共查询到20条相似文献，搜索用时 250 毫秒
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1911年4月8日,荷兰物理学家卡麦林·昂尼斯首次意外地发现了超导现象:将水银冷却到绝对零度时,其电阻突然消失。后来他发现铝、锡等金属与合金与水银有类似的特性——在低温下电阻为零,昂尼斯称之为超导态。1913年他因此获得诺贝尔物理学奖。之后科学家们纷纷探索超导的应用,但早期应用均遭失败。 相似文献
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杜仲 《大科技．科学之谜》2010,(7):50-51
<正>这篇文章由河北宣化的夏贤等读者点题,不知道你们对该文的回答满不满意,欢迎来信告诉我们。意外迭生的超导史所谓超导就是某些材料在低温下电阻突然降为零的现象。大多数金属或者合金材料在温度降到足够低时都可以实现超导。绝大多数绝缘体都没有超导的特性,但也有极少数例外,这些例外下面很快就会谈到。 相似文献
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超导材料指的是在超低温下失去电阻的材料。它的这种性质就是超导电性。具有超导电性的物质称为超导体。低温超导材料发展于上个世纪80年代中期之前,高温超导材料出现在其之后。高温超导材料的发展为超导技术的应用展现前景。本文主要阐述了超导体在信息技术、宇航航海机械制造技术、交通领域和电力技术领域等方面的应用问题。 相似文献
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超导是指在温度接近绝对零度的时候导电材料的电阻趋近于0的性质。"超导体"是指能进行超导传输的导电材料。人类最初发现物体的超导现象是在1911年,当时荷兰科学家海克·卡末林·昂内斯等人发现,某些材料在极低的温度下,其电阻完全消失。 相似文献
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在柏莱兹和缪勒发现 Ba-La-Cu 氧化物超导材料之后,赵忠贤等合成了液氮温区 Ba-Y-Cu 氧化物超导材料,很快开始了 Ba-Y-Cu 氧化物超导膜的研究。今年二月初中科院物理研究所合成了 Bi-Sr-Ca-Cu 氧化物超导材料,电阻从115K 开始下降,零电阻温度为78K。我们于2月中旬研制成了 Bi-Sr-Ca-Cu 氧化物超导厚膜,经四电极法测定电阻随温 相似文献
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中国科学院物理研究所 《中国科学院院刊》2016,31(Z1):49-50
正超导电性是荷兰科学家Onnes在1911年发现的,它是指某些材料在其临界温度以下表现出零电阻和完全抗磁性的现象,相应的材料称为超导体。如果超导体临界温度在常压下高于传统理论认为的"麦克米兰极限"(40K),则称为高温超导体。超导是20世纪最伟大的科学发现之一,在其研究历史上,已经有10人获得了5次诺贝尔奖。目前,超 相似文献
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一个经济实用的商用堆必须是高效、紧凑和稳态运行的。未来商用堆必须是全超导,才能实现稳态运行。我国超导托卡马克研究始于1991年,在将原苏联T7超导托卡马克改成HT-7后并在其上做了许多有意义的工作。1997年开始全超导托卡马克EAST计划,2006年建成并投入运行。未来将在长脉冲条件下进行高参数等离子物理实验,为未来稳态、先进聚变实验反应堆奠定良好的工程技术和物理基础。 相似文献
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Hongyu Luo Chengjun Wang Changhong Linghu Kaixin Yu Chao Wang Jizhou Song 《国家科学评论(英文版)》2020,7(2):296
Transfer printing, as an important assembly technique, has attracted much attention due to its valuable merits to develop novel forms of electronics such as stretchable inorganic electronics requiring the heterogeneous integration of inorganic materials with soft elastomers. Here, we report on a laser-driven programmable non-contact transfer printing technique via a simple yet robust design of active elastomeric microstructured stamp that features cavities filled with air and embedded under the contacting surface, a micro-patterned surface membrane that encapsulates the air cavities and a metal layer on the inner-cavity surfaces serving as the laser-absorbing layer. The micro-patterned surface membrane can be inflated dynamically to control the interfacial adhesion, which can be switched from strong state to weak state by more than three orders of magnitude by local laser heating of the air in the cavity with a temperature increase below 100°C. Theoretical and experimental studies reveal the fundamental aspects of the design and fabrication of the active elastomeric microstructured stamp and the operation of non-contact transfer printing. Demonstrations in the programmable transfer printing of micro-scale silicon platelets and micro-scale LED chips onto various challenging receivers illustrate the extraordinary capabilities for deterministic assembly that are difficult to address by existing printing schemes, thereby creating engineering opportunities in areas requiring the heterogeneous integration of diverse materials such as curvilinear electronics and MicroLED displays. 相似文献
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有机硅-丙烯酸树脂共聚方法述评 总被引：2，自引：0，他引：2
有机硅具有低表面张力，低玻璃化温度、良好的耐水、耐温、耐候等性能，这些优越性能为有机硅在高分子材料科学中的应用起着极为重要的作用。然而，由于有机硅的成本高、附着力及成膜性能较差，使它的进一步应用受到限制。鉴于此，许多有机硅工作者利用丙烯酸类物质对有机硅进行改性，不仅可以改善有机硅的缺点，而且还可以赋予这种复合材料许多新的性能。近年来，随着有机硅-丙烯酸树脂共聚物研究的不断深入，各种聚合方法也不断涌现。本文将以有机硅-丙烯酸树脂复合材料的类型为基础，对其中一些主要聚合方法的原理、优、缺点以及应用进行了比较详细的述评。 相似文献
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We review recent progress in the exploration of topological quantum states of matter in iron-based superconductors. In particular, we focus on the non-trivial topology existing in the band structures and superconducting states of iron’s 3d orbitals. The basic concepts, models, materials and experimental results are reviewed. The natural integration between topology and high-temperature superconductivity in iron-based superconductors provides great opportunities to study topological superconductivity and Majorana modes at high temperature. 相似文献
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Ying Xing Zhibin Shao Jun Ge Jiawei Luo Jinhua Wang Zengwei Zhu Jun Liu Yong Wang Zhiying Zhao Jiaqiang Yan David Mandrus Binghai Yan Xiong-Jun Liu Minghu Pan Jian Wang 《国家科学评论(英文版)》2020,7(3):579
