苦咸水反渗透淡化中膜面结垢预测及防垢进展

苦咸水反渗透（BWRO）中的防垢过程,首先取决于给水水质,而根据水质条件和垢在膜面的形成机理采取相应的防垢措施是非常重要的。 显然,有效地管控膜面无机结垢及抑制膜面污染需要开展无机结垢趋势的预测、防垢措施和非破坏性无机垢监控等方面的技术研究。 一系列传统和新兴的分析技术,包括摩尔比率法、直接目测法和光谱法等已应用于BWRO过程中膜面防垢研究。 本文详细综述了该过程中无机结垢趋势的预测、防垢方法和非破坏性无机垢监控技术等方面的研究进展。 此外,针对目前的研究方向提出了建议。     

Analyzing the causation of a railway accident based on a complex network

In this paper, a new model is constructed for the causation analysis of railway accident based on the complex network theory. In the model, the nodes are defined as various manifest or latent accident causal factors. By employing the complex network theory, especially its statistical indicators, the railway accident as well as its key causations can be analyzed from the overall perspective. As a case, the ＂7.23＂ China-Yongwen railway accident is illustrated based on this model. The results show that the inspection of signals and the checking of line conditions before trains run played an important role in this railway accident. In conclusion, the constructed model gives a theoretical clue for railway accident prediction and, hence, greatly reduces the occurrence of railway accidents.     

Quantitative Analysis of Catalpol in Chinese Patent Medicine Lixin Pill by Near-infrared Diffuse Reflectance Spectroscopy

Lixin pill is a typical Chinese patent medicine with anti-rheumatic heart disease activity that has been widely used in clinical practice. Therefore it is very important to detect the concentration of catalpol, as the main component of the active ingredient. Near-infrared reflectance（NIR） spectroscopy was used to study the content of catalpol in the unprocessed Chinese patent medicine of Lixin pills. NIR is applied to quantitatively analyze 77 sam- ples, which were randomly divided into a calibration set containing 61 samples and a prediction set containing 16 samples. To get a satisfying result, partial least squares（PLS） regression was utilized to establish quantitative models. In PLS regression, the values of coefficient of determination（R2） and root mean square error of cross-validation （RMSECV） of PLS regression are 0.9419 and 0.0216, respectively. The process of establishing model, parameters of model, and prediction results were also discussed in detail（root mean square error of prediction is 0.0164）. The over- all results show that NIR spectroscopy can be efficiently utilized for the rapid and accurate analysis of routine chemical compositions in the Chinese patent medicine of Lixin pills. The prediction set suggests that this quantitative analysis model has excellent generalization ability and prediction precision. Accordingly, the result can provide tech- nical support for the further analysis of catalpol in unprocessed Lixin pill. Moreover, this study supplied technical support for the further analysis of other Chinese patent medicine samples.     

改进型GMDH网络在便携式X射线荧光分析仪中的应用

在能量色散X荧光分析技术中,常用基本参数法、 经验系数法、 人工神经网络等方法建立计数率和元素含量之间的物理模型,此外,GMDH(group method of data handing)作为一种新型的处理复杂非线性问题的方法,被大量理论和实验证明优于大部分的计算统计方法。GMDH是一种自组织学习的前馈型网络,自动筛选并在训练过程中确定其结构,对GMDH进行改进并对结果进行定量预测,参考值与预测值的相对误差在5%以内,方法简洁、 合理、 可靠。     

基于MFGM企业项目链风险元传递研究

为了对企业项目间风险元传递预测进行研究,本文首先提出项目链风险元传递概念及企业项目链风险传递四面体模型,然后以企业项目链风险传递链式结构为切入点,引入灰色预测、傅里叶级数和马尔科夫链理论,构建了马尔科夫—傅里叶级数修正灰色预测模型(MFGM),用来预测项目链式结构的风险元传递,最后以项目工期为风险元,算例分析基于该模型的项目链风险元传递的预测情况,结果表明该模型具有可行性和有效性。     

