利用模糊数学综合评价天然气管道的内腐蚀

通过对管道内腐蚀程度进行定量评价,了解管道的内腐蚀情况,是管道剩余强度评价、剩余寿命预测以及可靠性分析的基础.提出了利用模糊数学综合评价方法对天然气管道内腐蚀程度进行综合评价的具体方法,并通过应用实例验证了该评价方法的可行性.     

对凯氏定氮法测定食品中蛋白质含量的测量不确定度评定

通过对凯氏定氮法测定食品中蛋白质含量的测量不确定度分析,对其标定结果的质量进行了定量表征。结果表明,该食品中蛋白质的含量为25.88%±0.15%(k=2),测量结果重复性的不确定度对总体不确定度作用最大。     

细叶桉和尾叶桉种源试验研究

尾叶桉与细叶桉8个种源生长性状与保存率的差异和遗传分析结果表明；种源间除高径比外各性状的差异极显著，种源层次各性状遗传力为43.25％～88.14％，单株层次各性状遗传力为16．00％～65．01％；树高、胸径、材积等生长性状间呈紧密的正相关，保存率与生长性状的相关不显著。3、5年生时尾叶桉14532种源和细叶桉13541种源在各自的树种中生长最优，平均单株材积分别这0.09636m^2时0.04516m^3。经综合评价，细叶桉13541、13544和尾叶桉14532、14531为优良种源。估算了参试种源各个性状的育种值。     

桂东丘陵生态林业经营模式选择研究

根据桂东地区自然地貌和林业生产的特点，在苍梧县建立了4种生态林业复合模式类型20个经营模式，通过对这些经营模式的结构。功能和效益等方面的综合评价，筛选出了10个较佳的生态林业经营模式，并提出了配套的经营技术和适宜推广应用地域，为试验区的林业可持续发展和高效生态林业工和建设提供了科学依据和技术支撑。     

奶牛秸秆型日粮矿物质营养水平评价

对淄博地区奶牛营养两次调查过程中,发现秸杆型日粮饲喂的奶牛可能存在矿物质缺乏问题。针对这一问题,测定日粮中钙、磷、铜、锰、铁、锌和奶牛血液中铜、锰、铁、锌元素的浓度,用以评价秸杆型日粮奶牛矿物质营养水平。结果表明:①秸杆型日粮存在矿物质营养不平衡问题,锰、锌元素不足,铁元素过剩。②秸杆型日粮矿物质营养具有互补作用。③评价奶牛矿物质营养水平的手段有待改进。     

Spatial variation in forage nutrient concentrations and the distribution of Serengeti grazing ungulates

Resident grazing ungulates in the Serengeti National Park, Tanzania, are conspicuously patchy in their distribution among regions of the Park. Linear programming models that maximize nitrogen (N) consumption by foraging ungulates in Serengeti regions having high and low resident animal densities were compared using forage ingestion rate and twelve nutritional requirements as simultaneously imposed constraints on forage choice. Model results indicate that (1) growing season N or crude protein is not limiting in either region although greater N ingestion is possible within the eastern corridor under other nutritional constraints, (2) grazing ungulates in the eastern corridor region occur in greater density and are capable of balancing dietary requirements solely from forage while simultaneously consuming more protein than ungulates in the northeast region, and (3) rarer landscape elements are most capable of providing ungulate dietary requirements in both the northeast and eastern corridor. These results provide a nutritional basis to understand patchy spatial distributions of grazers within Serengeti regions and landscapes, and provide a partial test of the hypothesis that large generalist herbivores should graze rare forages more frequently. The ability of uncommon landscape elements to support ungulate grazing over the growing season is supported by previous ecosystem studies that demonstrate the capability of grass forages for compensatory growth and the ability of grazing to stimulate rapid nutrient recycling.     

Epidemiology theory and disturbance spread on landscapes

Abtract Epidemiology models, modified to include landscape pattern, are used to examine the relative importance of landscape geometry and disturbance dynamics in determining the spatial extent of a disturbance, such as a fire. The models indicate that, except for very small values for the probability of spread, a disturbance tends to propagate to all susceptible sites that can be reached. Therefore, spatial pattern, rather than disturbance dynamic, will ordinarily determine the total extent of a single disturbance event. The models also indicate that a single disturbance will seldom become endemic,i.e., always present on the landscape. However, increasing disturbance frequency can lead to a landscape in which the proportion of susceptible, disturbed, and recovering sites are relatively constant. Research supported by Ecological Research Division, Office of Health and Environmental Research, U.S. Department of Energy under contract No. DE-AC05-840R21400 with Martin Marietta Energy Systems, Inc. Contribution No. 10 to the Sevilleta LTER program. Environmental Sciences Division Publication No. 3812, ORNL.     

多年生黑麦草顶峰的引种适应性研究

国外引进优良草坪草种———多年生黑麦草顶峰 (Pinnacle) ,在国内的 3个气候带 :北京 (北过渡带 )、兰州 (寒冷半干旱带 )和成都 (南过渡带 )等地 ,进行了品种评定和适应性的研究 ,结果表明 :多年生黑麦草顶峰适宜在中国北方过渡带和南方夏季不甚高温高湿的地区推广 ,在兰州以西越冬不理想。     

阿拉尔片区部分豆制品卫生学评价

本实验是以阿拉尔片区部分豆制品卫生质量进行感观和细菌学评价,为消费者的健康饮食做以指导。结果显示:阿拉尔片区所售的部分豆制品存在着卫生质量问题,菌落总数不合格的为44%;大肠菌群数不合格的为25%;九团检样豆腐中检出一例蜡样芽胞杆菌,阿拉尔片区部分豆制品总体合格率占检样的56%。     

呼和浩特市城市现代化水平综合评价与分析

城市现代化是城市素质的综合反映,城市现代化水平评价是衡量1个城市综合竞争力的最有效方法。本文根据城市现代化的概念与内涵,构建了呼和浩特市城市现代化评价指标体系与测度模型,运用层次分析法对历年的城市现代化水平进行了综合评价与动态分析。分析表明:自1990年以来,呼和浩特市城市现代化水平呈平稳上升趋势,但总体水平仍然偏低,处于现代化的准备阶段向基本实现现代化阶段的过渡时期。