北京时间 10 月 23 日晚 8 点，大家期待已久的 iCANX Talks 第二十八期即将重磅来袭，本期直播将迎来世界顶尖光学期刊 Light: Science Applications 与 iCANX Talks 联合发起的 Light 学术新星评选活动，从 7 月份正式发出通知，共有世界各地的 35 位优秀青年科学家获得提名，经过严格的筛选最终有 10 位杰出的青年科学家入围最终的角逐，他们将在 23 日和 30 日的 iCANX Talks 上进行最终的评选，每人做 20 分钟的演讲，并接受 5 位世界顶级光学专家组成的评审团的提问和评议。 五位评委分别是来自加利福尼亚大学洛杉矶分校的 Aydogan Ozcan 教授、原科技部副部长曹健林、澳大利亚国立大学的 Chennupati Jagadish 教授、纽约市立大学的 Andrea Alù 教授、以及来自西湖大学的仇旻教授。本次 Light 学术新星评选活动设有 1 名一等奖， 2 名二等奖和 3 名三等奖，最终的比赛结果将在 30 日的 iCANX Talks 上揭晓。 本周率先即将登场的 5 位青年科学家是：来自科罗拉多大学博尔德分校孙硕教授、复旦大学的孙树林教授、美国范德堡大学的 Justus Ndukaife 教授、新加坡国立大学的胡光维博士、以及来自斯坦福大学的 Avik Dutt 。他们将在 iCANX Talks 的舞台上给大家带来一场精彩的学术竞赛。 在前 27 期的 iCANXTalks 直播中 , 累计收看观众已经近千万人次，受到了国内外专家学者的普遍好评和追捧，目前， iCANXTalks 已经成为极具国际影响力的高科技云端学术峰会。 话不多说，先让小艾给大家详细介绍五位青年科学家和他们的演讲内容吧！ 报告 1 Quantum nanophotonics: engineering atom-photon interactions on-a-chip 量子纳米光子学：在芯片上产生与调控原子与光子的相互作用 Shuo Sun 孙硕 University of Colorado Boulder 科罗拉多大学博尔德分校 Abstract The ability to engineer controllable atom-photon interactions is at the heart of quantum optics and quantum information processing. In this talk, I will introduce a nanophotonic platform for engineering strong atom-photon interactions on a semiconductor chip. I will first discuss an experimental demonstration of a spin-photon quantum switch , a fundamental building block for quantum repeaters and quantum networks. The device allows a single spin trapped inside a semiconductor quantum dot to switch a single photon, and vice versa, a single photon to flip the spin. I will discuss how the spin-photon quantum transistor realizes optical nonlinearity at the fundamental single quantum level, where a single photon could switch the transmission of multiple subsequent photons . Toward the end of this talk, I will highlight exciting applications of these devices in quantum networks and optical quantum information processing. 产生与调控原子和光子的相互作用是量子光学和量子信息处理的核心。在这次的讲座中，我将介绍一种利用纳米光学手段在半导体芯片上实现强原子光子相互作用的器件平台。首先，我将讨论我们实验上实现的耦合电子自旋和光子的量子开关。该量子开关可以利用单个电子的自旋态控制光子的偏振态，同时利用单个光子的偏振态控制电子的自旋，因而被视为量子中继器和量子网络的基础组件。我将接下来介绍我们如何利用这个器件实现单光子尺度的光学非线性现象。讲座的最后，我将阐述这些器件在量子网络和光量子信息领域的广泛应用前景。 Biography Shuo Sun is an associate fellow of JILA and an assistant professor of Physics at the University of Colorado Boulder. He is an expert in quantum optics, nanophotonics, and optical quantum information science. Dr. Sun obtained his BS in 2011 from Zhejiang University, China, and obtained his PhD in 2016 from the University of Maryland, College park. During his PhD, he developed the first spin-photon quantum switch and the first single-photon transistor using a solid-state spin. His pioneering research achievements have been awarded by the Maiman grand prize from the Optical Society of America and the Distinguished Dissertation Award from the University of Maryland, College Park. Before joining the faculty of JILA and the University of Colorado Boulder in 2020, Dr. Sun was a postdoctoral fellow (2017 – 2019) and a physical science research scientist (2019 – 2020) in the Ginzton Lab of Stanford University. There he worked with Prof. Jelena Vuckovic on color center based quantum optics and inverse designed quantum photonics. Dr. Sun has published more than 20 journal articles and book chapters. He is an assistant topical editor of JOSA B, and a regular reviewer of 19 journals including Nature, Nature Nanotechnology, Nature Physics and PRL. 孙硕目前任职于科罗拉多大学博尔德分校，担任物理系助理教授以及 JILA Associate Fellow. 他是量子光学，纳米光子学，以及光量子信息领域的杰出研究者。孙硕于 2011 年取得浙江大学光电信息工程系学士学位， 2016 年于马里兰大学帕克分校取得电子工程博士学位。在就读博士期间，他开发了首个基于固态电子自旋的光量子开关以及单光子调控的光学放大器。他的研究获得了美国光学学会颁发的 Maiman 学生论文奖以及马里兰大学电子工程系的杰出毕业论文奖。在加入科罗拉多大学之前，孙硕在斯坦福大学 Ginzton Lab 先后担任博士后（ 2017-2019 ）和研究科学家（ 2019-2020 ）职位。在斯坦福大学期间，他在 Jelena Vuckovic 研究组研究基于色心的量子光学以及基于目标优先设计的量子光学器件。孙硕博士迄今已发表论文和书刊章节超过 20 篇。他目前是美国光学学会期刊 JOSA B 的助理编辑，同时是包括 Nature, Nature Nanotechnology, Nature Physics, PRL 在内的 19 个期刊的审稿人。 