摘要：以CaCO3(99.9%)、Li2CO3(99.9%)、Na2CO3(99.9%)K2CO3(99.9%)、H3BO3(99.9%)、Sm2O3(99.9%)为原料,按所设计的化学计量比称取以上原料,在玛瑙研钵中混合均匀并充分研磨,装入刚玉坩埚,采用固相法制备LiCaBO3:Sm3+材料;通过美国XRD6000型X射线衍射仪和日本岛津RF-540荧光分光光度计对材料的性能进行表征,所有测量均在室温条件下进行。LiCaBO3:Sm3+材料的发射光谱由三个橙红色发射峰组成,主峰位于561,602,651nm,分别对应Sm3+的4G5/2→6H5/2、4G5/2→6H7/2和4G5/2→6H9/2跃迁;监测602nm发射峰,得到其激发光谱由320～420nm的宽激发带组成。由激发和发射光谱看出,LiCaBO3:Sm3+能够有效地被紫外LED芯片激发,发射红色光。研究了Sm3+浓度(x)对LiCa1-xBO3:xSm3+材料发射强度的影响,结果表明:随Sm3+浓度的增大,发射强度先增强后减弱,Sm3+掺杂摩尔分数为3%时,发射强度最大,依据Dexter理论,计算得出其浓度猝灭机理为电偶极-偶极相互作用。掺入电荷补偿剂Li+、Na+和K+均提高了LiCaBO3:Sm3+材料的发射强度。

摘要：Chemodynamic therapy(CDT)is an emerging and promising strategy based on the Fenton or Fenton-like reaction in tumors[1–3].The tumor microenvironment(TME)has the characteristics of low acidity and overexpression of H2O2[4,5],thus providing favorable conditions for initiating the Fenton or Fenton-like *** CDT,intratumoral H2O2 is decomposed into highly toxic hydroxyl radicals(·OH)through the Fenton or Fenton-like reaction catalyzed by a metal-based nanocatalyst,which will cause irreversible damage to DNA,lipids,and proteins[6,7].

摘要：In order to analyze the lubricating characteristics at different meshing points in the cycloid pin wheel transmission process,the cycloid gear teeth were discretized,combined with the kinematic analysis of the cycloid pin gear transmission and the contact analysis of the gear *** progressive mesh densification method(PMD)was used to numerically solve the film *** influence of the design parameters and process parameters on the lubrication characteristics was *** elastohydrodynamic lubrication and mixed lubrication characteristics at different contact points were *** optimal meshing area of the cycloid gear tooth was determined,and the film thickness ratio,contact load ratio,maximum contact pressure at different points,average film thickness and roughness after contact deformation were *** conclusion of this study provides effective guidance for the research on the modification of cycloid gear teeth.

摘要：氮掺杂γ-石墨二炔(N-GDY)因其在能源、电子元器件和催化领域具有重要应用前景而备受关注.研究表明,N-GDY在不同的氮掺杂情况下会表现出迥异的物理化学性质.由于氮掺杂的多样性,N-GDY的理论及应用研究受到了极大的限制.鉴于此,本文采用鄂维南等人提出的DeepMD方法训练得到了具有第一性原理精度、适用于N-GDY的机器学习势.利用该机器学习势,系统研究了氮掺杂模式对N-GDY力学性能的影响.研究发现,氮原子掺杂会导致N-GDY的抗拉强度降低.在单个碳链上掺杂氮原子时,N-GDY的抗拉强度随着氮原子掺杂位点到苯环的距离变小而减弱.相邻碳链氮原子共掺杂能够使N-GDY表现出更强的各向异性力学特征.本文研究结果对N-GDY在能源存储和柔性设备等领域的潜在应用提供了理论支持,同时也表明了机器学习势在从大规模数据集中学习并预测碳纳米材料复杂力学性质方面的潜力,为纳米材料设计及工程应用具有重要指导作用.

摘要：非晶合金是非晶材料家族中的新成员,由于缺乏原子排列长程有序特征,具有独特的性能和广泛应用前景.然而,非晶合金的形成、成分设计和形变问题在该领域长期未得到解决,制约着新型非晶合金的高效开发.传统上,多组元非晶合金的成分设计主要遵循相图研究范式,以温度调控为出发点,确定低液相线的成分为落脚点,尤其强调深共晶成分.然而,对于缺乏相图的多组元体系则力所不及,亟需新的理论突破.本文综述了非晶转变中的热力学与动力学基本规律,重点探讨了热力学与动力学性质之间的关联性,尤其是梳理了材料熔化熵与熔点粘度、熔点等多个非晶形成经典参量之间的内在关联,提出并论证了熔化熵和振动熵为非晶形成的关键热力学参量,可有效指导高性能非晶合金的设计和表征.结合实际应用中对非晶材料的工程要求,讨论了化学成分调控对非晶合金剪切带的萌生密度和扩展稳定性的影响,并总结了在单调加载和疲劳加载条件下剪切带行为对非晶合金断裂过程的作用.最后展望了振动熵和构型熵之间争议问题,提出未来工作中需要发展具有物理意义玻璃形成能力指标和可靠数据库的需求,混合加载模式下的韧性以及疲劳和韧性之间的权衡等问题.本文为进一步建立高性能非晶材料成分设计路径提供了参考与指导.

