中央研究院 原子與分子科學研究所
研究成果
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陳貴賢 博士Nature Commmunictions 11, 4233 (2020).Nonnoble metal catalysts are low-cost alternatives to Pt for the oxygen reduction reactions (ORRs), which have been studied for various applications in electrocatalytic systems. Among them, transition metal complexes, characterized by a redox-active single-metal-atom with biomimetic ligands, such as pyrolyzed cobalt–nitrogen–carbon (Co–N x /C), have attracted considerable attention. Therefore, we reported the ORR mechanism of pyrolyzed Vitamin B12 using operando X-ray absorption spectroscopy coupled with electrochemical impedance spectroscopy, which enables operando monitoring of the oxygen binding site on the metal center. material design strategies for high-performance electrocatalysts for fuel cell applications. Furthermore, the charge transfer mechanism between the catalyst and reactant enables further Co–O species ...
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郭哲來 博士Angewandte Chemie International Edition, https://doi.org/10.1002/anie.202012665 (2020).Experimental infrared spectra between 2600 to 3800 cm-1 for a series of asymmetric proton bound dimers with protonated trimethylamine (TMA–H+) as the proton donor were recorded and analyzed. Based on conventional wisdom, the frequency of the N-H+ stretching mode is expected to red shift as the proton affinity of proton acceptors (Ar, N2, CO, C2H2, H2O, CH3OH, and C2H5OH) increases. The observed band, however, shows a peculiar splitting of ≈300 cm-1 with the intensity shifting pattern resembling a two-level system. Theoretical investigation based on ab initio anharmonic algorithms reveals that the observed band splitting and its extraordinarily large gap of ≈300 cm-1 is a result of strong coupling betw ...
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謝雅萍 博士Nature Communications, 12:6291 (2021).We here report on the direct observation of ferroelectric properties of water ice in its 2D phase. Upon nanoelectromechanical confinement between two graphene layers, water forms a 2D ice phase at room temperature that exhibits a strong and permanent dipole which depends on the previously applied field, representing clear evidence for ferroelectric ordering. Characterization of this permanent polarization with respect to varying water partial pressure and temperature reveals the importance of forming a monolayer of 2D ice for ferroelectric ordering which agrees with ab-initio and molecular dynamics simulations conducted. The observed robust ferroelectric properties of 2D ice enable novel nanoelectromechanical devices that exhibit memristive properties. A unique bipolar mechanical switching behavior is observed where previous charging history contro ...
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賴品光 博士Nature Protocols. doi: 10.1038/s41596-021-00564-8 (2021).The dynamics of DNA double-strand break (DSB) repairs including homology-directed repair and nonhomologous end joining play an important role in diseases and therapies. However, investigating DSB repair is typically a low-throughput and cross-sectional process, requiring disruption of cells and organisms for subsequent nuclease-, sequencing- or reporter-based assays. In this protocol, we provide instructions for establishing a bioluminescent repair reporter system using engineered Gaussia and Vargula luciferases for noninvasive tracking of homology-directed repair and nonhomologous end joining, respectively, induced by SceI meganuclease, SpCas9 or SpCas9 D10A nickase-mediated editing. We also describe complementation with orthogonal DSB repair assays and omics analyses to validate the reporter readouts. The bioluminescent repair reporter system pro ...
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郭哲來 博士The Journal of Physical Chemistry Letters 11, 10067 (2020); https://doi.org/10.1021/acs.jpclett.0c03059.Complex vibrational features of solvated hydronium ion, H3O+, in 3 μm enable us to look into the vibrational coupling among O-H stretching modes and other degrees of freedom. Two anharmonic coupling schemes have often been engaged to explain observed spectra: coupling with OH bending overtone, known as Fermi resonance (FR), has been proposed to account for the splitting of the OH stretch band at ~3300 cm-1 in H3O+…Ar3, but an additional peak in H3O+…(N2)3 at the similar frequency region has been assigned to a combination band (CB) with the low-frequency intermolecular stretches. While even stronger vibrational coupling is expected in H3O+…(H2O)3, such pronounced peaks are a ...
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任祥華 博士Nature Communications 13, 4598 (2022).Explorations of symmetry and topology have led to important breakthroughs in quantum optics, but much richer behaviors arise from the non-Hermitian nature of light-matter interactions. A high-reflectivity, non-Hermitian optical mirror can be realized by a two-dimensional subwavelength array of neutral atoms near the cooperative resonance associated with the collective dipole modes. Here we show that exceptional points develop from a nondefective degeneracy by lowering the crystal symmetry of a square atomic lattice, and dispersive bulk Fermi arcs that originate from exceptional points are truncated by the light cone. From its nontrivial energy spectra topology, we demonstrate that the geometry-dependent non-Hermitian skin effect emerges in a ribbon geometry. Furthermore, skin modes localized at a boundary show a scale-free behavior that stems from ...