报告 2 High-efficiency Electromagnetic Wave Manipulations with Metasurfaces 超构表面高效率调控电磁波 Shulin Sun 孙树林 Fudan University 复旦大学 Abstract Manipulating electromagnetic (EM) waves in desired manners are important for both sciences and applications. However, naturally existing materials exhibit limited capabilities on EM wave controls. Metamaterials, man-made materials consisting of subwavelength microstructures (also called as meta-atoms) arranged in certain macroscopic orders, were recently proposed that can exhibit many fascinating wave-manipulation effects, including negative refraction, super lens, and optical cloaking. However, after decades of development, researches on bulky metamaterials face several challenges, such as complicated fabrication, increasing energy loss. In particular, one important freedom, i.e., the arrangement order of meta-atoms inside bulky metamaterials, was difficult to be fully exploited due to the structural complexity. Facing these challenges, our group proposed to design ultrathin metasurfaces (or two-dimensional version of metamaterials) to efficiently manipulate EM waves. Different from conventional bulky optical elements (including metamaterials) replying on the accumulation of propagating phases for wave manipulations, the metasurfaces can introduce abrupt change of EM phases and thus modulate the imping light, which can be usually ultra-thin, low-loss, and easy for optical integration. The freedoms to manipulate EM waves are also significantly expanded with such two-dimensional systems. Here, I will focus on our works on high-efficiency EM wave controls, including surface wave manipulations and spin-dependent wave manipulations. 自由调控电磁波对于基础科学和实际应用均具有重要意义，然而自然材料对电磁波的调控能力受到极大限制。超构材料是一种由亚波长微结构（或称人工原子）按照某种宏观排列方式组成的 “ 人工材料 ” ，它对电磁波展现出众多新奇的调控效应，包括负折射、超透镜、光学隐身等。然而，经过数十年发展，超构材料领域的相关研究面临巨大的挑战，例如制备难、损耗高等。特别是三维超构材料的结构复杂性导致其排列方式这一重要自由度难以被充分利用。面对这些挑战，我们团队提出了利用超构表面高效率调控电磁波的新概念。不同于体式光学器件（包括超构材料）依赖传输相位积累调控电磁波的思想，超构表面是通过引入界面相位突变来调控入射波，具有体系薄、损耗低、易于光学集成等优势。基于这类两维体系，调控电磁波的自由度可被极大拓展。本次报告将主要介绍本团队在高效率表面波调控方面的工作，包括表面波调控和自旋依赖电磁调控等。 Biography Shulin Sun received his Ph. D. degree in Physics at Fudan University in 2009. From 2010 to 2013, he was a Postdoctoral Fellow of the Physics Division of National Center for Theoretical Sciences (NCTS) at National Taiwan University. In 2013, he joined the Department of Optical Science Engineering at Fudan University, and has been a full Professor and associate head of the department since 2019. He has been in the research fields of metamaterials/metasurfaces, plasmonics and photonic crystals, and published over 60 papers in scientific journals including Nature Materials, Nano Letters, Advances in Optics and Photonics, Light: Science and Applications, etc. The total citation is over 4800 times with the highest one being over 1200 times (google scholar). He won the Second Prize of National Natural Science Award in 2019 (ranked No. 2), the First Prize of Shanghai Natural Science Award in 2016 (ranked No. 2), the Prize of Important Optical Achievements of China in 2012 (ranked No. 1), and Outstanding Paper Award of Light: Science and Applications in 2018 (Corresponding Author). 孙树林， 2009 年在复旦大学物理学系获得博士学位， 2010 至 2013 年在台湾大学物理系任博士后研究员， 2013 年入职复旦大学光科学与工程系， 2019 年起任研究员、系副主任。研究方向包括电磁超构材料 / 超构表面、纳米光子学、光学微腔等，目前已发表论文 60 余篇，包括 Nature Materials, Nano Letters, Advances in Optics and Photonics, Light: Science Applications 等期刊论文，被引用 4800 余次，单篇最高引用 1200 余次（谷歌索引）。曾获 “2019 国家自然科学二等奖 ” （第二完成人）， “2016 上海市自然科学一等奖 ” （第二完成人）， “2012 中国光学重要成果奖 ” （第一完成人）， “2018 Light: Science Applications 杰出论文奖 ” （通讯作者）等奖项。 报告 3 Opto-Thermo-Electrohydrodynamic Tweezers: A New Tool for Biology andMedicine 光 - 热 - 电流体力学镊子：生物和医学的新工具 Justus Ndukaife Vanderbilt University, USA 美国范德堡大学 Abstract One-half of the 2018 Nobel Prize in Physics was awarded for Optical Tweezers and their application in biological systems. Optical tweezers have emerged as a powerful tool for the non-invasive trapping and manipulation of colloidal particles and biological cells. However, the stable trapping of nanometer-scale biological objects such as proteins, DNA, exosomes, and virions has been met with challenges due to the diffraction limit of light. Attempts to substantially increase the laser power to generate enough optical trapping potential for trapping such small biological objects, unfortunately, results in photo-toxicity and thermal stress, which damages the integrity of the biological specimens. An optical nanotweezer approach that can stably trap nanoscale biological objects without exposing them to high light intensity or heat which may physically alter or destroy detectable bio-activity is of paramount importance for fundamental life science research and translational biomedical applications. In this talk, I will introduce a new kind of optically controlled nanotweezers termed Opto-ThermoElectrohydrodynamic Tweezers (OTET) that enables the stable trapping and dynamic manipulation of sub-10 nm biomolecules at locations that are several microns away from the high-intensity laser focus, where they experience both negligible photothermal heating and light intensity. The OTET platform employs a finite array of plasmonic nanoholes illuminated with light in conjunction with an applied alternating current electric field to create the spatially varying electrohydrodynamic potential that can rapidly trap sub-10 nm biomolecules at femtomolar concentrations on-demand. This novel noninvasive optical nanotweezer is expected to open new horizons in life science and medicine by offering an unprecedented level of control of tiny nano-sized biological objects in solution without photo-induced damage. 