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一维纳米材料（碳纳米管、纳米线、氧化物纳米带）作为研制纳电子器件理想的材料具有重要的科学意义和应用前景。本工作主要集中在氧化物纳米带、碳纳米管的功能化及其和纳米器件性质研究。 相似文献
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阳极氧化铝(AAO)模板法是一种能够实现低成本制备大面积图案化纳米结构的方法,在生物传感器、海水淡化以及光电器件等领域具有广阔的应用前景。AAO模板具有众多形貌,其中以倒锥形AAO模板制备的纳米锥结构能够有效地消除菲涅尔反射,被广泛应用于大面积图案化薄膜的制备以及改善传统光电器件的性能。本文以倒锥形AAO模板的制备及其应用为主题展开文献综述,介绍了倒锥形AAO模板的制备原理和方法,总结倒锥形AAO模板辅助制备聚合物、金属以及无机非金属图案化纳米结构的具体实验方法。随后,详细介绍倒锥形AAO模板辅助图案化纳米结构在光学减反层、宽谱光吸收体、超疏水表面等领域应用的研究进展。最后,本文总结了倒锥形AAO模板图案化技术所面临的一些问题和挑战,并对未来的发展做出展望。 相似文献
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概述准一维纳米结构材料包括纳米管、纳米线和纳米棒通过多种方法已经被成功制备出来,其独特的物理化学特性,在微电子器件方面有很好的应用前景,现在已经成为物理化学研究者争相研究的热点。ZnO是重要的Ⅱ－Ⅵ族直接带隙宽禁带半导体氧化物,其禁带宽度为3．37eV,激子结合能（60meV）,具有较高的化学稳定性,适宜用作室温或更高温度下的可见和紫外光发射材料。因此,合成准一维ZnO纳米结构及其性质研究迅速受到了科学工作者的广泛关注。基于气－固（VS）和气－液－固（VLS）生长机制,各种形貌的准一维ZnO纳米结构已经被国际上著名的纳米小组报道过,包括纳米带,纳米线阵列,单根纳米线器件,单晶纳米环,超品格纳米弹簧,纳米盘,微米棒等等。 相似文献
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以结构化学指导新型金属 有机纳米器件的合理合成和物理性能研究,探索它们的自组装规律,共设计合成了 1 2个含N、S及COO- 基团的具有不同对称性和立体选择性的新颖大骨架多官能团柔性配体,以及由它们与金属离子自组装合成了 1 8个新型金属 有机纳米笼、纳米管和配位聚合物,开辟了一条合成金属 有机纳米器件的新途经。其中,一个具有Oh对称的金属纳米笼,笼内体积超过 1 0 0 0 A3,可以同时容纳多种离子和小分子,是目前已测定单晶结构的金属纳米笼中容量最大的一个。而用金属离子把纳米管串联成的金属 有机纳米管则是国际上首例报道的结构有序无机 有机纳米管阵列;并创新性的采用低温溶剂热法合成了一个新颖的具有半导体和顺磁性质的Ni 巯基嘧啶二维层状聚合物和两个二维折叠格子状化合物;另外,用巯基嘧啶作为难溶盐CuCN的溶解模板,得到了国际上首例六角形CuCN大环化合物和另外一个新颖的类石墨层状CuCN化合物. 过渡金属与多官能团配体通过配位键来驱动和引导自组装,形成具有均一尺寸和特定形状的金属 有机纳米器件,是当今化学与材料领域研究的前沿之一。而通过设计合成具有特定对称性和立体选择性的有机配体,并把它们与金属离子自组装形成具有纳米尺寸和特殊功能的纳米球和纳米管,更是在纳米科技、 相似文献
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赵静 《科技成果管理与研究》2021,16(4):8-9
过渡金属配合物是一类重要的光功能分子材料,具有丰富的电化学、光吸收、三线态发光性能,在信息、光电器件、绿色能源等领域有重要用途.在这些应用中,分子材料通常以纳米薄膜或组装结构的形式被使用.然而金属配合物极性大、溶解性较差、分子间缺少有效相互作用,严重制约了其纳米薄膜和组装结构的制备. 相似文献
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<正>由多段异质材料纳米线与纳米管联结组成的纳米结构,是纳米光电子器件的重要组成单元;同时,这种结构在条形编码、光学读出、生物、催化、自组装和磁操纵等方面均有广泛的应用前景。最近,中科院固体物理研究所孟国文小组在"多段异质纳米线与纳米管组成的分支结构"研究方面 相似文献
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DNA纳米技术是设计和构建具有一定用途的人工核酸纳米结构。DNA纳米技术中的一个重要挑战就是如何有效设计和构建具有明确功能的纳米尺度的结构和器件。计算机辅助工具是预测、设计、建模以及描绘DNA结构的最强有力的工具。计算机辅助设计DNA结构以及识别有效的自组装路径让DNA作为一种独特的材料在构建纳米结构领域中显露锋芒。文章总结了DNA纳米结构设计的原理,介绍了一些用于DNA结构设计的算法以及一些用户友好软件。同时,对DNA纳米技术中构建DNA逻辑门以及DNA计算方面的最新研究进展做了介绍。 相似文献
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In this work we report a microfluidic platform capable of trapping and concentrating a trace amount of DNA molecules efficiently. Our strategy invokes nonlinear electro-osmotic flow induced by charge polarization under high-frequency ac fields. With the asymmetric quadrupole electrode design, a unique converging flow structure can be created for generating focusing effects on DNA molecules. This focusing in turn transforms into a robust funnel that can collect DNA molecules distantly from the bulk and pack them into a compact cone with the aid of short-range dipole-induced self-attraction and dielectrophoresis. Our results reveal that not only can DNA molecules be concentrated within just a few seconds, but also they can be focused into threads of 1 mm in length, demonstrating the superfast and long-range trapping capability of this funnel. In addition, pico M DNA solutions can be concentrated with several decades of enhancement without any continuous feeding. Alternating concentration and release of DNA molecules is also illustrated, which has potentials in concentrating and transporting biomolecules in a continuous fashion using microdevices. 相似文献
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《Information processing & management》2023,60(5):103434
