生物强化技术及其在水污染治理中的应用

随着工业化的不断发展,对于水体污染的问题越来越严重,水污染的治理是目前最为关注的话题。伴随着生物强化技术的诞生,可以保证解决水污染问题的有效性。本文首先对生物强化技术简介和来源进行了介绍,然后对生物强化技术治理水污染的作用进行了详细的阐述,最后对生物强化技术在水污染治理中的应用进行了总结分析。     

改良多介质土壤层系统对污染河水的脱氮效果

针对多介质土壤层系统（MSL）反硝化不足导致总氮去除效果不明显的问题,采用非水溶性可生物降解多聚物PBS固相碳源,优化MSL系统空间结构（下部空间结构由砖砌改为层铺）,研究改良MSL系统对污染河水的脱氮效果。结果表明,与木屑作碳源的MSL系统相比,PBS颗粒碳源反硝化效果更好,对TN的去除率达64．3％,提高20．6百分点;优化MSL系统下部空间后,TN去除率由43．7％提高至71．7％,且运行期间系统未出现堵塞情况。添加PBS颗粒碳源和优化系统空间结构,对COD、NH3-N和TP去除效果影响不大。     

井下穿层长钻孔水力压裂强化增透技术

为了提高井下低透气性煤层瓦斯抽采效果,提出井下穿层长钻孔水力压裂强化增透技术。根据水力压裂施工工艺和关键技术,将水力压裂过程分为准备阶段、高压注水阶段和保压阶段,重点阐述了封孔、试压、注水压裂、数据监测、保压、排水等关键技术。同时分析了长钻孔水力压裂增透机理,并进行了水力压裂强化增透试验。根据压裂过程中压裂参数变化规律,从煤储层参数和钻孔瓦斯抽采参数方面综合考察了试验效果。结果表明:压裂后煤层透气性系数提高了2.67倍,最大影响半径达到了58 m,抽采流量和抽采体积分数分别是普通压裂钻孔的24.4倍和10.27倍,最大压裂影响半径提高了2.32倍。     

Effects of herbage removal on productivity of selected high-sierra meadow community types

We investigated the effects of herbage removal on three subalpine meadow plant communities in the Rock Creek drainage of Sequoia National Park, California, USA. In the xericCarex exserta Mkze. (short-hair sedge) type, annual aboveground productivity averaged 19 g/m² in control plots (clipped once after plant senescence in late September) over a five-year period. Annual aboveground productivity was enhanced about 30%–35% when plots in this community type were clipped more frequently (i.e., additional herbage removal in the early, mid, and late seasons) during each of four treatment years but was reduced by 13%–19% during a fifth (recovery) year in which all but late September clipping was suspended. In a moderately mesicEleocharis pauciflora (Lightf.) Link. (few-flowered spike rush)-Calamagrostis breweri Thurb. (short-hair grass) type, control plot productivity averaged 115 g/m²/yr and was reduced by 20–30% by the additional herbage removal. A more mesicDeschampsia caespitosa (L.) Beauv. (tufted hairgrass)-Carex rostrata Stokes, (beaked sedge) type had the greatest mean above-ground productivity (169 g/m²/yr) but also showed damage (i.e., decrease in productivity by 15%–20%) caused by the additional herbage removal. These data suggest that longterm, intensive herbage removal may be more detrimental to moderately mesic and mesic subalpine meadow community types than to xeric types.     