2018 年的诺贝尔物理学奖，有一半授予了光镊及其在生物系统中的应用。目前，光镊已经成为非侵入式捕获和操纵胶体颗粒以及生物细胞的强有力工具。然而，由于光的衍射极限，蛋白质、 DNA 、外来体和病毒颗粒等纳米尺度生物目标的稳定捕获一直面临着困难。虽然通过大幅增强激光能量，可以产生更强的捕获能力，但这样却会引发光毒性和热应力，从而破坏生物标本的完整性。因此，我们亟需一种可以稳定捕获纳米尺度生物样本，而不将其暴露在可能破坏生物活性的高光强或高温下的纳米光镊方法。在本报告中，我将介绍一种新的纳米光镊，即光 - 热 - 电流体力学镊子（ OTET ），它能够稳定地捕获和动态操纵小于 10 纳米的生物分子，这些生物分子被放置于离高强度激光焦点几微米以外的地方，因此光热效应和光强对生物活性的影响可以忽略不计。 OTET 平台采用有限的等离激元纳米孔阵列，在光和外加交流电场的作用下，产生空间变化的电流体动力学势，可根据需要快速捕获小于 10 纳米的生物分子。这种新型的非侵入性纳米光镊可以在不引起光致损伤的情况下为微小纳米生物体提供前所未有的控制水平，有望在生命科学和医学领域开辟新的天地。 Biography Justus Ndukaife is an assistant professor of electrical engineering at Vanderbilt University, USA. He received a Ph.D. in Electrical Engineering from Purdue University, USA in 2017. Ndukaife’s interdisciplinary research is focused on nanophotonics for biomedical applications. He has made major contributions to the field optical nanotweezers. Very recently, Ndukaife invented a new optical nanotweezer approach termed: “opto-thermoelectrohydrodynamic tweezer (OTET)” that enables the trapping of sub-10 nm size biological molecules at tunable trapping locations several microns away from the highintensity focus to prevent the issue of photo-induced damage usually encountered when trying to trap such minuscule objects using the conventional optical tweezer technology that was recognized with one-half of the 2018 Physics Nobel Prize. Ndukaife’s research works have been published in the top peer-reviewed journals including Nature Nanotechnology, Science, ACS Nano, and Nano Letters, and he is an inventor of six technologies relating to optical nanotweezers. In recognition of his scientific contributions, Ndukaife received the Year 2017 Prize in Physics by the Dimitris N. Chorafas Foundation. His other honors include the Purdue College of Engineering Outstanding Research Award, NSBE Golden Torch Award, Best Paper Award at the ASME conference, Carnegie African Diaspora Fellowship Award, and Vanderbilt Provost Research Studios Award. Justus Ndukaife 于 2017 年获得美国普渡大学电气工程博士学位，现任美国范德堡大学电气工程系的助理教授。 Ndukaife 的研究横跨多个学科，主要集中在具有生物医学应用的纳米光子学上。他在纳米光镊领域做出了重要贡献。我们都知道，传统的光镊技术已经在 2018 年赢得了诺奖，但是其未能解决使用高强度激光对生物分子的损伤问题。最近， Ndukaife 发明了一种新的纳米光镊方法，称为 “ 光 - 热 - 电流体力学镊子（ OTET ） ” ，它能够在距离高强度激光焦点几微米外的位置捕获或操控小于 10 纳米的生物分子，因此可以防止光致损伤问题。 Ndukaife 的研究成果在包括 Nature Nanotechnology 、 Science 、 ACS Nano 和 Nano Letters 在内的顶级期刊上发表，同时，他是纳米光镊相关的六项技术的发明人。 Ndukaife 因其科学贡献获得了 Dimitris N. Chorafas 基金会颁发的 2017 年物理学奖。同时，他还荣获包括普渡工程学院杰出研究奖、 NSBE 金火炬奖、 ASME 会议最佳论文奖、卡内基非洲侨民奖学金和范德堡教务长研究工作室奖。 报告 4 Metasurfaces With Low-Dimensional Nanomaterials: Integration and Structuring 当超构表面遇到低维纳米材料：集成与结构化 Guangwei Hu 胡光维 National University of Singapore 新加坡国立大学 Abstract “God made the bulk; surfaces were invented by the devil.” Quoted from Wolfgang Pauli. In last two decades, two kinds of surfaces, i.e. metasurfaces (“2D metamaterials”) and low-dimensional nanomaterials (2D materials), emerge and support the extreme manipulation of light within an ultrathin and highly compact platform. However, the development of metasurface reaches a stage where all conventional materials (dielectrics, metals etc) have nearly been exhausted. While 2D nanomaterials presents exotic properties, they are too thin to be practically useful (Chemical Reviews, 2020). In this talk, I will show you how we can develop advanced metaphotonics by combining those two “devil-invented” surfaces, via our proposed two important strategies: integration and structuring. Specifically, I will provide a case study of integrating a monolayer semiconductor with a linear metasurface to develop the coherent nonlinear and valleytronic devices (Nature photonics, 2019), which are allowed by either metasurfaces or 2D materials alone. Besides, through structuring low-dimensional nanomaterials with a twisted stack, we achieved extreme dispersion engineering and “magic-angle” topological transitions of plasmon (Nano Letters, 2020) and phonon polaritons (Nature, 2020; Nature Communications, 2020). This work, for the first time, has transformed the so-called twistronics (i.e. engineering electron’s bandstructures of interlayer-coupled twisted 2D materials in condensed matter physics) into photonic regime and developed the new field of “opto-twistronics”. Via the proposed systematic strategies of integration and structuring, the advanced valleytronic, nonlinear, polaritonic and opto-twistronic applications may be developed. “ 上帝创造了体，但是表面却是由魔鬼发明的 ” （语自：沃尔夫冈 · 泡利）。