科创中国

随着石家庄市城市规模的扩大,越来越多的城市水文环境问题日益突出.在分析石家庄市目前水文环境的基础上,提出城市面临的水文问题:城市化进程的加快,对降水量、地下水位、灾害性天气、地表水环境、地下水水质等一系列水文参数产生影响,根据石家庄城市水文的特点,探讨其变化规律并采取相应的解决对策,对城市经济发展有重要意义.

简述流域水文模型的发展历程,介绍了集总式水文模型和分布式水文模型的概念和主要特点.在分析目前国内外分布式水文模型方面的研究现状的基础上,对国、内外具代表性的分布式模型进行对比,提出了分布式水文模型的分类及各自的特点,研究方面存在的问题和面临的挑战,指出了今后分布式水文模型的发展重点和方向.建议今后水文学界应在重视理论研究和实验研究的同时,积极开展分布式水文模型的应用研究.

石家庄市冶河灌区续建配套与节水改造工程项目自1998年立项以来,累计完成投资2.0亿元,改善了工程状况,提高用水效率,保障了区域粮食安全,促进了农业发展,拉动了地方经济.取得了良好的经济、社会和生态环境效益.随着国家对灌区投入的增加,冶河灌区将为夯实农业发展的水利基础方面做出更大贡献.

通过对渠家大院院落空间的调查研究,将院落单元作为渠家大院空间形态的构成要素,探究渠家大院的空间形态.通过对该院落空间的平面、立面和微观营造模式进行研究,深入地分析了该院落空间的布局特点、空间意向与营造理念,最终为读者解读了渠家大院空间系统的成长规律,进而揭示了渠家大院院落空间组织的方式与机制,有助对晋中城市民居营造理念与发展趋势有更好的把握.

Lightweight design requires an accurate life prediction for structures and components under service loading histories. However, predicted life with the existing methods seems too conservative in some cases, leading to a heavy structure. Because these methods are established on the basis that load cycles would only cause fatigue damage, ignore the strengthening effect of loads. Based on Palmgren-Miner Rule(PMR), this paper introduces a new method for fatigue life prediction under service loadings by taking into account the strengthening effect of loads below the fatigue limit. In this method, the service loadings are classified into three categories: damaging load, strengthening load and none-effect load, and the process for fatigue life prediction is divided into two stages: stage I and stage II, according to the best strengthening number of cycles. During stage I, fatigue damage is calculated considering both the strengthening and damaging effect of load cycles. While during stage II, only the damaging effect is considered. To validate this method, fatigue lives of automobile half shaft and torsion beam rear axle are calculated based on the new method and traditional methods, such as PMR and Modified Miner Rule(MMR), and fatigue tests of the two components are conducted under service loading histories. The tests results show that the percentage errors of the predicted life with the new method to mean life of tests for the two components are –3.78% and –1.76% separately, much lesser than that with PMR and MMR. By considering the strengthening effect of loads below the fatigue limit, the new method can significantly improve the accuracy for fatigue life prediction. Thus lightweight design can be fully realized in the design stage.

目的:观察长脉冲1064nmNd:YAG激光治疗婴幼儿皮肤血管瘤临床疗效,并探讨影响疗效的相关因素.方法:应用长脉冲1064nmNd:YAG激光治疗婴幼儿皮肤血管瘤215例,其中鲜红斑痣19例,草莓状血管瘤179例,混合型血管瘤17例.分析其疗效与病变类型、瘤体大小、病变部位及治疗次数的关系.结果:215例患儿中治愈133例,显效67例.有效8例.无效7例,痊愈率和有效率分别为61.9%和93.1%.疗效与血管瘤的病变类型、瘤体的大小以及治疗次数有关,但与其病变部位无明显相关性.治疗后暂时性色素沉着、暂时性色素减退、浅表性瘢痕、头部毛发减少或消失的发生率分别为48.8%、8.3%、4.6%和3.7%.结论:长脉冲1064nmNd:YAG激光治疗婴幼儿皮肤血管瘤疗效好,安全性较高,不良反应轻,可在临床上推广使用.

During hard cutting process there is severe thermodynamic coupling effect between cutting tool and workpiece, which causes quenching effect on finished surfaces under certain conditions. However, material phase transformation mechanism of heat treatment in cutting process is different from the one in traditional process, which leads to changes of the formation mechanism of damaged layer on machined workpiece surface. This paper researches on the generation mechanism of damaged layer on machined surface in the process of PCBN tool hard cutting hardened steel Cr12 Mo V. Rules of temperature change on machined surface and subsurface are got by means of finite element simulation. In phase transformation temperature experiments rapid transformation instrument is employed, and the effect of quenching under cutting conditions on generation of damaged layer is revealed. Based on that, the phase transformation points of temperature under cutting conditions are determined. By experiment, the effects of cutting speed and tool wear on white layer thickness in damaged layer are revealed. The temperature distribution law of third deformation zone is got by establishing the numerical prediction model, and thickness of white layer in damaged layer is predicted, taking the tool wear effect into consideration. The experimental results show that the model prediction is accurate, and the establishment of prediction model provides a reference for wise selection of parameters in precise hard cutting process. For the machining process with high demanding on surface integrity, the generation of damaged layer on machined surface can be controlled precisely by using the prediction model.

针对当前交叉口信号灯模糊控制器结构参数固定的缺陷,提出了一种新的分级模糊控制器用于交叉路口交通流的控制与优化,该控制器能有效地减少规则数,易于提取模糊规则,能够显著改善交叉路口的通行能力.仿真实验结果证明该模型是有效的.

水文信息化是近年来水文行业在水文事业发展和现代化建设过程中频繁提及和关注的一个新课题.采用现代信息技术使公众及时准确地了解水文信息,成为水文管理发展的新趋势.WebGIS(网络地理信息系统)是在地理信息技术和互联网技术支持下发展起来的,代表了GIS的发展方向.建立WebGIS支持下的实时水文信息查询系统,实现水文信息的直观化、图像化发布,为各级防汛部门提供实时、准确、权威的水文信息查询、统计和分析服务,从而提高各相关部门的办公效率和服务质量、降低管理成本.详细介绍了基于WebGIS的衡水水文信息查询系统的设计与实现方法.

依据故障树分析法(VIA)原理,对城市轨道交通车辆维修的安全故障因素进行了分析.城市轨道交通车辆维修的工艺过程存在着安全"风险累积"效应;维修后车辆的营运过程存在着"风险扩散"效应.在分析目前城市轨道交通车辆维修面临挑战的基础上,提出了风险应急和风险控制的相应对策.