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研制成功超高强度和塑性的金属玻璃和新型金属塑料物理研究所汤美波等人最近在前期工作的基础上,成功研制出具有超高强度和塑性的CuZr基金属玻璃材料。该材料断裂强度达2265MPa,同时具有一般非晶材料中不具备的加工硬化效应,尤其特别的是该材料具有极大的延展性(延展率为20%,而一般非晶合金材料的只有2%)。这同时也是世界上首次用一般金属材料制取塑性非晶合金材料。该材料的研制成功意味着大块非晶材料的应用范围可能大大被拓宽,可能会改变人们对非晶材料的认识。同时为设计新的具有塑性的金属玻璃材料提供了实验依据和方向。相关成果发… 相似文献
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我国金属材料随着科技的不断发展而逐年研发新型的和合金型材料,在现代具有代表性的合金材料是镁合金、铝合金两种。从金属材料自身的特点来说合金具备以下几种优点：密度小,减轻金属材料自重;强度高,合金的强度单一的金属材料最具备典型的代表就是钢铁问题,耐腐蚀,化学抗腐蚀能力好,针对铝合金材料的发展是伴随技术的研发,本文针对热处理技术进行介绍分析。 相似文献
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本文系统地研究了不同非晶合金材料的拉伸、压缩变形与断裂特征,总结了不同非晶合金材料拉伸与压缩断裂的不对称性,观察到具有剪切变形行为的非晶合金,其压缩塑性随样品的高径比减小而逐渐增加;提出了剪切带旋转机制来解释具有高塑性非晶合金材料压缩变形过程中剪切带的偏转,总结了钨丝和原位析出枝晶对非晶合金复合材料韧化效果的不同作用,讨论非晶合金材料压缩剪切断裂、劈裂和破碎的竞争关系。 相似文献
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中国科学院金属研究所 《中国科学院院刊》2016,31(Z1):39-40
正金属材料的强化是材料领域的长期核心研究方向。目前金属材料传统的强化技术均会使材料的塑性、韧性、导电性、热稳定性等显著下降。金属材料强度-塑性/韧性/导电性等的"倒置"关系限制了金属材料在更高水平和更广范围的应用,成为制约金属材料发展和应用的主要瓶颈。如何通过调控金属材料的微观组织结构和内 相似文献
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本文从非晶合金的特性出发,通过一系列的理论分析了非晶合金材料的特性对变压器特性的影响,尤其是时磁滞和涡流损耗的影响,从而阐述了非晶合金变压器有着较小的空载损耗,并通过实际的经济比较说明了非晶合金变压器在应用中的优势。 相似文献
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本文研究了不同非晶合金材料的拉伸、压缩变形与断裂特征,总结了不同非晶合金材料拉伸与压缩断裂的不对称性,观察到具有剪切变形行为的非晶合金,其压缩塑性随样品的高径比减小而逐渐增加;提出了剪切带旋转机制来解释具有高塑性非晶合金材料压缩变形过程中剪切带的偏转. 相似文献
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The six-membered ring (SMR) is a common structure unit for numerous material systems. These materials include, but are not limited to, the typical two-dimensional materials such as graphene, h-BN, and transition metal dichalcogenides, as well as three-dimensional materials such as beryllium, magnesium, MgB2 and Bi2Se3. Although many of these materials have already become ‘stars’ in materials science and condensed-matter physics, little attention has been paid to the roles of the SMR unit across a wide range of compositions and structures. In this article, we systematically analyze these materials with respect to their very basic SMR structural unit, which has been found to play a deterministic role in the occurrence of many intriguing properties and phenomena, such as Dirac electronic and phononic spectra, superconductivity and topology. As a result, we have defined this group of materials as SMR inorganic materials, opening up a new perspective on materials research and development. With their unique properties, SMR materials deserve wide attention and in-depth investigation from materials design, new physical discoveries to target-wizard applications. It is expected that SMR materials will find niche applications in next-generation information technology, renewable energy, space, etc. 相似文献
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全球科技发展态势研判是对未来一段时期科学技术、国际竞争、产业形态和社会关系的趋势判断和分析,对做好科技战略制定和规划具有重要意义。本文以2035年为展望,对全球科技发展、创新范式、基础科学、研发组织、社会影响进行态势分析,认为未来科技创新将对人类经济社会发展产生决定性影响,新技术、新组织、新产业、新业态将不断涌现,新型研发组织发生进阶化演变,技术应用将重塑经济社会和产业结构。中国作为科技创新领域进展最快的国家之一,面临着中美科技局部脱钩、国际技术出口管制、新兴技术应用受限、科研伦理不确定性增多等潜在风险。对此,提出应加强对战略前沿技术的前瞻性预测,加强国家科技合作,构建国家战略科技力量,构建核心技术攻关新型举国体制,加快政府管理职能转变等五方面措施。 相似文献
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信息社会的飞速发展对信息存储、加工、传输能力提出了与日俱增的迫切需求。随着“摩尔定律”逐渐逼近极限,半导体工业急需寻求新的解决方案。二维材料因为原子级厚度的尺寸特点,表面无悬挂键的结构优势加上极大比表面积导致的对电、光等调控手段的敏感性被认为是“后摩尔定律”时代半导体工业新的突破口。松山湖材料实验室引进一批国内外顶级科学家,组建二维材料团队,以基础科研为根基,以工程应用为导向,重点攻关其中关键问题。其目标在于取得有世界级重大影响力的科研成果,布局我国二维材料产业。 相似文献
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科研管理工作是高校工作的一个重要内容,现在高校越来越重视科研,导致科研项目繁多,增加了科研管理部门的工作量。针对这一现象,设计了高校科研管理系统,介绍了基于Web Services的B／S结构的关键技术,重点阐述了系统架构设计、功能设计以及实现方法。通过运用先进技术和工具对高校科研管理工作进行分析和抽象,将其信息化和规范化,降低开发成本,提高系统开发效率,对基于Web Services的系统开发提供了一种借鉴模式。 相似文献
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Ronald Pethig 《Biomicrofluidics》2010,4(2)
A review is presented of the present status of the theory, the developed technology and the current applications of dielectrophoresis (DEP). Over the past 10 years around 2000 publications have addressed these three aspects, and current trends suggest that the theory and technology have matured sufficiently for most effort to now be directed towards applying DEP to unmet needs in such areas as biosensors, cell therapeutics, drug discovery, medical diagnostics, microfluidics, nanoassembly, and particle filtration. The dipole approximation to describe the DEP force acting on a particle subjected to a nonuniform electric field has evolved to include multipole contributions, the perturbing effects arising from interactions with other cells and boundary surfaces, and the influence of electrical double-layer polarizations that must be considered for nanoparticles. Theoretical modelling of the electric field gradients generated by different electrode designs has also reached an advanced state. Advances in the technology include the development of sophisticated electrode designs, along with the introduction