摘要：The effects of Sn content on microstructure and tensile properties of as-cast and as-extruded Mg-8Li-3Al-(1,2,3)Sn(wt.%)alloys were investigated by X-ray diffractometry(XRD),optical microscopy(OM),scanning electron microscopy(SEM)and tensile *** is found that,as-cast Mg-8Li-3Al-(1,2,3)Sn alloys consist ofα-Mg+β-Li duplex matrix,MgLiAl2 and Li2Mg Sn *** Sn content leads to grain refinement ofα-Mg dendrites and increase in content of Li2MgSn *** hot extrusion,complete dynamic recrystallization(DRX)takes place inβ-Li phase while incomplete DRX takes place inα-Mg *** Sn content is increased,the volume fraction of DRXedα-Mg grains is increased and the average grain size of DRXedα-Mg grains is *** Sn content is beneficial to strength but harmful to ductility for as-cast Mg-8Li-3Al-(1,2,3)Sn *** properties of Mg-8Li-3Al-(1,2,3)Sn alloys are improved significantly via hot extrusion and Mg-8Li-3Al-2Sn alloy exhibits the best tensile properties.

摘要：针对现有电液伺服系统的非线性、参数不确定导致轨迹跟踪精度低的问题,提出了一种非线性自适应输出反馈控制器。分析了液压系统的非线性模型,为控制器设计提供理论基础。非线性自适应输出反馈控制器包含自适应线性扩展状态观测器(Linear Extended State Observer, LESO)和非线性扰动观测器(Nonlinear Disturbance Observer, NDO),用来估计系统中不可策略状态以及惯性载荷动力学中的失配扰动。实验结果表明,所提出的非线性自适应输出反馈鲁棒控制器可有效解决PI控制器存在的谐振问题。

摘要：文章通过构建知识图谱的方法,以CNKI数据库有关图形创意设计研究领域为对象,利用CiteSpace可视化分析工具对图形创意相关文献关键词、领域和趋势,深入分析了2013~2023年图形创意的研究热点和发展趋势。研究表明,图形创意领域的发展研究经历快速上升后又缓慢下降的趋势,知识图谱清晰地展现了此阶段内图形创意的研究热点和趋势主要围绕平面、广告、包装、服装等设计领域和教育领域展开。随着数字化和新技术的快速发展,图形创意在未来的发展趋势则偏向于人工智能、虚拟现实和增强现实等技术的融合。

摘要：V_(2)O_(5),which has multicolor and energy storage properties,is a promising electrochromic material for multifunctional electrochromic devices,but its practical application is limited by its poor lifespan and long switching *** this work,high-performance V_(2)O_(5)/TiO_(2)films were fabricated by spraying a V_(2)O_(5)solution on in situ-grown TiO_(2)*** to the porous structure formed between the TiO_(2)nanorods and the remarkable electron transfer performance of TiO_(2),the switching time of the V_(2)O_(5)/TiO_(2)films ***,the strong adhesion between the TiO_(2)nanorods and F-doped tin oxide(FTO)glass and the increased surface roughness of the substrates significantly improved the cycling stability of the V_(2)O_(5)/TiO_(2)*** a large transmittance modulation(47.8%at 668 nm),fast response speed(τ_(c)=5.1 s,τ_(b)=4.2 s),and long lifespan,V_(2)O_(5)/TiO_(2)films were used as electrodes for the electrochromic energy storage device(EESD),which switched in six colors through color overlay:dark orange,sandy yellow,green-yellow,yellow-green,dark green,and dark *** by pixel displays,EESDs were designed by segmenting V_(2)O_(5)films to stagger the display of the electrochromic and ion storage layers,which presented 11 types of information based on different combinations of *** work provides inspiration for developing multifunctional electrochromic devices,especially for camouflage and information displays.

摘要：叶轮式血液泵LAP-Ⅰ采用了航空叶轮机械中使用的设计思想方法,该装置是针对亚洲患者的临床应用而设计.综合航空叶轮机械技术和医学需求,采用整体转子和悬臂静子结构设计,并对其串列叶栅静子结构做了进一步的优化改进,得到叶轮式血液泵LAP-Ⅱ.计算流体动力学(CFD)模拟结果表明,血泵LAP-Ⅱ的压升性能达到医学需求,泵体内流动状况顺畅.最大比较剪切应力(S)值得到明显降低,流线显示血液通过泵体的最长时间得到减小,抗溶血应用性能得到提高.

