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：α-Diimide catalysts have attracted widespread attention due to their unique chain walking characteristics.A series ofα-diimide nickel/palladium catalysts with different electronic effects and steric hindrances were designed and synthesized for olefin *** this work,we synthesized a series of asymmetricα-diimide nickel complexes with different steric hindrances and used them for ethylene *** nickel catalysts have high ethylene polymerization activity,up to 6.51×10^(6)g·mol^(−1)·h^(−1),and the prepared polyethylene has a moderate melting point and high molecular weight(up to 38.2×10^(4)g·mol^(−1)),with a branching density distribution between 7 and 94 branches per 1000 *** importantly,the polyethylene prepared by these catalysts exhibits excellent tensile properties,with strain and stress reaching 800%and 30 MPa,respectively.

摘要：Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

摘要：在智能凝胶防伪系统中使用的光、热、电、pH等刺激响应性水凝胶,是一种有前途的信息加密和解密材料.然而单一刺激会限制高水平的防伪.因此,需要协同使用多种刺激来提升信息安全等级.本研究设计了一种高透明度的海藻酸钠-聚丙烯酰胺(SA-PAM)水凝胶作为基体,利用无机变色材料钼酸铵(Mo7)赋予其凝胶光致变色特性.此外,温敏材料聚N-异丙基丙烯酰胺(PNIPAM)可使凝胶在最低临界相变温度(LCST)下发生体积相变,进而改变凝胶的宏观状态,可以通过调整凝胶体系中亲水单体和疏水单体的比例来控制LCST.利用紫外线(UV)作为“墨水”输入信息,以温度作为“开关”来加密/解密信息.总之,该水凝胶具有出色的光致变色能力,可在10 s内着色,紫外光吸收率最高可达96.23%.利用水凝胶对光-热刺激展现出的非凡响应能力,可以实现其迅速显示和隐藏信息的功能,从而确保信息安全,这为光致变色水凝胶在信息加密领域的应用提供了一种新方法.

摘要：A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as *** hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a ***,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo ***,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular *** key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the *** and multiple tissue compartments with different geometries can be established using either straight or curved DTB *** effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor *** a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan ***,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies.

摘要：化学取代是有效调节分子电导,产生多通道输运、量子干涉效应和其他机制的关键方法.但分子骨架和侧基之间存在复杂的相互作用,目前仍未被研究清楚.在本工作中,我们结合扫描隧道显微镜裂结实验技术和第一性原理计算方法,深入研究了具有不同σ和π侧基的分子电导.实验结果及理论分析表明,σ侧基的加入引起了分子前线轨道的对称性破缺并加剧了分子内散射,从而导致电导的降低.相反,π侧基引入了额外的电荷传输通道,实现了电荷传输的多通道效应,增加了分子的电导.这些发现为未来分子功能化和分子电子器件的设计提供了坚实的基础.

摘要：应用3D打印技术制备准固态微型超级电容器(MSCs)在可编程结构设计和高质量负载电极制造方面具有固有的优势.然而,缺乏高性能的可打印墨水和厚电极内缓慢的离子传输,对其实际电荷存储能力提出了重大挑战.本文成功开发了一种具有优异流变性能的新型NiCo_(2)S_(4)基纳米复合墨水,并结合直墨书写的3D打印技术合理设计了准固态MSCs的三维结构.得益于牢固锚定在还原氧化石墨烯(rGO)表面的NiCo_(2)S_(4)纳米颗粒和有序的三维微孔,锯齿状厚电极提供了丰富的反应位点并增强了离子传输.因此,三层锯齿状MSCs的面电容高达416.7 mF cm^(-2).在1 mA cm^(-2)的电流密度下,单层、双层和三层电极的锯齿状MSCs的面电容与相对应的网格状MSCs相比,分别增加了127.1%、349.8%和585.9%.本工作为高面电容MSCs的材料和电极结构的跨尺度设计提供了新见解,推动了MSCs在柔性便携式电子设备中的集成应用研究.

摘要：磁场触发的催化剂轨道电子自旋排列已成为促进析氧反应的一种有趣而可行的策略.然而,具有强d-d库仑相互作用的高熵合金(HEAs)催化剂中的磁场增强机制尚未得到充分挖掘.在此,我们设计了具有优异软磁性的高熵合金金属片,在微小磁场下表现出显著的磁场增强催化作用,其磁导率可作为评估磁场增强的描述因子.具体地,仅施加50 mT的磁场,(FeCoNi)_(82.5)Cr_(17.5)HEAs的过电位下降就超过了36mV@10 mA cm^(-2).此外,过电位的降低与HEA的磁导率呈线性关系.原位拉曼光谱与理论计算结果表明,施加磁场可显著提高自旋密度,改善催化剂的3d电子与*O自由基的2p轨道之间的自旋相互作用,从而有效降低速率决定步骤(*O→*OOH)的能量障碍,进而促进O-O的形成.

摘要：柔性可穿戴的紫外线探测器在个体紫外线暴露监测、智能仿生眼和军事领域受到广泛关注.然而,传统不可拉伸的材料和器件结构设计限制了设备在可动态变形的人体皮肤和非平面表面上的精确监测应用和稳定附着.在本研究中,我们提出了基于氧化铜/碳-水凝胶-氧化锌/碳的新型应变隔离异质结构的本征可拉伸(拉伸应变或弯曲高达150%)紫外线探测器,该探测器具有高灵敏度(开/关比为2100%)、高稳定性(大于4000次循环),以及快速响应和恢复时间(分别为1.5和4 s).值得注意的是,该探测器通过水凝胶桥在氧化铜/碳和氧化锌/碳电极之间引入的p-n结能带结构,以及离子导电水凝胶中I^(-)/I_(3)^(-)的电化学反应机制,显著提高了其载流子效率和紫外线响应强度.本文通过集成传感器与所设计的电路板,进一步开发了一种无线紫外线报警系统,用于紫外线强度超标警报.此外,本文还设计了一种光电传感器阵列,并将其用作视网膜假体,以实现对环境紫外线强度的实时监测和成像.本文基于水凝胶基异质结构为开发可穿戴、可拉伸的光电紫外线传感器单元和成像阵列提供了一种新的可行方法.

摘要：Cobalt nanoparticles(NPs)catalysts are extensively used in heterogeneous catalytic reactions,and the addition of alkali metal promoters is a common method to modulate the catalytic performance because the catalyst's surface structures and morphologies are sensitive to the addition of ***,the underlying modulation trend remains ***,the adsorption of alkali metal promoters(Na and K)on the surfaces of face-centered-cubic(FCC)and hexagonal-closest packed(HCP)polymorphous cobalt was systematically investigated using density functional ***,the effect of alkali promoters on surface energies and nanoparticle morphologies was revealed on the basis of Wulff *** FCC-Co,the exposed area of the(111)facet in the nanoparticle increases with the adsorption coverage of alkali metal ***,the(311),(110),and(100)facets would disappear under the higher adsorption coverage of alkali *** HCPCo,the Wulff morphology is dominated by the(0001)and(1011)facets and is independent of the alkali metal adsorption *** work provides insights into morphology modulation by alkali metal promoters for the rational design and synthesis of cobalt-based nanomaterials with desired facets and morphologies.