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31.
低温等离子体技术改善生物膜反应器载体表面性能的研究   总被引:4,自引:0,他引:4  
通常,微生物及广为应用的多聚体型生物载体表面均带有有负电荷。两者间产生的静电斥力严重阻碍了载体表面生物膜的形成。为强化微生物的载体上附着,提出了载体表面电荷改性新技术;低温等离子体氧化-Fe离子沉积技术。研究了4种等离子体对4种聚合载体(PE、PP、PS和PVC)的氧化强度及Fe^3+在处理后载体上的沉积。实验表明,处理后的载体表面生物膜形成速度加快,生物量显著增加,这项新技术为开发生物膜反应器新  相似文献   
32.
As GIS becomes an increasingly more ‘user-friendly’ tool, and more people recognize the benefits of the technology in their work environment, inevitably greater use will be made of it for a wide range of applications. The ease with which a GIS can now be used often overshadows the complexity underlying this technology and the potential difficulties that can (and do) arise when this is not fully understood. In practice, there are two routes open to the application of GIS technology for environmental studies. The first is to commission new data for the research. The second is to make use of existing data sets. Data are at the heart of any GIS application. A detailed knowledge about the data sources, the method of collection, capture, scale and sampling strategy, especially if the data are to be used in any analysis, modelling or simulation studies, is fundamental to any application. Unfortunately, information about data (metadata) is seldom available, especially for archival or legacy data sets. Furthermore, although it is now relatively easy to acquire digital data, to input, store, manipulate and display this data, and to output the results of any GIS analysis in the practical sense, little consideration is given to the problems associated with data quality and how this will ultimately affect present and future analyses and use of the output for planning and decision-making. The need to raise awareness about data quality for applications is set in the context of the development of an environmental database for the Moray Firth. Northeast Scotland, and more specifically the use of selected data sets from the database to aid in the proposed siting of an artificial reef. Using this example, this contribution explores the problems associated with the use of both existing analog and digital data sets as the basis for environmental applications, the problems of data acquisition, data quality, data standards, error and how these can affect the operational use of the data in GIS analyses. The solution to such problems appears to lie with improved error assessment and reporting. The outcome of this contribution is an attempt to offer guidance and solutions to researchers and applications specialists undertaking similar studies, by suggesting to what extent studies, such as the artificial reef siting, can safely make use of existing data sets without risking the problems associated with judgements based on inadequate information, and generated or inherent error.  相似文献   
33.
In order to assess the oxidation self-heating hazard of sulfurized rust, for particular ambient conditions in crude oil tanks, the support vector machine (SVM) technique is applied to predict the maximum temperature (Tmax) of oxidation self-heating process. Five governing parameters are selected, i.e. the water content, mass of sulfurized rust, operating temperature, air flow rate and oxygen concentration in the respiratory/safety valve. The efficiency and validity of the SVM predictions are investigated in the case of two sets of data: more than 85 experiments performed in academic lab (China) and almost 17 additional results collected from existing literature. Two main steps are also discussed: the training process (on selected subsets of data) and prediction process (for the remaining subsets of data). It can be concluded that for both datasets the maximum temperature (Tmax) values calculated by SVM technique were in good accordance with the experimental results, with relative errors smaller than 15% except for a few cases.The SVM technique seems therefore to be relevant and very helpful for complex implicit processes such as chemical reactions, as it is the case of the oxidation of sulfurized rust in oil tanks. Furthermore, such predictive methods can be continuously be improved through additional experiments feedback (larger databases) and can then be of crucial help for monitoring and early warning of hazardous reactions.  相似文献   
34.
郭荣芬  罗燕  唐盛 《灾害学》2015,(1):102-107
2004年5月10日云南怒江州福贡县石月亮乡发生泥石流等地质灾害,造成人员、经济重大损失。分析了此次泥石流形成的条件,并着重探讨了天气学成因,结果表明:脆弱的地质环境、陡峻的迎风坡、便于集水、集物的地形地貌和丰富的松散物质是怒江贡山泥石流易发生的有利地质地貌条件;连续性累积降水及短时间暴雨的产生为泥石流提供了较好的水源条件;高原短波槽与孟加拉湾南支槽东移合并,中、低层槽前西偏南暖湿气流500 h Pa偏西北气流是形成怒江暴雨过程的大尺度天气环流背景;地面辐合线、干线、低层显著湿区、湿舌等是导致降水的中尺度系统;高能高湿的潜在不稳定及近地层的水汽辐合是暴雨发生的有利条件;多普勒雷达图10~20 d Bz分散的絮状回波、部分35 d Bz块絮状回波、卫星云图多絮状对流云、无强对流云团活动反映此次暴雨过程为非对流性暴雨。  相似文献   
35.