The search for unconventional superconductivity in Weyl semimetal materials is currently an exciting pursuit, since such superconducting phases could potentially be topologically non-trivial and host exotic Majorana modes. The layered material TaIrTe4 is a newly predicted time-reversal invariant type II Weyl semimetal with the minimum number of Weyl points. Here, we report the discovery of surface superconductivity in Weyl semimetal TaIrTe4. Our scanning tunneling microscopy/spectroscopy (STM/STS) visualizes Fermi arc surface states of TaIrTe4 that are consistent with the previous angle-resolved photoemission spectroscopy results. By a systematic study based on STS at ultralow temperature, we observe uniform superconducting gaps on the sample surface. The superconductivity is further confirmed by electrical transport measurements at ultralow temperature, with an onset transition temperature (Tc) up to 1.54 K being observed. The normalized upper critical field h*(T/Tc) behavior and the stability of the superconductivity against the ferromagnet indicate that the discovered superconductivity is unconventional with the p-wave pairing. The systematic STS, and thickness- and angular-dependent transport measurements reveal that the detected superconductivity is quasi-1D and occurs in the surface states. The discovery of the surface superconductivity in TaIrTe4 provides a new novel platform to explore topological superconductivity and Majorana modes. 相似文献
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This review article presents how microfluidic technologies and biological materials are paired to assist in the development of low cost, green energy fuel cell systems. Miniaturized biological fuel cells, employing enzymes or microorganisms as biocatalysts in an environmentally benign configuration, can become an attractive candidate for small-scale power source applications such as biological sensors, implantable medical devices, and portable electronics. State-of-the-art biofuel cell technologies are reviewed with emphasis on microfabrication compatibility and microfluidic fuel cell designs. Integrated microfluidic biofuel cell prototypes are examined with comparisons of their performance achievements and fabrication methods. The technical challenges for further developments and the potential research opportunities for practical cell designs are discussed. 相似文献
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未来汽车电子发展的重要技术趋势 总被引：1，自引：0，他引：1
未来汽车电子发展将有三大趋势,即绿色环保、安全和舒适。本文将对三大趋势加以分析,这三大趋势与目前全球整个汽车市场的走势相关,整车厂商与汽车电子零部件供应商的同步开发成为成为汽车产品开发的主流模式。 相似文献
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Ye Yuan Yinwei Li Guoyong Fang Guangtao Liu Cuiying Pei Xin Li Haiyan Zheng Ke Yang Lin Wang 《国家科学评论(英文版)》2019,6(3):524
The superconductivity of hydrides under high pressure has attracted a great deal of attention since the recent observation of the superconducting transition at 203 K in strongly compressed H2S. It has been realized that the stoichiometry of hydrides might change under high pressure, which is crucial in understanding the superconducting mechanism. In this study, PH3 was studied to understand its superconducting transition and stoichiometry under high pressure using Raman, IR and X-ray diffraction measurements, as well as theoretical calculations. PH3 is stable below 11.7 GPa and then it starts to dehydrogenate through two dimerization processes at room temperature and pressures up to 25 GPa. Two resulting phosphorus hydrides, P2H4 and P4H6, were verified experimentally and can be recovered to ambient pressure. Under further compression above 35 GPa, the P4H6 directly decomposed into elemental phosphorus. Low temperature can greatly hinder polymerization/decomposition under high pressure and retains P4H6 up to at least 205 GPa. The superconductivity transition temperature of P4H6 is predicted to be 67 K at 200 GPa, which agrees with the reported result, suggesting that it might be responsible for superconductivity at higher pressures. Our results clearly show that P2H4 and P4H6 are the only stable P–H compounds between PH3 and elemental phosphorus, which is helpful for shedding light on the superconducting mechanism. 相似文献
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激光技术是高科技的产物,其产生又推动了科学研究的深入发展,并开拓出许多新的学科领域,激光在电子工业中也得到广泛应用。 相似文献
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We classify gapped topological superconducting (TSC) phases of one-dimensional quantum wires with local magnetic symmetries, in which the time-reversal symmetry is broken, but its combinations with certain crystalline symmetries, such as , , and , are preserved. Our results demonstrate that an equivalent BDI class TSC can be realized in the or superconducting wire, which is characterized by a chiral Zc invariant. More interestingly, we also find two types of totally new TSC phases in the and superinducting wires, which are beyond the known AZ class, and are characterized by a helical Zh invariant and Zh⊕Zc invariants, respectively. In the Zh TSC phase, Z pairs of Majorana zero modes (MZMs) are protected at each end. In the case, the MZMs can be either chiral or helical, and even helical-chiral coexisting. The minimal models preserving or symmetry are presented to illustrate their novel TSC properties and MZMs. 相似文献