DEVELOPMENT OF AN INVERTEBRATE COMMUNITY INDEX FOR AN ALABAMA COASTAL PLAIN WATERSHED1

ABSTRACT: Activities such as agriculture, silviculture, and mining contribute nonpoint pollution to Alabama's streams through polluted runoff and excessive sedimentation. Highly erodible soils characteristic of the Choctawhatchee‐Pea Rivers watershed, combined with intense rainfall and land use practices, contribute large amounts of sediment to streams. Biological monitoring can reflect the acute impacts of pollutants as well as prolonged effects of habitat alteration, and development of biological criteria is important for the establishment of enforceable laws regarding nonpoint source pollution. Macroinvertebrates were collected from 49 randomly selected sites from first through sixth‐order streams in the Choctawhatchee‐Pea Rivers watershed and were identified to genus level. Thirty‐eight candidate metrics were examined, and an invertebrate community index (ICI) was calibrated by eliminating metrics that failed to separate impaired from unimpaired streams. Each site was scored with those metrics, and narrative scores were assigned based on ICI scores. Least impacted sites scored significantly lower than sites impacted by row crop agriculture, cattle, and urban land uses. Conditions in the watershed suggest that the entire area has experienced degradation through past and current land use practices. An initial validation of the index was performed and is described. Additional evaluations of the index are in progress.     

对化学品登记要求的数据解释：—理化参数和生物降解

本文对化学品登记时所要求的理化和生物降解数据做了解释。涉及到的测试参数包括:紫外—可见光谱、熔点、沸点,蒸汽压曲线、水溶解度、吸附—解吸、分配系数(正丁醇—水)、液体和固体密度、颗粒物粒度分布、与 pH 有关的水解作用、在水中的离解常数和快速生物降解。     

吹脱法处理高浓度氨氮废水的研究

通过对盘锦某催化剂厂在生产催化剂过程中产生的高浓度氨氮废水静态吹脱试验，总结出水温、pH、水力停留时间、气水比、1号脱氮剂用量等相关参数对吹脱效率的影响。     

Microscale Spatial Variation in Forest Litter Phytotoxicity

The spatial variation (within a 100 × 100 m plot) in the pollution of forest litter with heavy metals (Cu, Cd, Pb, and Zn), its acidity, and phytotoxicity (measured by the results of the root test using seedlings from a genetically homogeneous sample of common dandelion (Taraxacum officinale s.l.) have been estimated. Forest litter has been sampled in three zones differing in the toxic impact of long-term polymetal pollution by emissions from a copper-smelting plant emissions in the Middle Urals. The phytotoxicity variation is maximum in a moderately polluted plot, where both very high and very low pollution levels were observed, which determines a substantially nonlinear dose–effect relationship. The litter phytotoxicity is mainly accounted for by exchangeable forms of metals. Biological testing of samples from the most polluted plot has demonstrated marked antagonism between heavy metals and acidity.     

建设生物防火林带的重要意义

阐述了营造生物防火林带是阻隔林火蔓延、实现"绿色防火"的主要措施,对保障森林资源安全、减少森林灾害的损失将发挥积极作用.     

影响大型复杂机械钢结构系统可靠性的因素分析

以结构力学为理论依据,以有限单元法为基础,借助和参考有关有限元程序设计方法,按照结构系统可靠性失效模式分析的要求,采用编程语言研制成功基于有限元的可靠性分析软件RAPS(Reliability Analysis Program of Structure based on FEM),运用该软件对立体车库钢结构的可靠性进行具体的分析;对判定结构系统失效与否的失效准则进行讨论和分析,并针对立体车库钢结构,得出合理的失效准则和系统可靠度的计算方法;通过实例说明约界参数CAP、失效路径长度和系统复杂程度对失效准则和系统可靠度结果的影响。     

有机固体废物生物法制氢的研究进展

综述了利用有机固体废物生物法制氢的原理和研究现状。城市有机固体废物、农业有机废物、工业有机废物是生物法制氢的主要原料。暗发酵制氢是利用有机废物厌氧消化的产酸阶段而产氢，pH、温度、水力停留时间、氢气分压、原料性质、微量元素含量、产甲烷微生物抑制剂等均影响氢气产率。光发酵制氢是利用光合厌氧细菌将挥发性有机酸转化为氢气和二氧化碳。暗发酵和光发酵制氢时，生物固定化有利于高速连续产氢。在有机废物处理和生物法制氢方面，暗发酵一光发酵、暗发酵一微生物燃料电池的组合工艺是具有前景的技术。今后的研究方向是原料的预处理技术、选育高效产氢菌株、发明高效反应器、优化处理工艺和处理条件等。     

小波分析在语音识别系统中的研究与应用

在语音识别系统的不同处理阶段,大部分可以使用小波分析技术进行实现,并且这种实现方法比传统的方法具有更好的效果.本文重点探讨了在端点检测、噪声去除以及参数提取过程中使用小波分析技术的原理及方法,并提出现阶段所存在的问题及解决方案.     

胜利油田利用生化法处理含油泥砂研究

胜利油田含油泥砂中含油量较高,直接进行生物降解处理的难度较大,操作周期长,费用高。先采用化学方法处理再进行生物处理,这样既可实现原油的资源化,又可降低费用,提高处理速度及处理效果。实验结果表明:化学处理方法能够将含油泥沙的含油量由51.1%降低至3.1%,原油回收率达到94%以上;再经过48h的生物处理,其含油量降到0.18%,达到了国家规定的无害化排放标准(<0.3%)。