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361.
本研究根据城市照明配电系统的运维经验,描述了城市照明配电系统单项接地事故的基本特征,分析了城市照明配电系统接地事故的根本原因,提供了处理城市照明配电系统单项接地故障,降低故障损害的方法,提出了降低城市照明配电系统单项接地故障的措施,希望对控制单相接地故障,提高城市照明配电系统稳定水平有所帮助。 相似文献
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导致土地信访的四大法制缺陷 总被引:1,自引:0,他引:1
欧爱民 《国土资源导刊(湖南)》2010,7(6):28-29
之所以会产生土地信访事件,普通民众话语权的缺乏是深层次原因,地权歧视是根本原因,不完善的征地制度是直接原因、权利救济制度的空转是现实成因。 相似文献
365.
中国处于经济快速发展阶段,建设用地需求日益激增的大背景下,建设用地普遍存在重批轻管的现象,批后管理环节比较薄弱。对于建设用地批后监管"难"的问题,本文通过深入分析建设用地批后监管的现状,以及监管"难"的原因,就如何加强对建设用地批后监管对策与措施。 相似文献
366.
正今年上半年,我们先后对12个省16个开发区的土地利用现状进行了全面深入的了解,并有针对性地推出了盘活低效用地的措施。第一,闲置低效用地的产业结构差异很大,存在于商品用地等各类用地中,主要集中在房地产用地。第二,闲置低效用地的成因复杂,主要是四大方面,一是政府原因。土地利用规划的龙头、管控 相似文献
367.
According to data obtained in the Bering Sea during the 4th Chinese National Arctic Research Expedition, the distribution of dissolved oxygen(DO) was studied, causes of its maximum concentration were discussed, and the relationships between DO and other parameters, such as salinity, temperature, and chlorophyll a were analyzed. The results showed DO concentration ranged from 0.53 to 12.05 mg/L in the Bering Sea basin. The upper waters contained high concentrations and the maximum occurred at the depth range from 20 to 50 m. The DO concentration decreased rapidly when the depth was deeper than 200 m and reached the minimum at the depth range from 500 to 1 000 m, and then increased slowly with the depth increasing but still kept at a low level. On the shelf, the DO concentration ranged from 6.53 to 16.63 mg/L with a mean value of 10.75 mg/L, and showed a characteristic of decreasing from north to south. The DO concentration was higher in the area between the Bering Sea and Lawrence Island and was lower in the southeast and southwest of Lawrence Island at the latitude of 62°N. The formation of maximum DO concentration was concerned with phytoplankton photosynthesis and formation of the themocline. To the south of Sta. B07 in the Bering Sea basin, the oxygen produced by photosynthesis permeated to the deeper water and the themocline made it difficult to exchange vertically, and to the north of Sta. B07, the maximum DO concentration occurred above the themocline due to phytoplankton activities. On the shelf, the oxygen produced by phytoplankton photosynthesis gathered at the bottom of the thermocline and formed the DO maximum concentration. In the Bering Sea basin, the DO and salinity showed a weak negative correlation(r=0.40) when the salinity was lower than 33.1, a significant negative correlation(r=0.92) when the salinity ranged from 33.1 to 33.7, and an irregular reversed parabola(r=0.95) when the salinity was greater than 33.7. 相似文献
368.
Types and Causes of Debris Flow Damage to Drainage Channels in the Wenchuan Earthquake Area 总被引:3,自引:1,他引:2
Debris flows are among the most common geological disasters in China,and have been particularly frequent in Sichuan Province since the Wenchuan earthquake on 12 May 2008.The construction of debris flow drainage channels is a countermeasure used to distribute debris flow fans,and these channels play a critical role in the mitigation and prevention of damage resulting from debris flows.Under field conditions,the useful life of drainage channels can be greatly shortened as a result of strong abrasions to the drainage structure caused by the debris flow.Field investigations have shown that the types of damage to drainage channels include(a) erosion caused by hyper-concentrated silt flow,(b) impact fractures and foundation scour at the groundsills of the drainage channel,(c) destruction of the drainage channel outlet,and(d) destruction of the drainage channel caused by debris flow abrasion.In addition,based on the destruction of the drainage channel during the debris flow drainage process,a new type of drainage channel with energy dissipation components was proposed and applied in a steep,narrow gully for debris flow mitigation.Moreover,design and engineering repair recommendations for drainage channels are provided as a reference for repairing the damage to the channel.The results can provide an important reference for the effective repair and optimal design of drainage channels. 相似文献
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1引言
自动气象站是大气探测地基系统的重要组成部分,更是开展精细化预报所不可缺少的气象要素源。实施加密观测的自动气象站由于网格距的需要而分布在不同的地理位置和气候环境中,在实际运行过程中很容易遭受雷电的侵袭。本文通过调研雷击实例,指出雷击原因,比照防雷设计规范和运用电磁兼容的原理提出改进措施。 相似文献
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