过去二十年间，有两种 “ 表面 ” 材料兴起，分别是超构表面和二维材料，他们可以被制成超薄超集成器件并对电磁波实现极端操控。然而，超构表面领域几乎已经探索了所有可能的传统材料，包括金属和介质等。同时，二维材料尽管有各种新奇光电性能，但是由于太薄而无法在光波段被有效利用。这里，我将提出使用集成与结构化的两个策略，将这两种 “ 魔鬼般 ” 的表面材料结合，发展出新的超构光子学。具体来说，我将展示将线性超构表面和二维半导体集成，实现非线性和能谷器件。同时，将低维材料结构化或加以旋转，我们首次实现了低维材料等离子和声子极化激元的极端传播与拓扑调控；这一发现将凝聚态物理中兴起的 “ 转角电子学 ” 发展到光学领域。所提出的集成和结构化这两种系统的方法，有望助力新的能谷学，非线性光学，极化激元和 “ 转角光子学 ” 的发展和应用。 Biography Mr. Guangwei Hu was born in 1994. He received the B. Sc. in Harbin Institute of Technologies in 2016 and is the PhD student in National University of Singapore from Sept. 2016 to Oct. 2020. His current research interests include fundamental light-matter interactions of metasurface and low-dimensional nanomaterials, with promising applications, such as the multifunctional metadevices, the optical engineering of the 2D materials, polaritonics (plasmon, phonon and excitons), and topological transitions in photonics, among many others. He has co-authored more than 20 papers in many journals including Nature, Nature Photonics, Light: Science Applications, Nature Communications, Science Advances, Chemical Reviews, Nano Letters, Advanced Materials, and more others. He received NUS Research Scholarships, President's Graduate Fellowships and Chinese government award for outstanding self-finance students abroad. 胡光维于 2016 年在哈尔滨工业大学获得本科学位， 2016 年 9 月至 2020 年 10 月于新加坡国立大学博士在读。其研究兴趣包括超构表面和低维材料中的光与物质基本相互作用，研发多功能超构器件，基于二维材料的光学工程，极化激元调控，拓扑光子学等。目前，已在 Nature, Nature Photonics, Light: Science Applications 等众多期刊发文约 20 余篇；并获得新加坡国立大学研究奖学金，校长奖学金和优秀自费留学生奖学金等。 报告 5 Synthetic dimensions in dynamic photonic structures: quantum and classical applications 动态光子结构中的合成维度：量子和经典应用 Avik Dutt Stanford University 斯坦福大学 Abstract Photons are incredibly versatile particles, with multiple degrees of freedom such as frequency, spatiotemporal mode structure, polarization and propagation direction, that can be manipulated by dynamic photonic structures. In this talk, I will show how to harness the manipulation of these degrees of freedom to create synthetic photonic dimensions, for quantum, nonlinear and topological photonics. For this purpose, we use high-quality-factor resonators to enhance light-matter interactions. Specifically, we show how synthetic frequency dimensions can be used to simulate a wide variety of physics related to the quantum Hall effect, such as effective magnetic fields, spin-orbit coupling, spin-momentum locking and topological chiral one-way edge modes. These two-dimensional effects are realized in a single modulated photonic resonator, elucidating how higher-dimensional physics can be implemented experimentally in much lower-dimensional structures. We introduce a method to directly detect the band structures in such synthetic dimensions from time-resolved transmission measurements. This paves the way for quantum simulation and information processing in high dimensions on chip using scalable devices with significantly reduced footprint. High-quality resonators can also be used for generating ultrabroadband frequency combs – a sequence of narrow equi-spaced lines in the spectral domain. We show how to generate two such combs on a single silicon nitride chip pumped by a single laser for real-time spectroscopy of materials. The same resonators pumped with much lower powers also generate nonclassical squeezed light, with a quantum noise reduction below the standard quantum limit. Using this technique, we report the first nanophotonic source of optical squeezing, which finds applications as a scalable source for quantum sensing and quantum information processing. At the end I will briefly discuss the potential for extensions to non-Hermitian systems, and to strongly interacting, time-modulated quantum systems. 光子是非常多功能的粒子，具有可由动态光子结构控制的多个自由度，包括频率、时空模式、偏振和传播方向等。在本报告中，我将展示如何通过操控这些自由度来产生量子、非线性和拓扑光子学中的合成光子维度。为此，我们使用高 Q 值的谐振器来增强光与物质的相互作用。特别的，我们展示了如何使用合成频率维度来模拟与量子霍尔效应有关的各种物理现象，如有效磁场、自旋轨道耦合、自旋动量锁定和拓扑手性单向边缘模式。这些二维效应是在单个调制光子谐振器中实现的，解释了如何在低维结构中用实验实现高维物理。报告中，我还介绍了一种通过时间分辨透射测量直接检测以上合成维度的能带结构的方法。这为在芯片上通过可扩展的设备和较少的步骤实现高维量子模拟和信息处理铺平了道路。 