September
20,2016
Ming-Wen Chu ,
CCMS
Host:
Yuan-Huei
Chang
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Emergent Charge
Condensations
at Two-Dimensional Oxide Interfaces
Abstract
With the assistance
of modern thin-film growth techniques, perovskite oxides with a
three-dimensional crystal structure can now be grown in a
layer-by-layer manner at atomic-level precision on heterostructural
substrates, opening up vast opportunities for unprecedented phenomena
at the two-dimensional (2D) oxide interfaces. The emergence of a
conductive interface between the two band insulators, LaAlO3 (LAO) and
SrTiO3 (STO), represents the most celebrated exemplification in this
context. Up to the date, a plethora of unexpected properties have been
established at oxide heterointerfaces, ranging from 2D electron gas, 2D
superconductivity, 2D orbital reconstruction to 2D magnetic ordering.
However, why can the oxide interfaces be so surprising? This remains an
outstanding problem to be addressed promptly. In this Colloquium, I
will elucidate on how we disentangled the puzzle using simultaneous
STEM-EELS tackling of charge, lattice, and electronic-structure degrees
of freedom, atom-by-atom and unit-cell-by-unit-cell. The localization
of a 2D electron density at an insulating (Nd,Sr)MnO3/STO interface
[PRB, 2013], the condensation of the 2D interfacial charges in
(Nd,Sr)MnO3/STO into one-dimensional electron chains [Nature Commun.,
2014], and hidden lattice instabilities as the origin of the conductive
LAO/STO interface [Nature Commun., 2016] were readily resolved.
Perspectives on 2D oxide-interfacial phenomena and STEM-EELS
instrumentations will also be discussed.
Brief Bio
Dr. Ming-Wen Chu obtained his PhD degree in Materials Science in 2002
at University of Nantes, France. He then moved to Max-Planck Institute
of Microstructure Physics, Halle (Germany), for his first postdoctoral
research in 2003 and National Institute for Materials Science, Tsukuba
(Japan), for the second postdoctoral work in 2004. In January 2005, he
joined Center for Condensed Matter Sciences (CCMS) at National Taiwan
University as assistant research fellow. He was promoted to associate
research fellow in 2009 and to research fellow in 2014. Dr. Chu’s
graduate and post-graduate trainings have been on x-ray crystallography
and electron scattering of oxides. After having joined CCMS, he changed
his research focus to atomically-resolved electron spectroscopy using
scanning transmission electron microscopy (STEM) in conjunction with
electron energy-loss spectroscopy (EELS) and readily demonstrated the
first unveiling of plasmonic dark modes in 2009 (highly cited paper in
Physics, 2015), the first fluorescent-X-rays elemental map at atomic
resolution in 2010, and the first unit-cell-by-unit-cell charge
counting at oxide interface in 2013. He is now one of the most active
experts in STEM and EELS and his recent research interests are centered
on atomic-scale unraveling of emergent phenomena at oxide interfaces.
October 04,2016
Guang-Yu Guo,
NTU-Physics
Host:
Yuan-Huei
Chang
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Quantum Hall Effect
without Applied Magnetic Field
Abstract
The integer
quantum Hall effect (IQHE), first found in 1980, is one of the most
important discoveries in condensed matter physics. When a strong
perpendicular magnetic field is applied to a 2D electron gas at low
temperatures, the Hall conductance is precisely quantized in the
fundamental conductance quantum (e2/h) due to Landau-level
quantization. This quantization was soon found to be connected with the
topologically nontrivial 2D insulating band structure, characterized by
a topological invariant (the Chern number), and the associated
dissipationless conducting edge states. This implies that the IQHE can
also occur in an insulating magnetic material with a nonzero Chern
number (Chern insulator) without applied magnetic field. Due to its
fascinating topological properties and potential applications in
designing low power electronics and spintronics, intensive theoretical
and experimental studies have recently been made in search for this
spontaneous IQHE (better known as quantum anomalous Hall (QAH) effect)
in real materials, leading to the recent observation of the QAH effect
in magnetic impurity-doped topological insulators at 30 mK. In this
talk, I will demonstrate, using first-principles calculations, that
high temperature spontaneous IQHE would occur in ferromagnetic
superlattices of heavy transition metal perovskites and also in layered
chiral antiferromagnetic oxides. Furthermore, I will explain that the
QAH phases in these oxides originate from two distinctly different
mechanisms, namely, the conventional one due to the presence of both
the relativistic spin-orbit coupling and ferromagnetism in the
perovskite superlattices and the exotic quantum topological Hall effect
caused by topologically nontrivial magnetic structure in the chiral
antiferromagnets.
