纤维素酶气相双动态固态发酵

为了充分利用纤维素酶固态发酵的优势,提出了纤维素酶气相双动态固态发酵的方式.研究结果表明:在优化条件下(最佳压力脉冲范围、脉冲频率及气体内循环速率),发酵温度得到较好地控制,9.0cm高的填料层中最大温度梯度为0.12℃/cm;以汽爆秸秆为底物,发酵水活度得到较好的保持;动态培养发酵周期(60h)比静态发酵周期(84h)缩短了 1/3,酶活(20.36IU/g)比静态酶活(10.82IU/g)提高了1倍,压力脉动固态培养的料层上中下微生物生长状况均匀一致,且疏松,而静态固态发酵的料层中部几乎没有菌体生长利用气相双动态固态发酵可为纤维素酶大规模生产奠定基础.     

钢筋混凝土结构抗火研究进展与趋势

火灾高温对钢筋混凝土结构材性有显著影响，极易造成结构损伤、破坏甚至倒塌。在大量阅读国内外文献的基础上，从建筑火灾发展过程研究、钢筋混凝土结构在火灾中的行为研究、钢筋混凝土结构抗火设计方法的研究、火灾后钢筋混凝土结构的损伤评估和加固方法的研究等4个方面对钢筋混凝土结构抗火研究进行了论述；总结了目前国内外钢筋混凝土结构抗火研究的主要进展及成果；指出了结构抗火研究尚存在的一些问题；最后，对结构抗火研究趋势进行了展望。     

三江源地区1961~2005年气温极端事件变化

利用三江源地区11个气象台站1961~2005年逐日最高气温和最低气温资料，分析了三江源地区极端高温和极端低温的变化趋势。研究表明：近45年来，白天和夜间温度极端偏高的日数明显增多，分别以26 d/10 a和44 d/10 a速度在增加;白天和夜间温度极端偏低的日数显著减缓，分别以41 d/10 a和85 d/10 a的速度显著减少;年极端低温和极端高温分别以042℃/10 a和029℃/10 a的速度增加;白天和夜间温度极端偏高的日数增加主要发生在冬季和夏季，而白天和夜间温度极端偏低的日数减少主要发生在春季和秋季，夜间温度极端偏低的日数减少趋势最为明显;长江源地区极端气温变化对区域增温的响应更为敏感。     

阿舍勒块状铜锌硫化物矿床矿物分带

本文对新疆阿舍勒块状铜锌碱化物矿体的内部构造及矿物共生组合进行了研究,与现代海底硫化物矿床的矿物分带作了比较,初步认为影响该矿床矿物分带的主要因素是成矿溶液的初始温度。     

Evidence of hydrocarbon contamination from the Burgan oil field, Kuwait: interpretations from thermal remote sensing data

The paper presents the application of thermal remote sensing for mapping hydrocarbon polluted sites. This has been achieved by mono-window algorithm for land surface temperature (LST) measurements, using multi-date band 6 data of Landsat Thematic Mapper (TM). The emissivity, transmittance and mean atmospheric temperature were used as critical factors to estimate LST. The changes in the surface emissivity due to oil pollution alter the apparent temperature, which was used as a recognition element to map out oil polluted surfaces. The LST contrast was successfully used to map spatial distribution of hydrocarbon pollution in the Burgan Oil field area of Kuwait. The methodology can be positively used to detect waste dumping, oil spills in oceans and ports, besides environmental management of oil pollution at or near the land surface.     