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陳貴賢 博士Nano Energy, 93, 106809 (2022).Employing direct Z-scheme semiconductor heterostructures in photocatalysis offers efficient charge carrier separation and isolation of both redox reactions, thus beneficial to reduce CO2 into solar fuels. Here, a ZnS/ZnIn2S4 heterostructure, comprising cubic ZnS nanocrystals on hexagonal ZnIn2S4 (ZIS) nanosheets, is successfully fabricated in a single-pot hydrothermal approach. The composite ZnS/ZnIn2S4 exhibits microstrain at its interface with an electric field favorable for Z-scheme. At an optimum ratio of Zn:In (~ 1:0.5), an excellent photochemical quantum efficiency of around 0.8% is reached, nearly 200-fold boost compared with pristine ZnS. Electronic levels and band alignments are deduced from ultraviolet photoemission spectroscopy and UV-Vis. Evidence of the direct ...
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賴品光 博士Advanced Materials. https://doi.org/10.1002/adma.202208966 (2023).Our latest publication employed PalmGRET, a bioluminescence-resonance-energy-transfer (BRET)-based EV reporter, to discover an abundant release of big EVs (bEVs; >200 nm) by aggressive breast cancers when compared to epithelial and less malignant cells. bEVs have been largely overshadowed by small EVs (sEVs; <200 nm) in EV research in the past decades. This is the first study to accurately detect and systematically compare biophysical property and in vivo profiles of breast cancer bEVs and sEVs. This is followed by the identification of EV surface oncoproteins, and their role in modulating organotropism and tumorigenic potential of the bEVs and sEVs. Our landmark findings impart a broad and deep reference for upcoming EV studies, with an emphasis on EV engineering for diagnosis and therapeutic applications.
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許良彥 博士Journal of Physical Chemistry Letters, 14, 9, 2395–2401 (2023).The Huang–Rhys (HR) factor, a dimensionless factor that characterizes electron–phonon (vibronic) coupling, has been extensively employed to investigate a variety of material properties. In the same spirit, we propose a quantity called the polaritonic HR factor to quantitatively describe the effects of (i) light–matter coupling induced by permanent dipoles and (ii) dipole self-energy. The former leads to polaritonic displacements, while the latter is associated with the electronic coupling shift named reorganization dipole self-coupling. In the framework of macroscopic quantum electrodynamics, our theory can evaluate the polaritonic HR factor, reorganization dipole self-coupling, and modified light–matter coupling strength in an arbitrary dielectric environment without free parameters, whose magnitudes are in good agreement w ...
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許良彥 博士Journal of Physical Chemistry Letters, 13, 9695–9702 (2022).Richard Feynman stated that “The theory behind chemistry is quantum electrodynamics”. However, harnessing quantum-electrodynamic (QED) effects to modify chemical reactions is a grand challenge and currently has only been reported in experiments using cavities due to the limitation of strong light–matter coupling. In this article, we demonstrate that QED effects can significantly enhance the rate of electron transfer (ET) by several orders of magnitude in the absence of cavities, which is implicitly supported by experimental reports. To understand how cavity-free QED effects are involved in ET reactions, we incorporate the effect of infinite one-photon states into Marcus theory, derive an explicit expression for the rate of radiative ET, and develop the concept of “electron transfer overlap”. Moreover, QED effects may l ...
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張煥正 博士ACS Appl. Mater. Interfaces 12, 3847−3853 (2020).Fluorescent nanodiamond (FND) containing nitrogen-vacancy (NV) centers as built-in fluorophores exhibits a nearly constant emission profile over 550 – 750 nm upon excitation by vacuum-ultraviolet (VUV), extreme ultraviolet (EUV), and X- radiations from a synchrotron source over the energy (wavelength) range of 6.2 – 1450 eV (0.86 – 200 nm). The photoluminescence (PL) quantum yield of FND increases steadily with the increasing excitation energy, attaining a value as great as 1700% at 700 eV (1.77 nm). Notably, the yield curve is continuous, having no gap in the VUV to X-ray region. In addition, no significant PL intensity decreases were observed for hours. Applying the FND sensor to measure the absorption cross sections of gaseous O2 over 110 – 200 nm and comparing the measurements with ...