高质量的谐振器也可以用来产生超宽带频率梳（在频谱域上的窄带等间距线）。我们在报告中展示了如何在单个氮化硅芯片上用单激光泵浦产生两个超宽带频率梳，以用于材料的实时光谱分析。 如果我们用功率低得多的激光泵浦同样的谐振器，则可产生非经典的压缩光，其量子噪声可以降低至到标准量子极限以下。利用该技术，我们报道了首个压缩纳米光源，它有望成为量子传感和量子信息处理应用的可扩展光源。最后，我将简要讨论其扩展到非厄米系统和强相互作用、时间调制量子系统的可能性。 Biography Avik Dutt received the M.S. and Ph.D degrees in Electrical and Computer Engineering from Cornell University, Ithaca, NY, USA, in 2015 and 2017, respectively, and the Bachelor’s degree from Indian Institute of Technology (IIT), Kharagpur, in 2011. He is currently a postdoctoral scholar at Stanford University. His research interests span quantum/nonlinear photonics, silicon nanophotonics, topological physics, synthetic dimensions, frequency combs, and time-modulated/non-Hermitian systems. Avik was the Editor’s pick for the Outstanding Reviewer for July 2020 in LSA, and is among the Top 1% of Physics reviewers (2018). He was awarded a Jacobs Fellowship (2011) and a Zurich instruments thesis award for his Ph.D. dissertation (2017). He has authored/co-authored more than 30 journal articles in journals such as Science, Nature Communications, Nature Photonics, Light: Science and Applications, Science Advances, PRL, Optica and other OSA, APS, IEEE and ACS journals, which have been cited more than 1000 times since 2015. He was a subcommittee member of the Latin America Optics Photonics conference (2018) and a session chair for the SPIE Optics + Photonics conference (2020). Avik enjoys communicating science broadly by contributing to Wikipedia and news articles, especially involving projects which increase the representation of women and racial minorities, such as Art+Feminism. Avik Dutt 于 2011 年获得印度理工学院（ IIT ）的学士学位，并于 2015 年和 2017 年获得康奈尔大学的电子计算机工程专业的硕士和博士学位。目前，他是斯坦福大学的博士后。他的研究领域涉及量子 / 非线性光子学、硅纳米光子学、拓扑物理、合成维度、频率梳和时间调制 / 非厄米系统。 Avik 曾荣获 Light: Science Applications 2020 年 7 月编辑选择的杰出审稿人，也是 2018 年物理学排名前 1% 的审稿人之一。他曾获雅各布斯奖学金（ 2011 年）和苏黎世仪器论文奖（ 2017 年），并在 Science 、 Nature Communications 、 Nature Photonics 、 Light: Science and Applications 、 Science Advances 、 PRL 、 Optica 和其他 OSA 、 APS 、 IEEE 和 ACS 期刊上发表了 30 多篇文章，自 2015 年以来被引超过 1000 次。他是拉丁美洲光学和光子学会议（ 2018 年）的小组委员会成员和 SPIE 光学 + 光子学会议（ 2020 年）的分会主席。 Avik 喜欢通过在维基百科和新闻文章中发表文章来广泛传播科学，尤其是涉及到增加妇女和少数民族代表性的项目，如艺术 + 女权主义。 同时，本次讲座还邀请到威斯康星大学的 Mikhail Kats 教授为大家带来精彩的主持。 每一期 iCANX Talks 直播结束后，都深受参会者好评，不仅为感兴趣的参会者和读者深度理解相关技术提供了帮助，也为研究生深入开展科研提供了一个很好的平台。更多精彩，尽在 iCANX Talks ，扫描二维码，关注更多精彩内容吧！
Wi-fi on rays of light—100 times faster, and never overloaded March 17, 2017 Credit: Public Domain Slow wifi is a source of irritation that nearly everyone experiences. Wireless devices in the home consume ever more data, and it's only growing, and congesting the wi-fi network. Researchers at Eindhoven University of Technology have come up with a surprising solution: a wireless network based on harmless infrared rays. The capacity is not only huge (more than 40Gbit/s per ray) but also there is no need to share since every device gets its own ray of light. This was the subject for which TU/e researcher Joanne Oh received her PhD degree with the 'cum laude' distinction last week. The system conceived in Eindhoven is simple and, in principle, cheap to set up. The wireless data comes from a few central 'light antennas', for instance mounted on the ceiling, which are able to very precisely direct the rays of light supplied by an optical fiber. Since there are no moving parts, it is maintenance-free and needs no power: the antennas contain a pair of gratings that radiate light rays of different wavelengths at different angles ('passive diffraction gratings'). Changing the light wavelengths also changes the direction of the ray of light. Since a safe infrared wavelength is used that does not reach the vulnerable retina in your eye, this technique is harmless. No interference If you walk around as a user and your smartphone or tablet moves out of the light antenna's line of sight, then another light antenna takes over. The network tracks the precise location of every wireless device using its radio signal transmitted in the return direction. It is a simple matter to add devices: they are assigned different wavelengths by the same light antenna and so do not have to share capacity. Moreover, there is no longer any interference from a neighboring wi-fi network . Data capacity of light rays Current wi-fi uses radio signals with a frequency of 2.5 or 5 gigahertz. The system conceived at TU Eindhoven uses infrared light with wavelengths of 1500 nanometers and higher; this light has frequencies