of new materials (e.g., silicone polymers, dry film resist) and methods for fabricating the electrodes and microfluidics of DEP devices (photo and electron beam lithography, laser ablation, thin film techniques, CMOS technology). Around three-quarters of the 300 or so scientific publications now being published each year on DEP are directed towards practical applications, and this is matched with an increasing number of patent applications. A summary of the US patents granted since January 2005 is given, along with an outline of the small number of perceived industrial applications (e.g., mineral separation, micropolishing, manipulation and dispensing of fluid droplets, manipulation and assembly of micro components). The technology has also advanced sufficiently for DEP to be used as a tool to manipulate nanoparticles (e.g., carbon nanotubes, nano wires, gold and metal oxide nanoparticles) for the fabrication of devices and sensors. Most efforts are now being directed towards biomedical applications, such as the spatial manipulation and selective separation∕enrichment of target cells or bacteria, high-throughput molecular screening, biosensors, immunoassays, and the artificial engineering of three-dimensional cell constructs. DEP is able to manipulate and sort cells without the need for biochemical labels or other bioengineered tags, and without contact to any surfaces. This opens up potentially important applications of DEP as a tool to address an unmet need in stem cell research and therapy. 相似文献
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Electrospinning, a flexible jet-based fiber, scaffold, and membrane fabrication approach, has been elucidated as having significance to the heath sciences. Its capabilities have been most impressive as it possesses the ability to spin composite fibers ranging from the nanometer to the micrometer scale. Nonetheless, electrospinning has limitations and hazards, negating its wider exploration, for example, the inability to handle highly conducting suspensions, to its hazardous high voltage. Hence, to date electrospinning has undergone an exhaustive research regime to a point of cliché. Thus, in the work reported herein we unveil a competing technique to electrospinning, which has overcome the above limitations and hazards yet comparable in capabilities. The fiber preparation approach unearthed herein is referred to as “pressure driven spinning (PDS).” The driving mechanism exploited in this fiber spinning process is the pressurized by-pass flow. This mechanism allows the drawing of either micro- or nanosized fibers while processing polymeric suspensions containing a wide range of advanced materials spanning structural, functional, and biological entities. Similar to electrospinning if the collection time of these continuous formed fibers is varied, composite scaffolds and membranes are generated. In keeping with our interests, multicompositional structural entities such as these could have several applications in biology and medicine, for example, ranging from the development of three-dimensional cultures (including disease models) to the development of synthetic tissues and organ structures to advanced approaches for controlled and targeted therapeutics. 相似文献
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In a crystalline material, structural defects such as dislocations or twins are well defined and largely determine the mechanical and other properties of the material. For metallic glass (MG) with unique properties in the absence of a long-range lattice, intensive efforts have focused on the search for similar ‘defects’. The primary objective has been the elucidation of the flow mechanism of MGs. However, their atomistic mechanism of mechanical deformation and atomic flow response to stress, temperature, and failure, have proven to be challenging. In this paper, we briefly review the state-of-the-art studies on the dynamic defects in metallic glasses from the perspective of flow units. The characteristics, activation and evolution processes of flow units as well as their correlation with mechanical properties, including plasticity, strength, fracture, and dynamic relaxation, are introduced. We show that flow units that are similar to structural defects such as dislocations are crucial in the optimization and design of metallic glassy materials via the thermal, mechanical and high-pressure tailoring of these units. In this report, the relevant issues and open questions with regard to the flow unit model are also introduced and discussed. 相似文献
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高端装备制造业是我国的七大战略性新兴产业之一，国家出台了一系列创新政策支持其发展。本文收集了2006-2017年间高端装备制造业的67项创新政策以及专利数量、新产品销售收入等数据，通过量化评估政策文本、构建结构方程模型等方法研究创新政策对专利数量、新产品销售收入等创新产出的影响，结果发现，第一，技术创新规划、研究开发活动、产业化活动等对专利产出、新产品销售收入等具有不同程度的推动作用；第二，我国高端装备制造业创新政策已经走出宏观勾画轮廓的初级阶段，趋向于专业化和精细化；第三，创新政策存在着对科技成果转化重视不足、核心部门联合颁发的政策较少、力度不强等问题。 相似文献