Brief Bio
Guang-Yu Guo is currently a Distinguished Professor of NTU Physics Dept
and also a National Chair Professor of the Ministry of Education. He
received his PhD from Cambridge University in 1987. He joined the NTU
Physics Faculty in 1998 after working in Daresbury Laboratory, UK for
11 years as a postdoc, higher and senior staff scientist. He also
worked in National Chengchi University as a chair professor and the
founding director of the Graduate Institute of Applied Physics during
2009-2013. He has been fruitfully conducting research in condensed
matter and materials physics in the past 29 years, publishing over 200
journal papers with over 5000 citations and h-index of around 40. He
has won several academic awards and honors including the National
Science Council Outstanding Research Awards (1998, 2004, 2009) and the
Ministry of Education 57th Academic Award (2013) and 19th National
Chair Professorship (2015). He is an elected Fellow of PSROC (2005),
APS (2005) and Institute of Physics (UK) (2013).
Slides
October 11,2016
Pablo Laguna,
Georgia
Tech
Host:
Mei-Yin
Chou
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
When Black Holes Collide:
The Birth of Gravitational Wave Astronomy
Abstract
The Laser Interferometer Gravitational-wave Observatory (LIGO) has
recently detected for the first time gravitational waves. The
observations have confirmed a key prediction of Einstein’s Theory of
General Relativity, that space-time is a dynamical entity. The
detections are also the first direct observation of the collisions of
black holes and of a spinning black hole. I will give a tour of this
breathtaking discovery that marks the birth of gravitational wave
astronomy.
Brief Bio
Dr. Pablo Laguna is a school chair and professor of Georgia Tech.
Physics Department. He has been the director of center for relativistic
astrophysics since 2008. He received his PhD from University of Texas
at Austin. Before he started as an assistant professor at Dept. of
Astronomy and Astrophysics in Penn State University, he did three
postdoc training in University of Texas at Austin, Drexel University
and Los Alamos National Laboratory. He was promoted to be an associated
professor at Penn State in 1998 and then became a professor at Penn
State in 2000. His research interest is numerical relativity &
computational astrophysics simulations of compact object binaries.
October 18,2016
Bruce
McKellar,
IUPAP
Host:
Xiao-Gang
He
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
The He-McKellar-Wilkens
phase
in atomic
beams
and Bose-Einstein condensates
Abstract
The He-McKellar-Wilkens phase acquired when an electric dipole
completes a circuit in a radial magnetic field, and its dual, the
Aharonov-Casher Phase acquired when a magnetic dipole completes a
circuit in a radial electric field, are topological phases only for
specific field configurations, and even then only for configurations
which cannot be exactly realised experimentally. Therefore the early
work on these phases concentrated on defining the conditions under
which the phases are topological and building. A major step towards the
experimental realisation of the HMW phase was the observation that the
electric field needed to induce the electric dipole completely changed
the conditions under which the phase was topological. This led to the
experimental observation of the topological HMW phase in an atomic
beam, and subsequently the first atomic beam observation of the
topological AC phase. I review the physics of these phases and their
experimental realisation
More recently the possibility of using these phases to drive persistent
current in Bose-Einstein Condensates has been pointed out. It turns out
that the HWM phase can be used in this way with achievable electric and
magnetic fields, but the AC phase requires unachievable fields. As I
demonstrate, in this case the late-comer comes out first!
