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41.
通过对2009—2012年度临沂市9县3区统计年鉴和变更调查中11个相关指标数据的搜集,借助MATLAB7.0软件平台,利用BP人工神经网络算法,算出2009—2012年度各县区土地利用集约度,并利用BP人工神经网络的预测功能,预测了2013年和2014年度土地利用集约度值,结果表明临沂市平均土地利用集约度水平正逐步从粗放利用发展到中度集约,兰山区土地利用集约度水平一直为高度集约,集约度居全市之首,罗庄区一直为中度集约,稳中有进。预计到2014年底,大部分县区在中度集约或以上,仅有费县、蒙阴2县为粗放利用。。  相似文献   
42.
本文论述了基于3S技术的临沂市国土资源数字执法系统总体框架、关键模块的设计与实现,介绍了本系统的执法业务数据的输入、编辑、存储、管理、分析与输出等功能。展示了本系统的强大的数据兼容、共享、数据处理及分析能力,为国土执法工作提供了科学决策和便捷高效的管理模式。  相似文献   
43.
A numerical method of statistical pattern recognition is proposed in this paper. Different from the discriminatory analysis method currently used in the mathemalic statistics, it is unnecessary to assume that the predictand should be subject to a certain distribution. On the contrary, the statistical relationship between predictand and predictor has been obtained directly with computer according to actual distribution to recognize the category of patterns. Result of forecast has been improved as compared with the usual analytic discriminatory method. The influence of predictor on predictand can be seen clearly from this method and the transparency is good. Therefore, it is better to use the method in very short range forecast for which causality is more obvious.  相似文献   
44.
Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) were measured in surface sediments in the Pearl River Delta, southern China. The concentrations ranged from 0.06 to 304 ng/g dry weight for TBBPA and from 0.03 to 31.6 ng/g for total HBCD. The correlations between the TBBPA and HBCD concentrations were significant in rivers (Dongjiang, Zhujiang, Beijiang, and Dayanhe Rivers) with local input sources but not significant in the Xijiang River and Pearl River Estuary without local sources. HBCD was dominated by γ-HBCD (averaged 52.5-75.0%), whereas α-HBCD contributions were relatively high in sediments from the urban areas. The enantiomeric fractions of γ-HBCD in the sediments (averaged from 0.431 ± 0.035 to 0.479 ± 0.010) differed significantly from that in HBCD technical product except for samples from the e-waste area (Dayanhe River, 0.488 ± 0.091). This suggests that enantioselective biotransformation of HBCD occurs in the aquatic environment in this region.  相似文献   
45.
以临沂市兰山区李官镇为例探讨了土地利用类型结构的分维特征,讨论了分维值与土地利用复杂性和稳定性的关系。经研究,李官镇土地利用结构具有分形特征,人为因素对农村道路、沟渠和有林地的影响突出,使得这3种土地利用类型结构呈现复杂化和不规则化,在以后的规划中应以合理规划农村道路,合理布局沟渠和有林地为主要思路,为土地利用科学规划提供辅助决策。  相似文献   
46.
The salinization of rivers, as indicated by salinity increases in the downstream direction, is characteristic of arid and semiarid regions throughout the world. Historically, salinity increases have been attributed to various mechanisms, including (1) evaporation and concentration during reservoir storage, irrigation, and subsequent reuse; (2) displacement of shallow saline ground water during irrigation; (3) erosion and dissolution of natural deposits; and/or (4) inflow of deep saline and/or geothermal ground water (ground water with elevated water temperature). In this study, investigation of salinity issues focused on identification of relative salinity contributions from anthropogenic and natural sources in the Lower Rio Grande in the New Mexico-Texas border region. Based on the conceptual model of the system, the various sources of water and, therefore, salinity to the Lower Rio Grande were identified, and a sampling plan was designed to characterize these sources. Analysis results for boron (delta(11)B), sulfur (delta(34)S), oxygen (delta(18)O), hydrogen (delta(2)H), and strontium ((87)Sr/(86)Sr) isotopes, as well as basic chemical data, confirmed the hypothesis that the dominant salinity contributions are from deep ground water inflow to the Rio Grande. The stable isotopic ratios identified the deep ground water inflow as distinctive, with characteristic isotopic signatures. These analyses indicate that it is not possible to reproduce the observed salinization by evapotranspiration and agricultural processes alone. This investigation further confirms that proper application of multiple isotopic and geochemical tracers can be used to identify and constrain multiple sources of solutes in complex river systems.  相似文献   
47.
