替)明显减少水稻根表铁膜量,降低铁膜、根系、秸秆、颖壳和精米中的砷含量。与30mg·kg-1P2O5相比,180mg·kg-1P2O5能明显减少两个品种水稻的根表铁膜量以及根系和秸秆中的砷含量;对耐低磷品种铁膜砷含量影响不大,但显著降低磷敏感品种铁膜砷含量;在50mg·kg-1砷处理中增加磷用量对水稻颖壳砷含量影响不大,在100mg·kg-1砷处理时能显著降低颖壳砷含量;增加磷用量可明显增加耐低磷品种的精米砷含量,降低磷敏感品种的精米砷含量。水、磷交互效应主要受水分效应的影响。加砷处理后,相同处理下耐低磷品种的根表铁膜量和铁膜中的砷含量显著高于磷敏感品种,而根系、秸秆、颖壳和精米中的砷含量则相反。研究表明,可以通过节水灌溉,并根据砷污染程度和植物磷营养特性确定适当的磷肥用量,从而减少砷在水稻体内的累积,提高食品安全。     

藻菌系统对偶氮染料降解作用的研究

研究了藻菌系统对偶氮染料降解的可能性,机理和环境条件的影响,49种不同类型的偶氮染料降解试验表明,藻菌对染料有较好的降解作用.发现藻类也能直接参与染料的降解,动摇了藻类在稳定塘有机物降解过程中仅能为好氧菌供氧的传统观念.根据典型染料实验研究表明,该系统降解偶氮染料的机理是:染料先被藻菌降解成芳香胺.尔后芳香胺在有氧条件下进一步降解成无机物;在无氧条件下,芳香胺降解受阻。环境条件试验表明,在相当广的pH值、温度、光强和碳源营养水平条件下,该系统仍有较高的降解效果。      

生物膜法A/O系统处理腈纶废水工业试验

本工业试验规模为１４００—１６００ｔ／ｄ,装置Ａ／Ｏ容积比１：３,当平均停留时间２２．６ｈ,回流比３．２,水温约３５℃左右时,平均去除率ＣＯＤｃｒ达８８．３６％、ＢＯＤ５９７．４９％、ＴＮ７７．６７％、ＡＮ９９．４１％。出水各项指标平均值为ＣＯＤＣｒ５３．５７ｍｇ／Ｌ、ＢＯＤ５５．６ｍｇ／Ｌ、ＴＮ１４．９４ｍｇ／Ｌ、ＮＨ３－Ｎ６．９２ｍｇ／Ｌ、ＡＮ１．０２ｍｇ／Ｌ、ＮａＳＣＮ２．６７ｍｇ／Ｌ,ＳＳ仅２０ｍｇ／Ｌ,因此不设二沉池。     

稠油热采污水回用锅炉给水处理工艺研究

采用生物接触氧化-超滤-反渗透集成工艺处理稠油热采污水,出水作为试验区稠油注蒸汽热采高压锅炉给水。运行结果表明:出水各项指标均达到试验区注汽锅炉给水水质要求,实现了稠油污水的资源化循环利用。     

Simulating dynamics of managed monsoon evergreen broad-leaved forest in south China

The forest succession model FORDYN is developed based on TREEDEV model. TREEDEV is a process-based tree growth model, that calculates tree growth based on carbon and nitrogen balance, and is calculated using on the photo-production of leaves, respiration, nitrogen content of all organisms and that in soil, and other losses due to respiration, litter and renewal of stems, branches, leaves and roots. In the FORDYN model succession is divided into three phases called early, middle and late succession, and the transition between these three succession phases is distinguished by a difference in leaf area index. As a verification of the model we used the characteristics and available data of a monsoon evergreen broad-leaved forest in Dinghushan Biosphere Reserve (DHS-BR). The model was validated with natural forest data. In addition, a sensitivity analysis was performed in which 30 independent variables were varied and analyzed in connection with their influence on 16 dependent variables describing forest conditions. The simulation results describe the changes in total biomass, carbon and nitrogen change in plant–litter–soil system of an undisturbed monsoon evergreen broad-leaved forest during succession. We compared these findings with simulation in which different logging management strategies were used. The results show that having a longer logging cycle, delaying the first logging time and a smaller logging fraction the scenario can contribute to a sustainable forest development, while still having a positive economic yield.