Brief Bio
Bruce McKellar received his PhD from the University of Sydney in 1965,
and was immediately appointed to the Faculty. After two years as a
Member of the Institute for Advanced Study in Princeton, and a brief
time in Sydney, he was appointed as Professor of Theoretical Physics at
the University of Melbourne in 1972. He retired from that position in
2007 and is now an Honorary Professorial Fellow at the Centre of
Excellence for Particle Physics at the Terrascale (CoEPP) in the School
of Physics at the University of Melbourne. In November 2014 he became
President of the International Union of Pure and Applied Physics
(IUPAP), the first-ever Australian to take on this role.
His PhD was in theoretical nuclear physics. He moved to using methods
of particle physics, especially current algebra, to calculate the
effects of weak interactions between nucleons, and many body nucleon
forces. His work on weak interactions led to calculation of the
electric dipole moments expected for the nucleon and atoms in various
models of these interactions. This work then evolved into studies of
related CP violating effects in the B meson system.
McKellar and his students also did foundational work on the behaviour
of neutrinos propagating through a dense background of neutrinos as one
finds in the early universe. He Xiao-Gang of NTU and Bruce McKellar in
1993 proposed the topological phase now known as “He McKellar Wilkens”
phase, independently predicted by Wilkens 1994. This phase is the
subject of today’s colloquium.
In 2014, Bruce McKellar was appointed a Companion of the Order of
Australia (AC),for his service to science, particularly theoretical
physics, as an academic, educator and researcher, through seminal
contributions to scientific development organisations, and as an author
and mentor. The AC is Australia’s highest civilian honour.
October 25,2016
Jiunn-Yuan
Lin,
NCTU-Physics
Host:
Ming-Wen
Chu
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Heterostructures and
interfaces
of quantum materials
Abstract
Heterointerfaces of quantum materials hold promise for creating new
multifunctional properties that could not be realized in single-phase
bulk materials. The rich interplay between lattice, orbital, charge and
spin degrees of freedom at the interface has resulted in a number of
novel phenomena. We have achieved atomically precise interface control
of various kinds of interfaces. In this talk, I will focus on the
interfaces between cuprates and other quantum materials. The induced
ferromagnetism in superconductors, the charge density wave, and
few-layered CuO2 planes will be examples to discuss.
Brief Bio
Jiunn-Yuan Lin is Professor and Director of Institute of Physics at
National Chiao Tung University (NCTU). He received his Ph.D. in Physics
from Stony Brook University. After working at National Sun Yat-Sen
University in Taiwan as a research associate, he joined the faculty of
NCTU in 1997. His current research focus on the discovery, creation,
and understanding of novel quantum matter.
November 01,2016
In
Soo
Ko,
Postech
Host:
Wei-Shu
Hou
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
New Research Opportunities
with PAL-XFEL Facility
Abstract
PAL-XFEL project is aiming to produce 0.1 nm coherent X-ray laser to
photon beam users. In order to produce such photons, there are 10-GeV
electron linac based on S-band normal conducting accelerating
structures and a 150-m long out-vacuum undulator system. The project
was started in April 2011, and the 1.11 km-long building was completed
in February 2015. The installations of 10 GeV linac, undulator systems,
and beamlines have been completed by the end of 2015. The operation
permit was issued on April 12, 2016, and the beam commissioning was
started immediately. On April 25, the linac was able to accelerate
electron beams from RF photocathode electron gun to 10 GeV, which is
the design value. By the end of June 2016, the commissioning has
achieved its first goal by lasing 0.5 nm coherent X-ray photons. We
will pursue our effort to have a coherent X-ray of 0.1 nm by the end of
2016. Korean scientists as well as international ones will have new
research opportunities with PAL-XFEL facility from 2017, especially in
the fields of ultra-fast chemical studies and structural molecular
imaging.
