投影带变换对长度变形的影响

文章对晋城矿区由矿区独立坐标系改用部定3°带平面坐标系后引起的边长影响进行了分析和计算,提出了应采取的对策及相关注意事项。     

佛山市禅城区大气环境质量变化研究

以佛山市禅城区近20年的大气环境监测数据为依据,对NOx,SO2,降尘、总悬浮颗粒物(TSP)、酸雨等大气环境质量要素的变化进行分析。结果表明,禅城区大气环境质量20世纪90年代比20世纪80年代差,21世纪初有所好转,但近年来又有所变差,首要污染物从过去的尘粒性污染物转为现在的SO2。     

明清时期广东地区气候变冷对社会经济发展的影响

通过对比广东15世纪末至19世纪末即LIA期间的气象灾害、战乱、人口发展等几方面的数据,研究了明清时期气候变冷对广东地区社会经济发展的影响,发现这一时期农业生产的衰退、生态环境的恶化、战乱和农民起义的增多、人口发展的减缓以及瘟疫次数的增加,都与气候变冷有明显的相关性.同时指出,气候变冷的各个可能的影响结果之间,又有着密切的联系,它们相互影响,相互作用,严重阻碍了明清时期广东社会经济的正常发展.     

基于人工神经网络的遥感图像分类研究

随着人工神经网络系统理论的发展,神经网络技术日益成为遥感图像分类处理的有效手段,并有逐步取代最大似然法的趋势。本文重点讨论了遥感图像分类处理研究中应用效果显著的BP神经网络方法,并在MATLAB平台下对基于BP神经网络的分类算法进行了研究,最后将它的分类结果与最大似然法的分类结果进行了精度比较分析。结果表明基于BP神经网络的遥感图像分类效果是较好的,是一种有效的图像分类方法。     

Techniques of Image Processing Based on Artificial Neural Networks

This paper presented an online quality inspection system based on artificial neural networks. Chromatism classification and edge detection are two difficult problems in glass steel surface quality inspection. Two artificial neural networks were made and the two problems were solved. The one solved chromatism classification. Hue, saturation and their probability of three colors, whose appearing probabilities were maximum in color histogram, were selected as input parameters, and the number of output node could be adjusted with the change of requirement. The other solved edge detection. In this neutral network, edge detection of gray scale image was able to be tested with trained neural networks for a binary image. It prevent the difficulty that the number of needed training samples was too large if gray scale images were directly regarded as training samples. This system is able to be applied to not only glass steel fault inspection but also other product online quality inspection and classification.     

基于3S的土地利用时空特征研究——重庆市北部新区为例

在3S（GIS，RS，GPS）技术的支持下，通过建立数学模型对城市土地利用时空特征进行研究，并以重庆市北部新城为试验区域，对该区域土地利用类型、土地利用程度、城市扩展等时空特征进行了动态分析，取得了良好的效果，为定性定量研究区域土地利用、土地覆盖的时空演变提供了一种新思路和新方法。     

新疆塔里木河湿地保护和建设的研究

新疆塔里木河湿地是我国最长的内陆河流湿地,是多种鸟类栖息与多种候鸟迁徙中转、繁殖的重要区域.本文对塔里木河湿地的基本特征、生态功能、近代变化和其保护与建设的现实意义进行了研究,指出应该重视科学研究,拯救珍稀濒危物种,并提出了相应对策.     

21世纪吉林省农村居民消费结构变动趋势分析

从《吉林统计年鉴》的统计资料,了解到近3年吉林省农村居民的消费情况和消费结构的变动趋势。通过对消费结构变动趋势的分析,提出应从增加农民收入、改善农村消费环境、倡导个人信贷消费以及建立农村社会保障体系等方面采取积极有效的对策措施,来扩大吉林省农村居民消费。     

Climate change and hydrologic process response in the Tarim River Basin over the past 50 years

Climate change and hydrologic process response in the Tarim River Basin over the past 50 years are the focus of more and more researchers＇ attention. In this paper, both temperature and precipitation time series were found to present a monotonic increasing trend using nonparametric tests. Noticeably, a significant step change in both temperature and precipitation time series occurred in 1986. By contrasting the trends of natural water process in headstream and mainstream, we found that it was anthropogenic activities not climate change that caused the river dried up and vegetation degenerated in the lower reaches of Tarim River. The results of gray correlation analysis show that the runoff of higher latitude distributing river is more closely associated with winter snow stocking, while that of lower latitude is more closely related to summer temperature. Runoff in the headstream is more sensitive to precipitation, while that in the mainstream is more sensitive to evaporation. The strong evaporation caused by increasing temperature weakened runoff to some extent in spite of the fact that precipitation increased over the past 50 years.     

一株高产抗菌活性物质链霉菌的初步分类鉴定

对一株土壤中筛选出的可以产抗菌活性物质的链霉菌进行了研究，测定了该菌的抗菌谱，发现该菌株对多种植物病原性真菌及细菌有拮抗作用，但对植物病原性真菌的抑制效果低于植物病原性细菌.通过形态特征、培养特征、生理生化特性及抑菌谱等系列比较，发现该链霉菌菌株与链霉菌属的黑胡桃链霉菌(Streptomyces nogalater)的特征基本相符；通过16S?rDNA序列比对，发现该菌株16S?rDNA与黑胡桃链霉菌的16S?rDNA同源性达99％.根据多项分类原则和系统进化树的构建分析，将该菌株暂归入黑胡桃链霉菌类.