基于调度规则的水库群供水能力与风险分析

鉴于水库群供水风险指标体系的复杂结构和层次特征,本文采用层次分析法确定不同用水户各风险指标的权重,以供水风险最小为目标函数,构建水库群供水优化调度模型,提出了探讨水库群供水能力与风险分析的一般框架。即主要由以下4部分构成：（1）来水、用水资料的随机模拟生成;（2）水库群供水风险综合评价指标的计算;（3）聚合水库调度图与共同供水任务分配过程的优化;（4）共同供水任务分配规则的拟定。通过调整主要用水户的需水额度,分析水库群供水量与供水风险之间的关系,确定允许风险范围内的水库群供水能力。以中国北方某并联供水水库群为例,对调度规则控制下水库群供水能力与相应风险进行了分析,验证了所提框架的可行性与合理性。     

不同沟垄集雨方式对旱地燕麦耗水强度及产量的影响

沟垄覆膜集雨技术在旱区农业中的显著节水增产作用,使其在我国西北半干旱农业区得到了广泛地应用。为了研究适宜于燕麦的沟垄集雨方式,分析其耗水规律,丰富沟垄集雨模型,设计了4个处理:T1—平地种植,T2—沟垄不覆膜不供水种植,T3—沟垄覆膜不供水种植,T4—平地充分供水种植。结果表明:(1)在燕麦的主要生育阶段,除T4处理之外,T1处理的耗水量要高于T2和T3处理;(2)T3处理显著地增加了耕作层0～30cm剖面的土壤水分,达到6.93mm,而T1处理土壤各剖面的水分消耗量最高;(3)T4处理的产量最高为1 854kg/hm2,T3处理的产量为1 611.2kg/hm2,T4较T3高242.8kg/hm2。而在不供水的各处理之中(T1、T2、T3),T3较T1和T2分别增产28.1%和27.8%;(4)T4处理各产量构成为各处理中最高,T3处理显著降低了燕麦的千粒重,其值仅为13.9g,其余主要指标均显著高于T1处理。     

坡面流阻力规律试验研究

通过实验室人工隆雨水槽试验，初步研究了坡面浅层均匀流及由降雨形成的浅层沿程变量流的流动阻力规律，根据试验中观察到的物理现象及对实测资料的分析，进一步明确了坡面浅层水汉与一般明渠流水力特性的差别，揭示了降雨、坡度和表面粗糙度对浅层流流动特性的影响，提出了“伪层流”的概念，根据实测资料建立了不同流区的Ｄarcy-Weisbach阻力参数f的定量关系式，研究成果可用于坡面流汇流计算及土壤侵蚀、产沙模拟等生产实践。     

Does the Exchange Rate Respond to Monetary Policy in Mexico? Solving an Exchange Rate Puzzle in Emerging Markets

This paper argues that the null or weak response of emerging market currencies to domestic monetary policy documented in the literature is the result of wide event windows. An event study with intraday data for Mexico shows that an unanticipated tightening appreciates the currency and flattens the yield curve, consistent with the evidence for advanced economies. With daily event windows, however, only the yield curve responds to monetary policy. Noise in daily exchange rate returns explains the lack of response of the currency. Such noise gives rise to a bias that declines after controlling for potential omitted variables.     

The 1932 Federal Reserve Open-Market Purchases as a Precedent for Quantitative Easing

The $1 billion open-market operation conducted by the Federal Reserve, at the height of the Great Depression, was a successful precedent to the recent Quantitative Easing (QE) programs. The 1932 program entailed large purchases of medium- and long-term securities over a 4-month period. An event study analysis indicates that the program dramatically lowered medium- and long-term Treasury yields. A segmented markets model is used to analyze the effects of the open-market purchases on the economy. A significant degree of financial market segmentation is estimated, and partly explains the observed upturn in output growth. Had the Federal Reserve continued its operations and used the announcement strategy used in QE1, the Great Contraction could have been attenuated earlier. Our historical analysis suggests that the Federal Reserve in 2008 had a good predecessor to its actions.     

EUROSEM模型对晋西黄绵土坡面侵蚀过程的模拟应用

晋西黄绵土坡面因其土壤、降雨等条件极易造成严重水土流失,本文基于不同坡长(2、3、4m)与雨强(60、90、120 mm/h)组合方式下的野外人工模拟降雨试验,应用EUROSEM模型对坡面径流侵蚀过程及产流产沙总量进行模拟,通过对比分析模拟值与实测值,评价该模型对晋西黄绵土坡面土壤侵蚀过程的模拟效果及在该区的适用性.结...