Spatio-temporal variations in water quality of Nullah Aik-tributary of the river Chenab, Pakistan

This study reports the spatio-temporal changes in water quality of Nullah Aik, tributary of the Chenab River, Pakistan. Stream water samples were collected at seven sampling sites on seasonal basis from September 2004 to April 2006 and were analyzed for 24 water quality parameters. Most significant parameters which contributed in spatio-temporal variations were assessed by statistical techniques such as Hierarchical Agglomerative Cluster Analysis (HACA), Factor Analysis/Principal Components Analysis (FA/PCA), and Discriminant Function Analysis (DFA). HACA identified three different classes of sites: Relatively Unimpaired, Impaired and Less Impaired Regions on the basis of similarity among different physicochemical characteristics and pollutant level between the sampling sites. DFA produced the best results for identification of main variables for temporal and spatial analysis and separated eight parameters (DO, hardness, sulphides, K, Fe, Pb, Cr and Zn) that accounted 89.7% of total variations of spatial analysis. Temporal analysis using DFA separated six parameters (E.C., TDS, salinity, hardness, chlorides and Pb) that showed more than 84.6% of total temporal variation. FA/PCA identified six significant factors (sources) which were responsible for major variations in water quality dataset of Nullah Aik. The results signify that parameters identified by statistical analyses were responsible for water quality change and suggest the possibility of industrial, municipal and agricultural runoff, parent rock material contamination. The results suggest dire need for proper management measures to restore the water quality of this tributary for a healthy and promising aquatic ecosystem and also highlights its importance for objective ecological policy and decision making process.     

Assessment of thermal stratification within stream pools as a mechanism to provide refugia for native trout in hot, arid rangelands

Native trout species, such as the redband trout (Oncorhynchus mykiss), occupy thermally harsh stream habitats in hot, arid rangeland basins of the western United States. Declines in the distribution and abundance of these species has generated interest in understanding how these cold water species survive in these systems, as well as in identifying opportunities to restore these species to their former ranges. The purpose of this study was to assess the potential for thermal stratification to provide thermal refuge for redband trout in stream pools characterized by warm intermittent flow conditions on arid rangelands. We studied vertical thermal stratification in two pools during three summers on Boles Creek located on the Modoc Plateau in extreme northeastern California. Water and air temperature data were collected on a 0.5 h time step from 15-Jun through 15-Sep during 1996, 1997, and 2000 using commercial temperature data-loggers. Water temperature was measured at the top (0.3 m below pool surface) and bottom (0.3 m above pool substrates) of each pool. Vertical thermal stratification occurred within these pools creating conditions as much as 7.6 ˚C cooler and consistently more constant at the bottom of pools compared to pool surface waters. Thermal stratification was dependent upon air temperature with the magnitude of stratification increasing as air temperature increased. The magnitude of thermal stratification varied significantly from year to year, likely reflecting variation in annual weather conditions. The thermal regime in the study pools was often near the upper lethal limit reported for redband trout, but temperatures at the bottom of these pools did offer refuge from lethal temperatures realized near the pool surface. Temperatures at pool bottom were consistently above optimal levels published for redbands.     

River use profile of the Central Niger Delta based on traditional eco-livelihood knowledge (TELK)

The Central Niger Delta is made up of a network of rivers and creeks that constitute the inland surface waters. These surface waters have historically influenced settlement patterns and are of diverse use to residents of the Central Niger Delta. Surface water like many ecological system are complex, whose complexity has been associated with seasonal variability. Traditional knowledge (TK), traditional ecological knowledge (TEK) and the traditional eco-livelihood knowledge (TELK) of residents of four rural communities in the Central Niger Delta have been explored in developing a river use profile of rural communities of the Central Niger Delta. A questionnaire survey has been carried out in four communities, two each from the Otuoke and Kolo Creeks. The result shows that river use varies across seasons and affected by: physico-chemical water quality and characteristics of surface water; the hydrological characteristics; the biological/ecological characteristics; cultural use and demand; need for development projects; and access to this vital resource. Fishing constitute one of the major livelihood source in the Central Niger Delta and the TELK of fishers in the sample communities have specifically been explored to understanding fishing patterns across seasons. The five seasons identified from this study are: flood season; flood recession season; dry season; early rainy season; and rainy season. Therefore, the thesis of this paper is that there is the need to balance the current usage of surface water in the developing world such as the Central Niger Delta with the demand for development as well as future use if development is to meet the criteria for equitable development. The river use profile could be a promising tool in planning for equitable development.