环境风险预警方法与应急成套装备的应用展望   总被引:1,自引:0,他引:1  
介绍了环境风险预警方法建立的环境风险预警指标体系、环境风险源管理平台、环境风险源风险评估技术方法以及模块式应急成套装备的技术特点等;分析了环境风险预警方法与应急成套设备在危险化学品环境风险与应急管理,在区域大气环境挥发性有机污染物(VOCs)监控预警等方面的实际需求。面临现实的环境风险状况从环境风险防控与应急工程技术研究中心建设角度提出了需进一步完善、开发的环境风险预测预警技术与应急成套装备等新思路。  相似文献   
36.
Anaerobic processes are widely used for treatment of organic wastes. Fixed-film anaerobic processes are capable of handling high organic loads due to higher biomass concentration in the form of biofilms. Anaerobic biofilm reactor startup is greatly influenced by environmental, cellular and surface factors, and is often hindered by low growth rates of anaerobes and their strict environmental requirements. However, these obstacles can be overcome by applying appropriate startup strategies.  相似文献   
37.
The US Army Engineering Research Development Center (ERDC) uses a modified form of the Revised Universal Soil Loss Equation (RUSLE) to estimate spatially explicit rates of soil erosion by water across military training facilities. One modification involves the RUSLE support practice factor (P factor), which is used to account for the effect of disturbance by human activities on erosion rates. Since disturbance from off-road military vehicular traffic moving through complex landscapes varies spatially, a spatially explicit nonlinear regression model (disturbance model) is used to predict the distribution of P factor values across a training facility. This research analyzes the uncertainty in this model's disturbance predictions for the Fort Hood training facility in order to determine both the spatial distribution of prediction uncertainty and the contribution of different error sources to that uncertainty. This analysis shows that a three-category vegetation map used by the disturbance model was the greatest source of prediction uncertainty, especially for the map categories shrub and tree. In areas mapped as grass, modeling error (uncertainty associated with the model parameter estimates) was the largest uncertainty source. These results indicate that the use of a high-quality vegetation map that is periodically updated to reflect current vegetation distributions, would produce the greatest reductions in disturbance prediction uncertainty.  相似文献   
38.
人类工效型背具的研究   总被引:1,自引:0,他引:1  
从人类工效学和劳动生理学角度,对背具的肩带宽度、内背架设置等进行了实验研究和实用效果评价。对背具的设计原则和生物力学配置提出了建议和改进方法  相似文献   
39.
The clearing of forests to obtain land for pasture and agriculture and the replacement of autochthonous species by other faster-growing varieties of trees for timber have both led to the loss of vast areas of forest worldwide. At present, many developed countries are attempting to reverse these effects, establishing policies for the restoration of older woodland systems. Reforestation is a complex matter, planned and carried out by experts who need objective information regarding the type of forest that can be sustained in each area. This information is obtained by drawing up feasibility models constructed using statistical methods that make use of the information provided by morphological and environmental variables (height, gradient, rainfall, etc.) that partially condition the presence or absence of a specific kind of forestation in an area. The aim of this work is to construct a set of feasibility models for woodland located in the basin of the River Liébana (NW Spain), to serve as a support tool for the experts entrusted with carrying out the reforestation project. The techniques used are multilayer perceptron neural networks and support vector machines. Their results will be compared to the results obtained by traditional techniques (such as discriminant analysis and logistic regression) by measuring the degree of fit between each model and the existing distribution of woodlands. The interpretation and problems of the feasibility models are commented on in the Discussion section.  相似文献   
40.
一体化污水处理设备的应用与发展   总被引:7,自引:0,他引:7  
针对目前的污水处理形势 ,分析了一体化污水处理设备的优点和优势。并介绍了一体化污水处理设备一般工艺及其近年来技术发展概况  相似文献   
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