基于学生预测与实验验证的理解教学——“氯气与水反应”教学反思

针对教学中课前“导学案”的呈现形式,以及在预习基础上学生对课本知识早已认知,课堂教学中一些活动常流于形式,学生在学习中主体性差,未实现对知识的真正理解的困惑,在“氯气与水反应”教学的重难点突破中,笔者采用课前让学生设计实验方案,预测现象,课堂实验验证,理解氯水复杂性,教学中深感理解活动中学生主体性的自主迸发,情感上的豁然开朗。     

基于野外Vis-NIR光谱的土壤有机质预测与制图

利用野外实时快速获取的土壤光谱进行土壤有机质(SOM)预测与制图是精确农业与土壤遥感制图的必然需要,利用ASD FieldSpec Pro FR野外型光谱仪实时快速获取的光谱数据,去除噪声较大的边缘波段后,进行倒数的对数转换(Log(1/R))为吸收光谱。在分析吸收光谱和光谱指数与SOM关系的基础上,采用偏最小二乘回归法进行SOM的建模预测并借助地统计学方法进行SOM空间变异制图研究。结果表明,建模效果好的指标分别为特征波段(R2=0.91,RPD=3.28),归一化光谱指数(R2=0.90,RPD=3.08),特征波段与3个光谱指数组合(R2=0.87,RPD=2.67),全波段(R2=0.95,RPD=4.36)。光谱指标的克里格制图与实测SOM制图表现出相同的空间变异趋势,不同的指标均达到了较好的预测效果。     

Applications of parabolized stability equation for predicting transition position in boundary layers

The phenomenon of laminar-turbulent transition exists universally in nature and various engineering practice.The prediction of transition position is one of crucial theories and practical problems in fluid mechanics due to the different characteristics of laminar flow and turbulent flow.Two types of disturbances are imposed at the entrance,i.e.,identical amplitude and wavepacket disturbances,along the spanwise direction in the incompressible boundary layers.The disturbances of identical amplitude are consisted of one two-dimensional(2D) wave and two three-dimensional(3D) waves.The parabolized stability equation(PSE) is used to research the evolution of disturbances and to predict the transition position.The results are compared with those obtained by the numerical simulation.The results show that the PSE method can investigate the evolution of disturbances and predict the transition position.At the same time,the calculation speed is much faster than that of the numerical simulation.     

先进高强度钢的断裂失效准则研究

先进高强度钢(AHSS)是通过相变获得高强度的应用前景最好的汽车轻量化材料。与传统深拉钢相比,AHSS韧性相对较低,在冲压成形过程中容易发生断裂,阻碍了它在汽车上的广泛应用,因而AHSS的断裂失效研究成为当前国内外研究的热点。本文以AHSS的代表钢种双相钢(DP)为研究对象,通过试验与数值计算相结合的方法研究其在不同三轴应力状态下的失效特性,尝试寻找一个适用于它的失效准则,用于其断裂失效的预测。     

深部地下工程岩爆预测的筛选蚁群聚类算法

为了提高仿生聚类算法的计算效率,对传统的蚁群聚类算法进行改进,采用数据合并机制提出了 一种筛选蚁群聚类算法。采用筛选蚁群聚类算法,在岩爆工程实例资料分析的基础上,基于工程类比的思想 判断岩爆的发生状态,提出了一种深部地下工程岩爆预测的新方法。通过多个煤矿深部地下工程岩爆实例的 应用研究证明,和传统的蚁群聚类算法相比,在不显著增加计算难度和复杂度的情况下,新算法对工程实例的 判断准确率更高,其准确率达92%,计算效果更好;而且,计算速度有较大幅度的提高,其计算时间缩短近 40%,说明新算法的计算效率更高。因此,筛选蚁群聚类算法是一种比较实用的岩爆预测新方法,值得在深部 地下工程岩爆研究领域推广应用。