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991.
TiO2/Ni PECO体系降解DMP的动力学和光电协同作用研究 总被引:2,自引:1,他引:1
以采用微波辅助法制备的TiO2/Ni光电极为阳极,纤维状石墨毡材料(graphite felt,GF)为阴极,饱和甘汞电极(saturated calomel electrode, SCE)为参比电极建立TiO2/Ni 光电催化氧化(PECO)体系。以邻苯二甲酸二甲酯(dimethy phthalate,DMP)为目标物,研究其光电催化降解反应动力学和光电协同作用。结果显示:DMP的降解符合拟一级动力学规律;当DMP初始浓度一定时,影响DMP光电催化降解速率的因素由强到弱依次为:催化剂有效面积,紫外光强度,曝氧速率,外加偏转电压等。实验证明本体系中光电之间具有协同作用。 相似文献
992.
危险品运输网络中运输方式和路径优化研究 总被引:2,自引:1,他引:1
在危险品运输网络中,往往有多种运输方式和多条运输路径。不同运输方式在不同路径上发生事故所造成的损失不同,不同运输方式的单位运输成本也不同。本文研究了在给定运输起点和终点的情况下,在综合考虑事故所造成的损失最小和运输成本最小的情况下,运输方式和运输路径的选择方法。通过一个仿真例子说明了模型的求解方法和实际效果,并与单一运输方式的方案进行了对比。结果表明考虑运输方式的组合,在一定程度上可以降低危险品运输过程中的社会总期望损失和运输成本。 相似文献
993.
994.
Current United States National Park Service (NPS) management is challenged to balance visitor use with the environmental and
social consequences of automobile use. Wildlife populations in national parks are increasingly vulnerable to road impacts.
Other than isolated reports on the incidence of road-related mortality, there is little knowledge of how roads might affect
wildlife populations throughout the national park system. Researchers at the Western Transportation Institute synthesized
information obtained from a system-wide survey of resource managers to assess the magnitude of their concerns on the impacts
of roads on park wildlife. The results characterize current conditions and help identify wildlife-transportation conflicts.
A total of 196 national park management units (NPS units) were contacted and 106 responded to our questionnaire. Park resource
managers responded that over half of the NPS units’ existing transportation systems were at or above capacity, with traffic
volumes currently high or very high in one quarter of them and traffic expected to increase in the majority of units. Data
is not generally collected systematically on road-related mortality to wildlife, yet nearly half of the respondents believed
road-caused mortality significantly affected wildlife populations. Over one-half believed habitat fragmentation was affecting
wildlife populations. Despite these expressed concerns, only 36% of the NPS units used some form of mitigation method to reduce
road impacts on wildlife. Nearly half of the respondents expect that these impacts would only worsen in the next five years.
Our results underscore the importance for a more systematic approach to address wildlife-roadway conflicts for a situation
that is expected to increase in the next five to ten years. 相似文献
995.
Abstract: The brown tree snake ( Boiga irregularis ) is a devastating invader that has ecologically and economically affected Guam and is poised to disperse further. Interdiction efforts are being conducted on Guam and some of the potential receiving sites, but no tools exist for evaluating the potential for snake incursion; thus, the amount of effort that should be invested in protecting particular sites is unknown. We devised a model that predicts the relative risk of establishment of the brown tree snake (BTS) at a given site. To calculate overall risk, we incorporated in the model information on the likelihood of an organism entering the transportation system, avoiding detection, surviving to arrive at another location, and establishing at the receiving end. On the basis of documented rates of snake arrival at receiving sites, the model produced realistic predictions of invasion risk. Model outputs can thus be used to prioritize interdiction efforts to focus on especially vulnerable receiving locations. We provide examples of the utility of the model in evaluating the impacts of changes in transportation parameters. Finally, the model can be used to evaluate the impacts that BTS establishment at an additional site and that creation of a new source of snakes would have. The use of qualitative inputs allows the model to be adapted by substituting data on other invasive species or transportation systems. 相似文献
996.
Jiangwei WangSuqin Li Guohong Xiong Daqiang Cang 《Resources, Conservation and Recycling》2011,55(8):755-759
To improve the efficiency of water use and reuse, a digitalized water network system was implemented in a steel industrial complex. The system consisted of four parts: online instrument and sensing devices, programmable logic controller, data communication network and control center based on expert knowledge. The system achieved real-time monitoring, diagnosis, and early warning of cooling water system using data collected inline, and enabled data connectivity and transmission of self-developed software applications on personal computer. This research used a steel enterprise as a case study. After the analysis of its cooling water system and water-saving potential using water balance test, a digitalized water network was evaluated and implemented, and we believe this network can be suitable for steel industry in general. 相似文献
997.
徐海根 《生态与农村环境学报》1998,(4)
在我国生物多样性信息系统现状调查研究的基础上,进行了包括逻辑结构、组织结构和网络结构的系统建设的结构设计,提出了今后工作的重点,讨论了与信息系统建设有关的资金、运作机制和数据源点建设等问题。 相似文献
998.
999.
Scholars have long stressed the need to bridge the gap between science and action and seek the most efficient use of knowledge for decision making. Many contributors have attempted to consider and understand the sociopolitical forces involved in knowledge generation and exchange. We argue, however, that a model is still needed to adequately conceptualize and frame the knowledge networks in which these processes are embedded. We devised a model for knowledge mapping as a prerequisite for knowledge management in the context of conservation. Using great ape conservation to frame our approach, we propose that knowledge mapping should be based on 2 key principles. First, each conservation network results from the conglomeration of subnetworks of expertise producing and using knowledge. Second, beyond the research-management gradient, other dimensions, such as the scale of operation, geographic location, and organizational characteristics, must also be considered. Assessing both knowledge production and trajectory across different dimensions of the network opens new space for investigating and reducing the gap between science and action. 相似文献
1000.
大力发展现代物流业和皖江城市带承接产业转移示范区建设是两大重要国家级战略.首先对轴—辐理论的国内外研究现状进行了总结和归纳,分析了轴—辐网络的结构及其优劣势.其次,设计了物流中心性指数的评价指标体系,运用主成分分析法对皖江城市带的9个地级城市进行物流节点等级划分,根据分析结果的总得分和区位特征确定合肥、芜湖、安庆3个一级物流节点,形成轴三角.分析了各级物流节点间的干线及支线物流通道,构建了皖江城市带轴—辐物流网络空间. 相似文献