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91.
提出了一种基于局部自动搜索和光谱匹配技术的监督分类训练样本的纯化方法。该方法首先利用遥感影像中像元的灰度信息在图像上局部范围内自动搜索和选择最佳样区位置,然后利用光谱匹配的思想对寻找到的最佳样区在光谱空间上进一步纯化。实验结果证明,通过手工选择样区的辅助,该算法能够自动有效地搜寻到最佳样区的位置,并对最佳样区进行纯化处理。原始遥感图像经过本文的样区纯化算法处理后,无论是目视判读效果,还是分类后混淆矩阵的统计及分类精度,均优于纯化处理前的分类结果,具有一定的实用价值。 相似文献
92.
ZHANGHu-Cheng YUMu-Qing TIANWei YUJian FUYou-Bao WANGXiao-Dong 《湿地科学》2004,2(4):309-313
Plenty of inorganic nitrogen in wastewater can cause the eutrophication in water bodies, so it is an important task to remove nitrogen. Purification role was realized by absorption, filtration, depositon, evaporation, nitrification and denitrification of microbes. Although the studies of Phragmites austrilis bed in the constructed wetland are popular, the purification performances of constructed wetland filled by saline-alkali soil substrate are less reported. In the paper, the purification efficiency of nitrogen with Phragmites austrilis bed in the constructed wetland filled by saline-alkali soil substrate was discussed through a simulation study. Results to date indicated that the first order plug flow model was adequate to describe the nitrogen removal. The experiment showed that the diminishing concentration of TN, NO2-N, NO3-N, NH4-N were closely related to hydrological retention time (HRT), the correlation coefficient was R^2 = 0.98499, R^2 = 0.9911, R^2 = 0.89407 and R^2 = 0.95459, respectively. According to the data, the most suitable hydrological retention time (HRT) for this kind of constructed wetland should be determined to 4 days. In addition, the experiment showed the purification efficiency of nitrogen has very broad range and drastic vibration, TN( 17 % - 79 % ), NO2-N (33%-98% ), NO3-N (13%-93% ), NH4-N (28%-64% ). The study will promote wetland‘s design and operation procedures in large saline-alkallne soil areas. 相似文献
93.
A history of water pollution and countermeasures for water purification in Dokai Bay, Japan are reviewed. Now, Dokai Bay suffers from the occurrences of red tides and oxygen-deficiency in summer. In order to prevent the occurrences of red tides and oxygen-deficiency, an ecological numerical model has been developed. The model experiments forecast that when the phosphorus or nitrogen load from land will be cut by 90% or 95%, respectively, red tides and oxygen-deficiency will not occur in Dokai Bay. If the industrial and sewage facilities are not sufficient to cut the nutrients load to the necessary degree, we have to consider other countermeasures such as cultivating bivalves and algae in order to decrease the nutrients concentration in the bay. International co-operation related to coastal zone management is also discussed. 相似文献
94.
In 1994, 28 sewage purification plants based on common reed Phragmites australis were analyzed, to study fragmentation effects on diversity and on food web structure of insect communities. Purification plants differed in age (2 to 11 years) and area (10 to 2,500 m2). Both age and area were significantly correlated with species richness of herbivores. Populations of the two most abundant herbivores, the gall makers Lipara pullitarsis (Diptera, Chloropidae) and Giraudiella inclusa (Diptera, Cecidomyiidae), increased significantly with age and size of the Phragmites habitats, i.e. the purification plants. Incidence curves showed that only habitats older than 6 years and larger than 100 m2 have a 50% probability of finding these two most abundant gall makers, and can correspondingly be considered to contribute to insect species conservation. Natural enemies were even more susceptible to habitat fragmentation than their phytophagous hosts or prey, thereby hampering possible biocontrol. Percent parasitism of both the Lipara and Giraudiella gall makers significantly increased with habitat age. 相似文献
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97.
锍镍试金-等离子体质谱法测定地球化学勘探样品中的铂族元素和金Ⅱ.分析流程空白的降低 总被引:26,自引:8,他引:26
对锍镍试金富集-等离子体质谱法测定贵金属流程中的试剂空白进行了检查,并对空白主要来源-捕集剂镍的各种纯化方法作了对比,提出了回收试金流程中溶扣后滤液中的镍循环使用。在有效降低空白的基础上,满足了化探样品所要求的0.0x ng/g级检出限,对超痕量贵金属标样分析结果与标准值符合。 相似文献
98.
非金属矿物的改型改性及其在环境保护中的应用 总被引:1,自引:0,他引:1
沸石、粘土矿物及石棉都是重要的非金属矿物。通过物理的和化学的改型改性,可以明显地提高沸石及粘土矿物的离子交换性、吸附性及催化性等,可用作环境中无机和有机毒物的离子交换剂、吸附剂或燃烧催化剂。对石棉的表面改性则可以抑制或改变石棉的有害生理活性,减少石棉生产以人体及环境的危害。 相似文献
99.
本文简略地叙述了萤石的物理特性及共生矿物组合。根据萤石的物理化学性质,选择了对萤石的分选方法,并着重分析了用重选和浮选法分离萤石的技术方案比较,确认用浮选法分离萤石是有效的方法之一,因而对用浮选法分离萤石进行了一系列的不同药剂种类和用量试验,并选择了对萤石富集比较有效的药剂对某铁矿中微细萤石的浮选富集和提纯,结果采用粗选与精选相结合的提纯流程,可以达到预想的目的,萤石的纯度可达97%左右。 相似文献
100.
以杂色鲍(Haliotis diversicolor Reeve)为研究对象,通过密度梯度离心方法纯化得到高纯度血蓝蛋白,以其作为抗原皮下注射免疫新西兰大白兔,从而获得高效价的兔源多克隆抗血清。进一步通过Protein A抗原亲和纯化的方法对该抗血清纯化,最终获得效价更高、检测特异性更好的血蓝蛋白多克隆抗体。应用该抗体进行Western检测发现,鲍血淋巴中存在着多样的血蓝蛋白衍生产物;进一步结合质谱技术对其中35 kDa条带进行鉴定发现,其来源于血蓝蛋白I型亚基的H结构域。 相似文献