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羅佩凌 博士Analytical Chemistry, 94, 5752 (2022).A novel spectrometer has been developed based on synchronized two-color time-resolved dual-comb spectroscopy (TRDCS), enabling high-resolution hyperspectral measurements. The proposed approach with TRDCS exhibits great potential in quantitative diagnostics of multispecies and opens opportunities to decipher key reaction mechanisms in atmospheric chemistry. In this work, we perform simultaneous measurements in two distinct molecular fingerprint regions near 2.9 and 7.8 μm by employing the new approach with synchronized two-color TRDCS. Upon flash photolysis of CH2I2/O2/N2 gas mixtures, multiple reaction species, involving the simplest Criegee intermediates (CH2OO), formaldehyde (CH2O), hydroxyl (OH) and hydroperoxy (HO2) radicals are simultaneously detected with mic ...
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詹楊皓 博士Proceedings of National Academy of Sciences, 118 (25) e1906938118 (2021).Shift current is a direct current generated from nonlinear light–matter interaction in a noncentrosymmetric crystal and is considered a promising candidate for next-generation photovoltaic devices. The mechanism for shift currents in real materials is, however, still not well understood, especially if electron–hole interactions are included. Here, we employ a first-principles interacting Green’s-function approach on the Keldysh contour with real-time propagation to study photocurrents generated by nonlinear optical processes under continuous wave illumination in real materials. We demonstrate a strong direct current shift current at subbandgap excitation frequencies in monolayer GeS due to strongly bound excitons, as well as a giant excitonic enhancement in the shift current coefficients at above bandgap photon frequencies. Our re ...
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汪治平 博士Nature Communication 11, 2787 (2020)Availability of relativistically intense, single-cycle, tunable infrared sources will open up newareas of relativistic nonlinear optics of plasmas, impulse IR spectroscopy and pump-probeexperiments in the molecular fingerprint region. However, generation of such pulses is still achallenge by current methods. Recently, it has been proposed that time dependent refractiveindex associated with laser-produced nonlinear wakes in a suitably designed plasma densitystructure rapidly frequency down-converts photons. The longest wavelength photons slipbackwards relative to the evolving laser pulse to form a single-cycle pulse within the nearlyevacuated wake cavity. This process is called photon deceleration. Here, we demonstrate thisscheme for generating high-power (~100 GW), near single-cycle, wavelength tunable(3–20 μm), infrared pulses using an 81 ...
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謝雅萍 博士Nano Lett., https://doi.org/10.1021/acs.nanolett.1c02331 (2021).We here demonstrate the multifunctional properties of atomically thin heterojunctions that are enabled by strong interfacial interactions and their integration into ultra-high performance, self-powered sensors. Epitaxial alignment between tin diselenide and graphene through direct growth produces thermoelectric and mechanoelectric properties beyond the ability of either component. An unprecedented ZT of 2.43 originated from the synergistic combination of graphene’s high carrier conductivity and SnSe2 mediated thermal conductivity lowering. Moreover, strong interaction at the SnSe2/graphene interface produces stress localization that results in a novel 2D-crack-assisted strain sensing mechanism whose sensitivity (GF=450) is superior to all other 2D materials. Finally, the graphene-assisted growth process, permits the formation of hi ...
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余慈顏 博士Nature Communications, 13, 1513 (2022).Limited methods are available for investigating the reorientational dynamics of A-site cations in two-dimensional organic–inorganic hybrid perovskites (2D OIHPs), which play a pivotal role in determining their physical properties. Here, we describe an approach to study the dynamics of A-site cations using solid-state NMR and stable isotope labelling. 2H NMR of 2D OIHPs incorporating methyl-d3-ammonium cations (d3-MA) reveals the existence of multiple modes of reorientational motions of MA. Rotational-echo double resonance (REDOR) NMR of 2D OIHPs incorporating 15N- and 13C-labeled methylammonium cations (13C,15N-MA) reflects the averaged dipolar coupling between the C and N nuclei undergoing different modes of motions. Our study reveals the interplay between the A-si ...
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謝佳龍 博士ACS Nano, 16(2): 2774-2788 (2022).Chromatin is a DNA–protein complex that is densely packed in the cell nucleus. The nanoscale chromatin compaction plays critical roles in the modulation of cell nuclear processes. However, little is known about the spatiotemporal dynamics of chromatin compaction states because it remains difficult to quantitatively measure the chromatin compaction level in live cells. Here, we demonstrate a strategy, referenced as DYNAMICS imaging, for mapping chromatin organization in live cell nuclei by analyzing the dynamic scattering signal of molecular fluctuations. Highly sensitive optical interference microscopy, coherent brightfield (COBRI) microscopy, is implemented to detect the linear scattering of unlabeled chromatin at a high speed. A theoretical model is established to determine the local chromatin density from the statistical fluctuation of the ...
