摘要：Broadband sound sink/absorber via a structure with deep sub-wavelength thickness is of great and continuing interest in physics and engineering *** intuitive technique extensively used is to combine components(resonators)with quasi-perfect absorption to piece together a broad absorbing band,but the requirement of quasi-perfect absorption substantially places a very strict restriction on the impedance and thickness of the ***,we theoretically and experimentally demonstrate that a compact broadband acoustic sink that quasi-perfectly absorbs broadband arriving sound waves can be achieved with coherently coupled‘‘weak resonances"(resonant sound absorbing systems with low absorption peaks).Although each component exhibits rather low absorption peak alone,via manipulating the coherent coupling effect among the components,they collectively provide a remarkably improved performance over a wide frequency range with a significantly compressed *** illustrate the design principle,a hybrid metasurface utilizing the coaction of parallel and cascade couplings is presented,which possesses an average absorption coefficient of 0.957 in the quasi-perfect band(a>0:9)from 870 to 3224 Hz with a thickness of only 3.9 *** results open new avenues for the development of novel and highly efficient acoustic absorbers against low frequency noise,and more essentially,suggest an efficient approach towards on-demand acoustic impedance engineering in broadband.

摘要：The solid-state magnetic cooling(MC)method based on the magnetocaloric effect(MCE)is recognized as an environmentally friendly and high-energy-efficiency *** search or design of suitable magnetic materials with large MCEs is one of the main targets at *** this work,we apply the chemical and hydrostatic pressures in the Ni_(35)Co_(15)Mn_(35-x)Fe_(x)Ti_(15) all-d-metal Heusler alloys and systematically investigate their crystal structures,phases,and magnetocaloric performances experimentally and *** the alloys are found to crystallize in an ordered B2-type structure at room temperature and the atoms of Fe are confirmed to all occupy at sites Mn(B).The total magnetic moments decrease gradually with increasing Fe content and decreasing of volume as *** martensitic transformation temperature decreases with the increase of Fe content,whereas increases with increasing hydrostatic ***,obviously enhanced magnetocaloric performances can also be obtained by applied *** maximum values of magnetic entropy change and refrigeration capacity are as high as 15.61(24.20)J(kg K)^(−1) and 109.91(347.26)J kg^(−1) withΔH=20(50)kOe,*** magnetocaloric performances are superior to most of the recently reported famous materials,indicating the potential application for active MC.

摘要：A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel *** mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio *** model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor *** large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the *** the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 *** study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas.

摘要：局域共振带隙和Bragg带隙可同时存在于超材料梁中,利用两种带隙之间的相互耦合效应可以实现超宽耦合带隙设计,在宽带减振领域极具应用潜力.以往研究通常考虑单振子超材料梁的单阶耦合带隙设计,因而只能实现单阶的超宽耦合带隙,无法满足双目标或多目标频带的宽带减振需求.为此,本文开展了双振子超材料梁的双阶耦合带隙调控设计研究,提出了一种实现双阶耦合宽带隙的设计方法,分析了所设计双阶耦合带隙相比传统单阶耦合带隙的带宽优势,并探究了双振子质量分配比对双阶耦合带隙总宽度的影响,进一步设计出最优的质量分配比,使得实现的双阶耦合带隙的总宽度最宽.此外,还采用谱元法研究了基于双阶耦合带隙设计的双振子超材料梁的减振特性,通过与有限元法进行对比,验证了谱元法的准确性,研究表明基于双阶耦合带隙设计可以实现两个宽频带范围的高效减振.

摘要：高催化活性的催化材料是提升铝-空气电池阴极氧还原反应(ORR)的必要条件,设计并制备了石墨烯基钙钛矿型催化材料,测试了其电化学性能并组装了铝-空气电池,借助第一性原理研究了催化作用机理。通过科研问题设计和合作研究实践完成基于科研驱动的PBL教学模式实践。结果表明:溶胶-凝胶法制备的掺杂钙钛矿与石墨烯负载,可有效提高导电性和电催化活性,保持电池高稳定放电。该实验从材料制备、电池组装、电子结构分析等方面设计和调控催化性能,使学生掌握了材料制备基本实验技能和电池测试综合应用能力,并引入了材料设计创新性研究成果,实现从理论到实践再到理论的飞跃。PBL教学激发了学生创意意识和科研兴趣,提高了团队合作和综合能力。

