Experiment and mechanism investigation on advanced reburning for NOx reduction： influence of CO and temperature

Pulverized coal reburning, ammonia injection and advanced reburning in a pilot scale drop tube furnace were investigated. Premix of petroleum gas, air and NH3 were burned in a porous gas burner to generate the needed flue gas. Four kinds of pulverized coal were fed as reburning fuel at constant rate of 1g/min. The coal reburning process parameters including 15%～25% reburn heat input, temperature range from 1100 ℃ to 1400 ℃ and also the carbon in fly ash, coal fineness, reburn zone stoichiometric ratio, etc. were investigated. On the condition of 25% reburn heat input, maximum of 47% NO reduction with Yanzhou coal was obtained by pure coal reburning. Optimal temperature for reburning is about 1300 ℃ and fuel-rich stoichiometric ratio is essential; coal fineness can slightly enhance the reburning ability. The temperature window for ammonia injection is about 700 ℃～1100 ℃. CO can improve the NH3 ability at lower temperature. During advanced reburning, 72.9% NO reduction was measured. To achieve more than 70% NO reduction, Selective Non-catalytic NOx Reduction (SNCR) should need NH3/NO stoichiometric ratio larger than 5, while advanced reburning only uses common dose of ammonia as in conventional SNCR technology. Mechanism study shows the oxidization of CO can improve the decomposition of H2O, which will rich the radical pools igniting the whole reactions at lower temperatures.     

A two-step approach to investigate the effect of rating curve uncertainty in the Elbe decision support system

For river basin management, the reliability of the rating curves mainly depends on the accuracy and time period of the observed discharge and water level data. In the Elbe decision support system （DSS）, the rating curves are combined with the HEC-6 model to investigate the effects of river engineering measures on the Elbe River system. In such situations, the uncertainty originating from the HEC-6 model is of significant importance for the reliability of the rating curves and the corresponding DSS results. This paper proposes a two-step approach to analyze the uncertainty in the rating curves and propagate it into the Elbe DSS： analytic method and Latin Hypercube simulation. Via this approach the uncertainty and sensitivity of model outputs to input parameters are successfully investigated. The results show that the proposed approach is very efficient in investigating the effect of uncertainty and can play an important role in improving decision-making under uncertainty.     

运用化归数学思想,把握初中代数基本建构

化归思想是初中代数学习的重要思想,有助于学生完成代数基本建构。基于此,本文在分析化归数学思想内涵的基础上,结合代数问题解答例子从化归思想理解、运用和拓展三方面提出了初中代数教学运用化归思想的方法,为关注这一话题的人们提供参考。     

不确定输入时滞系统滑模控制的LMI方法

本文中我们考虑不确定输入时滞系统的滑模控制问题．通过作相应的变换将模型降阶．基于线性矩阵不等式方法给出了滑模控制器存在且使得系统渐近稳定的充分条件,并以线性矩阵不等式的形式给出结论．同时本文还给出了滑模控制器的简单设计方法．     

一种不确定离散时间系统的变结构控制

讨论了利用指数趋近律设计不确定离散变结构控制系统的问题,给出了改进的离散趋近律,得出了新的控制律,并证明了系统在此控制律下可以渐近趋于原点的性质,降低了系统的抖振,同时结合时延技术对干扰进行在线估计,抵消掉系统中的慢变不确定性.最后仿真结果证明了该方法的有效性.     

Examining the Decision to Talk with Family About Organ Donation: Applying the Theory of Motivated Information Management

Research on organ donation suggests a strong association between family discussions about the issue and final organ donor status. However, very few studies have examined the factors that influence individuals’ willingness to talk directly to their family about this topic or the impact of these discussions. This investigation provides a partial test of a newly developed theory of information management to better understand the processes of family discussions about organ donation. Results from two studies generally support the utility of the theory in this context, suggest ways in which organ donation campaigns may improve their effectiveness, and recommend future directions for researchers in this area. Moreover, the data show differences across ethnic groups that support and extend past work in this area.     

基于RBF网络的粗糙集属性约简策略

粗糙集理论被广泛应用于人工智能、模式识别、数据挖掘和知识发现等领域。而对象的属性约简是是粗糙集理论中的重要问题之一。由于属性约简计算量较大,影响了的粗糙集的实际应用。本文用RBF神经网络高效和OLS对称性的特点,研究粗糙集属性的约简,解决了属性约简的难题,完成了算法的实现,取得了较好的效果。     

“双减”政策下我国中小学课后延时体育服务的演进历程、 机遇挑战及实现路径

“双减”政策是对宏观社会经济进行的调控，课后服务作为重要的社会工程，对促进社会进步、教育公平、青少年健康成长、核心素养的形成等具有重要的指导意义。运用文献资料法、历史研究法、逻辑分析等方法，对“双减”政策下课后延时体育服务的演进历程、机遇挑战及实现路径进行了分析。研究发现,课后延时体育服务的机遇为：国家政策支持体育类培训开展，为课后延时体育服务提供保障；重塑健康成长教育生态，为课后延时体育服务创造机遇；严禁学科类补课行为，为课后延时体育服务提供支持；学生体质发展切实需求，为课后延时体育服务创造条件。课后延时体育服务的挑战为：校内资源不足制约了课后延时体育服务的普及性；绩效保障不足影响了学校落实课后服务的积极性；管理体系不健全阻碍了社会力量的参与性；校外培训资本化混淆了教育结果的公平性。课后延时体育服务实现路径为：提升课后延时体育服务质量，丰富课后体育服务育人新理念；构建课后延时体育服务体系，明确各级管理职能新举措；引进社会力量参与，促进多元主体协同共育新格局；明确学校育人主体地位，践行五育并举的新航向。