摘要：This paper is concerned with the scaled formation control problem for multi-agent systems(MASs)over fixed and switching ***,a modified resilient dynamic event-triggered(DET)mechanism involving an auxiliary dynamic variable(ADV)based on sampled data is *** the proposed DET mechanism,a random variable obeying the Bernoulli distribution is introduced to express the idle and busy situations of communication ***,the operation of absolute value is introduced into the triggering condition to effectively reduce the formation ***,a scaled formation control protocol with the proposed resilient DET mechanism is designed over fixed and switching *** scaled formation error system is modeled as a time-varying delay ***,several sufficient stability criteria are derived by constructing appropriate Lyapunov-Krasovskii functionals(LKFs).A co-design algorithm based on the sparrow search algorithm(SSA)is presented to design the control gains and triggering parameters ***,numerical simulations of multiple unmanned aerial vehicles(UAVs)are presented to validate the designed control method.

摘要：Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al *** accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high thermal ***,databases for predicting temperature-and composition-dependent thermal conductivities must be *** this study,Mg-Al-La alloys with different contents of Al2La,Al3La,and Al11La3phases and solid solubility of Al in the α-Mg phase were *** influence of the second phase(s) and Al solid solubility on thermal conductivity was *** results revealed a second phase transformation from Al_(2)La to Al_(3)La and further to Al_(11)La_(3)with the increasing Al content at a constant La *** degree of the negative effect of the second phase(s) on thermal diffusivity followed the sequence of Al2La>Al3La>Al_(11)La_(3).Compared with the second phase,an increase in the solid solubility of Al in α-Mg remarkably reduced the thermal *** the basis of the experimental data,a database of the reciprocal thermal diffusivity of the Mg-Al-La system was established by calculation of the phase diagram (CALPHAD)*** a standard error of±1.2 W/(m·K),the predicted results were in good agreement with the experimental *** established database can be used to design Mg-Al alloys with high thermal conductivity and provide valuable guidance for expanding their application prospects.

摘要：本文介绍了一种通过调整卡箍使得管道避免发生共振的设计策略.当管道的固有频率在机械设备运作时产生的振动频率范围内,会引发共振现象,给机械设备的正常操作带来严重的灾难.因此,把机械设备操作产生的振动频率范围定义为频带禁区.通常,工程中的管道被简化为多跨输流管道:通过将卡箍简化为线性和扭转刚度,建立了多跨输流管道的整体管道模型.通过采用Galerkin截断方法并应用广义特征值方法,获得了多跨输流管道的固有频率.通过对比不同长度的管道固有频率和频带禁区,定义了管长的安全范围和共振范围分别为频带禁区的外和内,并且通过分析卡箍的影响推导得出了绝对安全长度和绝对共振长度.此外,还确定了卡箍刚度和位置对安全范围的影响.结果表明,通过调整卡箍的线性刚度、扭转刚度和位置,管道的安全范围会发生显著地变化.根据这些结果,提出了一种管道设计策略,从而避免了管道的共振发生,并减少了使用卡箍的数量.最后,以飞机上的一段管道为例进行了设计,结果表明:通过调整卡箍,管道的固有频率成功地远离了频带禁区,因而在飞机的运行过程中不会发生共振.总而言之,通过调整卡箍的刚度或位置,可以获得避免多跨输流管道发生共振的设计策略.

摘要：Ni/TiO_(2) catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO_(2) remains *** this work,the rutile/anatase ratio in supports was successfully controlled by varying the calcination temperature of anatase-TiO_(2).Structural characterizations revealed that a distinct TiO_(x) coating on the Ni nanoparticles(NPs)was evident for Ni/TiO_(2)-700 catalyst due to strong metal-support *** is observed that the TiOx overlayer gradually disappeared as the ratio of rutile/anatase increased,thereby enhancing the exposure of Ni active *** exposed Ni sites enhanced visible light absorption and boosted the dissociation capability of CH4,which led to the much elevated catalytic activity for Ni/TiO_(2)-950 in which rutile ***,the catalytic activity of solar-driven DRM reaction was significantly influenced by the rutile/anatase ***/TiO_(2)-950,characterized by a predominant rutile phase,exhibited the highest DRM reactivity,with remarkable H2 and CO production rates reaching as high as 87.4 and 220.2 mmol/(g·h),*** rates were approximately 257 and 130 times higher,respectively,compared to those obtained on Ni/TiO_(2)-700 with *** study suggests that the optimization of crystal structure of TiO_(2) support can effectively enhance the performance of photothermal DRM reaction.

摘要：机机翼前缘结冰会改变机翼的气动轮廓并影响整体的空气动力学性能.研究简化角冰冰形对翼型绕流流场结构的影响可以为飞机防冰设计提供有价值的参考.采用粒子图像测速技术,在低速直流风洞中对覆盖不同角冰冰形的翼型在不同攻角时的流场结构进行了详细的实验测量.实验对象包括三种简化的冰形和原始冰形.结果表明,在本研究范围内,覆盖简化冰形的翼型和覆盖原始冰形的翼型在流场参数上的最大差异为35.11%.与原始冰形相比,覆盖简化的角冰冰形的翼型流场中的分离泡距离翼型前缘和后缘更远.在三种冰形简化方法中,将冰角简化成矩形并在冰角之间添加抛物线的连接方式具有比较好的简化效果.在选定的两个区域中,这种简化冰形和原始冰形在翼型绕流流场的参数平均值的差异在14.88%之内.