that are thousands of times higher, some 200 terahertz, which makes the data capacity of the light rays much larger. Joanne Oh even managed a speed of 42.8 Gbit/s over a distance of 2.5 meters. For comparison, the average connection speed in the Netherlands is two thousand times less ( 17.6 Mbit/s ). Even if you have the very best wi-fi system available, you won't get more than 300 Mbit/s in total, which is some hundred times less than the speed per ray of light achieved by the Eindhoven study. The Eindhoven system has so far used the light rays only to download; uploads are still done using radio signals since in most applications much less capacity is needed for uploading. Five years The work of doctoral student Oh is part of the wider BROWSE project headed up by professor of broadband communication technology Ton Koonen, and with funding from the European Research Council. Joanne Oh focused predominantly on the technology of data transmission via directable infrared light rays. Other PhDs are still working on the technology that tracks the location of all the wireless devices as well as on the essential central fiber-optic network connecting the light antennas. Koonen expects it will still be five years or more before the new technology will be in our stores. He thinks that the first devices to be connected to this new kind of wireless network will be high data consumers like video monitors, laptops or tablets. Many devices at the same time Koonen's group is not the only one working on 'indoor optical wireless networks'. A few other universities and research institutes around the world are also studying whether data can be transmitted via a room's LED lighting. However, the drawback here is that the bandwidth is not high and that the connected devices still have to share. A few other groups are investigating network concepts in which infrared light rays are directed using movable mirrors. The disadvantage here is that this requires active control of the mirrors and therefore energy, and each mirror is only capable of handling one ray of light at a time. The grating used by Koonen and Oh can cope with many rays of light and, therefore, devices at the same time. The work of Oh and Koonen comes under the auspices of the TU/e Institute for Photonic Integration, one of the world's leading research institutes for 'photonics', the use of light (photons) rather than electricity (electrons) to transmit data. Explore further: More efficient nano-LED opens door to faster microchips Provided by: Eindhoven University of Technology
F rontiers of Materials Science 2014 (3) 出刊 受编委委托，作为guest editor，与Guangling Song共同组织Spring旗下的《 F rontiers of Materials Science 》(SCI期刊) 2014年第3期- Light metals as biomaterials 专辑。 感谢崔福斋教授和潘劲松博士的大力协助， 作者们和审稿人 的全力支持，所有文章如期出刊。 本期 10篇稿件作者来自大陆（9篇）、台湾（1篇）；有综述2篇、研究论文8篇；有钛合金1篇、镁合金9篇。 特别记忆犹新的是，大 年30前 与国内 许多学者打电话和国际同行 发email，得到了许多朋友的积极响应。尽管后来情况有较大变化，我们经过努力总算完成了组稿和审稿任务。第一次切身感受到国际期刊主编工作的不容易，需要了解当前热点研究和国际同行的工作，需要与一线学者广交朋友。难怪 郑玉峰教授发出“ 做Guest Editor真的不容易 ”的感叹。 中国国际期刊面临与西方大型出版机构的合作与 竞争。 特别是在期刊知名度不高和稿源不足的情况下，中国国际期刊的崛起需要国内资深学者和海外华人学者的热心支持。通过多次与一些期刊人的交流，真正从内心对国内顶级期刊人的默默奉献和坚守表示钦佩。8月顺道拜访长沙某著名出版社，看到不少期刊人冒着酷暑仍坚守在岗位。 目录 ： Article Preface for the special issue on light metals as biomaterials Guang-Ling Song , Rong-Chang Zeng in Frontiers of Materials Science (2014) Download PDF (49 KB) Article Effect of different processings on mechanical property and corrosion behavior in simulated body fluid of Mg-Zn-Y-Nd alloy for cardiovascular stent application The biomagnesium alloys have been considered to be one of the most potential biodegradable metal materials due to its good mechanical compatibility, biological compatibility, biological security and biodegrada... Shi-Jie Zhu , Qian Liu , Ya-Feng Qian , Bin Sun , Li-Guo Wang … in Frontiers of Materials Science (2014) Look Inside Get Access Article Effect of corrosion on mechanical behaviors of Mg-Zn-Zr alloy in simulated body fluid The main purpose of this paper is to investigate the effect of corrosion on mechanical behaviors of the Mg-Zn-Zr alloy immersed in simulated body fluid (SBF) with different immersion times. The corrosion behav... Rong Song , De-Bao Liu , Yi-Chi Liu , Wen-Bo Zheng , Yue Zhao … in Frontiers of Materials Science (2014) Look Inside Get Access Article In vitro corrosion of Mg-6Zn-1Mn-4Sn-1.5Nd/0.5Y alloys The microstructure evaluation, surface morphology, chemical compositions and phase analysis of the biomedical Mg-6Zn-1Mn-4Sn-1.5Nd/0.5Y (ZMT614-1.5Nd/0.5Y) alloys