摘要：本文针对一类具有时变输出约束链式非完整系统的预设时间镇定问题,首先通过tan型障碍Lyapunov函数处理系统输出约束,然后基于所给的新型切换时变函数,直接应用于虚拟(实际)控制器设计,提出了系统状态反馈镇定的非缩放变换设计方案.本文所设计的控制器使得闭环系统状态不违反约束的同时,可在任意给定的有限时间内收敛到零点.与传统的基于缩放变换设计相比,本文所提出的控制策略既有效解决了控制器的计算奇异性问题,又减少了关于时变缩放函数的计算,使控制器设计更为简单.最后,通过仿真结果验证了所提设方法的有效性.

摘要：Metabolites play important roles in numerous cell biology processes,such as cell proliferation,differentiation,stress response,and cell death[1].Recently,lactate and lactate-derived lysine residue lactylation(Kla)have emerged as newly discovered epigenetic modifications that play critical roles in various physiological and pathological *** the history of lactate research,we can categorize the studies into three mile stones(Fig.S1 online).

摘要：Prosthesis implantation and fat transplantation are common breast *** general,prosthesis implantation alone does not achieve a realistic enough appearance,and fat transplantation alone is difficult to achieve in the correct *** date,no reports have focused on methods of combining fat with implanted prostheses for breast *** a newly designed bionic ink(i.e.,polyether F127 diacrylate(F127DA)&poly(ethylene glycol)diacrylate(PEGDA))and projection-based three-dimensional bioprinting(PBP),we report the development of a new method for printing porous *** was used to improve the printing precision of the prosthesis by increasing the gel point of F127DA and reducing the impact of external *** compression modulus of the printed prosthesis was very close to that of prostheses currently used in clinical practice and to that of natural ***,stromal vascular fraction gel(SVF-gel),a human fat extract,was injected into the pores of the synthesized prostheses to prepare a prosthesis mixed with adipose *** were implanted subcutaneously in nude mice to observe their biological *** 14 and 28 days of observation,the prosthesis showed good biocompatibility,and adipose tissues grew well in and around the *** result shows that a porous prosthesis containing pre-placed adipose tissues is a promising breast reconstruction material.

摘要：区别于在三维拓扑绝缘体引入磁性的设计思路,在二维铁磁材料中引入拓扑特性是实现量子反常霍尔效应(QAHE)的一种新途径.最近实验成功制备的二维铁磁绝缘体为实现该效应提供了新的契机.本文基于密度泛函理论的第一性原理计算,设计了一个在过渡金属三元硫属化合物Cr2A2X6(其中A=Si,Ge,Sn;X=S,Se,Te)中实现QAHE的普适规则.该设计原则是,通过适当的表面修饰可将二维非拓扑的磁性绝缘体转变为量子反常霍尔体系.以硅烯修饰的Cr2Sn2Se6(Si/Cr2Sn2Se6)为例,计算发现Cr2Sn2Se6单层的居里温度可提高至92 K.具体的电子能带和拓扑性质计算发现,Si/Cr2Sn2Se6异质结存在约30 meV的拓扑非平庸带隙,即该体系中可以实现QAHE.进一步的低能有效模型分析表明,Si/Cr2Sn2Se6的拓扑特性是由Cr2A2X6六角晶格中的Cr原子贡献的.此外,还发现其他Cr2A2X6通过表面修饰也可以实现QAHE.以上研究结果证实了本文方案的普适性,其为实现高温QAHE提供了新的理论指导.

摘要：本文提出了一种通过静电学中电荷分布场来求解电动力学中含源介质传播场的新方法,定义了变换光学中的一种拓扑不变量——环绕数,并且发现一种新的幻象效应.变换前后不同分布的光源保持环绕数不变。电磁场在远场永远保持相似性,从而实现对光源幻象的准确调控,实现光学“高斯定理”.文中主要列举了多个多光源幻象透镜,通过精确计算发现,电磁场的等相位面与静电场等势面保持一致,且坡印廷矢量与电场线保持一致,此时得到的传播电磁场可根据静电场来分析其特性,光源可被视为相对等量的静电荷.由此实现的多光源不干涉幻象,远场看起来就像是一个大光源形成的电磁场.该工作为利用简单静电场设计光学器件提供了新思路,在变换光学中提出了以更本质的拓扑不变量来研究光学现象,在天线设计、大功率照明系统构造和军事伪装制造等方面具备潜在的应用价值.

