基于虚拟训练序列的双向水声信道精准估计

针对时变水声信道造成的严重多途干扰问题,提出基于虚拟训练序列的双向水声信道精准估计(Virtual Training Based Bidirectional Channel Estimation,VT-BCE)算法。基于叠加训练(Superimposed Training,ST)方案,将训练序列和符号序列线性叠加,使得训练序列和符号序列的信道信息一致,提高信号的跟踪能力;基于置信传播,双向信道估计(Bidirectional Channel Estimation,BCE)算法将一个数据块分成多个短块,利用整个数据块的信息估计当前短块信道,实现对当前短块的精准信道估计。将ST方案、BCE算法和信道均衡(频域)以迭代的方式相结合,使估计的符号序列可以作为信道估计的虚拟训练(Virtual Training,VT)序列,提升信道的估计性能,进而提高系统的解码性能。最后,通过计算机仿真和水池试验,验证了所提算法的有效性。

动态信任视角下消费金融信息产品设计与评价

目的 随着科技和数字化的发展,消费金融信息产品在现代经济和金融体系中扮演着愈发重要的角色。本文旨在探究消费金融信息产品用户体验因素,优化体验设计与评价方法。方法 基于用户动态信任需求,以在校大学生为调研对象发放问卷,以284个有效数据为研究样本,使用SPSS软件进行量化分析,基于数据结论进行消费金融产品交互设计,并从动态信任视角构建消费金融信息产品设计评价模型。结果 依据产品评价多层次指标模型,获取设计与评价指标权重,并得出消费金融信息产品体验的总体评分。结论 结合用户动态信任视角对消费金融信息产品进行设计与评价,可有效地对产品进行量化设计与检验,强化产品与用户间的信任关系,在动态交互过程中获取用户变化的需求,改善人机信任关系,提高产品的持续改进能力。

老年人心智模型研究及在交互设计领域的应用

目的对面向老年人群的心智模型研究及其在信息交互设计领域的应用现状进行分析梳理,以对相关领域的理论研究与应用建立较为全面的认识。方法基于文献可视化工具,对国内外2000—2020年收录的面向老年人群的心智模型研究及其主要应用文献进行收集、整理与可视化分析,通过代表性文献、关键词和引文的聚类、突现和共现等方法进行整体分析。结论心智模型理论正在成为信息科技产品交互设计研究的理论基础,对高科技产品的适老化设计具有重要的指导作用。目前面向老年人群的心智模型相关研究主要聚焦于在特定交互场景下,生理和心理的变化对老年人心智模型绩效的影响以及如何构建老年人心智模型等方面,相关基础理论及应用研究仍待深入发展,进一步提炼老年人群心智模型的共性特征及探索更具普适性的心智模型构建方法是未来的发展方向,对老年人适应智慧生活具有重要意义。

基于认知负荷理论的雷达信息视图交互设计策略研究

目的以降低操作者认知负荷为目标从人机认知任务分配角度探讨雷达界面信息图的交互设计策略。方法对基于雷达信息图的系统观察任务流程进行分析,基于新型人机协同、人机合作视角探讨系统人机功能分配的原则,采用认知负荷评测方法,通过用户绩效测量和NASA-TLX量表,采集分析任务完成的时间、正确率及认知负荷水平,比较不同的人机分工方案对操作者认知负荷的影响。结果基于新的人机功能分配策略的设计方案中,用户完成时间、正确率均大于初始方案,完成任务的认知负荷小于初始设计方案。结论复杂信息界面的信息呈现与交互设计,可以通过系统功能在人机之间的合理分配,充分发挥人机各自优势,降低操作者的认知负荷,提高观测准确率,提高系统绩效。

碳纤维增强陶瓷基复合材料高温拉伸性能研究

为进一步提高以碳化硅为主要基体的陶瓷基复合材料的高温力学性能,对材料高温拉伸性能的变化规律和影响因素进行了评价和分析。结果表明,随着温度的升高材料拉伸性能呈现先上升后下降的变化趋势,碳化硅基体结晶程度逐渐提高,晶粒尺寸逐渐长大并出现团聚,导致内部缺陷孔洞增多,造成材料高温性能下降;材料热处理温度、致密化度的提高对材料的高温性能具有改善作用,使材料在经历最高温度2000℃,总时长3000s热环境条件下测试时性能保留率达82.4%。

MAP kinase gene STK1 is required for hyphal, conidial, and appressorial development, toxin biosynthesis, pathogenicity, and hypertonic stress response in the plant pathogenic fungus Setosphaeria turcica

The mitogen-activated protein kinase （MAPK）, a key signal transduction component in the MAPK cascade pathway, regulates a variety of physiological activities in eukaryotes. However, little is known of the role MAPK plays in phytopathogenic fungi. In this research, we cloned the MAPK gene STK1 from the northern corn leaf blight pathogen Setosphaeria turcica and found that the gene shared high homology with the high osmolality glycerol （HOG） MAPK gene HOG1 of Saccharomy- ces cerevisiae. In addition, gene knockout technology was employed to investigate the function of STKI. Gene knockout mutants （KOs） were found to have altered hyphae morphology and no conidiogenesis, though they did show similar radial growth rate compared to the wild-type strain （WT）. Furthermore, microscope observations indicated that STK1 KOs did not form normal appressoria at 48 h post-inoculation on a hydrophobic surface. STK1 KOs had reduced virulence, a significantly altered Helminthosporium turcicum （HT）-toxin composition, and diminished pathogenicity on the leaves of susceptible inbred corn OH43. Mycelium morphology appeared to be significantly swollen and the radial growth rates of STK1 KOs declined in comparison with WT under high osmotic stress. These results suggested that STK1 affects the hyphae development, conidiogenesis, and pathogenicity of S. turcica by regulating appressorium development and HT-toxin biosynthesis. Moreover, the gene appears to be involved in the hypertonic stress response in S. turcica.

