溪洛渡水电站泄洪系统运行特点

溪洛渡水电站具有“窄河谷、高拱坝、巨泄量”的特点,泄洪建筑物由7个泄洪表孔、8个泄洪深孔以及4条泄洪洞组成.泄洪系统按照“分散泄洪、分区消能”的原则布置.坝身泄洪采用表孔下跌式、深孔上翘式布置,两股水舌在空中碰撞后跌入水垫塘内紊动消能.正常运行方式下,优先开启坝身泄洪深孔,后开启泄洪表孔,泄洪洞宜在坝身泄流能力不足时参与泄洪.     

横观各向同性饱和两相介质弹塑性波动问题研究

针对横观各向同性饱和两相介质的弹塑性波动问题,建立了基于SMP 破坏准则的横观各向同性饱和两相介质弹塑性动力本构模型,并建立了横观各向同性饱和两相介质弹塑性波动问题求解的时域显式有限元方法。基于上述本构模型与时域显式有限元方法进行了横观各向同性饱和两相介质弹塑性波动问题的研究。研究结果表明：横观各向同性饱和两相介质的弹塑性动力反应与其弹性动力反应有较为显著的差异,表现在前者的反应峰值相对于后者有较为明显的增大,同时二者反应时程的波形也有较大的差异。数值计算工作同时表明,时域显式有限元方法是进行横观各向同性     

基于RVA法的河流生态需水量研究

以河流生态水文变化的指标体系（Indicator of Hydrologic Alteration,IHA）为基础,立足整体河流水文情势的流量谱系,采用变异性范围法（Range of Variability Approach,RVA）,进行基于长系列历史流量资料的河流生态需水量估算,并以山西省5条较大河流的生态敏感断面为对象进行研究。结果表明,利用本方法估算的结果是合理的,可为河流生态需水量的估算和水资源的可持续开发利用提供科学依据。     

黏性土的抗剪强度特性试验研究

利用环剪仪针对塑性指数不同的3种黏性土,在不同的固结状态下进行了较系统的试验研究,探讨了大变形黏土的抗剪强度变化规律,分析了残余强度的影响因素。试验结果表明：本试验所采用的环剪仪无论对于粉质黏土还是黏土均具有良好的稳定性,测试精度高,因此能够保证试验结果的准确性;对于塑性指数不大的粉质黏土,应力历史对其抗剪强度的影响并不显著;对于塑性指数较大的黏土,应力历史对残余强度没有影响,而峰值强度随着超固结比的增大而增大,最终接近粉质黏土的峰值强度;塑性指数是影响残余强度非常重要的因素,随着塑性指数的增大,残余强度显著降低;黏性土剪切沉降曲线的类型与塑性指数和超固结比有关。     

基于SPA和信息熵的可变模糊集水质评价方法

针对水环境质量动态多变性、不确定性和模糊性的特点,采用集对分析方法计算水质样本与水质评价等级之间的联系度,运用信息熵确定评价指标的权重值,进而建立基于可变模糊集的水质定量评价模型,以5级评判为原则,对以往利用集对势评判水质等级的方法进行了改进。实例评价结果与综合指数法、灰色关联法评价结果对比,验证了该方法的实用性和有效性,其评价结果能够反映研究对象的真实状况。     

夏特水电站排沙漏斗模型优化

通过对夏特水电站引水排沙设施双排沙漏斗进行水力学模型试验,将原设计方案的漏斗直径、悬板高度、排沙底孔、底孔偏心距和进口涵洞等结构的关键尺寸进行了优化。上游干渠段在通过设计流量112.8 m3/s时,设计的排沙漏斗悬板高度不满足要求,导致干渠中水深过大,原设计方案的边墙高度不能满足过流要求。提出采用降低悬板高度、增大偏心距等方法来满足工程的要求。试验结果表明,在降低悬板高度、改变偏心距之后,干渠中水深明显降低,并且两个排沙漏斗中都易形成稳定的空气涡,提高了排沙率。     

小云峰水电站右岸副坝渗水处理

小云峰水电站右岸副坝为混凝土重力式自由溢流坝。坝基岩质坚硬,裂隙较发育。推荐处理设计方案为:在溢流坝坝面以下2m采用伸缩性(柔性)化灌材料(聚氨酯类)灌注满,使坝缝内的水不从坝面渗出,同时保证一定的抗冻深度,排水孔、灌浆孔、排气孔均采用斜孔,避免破坏止水。     

The optimal retrieval of ocean color constituent concentrations based on the variational method

In this paper, a new approach to the optimal retrieval of the ocean color based on the variational method is developed by setting up a rational target functional combining with the Broydor Fletcher, Goldfarb, Shanno (BFGS) optimal algorithm. The numerical tests and the exemplary retrievals are carried out and compared with the statistical retrievals and the optimal retrievals based on the genetic algorithm. The results show that this approach enjoys a higher accuracy as compared to the statistical method and a higher efficiency as compared to the genetic algorithm. The optimal retrieval method presented in this paper provides a new idea for the ocean color inversion and could also be used as a reference for the direct assimilation of the satellite data into the ecological models.     

Modeling and analysis of effects of precipitation and vegetation coverage on runoff and sediment yield in Jinsha River Basin

This paper focuses on the effects of precipitation and vegetation coverage on runoff and sediment yield in the Jinsha River Basin. Results of regression analysis were taken as input variables to investigate the applicability of the adaptive network-based fuzzy inference system (ANFIS) to simulating annual runoff and sediment yield. Correlation analysis indicates that runoff and sediment yield are positively correlated with the precipitation indices, while negatively correlated with the vegetation indices. Furthermore, the results of stepwise regression show that annual precipitation is the most important factor influencing the variation of runoff, followed by forest coverage, and their contributions to the variation of runoff are 69.8% and 17.3%, respectively. For sediment yield, rainfall erosivity is the most important factor, followed by forest coverage, and their contributions to the variation of sediment yield are 49.3% and 24.2%, respectively. The ANFIS model is of high precision in runoff forecasting, with a relative error of less than 5%, but of poor precision in sediment yield forecasting, indicating that precipitation and vegetation coverage can explain only part of the variation of sediment yield, and that other impact factors, such as human activities, should be sufficiently considered as well.