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王偉華 博士Nano Lett., 22, 6, 2270–2276 (2022).Understanding the Coulomb interactions between two-dimensional (2D) materials and adjacent ions/impurities is essential to realizing 2D material-based hybrid devices. Electrostatic gating via ionic liquids (ILs) has been employed to study the properties of 2D materials. However, the intrinsic interactions between 2D materials and ILs are rarely addressed. This work studies the intersystem Coulomb interactions in IL-functionalized InSe field-effect transistors by displacement current measurements. We uncover a strong self-gating effect that yields a 50-fold enhancement in interfacial capacitance, reaching 550 nF/cm2 in the maximum. Moreover, we reveal the IL-phase-dependent transport characteristics, including the channel current, carrier mobility, and density, substantiating the self-gating at the InSe/IL interface. The dominance of self ...
最新消息
演講資訊
08
2023
活動資訊
With the recent advances in artificial intelligence (AI) or machine learning (ML) techniques, we have seen a rise in the application of ML in various fields of science. But, on the other hand, many chemists are still wondering if using this powerful ML in a black box manner will help their research or not. In this workshop, we aim to shed some light on this.
In the morning, we will open with Prof. William Green of MIT giving a talk on “Quantitative Machine Learning for Chemical Sciences”. Then, we will have Prof. Yi-Pei Li (NTU) and Tzuhsiung Yang (NTHU) give us an idea of the basic background behind ML and what it can and can not do. In addition, we will have hands-on use of ML techniques for material property prediction, generating molecular structure for desired property, and organic chemistry predictive retrosynthesis. Lastly, we will have some lab members demo and share their experience using ML for their research.
We invite interested PIs to please join us to learn more about ML techniques and their possible application in chemical problems. Since we will have hands-on, please bring your laptop computers, and 1 lab member can also join you at the workshop.
2023-06-26 上午 09:00 ~ 2023-06-30 下午 05:30
It is our great pleasure to inform you that the 17th International Conference on Squeezed States and Uncertainty Relations (ICSSUR 2023) will take place on 26-30 June 2023 in Taipei, Taiwan.
The event will be in-person format with regular and poster sessions. As you may know ICSSUR has a long history back to 1991, covering a wide range of topics from quantum optics to quantum atom optics and quantum information.
This time, the venue of this 5-day event is National Taiwan University (NTU)campus near the Gongguan MRT station, in Taipei, and we also plan a half-day excursion to our National Palace Museum with the banquet there (Silks Palace).
2023-07-03 上午 09:00 ~ 下午 05:10
With the recent global climate issues, controlling CO2 concentration in the atmosphere is a major target for study in many fields. To build on the global partnership funding of Thailand under Program Management Unit for Human Resources & Institutional Development, Research, and Innovation under N39(S3P19) program 2023 “Development of manpower in international communities for Catalysis/Electrocatalysis for Zero CO2 Emission (CZCE): Searching a new pathway for the Net-Zero-CO2 Emissions in Chemical Industry”, we bring together researchers in Taiwan (Institute of Atomic and Molecular Sciences) and Thailand (Vidyasirimedhi Institute of Science and Technology, National Nanotechnology Center National Science and Technology Development Agency) for research exchange and discussion.
We will host The First Joint Thailand-Taiwan Workshop on Catalysis for Carbon Neutrality at Poe Lecture Hall, IAMS on July 3, 2023. In addition to cutting-edge talks by researchers in this challenging field, we will have student poster presentations. We invite those that are interested in participating in our event.
2023-10-06 上午 09:00 ~ 2023-10-09 下午 08:00
We are happy to announce that the 6th International Conference on Molecular Simulation (ICMS 2023) will be held from October 6th to 9th 2023 in the venues of the National Taiwan University, Taipei, Taiwan.
Molecular simulations have become an essential tool in Physics, Chemistry, Biological/Material Sciences, and Engineering over the last few decades. The International Conference on Molecular Simulations (ICMS) was initiated by the Molecular Simulation Society of Japan in 1994 to promote molecular simulations as a platform for inter-disciplinary research. The first three meetings were held in 1994, 2004, and 2013 in Fukui, Tsukuba, and Kobe, respectively. After the 4th and 5th ICMS in Shanghai 2016 and Jeju 2019 with hundreds of participants from more than 20 countries, the 6th ICMS was initially scheduled to take place in Taipei in 2022. However, the meeting has so far been hindered due to the global COVID-19 pandemic.
Now, with the world recovering from COVID-19 and Taiwan lifting its travel restrictions, we hope that the ICMS 2023 will not only provide a platform for scientists and engineers to meet in person again and to share state-of-the-art development in molecular simulations. We also hope it will facilitate international collaborations and promote scientific and technological advances through molecular simulations.
地址： 106319 台北市羅斯福路四段一號 或 106923 臺北臺大郵局 第23-166號信箱
電話：886-2-2362-0212 傳真：886-2-2362-0200 電子郵件：iamspublic@gate.sinica.edu.tw
最後更新於 2023-06-05 16:09:29