摘要：水凝胶作为承载组织的替代产品引起了广泛关注.然而,与能够通过有限的变形来承受复杂载荷的承载组织不同,传统的水凝胶由于其柔软的特性,无法在低应变状态下表现出刚性响应.基于承载组织的软硬组分之间的协同作用,我们设计了采用软基质(正泊松比)和硬框架(负泊松比)的复合水凝胶,其刚度分别比基质和框架高18.9和4.2倍.相反,结合软基质(正泊松比)和框架(正泊松比)的设计对刚度增强有限.通过有限元分析,揭示了软基质与框架之间正、负泊松比斥力作用的内在机理.本研究为今后设计基于软硬组分协同效应的复合水凝胶提供了思路.

摘要：光阳极内部严重的体相复合和缓慢的析氧反应(OER)动力学严重限制了光电化学(PEC)水分解器件的应用.为解决这2个问题,本文对原子层沉积修饰的SnS纳米片阵列进行空气退火处理,实现了晶面取向的调控并获得了具有高质量光阳极/助催化剂界面的复合光阳极器件.基于实验观测和理论计算分析,SnS中(001)晶面的降低减少了光生载流子的体相复合,提高了载流子的体相分离能力.此外,形成的ZnTiOS薄膜作为高效的助催化剂降低了表面OER反应势垒,减少了界面复合,延长了载流子寿命.这些协同效应显著增强了SnS的PEC性能,在1.23 V ***下得到1.97 mA cm^(-2)的光电流密度,起始电位达到0.21 V ***.该工作不仅提供了一种简便有效的策略,可以同时减少光阳极中的体相和表面复合,也为通过后处理或非原位策略制备高效助催化剂提供了新思路.

摘要：工业有机污染物具有多相态共存、治理工艺复杂、治理成本高等特点.因此针对有机污染物的临氧裂解/催化氧化治理工艺,研究了一种基于改进的NSGA–Ⅱ的优化控制方法.首先,根据治理过程的工艺要求和设备操作参数,使用Aspen Plus建立了稳态模拟系统,并对关键控制参数进行了灵敏度分析.然后以最低的总能耗和最大的废水治理量为优化目标,使用改进的NSGA–Ⅱ优化处理过程的控制参数,获得一组帕累托最优解.最后,基于能量平衡设计了厂级有机污染物综合处理的能量自平衡控制方案,并进行动态模拟和实验装置测试.模拟和实验结果表明,该系统具有良好的动态响应性能,所设计的实验装置稳定运行状态下能耗低,净化效率高.

摘要：The site-specific incorporation of the noncanonical amino acid(ncAA)into proteins via genetic code expansion(GCE)has enabled the development of new and powerful ways to learn,regulate,and evolve biological functions in ***,cellular biosynthesis of ncAA-containing proteins with high efficiency and fidelity is a formidable *** this review,we summarize up-to-date progress towards improving the efficiency and orthogonality of GCE and enhancing intracellular compatibility of introduced translation machinery in the living cells by creation and optimization of orthogonal translation components,constructing genomically recoded organism(GRO),utilization of unnatural base pairs(UBP)and quadruplet codons(four-base codons),and spatial separation of orthogonal translation.

摘要：The key to managing fracture is to achieve stable internal fixation,and currently,biologically and mechanically appropriate internal fixation devices are urgently *** excellent biocompatibility and corrosion resistance,titanium–niobium alloys have the potential to become a new generation of internal fixation materials for ***,the role and mechanism of titanium–niobium alloys on promoting fracture healing are still ***,in this study,we systematically evaluated the bone-enabling properties of Ti45Nb via in vivo and in vitro *** vitro,we found that Ti45Nb has an excellent ability to promote MC3T3-E1 cell adhesion and proliferation without obvious *** phosphatase(ALP)activity and alizarin red staining and semiquantitative analysis showed that Ti45Nb enhanced the osteogenic differentiation of MC3T3-E1 cells compared to the Ti6Al4V *** the polymerase chain reaction experiment,the expression of osteogenic genes in the Ti45Nb group,such as ALP,osteopontin(OPN),osteocalcin(OCN),type 1 collagen(Col-1)and runt-related transcription factor-2(Runx2),was significantly higher than that in the control ***,in the western blot experiment,the expression of osteogenic-related proteins in the Ti45Nb group was significantly increased,and the expression of PI3K–Akt-related proteins was also higher,which indicated that Ti45Nb might promote fracture healing by activating the PI3K–Akt signaling *** vivo,we found that Ti45Nb implants accelerated fracture healing compared to Ti6Al4V,and the biosafety of Ti45Nb was confirmed by histological ***,immunohistochemical staining confirmed that Ti45Nb may promote osteogenesis by upregulating the PI3K/Akt signaling *** study demonstrated that Ti45Nb exerts an excellent ability to promote fracture healing as well as enhance osteoblast differentiation by activating the PI3K/Akt signaling pathway,and its good biosafety has been confirmed