摘要：本工作利用基于密度泛函理论的高通量计算方法,研究了由金属团簇和四羟基苯(THB)分子形成的232个具有Kagome晶格的有机金属网格.在由THB分子和过渡金属原子三聚体(称为Y_(3)-THB)组成的有机金属网格中,有7种网格结构是本征有机拓扑绝缘体.进一步引入过渡金属原子(Tl,Pb,Bi)后得到的X_(3)Y_(4)-THB结构中,发现了9个具有较大自旋轨道耦合能隙的本征有机拓扑绝缘体.在这些本征拓扑绝缘体中,α相Pb_(3)Zn_(4)-THB结构是具有拓扑平带的拓扑绝缘体,其非平庸自旋轨道耦合能隙(97.5 meV)几乎是其平带带宽(22.5 meV)的4倍,是实现分数量子霍尔效应的理想平台.该工作为设计具有大能隙的二维有机拓扑绝缘体提供了新的途径.

摘要：Monitoring the electrophysiology activity of neurons and blood calcium signals can enable a better understanding of disease-related neural system ***,currently,in situ calcium ion monitoring tools are scarce and exhibit low integration and limited *** this letter,we propose an implantable probe with an integrated in situ Ag/AgCl reference electrode(ISA/ARE)that can monitor action potential(AP)and Ca^(2+) concentrations.

摘要：Significant aerodynamic engine instability can occur during the operation of marine gas turbines as airflow enters the compressor through a 90°turning and causes inlet *** study adopts the method of simulating board equivalence to provide the target distortion flow field for ship *** characteristics of the flow field behind the simulated board are obtained through experiments and numerical simulations,through which the relationship between the height of the simulated board and the total pressure distortion is ***,the study summarizes the prediction formula to achieve a distortion prediction of 0.8%–7.8%.In addition,this work analyzes the effects of drilling methods and diameters on flow nonuniformity by drilling holes into the simulation *** results indicate that drilling holes on the board can weaken the nonuniformity of the flow field within a certain range and change the distribution pattern of total pressure in the ***,the total pressure distortion no longer changes significantly when the number of holes is too *** proposed double simulation board structure is capable of obtaining the following two types of distorted flow fields:symmetrical dual lowpressure zones and low-pressure zones with high distortion intensity at the compressor *** distortion equivalent simulation method proposed in this work can obtain various types of distortion spectra,thereby meeting the distortion parameter requirements for the antidistortion testing of marine engines.

摘要：为满足直升机传动系统对复杂工况下齿轮轻量化设计的迫切需求,提出了一种高功率密度斜向支柱锥齿轮辐板结构的设计优化方法。基于考虑应力约束的变密度法,对锥齿轮辐板进行了拓扑优化与重构,得到一种新颖的突破传统构型的高功率密度斜向支柱锥齿轮辐板结构。在传统粒子群优化(Particle swarm optimization,PSO)算法的基础上,引入马尔可夫链和进化因子,自适应地选择跳变策略和延迟信息,进而发展了智能先进的时滞跳变粒子群优化(Switching delayed PSO,SDPSO)算法,并将其应用于斜向支柱锥齿轮辐板结构的尺寸优化。优化后,锥齿轮辐板质量共减小了19.24%,所有工况的最大von Mises应力共减小了7.27%,各工况应力分布更加均匀,证明了所设计的锥齿轮辐板的结构优势和所提出的设计优化方法的先进性。

摘要：四环素是一种广泛使用的抗生素,但它在环境中难以降解,而且会促使耐药细菌的出现.因此,迫切需要采取有效的措施对其进行检测和分解.在此背景下,我们设计了一种多肉状的ZnO/MOF/Fe_(3)O_(4)混合微型马达,用于动态检测和光催化降解四环素.我们使用微纳米加工和种子生长方法成功制备了具有多肉植物状结构的ZnO微型马达.在氧化锌马达阵列上,通过表面修饰,比如改变其表面电位、负载响应性检测功能MOF、磁性纳米颗粒和催化剂,最终得到了可用于动态荧光检测和高效降解的自驱动可控微马达.这种功能性微马达在环境检测和治理等方面具有很好发展前景.

摘要：非质子锂氧电池基于锂金属与氧的可逆反应生成Li_(2)O_(2),可提供极高的理论能量密度.然而,Li_(2)O_(2)的成核/消除机制仍然不清楚.因此,构建能在原子水平上深入了解催化机理的催化剂体系,是开发高性能锂氧电池的关键.在此,我们报道了一种在富氧空位的Co_(3)O_(4)(Pd1-Co_(3)O_(4x))中实现Pd单原子选择性锚定的策略.原子水平表征技术揭示了Pd原子优先地结合到缺陷Co_(3)O_(4)的四面体位点.理论计算表明,选择性锚定的Pd单原子与氧空位的耦合引起了明显的电荷重分布,这可以有效地提高Pd 4d轨道在费米能级附近的能带占用率,促进电子转移,有利于中间体的吸附.这种双重相互作用不仅可以调节放电过程中Li_(2)O_(2)的成核生长过程,而且有利于Li_(2)O_(2)上的电子云的离域,减弱Li-O键的强度,从而促进Li_(2)O_(2)在充电过程中的分解.本研究对锂氧电池在原子水平上的催化机理和高效催化剂的合理设计提出了一些见解.