摘要：基于表面等离子激元自发辐射放大噪声系数理论,研究了长程表面等离子激元噪声系数变化规律,设计了嵌有金属条的长程表面等离子结构.数值模拟得到表面等离子及周期条状长程表面等离子的噪声系数变化规律.给出入射波长从0.5μm到1.75μm,每隔0.25μm的噪声特性,发现随着波长的增加噪声系数趋近于常数.仿真结果表明:表面等离子及长程表面等离子自发辐射放大的噪声系数随着增益介质增大而明显增强;周期条状长程表面等离子结构中,随着金属膜厚度以及金属条高度及个数增加导致噪声系数增加,其中金属膜厚度对于其作用较明显.

摘要：直接乙醇燃料电池的效率与阳极乙醇氧化反应(EOR)C1路径选择性密切相关,然而C-C键断裂的能垒较高,使得C1路径产物选择性低,从而限制了直接乙醇燃料电池效率的提升.设计具有高C-C裂解效率的电催化剂,对于构建高效直接乙醇燃料电池具有重要意义.本文报道了一种Mott-Schottky异质结调节催化活性中心电子状态从而促进EOR过程中C-C裂解的新策略.我们以PdAu合金纳米颗粒(NPs)为模型催化剂,制备了PdAu@N_(x)C金属-碳Mott-Schottky异质结构.PdAu NPs(15.9±1.9 nm)均匀地分散在N掺杂的碳载体上.我们通过在宽范围内调节N掺杂量,调控异质结界面电势,形成了不同程度的电荷分离.通过催化剂结构与性能研究,建立了反应活性与催化剂功函数之间的线性关系,表明金属/碳界面电子转移可以有效促进EOR.优化的催化剂PdAu@N10.69C,显示出高C1产物选择性(FE=51.1%),质量活性(MA=9.7 A mg Pd^(-1))和比活性(SA=13.2 mA cm^(-2)),优于PdAu@C和大多数报道的Pd基EOR催化剂.实验结果和理论计算表明,N的引入促进了电子由碳层向PdAu转移,加强了对*CH_(3)CO的吸附,从而提高了C-C键的断裂效率.这项工作为整流策略提高EOR性能提供了一种新的研究思路.

摘要：In this paper, we explore the analysis and design of wireless networked control system (WNCS) utilizing adaptive coded modulation (ACM) schemes, which can improve the energy efficiency and increase data rate over a fading channel. To capture the characteristics of varying rate, interference, and routing in wireless transmission channel, we introduce the concept of equivalent delay (ED). Based on the time-varying network condition, the analytic lower and upper bounds of EDs are given. Whereafter, WNCS is modelled as a discrete-time system with time-varying input delay. Sufficient stabilization condition of the closed-loop WNCS is derived by making use of novel techniques of time-delay system. Finally, the numerical result shows the validity of our proposed control strategies.

摘要：Flexible sensors that can respond to multiple mechanical excitation modes and have high sensitivity are of great significance in the fields of electronic skin and health *** multiple signal responses to skin such as strain and temperature remains an important ***,new multifunctional ion-crosslinked hydrogels with toughness and conductivity were designed and prepared in this work.A chemical gel with high mechanical strength was prepared by cross-linking acrylamide with N,N’-methylenebisacrylamide and ammonium *** addition,in order to enhance the conductive properties of the hydrogel,Ca^(2+),Mg^(2+)and Al^(3+)ions were added to the hydrogel during *** double-layer network makes this ionic hydrogel show excellent mechanical ***,the composite hydrogel containing Ca^(2+)can reach a maximum stretch of 1100%and exhibits ultra-high sensitivity(Sp=10.690 MPa^(-1)).The obtained hydrogels can successfully prepare wearable strain sensors,as well as track and monitor human *** present prepared multifunctional hydrogels are expected to be further expanded to intelligent health sensor materials.

摘要：基于反步技术,对带有不确定非线性项和不确定非线性系数的随机非完整链式系统,设计了自适应状态反馈镇定器.给出了能够保证系统依概率几乎渐近稳定到平衡点的切换控制.最后用仿真验证了控制器的有效性.