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121.
介绍了高压开关柜局部放电特高频法测试的原理及特点,列举了电晕放电、悬浮放电、绝缘沿面放电共3种缺陷放电类型的特高频法的局部放电的幅值 -相位图及幅值 -放电次数统计图,并分析了上述3种放电类型的图谱特征。通过一起特高频法检测高压开关柜局部放电的案例,验证特高频法检测高压开关柜局部放电的实用性。 相似文献
122.
Summary. Under field conditions significantly more black
chafer, Holotrichia loochooana loochooana (Sawada)
(Coleoptera: Scarabaeidae) males landed on black and gray
sources than white ones containing 10 mg of female
pheromone, anthranilic acid. When a broader spectrum of
colours was tested the frequency of male landing was intensively
proportional to as the lightness of the colour of the
lures. These findings demonstrated that mate location by
H. l. loochooana males is dependent on
both olfactory and visual stimuli of the source. In contrast, female aggregation was not
affected by colour. 相似文献
123.
城市工业生态化发展战略定位研究--以广东江门市为例 总被引:1,自引:0,他引:1
文章利用产业区位熵、比较劳动生产率以及波及效果系数等指标,综合产业资源利用效率人分析、环境污染负荷分析等指标,对江门市的产业发展现状和资源环境负荷进行了实证分析,通过比较分析,对江门市工业生态化发展总体战略进行了合理定位、分阶段提出了江门市生态工业发展的目标和优先实施的产业发展重点。文中提出的指标与分析方法对于中国当前城市工业生态化转型战略的制定具有重要借鉴意义。 相似文献
124.
油气产业集群识别为完善区域油气产业发展规划和明确不同区域油气产业集群发育程度差异提供科学依据。本文油气产业集群识别包括产业集群地理边界确定和产业集群辨认,选择行政区划省(直辖市或自治区)作为油气产业集群识别的地理边界;基于企业数量区位熵、产业产值区位熵和就业区位熵提出复合区位熵概念CLQ,并据此将我国12个油气资源富集省区依油气产业集群发育程度辨认(识别)为三个梯队:第一梯队包括新疆、黑龙江、辽宁、天津、山东、甘肃6省区,油气产业上、下游均不同程度地发育产业集群;第二梯队包括陕西、吉林、河北、四川、青海5省区,油气产业上、下游并非均发育产业集群;第三梯队为河南,油气产业上、下游均不发育产业集群;进一步计算12省区油气产业上、下游的CLQ差值,结果表明,总体上我国这12个油气资源富集省区油气产业下游相对于上游发育不足,油气产业链出现"上游大,下游小"的畸形格局。 相似文献
125.
城市防灾减灾设施的层级选址问题建模 总被引:7,自引:0,他引:7
提出了城市防灾减灾设施的层级选址问题,并对其进行了分类.针对高低级设施相对独立和相互从属的层级选址问题进行了建模.依据城市防灾减灾设施选址问题的特点,提出了两阶段的层级选址过程:(1)使用位置集合覆盖模型确定能覆盖全部需求点所必需的最少设施数量和位置,作为基本等级设施的选址;(2)对独立型层级选址问题,使用最大覆盖准则确定高级设施的位置,对从属型层级选址问题,使用极小和准则确定高级设施的位置.对层级选址问题模型的应用进行了讨论. 相似文献
126.
The scientific literature regarding HEMS (Helicopter Emergency Medical Service) planning lacks a method for defining optimal sites for helipads that takes into account risk distribution and hospital location. Such a method could minimise overall rescue time in emergency situations. In this paper a method that supports the decisions taken by disaster planners and managers is developed, focusing on the quantification of necessary air resources for the management of some probable calamities. Given a region characterised by a natural and non-natural disaster risk map, along with a comprehensive transport system (also characterised by a risk map), a set of emergency destinations (hospitals), a set of heliports/helipads dislocated on the territory and a number of available HEMS rotorcraft, the aim of the paper is to assess the adequacy of the VTOL/FATO (Vertical Take-Off and Landing/Final Take-Off and Landing Area) system in order to deal with a set of possible emergencies. 相似文献
127.
建立了灾后企业选址的一种决策模型。对遭受自然或人为灾害打击中,不得不进行迁移的企业,如何实施有效的选址决策进行了研究,在给定假设的基础上,构造了一个非线性规划问题,提出了进行区位决策的迭代算法,并对如何解决已有多个企业及顾客有偏好的复杂情况进行了讨论,研究表明,在以市场竞争为导向的动态选址过程中,企业从最大程度地占有市场的目标出发,倾向于定位在一个特定的市场吸引点上。 相似文献
128.
Ezgi Orhan 《Environmental Hazards》2017,16(4):363-382
Despite global policies advocating risk reduction and community level recovery, post-disaster implementations usually focus on households, but fail to focus on businesses in spatial terms. Due to the lack of appropriate policy and tools, businesses often make their own location choices as part of their recovery strategy. In view of this, this study aims to establish the factors affecting the location choices of businesses challenged by disasters in the absence of any specific spatial strategies designed for them. In order to determine these factors, empirical research was conducted in Adapazari, Turkey on 232 firms selected as a result of a stratified random sampling procedure. According to the analysis of the results, the most notable impacts on business location choices after a disaster shock are associated with occupancy status, education level, and extent of damage. In line with these findings, the impacts of business location choices are discussed to highlight the role of businesses in spatial decisions. 相似文献
129.
Pinto DM Himanen SJ Nissinen A Nerg AM Holopainen JK 《Environmental pollution (Barking, Essex : 1987)》2008,156(1):227-231
In field O3-enrichment experiments increased herbivore densities have been reported, which could be due to negatively affected host location behavior of natural enemies. We addressed the impact of doubling background O3 on the host location of the parasitoid Cotesia plutellae by conducting 24-h trials in an open-air O3-fumigation system during two consecutive years. Two circles (radii 1.40 and 4.00 m) of Plutella xylostella-infested potted cabbage plants were placed in the O3 and ambient plots. Female wasps were released into each plot from the center, and observed 5 times over a 24-h period to assess their host location capability. Thereafter, plants were kept in laboratory conditions until larvae pupation to determine parasitism rates. No significant differences were detected between ambient and O3-enriched environments either in the number of wasps found in the field, or in the percentages of parasitized larvae. This suggests that moderately elevated O3 will not affect the behavior of this parasitoid. 相似文献
130.