基于ANSYS仿真的引信振动强化试验夹具设计

在引信振动强化试验中,对夹具的性能具有很高的要求。利用夹具设计理论对夹具所用材料、结构进行分析,并在有限元分析的基础上,利用ANSYS软件对所设计的引信夹具进行了模态分析,得出了夹具的固有频率,使之能够满足引信强化振动试验的要求。通过实验验证了仿真的有效性,从而为引信夹具的设计提供了一种新的方法。     

细水雾扑灭油池火过程中火焰强化现象的实验研究

在细水雾扑灭油池火的初期,某些油池火焰会有一个突然强化、剧烈燃烧的情况发生。通过实验研究证明,酒精等与水互溶的液体不会发生强化现象,汽油和柴油等不溶于水的液体则有明显的强化现象;同时,发生强化现象的根本原因是共沸使得细水雾到达燃料表面后急剧沸腾而强化燃烧。     

自然环境超高加速光老化试验系统研制

目的 设计一种能够高效强化太阳紫外光辐射强度的自然环境加速试验设备,在自然环境环境中,用于高分子材料及制品、零部件的耐光老化高加速试验与快速评估。方法 自然环境超高加速光老化试验系统研制主要采用模块化设计思路,基于3个太阳辐射强化原理,开展紫外反射镜开发,设计系统总体结构、试验主机、太阳能供电分系统和控制分系统等,对主机结构进行有限元强度和变形量分析,开发以PLC为核心的控制系统和以触摸屏及计算机为媒介的人机交互软件。结果 研制的自然环境超高加速光老化试验系统采用太阳能清洁能源供电,实现了40倍以上的太阳紫外辐射强化。结论 研制的自然环境超高加速光老化试验系统加工与制造难度小,加速倍率高,环境友好,使用效费比高,更适用于户外装备用高分子材料及制品的耐光老化评估。     

Pup production,sex ratios,and survivorship in African wild dogs, <Emphasis Type="Italic">Lycaon pictus</Emphasis>

The local resource enhancement (LRE) model predicts that in cooperatively breeding species, sex ratios will be biased in favor of the more helpful sex. In this study, we assess the assumptions underlying the LRE model in a population of cooperatively breeding wild dogs (Lycaon pictus) in Northern Botswana monitored over a 15-year period. In this population, litter size and pup survival to 1 year are strongly affected by pack size and the breeding female’s age, but adult males have a stronger and more linear effect on females’ reproductive performance than do adult females. This asymmetry in the benefits derived from male and female helpers is reflected in male-biased sex ratios in litters at the time pups emerge from the den. Sex ratio biases are most pronounced in the litters of the youngest mothers who live in significantly smaller packs than older females. The presence of potential rivals for the dominant female’s position depresses pup production at the time of emergence, suggesting that competition among females for breeding positions may also contribute to the selective forces affecting birth sex ratios.     

高瓦斯低透气性煤层深孔预裂爆破增透技术研究及应用*

为解决高瓦斯矿井开采过程中煤体透气性差、瓦斯预抽周期长、抽采效果不佳的难题,提出利用深孔预裂爆破技术提高煤体裂隙发育度,增加煤体透气性,从而提高瓦斯抽采率的方法。通过现场调研、理论分析、数值模拟及工业性试验等方法,分析深孔预裂爆破卸压增透内在机理,确定爆破影响半径为4.5~5.3 m,并在A110605工作面进行现场应用,同时考察煤层增透效果。研究结果表明:煤层爆破致裂后,平均瓦斯抽采浓度提高了2.17倍,平均瓦斯抽采纯量提高了2.02倍,煤层透气性系数提高了近5.3倍,煤层卸压增透效果显著,很大程度上消除了煤与瓦斯突出危险性,为实现工作面的安全开采及正常接替提供了保障。     

基于电动振动台的强化试验剖面参数计算与控制

在进行组件级产品振动试验时,传统试验方法存在产品的低阶振动模态激发能力较弱,试验结果重现性差,而采用低频特性优良的电动振动台及其控制仪进行应力加载则可克服RS机的缺陷.本文给出了基于电动振动台的随机振动试验剖面的数学描述,推导出应力量级和试验应力谱参数的解析关系,进而导出便于工程应用的剖面参数计算方法,并讨论了应力剖面的控制.最后在某导弹发射控制盒组件的振动强化试验中进行了应用,验证了该方法的有效性.