结构和内容联合提取的XML网页分类研究

针对XML网页特点,重点研究了XML文档结构和内容特征的提取方法,提出了一种基于频繁结构层次空间模型的联合特征提取策略,并给出了结构特征权重和关键词出现的位置及频度权重的计算公式,并根据计算结果提取XML网页特征矩阵,分别就结构、内容联合提取三种情况进行分类测试,通过ROSSETA系统,利用粗糙集优越的属性约简构造文本分类系统,实现XML文档分类。实验表明,该方法分类准确度较高,计算量较小。     

商陆浆果黄酮类化合物和多糖的提取与测定研究

以商陆浆果为原料,用石油醚去脂-乙醇抽提-甲醇溶解的方法提取了商陆浆果中黄酮类化合物．采用石油醚去脂-热水提取-三氯乙酸法除蛋白-活性炭脱色-乙醇醇析提取、沉淀的提取工艺从商陆浆果中提取多糖,并用苯酚-硫酸比色测定法对其进行定量测定．结果表明：商陆浆果中粗多糖含量为3．77％．用HCl-镁粉、HCl-锌粉热水浴、2％AlCl3-乙醇、1％NaOH溶液和1％FeCl3-乙醇与95％乙醇提取物进行显色反应,呈现黄酮类化合物性质特征颜色;利用紫外分光光度法测定甲醇提取物的紫外吸收光谱,观察到黄酮类化合物的特征吸收峰带,表明样品提取物中含有黄酮类化合物．     

聚乙二醇-硫酸铵双水相体系萃取分离食用色素的研究

研究了硫酸铵-聚乙二醇（PEG）双水相体系中,PEG浓度、（NH4）2SO4用量、Trition X-100用量、溶液酸度等因素对常见食用色素叶绿素铜钠盐（SCC）萃取率的影响。研究表明,在50mL的总体积中,聚乙二醇的浓度为30％,10％的SCC溶液的体积为1mL,（NH4）2SO4用量为10．0g,表面活性剂Trition X-100的用量为1．0mL,在中性或微碱性条件下,叶绿素铜钠盐的萃取率达97．98％。叶绿素铜钠盐最大吸收峰位于632nm,实验测定其溶液体积在0—1．2mL范围内符合比耳定律,标准工作曲线为Y=1．0117x＋0．0055,R=0．9999。在实验条件下,金属离子Zn^2＋、Mn^2＋、Mg^2＋、Fe^2＋、Ni^2＋、Cu^2＋对SCC的萃取均不干扰。     

子波变换在超宽带雷达中的应用

介绍了连续子波变换的定义和性质：基于子波变换在时域和频域的良好局部化性质;研究其在宽带信号的相关处理和超宽带雷达目标特征提取两个方面的应用,理论分析和试验结果表明,在超宽带雷达信号处理中,宽带相关处理相当于时间尺度域的匹配滤波,采用连续子波变换从频域采样数据中提取目标散射中心是一种较为鲁棒的方法。     

新显色剂MDMC萃取光度法测定Fe（Ⅲ）的研究和应用

文章研究了吗啉荒酸吗啉与Ｆｅ（Ⅲ）显色反应的条件,确定在ｐＨ＝４．０～６．０形成棕色配合 物,可见光区最大吸收波长λｍａｘ＝４００ｎｍ,表观摩尔吸光系数ε＝ ９． ４２ ×１０３Ｌ·ｍｏｌ－１·ｃｍ－１,应用拟定 方法测定合成水样中Ｆｅ（Ⅲ）含量,结果满意．     

中日史前拔牙年龄和次数比较研究

探讨史前拔牙个体的年龄和次数,对了解史前社会生活和社会意识、宗教信仰具有重要意义。认为中国和日本新石器时代的原生拔牙应该是青春期或成年期拔牙。中国新石器时代只存在一次拔牙现象,而日本新石器时代存在多次拔牙现象。这说明虽然同处新石器时代,但社会结构和社会意识有所不同。     

Trend estimation of multivariate time series with controlled smoothness

This paper extends the univariate time series smoothing approach provided by penalized least squares to a multivariate setting, thus allowing for joint estimation of several time series trends. The theoretical results are valid for the general multivariate case, but particular emphasis is placed on the bivariate situation from an applied point of view. The proposal is based on a vector signal-plus-noise representation of the observed data that requires the first two sample moments and specifying only one smoothing constant. A measure of the amount of smoothness of an estimated trend is introduced so that an analyst can set in advance a desired percentage of smoothness to be achieved by the trend estimate. The required smoothing constant is determined by the chosen percentage of smoothness. Closed form expressions for the smoothed estimated vector and its variance-covariance matrix are derived from a straightforward application of generalized least squares, thus providing best linear unbiased estimates for the trends. A detailed algorithm applicable for estimating bivariate time series trends is also presented and justified. The theoretical results are supported by a simulation study and two real applications. One corresponds to Mexican and US macroeconomic data within the context of business cycle analysis, and the other one to environmental data pertaining to a monitored site in Scotland.     

沉淀法提取混合稀土的工艺条件试验

本文对草酸—碳铵混合物(H_2C_2O_4·2H_2O—NH_4HCO_3)作沉淀剂处理离子型稀土矿水的工艺条件作了系统的试验,找出了提取稀土的最佳工艺条件,很有希望降低提取成本和提高效益。     

超临界CO2萃取釜卡箍式快开结构强度分析及优化设计

为了实现萃取釜的轻量化设计,采用ANSYS软件对60 L超临界CO2萃取釜进行有限元分析,得出萃取釜卡箍 式快开结构的应力分布;在满足强度和抗疲劳性能的前提下,分别采用安全裕度法和JB 4732应力评定法提取状态变 量,以体积最小为目标进行优化设计。结果表明：2种方法优化后的效果明显,优化后的体积分别减少了22. 5%和 24. 2%。优化设计达到了轻量化目的,同时为萃取釜卡箍式快开结构优化设计提供有益参考。     

Decomposition of a state-space model with inputs

This article shows how to compute the in-sample effect of exogenous inputs on the endogenous variables in any linear model written in a state–space form. Estimating this component may be either interesting by itself, or a previous step before decomposing a time series into trend, cycle, seasonal and error components. The practical application and usefulness of this method is illustrated by estimating the effect of advertising on the monthly sales of Lydia Pinkham's vegetable compound.