were investigated by means of optical microsco... Rong-Chang Zeng , Lei Wang , Ding-Fei Zhang , Hong-Zhi Cui … in Frontiers of Materials Science (2014) Look Inside Get Access Article Degradation behaviors of surface modified magnesium alloy wires in different simulated physiological environments The degradation behaviors of the novel high-strength AZ31B magnesium alloy wires after surface modification using micro-arc-oxidization (MAO) and subsequently sealing with poly-L-lactic acid (PLLA) in differen... Xuan Li , Chao Shi , Jing Bai , Chao Guo , Feng Xue … in Frontiers of Materials Science (2014) Look Inside Get Access Article Designation and development of biomedical Ti alloys with finer biomechanical compatibility in long-term surgical implants Developing the new titanium alloys with excellent biomechanical compatibility has been an important research direction of surgical implants materials. Present paper summarizes the international researches and ... Zhen-Tao Yu , Ming-Hua Zhang , Yu-Xing Tian , Jun Cheng … in Frontiers of Materials Science (2014) Look Inside Get Access Article Biocorrosion resistance of coated magnesium alloy by microarc oxidation in electrolyte containing zirconium and calcium salts The key to use magnesium alloys as suitable biodegradable implants is how to adjust their degradation rates. We report a strategy to prepare biocompatible ceramic coating with improved biocorrosion resistance ... Ya-Ming Wang , Jun-Wei Guo , Yun-Feng Wu , Yan Liu … in Frontiers of Materials Science (2014) Look Inside Get Access Article Magnesium based degradable biomaterials: A review Magnesium has been suggested as a revolutionary biodegradable metal for biomedical applications. The corrosion of magnesium, however, is too rapid to match the rates of tissue healing and, additionally, exhibi... Xue-Nan Gu , Shuang-Shuang Li , Xiao-Ming Li , Yu-Bo Fan in Frontiers of Materials Science (2014) Look Inside Get Access Article Effect of annealing temperature on the microstructure and mechanical properties of an as-rolled Mg-9wt.%Li-3wt.%Al-1wt.%Zn alloy sheet This study investigated the effect of annealing temperature on the mechanical properties of an as-rolled Mg-9.26wt.%Li-3.03wt.%Al-1.10wt.%Zn (LAZ931) alloy sheet. The dual-phase (α + β) LAZ931 alloy plate of 3... Meng-Chang Lin , Shang-Qiu Lin , Jun-Yen Uan in Frontiers of Materials Science (2014) Look Inside Get Access Article One-step electrochemical fabrication of bilayered MgO/polymer coating on magnesium alloy This research demonstrates a novel one-step electrochemical method to fabricate thick bilayer coatings on magnesium alloy in acid phosphate electrolyte containing aniline monomer and styrene-acrylic emulsion (... Jun Liang , Ren-Hui Zhang , Zhen-Jun Peng , Bai-Xing Liu in Frontiers of Materials Science (2014) Look Inside Get Access Article Synergistic effect of chloride ion and albumin on the corrosion of pure magnesium In this work, we report on synergistic effect of chloride ion and albumin on the corrosion of pure magnesiumthrough corrosion tests. We show that the adsorption of albumin mainly affects the anodic polarizatio... Cheng-Long Liu , Yi Zhang , Chun-Yan Zhang , Wei Wang … in Frontiers of Materials Science (2014) Look Inside Get Access
Genesis -------------------------------------------------------------------------- The Beginning 1 In the beginning, God created the heavens and the earth. 2 The earth didn’t have any shape. And it was empty. Darkness was over the surface of the ocean. At that time, the ocean covered the earth. The spirit of God was hovering over the waters. 3 God said, “Let there be light.”And there was light. 4 God saw the light was good, He separated the light from darkness. 5 God called the light “day.” He called the darkness” night.” There was evening, and there was morning. It was day one. Holy Bible New international reader’s version 有光 纵贯线 作曲：周华健 作词：李宗盛 编曲 / 监制：纵贯线 我明白你的从容 是知命也是真勇 生命破绽自己缝 笑对命运的捉弄 你点醒我 刹那我懂 服了你 不急不窘 如常人向西向东 你要的不是人哄 你不求谁人来宠 其实你每步都重 有光 在你心田里播种 解释了你的遭遇为何不同 有光 点亮你灵性天空 有一对清亮双瞳 看见了爱 感恩 感动 转载来自 ※ Mojim.com 魔镜歌词网 要无怨才能想通 这人生你比我懂 是的谁没有苦痛 比起你怎么说痛 你不过 渴望普通 有光 在你心田里播种 解释了你的遭遇为何不同 有光 点亮你灵性天空 有一对清亮双瞳 看见了爱 因为 有光 在你心田里播种 解释了你的遭遇为何不同 有光 点亮你灵性天空 有一对清亮双瞳 看见了爱 感恩 感动
