基于多尺度数学形态学和高低频能量比值的海上风电场内部瞬态过电压特征分析

目前,海上风电场集电系统因电气设备频繁操作或故障所引起的高频瞬态过电压尤为严重。为识别不同类型下海上风电场内部过电压的瞬态特性,该文首先提出一种多尺度数学形态学信号特征提取方法,构建形态学结构元素新算子,运用多尺度数学形态分解方法提取瞬态过电压的高低频成分,构建适用于识别海上风电场内部瞬态过电压类型的时域特征量。再基于所构造的高频特征量和高低频能量比值识别特征量,结合支持向量机分类器模型对典型的内部瞬态过电压分类识别。仿真和试验研究表明,所提出的数学形态学算法相对于传统的小波算法,构造的特征量区分度更明显,可以准确地识别过电压类型,为海上风电场变电站电气设备的电压保护整定和绝缘配合奠定基础。     

基于机器学习方法的入侵检测技术的研究

入侵检测技术是近20年来才出现的一种有效保护网络系统免受网络攻击的新型网络安全技术.随着网络技术的迅速发展、安全问题的日益突出,传统的入侵检测系统已难以满足对越来越复杂的网络攻击的检测任务,将机器学习的技术引入到入侵监测系统之中以有效地提高系统性能,已成为入侵检测技术的研究热点.本文主要介绍了入侵检测系统的基本结构以及几种机器学习方法在入侵检测中的应用,其中包括:基于贝叶斯分类的方法、基于神经网络的方法、基于数据挖掘的方法与基于支持向量机的方法.     

地方师范院校物联网工程专业学生创新能力培养研究

地方师范院校工科专业普遍存在师资薄弱,资源投入不足的问题,导致工科专业学生的动手实践与创新能力不足,无法达到“新工科”专业建设的培养目标。针对此问题,结合内江师范院物联网工程专业在办学过程中遇到的问题,分别从优化师资配置、校企合作共建课程、采用项目学习法教学、建立以解决问题为核心的评价标准等几方面进行改革。通过方案实施,学生的动手实践能力与创新能力得到了明显提升。     

校际共享实验教学中心建设初探——以内江市高校为例

高校普遍存在实验室资源配置重复、使用率低、专业实训教师短缺等问题。文章借鉴欧洲“流动制”教学方式与经验,提出建立校际共享实验教学中心。该中心充分发挥各校的优势实验教学平台和资源,建立共享机制与互认机制,配备专业实训教师,如此便能让学生能够充分享用优秀教育资源,以大力提升大学毕业生社会竞争力和高校办学实力。     

土质固化用高分子粘结剂的研制及性能研究

公路路基多年来一直沿用的方式是二灰碎石和水泥稳定砂粒，本文报道了一种直接征用原土并用高分子粘结剂将土固化后，直接作为公路路基使用的方法。采用正交设计对粘合剂的主料及部分配合剂对性能的影响进行了系统的研究，从中求得了最佳的工艺条件，并通过实验对其进行了验证。     

Genomics of industrial Aspergilli and comparison with toxigenic relatives

Aspergillus oryzae has been used in Japanese fermentation industries for more than a thousand years. The species produces large amounts of various hydrolytic enzymes and has been successfully applied to modern biotechnology. The size of the A. oryzae genome (37.5 Mb) is very close to that of A. flavus and A. niger, and 20-30% larger than that of either A. nidulans or A. fumigatus. A. oryzae and A. flavus have exactly the same number of aspartic proteinase genes, of which each orthologous pair shares highly conserved amino acid sequences. Synteny analysis with A. fumigatus and A. nidulans showed that the A. oryzae genome has a mosaic structure consisting of syntenic and non-syntenic blocks. In the microorganisms to be compared, the density of the genes having homologs was obviously higher on the syntenic than on the non-syntenic blocks. Expression analysis by the DNA microarray supported the significantly lower expression of genes on the non-syntenic than on the syntenic blocks.     

Surficial stability analysis of soil slope under seepage based on a novel failure mode

Normally, the edge effects of surficial landslides are not considered in the infinite slope method for surficial stability analysis of soil slopes. In this study, the limit stress state and discrimination equation of an infinite slope under saturated seepage flow were analyzed based on the Mohr-Coulomb strength criterion. Therefore, a novel failure mode involving three sliding zones (upper tension zone, middle shear sliding zone, and lower compression zone) was proposed. Accordingly, based on the limit equilibrium analysis, a semi-analytical framework considering the edge effect for the surficial stability of a soil slope under downslope seepage was established. Subsequently, the new failure mode was verified via a numerical finite element analysis based on the reduced strength theory with ABAQUS and some simplified methods using SLIDE software. The results obtained by the new failure mode agree well with those obtained by the numerical analysis and traditional simplified methods, and can be efficiently used to assess the surficial stability of soil slopes under rainwater seepage. Finally, an evaluation of the infinite slope method was performed using the semi-analytical method proposed in this study. The results show that the infinite slope tends to be conservative because the edge effect is neglected, particularly when the ratio of surficial slope length to depth is relatively small.     

喷涂聚脲弹性体耐水性能的研究

以不同种类多元醇与二苯基甲烷二异氰酸酯（MDI）和液化MDI合成预聚物作为A组分,端胺基聚醚、胺类扩链剂为R组份,制成喷涂聚脲弹性体。讨论了多元醇种类及其相对分子质量、A组分的NCO含量、扩链剂等对喷涂聚脲弹性体耐水性能的影响。结果表明,由二聚体聚酯二醇制得的喷涂聚脲弹性体耐水性能最好,其次是聚四氢呋喃多元醇,聚氧化丙烯醚二醇的耐水性最差;随着多元醇相对分子质量的增加,聚氧化丙烯醚二醇和聚四氢呋喃醚二醇的耐水性提高,而二聚体聚酯二醇的耐水性能变化不大;A组分的NCO含量增加,耐水性提高;不同扩链剂的耐水性有很大差异,依次为3,3’．二氯4,4’-二苯基甲烷二胺〉二乙基甲苯二胺〉3,5-二甲硫基甲苯二胺〉4,4’-双仲丁胺基二苯基甲烷。     

金属钛的制备研究

介绍了金属钛的制备途径,详细阐述了金属热还原法和熔盐法中几种具有代表性的钛金属制备方法。通过对比分析Kroll法、氟盐法、FFC法、OS法及EMR/MSE法的机理、优缺点和可行性,指出TiO2熔盐电解法和氟盐法有望取代Kroll法,成为金属钛制备的发展方向。