实验应变采集处理系统的开发

介绍了一种新型用于常规力学性能实验的应变采集处理系统的设计开发。运用标准化数据采集卡结合Visual C 6.0编译器,开发了一套多用途实验应变智能采集处理系统。经过近5年的实验检验,系统运行稳定可靠,满足了力学性能试验的需要。     

First genome sequence of Chilean Brucella canis SCL strain provides insights on the epidemiology and virulence factors,explaining differences between geographical origins

BackgroundBrucella canis is the etiological agent of canine brucellosis, a worldwide neglected zoonosis that constitutes one of the major infectious causes of infertility and reproductive failure in dogs. Although genomic information available for this pathogen has increased in recent years, here we report the first genome sequencing of a B. canis strain in Chile, and the differences in virulence genes with other B. canis strains.ResultsGenome assembly produced a total length of 3,289,216 bp, N50 of 95,163 and GC% of 57.27, organized in 54 contigs in chromosome I, and 21 contigs in chromosome II. The genome annotation identified a total of 1981 CDS, 3 rRNA and 36 tRNA in chromosome I, and 1113 CDS and 10 tRNA in chromosome II. There is little variation between the different strains and the SCL isolate. Phylogenetic analysis showed that the Chilean SCL strain is closely related to B. canis and B. suis strains. Small differences were found when compared to the Serbian isolate, but all strains shared the same recent common ancestor. Finally, changes in the sequence of some virulence factors showed that the SCL strain is similar to other South American B. canis strains.ConclusionsThis work sequenced and characterized the complete genome of B. canis strain SCL, evidencing the complete presence of all the genes of the virB operon, and minor changes in outer membrane proteins and in the urease operon. Our data suggest that B. canis was introduced from North America and then spread throughout the South American continent.How to cite: Borie C, Bravo C, Dettleff P, et al. First genome sequence of Chilean Brucella canis SCL strain provides insights on the epidemiology and virulence factors, explaining differences between geographical origins Electron J Biotechnol 2021;49. https://dx.doi.org/10.1016/j.ejbt.2020.10.002.     

学生背部慢性劳损影响到身心健康的诊断与治疗

在体育保健教学中,笔者遇到一些由于背部创伤,形成慢性劳损,进而影响身体健康的学生。通过检查、诊断,采用了电针、按摩结合体育锻炼以及心理疗法,使这部分学生的症状得到了缓解。     

箍筋约束高强混凝土柱应力应变曲线的非线性有限元分析

利用ANSYS模拟四根不同配箍率的高强混凝土轴压柱,分析了各柱的裂缝图和应力应变曲线。结果表明,随着配箍率的增加,柱的延性和承载力可以得到提高;较好的验证了文献中的箍筋作用机理。     

外加应力对外延Pb（Zr1-xTix）O3薄膜相图及物理性质的影响

用非线性热力学方法,研究了外加应力及组分对外延单畴Pb（Zr1-xTix）O3（PZT）薄膜的相图及物理性质的影响。通过数值计算,得到了PZT薄膜在不同组分下的“外加应力-失配应变”相图。由相图可知,外加应力可以使薄膜发生铁电相变。在室温下,外加压应力能使薄膜的铁电相转变到顺电相。薄膜的压电系数对相变非常的敏感,施加一个适当的外加应力,可以大幅度提高压电系数。本文的计算结果,可以解释压痕仪和扫描力电镜研究铁电薄膜时所观察到的实验现象。     

韦耳与规范场理论

介绍了韦耳在规范场理论的建立、发展与完善过程中所作出的重要贡献及规范场中不可积相位因子与定域规范变换理论的建立过程,并简要介绍了规范场作用的两种不同描述方法。     

轿车下档板零件冲压失效分析

采用网格应变分析的方法,对武钢产DX56D＋Z钢材制作的流行车型下挡板零件开裂现象进行了分析。在冲压现场针对易开裂区进行网格试验,根据材料的变形行为,探讨了零件冲压开裂的原因,提出了降低开裂率的方法。     

电阻应变计法测量组合变形轴的扭矩和弯矩

分析用电阻应变计法测定组合变形轴的扭矩和弯矩时,如何布置应变片和组成测量电桥。所述思路,步骤和方法,可适用于其它组合变形构件。     

金属塑性变形过程的硬度预测

依据真实应力应变与工程应力应变的关系,建立了基于真实应力应变的硬度预测模型。进入塑性变形阶段后,将真实应力看作是材料在相应变形程度下的屈服点,并由此获得塑性变形的真实应变∈与相对真实屈服应变∈sp的关系,用于塑性变形阶段的硬度值计算。以45钢塑性变形为例,计算不同应变下的布氏硬度。结果表明,此模型预测的硬度值与试验结果较为吻合,可以较好地预测45钢在塑性变形过程中的各个硬度值。     

大蒜富硒研究进展

硒是人体必需的微量元素,具有抗氧化等多种重要的生物学功能．大蒜作为一种常见的蔬菜,具备较强的硒富集能力．通常可采用土壤施硒,叶面施硒和硒肥浸种三种方式提高大蒜的含硒量,而配合肥料施加的同时、恰当的施硒时机和操作方法也必不可少．并从加强其它蒜原富硒产品研究、提高富硒大蒜综合品质的方法及从种质角度出发如何提升大蒜富硒能力等方面提出了自己的看法．