非开挖管道翻衬修复技术用树脂的研究

本课题针对非开挖管道翻衬修复技术用树脂进行了设计,根据管状织物织造工艺、翻衬修复管道工艺对树脂的要求,及DSC扫描结果、等温和动态黏度变化试验的实验结果进行分析,选择合理树脂的配方;通过手糊方法使得涂层织物与树脂体系进行复合,对聚氨酯树脂与织物和金属粘结机理进行分析。并对树脂体系与金属粘结强度进行测试,确定聚氨酯树脂与金属管壁粘结性能,为今后将非开挖管道翻衬修复技术应用到具体施工时,选择合适的树脂提供理论依据和操作方案。     

Contribution to diffuse gamma-rays in the Galactic Centre region from unresolved millisecond pulsars

Diffuse gamma-rays in the Galactic Centre region have been studied. We propose that there exists a population of millisecond pulsars in the Galactic Centre, which emit GeV gamma-rays through synchrotron-curvature radiation as predicted by outer gap models. These GeV gamma-rays from unresolved millisecond pulsars probably contribute to the diffuse gamma-ray spectrum detected by EGRET which displays a break at a few GeV. We have used a Monte Carlo method to obtain simulated samples of millisecond pulsars in the Galactic Centre region covered by EGRET  (∼ 15)  according to the different period and magnetic field distributions from observed millisecond pulsars in the Galactic field and globular clusters, and superposed their synchrotron-curvature spectra to derive the total GeV flux. Our simulated results suggest that there probably exist about 6000 unresolved millisecond pulsars in the region of angular resolution of EGRET, the emissions of which could contribute significantly to the observed diffuse gamma-rays in the Galactic Centre.     

Hydrogeological problems for the rehabilitation and re-utilisation of the water resources of the mining area of Gavorrano (Italy)

The paper describes the hydrogeological problems linked to the rehabilitation and re-utilisation of the water resources of the mining area of Gavorrano (Tuscany, Italy). It shows how the geological settings of the area control the water quality, chemistry and discharge. The results of the studies and the recent situations concerning circulation, quality and discharge of the mine water are reported, with particular reference to the effects of the controlled water rebound and the complex measures necessary for the dewatering stoppage. Water rebound is analysed on the basis of available historical and recent data for its hydrodynamic influence and the consequences on water resources restoration. Different uses and possible actions are proposed, taking into account thermal, chemical and discharge characteristics as well as local planning objectives.