Brief Bio
In Soo Ko graduated Seoul National University in 1975, and served as a
full time instructor at Korean Naval Academy in 1977-1980. He got his
Ph.D. in Physics (Plasma Physics) at University of California, Los
Angeles (UCLA) in 1987. He joined the Pohang University of Science and
Technology (POSTECH) as well as the Pohang Accelerator Laboratory (PAL)
in March 1988 when POSTECH launched the Pohang Light Source project. He
served the PAL Director from 2004 to 2007, and the Chair of Asian
Committee for Future Accelerators (ACFA) from 2009-2010. When the
PAL-XFEL project was launched in 2011, the Korean government appointed
him to lead the project until its completion in 2015. He is also a
professor in Physics at POSTECH.
November
15,2016
Hsiang-Kuang
Chang,
NTHU
Host:
Jiwoo
Nam
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
The Compton Spectrometer
and Imager (COSI) Project
Abstract
The Compton Spectrometer and Imager (COSI) project is an effort to
develop the next generation Compton telescope of higher sensitivity.
COSI is currently a balloon-borne telescope project. The heart of COSI
is an array of cross-strip germanium detectors, each with 15mm x 80mm x
80mm dimension and full 3D position resolution of less than 2 mm^3.
COSI performs Compton spectroscopic imaging in the 0.2-10 MeV gamma-ray
band with a field of view about 50 degrees across and capability of
polarization measurement. It is also well suitable for monitoring
transient events. A balloon flight carrying a 10-detector array was
launched from Fort Sumner, NM, in May 2009, which lasted for 38 hours.
Another flight carrying 12 detectors was launched from McMurdo,
Antarctica on December 29, 2014, and lasted for 44 hours. The most
recent flight was launched from Wanaka, New Zealand, in May with a
super-pressure balloon flying for 47 days. During this flight, COSI
discovered GRB160530A. The COSI collaboration is now working for the
next flight in spring 2018, to launch again from Wanaka, New Zealand,
for a 100-day flight. I will report the science and design, past
flights, current status and the future of the COSI project. COSI is a
join effort of several institutions in Taiwan, US and France.
Brief Bio
●Bachelor of Science in Physics, Department of Physics, National Tsing
Hua University (NTHU), Hsinchu, Taiwan, 1987
●Master of Science in Physics, Institute of Physics, National Taiwan
University (NTU), Taipei, Taiwan, 1991
●Doctor of Natural Science in Astronomy, Institute of Astrophysics and
Extraterrestrial Research, Bonn University, Bonn, Germany, 1994
●Postdoctoral Research Associate, Los Alamos National Lab, USA, 1994 -
1996
●NSC Postdoctoral Fellow, Department of Physics, National Tsing Hua
University, 1996 - 1997
●Assistant, Associate and Full Professor, Department of Physics and
Institute of Astronomy, National Tsing Hua University, 1997 - present
November
22,2016
Shih-I Chu,
NTU-Physics
Host:
Yuan-Huei
Chang
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Attosecond Science
and Ultrafast Technology
Abstract
Attosecond (10^-18 sec) science represents a new scientific frontier in
atomic, molecular, and optical physics and condensed matter physics in
the 21st century. Attosecond science is still in its infancy, yet
impressive results and discoveries are already emerging. Currently
attosecond laser technology has reached a point where isolated
ultrashort XUV pulses with pulse lengths of the order of 100 attosecond
or less are produced in several laboratories in the US as well as
worldwide. This ultrafast technology enables the real-time probing of
electron dynamics in atoms, molecules and surfaces at the natural time
scale of the electronic motion in matter. Scientists are now able to
manipulate and steer electrons using laser fields, allowing them to
probe molecular orbital tomography, recollision physics and ionization
dynamics, etc., on attosecond timescales. Explorations using such novel
technology of attosecond XUV pulses have revealed a number of ultrafast
dynamics in physical, chemical, and biological systems that have never
been seen before. Other promising future applications of attosecond
technology include biological imaging, ultrafast tool for probing
chemical reaction and nanoscience, medical application, solar cells to
artificial photosynthesis, high-power photonics, and information
technology, etc.