摘要：《花篮图》作为宋代院体画的一种特殊题材,不仅展现了宋代插花艺术的繁荣和兴盛,也反映了文人士大夫在花艺中的审美追求。文章从符号学的视角对宋代李嵩四季《花篮图》进行视觉元素的提取与分析,挖掘宋代花卉文化背后的符号意义,把握其造型特征和文化内涵,通过物质层“形”及精神层“意”的转译手法,进行在丝巾中的设计转译应用。本次设计转译在传承传统花卉文化的基础上,融入现代审美需求,使花卉审美文化更好地融入现代生活,实现宋韵文化的创造性转化和创新性发展。

摘要：集成方法是不平衡学习方法的重要分支,然而,现有不平衡集成方法均作用于原样本而没考虑样本的结构信息,因此其效能仍然有限.样本的结构信息包括局部和全局结构信息.为了解决上述问题,本文提出了一种基于深度样本包络网络(Deep Instance Envelope Network,DIEN)和分级结构一致性机制(Hierarchical Structure Consistency Mechanism,HSCM)的不平衡集成学习算法.该算法在考虑局部流形和全局结构信息的情况下,通过多层样本聚类,生成高质量的多层包络样本,从而实现类平衡化.首先,算法基于样本近邻拼接和模糊C均值聚类算法,设计DIEN来挖掘样本的结构信息,得到深度包络样本.然后,设计局部流形结构度量和全局结构分布度量来构建HSCM用于增强层间样本的分布一致性.接着,将DIEN和HSCM结合起来,构建出优化后的深度样本包络网络——DH(DIEN with HSCM).之后,将基分类器应用于包络样本.最后,设计bagging集成学习机制来融合基分类器的预测结果.文末组织了多组实验,采用了十多个公共数据集和有代表性的相关算法进行验证比较.实验结果表明,本文算法在AUC(Area Under Curve),F-measure等四个性能指标上显著最优.

摘要：随着课程思政教学改革不断深化,如何客观准确地评价课程思政教学效果成了亟待解决的问题。基于美国教育评价家斯塔弗尔·比姆倡导的课程评价模式(简称为CIPP模式),以安徽科技学院“广告学”课程思政建设为契机,构建“广告学”课程思政教学效果评价指标体系,并用于具体的课程思政评价中,提出加强师资队伍建设、加大课程思政经费投入、积极拓展课程思政教学新场景等建议,为改进课程思政教学质量,提高教学效果提供有益的参考。

摘要：本文以多枚空空导弹逆轨拦截高速运动目标为背景,提出了一种以协同探测为终端约束的分布式协同中制导律.通过对误差源和误差传递链路进行分析,建立了中末交班概率计算模型,基于虚拟导引点研究了协同视场拼接方法.在视线法向,针对位置协同和角度协同等约束条件,设计了基于高斯伪谱法的最优制导律.在视线方向,基于二阶多智能体一致性理论,设计了分布式时间协同制导律,构造李雅普诺夫泛函证明了该方法可使系统在有限时间达到稳定,并推导出了一致性时间上界.仿真结果表明该制导律可使多弹以各自期望的视线角同时到达指定交班区域,实现视场拼接、协同探测的需求,有效提高了中末交班概率.

摘要：融媒体时代播音与主持艺术专业课程思政教育面临前所未有的挑战与机遇,鉴于此,文章从融媒体时代播音与主持艺术专业课程思政教育的必要性出发,探讨了当前课程思政教育实施中面临的困境,并提出了一系列路径优化策略。首先,文章强调融媒体时代播音与主持艺术专业的学生需要具备高度政治觉悟和媒体素养,因此课程思政教育的必要性进一步凸显。随后,通过深刻分析当前面临的困境,指出教学模式局限、方式生硬以及平台单一等限制了思政教育与专业教育的有机融合。在路径优化策略方面,文章提出明确课程思政教学目标的重要性,在高校领导和教师团队充分沟通的基础上,学生能够深刻理解课程思政建设对他们未来职业生涯发展的重要影响;主张将思政要素融入课堂教学,强调在融媒体时代背景下播音主持教学与时事紧密结合;建设实践平台,使学生能对思政要素与专业教学的融合产生更直观的感受;搭建思政教育平台,借助线上线下的交互式平台,展示和传播专业实践中融入思政要素的作品。文章提出的路径优化策略旨在全面提升播音与主持艺术专业课程的思政教育成效,使学生在接受专业技能培养的同时更好地接受思政教育,从而进一步适应融媒体时代的需求,培养具有高度政治觉悟和媒体素养的人才。