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热烈祝贺郭万林教授当选中国科学院院士

11/28/2017 - 17:26

郭万林,固体力学博士,教授,南京航空航天大学纳米科学研究所所长,纳智能材料器件教育部重点实验室主任。1996年获国家杰出青年基金,1999年受聘为国家教育部“长江学者”特聘教授到南京航空航天大学工作,开展交叉学科前沿及其在未来空天技术中的应用研究,创建南京航空航天大学纳米科学研究所、纳米力学硕士与博士点、“纳智能材料器件”工信部重点学科、纳智能材料结构与仿生工程国防重点学科。2005年作为学术带头人的“纳尺度物理力学”团队入选国家教育部“长江学者创新团队”计划,2008年入选江苏省首届攀登计划,2010年成功申请建设教育部“纳智能材料器件”重点实验室,2011年,南航成功申请 “机械结构力学及控制国家重点实验室”, 作为学术带头人的微纳系统力学为其五个研究方向之一,2012年获全国优秀科技工作者称号,2013年获徐芝纶力学一等奖,2014年获江苏省有突出贡献中青年专家称号。曾于美国、德国、澳大利亚、波兰工作和访学,并在多国讲学。
郭万林教授长期从事飞机结构强度和材料力学研究。建立了三维弹塑性断裂理论以及三维断裂准则和疲劳裂纹扩展寿命预测方法,解决了军机研制中的三维损伤容限设计关键技术;提出了低维体系局域场和外场耦合的概念,构建了低维纳米材料结构力-电-热-磁耦合的物理力学理论体系,发现了纳米智能材料中新的概念和器件原理,拓展了经典动电理论,推动了从力学理论到工程环境下能量转化新效应和亚纳米制造的跨越。
在Nature Nanotech.,Nature Commun., Phys. Rev. Lett., J. Am. Chem. Soc., Nano Lett., Adv. Mater.等国际一流学术刊物上发表SCI论文280余篇,被SCI源刊物引用5400多次,连续多年入选中国高被引学者,被Nature集团多次亮点报道,获授权国家发明专利9项。部分成果获2012年度国家自然科学二等奖一项和2011年度高等学校科学研究优秀成果奖自然科学一等奖一项。主持国家973计划课题,国家自然科学基金重点项目、面上项目等。已培养博士38人,其中杰青1人、优青2人、青千2人、全国优博2人、优博提名3人。

4 Water-evaporation-induced electricity with nanostructured carbon materials

01/30/2017 - 11:26

Water evaporation is a ubiquitous natural process that harvests thermal energy from the ambient environment. It has previously been utilized in a number of applications including the synthesis of nanostructures and the creation of energyharvesting
devices. Here, we show that water evaporation from the surface of a variety of nanostructured carbon materials can be used to generate electricity. We find that evaporation from centimetre-sized carbon black sheets can reliably generate
sustained voltages of up to 1 V under ambient conditions. The interaction between the water molecules and the carbon layers and moreover evaporation-induced water flow within the porous carbon sheets are thought to be key to the voltage
generation. This approach to electricity generation is related to the traditional streaming potential, which relies on driving ionic solutions through narrow gaps, and the recently reported method of moving ionic solutions across graphene surfaces, but as it exploits the natural process of evaporation and uses cheap carbon black it could offer advantages in the development of practical devices.

Hydroelectric generator from transparent flexible zinc oxide nanofilms

11/25/2016 - 11:06

Harvesting wave energy based on waving potential, a newly found electrokinetic effect, is attractive but limited mainly to monolayer graphene. Here we demonstrate that moving a transparent flexible ZnO nanofilm across the surface of ionic solutions can generate electricity. The generated electricity increases linearly with the
moving velocity with an open-circuit voltage up to tens of millivolt and a short-circuit current at the order of microampere. The harvested electricity can be efficiently scaled up through series and parallel connections. Theoretical simulations show that it is the proper electrical property that endows the ZnO nanofilm with the outstanding capacity in harvesting the wave energy.

Boron Nitride Nanostructures: Fabrication, Functionalization and Applications

04/13/2016 - 10:18

Boron nitride (BN) structures are featured by their excellent thermal and chemical stability and unique electronic and optical properties. However, the lack of controlled synthesis of quality samples and the electrically insulating property largely prevents realizing the full potential of BN nanostructures. This review provides a comprehensive overview of the current status of the synthesis of two dimensional hexagonal BN sheets, three dimensional porous hexagonal BN materials and BN-related heterostructures, highlighting the advantages of different synthetic methods. In addition, structural characterization, functionalizations and prospective applications of hexagonal BN sheets are intensively discussed. One-dimensional BN nanoribbons and nanotubes are then discussed in terms of structure, fabrication and functionality. In particular, the existing arts in pursuit of tunable electronic and magnetic properties in various BN structures are surveyed, calling upon synergetic experimental and theoretical efforts to address the challenges for pioneering the applications of BN into functional devices. Finally, the progress on BN superstructures and novel B nanostructures is briefly introduced.