In this talk, after a brief presentation of recent highlights of
attosecond science, I’ll discuss some recent development of ab initio
theoretical formalisms and accurate time-dependent methods for
nonperturbative treatment of highly nonlinear multiphoton processes in
the presence of ultrashort laser pulses. Applications of these methods
for the study of the optimal control of very high-order (100th – 5000th
order) harmonic generation processes, the production of shorter and
shorter attosecond laser pulses, and the probing of real-time electron
dynamics, sub-cycle transient spectroscopy, and multiple rescattering
processes will be discussed.
Brief Bio
Shih-I Chu is currently a Distinguished Research Chair Professor of NTU
Physics Department and the Director of the Center for Quantum Science
and Engineering (CQSE). He received his Ph.D. degree in Chemical
Physics from Harvard University in 1974. He was a postdoc fellow at
Joint Institute for Laboratory Astrophysics (JILA) and a J. Willard
Gibbs Lecturer at the Physics Dept. of Yale University. He joined the
chemistry faculty position of the University of Kansas (KU) in 1978 and
has been the Watkins Distinguished Professor since 1990. He moved to
the NTU Physics Department in Jan. 2007. Dr. Chu received a number of
international academic awards and honors for his pioneering
contributions in atomic, molecular, and optical (AMO) physics, chemical
physics, and molecular astrophysics. He was elected as an Academician
of the Academia Sinica in 2006 and a Fellow of the World Academy of
Sciences in 2012. His research interests involve the development of a
number of new theoretical formalisms, and accurate computational
methods for in-depth ab initio exploration of a broad range of problems
of current interest in quantum science and technology. His works have
significant impact to the advancement of strong-field AMO physics,
attosecond ultrafast science, quantum chaos and fractal, many-body
resonance theories, molecular astrophysics, quantum and optimal
control, and quantum computing and information, etc.
November
29,2016
Tai-Chang
Chiang,
UIUC
Host:
Minn-Tsong
Lin
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Novel Electronic Effects
in Atomically Uniform Ultrathin Films
Abstract
Atomically uniform films can be made for various overlayer-substrate
combinations (such as Ag, Pb, Sb, … on Si, Ge, Fe, …), many of which
are not even lattice matched. These films show remarkable property
variations as the film thickness is built up in atomic-layer
increments. The thermal stability of the film, its work function,
electron-phonon coupling, superconducting transition temperature, etc.
exhibit damped and modulated oscillations as the film thickness
increases toward the bulk limit. The underlying physics can be
understood generally in terms of the energetics of a coarsened
electronic structure of thin films and more specifically in terms of a
"one-dimensional shell effect" -- the quantized electronic levels in
the film are progressively filled at increasing film thicknesses just
like the elemental atomic shells in going through the periodic table.
The phase and the amplitude of the oscillations can be tailored by
surface/interface engineering that leads to changes in the surface
potential and the interface Schottky barrier or band mismatch. These
quantum size and confinement effects are important and observable at
film thicknesses well in the realm of practical device dimensions and
at room temperature, suggesting opportunities for applications. When
the films are made of topologically nontrivial materials, the electron
spin and its transport become relevant parameters. This talk will
discuss issues related to uniform film growth, general trends in
connection with reduced dimensions, surprising findings, and technology
potential.
Brief Bio
After receiving a B.S. in physics from the National Taiwan University
in 1971, Professor Chiang received his Ph.D. in physics from the
University of California, Berkeley in 1978. He joined the Department of
Physics at the University of Illinois in 1980 after working as a
postdoctoral fellow at the IBM T.J. Watson Research Center in Yorktown
Heights, NY.
Professor Chiang has done seminal research on the electronic
properties, lattice structure, and dynamic behavior of surfaces,
interfaces, and ultrathin films. He employs molecular beam epitaxy
techniques to create thin films and composite systems made of metals,
semiconductors, topological insulators, superconductors, and
charge-density-wave compounds, where functionality and novel properties
may emerge from quantum confinement and coherent coupling among the
components of the composite.
