高瓦斯矿井复合顶板炮采工作面瓦斯治理

结合该矿采煤工作面实际情况,阐述了高瓦斯矿井复合顶板炮采工作面的关键技术处理措施,保证了煤炭的安全生产。解决了高瓦斯矿井复合顶板炮采工作面瓦斯治理难的问题。     

鱼雷捷联系统动基座精对准的卡尔曼滤波法

为解决鱼雷捷联系统的初始对准，提出了失准角及陀螺随机常值漂移快速估计方法，经数字仿真，对缩短初始对准时间，提高初始对准精度有较好的效果。     

渭河流域水利水保措施减水减沙效益初步分析

截止1989年底,渭河流域共有水库361座,塘坝2666座,引水有效灌溉面积40.4万公顷,治理总面积8136km~2,治理度17.1％。以1970年为效益计算起始年,并将全流域划分为18个片,分别采用水文法和水保法计算1970～1989年间各项水利水保措施减水减沙量及综合减水减沙效益。水文法算得的综合减水效益为24.1％,减沙效益为30.6％;水保法算得的结果相应为29.9％和30.8％,两者相近。     

皇甫川流域水沙特性分析及其治理对策

作者对皇甫川流域从径流泥沙来源、水沙特性、水沙变化趋势等方面进行了较为深入地分析和研究，据此提出皇甫川流域近期治理方略是：以沟道坝系建设为切入点；积极推进林草植被建设；对砒砂岩地区实行大面积封禁治理。流域近期至2010年，治理的重点建议放在十里长川、沙圪堵至皇甫区间和沙圪堵以上的纳林川左岸。     

降雨衰减对移动卫星系统通信的影响及补偿

针对移动卫星系统的特点，分析了降雨引起的信号衰减的原因，给出了雨衰的计算方法。Ka波段一般用于移动通信业务，从分析结果上看该波段信号受降雨影响较大。提出几种补偿雨衰的方法，给出了上行功率控制法的系统原理图。     

塔里木河流域源流及干流水均衡分析

通过对塔里木河流域源流及干流的径流变化和水均衡分析 ,表明塔里木河源流来水基本稳定 ,由于源流灌区引水以及渗漏蒸发等损失加剧 ,干流水量存在减少趋势 ,并加剧了水量的时间分配不均 ,不利于干流农业的可持续发展和生态环境的维护与改善     

Some experimental findings in compression-after-impact (CAI) tests of CF/PEEK (APC-2) and conventional CF/epoxy flat plates

Compression-after-impact (CAI) tests have been conducted for quasi-isotropic thick plates with 48 plies by using the NASA method and on plates with 32 plies by using the SACMA method. Specimens are made of CF/PEEK (APC-2) and conventional CF/epoxy for the NASA plates and CF/epoxy for the SACMA plates. In the NASA CAI tests, the sequence of delamination buckling and its propagation is clearly revealed through various experimental techniques. One major technique is moiré topography, and the other is thermo-mechanical stress analysis with a high-accuracy infrared sensor. The arrest of delamination propagation just before catastrophic failure due to high fracture toughness is clearly captured by the moiré camera. This behavior provides good CAI values of CF/PEEK. The initial buckling properties of the delaminated region by the impact are then extensively discussed. Numerical predictions of initial buckling stress have been obtained by modelled geometry of the delaminated region simplified from its precise structure clarified by ultrasonic C-scanning. They agree fairly well with the experimental results. The in-plane stress distribution in the delaminated region before initial buckling is measured by an infrared stress graphic system. This compared favorably with finite element predictions. Two types of symmetric buckling modes with respect to the central plate surface, twin and single peak ones, are experimentally captured.     

水文学的研究方法与理论创新

回顾了水文学在其 30 0余年的形成和发展中曾出现过的若干引人入胜、富有启发性、对学科发展起着重要推动作用的研究成果 .论述了“假设”、“猜想”、“推理”、“比拟”、“综合”和“实验”等研究方法的运用在水文学理论创新中的重要作用 .     

Simulation of runoff and phosphorus transport in a Carpathian catchment,Slovakia

A comprehensive, GIS‐based modelling approach is developed to estimate runoff and phosphorus transport within a watershed at a daily time step. The approach relies on the use of GIS data for deriving major critical model parameters that exhibit distinct spatial variability over the catchment. Surface runoff is calculated by a modified rational method, which depends upon rainfall intensity, soil moisture status, slope, land‐use and soil characteristics. Phosphorus loading is estimated as a function of the runoff volume and the event mean concentration for different land use categories. A diffusive approximation method is used to trace runoff and phosphorus transport to the basin outlet. The modelling approach is tested in the Margecany catchment, Hornad River basin, Slovakia, to simulate runoff, phosphorus loading, and its transport on a daily time scale using data observed between 1995 and 2000. Satisfactory results of the hydrographs and phosphorus concentration at the basin outlet are obtained, though more efforts regarding the phosphorus cycling and its biochemical reactions need to be clarified by further research. Copyright © 2006 John Wiley & Sons, Ltd.     

近距离坚硬顶板薄煤层开采支护技术

近距离薄煤层在准备采煤工作面时的巷道掘进中,受上层残余压力的影响,矿压显现突出,采用常规的巷道支护方法不能有效控制矿压。文章根据大同煤矿集团公司晋华宫矿实际情况,介绍了关于近距离采空区下半煤巷掘进工艺、支护和工作面开采期间有效控制矿压的方法。