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121.
基于智能交通运输系统(ITS)的交通安全控制体系研究 总被引:2,自引:5,他引:2
道路交通事故是当今世界最严重的公害之一 ,道路交通安全问题也受到世界各国的广泛重视。近十年 ,全球发展较快的智能交通运输系统 (ITS)使传统的交通运输状况大为改善 ,大大地提高了现有道路网的通行能力和交通运输的安全性 ,削弱或消除了以往诱发交通事故的不安全因素 ,有效地减少了交通事故的发生。笔者在简述了ITS的应用概况、基本功能以及智能汽车理论研发内容的基础上 ,论述了以ITS技术为基础的交通安全控制体系框架及其功效 ,阐明了我国快速发展ITS技术对提高道路交通安全水平具有重要的战略意义。 相似文献
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新时期城市构造呈现多样性,加上城市化、工业化发展迅猛,城市的演变日新月异,如何对城市土壤环境监测点位布设的方法进行取舍是十分关键的,本文详细介绍了城市土壤环境监测点位布设的方法以及其应用的研究分析,希望能为我国城市土壤环境监测的相关研究提供参考。 相似文献
124.
Juan Xie Xinyu Zhang Zhiwei Xu Guofu Yuan Xinzhai Tang Xiaomin Sun D. J. Ballantine 《Frontiers of Environmental Science & Engineering》2014,8(4):561-569
The concentrations of total phosphorus (TP) from 83 surface water sampling sites in 29 of the Chinese Ecosystem Research Network (CERN) monitored ecosystems, representing typical agro- and forest ecosystems, were assessed using monitoring data collected between 2004 and 2010 from still and flowing surface water. Results showed that, TP concentrations were significantly higher in agro-ecosystems than those in forest ecosystems both for still and flowing surface water. For agro- ecosystems, TP concentrations in the southern area were significantly higher than those in the northern and north- western areas for both still and flowing surface water, however no distinct spatial pattern was observed for forest ecosystems. In general, the median values of TP within agro- and forest ecosystems did not exceed the Class V guideline for still (0.2mg.L-1) or flowing (0.4mg.L-1) surface water, however, surface water at some agro- ecosystem sampling sites was frequently polluted by TE Elevated concentrations were mainly found in still surface water at the Changshu, Fukang, Linze and Naiman monitored ecosystems, where exceedance (〉 0.2 mg.L-1) frequencies varied from 43% to 78%. For flowing water, elevated TP concentrations were found at the Hailun, Changshu and Shapotou monitored ecosystems, where exceedance (〉 0.4 mg. L-1) frequencies varied from 29% to 100%. Irrational fertilization, frequent irrigation and livestock manure input might be the main contributors of high TP concentrations in these areas, and reduced fertilizer applications, improvements in irrigation practices and centralized treatment of animal waste are necessary to control P loss in these TP vulnerable zones. 相似文献
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水质自动监测系统的研究与探讨 总被引:1,自引:0,他引:1
对水质自动监测系统五参数、氨氮、总有机碳进行了比对测定,结果显示,该系统灵敏、准确、快捷、省力,与常规监测数据吻合较好.提出解决TOC与CODCr转换系数有关问题的建议. 相似文献
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大气化学机理是空气质量模型中重要的组成部分,是研究大气化学过程的重要手段和方法。综述了碳键机理(CBM)、区域大气化学机理(RACM)和加州大气污染研究中心机理(SAPRC)3类常用归纳化学机理的发展历程,比较了各化学机理在物种集总方式、物种数和化学反应数等方面的差异,介绍了各类大气化学机理最新版本的更新及在空气质量模型中的应用情况。对不同大气化学机理在空气质量模型中应用的比较进行了分析和总结,讨论了导致不同大气化学机理模拟结果差异的原因,并对空气质量模型中不同大气化学机理的选择和应用提出了建议。 相似文献
130.
Ingrid Öborn Jan Bengtsson Fredrik Hedenus Lotta Rydhmer Maria Stenström Katarina Vrede Charles Westin Ulf Magnusson 《Ambio》2013,42(7):823-839
To increase the awareness of society to the challenges of global food security, we developed five contrasting global and European scenarios for 2050 and used these to identify important issues for future agricultural research. Using a scenario development method known as morphological analysis, scenarios were constructed that took economic, political, technical, and environmental factors into account. With the scenarios as a starting point future challenges were discussed and research issues and questions were identified in an interactive process with stakeholders and researchers. Based on the outcome of this process, six socioeconomic and biophysical overarching challenges for future agricultural were formulated and related research issues identified. The outcome was compared with research priorities generated in five other research programs. In comparison, our research questions focus more on societal values and the role of consumers in influencing agricultural production, as well as on policy formulation and resolving conflicting goals, areas that are presently under-represented in agricultural research. The partly new and more interdisciplinary research priorities identified in Future Agriculture compared to other programs analyzed are likely a result of the methodological approach used, combining scenarios and interaction between stakeholders and researchers. 相似文献