Stk2,a Mitogen-Activated Protein Kinase from Setosphaeria turcica,Specifically Complements the Functions of the Fus3 and Kss1 of Saccharomyces cerevisiae in Filamentation,Invasive Growth,and Mating Behavior

Setosphaeria turcica,an essential phytopathogenic fungus,is the primary cause of serious yield losses in corn; however,its pathogenic mechanism is poorly understood.We cloned STK2,a newly discovered mitogen-activated protein kinase gene with a deduced amino acid sequence that is 96% identical to MAK2 from Phaeosphaeria nodorum,56% identical to KSS1 and 57% identical to FUS3 from Saccharomyces cerevisiae.To deduce Stk2 function in S.turcica and to identify the genetic relationship between STK2 and KSS1/FUS3 from S.cerevisiae,a restructured vector containing the open reading frame of STK2 was transformed into a fus3/kss1 double deletion mutant of S.cerevisiae.The results show that the STK2 complementary strain clearly formed pseudohyphae and ascospores,and the strain grew on the surface of the medium after rinsing with sterile water and the characteristics of the complementary strain was the same as the wild-type strain.Moreover,STK2 complemented the function of KSS1 in filamentation and invasive growth,as well as the mating behavior of FUS3 in S.cerevisiae,however,its exact functions in S.turcica will be studied in the future research.

StKU80, a component in the NHEJ repair pathway, is involved in mycelial morphogenesis, conidiation, appressorium development, and oxidative stress reactions in Exserohilum turcicum

Homologous recombination(HR) and nonhomologous end joining(NHEJ) are considered the two main double-strand break(DSB) repair approaches in eukaryotes. Inhibiting the activities of the key component in NHEJ commonly enhances the efficiency of targeted gene knockouts or affects growth and development in higher eukaryotes. However, little is known about the roles of the NHEJ pathway in foliar pathogens. Here we identified a gene designated St KU80, which encodes a putative DNA end-binding protein homologous to yeast Ku80, in the foliar pathogen Exserohilum turcicum. Conserved domain analysis showed that the typical domains VWA, Ku78 and Ku-PK-bind are usually present in Ku70/80 proteins in eukaryotes and are also present in St Ku80. Phylogenetic analysis indicated that St Ku80 is most closely related to Ku80(XP001802136.1) from Parastagonospora nodorum, followed by Ku80(AGF90044.1) from Monascus ruber. Furthermore, the gene knockout mutants ΔSt KU80-1 and ΔSt KU80-2 were obtained. These mutants displayed longer septas, thinner cell walls, smaller amounts of substances on cell wall surfaces, and more mitochondria per cell than the wild-type(WT) strain but similar HT-toxin activity. The mutants did not produce conidia and mature appressoria. On the other hand, the mutants were highly sensitive to H2O2, but not to ultraviolet radiation. In summary, the St KU80 plays devious roles in regulating the development of E. turcicum.

血清中缺氧诱导因子1和脂蛋白相关磷脂酶2与患者冠状动脉粥样硬化斑块形态特征及心血管事件的关系

目的探讨冠心病患者血清中缺氧诱导因子 1( HIF-1α)和脂蛋白相关磷脂酶 2( PLA2)水平与患者动脉粥样硬化斑块形态特质及心血管事件的关系。方法以本院 2012 年 9 月- 2015 年 9 月收治的 86 例冠心病患者为研究对象,采用酶联免疫吸附法检测患者血清中 HIF-1α和 PLA2 水平,采用冠脉 CT 分析患者冠脉斑块的形态,探讨不同HIF-1α和 PLA2 水平患者动脉斑块类型和冠脉病变程度的关系,并采用 Logistic 回归分析探讨血清中 HIF-1α和 PLA2 水平与患者心血管事件风险的关系。结果 HIF-1α高水平组、PLA2 高水平组患者软斑块均明显低于对应低水平组,而钙化斑块明显高于低水平。HIF-1α高水平组、PLA2 高水平组患者单支病变均明显低于对应低水平,多支病变多于高水平,完全闭塞明显高于低水平组,轻度闭塞低于低水平组,差异均有统计学意义( P < 0. 05)。HIF-1α、 PLA2、软斑块、重度冠脉狭窄、多支冠脉病变是患者心血管事件的独立风险因素( P < 0. 05)。结论冠心病患者血清中HIF-1α和 PLA2 水平与患者冠脉病变程度和心血管事件密切相关。