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61.
G3技术集成及其在青藏铁路信息化中的应用研究 总被引:2,自引:0,他引:2
青藏铁路是世界上海拔最高、线路最长的高原铁路。铁路沿线环境恶劣(严寒缺氧,气候恶劣、多年冻土地段长、生态环境脆弱等)。因此,不仅要求在工程建设过程中采用先进的设备和技术手段,而且,要求在线路建成后实现其运营、维修管理信息化。笔者提出采用G3(包括全球定位系统GPS、地理信息系统GIS、全球移动通讯系统GSM)技术集成来确保建成后线路的安全运营。在集成系统中:GPS主要用于实施、快速地获取空间目标的三维坐标;GIS为系统集成提供基础平台,对空间信息进行综合分析和综合处理;GSM实现信息的无线、实时的传输。采用G3技术可以实现列车行车信息的实时发布、传输与接收,实现数据共享,从而保证行车安全。 相似文献
62.
生物修复中的酶学技术研究与展望 总被引:2,自引:0,他引:2
随着对活性污泥工艺和废水除污技术的不断了解,开发不同的策略来研究这些污染物的降解已成为必要,其中酶技术越来越受到人们的关注。作者简单介绍了生物补救技术的研究现状及存在的一些问题,详细介绍了酶在生物除污、生物打浆、生物漂白、生物浸矿过程中的最新发展,并对该领域作了展望。 相似文献
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M Calabi-Floody G Velásquez L Gianfreda S Saggar N Bolan C Rumpel ML Mora 《Chemosphere》2012,89(6):648-655
The high P retention of acidic Andisols makes necessary to increase our technological approaches in pasture management in the animal system production. Here, we evaluated the clay- or nanoclay-acid phosphatase complexes for improving phosphorus mineralization from degraded cattle dung. We implemented an immobilization mechanism of acid phosphatase (AP) using natural clays (allophanic and montmorillonite) and nanoclays as support materials. Also, we evaluated the mineralization of organic P containing in decomposed cattle dung with clay- and nanoclay-AP complexes by incubation studies. Clays and nanoclays were characterized by microscopy techniques as atomic force and confocal-laser scanning microscopy. We found that these support materials stabilized AP by encapsulation. Our results showed that immobilization on allophanic or montmorillonite materials improved both the specific activity (4-48%) and the Vmax (28-38%) of AP. Moreover, the enzyme had a better performance when immobilized on clay and nanoclay from Andisol than on montmorillonite materials. Phosphorous mineralization of cattle dung was regulated by water-soluble P present in the dung and P re-adsorption on allophanic materials. However, we were able to detect a potential capacity of AP immobilized on allophanic nanoclays as the best alternative for P mineralization. Further research with initially low water-soluble P containing organic materials is required to quantify the P mineralization potential and bioavailability of P from dung. 相似文献
65.
The widespread concern about pollution caused by Polycyclic Aromatic Hydrocarbons (PAHs) raises the question of how they affect soil microbial communities which are potentially involved in the transformation of these pollutants. Using microcosms, we describe the effect of anthracene, a model PAH, on microbial communities inhabiting a Pinus halepensis litter from both coastal (COS) and inland (INL) Mediterranean sites. The microcosms were incubated over 3 months (25 °C, 60% WHC) and the effects of anthracene on microbial activities of both litters were monitored. Different enzyme activities (laccase, cellulase, β-glucosidase and acid phosphatase) and microbial respiration were measured and variations in litter chemical composition over incubation were determined using 13C Nuclear Magnetic Resonance (NMR) from both sites. Our results show that lignocellulolytic enzymes increased markedly after a 3-month incubation in COS microcosms, especially in the presence of anthracene, whereas INL microcosms were not similarly affected. These results show that anthracene not only has no toxic effect on the microbial activities tested but actually enhances the lignocellulolytic activities of the fungal communities from coastal litters, demonstrating the detoxification potential and resistance of stressed Mediterranean coastal ecosystems. 相似文献
66.
比较金洞林场手工制图与计算机制图的特点;介绍现阶段金洞林场GIS技术开发林业图形系统的应用;介绍基于GIS技术开发的2012年金洞林场集体林权权属数据库系统的过程;分析在金洞林场GIS技术系统开发上的问题,并提出建议.参5. 相似文献
67.
Gang Guo Yayi Wang Tianwei Hao Di Wu Guang-Hao Chen 《Frontiers of Environmental Science & Engineering》2018,12(1):10
Nitrous oxide (N2O), a potent greenhouse gas, is emitted during nitrogen removal in wastewater treatment, significantly contributing to greenhouse effect. Nitrogen removal generally involves nitrification and denitrification catalyzed by specific enzymes. N2O production and consumption vary considerably in response to specific enzyme-catalyzed nitrogen imbalances, but the mechanisms are not yet completely understood. Studying the regulation of related enzymes’ activity is essential to minimize N2O emissions during wastewater treatment. This paper aims to review the poorly understood related enzymes that most commonly involved in producing and consuming N2O in terms of their nature, structure and catalytic mechanisms. The pathways of N2O emission during wastewater treatment are briefly introduced. The key environmental factors influencing N2O emission through regulatory enzymes are summarized and the enzyme-based mechanisms are revealed. Several enzymebased techniques for mitigating N2O emissions directly or indirectly are proposed. Finally, areas for further research on N2O release during wastewater treatment are discussed. 相似文献
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利用模糊集理论建立一种模糊综合评价方法来评价交通运输系统内部的公路客运站安全管理工作。分别通过评价语言变量和权重语言变量将评价指标体系的定性指标和定量指标及权重全部转化成三角形模糊数,克服定性与定量指标不具有可比性的缺点,使评价更客观、精确。基于最优度概念,将权重模糊评价矩阵转化成模糊单一评价矩阵,避免传统模糊数之间比较的复杂性和不精确性。考虑到评价者在模糊评价环境下对风险的态度,将乐观系数引入评价的过程。采用TOPSIS方法计算出评价方案的综合评价分数并进行排序。结合桂林市10个客运站安全管理工作评价实例,通过改变权重值对评价结果进行敏感性分析。方法概念清晰,计算过程直观与简单,评价结果公正与合理,不但可在交通系统内推广,同样也可适合于其他各领域模糊环境下的评价问题。 相似文献
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