Have you beenfrustrated that you took the photo with wrong focus and what you meant to see is not very clear in the picture? Now you won't have that problem anymore, since the Lytro Inc have created a new kind of camera, light-field camera, you can capture the scene first, and then refocus it! It's a total new experience and has been called the first revolution of cameras since 1800s! A light-field camera, also called aplenoptic camera, is a camera that used a microlens array to capture4D light field(color, intensity and vector direction of the rays of light) information about a scene. Such light field information can be used to improve the solution of computer graphics and vision-related problems . The light field is a core concept in imaging science, representing fundamentally more powerful data than in regular photographs . The applications of light fields conclude all uses of computational imaging in art, science, engineering, and medicine. For instance, Light Field Rendering , Synthetic Aperture Photography and 3D Display . Perhaps in the future, it will play a important role in Remote Sensing Photogrammetry ! References: Light-field camera in Wikipedia. http://en.wikipedia.org/wiki/Light-field_camera Science Inside | Lytro. http://www.lytro.com/science_inside Light field in Wikipedia. http://en.wikipedia.org/wiki/Light_field Lytro in Wikipedia. http://en.wikipedia.org/wiki/Lytro
I enjoyed everything about my first visit to Seattle after 11 years, except for the mess at the Sea-Tac airport. So, I was determined to take the Link Light Rail from downtown to Sea-Tac at the end of my visit. (I was also told by a friend that rental car picked up at the airport is usually more expensive, another reason to take a public transportation to the Sea-Tac.) Finding the entrance to the Light Rail was not easy, because it is not marked. Most people would start the trip by taking a bus to the "bus tunnel," from where it's easy to get to the Light Rail. When we finally found the entrance (next to the Nordstrom store), the adventure continued... First, I didn't read every small sign on the way down to the platform. I just wanted to get there. I didn't even bother to use the elevator at the end, just carried my luggage and walked downstairs. When I got there, I didn't know what the Light Rail looked like, and asked a guy in uniform. He said this is where you get on the rail. I looked around and didn't see how I could get a ticket. So, I was sent back upstairs; this time, I used the elevator. Someone helped me to start the conversation with the ticket machine, and the rest was easy. A one-way ticket costs $2.75, and can be purchased using a credit card. No one was there to check the ticket, and we all got on the rail. I was curious about the system, and started to look around. There were some handouts, one of which says "A fine of USD 124" for not having the ticket (or not using the pre-paid card correctly). I wondered if anyone would dare to get on a cheap rail and risk the fine of USD 124. Midway, two guys in uniform showed up to check tickets. To my surprise, two people were "caught" without proper "tickets." One looked like a foreigner (non-Asian), who held dollar bills in her hand. She was lectured, but not fined. The other looked like a student in college. He was told that he didn't initiate the pre-paid card properly, and was put into the city data base for the record. Both were NOT fined. Clearly, the system is still new, and the fine will not come any time soon. The goal is to educate people! Link to the SoundTransit in Seattle: http://www.soundtransit.org/Rider-Guide/Link-light-rail.xml
The software on Monte Carlo simulation of light transport in 3-D voxelized media is released (called MCVM). By using MCVM, researchers can obtain both steady-state and time-resolved light transport properties in biological tissue with realistic shape and structure. MCVM is fully documented, including its article and instructions. we also provide its application examples on visible Chinese human and digital rat. The source code of MCVM is open. Anyone can download this software in free but please cite our article: Ting Li, Hui Gong,Qingming Luo, MCVM: Monte Carlo modeling of photon migration in voxelized media, Journal of Innovative Optical Health Sciences, 3(2): 91-102, 2010. Download: http://cn.ziddu.com/dl.php?trackid=5346url=/download/499457/MCVM_upload1.rar.html http://freakshare.net/files/aeo0e506/MCVM_upload1.rar.html http://hotfile.com/dl/50108813/e02c679/MCVM_upload1.rar.html Download (Added three application examples): http://cn.ziddu.com/dl.php?trackid=4420url=/download/499458/MCVM_upload2.rar.html http://hotfile.com/dl/50109186/6872bb0/MCVM_upload2.rar.html
标签: Light
