延安红色旅游高质量发展推进路径研究

红色旅游作为一项政治和文化工程,具备政治、经济和社会三维属性。以促进延安红色旅游高质量发展为目的,采用质性研究方法分析延安红色旅游发展基础、典型模式及存在问题,从传承红色文化时代基因、加强红色文化影响力度、创新壮大红色文化旅游业态、提振红色文化消费活力四个维度,构建延安红色旅游高质量发展路径。研究结果表明,推动延安红色旅游高质量发展,有利于弘扬中国革命精神、加强政治生态建设、凝结中华民族史观,激励人们继续为实现中国梦而努力奋斗。

Effect of platform temperature on microstructure and corrosion resistance of selective laser melted Al-Mg-Sc alloy plate

The Al-3.40Mg-1.08Sc alloy plates were manufactured by selective laser melting(SLM) at platform temperatures of 35 ℃ and 200 ℃, respectively, and the corrosion performance of them was studied along height direction. The results show that the corrosion resistance of the alloy plate built at platform temperature of 35 ℃ along height direction is basically the same due to a uniform microstructure;While the corrosion resistance of the alloy plate built at platform temperature of 200 ℃ along height direction is different. The evolution of microstructure and the distribution of secondary phases are investigated, and the results show that the Cu-rich phases in alloy play a key role on corrosion performance. At higher platform temperature, the cooling rate is relative slow and a certain degree of in situ ageing leads to the significantly different distribution of Cu-rich phases along grain boundary. Specimens built at the platform temperature of 200 ℃ are inclined to locate at the crossed grain boundary, rather than continuous segregation of Cu-rich phases along grain boundary that is built at platform temperature of 35 ℃. Therefore, the corrosion resistance of Al-3.40Mg-1.08Sc alloy plate manufactured at platform temperature of 200 ℃ is higher, and presents a gradually decreasing trend along height direction.

排污权转移视角下跨界水污染补偿标准研究

跨界水污染问题已成为我国当前流域间竞争性矛盾的焦点,为此通过建立跨界水污染补偿机制解决此问题备受各方关注,其中关键是补偿标准的确定。以河南省辖海河流域焦作市跨界水污染为研究对象,基于排污权转移视角,运用灰色预测模型得出理论排污量、实际排污量与理论排污量之差即为转移排污量;通过计算转移排污量的污水治理成本和机会成本来量化跨界水污染补偿标准的上下限。结果表明:污水治理成本和机会成本计算出的结果相差很大,具体补偿标准的确定需考虑补偿主客体的收益和损失才更加科学合理。补偿标准的上下限能为通过协商和谈判确定具体数额的补偿标准提供一定的借鉴和参考。

面向混频数据的时滞GM(1,N)模型

采样频率不同、间距不等的混频数据背景下,考虑时滞是系统要素间因果作用的常见现象,提出含时滞参数的混频GM(1,N)建模方法。根据时滞特征不同,将模型划分为两类:同步推移型时滞GM(1,N)模型和累积型时滞GM(1,N)模型。同步推移型用于表征时滞长度固定但起始时间不确定、具有管道延迟性质的时滞关系。累积型用于表征时滞长度不确定、因果效应逐步叠加的时滞关系。将指数Almon函数作为时滞分布函数,该函数可完全由数据驱动生成递增、递减、S型、U型、钟型等多种形态,有助于挖掘混频数据中的时滞信息。数值分析的结果验证了模型的有效性。模型对于存在低频小样本数据的混频时滞系统具有很强的适用性。