模糊控制器在窑炉温度控制系统中的应用及计算机仿真

对陶瓷工业窑炉中的温度模糊控制问题进行了探讨,提出了模糊控制器在窑炉温控上的具体应用方法,并进行了计算机仿真,仿真结果表明模糊控制效果良好,具有较好的应用前景。     

不同分子量聚酯的羟值分析方法

用醋酐／高氯酸／乙酸乙酯法，醋酐吡啶回流法，分别对相对分子质量为１１００－１２０００的聚酯进行了羟值的测定，并用气压渗透法和析出物溶解重滴法进行了核对。结果表明醋酐／高氯酸／乙酸乙酯法对于Ｍ〈５０００的聚酯是适用的，而高分子量的聚酯则必须用醋酐／吡啶回流法，才能获得满意的结果。     

石油亚砜树脂分离稀土的性能研究

应用石油亚砜萃取树脂与ＮＨ＿４ＣＮＳ体系，测定了稀土元素的分配比（Ｋｄ）、分离因素（β）和分离度Ｒｓ），讨论了ＮＨ＿４ＣＮＳ的浓度、稀土进样量和温度等对稀土分离的影响。应用于混合稀土的分离和测定，分析了６０．３２％的氧化钇，相对标准偏差为±１．４７％。     

Oxygen evolution and hypochlorite production on Ru-Pt binary oxides

The electrocatalytic activities of Ru-Pt binary oxide electrodes prepared by thermal decomposition for both oxygen and chlorine evolution reactions (OER and CER) were investigated by cyclic voltammetry (CV) and log i/E relationships (Tafel study). Both CV and Tafel studies revealed that the electrodes from the coating solutions with 60 and 20 mol % Pt content possessed the maximum apparent activity for OER and optimal apparent activity for CER/hypochlorite production, respectively. The specific activity (i/q ^*) revealed that mixing of the RuO₂ and PtO _x had no synergistic effects for OER due to the occurrence of phase segregation, which was revealed by element mapping/surface morphologies and Auger electron spectroscopy. Lower current efficiencies for hypochlorite production were found on the freshly prepared binary electrodes (type I electrodes) than on those having been treated by repetitive CVs (type II electrodes). Stability testing of both type I and II electrodes was measured in 0.5 m NaCl solution at 300 mA cm^–2 for 480 h, indicating that both type I and II electrodes are quite stable under the above conditions.     

下喷自吸环流反应器中气-液局部相际传质模型

引言 下喷自吸环流反应器是在结合喷射、环流、自吸等优点基础上而开发出的一种新型高效反应器,开展该反应器内局部气液传质模型的研究,对于该反应器的优化设计及放大具有极重要的理论意义.多年来,经典传质理论的不足与局限都在经历不断的修正与改进.其中,激光多普勒测试在传质研究中的应用使得人们对湍流在传质中的重要性有了     

Edwards曲线快速标量乘算法研究

标量乘法是椭圆曲线密码算法中最核心的运算,其运算速度影响着整个密码体制的实现效率。首先,详细地介绍了Edwards曲线的基本概念。其次,为了提高标量乘法的运算速度,针对椭圆曲线标量乘算法进行了研究,引入了一种可以用来计算连续倍点2◢△mP◣的算法CDA。为了提高CDA的计算效率,提出了将标量◢k◣表示为4-NNAF形式以减少◢k◣的长度,再结合CDA计算标量乘法可以有效地减少运算量。最后根据算法的运算量分析和具体例子得出,减少标量◢k◣长度后的计算效率提高了13%以上。为了进一步加快运算速度,又提出了对CDA中乘法运算和模逆运算采用并行结构来减少标量乘法的运算次数。计算结果表明,并行后的计算效率提高了36%以上。     

高校教师的隐性流失

本文分析了当前高校教师的隐性流失的严重性及流失形式的多样性,认为这种现象严重浪费了教育资源,影响了教学质量,毒化了校园环境和社会环境,必须采取坚决措施才能取得成效,制止流失.     

丙交酯的合成

以DL－乳酸为原料在催化剂存在下，加热、减压脱水合成了DL－丙交酯，研究了温度、压力、反应时间等反应条件对丙交酯产率的影响，用IR等分析测试仪器对丙交酯进行了表征。     

Allelopathic Potential and Chemical Constituents of Volatile Oil from Ageratum conyzoides

Fresh leaves and volatile oil of the important weed Ageratum conyzoides in south China were highly inhibitory to seedling growth of various cultivated crops, especially in an adverse habitat. The constituents of the volatile oil were analyzed by GC-MS. Eleven components were identified and six main components, precocene I, precocene II, 3,3-dimethyl-5-tert-butylindone, -caryophyllene, -bisabolene, and fenchyl acetate, were isolated by means of column chromatography. Precocene I, precocene II, -caryophyllene, and 3,3-dimethyl-5-tert-butylindone inhibited seedling growth of acceptor plants. Inhibitory activity of the volatile oil was more intense than that of the pure components. Fenchyl acetate and -bisabolene have no inhibitory activity, but when mixed with precocene II, they increased the inhibitory activity to growth of acceptor seedling plants. Experiments show that allelopathic synergism exists among allelochemicals of Ageratum conyzoides.     

一种结合主题模型的推荐算法

针对传统协同过滤推荐算法存在的冷启动、数据稀疏以及相似度度量的准确性问题,基于LDA主题模型对文本隐式主题挖掘的有效性和KL散度在主题分布相似性度量的准确性,提出了结合LDA主题模型的矩阵分解推荐算法。首先,利用改进的LDA算法输出项目-主题分布,并用困惑度作为主题数设置的修正函数;然后分别基于余弦相似度和KL散度计算得到项目相似度矩阵,将得到的相似度矩阵结合原评分训练集输出预评分,再将预评分填充到训练集;最后将训练集输入ALS矩阵分解算法得到推荐结果。通过MovieLens数据集的实验结果表明,该算法在不同隐式参数设定下均能得到比ALS推荐算法以及更小的预测误差,并且最优预测误差小于传统推荐算法。该实验说明了通过集成LDA主题模型的ALS算法效果要优于其他推荐算法。