This paper focuses on personalized outfit generation, aiming to generate compatible fashion outfits catering to given users. Personalized recommendation by generating outfits of compatible items is an emerging task in the recommendation community with great commercial value but less explored. The task requires to explore both user-outfit personalization and outfit compatibility, any of which is challenging due to the huge learning space resulted from large number of items, users, and possible outfit options. To specify the user preference on outfits and regulate the outfit compatibility modeling, we propose to incorporate coordination knowledge in fashion. Inspired by the fact that users might have coordination preference in terms of category combination, we first define category combinations as templates and propose to model user-template relationship to capture users’ coordination preferences. Moreover, since a small number of templates can cover the majority of fashion outfits, leveraging templates is also promising to guide the outfit generation process. In this paper, we propose Template-guided Outfit Generation (TOG) framework, which unifies the learning of user-template interaction, user–item interaction and outfit compatibility modeling. The personal preference modeling and outfit generation are organically blended together in our problem formulation, and therefore can be achieved simultaneously. Furthermore, we propose new evaluation protocols to evaluate different models from both the personalization and compatibility perspectives. Extensive experiments on two public datasets have demonstrated that the proposed TOG can achieve preferable performance in both evaluation perspectives, namely outperforming the most competitive baseline BGN by 7.8% and 10.3% in terms of personalization precision on iFashion and Polyvore datasets, respectively, and improving the compatibility of the generated outfits by over 2%. 相似文献
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In this work, invoking join asymmetric ac polarization using double half-quadrupole electrodes in a symmetric arrangement, we demonstrate a head-on ac electro-osmotic streaming capable of focusing and trapping DNA molecules efficiently. This is manifested by the observation that picomolar DNA molecules can be trapped into a large crosslike spot with at least an order of magnitude concentration enhancement within just half a minute. We identify that the phenomenon is a combined result of the formation of two prefocused DNA jets flowing toward each other, dipole-induced attraction between focused DNA molecules, and dielectrophoretic trap on the spot. With an additional horizontal pumping, we observe that the trap can transform into a peculiar pitchfork streaming capable of continuous collection and long-distance transport of concentrated DNA molecules. We also show that the same electrode design can be used to direct assembly of submicrometer particles. This newly designed microfluidic platform not only has potentials in enhancing detection sensitivity and facilitating functional assembly for on-chip analysis but also provides an added advantage of transporting target molecules in a focused and continuous manner. 相似文献
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Ordered deposition of elongated DNA molecules was achieved by the forced dewetting of a DNA solution droplet over a microstructured substrate. This technique allows trapping, uncoiling, and deposition of DNA fragments without the need of a physicochemical anchoring of the molecule and results in the combing of double stranded DNA from the edge of microwells on a polydimethylsiloxane (PDMS) substrate. The technique involves scanning a droplet of DNA solution caught between a movable blade and a PDMS substrate containing an array of microwells. The deposition and elongation appears when the receding meniscus dewets microwells, the latter acting here as a perturbation in the dewetting line forcing the water film to break locally. Thus, DNA molecules can be deposited in an ordered manner and elongated conformation based solely on a physical phenomenon, allowing uncoiled DNA molecules to be observed in all their length. However, the exact mechanism that governs the deposition of DNA strands is not well understood. This paper is an analysis of the physical phenomenon occurring in the deposition process and is based on observations made with the use of high frame/second rate video microscopy. 相似文献
