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181.
论地质灾害防治对策及其系统决策 总被引:4,自引:1,他引:3
本文在讨论地质灾害基本属性的基础上,提出了地质灾害防治的基本对策,并基于多目标决策特点,构造了三类地质灾害防治决策最优化模型。 相似文献
182.
Thermal runaway was studied in a continuous tubular pilot reactor under steady-state regime. Different accident scenarii were conducted by making some errors on reactant concentrations and/or temperature feed. To prevent thermal runaway, control by direct contact by solvent injection was used at different reactor locations. This injection allowed controlling the maximum reaction temperature. A simplified analytical method to estimate the maximum reaction temperature along the reactor was used.Benefit of this control method was the diminution of computational time. Furthermore, by injecting solvent to control maximum reaction temperature, there is no need to shut down the unit. The control method was validated experimentally. 相似文献
183.
Juan Carlos Moreno Saiz Felipe Domínguez Lozano Manuel Marrero Gómez Ángel Bañares Baudet 《Conservation biology》2015,29(3):910-919
The International Union for Conservation of Nature (IUCN) Red List Index (RLI) is used to measure trends in extinction risk of species over time. The development of 2 red lists for Spanish vascular flora during the past decade allowed us to apply the IUCN RLI to vascular plants in an area belonging to a global biodiversity hotspot. We used the Spanish Red Lists from 2000 and 2010 to assess changes in level of threat at a national scale and at the subnational scales of Canary Islands, Balearic Islands, and peninsular Spain. We assigned retrospective IUCN categories of threat to 98 species included in the Spanish Red List of 2010 but absent in the Spanish Red List of 2000. In addition, we tested the effect of different random and taxonomic and spatial Spanish samples on the overall RLI value. From 2000 to 2010, the IUCN categories of 768 species changed (10% of Spanish flora), mainly due to improved knowledge (63%), modifications in IUCN criteria (14%), and changes in threat status (12%). All measured national and subnational RLI values decreased during this period, indicating a general decline in the conservation status of the Spanish vascular flora. The Canarian RLI value (0.84) was the lowest, although the fastest deterioration in conservation status occurred on peninsular Spain (from 0.93 in 2000 to 0.92 in 2010). The RLI values based on subsamples of the Spanish Red List were not representative of RLI values for the entire country, which would discourage the use of small areas or small taxonomic samples to assess general trends in the endangerment of national biotas. The role of the RLI in monitoring of changes in biodiversity at the global and regional scales needs further reassessment because additional areas and taxa are necessary to determine whether the index is sufficiently sensitive for use in assessing temporal changes in species’ risk of extinction. 相似文献
184.
Diego Andrés Lugo 《Journal of Land Use Science》2020,15(2-3):343-367
ABSTRACT This article, through the use of political ecology perspectives on coercive conservation, aims to explain how in two separate Colombian Natural Parks and buffer zones, environmental policies designed to (re)take control of the frontier, have produced a similar territorial differentiation in the contention of illicit activities. Los Farallones in the Colombian Pacific and La Macarena/Puerto Rico in the Ariari region have experienced different stages of the armed conflict and are at the center of this analysis. I argue that in the contexts of both conflict escalation (1998–2007) and conflict de-escalation (2008–2016), the State in its attempt to control the frontier has not only had military intervention in areas of conservation but has also reinforced environmental programs that attack illegal mining and coca, producing both a territorially differentiated containment of illicit activities and an uneven progression of the illicit frontier. 相似文献
185.
本文概述土地退化的原因和状况。通过对广东山区土壤和东江流域低产耕地的大批土壤剖面分析数据的统计和推算,结果表明,广东的林地退化面积约占全省陆地面积的35%;旱地土地退化面积占全省旱地总面积的95%;水田土地退化面积约占全省水田总面积的25%。根据广东的省情,提出土地退化治理的对策:提高认识,增加投入,组织力量,开展调查摸底;制订整体治理规划,分步实施;明确治理的中心任务,推进面上治理利用,加强研究工作。 相似文献
186.
A Global Indicator for Biological Invasion 总被引:2,自引:0,他引:2
Abstract: "Trends in invasive alien species" is one of only two indicators of threat to biodiversity that form part of the Convention on Biological Diversity's (CBD) framework for monitoring progress toward its "2010 target" (i.e., the commitment to achieve by 2010 a significant reduction in the current rate of biodiversity loss). To date, however, there is no fully developed indicator for invasive alien species (IAS) that combines trends, derived from a standard set of methods, across species groups, ecosystems, and regions. Here we provide a rationale for the form and characteristics of an indicator of trends in IAS that will meet the 2010 framework goal and targets for this indicator. We suggest single and composite indicators that include problem-status and management-status measures that are designed to be flexible, readily disaggregated, and as far as possible draw on existing data. The single indicators at national and global scales are number of IAS and numbers of operational management plans for IAS. Global trends in IAS are measured as the progress of nations toward the targets of stabilizing IAS numbers and the implementation of IAS management plans. The proposed global indicator thus represents a minimum information set that most directly addresses the indicator objective and simultaneously aims to maximize national participation. This global indicator now requires testing to assess its accuracy, sensitivity, and tractability. Although it may not be possible to achieve the desired objective for a global indicator of biological invasion by 2010 as comprehensively as desired, it seems possible to obtain trend estimates for a component of the taxa, ecosystems, and regions involved. Importantly, current indicator development initiatives will also contribute to developing the mechanisms necessary for monitoring global trends in IAS beyond 2010. 相似文献
187.
188.
Ahmad R. Shouman 《Journal of Loss Prevention in the Process Industries》1998,11(6):383-390
A very simple solution to the thermal explosion problem for one-dimensional solids is presented. The solution produces analytical expressions for the criticality condition. Two different solutions are used. One solution gives higher answers than those known from exact solutions and the second solution gives lower answers. This allows bracketing the expected answer with a determined tolerance. The results obtained compare quite favorably with those obtained from known exact numerical solutions. This allows the utilization of the present method for many a practical problem with an acceptable tolerances. 相似文献
189.
基于LonWorks现场总线技术的城市污水处理系统的设计与实现 总被引:1,自引:0,他引:1
主要讨论了利用LonWorks现场总线技术来实现城市污水处理厂污水处理系统的实时控制,本系统采用IPC和PLC控制结构对现场的各种设备进行实时控制和数据的采集,通过LonWorks现场总线网络自动收集和传输污水处理系统的数据到中心控制室,中心控制室的计算机分析数据后对现场进行实时监控,实现污水处理的自动控制和无人化管理,中心控制室也可以通过Internet与远程终端互相通讯,向各终端提供实时的数据和远程终端对污水处理系统的实时监控。 相似文献
190.