一种新型直流屏蓄电池监控系统

传统的直流屏均采用对蓄电池组进行整体充电的方式，通过主充、浮充和均充三种方式对蓄电池组时行充电。长期运行在这种方式下，容易造成某些蓄电池的过早损坏，从而影响整个直流屏的稳定工作。本文针对传统直流屏蓄电池监控方式的不足，提出了一种新型直流屏的设计方案。在该方案中，为能够最大程序地满足蓄电池个体差异的要求，采用了对直流屏蓄电池进行单个充电的方法，即为每个蓄电池设计配置一个单元控制模块，负责该蓄电池的充放电过程的监控。另外调协一个总控制模块负责整个直流的控制及显示工作。各个控制模块之间通过485总线与Modbus协议组成一个总线型控制系统。     

Gray physical interference model based link scheduling algorithms

To improve the concurrent data transmission capability of wireless multi-hop networks,this paper proposes adopting a gray physical interference model instead of using the threshold physical interference model.The model allows non-ideal links to be involved in scheduling,under the premise of not affecting the quality of existing transmission links.In addition,we design two greedy algorithms to schedule more links with SINR values located in the transition region.The results show that a gray physical interference model is more accurate than a threshold physical interference one,the concurrent transmission capability of a network based on the gray physical interference model is significantly increased,and network throughput is increased by 20%.     

Development of highway constructing technology in the permafrost region on the Qinghai-Tibet plateau

The Qinghai-Tibet Highway passes through the Qinghai-Tibet plateau hinterland from north to south, from Kunlun Mountain to Tanggula Mountain. The average altitude is above 4500 m and permafrost covers more than 700 km length of area with high elevation and high temperature. The climate of the plateau is capricious and the surroundings along the road are bad, where the mean annual atmosphere temperature is -2 to -7℃ and the oxygen content is inadequate, which is less than 50% of the sea level, while the solar radiation is higher than 3600 kJ/m2. The basic characteristics of the plateau surroundings are the permafrost, coldness with litter oxygen, and fragile ecosystem. As the air temperature warms all over the world, the permafrost on the plateau responds quickly. The average temperature of permafrost is up by 0.2―0.3℃ in recent 20 years, and the island-permafrost dwindles with a high rate, and the high temperature permafrost degrades quickly, and the temperature of the low temperature permafrost increases remarkably. These gradually cause the highway engineering diseases in the permafrost region. The Qinghai-Tibet highway has experienced much maintenance and rebuilding for 50 years after it was built, and the continual observation and investigation have been made for more than 30 years. This road is the longest test engineering for permafrost research work in China. It is no doubt that it is also the greatest engineering project in plateau permafrost region. The Ministry of Communication in China initiated the research project "Research on a series of technologies for highway constructing in the permafrost regions" in 2002, which was to meet the challenges from the effect of climatic warming on the permafrost. The project systematically studied the permafrost engineering theories, methods for survey and design, engineering stabilization measures, preventing of the road disasters and maintaining, environment protection and the techniques to prolong the road engineering life in the cold surroundings with high altitude and less oxygen. This article describes a series of technologies for highway constructing according to the special surroundings in the plateau, including some innovative achievements and the research and development of permafrost engineering.     

弱透水层基坑降水实例分析

通过对基坑降水工程实例的现象及成因分析,提出弱透水层滞后疏干现象,并提出了在降水工程中合理应用的建议.