Sixteen sediment samples collected from eight transects in a mangrove swamp of the Jiulong River Estuary, Fujian, China were investigated for their content of polycyclic aromatic hydrocarbons (PAHs) and the biodegradation potential of the indigenous microorganisms. The bacterial community structures in the mangrove sediments and in enrichment cultures were also investigated. The results showed that the total PAHs concentration of mangrove sediments ranged from 280 to 1074 ng g(-1) dry weight, that the PAHs composition pattern in the mangrove sediments was dominated by high molecular weight PAH components (4-6 rings), and that Benzo[ghi]perylene and Indeno[1,2,3-cd]pyrene were the most dominant at different stations. Abundant PAH-degrading bacteria were found in all the stations, the values of phenanthrene-degrading bacteria ranged from 5.85 x 10(4) to 7.80 x 10(5) CFU g(-1) dry weight, fluoranthene-degrading bacteria ranged from 5.25 x 10(4) to 5.79 x 10(5) CFU g(-1) dry weight, pyrene-degrading bacteria ranged from 3.10 x 10(4) to 6.97 x 10(5) CFU g(-1) dry weight and the benzo(a)pyrene-degrading bacteria ranged from 5.25 x 10(4) to 7.26 x 10(5) CFU g(-1) dry weight. DGGE analysis of PCR-amplified 16S rDNA gene fragments confirmed that there was a remarkable shift in the composition of the bacterial community due to the addition of the different model PAH compound phenanthrene (three ring PAH), fluoranthene(four ring PAH), pyrene(four ring PAH) and benzo(a)pyrene(five ring PAH) during enrichment batch culture. Eleven strains were obtained with different morphology and different degradation ability. The presence of common bands for microbial species in the cultures and in the native mangrove sediment DNA indicated that these strains could be potential in situ PAH-degraders.  相似文献   
48.
Heavy oil contamination is one of the most important environmental issues. Toxicities of polycyclic aromatic hydrocarbons (PAHs), including immune toxicities, are well characterized, however, the immune toxic effects of heavy oil, as a complex mixture of PAHs, have not been investigated. In the present study, we selected Japanese flounder (Paralichthys olivaceus) as a model organism, and observed alteration of immune function by the exposure to heavy oil. To analyze the expression profiles of immune system-related genes, we selected 309 cDNAs from our flounder EST library, and spotted them on a glass slide. Using this cDNA array, alteration of gene expression profiles was analyzed in the kidneys of flounders exposed to heavy oil. Six Japanese flounders (mean body weight: 197 g) were acclimated to laboratory conditions at 19-20 degrees C. Three fish were exposed to heavy oil C (bunker C) at a concentration of 3.8 g/L for 3 days, and the others were kept in seawater without heavy oil and used as the control. After the exposure period, the fish were transferred into control seawater and maintained for 4 days, and then they were dissected and their kidneys were removed. Total RNA was extracted from the kidney samples to use in gene expression analyses. The microarray detected alteration of immune system-related genes in the kidneys of heavy oil-exposed flounders, including down-regulation of immunoglobulin light chain, CD45, major histocompatibility complex class II antigens and macrophage colony-stimulating factor precursor, and up-regulation of interleukin-8 and lysozyme. These results suggest that pathogen resistance may be weakened in heavy oil-exposed fish, causing a subsequent bacterial infection, and then proinflammatory genes may be induced as a defensive response against the infection. Additionally, we found candidate genes for use as biomarkers of heavy oil exposure, such as N-myc downstream regulated gene 1 and heat shock cognate 71 kDa proteins.  相似文献   
49.
东亚温带低气压路径   总被引:4,自引:0,他引:4  
王荣华 《气象学报》1963,33(1):15-24
本文利用1951—1960年的亚洲地面天气图,分月統計东亚地区(70°E以东,55°N以南)每2.5°×2.5°經緯格內低压中心通过的頻数,繪制了頻数分布图,确定出低压移动的主要路径,此外,还繪制了冬半年和夏半年低压发生(初現)頻数分布图、頻数百分率的随緯度分布和沿120°E与110°E經线上低压中心通过頻数的各月綜合图。結果得出:1.东亚大陆中緯度西风带的低压主要出現在蒙古人民共和国中部到我国的东北地区,20°N以南不出現溫带低气压;2.45°N以南的我国大陆上低压很弱,大多数不閉合,只有在我国东部或入海后才发展;3.日本东南面海上是低压路径的集中带;4.春季低压出現最为頻繁,秋季次之,夏季我国江淮流域低压有所增多。 最后,对低压路径进行了分类,把东亚的溫带低气压划为五大类和十一亚类,并对各类低压分别作了簡要的叙述。  相似文献   
50.
盐构造与油气成藏关系密切,一直是构造地质和石油地质研究的热点。滨里海盆地下二叠统孔谷阶发育巨厚盐层,并发育盐底辟、盐枕、盐滚、盐边凹陷、盐焊接和龟背等多种盐构造,盐构造类型多、变形机理各异。由于盐构造成因复杂,导致对盐构造宏观变形动力机制、下伏地层微地貌对上覆盐层构造变形影响等认识不清,制约了对盐构造形成机理的认识。本文根据滨里海盆地东缘地震资料和地层特征,建立了地质模型,设计了相应的盐构造物理模拟实验;通过物理模拟实验研究了盐构造变形动态过程,梳理了盐构造变形机理及与下伏地层之间的关系。结果表明:(1)早期盐层变形动力主要为外部挤压力和盐层滑脱流动变形,滨里海盆地构造变形外力主要来自东部乌拉尔造山作用,造山运动造成盐层塑性流动滑脱变形形成层间褶皱及与盐层相关的断裂;(2)晚期盐构造幅度和巨厚盐丘形成动力主要为上覆沉积物的差异负载和下伏地层微地貌古构造背景,在滨里海盆地晚二叠世到三叠纪,来自东部乌拉尔褶皱带的碎屑物持续向盆地充填沉积形成差异负载,造成盐层纵向的剧烈变形,而下伏地层正向微地貌加速了这种变形。这些试验结果对滨里海盆地盐相关构造的认识和油气勘探有重要的指导作用。  相似文献   
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