层次分析法在彩票抽奖方案选择中的应用

采用层次分析法对29种彩票抽奖方案进行排序,较为科学地解决了比较多种方案优劣程度的问题,得到了彩票抽奖方案选择问题的优化解.     

Meander hydrodynamics initiated by river restoration deflectors

River restoration projects have installed j‐hook deflectors along the outer bank of meander bends to reduce hydraulic erosion, and in this study we use a computational fluid dynamics (CFD) model to document how these deflectors initiate changes in meander hydrodynamics. We validated the CFD with streamwise and cross‐channel bankfull velocities from a 193° meander bend flume (inlet at 0°) with a fixed point bar and pool equilibrium bed but no j‐hooks, and then used the CFD to simulate changes to flow initiated by bank‐attached boulder j‐hooks (1^st attached at 70°, then a 2^nd at 160°). At bankfull and half bankfull flow the j‐hooks flattened transverse water surface slopes, formed backwater pools upstream of the boulders, and steepened longitudinal water slopes across the boulders and in the conveyance region off the mid‐channel boulder tip. Streamwise velocity and mass transport jets upstream of the j‐hooks were stilled, mid‐channel jets were initiated in the conveyance region, eddies with a cross‐channel axis formed below boulders, and eddies with a vertical axis were shed into wake zones downstream of the point bar and outer bank boulders. At half bankfull depth conveyance region flow cut toward the outer bank downstream of the j‐hook boulders and the secondary circulation cells were reshaped. At bankfull depth the j‐hook at 160° was needed to redirect bank‐impinging flow sent by the upstream j‐hook. The hooked boulder tip of both j‐hooks funneled surface flow into mid‐channel plunging jets, which reversed the secondary circulation cells and initiated 1 to 3 counter rotating cells through the entire meander. The main outer bank collision zone centered at 50° without the j‐hook was moved by the j‐hook to within and just beyond the 70° j‐hook boulder region, which displaced other mass transport zones downstream. J‐hooks re‐organized water surface slopes, streamwise and cross‐channel velocities, and mass transport patterns, to move shear stress from the outer bank and into the conveyance and mid‐channel zones at bankfull flow. At half bankfull flows a patch of high shear re‐attached to the outer bank below the downstream j‐hook. J‐hook geometry and placement within natural meanders can be analyzed with CFD models to help restoration teams reach design goals and understand hydraulic impacts. Copyright © 2011 John Wiley & Sons, Ltd.     

Coupled surface water–groundwater model and its application in the arid Shiyang River basin,China

The planning and management of water resources in the Shiyang River basin, China require a tool for assessing the impact of groundwater and stream use on water supply reliabilities and improving many environment‐related problems such as soil desertification induced by recent water‐related human activities. A coupled model, integrating rule‐based lumped surface water model and distributed three‐dimensional groundwater flow model, has been established to investigate surface water and groundwater management scenarios that may be designed to restore the deteriorated ecological environment of the downstream portion of the Shiyang River basin. More than 66% of the water level among 24 observation wells have simulation error less than 1·0 m. The overall trend of the temporal changes of simulated and observed surface runoff at the Caiqi gauging station remains almost the same. The calibration was considered satisfactory. Initial frameworks for water allocation, including agricultural water‐saving projects, water diversion within the basin and inter‐basin water transfer, reducing agricultural irrigation area and surface water use instead of groundwater exploitation at the downstream were figured out that would provide a rational use of water resources throughout the whole basin. Sixteen scenarios were modelled to find out the most appropriate management strategies. The results showed that in the two selected management options, the groundwater budget at the Minqin basin was about 1·4 × 10⁸ m³/a and the ecological environment would be improved significantly, but the deficit existed at the Wuwei basin and the number was about 0·8 × 10⁸ m³/a. Water demand for domestic, industry and urban green area would be met in the next 30 years, but the water shortage for meeting the demand of agricultural water use in the Shiyang River basin was about 2·2 × 10⁸ m³/a. It is suggested that more inter‐basin water transfer should be required to obtain sustainable water resource use in the Shiyang River basin. Copyright © 2009 John Wiley & Sons, Ltd.     

语义Web本体语言及OWL研究

面对Internet应用模式的变化和Web海量信息的冲击,Web信息个性化、智能化的研究不断深入.语义Web规划对当前的万维网进行扩展,期望用加入信息中的语义内容导航信息资源检索并提高网络服务的智能化,使机器自动与人协同工作.目前,虽然语义Web还是个理想模型,但将语义Web融入现有Web结构进行信息智能开发的初步努力已经展开.特别是随着对本体技术研究的日渐深入,OWL本体理论探索和应用开发逐渐受到广泛重视.     

基于整合理论的高校教师管理

整合理论实质就是对组织所拥有的资源进行优化配置,使其协调发展,产生最大效益.对于高校,教师是所拥有的不可缺少,最具有潜力的资源,这种资源所发挥的协同作用存在巨大的潜力.从整合理论的角度,分析了高校教师管理方面的整合问题,提出了高校教师管理过程中应该注意的问题.     

形变地球对不同驱动力的响应

地球形变位移场和重力场的时空变化无论在基础理论研究,还是在地理空间信息建设中都具有重要的意义.地球在各种力学机制的作用下产生了形变,形变又导致地球引力位的变化,即形变附加位或Euler引力位增量.基于矢量球函数的基本理论,讨论了引潮力、负载力和地表应力对地球形变和引力位增量的影响,给出了均匀不可压缩地球模型的Euler引力位增量的具体表达式和Love数的理论关系.可为地球形变的理论研究提供参考和依据.     

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Role of Sunspot and Sunspot-Group Rotation in Driving Sigmoidal Active Region Eruptions

We study active region NOAA 9684 (N06L285) which produced an X1.0/3B flare on November 4, 2001 associated with a fast CME (1810 km s⁻¹) and the largest proton event (31 700 pfu) in cycle 23. SOHO/MDI continuum image data show that a large leading sunspot rotated counter-clockwise around its umbral center for at least 4 days prior to the flare. Moreover, it is found from SOHO/MDI 96 m line-of-sight magnetograms that the systematic tilt angle of the bipolar active region, a proxy for writhe of magnetic fluxtubes, changed from a positive value to a negative one. This signifies a counter-clockwise rotation of the spot-group as a whole. Using vector magnetograms from Huairou Solar Observing Station (HSOS), we find that the twist of the active region magnetic fields is dominantly left handed (α_best = −0.03), and that the vertical current and current helicity are predominantly negative, and mostly distributed within the positive rotating sunspot. The active region exhibits a narrow inverse S-shaped H_α filament and soft X-ray sigmoid distributed along the magnetic neutral line. The portion of the filament which is most closely associated with the rotating sunspot disappeared on November 4, and the corresponding portion of the sigmoid was observed to erupt, producing the flare and initiating the fast CME and proton event. These results imply that the sunspot rotation is a primary driver of helicity production and injection into the corona. We suggest that the observed active region dynamics and subsequent filament and sigmoid eruption are driven by a kink instability which occurred due to a large amount of the helicity injection.