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Materials of nanoscale size exhibit properties that macroscopic materials often do not have. The same holds for bubbles on the nanoscale: nanoscale gaseous domains on a solid-liquid interface have surprising properties. These include the shape, the long life time, and even superstability. Such so-called surface nanobubbles may have wide applications. This prospective article covers the basic properties of surface nanobubbles and gives several examples of potential nanobubble applications in nanomaterials and nanodevices. For example, nanobubbles can be used as templates or nanostructures in surface functionalization. The nanobubbles produced in situ in a microfluidic system can even induce an autonomous motion of the nanoparticles on which they form. Their formation also has implications for the fluid transport in narrow channels in which they form. 相似文献
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Investigation of single molecule DNA dynamics in confined environments has led to important applications in DNA analysis, separation, and sequencing. Here, we studied the electrophoretic transport of DNA molecules through nanochannels shorter than the DNA contour length and calculated the associated translocation time curves. We found that the longer T4 DNA molecules required a longer time to traverse a fixed length nanochannel than shorter λ DNA molecules and that the translocation time decreased with increasing electric field which agreed with theoretical predictions. We applied this knowledge to design an asymmetric electric pulse and demonstrate the different responses of λ and T4 DNA to the pulses. We used Brownian dynamics simulations to corroborate our experimental results on DNA translocation behaviour. This work contributes to the fundamental understanding of polymer transport through nanochannels and may help in designing better separation techniques in the future. 相似文献
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We studied the mobility of DNA molecules driven by an electric field through a nanofluidic device containing a periodic array of deep and shallow regions termed entropic traps. The mobility of a group of DNA molecules was measured by fluorescent video microscopy. Since the depth of a shallow region is smaller than the DNA equilibrium size, DNA molecules are trapped for a characteristic time and must compress themselves to traverse the boundary between deep and shallow regions. Consistent with previous experimental results, we observed a nonlinear relationship between the mobility and electric field strength, and that longer DNA molecules have larger mobility. In repeated measurements under seemingly identical conditions, we measured fluctuations in the mobility significantly larger than expected from statistical variation. The variation was more pronounced for lower electric field strengths where the trapping time is considerable relative to the drift time. To determine the origin of these fluctuations, we investigated the dependence of the mobility on several variables: DNA concentration, ionic strength of the solvent, fluorescent dye staining ratio, electroosmotic flow, and electric field strength. The mobility fluctuations were moderately enhanced in conditions of reduced ionic strength and electroosmotic flow. 相似文献
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DNA molecules in a solution can be immobilized and stretched into a highly ordered array on a solid surface containing micropillars by molecular combing technique. However, the mechanism of this process is not well understood. In this study, we demonstrated the generation of DNA nanostrand array with linear, zigzag, and fork-zigzag patterns and the microfluidic processes are modeled based on a deforming body-fitted grid approach. The simulation results provide insights for explaining the stretching, immobilizing, and patterning of DNA molecules observed in the experiments. 相似文献