Novel iterative learning controls for linear discrete-time systems based on a performance index over iterations

An optimal iterative learning control (ILC) is proposed to optimize an accumulative quadratic performance index in the iteration domain for the nominal dynamics of linear discrete-time systems. Properties of stability, convergence, robustness, and optimality are investigated and demonstrated. In the case that the system under consideration contains uncertain dynamics, the proposed ILC design can be applied to yield a guaranteed-cost ILC whose solution can be found using the linear matrix inequality (LMI) technique. Simulation examples are included to demonstrate feasibility and effectiveness of the proposed learning controls.     

基于人工神经网络与主成分分析的建筑工料(工日)估算方法

针对建筑工料(工日)估算问题,本文首先利用主成分分析得到一组新的输入变量,相对于原始输入变量,有效降低了输入维数,且消除了各输入分量之间的相关性。然后以新的输入变量作为改进型BP网络的输入进行训练与估算,得到了一种新工料(工日)估算方法。仿真结果表明与直接利用BP网络训练估算相比较,采用本文的方法,估算结果更加准确。     

基体对SnO_2 UPF成膜结构的影响

对不同基体上采用直流气体放电活化反应蒸发沉积法（ＤＣ－ＧＤＡＲＥ）制备的氧化锡超微粒薄膜的晶相结构进行了分析。结果表明：不同的基体对此类薄膜的生长有极重要的影响作用。     

改进YOLOv5网络的鱼眼图像目标检测算法

针对目标检测算法应用在鱼眼图像数据集上检测精准率低、算法实时性差等问题,提出了在化工场景下利用改进网络YOLOv5进行鱼眼图像中的目标检测算法。由于无公开化工场景鱼眼图像数据集,提出了利用不同类型图像间像素点的坐标关系,将数据集转换为同鱼眼图像具有相同畸变效果的图像。为消除鱼眼图像中有效区域外的冗余信息,将线扫描算法应用到YOLOv5s数据预处理阶段。为在缩减模型的同时保证算法的检测精准率,提出了采用注意力机制scSE和空洞卷积来改进轻量级网络ShuffleNetV2,并利用改进后的轻量级网络代替原YOLOv5s中主特征提取网络。实验结果表明,在实验设置相同的条件下,改进后的算法在模型从27.4 MB缩减到14.2 MB的情况下,检测精准率从97.86%提高到98.46%。     

迭代学习初态问题研究及其在机器人中的应用

在迭代学习控制研究中,通常的一个假设是：系统每次迭代初态与理想初态相等。这个假设对于系统的稳定性分析是非常重要的,因为迭代初态扰动将直接影响到迭代学习控制的跟踪精度。针对此问题,本文提出了一种新的迭代学习控制方法：利用遗忘因子控制初态偏移的影响,在保证系统迭代收敛的前提下,同时对初态进行学习,使其最终趋于理想初态,从而实现非线性系统对期望轨线的严格跟踪。最后,本文所提出方法在机器人模型中的仿真应用表明了本文方法的有效性。     

云南东川地区播卡金矿成矿规律研究

对云南播卡矿田金矿成矿规律进行研究,旨在有效指导下一步勘查工作。在前人工作的基础上,采用野外调查与前人资料二次开发相结合的方法,总结了新山—马家沟金矿床特征,分析了新山—马家沟金矿床控矿因素,探讨了金矿物质来源及形成机制,得出新山—马家沟金矿床类型为破碎蚀变岩型,建立了新山—马家沟金矿找矿标志,可有效指导下一步勘查工作。     

食品防腐剂对肠道菌群和宿主健康的影响研究进展

食品防腐剂具有强且广谱的抑菌性,在食品工业领域被广泛应用。食品防腐剂经膳食摄入后对肠道菌群和宿主健康的影响虽已有报道,但仍缺乏系统的总结。本文综述近年来国内外有关食品防腐剂与肠道菌群的最新研究成果,发现食品防腐剂通过改变肠道菌群多样性、调节肠道条件致病菌和有益菌丰度,进而影响机体脂代谢、免疫及肠道炎症;此外,展望了食品防腐剂未来的研究发展趋势。本文旨在引起广大科研工作者和读者对“食品防腐剂-肠道菌群-宿主健康”关系链的关注和重视,为目前已有的食品防腐剂的安全评价体系提供新视角、新思路,对维持人体健康具有一定的指导意义。     

基于红外谱图的低发射率涂层用基体树脂的判定方法

提出一种以吸光度系数为指标来筛选低发射率涂层用基体树脂的判定方法。从分析丙烯酸树脂、环氧树脂和聚氨酯树脂3种树脂的傅里叶红外光谱入手,根据 Lambert-Beer 定律对3种树脂的红外光谱进行定量分析,得出树脂在8～14mm 波段的吸光度系数曲线,并且积分求得3种树脂在该波段的平均吸光度系数。通过比较分析,丙烯酸树脂的吸光度系数最小,为0.0293mm－1,制得的清漆涂层的红外发射率最低,为0.90,适合作为低发射率涂层用基体树脂;最后,建立红外辐射一维传输模型,推导涂层红外发射率理论公式,理论证明了以吸光度系数为判定指标的合理性。     

AaZFP3, a Novel CCCH-Type Zinc Finger Protein from Adonis amurensis,Promotes Early Flowering in Arabidopsis by Regulating the Expression of Flowering-Related Genes

CCCH-type zinc finger proteins (ZFP) are a large family of proteins that play various important roles in plant growth and development; however, the functions of most proteins in this family are uncharacterized. In this study, a CCCH-type ZFP, AaZFP3, was identified in the floral organ of Adonis amurensis. Quantitative real-time PCR (qPCR) analysis revealed that AaZFP3 was widely expressed in the flowers of A. amurensis. Subcellular localization analysis showed that the AaZFP3 protein was mainly localized to the cytoplasm in tobacco and Arabidopsis. Furthermore, the overexpression of AaZFP3 promoted early flowering in Arabidopsis under both normal and relatively low-temperature conditions. RNA-sequencing and qPCR analyses revealed that the expression of multiple key flowering-time genes was altered in transgenic Arabidopsis overexpressing AaZFP3 compared to wild-type. Of these genes, FLOWERING LOCUS T (AtFT) expression was most significantly up-regulated, whereas FLOWERING LOCUS C (AtFLC) was significantly down-regulated. These results suggest that the overexpression of AaZFP3 promotes early flowering in Arabidopsis by affecting the expression of flowering-time genes. Overall, our study indicates that AaZFP3 may be involved in flowering regulation in A. amurensis and may represent an important genetic resource for improving flowering-time control in other ornamental plants or crops.