Recent advances in non-toxic quantum dots and their biomedical applications

Quantum dots (QDs) with unique quantum confinement effect and electro-optical properties are attractive for biomedical applications. Toxic effects of traditional semiconductor QDs made of heavy metal ions have serious safety concerns for their undesired environmental or healthy impact. Recent reports on core-shell structure modification of QDs by using biocompatible ligands or polymers is one way to be effectively minimizing toxicity effects of traditional QDs. Furthermore, designs of heave metal-free and metal-free QDs formulations are more promising alternatives, due to the non-toxic and eco-friendly nature of the starting materials. In article, we will review the recent designs of non-toxic or less toxic QDs, including carbon-based, biomolecules-based, silicon-based, and ternary I-III-VI QDs, and their biological applications (bio-imaging, drug delivery, gene therapy and immunoassay).     

纳米稀土金属有机框架材料的合成及其生物医学应用研究进展

近年来,纳米稀土金属有机框架(MOF)材料的合成及其在生物医学,特别是在肿瘤诊断和治疗方面的应用研究引起了科学家们广泛的关注.一方面,纳米稀土MOF具有独特的光学和磁学性质,可用于生物成像(如荧光成像和磁共振成像等);另一方面,纳米稀土MOF的组成和结构多样,且具有高的比表面和大的孔容,是具有潜力的药物控释载体.这种集多种功能于一身的纳米稀土MOF为开发新型的诊疗一体化试剂提供了一个新的平台.介绍了近年来纳米稀土MOF的合成及其在生物医学方面的应用的研究进展.     

柔性可穿戴应力传感器的研究进展

柔性可穿戴传感器由于其可拉伸、可弯曲、轻薄便携和优异的电学性能等特点被广泛应用于健康诊断、运动监测、康复医疗、娱乐等领域.近年来,柔性可穿戴应力传感器取得了显著的进步,多种可测量健康信息的柔性应力传感器已被应用于脉搏波、运动、呼吸和心电图(electrocardiogram,ECG)检测.然而,柔性传感器的发展仍然有诸多待解决的问题.对近年柔性应力传感器的发展进行了全面的归纳总结,从应力传感器的工作原理、结构设计展开,探讨了如何构建高性能柔性应力传感器,讨论了当前柔性传感器存在的问题,展望了未来柔性应力传感器的发展趋势.出色的柔韧性、良好生物兼容性、快速响应、高灵敏度、多功能集成的柔性可穿戴传感器展现出广阔的应用前景.     

金属纳米团簇在电化学领域的应用研究进展

尺寸小于2nm的金属纳米团簇是由几个到几百个原子组成的纳米结构材料.对于金属纳米团簇,由于其大部分甚至所有金属原子可能暴露于表面而具有高的表面原子比例,该独特的原子堆积结构使其具有高的表面活性,因此其在催化反应中具有重要应用价值.同时,其明确的原子排列和堆积结构使其可作为模型催化剂,用于研究纳米结构-性能之间的关系.笔者简要总结了近年来金属纳米团簇的研究进展和现状,重点总结了其在电化学领域的应用,包括电催化和电化学传感,最后对其未来在电催化和电分析领域的应用前景进行了展望.     

氧化铈纳米粒子的制备及其生物应用进展

由于铈离子可以在Ce~(3+)和Ce~(4+)之间可逆转换,以及氧空位的存在,氧化铈(CeO_(2-x),x=0～0.5)纳米粒子具有优异的催化特性,作为一种用途广泛的稀土氧化物得到了广泛的关注.Ce原子能够快速而大幅度地调整其电子结构(如产生氧空位或缺陷),以最佳的结构适应其周围环境,具有多种酶类活性(包括超氧化物氧化酶、过氧化氢酶和氧化酶等),可以清除体内产生的各种毒性活性氧.氧化铈在生物分析、生物医学、药物传递和生物支架等生物领域展现出了良好的应用前景.综述了氧化铈的制备方法及其在生物领域的应用进展.     

HEVC码率控制技术的研究进展

鉴于码率控制在视频编码应用中的重要性,综述了针对新一代国际视频编码标准HEVC (high efficiency video coding)的码率控制技术研究进展。介绍了码率控制的基本工作原理,通过调节编码器参数使输出码率符合信道带宽限制或满足存储设备的容量需求,主要包含比特分配和比特控制2个部分。然后,介绍了HEVC开发过程中接收的2个重要码率控制技术提案,从码率模型和比特分配两方面阐述了提案中的URQ (unified rate-quantization) 模型码率控制算法和R-λ模型码率控制算法。依据比特控制中的码率模型选择,把近年出现的HEVC码率控制算法分为Q域或λ域方法,并分别展开论述和技术点归纳;对HEVC扩展及其相应的码率控制进行了简要阐述。最后,结合码率控制仍需解决的问题,提出一些值得进一步探索的工作。     