While his work focuses on basic scientific principles, many of the
systems under investigation have strong potential for applications. He
is credited for being the first one to create atomically uniform films
of thicknesses ranging from a single layer to well over a hundred
layers. Such films function as miniature electron interferometers in
which electrons bounce back and forth between the two boundaries to
form standing waves, also known as quantum well states. These effects
allow precise measurements of the electronic wavelength and the
kinetics of electron motion. Professor Chiang is an outstanding
theorist who is able to develop theoretical models for his experimental
results.
Early in his career, Professor Chiang did pioneering work on the
application of angle-resolved and core-level photoemission to surface,
thin film, and superlattice research. He was one of the first to
demonstrate that atoms of single-crystal surfaces have core level
binding energies different from the bulk atoms; this work led to the
development of quantitative methods for surface structure analysis. He
developed systematic methods for three-dimensional band structure
mapping, clarified the photoemission processes in terms of bulk and
surface effects, and was the first to report surface change density
oscillations near defects using scanning tunneling microscopy. His
research on x-ray thermal diffuse scattering for phonon mapping is now
a topic in textbooks.
Prof. Chiang has conducted his research using synchrotron radiation
facilities including the Synchrotron Radiation Center in Stoughton,
Wisconsin, the Advanced Light Source in Berkeley, California, the
Advanced Photon Source at the Argonne National Laboratory, and several
international facilities. He also conducts research at the free
electron laser facility LCLS in Stanford, California.
December 06,2016
Jianglai
Liu,
SJTU-Physics
and Astronomy
Host:
Xiao-Gang
He
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Deep underground xenon
observatory
in China – the PandaX experiment
Abstract
The particle physics nature of the dark matter and neutrinos are top
unknowns in modern physics. The Particle and Astrophysical Xenon
(PandaX) project is a series of xenon-based ultralow background
experiments in the China Jinping Underground Laboratory (CJPL)
targeting these big questions. The first and second stage experiments
(PandaX-I and II) both utilize dual-phase xenon time-projection chamber
(TPC) to carry out direct search for the dark matter particles.
PandaX-II, a half-ton scale experiment, is currently under operation,
and has recently produced world-leading limits to dark matter-nucleon
scattering cross section. The upgrade to a multi-ton experiment is
being planned in parallel. PandaX-III, currently under preparation as
well, will employ a gaseous xenon TPC with 200 kg of 136Xe target to
search for the neutrinoless double beta decay.
In this talk, I shall present an overview of the full project, the
latest results from the first 99-day run of PandaX-II, and future
prospects.
Brief Bio
1998 B.S. Nanjing University
2006 Ph.D. University of Maryland at College Park
2006-2010 Postdoc/Senior Postdoc, Caltech
2010-Now Shanghai Jiao Tong University, Assistant Professor (10-15),
Professor (15-Now)
Dr. Jianglai Liu has worked on various experiments in the intersections
of nuclear, particle, and astrophysics. He studied the strange form
factors of the nucleon at the Thomas Jefferson National Accelerator
Facility via parity-violating electron scattering (1999-2006), and
performed measurements of the axial-vector coupling constant using
ultracold neutron decays at the Los Alamos National Laboratory
(2006-2010). Currently he is the PI of the neutrino physics group at
the SJTU, working on the Daya Bay and JUNO neutrino experiments,
studying the fundamental properties of the neutrinos. He is in charge
of the detector calibration for both projects. Since 2010 he started
his endeavor on the PandaX experiment, a xenon-based direct dark matter
search at the China Jin-Ping Underground Laboratory, and is presently
serving as the deputy spokesperson of the project. Dr. Liu received the
best Ph.D. dissertation prize from Jefferson Science Association in
2006. He was selected into the “1000 Junior Talent Program” in China in
2011 and Outstanding Junior Investigator awards from NSFC in 2015.
December
13,2016
Niklas Hedin,
Stockholm
University
Host:
Tsyr-Yan
Yu
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Adsorbents for CO2 capture
Abstract
Reductions of emissions of greenhouse gases to the atmosphere are
needed to limit the effects of climate change. In most scenarios,
Carbon Capture and Storage (CCS) is a needed measure. However, it has
not been introduce because of public concerns when it comes to the
storage of CO2, other policy aspects, and the associated high energy
penalty. Adsorption-driven technologies have potential to reduce the
cost for CCS. Here, chemisorption and physisorption of CO2 have their
own advantages, which will be discussed in relation to the involved
chemistry and physics and to some extent the economics of CO2 capture.
