浅谈德英语音比较

本文介绍了德语和英语语音的一般规则,以及这两种语言的字母名称和它们在单词中的发音,围绕德英语音比较,介绍了德语的语音特点.此文为学过“一外”英语者,再学习“二外”德语时,提供了一些比较的学习方法.     

合成二烃基二硫化物的新工艺及反应机理

二烃基二硫是一类重要香料。采用硫酸与 ＮＣＳ（Ｎ－氯代琥珀酰亚胺）反应．得到１７种二烃基二硫。其中５种未见文献报道。经红外，核磁和元素分析，证明其成分和结构与预定的一致。通过反应中间体的捕捉， ＮＣＳ与 ＮＢＳ（Ｎ－溴代琥珀酰亚胺）对比实验及 ＮＣＳ最佳用量和反应时间对产率影响的研究，提出该反应为氧化还原机理。文中还对不同结构硫醇的反应性作了研究。     

多尺度积角点检测和视觉颜色特征的鲁棒车牌定位算法

车牌图像包含的尺度、仿射变化及其复杂的背景是影响车牌定位准确度的重要因素。在高斯差（DOG）尺度空间框架下,笔者提出了一种基于多尺度乘积的角点特征和视觉颜色特征提取及其相融合的车牌定位算法。基于高斯差尺度空间的图像边缘信息,应用多尺度乘积分别提取具有尺度和仿射不变特性的角点和颜色特征,并在两特征融合结果基础上确定车牌位置候选区域;最后通过车牌区域特征点之间的距离及密集关系实现车牌的准确定位。对大量实拍的复杂环境下的车辆图像进行测试表明,该算法对车牌定位具有快速、高效的定位效果,且在噪声、仿射变换等方面的鲁棒性表现较好。     

基于共同属性和标签共现的标签消歧算法

为了提高基于标签的个性化推荐技术的准确率,提出了一种基于共同属性和标签共现的标签消歧模型,对已有的基于聚类的标签消歧算法进行改进,针对不同的标签语义问题分别采用不同的方法,缓解了原算法不能识别不同语义的问题。对于多义词语义问题,使用同义词模型进行消歧;对于近义词、同义词语义问题,使用近、同义词模型进行消歧,并将该模型应用于个性化推荐算法。利用公共数据集MovieLens Latest Datasets进行了个性化推荐实验。实验表明,当用户推荐项目数量递增时,推荐算法的准确率和召回率都有提高,能有效消除标签中存在的歧义。     

从软件业的历史看我国计算机教育的发展

试图通过对全球软件业发展历史的回顾,探讨其发展过程中的几个不同时期的特点,并进而结合对未来软件业发展方向的估计,提出我国计算机教育今后应该注意的几个问题.     

Optimization of antioxidant activity by response surface methodology in hydrolysates of jellyfish (Rhopilema esculentum) umbrella collagen

To optimize the hydrolysis conditions to prepare hydrolysates of jellyfish umbrella collagen with the highest hydroxyl radical scavenging activity, collagen extracted from jellyfish umbrella was hydrolyzed with trypsin, and response surface methodology (RSM) was applied. The optimum conditions obtained from experiments were pH 7.75, temperature (T) 48.77 °C, and enzyme-to-substrate ratio ([E]/[S]) 3.50%. The analysis of variance in RSM showed that pH and [E]/[S] were important factors that significantly affected the process (P<0.05 and P<0.01, respectively). The hydrolysates of jellyfish umbrella collagen were fractionated by high performance liquid chromatography (HPLC), and three fractions (HF-1>3000 Da, 1000 Da<HF-2<3000 Da, and HF-3<1000 Da) were collected. The HF-2 fraction had the highest hydroxyl radical scavenging activity with the highest yield compared with the other two fractions. Furthermore, HF-2 also showed the strongest Cu²⁺-chelating ability and the best tyrosinase-inhibitory activity.     

Synergistic actions of complement and lysozyme in clearance of Escherichia coli from amphioxus Branchiostoma belcheri

Amphioxus appears lacking free circulating blood cells. How it clears invading pathogens from its body remains unknown to date. We demonstrate here that amphioxus Branchiostoma belcheri is capable of efficiently eliminating the invading bacterium Escherichia coli from its humoral fluid, and the complement and lysozyme are both involved in the elimination of the invading pathogen. Both the complement and lysozyme act in concert against the invading bacterium, but the complement appears playing a more dominant role than the lysozyme.     

2,2′,4,4′-四溴联苯醚的环境毒理学研究进展

2,2′,4,4′-四溴联苯醚(tetra-brominated diphenyl ethers,BDE-47)是环境样品及生物组织中含量最高的PBDEs同系物之一,具有多方面的健康危害作用.本文简要介绍BDE-47的理化性质、主要暴露途径及人体组织含量水平,并对其内分泌干扰毒性、神经毒性、肝脏毒性、生殖毒性及免疫毒性等作了归纳与总结.结果表明,对BDE-47环境毒理学的研究缺乏系统性和深入性.为此,一方面可从其各种毒性作用之间的关联入手,另一方面可引入医学与生命科学的新技术与研究策略,全面深入地研究其生物毒性机制.     

浅谈自动喷水灭火系统

自动喷水灭火系统同时具备了防火、控火、灭火的功能，是国际上公认的最为有效的自动灭火设施，是现代建筑防火技术的重要组成部分。文章简单对自动喷水灭火系统进行分析，对设计中常见问题进行讨论。     

Recent research progress in computational solid mechanics

Computational mechanics has had a profound impact on science and technology over the past five decades.It has numerically transformed much of the classical theory models into practical tools for predicting and understanding the complex engineering and science system.A short review is given in this paper on some recent progress in computational solid mechanics at multi-scales.