High plastic Zr-Cu-Fe-Al-Nb bulk metallic glasses for biomedical applications

Four Zr-Cu-Fe-Al-based bulk metallic glasses (BMGs) with Zr contents greater than 65at% and minor additions of Nb were designed and prepared. The glass forming abilities, thermal stabilities, mechanical properties, and corrosion resistance properties of the prepared BMGs were investigated. These BMGs exhibit moderate glass forming abilities along with superior fracture and yield strengths compared to previously reported Zr-Cu-Fe-Al BMGs. Specifically, the addition of Nb into this quaternary system remarkably increases the plastic strain to 27.5%, which is related to the high Poisson's ratio and low Young's and shear moduli. The Nb-bearing BMGs also exhibit a lower corrosion current density by about one order of magnitude and a wider passive region than 316L steel in phosphate buffer solution (PBS, pH 7.4). The combination of the optimized composition with high deformation ability, low Young's modulus, and excellent corrosion resistance properties indicates that this kind of BMG is promising for biomedical applications.     

MXenes基光催化剂制备的研究进展

二维材料因其载流子迁移和热量扩散都被限制在二维平面内,使得这种材料展现出许多奇特的性质而受到广泛关注.二维过渡金属碳化物、氮化物或碳氮化物 (MXenes) 是一种新型的二维层状结构材料,具有高电子传导率、较大的比表面积、较好的机械性能以及独特的层状结构,已被广泛应用于储能、催化、环境等领域.该文主要阐述了MXenes基光催化剂的不同制备策略并总结了不同制备过程中的优缺点.最后,对MXenes基光催化剂及其复合材料在新兴领域的未来发展和研究方向提出了独特的见解和展望.     

酞菁配合物的合成及在肿瘤诊断与治疗中的研究进展

由于酞菁(Pc)配合物具有大的共轭体系,在催化、光电转换以及生物医学领域均具有广泛的应用.Pc配合物的合成主要包括:插入配位合成方法、直接取代合成法、模板反应合成法.Pc配合物在肿瘤诊断与治疗领域的应用主要包括光声成像(PAI)、磁共振成像(MRI)、光动力治疗(PDT)以及光热治疗(PTT)等.综述了Pc配合物的合成和在肿瘤诊断与治疗领域的最新研究进展.     

Zr-xNb-4Sn alloys with low Young’s modulus and magnetic susceptibility for biomedical implants

The microstructure, mechanical and magnetic properties of Zr–x (8, 9, 10, wt.%)Nb–4Sn alloys were investigated to obtain novel Zr-based alloy with low Young’s modulus and magnetic susceptibility for biomedical implants. After homogenization annealing, hot forging and solution annealing, Zr–8Nb–4Sn, Zr–9Nb–4Sn and Zr–10Nb–4Sn alloys were composed of β+α″ phase, β+α″ phase, β+ω phase, respectively. The temperature at which the α" and ω phase were transformed into β phase during the heating process was about 200 ​°C, and the phase transformation temperature decreased with the increase of Nb element. Among all the Zr–x (x ​= ​8,9,10)Nb–4Sn(wt.%) alloys, Zr–9Nb–4Sn alloy had the lowest Young's modulus of 46.6 ​GPa and the low magnetic susceptibility of 1.294 ​× ​10⁻⁶ cm³g⁻¹, which has a good application prospect for biomedical applications.     

Preparation, microstructure and degradation performance of biomedical magnesium alloy fine wires

With the development of new biodegradable Mg alloy implant devices, the potential applications of biomedical Mg alloy fine wires are realized and explored gradually. In this study, we prepared three kinds of Mg alloy fine wires containing 4 wt% RE(Gd/Y/Nd) and 0.4 wt% Zn with the diameter less than 0.4 μm through casting, hot extruding and multi-pass cold drawing combined with intermediated annealing process. Their microstructures, mechanical and degradation properties were investigated. In comparison with the corresponding as-extruded alloy, the final fine wire has significantly refined grain with an average size of 3–4 μm, and meanwhile shows higher yield strength but lower ductility at room temperature. The degradation tests results and surface morphologies observations indicate that Mg–4Gd–0.4Zn and Mg–4Nd–0.4Zn fine wires have similar good corrosion resistance and the uniform corrosion behavior in SBF solution. By contrast, Mg–4Y–0.4Zn fine wire shows a poor corrosion resistance and the pitting corrosion behavior.     

铜基纳米材料在增强化学动力学治疗上的应用研究

和传统治疗相比,化学动力学治疗(CDT)被认为是一种低副作用且无创的治疗方法,在众多的治疗方法中脱颖而出.CDT通过金属离子介导的芬顿反应或类芬顿反应,将肿瘤中过表达的过氧化氢(H2O2)分解为剧毒的羟基自由基(·OH),从而杀死肿瘤细胞.近年来,铜基纳米材料在CDT中蓬勃发展,极大地提高了CDT的效率.因此,基于铜基...     