摘要：临床上常用的广谱抗生素无法有效解决抗生素高度耐药ESKAPE菌感染的难题,ESKAPE耐药菌已经成为人类生命健康的重大威胁.抗生素与佐剂的联合治疗是解决抗生素耐药菌感染的重要途径,但是探索对所有ESKAPE耐药菌都具有广谱和高效抗菌活性的抗生素-佐剂组合仍然面临巨大挑战.在这里,我们提出了一种抗生素-佐剂的有效设计策略,将对ESKAPE中耐药阴性菌具有高活性的多粘菌素B(PMB)与模拟宿主防御肽的细菌膜靶向阳离子聚(2-噁唑啉)相结合.我们通过2-噁唑啉单体可控聚合,合成了一系列具有不同疏水性侧链的阳离子聚(2-噁唑啉).研究表明,聚(2-噁唑啉)和PMB的组合效果随着聚(2-噁唑啉)侧链疏水性的提高呈现出从拮抗效应到协同效应的逐渐变化.其中,优选的聚(2-噁唑啉)EACA-POX_(20)显著增强了PMB的抗菌活性,尤其是对于ESKAPE耐药阳性菌的抗菌活性增强了16–32倍.聚(2-噁唑啉)EACA-POX_(20)有效增强了PMB的抗菌活性并扩展了PMB的抗菌谱.聚(2-噁唑啉)和PMB的组合策略能够有效对抗所有耐药ESKAPE病原体,为解决ESKAPE耐药菌提供了新的思路.

摘要：本研究成功构建了具有切割DNA能力的双金属枝状大孔金属有机框架(MOFs;HMUiO-66(Zr/Ce)),并将其用于高效破坏生物膜并抑制细菌生长.通过改变Zr/Ce的投料比,可在0-69%的范围内精确调控Zr/Ce的引入量,并控制其粒径在1μm-150 nm之间.HMUiO-66(Zr/Ce)具有独特的化学和热稳定性,开放的大孔结构和可接近的Lewis酸活性位点,表现出模拟DNA酶活性.双金属MOFs中丰富的Zr-OH位点能有效地捕获核酸,而相邻的Ce-OH基团对磷氧键形成亲核攻击,协同放大DNA的水解速率,使得开发的HMUiO-66(Zr/Ce)能够作为切割细胞外DNA和清除细菌生物膜的纳米药物.在此基础上,我们设计了一种仿生HMUiO-66(Zr/Ce)/PVDF膜,该生物膜可抑制细菌粘附和定植,在抗菌治疗和医疗器械中具有广阔的应用前景.

摘要：由于C=C双键交联反应机制的成熟,金属氧化物光刻胶得到了广泛的发展.然而,由于不稳定的C=C双键,这种材料需要低温和遮光存储.在此,首次在金属氧簇中提出了C-F键交联策略用于光刻图案化.以光刻胶Zn-TBA为例,它形成光滑无缺陷的薄膜,且表面粗糙度Rq小于0.2 nm.使用极紫外(EUV)干涉掩模,在65 mJ cm^(-2)曝光剂量下形成37.5 nm的半周期(HP)图案.在EUV曝光和正己烷显影后,通过原子力显微镜(AFM)观察到负性光刻胶形貌.重要的是,Zn-TBA可以在室温和明亮的环境中储存.除了脱羧之外,我们还提出光引发的C-F交联是Zn-TBA图案的主要贡献者,并通过高分辨率X射线光电子能谱(HRXPS)和密度泛函理论(DFT)计算得以证明.这种新颖的光刻机制为下一代金属基材料的设计提供了新的思路.

摘要：A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is *** the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are *** feedforward controller is a novel input rate-dependent neural network hysteresis inverse model,while the feedback controller is a proportion integration differentiation(PID)*** the proposed inverse model,an input ratedependent auxiliary inverse operator(RAIO)and output of the hysteresis construct the expanded input space(EIS)of the inverse model which transforms the hysteresis inverse with multi-valued mapping into single-valued mapping,and the wiping-out,rate-dependent and continuous properties of the RAIO are analyzed in *** on the EIS method,a hysteresis neural network inverse model,namely the dynamic back propagation neural network(DBPNN)model,is ***,a hybrid compensation scheme for the PEAs is designed to compensate for the ***,the proposed method,the conventional PID controller and the hybrid controller with the modified input rate-dependent Prandtl-Ishlinskii(MRPI)model are all applied in the experimental *** results show that the proposed method has obvious superiorities in the performance of the system.

摘要：作为细胞中的主要运输系统,天然囊泡在物质的定点输运过程中具有至关重要的作用.高分子囊泡是与之结构相似的一种人工囊泡,具有优异的膜稳定性和胶体稳定性、高药物负载率、低膜穿透性、优异的可修饰性和长循环时间等优势,在生物医用领域具有广泛的应用前景.然而,目前该领域尚面临一系列重要挑战,如合成和制备方法较为复杂、生物相容性较难预测、功能和递送途径有限等,限制了其临床转化之路.本文从囊泡的构建模块合成、自组装技术和潜在的生物医学应用等角度,提出了设计和制备下一代高分子囊泡需要解决的五个关键科学问题,指出了未来面临的重要挑战和发展方向,例如简化设计和合成过程,优化和规范自组装过程,拓展潜在的应用前景.