摘要：As the deployment,supporting,and stability mechanisms of satellite antennas,space-deployable mechanisms play a key role in the field of *** order to design truss deployable antenna supporting mechanisms with large folding rate,high accuracy,easy deployment and strong stability,aiming at the geometric division of the parabolic reflector,a novel method based on symmetric hexagonal division and its corresponding modular truss deployable antenna mechanism is proposed,and the original method based on asymmetric triangular division and its corresponding mechanisms are presented for comparative ***,the screw theory is employed to analyze the mobility of different ***,the improved three-dimensional mesh method is used to divide the reflector surface of a large parabolic antenna designed by the two different methods,and the profile accuracy and the type of links are taken as the evaluation indexes to quantitatively analyze the division ***,a three-dimensional model of the modular deployable mechanism based on the symmetric hexagonal design is developed,and the deployable mechanisms with different configurations based on the two design methods are compared and analyzed from the mechanical *** research results provide a good theoretical reference for the design of deployable truss antenna mechanisms and their application in the aerospace field.

摘要：Space deployable structures with large calibers, high accuracy, and large folding ratios are indispensable equipment in the aerospace field. Given that the single-DOF 3 RR-3 RRR deployable unit cannot be fully folded, this study proposes a 3 UU-3 URU deployable unit with two kinds of DOF: folding movement and orientation adjustment. First, based on the G-K formula, the DOF of the 3 UU-3 URU unit is analyzed. Then, the 3 UU-3 URU unit is used to construct a deployable truss antenna with a curved surface, and the DOF of the whole deployable antenna containing multiple 3 UU-3 URU units is calculated. The structural design of a deployable antenna with two loops is carried out with specific parameters and geometric relations. Next, a DOF simulation of a basic combination unit composed of three 3 UU-3 URU units is performed. Finally, a prototype of the basic combination unit is manufactured, and the DOF of the mechanism is experimentally verified.

摘要：The anchoring property of the substrate surface of liquid crystal cells plays an important role in display and nondisplay fields. This property directly affects the deformation of liquid crystal molecules to change the phase difference through liquid crystal cells. In this paper, a test method based on the alternating-current bridge is proposed to determine the capacitance of liquid crystal cells and thus measure the anchoring energy of the substrate surface. The anchoring energy can be obtained by comparing the capacitance-voltage curves of twisted nematic liquid crystal cells with different anchoring properties in experimental and theoretical results simulated on the basis of Frank elastic theory. Compared with the other methods to determine the anchoring energy, our proposed method requires a simple treatment of liquid crystal cells and allows easy and high-accuracy measurements, thereby expanding the test ideas on the performance parameters of liquid crystal devices.

摘要：In the recent times sodium ion batteries(SIBs)have come to the forefront as an economic and resourceful alternative to lithium-ion batteries(LIBs)for powering portable electronic devices and large-scale grid *** the specific capacity,energy density and long cycle life of batteries depend upon the performance of anode materials;their quest is the ultimate need of the *** the anode materials,the semimetallic pnictogens(As,Sb,Bi)and their compounds offer high gravimetric/volumetric capacities,but suffer from undesired volume expansion and inferior electrical ***,this paper reviews the recent progress in semimetallic pnictogens as alloying anodes and their compounds mainly as conversion-alloying *** debatable sodiation mechanisms(intercalation or alloying)have been presented with emphasis on in situ/ex situ advanced characterization methods well supported by theoretical modeling and *** reviewed electrochemical reaction mechanisms,coherent structural designs and engineering provide a vital understanding of the electrochemical processes of Na^(+) ion *** existing challenges and perspectives are also presented,and several research directions are proposed from the aspects of special morphological design,employing conductive substrates,electrolyte additives and reducing particle size for technical and commercial success of SIBs.

摘要：As epoxy functional group has high anticancer activity, α, β-epoxyketones were designed and synthesized as new anticancer agents, and their structures were confirmed by UV, 1H NMR, IR, MS technigeces and elemental analysis. Their in vitro anticancer activities were evaluated by MTF method and the results showed that the compound 4c exhibited good activity with IC50 of 17.8, 22.0 and 24.1 μg/mL against A-549, Hela and HepG2 cells, respectively. The dose of LD50 of the mice by intragastric administration was 1864.4 mg/kg. Therefore, the α, β-epoxyketones could potentially provide as new anticancer agents.

摘要：TiO_(2)-based materials have been considered as one of most promising alternatives for high-performance Li(Na)-ion batteries because of the low cost,simple composition,easy synthesis,good environmental protection,excellent safety and relatively high specific ***,the inferior electronic conductivity and poor ion diffusion coefficients are the biggest bottlenecks that restrict the popular *** effort has been focused on resolving these problems toward large-scale applications,and numerous significant advances have been *** the present work,a comprehensive overview of structure characteristics,electrochemical reaction mechanism and modification strategies of TiO_(2)-based materials was *** recent advances of various efficient ways for improving conductivity,Li(Na)storage capacity,rate capability and cycle stability are systematically summarized,including surface engineering,constructing composite and element doping,*** TiO_(2)-based materials with novel porous heterogeneous core-shell structures have been regarded as one of the most effective ways to resolve these ***,the future research directions and development prospects of TiO_(2)-based anode materials used in the manufacture of high-performance Li(Na)-ion batteries are *** review can provide important comprehension for the construction and optimization of highperformance of TiO_(2)-based anode materials.

摘要：The martensitic transformation,mechanical,and magnetic properties of the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) (x=0.125,0.25,0.375,0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5)[(x=0.125,y=0.125,0.25,0.375,0.5) and (x=0.125,0.25,0.375,y=0.625)]alloys were systematically studied by the first-principles *** the formation energy,the martensite is smaller than the austenite,the Ni–(Co)–Mn–Cu–Ti alloys studied in this work can undergo martensitic *** austenite and non-modulated (NM) martensite always present antiferromagnetic state in the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) (y<0.625) *** y=0.625 in the Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) series,the austenite presents ferromagnetic state while the NM martensite shows antiferromagnetic *** doping can decrease the thermal hysteresis and anisotropy of the Ni–(Co)–Mn–Ti *** Mn and decreasing Ti content can improve the shear resistance and normal stress resistance,but reduce the toughness in the Ni–Mn–Cu–Ti *** the ductility of the Co–Cu co-doping alloy is inferior to that of the Ni–Mn–Cu–Ti and Ni–Co–Mn–Ti *** electronic density of states was studied to reveal the essence of the mechanical and magnetic properties.

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：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.