摘要：通过光栅原理将动态画面用于织物设计时,易出现织物的双层结构复杂、色彩难以精准控制等问题,提出基于光栅动画图案合成原理设计动态图案光纤织物,利用提花工艺将光纤和纱线织造成图案织物,使用发光二极管作为光源,通过热塑管将其分别与聚合物光纤耦合连接,利用发光控制器,使得二极管依次间隔发光,显示相邻动作的静态图案。还分析了合成图片个数、切分用光栅细度、分组发光频率等对图案动态效果的影响。以光纤和棉纱为原料,采用提花织机设计和织造聚合物光纤织物,结果表明:当以直径为0.25 mm的聚合物光纤作为最小发光单元时,5帧数合成的光纤发光织物能够同时兼顾动画呈现的识别度和流畅度;间隔条纹宽度在0.25 mm时,动态效果呈现时,物体轮廓越清晰;当发光频率为0.2 s时,其呈现的动态效果最好。该思路开拓了织物上动态图案呈现的全新实现方法。

摘要：Because of its high purity and excellent orientation, mesophase pitch is a superior precursor for high-performance car-bon materials. However, the preparation of top-notch mesophase pitch faces challenges. Catalytic polycondensation at low temperat-ures is more favorable for synthesizing mesophase pitch, because it circumvents the high-temperature free radical reaction of other thermal polycondensation approaches. The reaction is gentle and can be easily controlled. It has the potential to significantly im-prove the yield of mesophase pitch and easily introduce naphthenic characteristics into the molecules, catalytic polycondensation is therefore a preferred method of synthesizing highly spinnable mesophase pitch. This review provides a synopsis of the selective pre-treatment of the raw materials to prepare different mesophase pitches, and explains the reaction mechanism and associated research advances for different catalytic systems in recent years. Finally, how to manufacture high-quality mesophase pitch by using a cata-lyst-promoter system is summarized and proposed, which may provide a theoretical basis for the future design of high-quality pitch molecules.

摘要：针对非连续变形分析中开合迭代难以收敛的难题,基于块体接触约束状态和块体位移之间的关系,提出了基于逼近阶跃函数和拉格朗日插值的改进DDA方法。采用双曲正切函数来逼近阶跃函数,利用阶跃函数将块体接触约束状态用块体位移来表达,以此来替代开合迭代,避免了开合迭代难以收敛的难题。利用拉格朗日插值原理,推导得到只含有块体位移为未知量的块体系统势能函数,并利用变尺度法来求解总体势能函数的极值以得到块体位移。分别结合滑块模型和地下洞室模型,分析了改进DDA方法的计算精度和计算速度,验证了文中提出的改进DDA方法的正确性和稳定性。研究表明:基于逼近阶跃函数和拉格朗日插值的改进DDA方法具有较高的精度,且相比较传统DDA方法而言,具有更为稳定的和更为强健的计算收敛性。因此,基于逼近阶跃函数和拉格朗日插值的改进DDA方法是一种稳定有效的数值计算方法,为解决非连续变形中开合迭代难以收敛的问题提供了新思路。

摘要：具有复杂工艺路线的装备产品,其生产系统设计的待决策变量之间通常相互耦合、相互影响,对产品最终的批产成本产生着影响,构成了较为复杂的组合优化问题。对此,提出一种基于动态成本卷积的复杂产品批产路径优化模型。该模型考虑了复杂产品工艺路线的各节点均可能存在多种生产设计选项,在各选项对应着不同生产投入和批量效率的情况下,以最终交付产品的批产成本最小化为目标输出生产系统设计和成本卷积路径。同时,建立了混合整数规划模型,并通过对模型中非线性成分实施可控精度线性化,将模型换化为可最优求解的线性模型。最后,针对某连续生产行业设计了小、中、大规模实验算例,验证了所提模型的可行性、合理性和求解效率。

摘要：浮式风电缩比实验一般采用传统的推力系数相似理论进行模型设计。模型机组可再现原型机组平均推力,但功率性能偏低,且动态气动相似性难以保证。本文提出一种基于最优叶尖速比映射关系的新型动态气动相似理论,并以NREL5-MW为原型机组,分别设计了传统理论和新理论下的两款模型机组。与传统模型机组相比,新模型机组除了满足推力系数相似,功率系数也可通过增加某常数与原型机组近似。纵荡-纵摇组合运动下的计算结果表明:相同的叶尖速比变化下,新模型机组的动态推力、动态功率及其系数与原型机组的相似性明显优于传统模型机组。本工作适用于风洞实验研究,可在一定程度上解决水池实验中模型机组气动性能不够准确的问题。