超临界不锈钢材质铸件的涂料开发和应用

从超临界汽轮机用ZG1Cr10MoVNiN不锈钢铸件对于新型涂料的要求方面进行了阐述,主要介绍了一种适合于超临界汽轮机用不锈钢铸件涂料开发和利用,并且通过实际生产的对比试验,证明了这种新型涂料的作用和应用的可行性。     

月桂酰苯甲酰甲烷的合成及其对聚氯乙烯辅助热稳定性能的研究

以月桂酸甲酯和苯乙酮为原料,通过克莱森缩合反应,合成了一种具有β-二酮结构的月桂酰苯甲酰甲烷,用红外光谱、核磁共振波谱对产物结构进行了表征。考察了反应条件对产物收率的影响,最佳的合成工艺条件为:二甲苯为溶剂,新鲜甲醇钠为催化剂,n(月桂酸甲酯):n(苯乙酮)=1.2:1,回流温度下反应3 h,收率可达85%。研究了其作为聚氯乙烯辅助热稳定剂的热稳定性能,结果表明,所制备的月桂酰苯甲酰甲烷是一种优良的聚氯乙烯用无毒辅助热稳定剂。     

HDDR处理过程中Nd－Fe－B永磁合金的相变和富钕相的行为

本研究为Ｎｄ－Ｆｅ－Ｂ合金在ＨＤＤＲ处理过程中其相和显微组织的变化以及富钕相在变化中的扩散行为提供了确凿的证据和补充。对于高Ｎｄ含量的Ｎｄ－Ｆｅ－Ｂ合金,处理过程中Ｎｄ与Ｆｅ的相互扩散是ＨＤＤＲ法处理的Ｎｄ－Ｆｅ－Ｂ粉末成分变得均匀、磁性能得以改善的基本原因．     

CRISPR/Cas9 Technology and Its Utility for Crop Improvement

The rapid growth of the global population has resulted in a considerable increase in the demand for food crops. However, traditional crop breeding methods will not be able to satisfy the worldwide demand for food in the future. New gene-editing technologies, the most widely used of which is CRISPR/Cas9, may enable the rapid improvement of crop traits. Specifically, CRISPR/Cas9 genome-editing technology involves the use of a guide RNA and a Cas9 protein that can cleave the genome at specific loci. Due to its simplicity and efficiency, the CRISPR/Cas9 system has rapidly become the most widely used tool for editing animal and plant genomes. It is ideal for modifying the traits of many plants, including food crops, and for creating new germplasm materials. In this review, the development of the CRISPR/Cas9 system, the underlying mechanism, and examples of its use for editing genes in important crops are discussed. Furthermore, certain limitations of the CRISPR/Cas9 system and potential solutions are described. This article will provide researchers with important information regarding the use of CRISPR/Cas9 gene-editing technology for crop improvement, plant breeding, and gene functional analyses.     

Identification of miRNAs and Target Genes at Key Stages of Sexual Differentiation in Androdioecious Osmanthus fragrans

Androdioecy is the crucial transition state in the evolutionary direction of hermaphroditism to dioecy, however, the molecular mechanisms underlying the formation of this sex system remain unclear. While popular in China for its ornamental and cultural value, Osmanthus fragrans has an extremely rare androdioecy breeding system, meaning that there are both male and hermaphroditic plants in a population. To unravel the mechanisms underlying the formation of androdioecy, we performed small RNA sequencing studies on male and hermaphroditic O. fragrans. A total of 334 miRNAs were identified, of which 59 were differentially expressed. Functional categorization revealed that the target genes of differentially expressed miRNAs were mainly involved in the biological processes of reproductive development and the hormone signal transduction pathway. We speculated that the miRNA160, miRNA167, miRNA393 and miRNA396 families may influence the sex differentiation in O. fragrans. Overall, our study is the first exploration of miRNAs in the growth and development process of O. fragrans, and is also the first study of androdioecious plants from the miRNA sequencing perspective. The analysis of miRNAs and target genes that may be involved in the sex differentiation process lay a foundation for the ultimate discovery of the androdioecious molecular mechanism in O. fragrans.     

轮廓测量系统中摄像机的光学畸变校正方法

在基于机器视觉的轮廓测量系统中,由于摄像机的透镜透光率不均,成像中存在光学畸变,对测量精度造成影响。为了对光学畸变进行校正,论文首先建立畸变数学模型,然后使用系统测量正方形标定板得到存在畸变的轮廓数据,根据存在畸变的轮廓数据的几何特征和直线约束条件使用LM优化算法完成对畸变模型中参数的标定。通过实验多次标定同一套轮廓测量系统,将标定结果与已有方法进行比较。实验结果表明,相较于已有算法,该论文所提方法多次标定的结果标准差更小,说明该论文所提方法具有更好的鲁棒性。     

钢结构用钢材新标准及其应用

简要介绍《碳素结构钢》（GB/T700-2006）、《建筑结构用钢板》（GB/T19879-2005）、《热轧H型钢和剖分T型钢》（GB/T11263-2005）与《建筑结构用冷弯矩形钢管》（JG/T178-2005）等10项新编或新修订钢铁产品标准的内容与技术要求,并对在工程设计中,如何合理地应用这些标准和选材提出建议。     

高速铁路客车轴承滚子凸度量的有限元分析

用有限元方法对高速铁路客车用圆柱滚子轴承的修型滚子的凸度量进行了研究,分析了凸度量对接触应力和等效应力的影响,并确定了最佳凸度量。     

氧化铝回转窑烧成带火焰图像识别系统

针对氧化铝回转窑烧成带工况变化复杂,与产品质量指标密切相关的关键过程变量无法实现在线连续检测的难题,模拟传统的人工看火操作过程,提出利用图像处理与模式分类技术对与回转窑工业过程自动控制密切相关的烧成带状态进行自动识别的方法。组建了系统的硬件、软件平台,设计并开发了基于混合数据特征识别的氧化铝回转窑烧成带工况识别软件。该系统成功应用于国内某氧化铝厂,为回转窑的优化控制提供了重要的辅助决策信息。