摘要：In vaccine development,broadly or cross-type neutralizing antibodies(bnAbs or cnAbs)are frequently targeted to enhance *** immunodominant antibodies could help fine-tune vaccine immunogenicity and augment the precision of immunization ***,the methodologies to capitalize on the attributes of bnAbs in vaccine design have not been clearly *** this study,we discovered a cross-type neutralizing monoclonal antibody,13H5,against human papillomavirus 6(HPV6)and *** nAb exhibited a marked preference for HPV6,demonstrating superior binding activity to virus-like particles(VLPs)and significantly higher prevalence in anti-HPV6 human serum as compared to HPV11 antiserum(90%vs.31%).Through co-crystal structural analysis of the HPV6 L1 pentamer:13H5 complex,we delineated the epitope as spanning four segments of amino acids(Phe42-Ala47,Gly172-Asp173,Glu255-Val275,and Val337-Tyr351)on the L1 surface *** interaction analysis and site-directed mutagenesis revealed that the Ser341 residue in the HPV6 HI loop plays a critical role in the interaction between 13H5 and *** Ser341 with alanine,which is the residue type present in HPV11 L1,almost completely abolished binding activity to *** swapping amino acids in the HPV11 HI loop with corresponding residues in HPV6 L1(Ser341,Thr338,and Thr339),we engineered chimeric HPV11-6HI ***,the chimeric HPV11-6HI VLPs shifted the high immunodominance of 13H5 from HPV6 to the engineered VLPs and yielded comparable neutralization titers for both HPV6 and HPV11 in mice and non-human *** approach paves the way for the design of broadly protective vaccines from antibodies within the main immunization reservoir.

摘要：生物材料表面的物理性质,如拓扑结构,由于其易于加工和稳定的生物作用而受到广泛关注.虽然已有许多研究报道了材料表面拓扑结构与细胞的相互作用,但由于不同研究中使用的微结构和实验环境的多样性,生物材料表面不同微结构与细胞/组织行为之间的影响关系尚未得到很好的统一评价.在本研究中,我们设计了11种图案(三角形、矩形、圆形等),这些图案包含两种类型的形貌(微坑和微柱),这样一共得到22种表面拓扑结构.我们在体外和体内对这些微结构影响细胞和组织的生物作用进行了评估.我们的研究结果表明,由连续微坑形成的凹槽微结构促进细胞迁移效果相比其他微结构更强.其中,由三角形微坑组成的凹槽在体外对细胞迁移的促进作用最强.在大鼠皮下模型中,这种三角形微坑组成的凹槽结构减少了纤维组织的包封,促进了血管的形成.

摘要：由可见光驱动的将CO_(2)转化为高附加值燃料是一种清洁可再生的技术,有助于控制全球变暖和应对能源短缺.近年来,二维的金属偶氮盐框架(2D MAFs)因其特定的电子传输路径、高度暴露的表面活性位点及可调节的吸光能力,在CO_(2)光还原研究中备受关注.然而,对其在该领域的研究仍处于初级阶段.本文设计了一种新型二维MAFs(compound 1),通过四-(4-四唑基苯基)乙烯(H;4;TTPE)与钴的自组装实现了对CO_(2)的光还原.作为对比,通过类似的合成过程构建了具有三维结构的compound 2.非均相光催化实验结果显示,2D compound 1的光还原性能明显优于3D compound 2,在相同条件下,其CO产率高达11.56 mmol g^(-1)h^(-1),是compound 2(1.94 mmol g^(-1)h^(-1))的6倍.这一性能优势源于compound 1独特的二维结构,其不仅具有有利于CO_(2)还原的能级,还能在整个CO_(2)光还原过程中促进电子-空穴高效分离.本工作为设计适用于高效CO_(2)光还原的2D MAFs光催化剂指引了方向.

摘要：电催化二氧化碳还原反应(CO_(2)RR)能够利用可再生电能将CO_(2)转化为高附加值化学品和燃料,是一项有望缓解当下环境挑战的技术方案.本文总结了CO_(2)RR稳足性下降的根本原因,并探讨了解决这一问题的有效策略以及最新的研究进展.首先,在外加电位的作用下,催化剂会发生结构转变,且碳沉积或气体杂质引起的催化剂中毒都会降低CO_(2)RR的稳定性.其次,气体扩散层(GDL)附近发生水淹和盐沉淀会阻碍反应物/生成物的传输,三相界面会受到破坏.在长时间服役时,液压和电流的作用会导致GDL开裂.在电解质方面,碱性电解质会与CO_(2)中和,形成碳酸盐沉淀;而酸性介质腐蚀催化剂,并伴随严重的析氢副反应.另外,电解质中的金属离子杂质的优先还原进一步加剧了稳定性的衰减.深入理解CO_(2)RR中各类失活现象对设计稳定、高效的CO_(2)电催化系统具有指导意义.针对CO_(2)RR稳定性研究目前所面临的困境,本文最后展望了该领域未来的研究方向.