合肥光源束测系统的最新研究进展

介绍了合肥光源束测系统的最新进展及其研究工作，包括200MeV直线加速器BPM系统的研制和测量，利用交流K调制的基于束流准直测量研究，基于对数比处理技术的同步光位置测量系统的研制以及数字束流位置处理器的应用研究．直线加速器BPM系统已安装，并做了在线的束流位置测量实验，给出了测量结果．在合肥光源储存环上利用双向固态继电器开关可以对32块四极铁进行交流K调制，采用数字锁相放大和插值快速傅立叶分析算法进行了基于束流准直的交流K调制测量实验和研究，给出了实验结果．利用高精度对数运算放大器LOG112研制了基于对数比处理技术的同步光位置测量系统，其性能优于常用的差比和处理技术．利用数字束流位置处理器Libera在合肥光源储存环上完成了工作点、相空间和横向振荡阻尼时间常数等的测量，并取得了很好的结果．     

Graphene-based ambipolar electronics for radio frequency applications

Graphene is considered as a promising material to construct field-effect transistors (FETs) for high frequency electronic applications due to its unique structure and properties,mainly including extremely high carrier mobility and saturation velocity,the ultimate thinnest body and stability.Through continuously scaling down the gate length and optimizing the structure,the cut-off frequency of graphene FET (GFET) was rapidly increased and up to about 300 GHz,and further improvements are also expected.Because of the lack of an intrinsic band gap,the GFETs present typical ambipolar transfer characteristic without off state,which means GFETs are suitable for analog electronics rather than digital applications.Taking advantage of the ambipolar characteristic,GFET is demonstrated as an excellent building block for ambipolar electronic circuits,and has been used in applications such as highperformance frequency doublers,radio frequency mixers,digital modulators,and phase detectors.     

交流电气传动的现状与发展

从器件、装置和应用等三个方面介绍了交流变速电气传动的发展现状和今后发展的趋势．     

Recent advances in additive-enhanced magnesium hydride for hydrogen storage

The discovery of new hydrogen storage materials has greatly driven the entire hydrogen storage technology forward in the past decades. Magnesium hydride, which has a high hydrogen capacity and low cost, has been considered as one of the most promising candidates for hydrogen storage. Unfortunately, extensive efforts are still needed to better improve its hydrogen storage performance, since MgH2 suffers from high operation temperature, poor dehydrogenation kinetic, and unsatisfactory thermal management. In this paper, we present an overview of recent progress in improving the hydrogenation/de-hydrogenation performance of MgH2, with special emphases on the additive-enhanced MgH2 composites. Other widely used strategies (e. g. alloying, nanoscaling, nanoconfinement) in tuning the kinetics and thermodynamics of MgH2 are also presented. A realistic perspective regarding to the challenges and opportunities for further researches in MgH2 is proposed.     

Recent advances in the data analysis method of functional magnetic resonance imaging and its applications in neuroimaging

Functional magnetic resonance imaging (fMRI) has opened a new area to explore the human brain. The fMRI can reveal the deep insights of spatial and temporal changes underlying a broad range of brain function, such as motor, vision, memory and emotion, all of which are helpful in the clinical investigation. In this paper, we introduce some recent-developed algorithms for fMRI signal detection such as model-driven method (general linear model, deconvolution model, non-linear model, etc.) and data-driven method (principle component analysis, independent component analysis, self-organization mapping, clustered constrained non-negative matrix factorization, etc.). We also propose several important applications of neuroimaging and point out their shortcomings and future perspectives.     

柔性机械臂动力学建模与控制方法研究进展

柔性机械臂具有质量轻、惯性小、能耗低等优点,随着机器人技术的发展,针对柔性机械臂的精确建模和有效控制成为国内外学者的重要研究课题。从柔性机械臂动力学建模和动力学控制方法两方面,介绍了近十年国内外学者的研究现状和最新技术的发展,在此基础上对各种方法的优缺点进行分析和比较,并对今后的发展进行了展望。     

应变调控柔性电子器件磁电性质的研究进展

柔性电子器件具有独特的形状可塑性,因而引起了人们极大的研究热情.柔性电子器件在未来或将成为下一代电子器件的重要分支,在电子显示、二极管、生物医疗器件、太阳能电池等领域有着广阔的发展前景.近些年,许多研究人员将柔性技术与自旋电子学相结合,开始探索应变对于生长在柔性衬底上的磁电异质结磁电性质的影响,通过改变柔性衬底的曲率等手段调控器件的磁电效应.相关基础研究为磁存储器、磁传感器、非易失性阻变存储器等电子器件的研究开辟了新思路.     

柔性导轨制孔机器人及变刚度技术研究现状

柔性导轨制孔机器人属于轻型自主移动式制孔设备当中的典型代表,具有小型化、成本低等特点,引起了国内外飞机制造厂商的重点关注。然而,由于导轨柔性不足,限制了其应用范围,只适合于飞机大部件、小曲率表面的制孔和装配。为解决此问题,扩大其应用范围,本文对柔性导轨制孔机器人、变刚度技术进行了综述,创新性的提出了变刚度柔性导轨技术与导轨制孔机器人技术相结合的方案。