Bi-level programming model for reconstruction of urban branch road network

Considering the decision-making variables of the capacities of branch roads and the optimization targets of lowering the saturation of arterial roads and the reconstruction expense of branch roads, the bi-level programming model for reconstructing the branch roads was set up. The upper level model was for determining the enlarged capacities of the branch roads, and the lower level model was for calculating the flows of road sections via the user equilibrium traffic assignment method. The genetic algorithm for solving the bi-level model was designed to obtain the reconstruction capacities of the branch roads. The results show that by the bi-level model and its algorithm, the optimum scheme of urban branch roads reconstruction can be gained, which reduces the saturation of arterial roads apparently, and alleviates traffic congestion. In the data analysis the arterial saturation decreases from 1.100 to 0.996, which verifies the micro-circulation transportation’s function of urban branch road network. Foundation item: Project(2006CB705507) supported by the National Basic Research and Development Program of China; Project(20060533036) supported by the Specialized Research Foundation for the Doctoral Program of Higher Education of China     

Effects of main factors on remedying northern landscaping water by hybrid ecological filter

Natural zeolite and coal cinder were layered as main packing medium of the ecological filter instead of traditional filling to remedy the static lake water in Northern China.The ecological filter was running in a combined upward and downward flow mode.Dynamic experiments were carried out to study the effects of retention time and ambient temperature on pollutants’ removal efficiency of the hybrid ecological filter.The function of plant was also studied by contrast test.It is showed that the removal efficiencies of NH4+-N and TP are increased when the retention time is changed from 1 h to 2 h and 4 h,but the removal efficiency of TN is decreased,the removal efficiency of NH4+-N is increased from 91.5% to 98% and that of TP is increased from 31.8% to 52.5%.When the temperature declines,the temporal removal efficiency of NH4+-N is reduced,but the removal efficiency of 24 h and 48 h is remained.The removal efficiency of TP after 24 h and 48 h is decreased when the temperature declines evidently.The retention time plays an important role in NH4+-N and TP removal,and the ambient temperature is significant for TP removal.The plant favors for TP and organic matter removal but has little effect on TN removal.     

江西省农业旱情预测模型的建立与应用

根据农业用地的不同性质分别建立旱地缺墒模型,灌溉水田、水浇地、菜地与望天田缺水度模型,并据此建立江西省农业旱情预测模型,对江西省农业旱情进行预测.为科学抗旱和减少旱灾损失提供依据和指导.     

Influence of preload discreteness on air-operated separation process of low-shock separation device

To investigate the influence of design parameters on the performance of separation device,the structure and air-operated test of a low-shock separation device are introduced and analyzed in this paper.According to the law of energy conservation and aerodynamics,a mathematical model is built.Because the preload used to ensure the connection reliability has the discreteness,which will influence the separation process,the influence of preload discreteness on the air-operated separation process is simulated and tested.Simulation results are consistent with the experimental results.It is shown that the change of preload has an obvious influence on the separation process.The study is useful for the design and optimization of separation device.     

Prevention and forecasting of rock burst hazards in coal mines

Rock bursts signify extreme behavior in coal mine strata and severely threaten the safety of the lives of miners, as well as the effectiveness and productivity of miners. In our study, an elastic-plastic-brittle model for the deformation and failure of coal/rock was established through theoretical analyses, laboratory experiments and field testing, simulation and other means, which perfectly predict sudden and delayed rock bursts. Based on electromagnetic emission (EME), acoustic emission (AE) and microseism (MS) effects in the process from deformation until impact rupture of coal-rock combination samples, a multi-parameter identification of premonitory technology was formed, largely depending on these three forms of emission. Thus a system of classification for forecasting rock bursts in space and time was established. We have presented the intensity weakening theory for rock bursts and a strong-soft-strong (3S) structural model for controlling the impact on rock surrounding roadways, with the objective of laying a theoretical foundation and establishing references for parameters for the weakening control of rock bursts. For the purpose of prevention, key technical parameters of directional hydraulic fracturing are revealed. Based on these results, as well as those from deep-hole controlled blasting in coal seams and rock, integrated control techniques were established and anti-impact hydraulic props, suitable for roadways subject to hazards from rockbursts have also been developed. These technologies have been widely used in most coal mines in China, subject to these hazards and have achieved remarkable economic and social benefits.     

Improvements in seismic event locations in a deep western U.S. coal mine using tomographic velocity models and an evolutionary search algorithm

Methods of improving seismic event locations were investigated as part of a research study aimed at reducing ground control safety hazards. Seismic event waveforms collected with a 23-station three-dimensional sensor array during longwall coal mining provide the data set used in the analyses. A spatially variable seismic velocity model is constructed using seismic event sources in a passive tomographic method. The resulting three-dimensional velocity model is used to relocate seismic event positions. An evolutionary optimization algorithm is implemented and used in both the velocity model development and in seeking improved event location solutions. Results obtained using the different velocity models are compared. The combination of the tomographic velocity model development and evolutionary search algorithm provides improvement to the event locations.     

南宋初期山水画生态环境之考察

中国绘画史上许多重要风格的产生常常与其所处的政治、经济、文化环境的某些变化产生紧密联系,即艺术风格的转变不仅仅是其内心自律性的产物,更与具体的社会历史情境有关。南宋由政治巨变带来的社会动荡,在社会生活的方方面面均有反映。本文通过对宋室南渡后南宋社会生态环境的考察,了解南宋山水画赖以存在和发展的土壤,说明南宋山水画之清远雅洁、雅俗通融的特征与画家们的生存环境、相关赞助群体以及地域、文化变迁之间有着不可分割的密切关系。     

热量表的热量计量及传感器选型

以热量表热量计量原理为基础,介绍了几种常用的热量计量方法,分析比较了各自的优缺点,详细讨论了具有k系数补偿功能的热量计量方法——k系数补偿法,该方法实现了k系数的温度和压力在线补偿,因而具有较高的精度．还介绍了热量表测量系统的构成。     

奥运中心区超标降雨积水风险分析及对策研究

随着城市的发展,城市积水造成了越来越严重的问题.解决问题的关键就是分析超标降雨下的城市积水风险,以指导近期应急排水预案以及远景城市雨水系统改造方案的制定.由于北京市降雨量年内分配很不均匀,汛期暴雨又多表现为局地短历时的大暴雨甚至特大暴雨,造成城市道路（特别是立交桥区）积水问题频发,严重影响城市交通.在此背景下,从保障奥运安全召开的角度出发,以奥运中心区为研究对象,收集整理奥运中心区雨水系统各组成部分相关资料,建立奥运中心区雨水系统数据库,建立奥运中心区雨水系统模型,对超标降雨条件下奥运中心区的可能积水风险进行了分析,并以此为基础进行对策研究和实施效果评价.