Tunable electronic and magneticproperties of two-dimensionalmaterials and theirone-dimensional derivatives

03/15/2016 - 11:16

Low-dimensional materials exhibit many exceptional properties and functional-ities which can be efficiently tuned by externally applied force or fields. Here wereview the current status of research on tuning the electronic and magnetic prop-erties of low-dimensional carbon, boron nitride, metal-dichalcogenides, phos-phorene nanomaterials by applied engineering strain, external electric field andinteraction with substrates, etc, with particular focus on the progress of computa-tional methods and studies. We highlight the similarities and differences of theproperty modulation among one- and two-dimensional nanomaterials. Recent breakthroughs in experimental demonstration of the tunable functionalities intypical nanostructures are also presented. Finally, prospective and challenges forapplying the tunable properties into functional devices are discussed.

Large-Area, Periodic, Hexagonal Wrinkles on Nanocrystalline Graphitic Film

08/25/2015 - 15:28

Sinusoidal wrinkles develop in compressively stressed film as a means to release stored elastic energy. Here, a simple way to fabricate large-area, periodic, hexagonal wrinkled pattern on nanocrystalline graphitic films grown on c-plane sapphire (<50 nm thick) by the spontaneous delamination–buckling of the as-grown film during cooling is reported. According to the continuum mechanics calculation, strain-relief pattern adopting the hexagonal wrinkled pattern has a lower elastic energy than that of the telephone cord wrinkle at thickness regime below 50 nm. A high-fidelity transfer method is developed to transfer the hexagonal wrinkled films onto arbitrary substrates. Nanoindentation studies show that hexagonal wrinkle film engineered this way may act as shock absorber. The hexagonal wrinkled carbon film is able to selectively promote the differentiation of human mesenchymal stem cell toward the osteogenic lineage in the absence of osteogenic inducing medium.

Large Single-Crystal Hexagonal Boron Nitride Monolayer Domains with Controlled Morphology and Straight Merging Boundaries

06/15/2015 - 10:13

Hexagonal boron nitride monolayers with domain sizes up to 700 μm2 and geometry from triangle to hexagon are fabricated through a refined control over the precursor and morphology of the copper substrate. Hydrogen etching is shown to tailor the h-BN monolayers precisely along the grain boundaries, providing their morphology over micro­meter scale and a new avenue toward fabricating nanoribbons.

Low-voltage Driven Graphene Foam Thermoacoustic Speaker

06/14/2015 - 21:26


A low-voltage-driven thermoacoustic speaker is fabricated using graphene foams synthesized by a chemical vapor deposition method. When an audio signal is applied to the speaker, sound waves are produced due to the periodicity of air vibrations induced by Joule heating.

A low-voltage-driven thermoacoustic speaker is fabricated by W. Guo and co-workers using graphene foams synthesized by a chemical vapor deposition method. When an audio signal is applied to the speaker, sound waves are produced due to the periodicity of air vibrations induced by Joule heating. With the feasible tunability in structure and thermoacoustic performance, the graphene foam-based thermoacoustic speaker is shown to be promising for applications requiring flexible or ultrasonic acoustic devices

2D materials: Metallic when narrow

06/04/2014 - 13:22


Subnanometre metallic wires can be engineered from semiconducting sheets of transition-metal dichalcogenides by means of a focused electron beam.

Reducing the size of a crystal to the nanoscale can lead to a rearrangement of its atomic lattice and the creation of new material properties. Such rearrangements have been observed before in thin films and narrow wires fabricated from bulk materials of a single element1, 2. The use of materials made from more than one element has the potential to offer additional degrees of freedom because the composition of the crystals can also be modified3, and the atomic rearrangement of such structures has already been investigated using top-down methodologies such as electron-beam lithography4. Molybdenum sulphide ribbons with a width of around 0.35 nm have, for example, been fabricated by creating holes in a MoS2 sheet using electron irradiation in a transmission electron microscope (TEM)4. Writing in Nature Nanotechnology, Junhao Lin, Wu Zhou and colleagues now report the fabrication of subnanometre wires in MoS2 and other semiconducting transition-metal dichalcogenide sheets, and show that these nanowires are metallic5.

Bending Poisson Effect in Two-Dimensional Crystals

05/21/2014 - 13:35


As the Poisson effect formulates, lateral strains in a material can be caused by a uniaxial stress in the perpendicular direction, but no net lateral strain should be induced in a thin homogeneous elastic plate subjected to a pure bending load. Here, we demonstrated by ab initio simulations that significant exotic lateral strains can be induced by pure bending in two-dimensional crystals, in which the lateral components of chemical bonds can respond to bending curvature directly. The bending Poisson ratio, defined as the ratio of lateral strain to the curvature, is a function of curvature depending on chemical constitution, bonding structure, and atomic interaction of the crystal, and is anisotropic.

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