Brief Bio
Niklas Hedin received his PhD in Physical Chemistry from Royal
Institute of Technology (KTH) in 2000. After the postdoctoral training
with both Prof. Bradley F. Chmelka at UC Santa Barbara and with Dr.
Sebastian C. Reyes at ExxonMobil’s central research laboratory, he was
appointed as an Assistant Professor (forskarassistent) and then Senior
Lecturer in Materials Chemistry at Stockholm University. Niklas Hedin
is currently a professor of Materials Chemistry; Department of
Materials and Environmental Chemistry (MMK), Stockholm University. He
has been the director of the Berzelii center EXSELENT on porous
materials since 2012.
His research interest is to study the molecular details of interfaces
in micro-heterogeneous materials. The main focus is currently on
adsorbents for carbon dioxide separation, involving synthesis,
adsorption, and more mechanistic studies. His secondary focus is on
developing sustainably derived nanoporous carbons with applications in
supercapacitors.
December
20,2016
Ann-Shyn
Chiang,
NTHU
Host:
Chen-Yuan
Dong
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Decoding the Brains
Abstract
Our brains
receive information from sensory neurons about our external environment
and internal organs. To understand how the brain processes information
and initiates motor outputs, scientists are constructing complete
wiring diagrams called “connectomes” that map all neural connections in
the brain and body. Taking Drosophila melanogaster as an example, I
will discuss challenges in building whole-body connectomes and how that
knowledge may help us better understand normal function and treat
disease.
Brief Bio
Received
Ph.D. (1990) and trained as a postdoctoral fellow (1992) in Rutgers
University, Ann-Shyn Chiang joined Department of Life Science, National
Tsing Hua University as an associate professor (1992), promoted as
professor (1997), took sabbatical to study Drosophila memory at Cold
Spring Harbor Laboratory (2001) and became the adjunct International
Faculty of Kavli Institute for Brain and Mind (KIBM) at the University
of California, San Diego (2011). For his contribution to our
understanding of memory formation using a connectomics approach, Chiang
was elected as an Academician of Academia Sinica (2014).
Chiang reconstructed a brain-wide wiring diagram in Drosophila (the New
York Times reported this discovery as the first step toward mapping
human brain) and published the first Cell (2007) paper from Taiwanese
scientists. Guiding by this connectomics map, he and his colleagues
discovered that long-term memory formation requires new protein
synthesis only in few brain neurons and published the first full
article in Science (2012) from Taiwanese scientists. He received many
awards, including: Outstanding Research Award, National Science Council
(2004, 2009, 2012), Outstanding Scholar Award, Foundation for the
Advancement of Outstanding Scholarship (2007), Academic Award of
Ministry of Education (2007), Outstanding Contributions in Science and
Technology of Executive Yuan (2008), TWAS Prize in Biology (2012), and
National Chair Award of Ministry of Education (2015). Chiang is
currently the Dean of College of Life Science, the Director of Brain
Research Center, and the Distinguished Chair Professor of National
Tsing Hua University.
December
27,2016
Dang-Sheng
Su ,
CAS-Chemical
Physics
Host:
Ming-Wen
Chu
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Carbon-based materials as
novel catalysts
Abstract
Nanocarbon
materials, especially carbon nanotubes (CNTs), exhibit unique
controllability of both its surface acidity/basicity and π-electron
density through curvature, surface functionalization including addition
of heteroatoms. Defects existing on the surface of nanocarbons can act
as isolated sites to anchor functional groups or activate molecules.
The long-range ordering of nanocarbon materials determines the
mechanical stability and the macroscopic properties (e.g. thermal and
electronic conductivities, oxidation resistance) that are superior to
the classical carbon materials such as activated carbon or carbon
black. Consequently, nanocarbon has become a test object as a new
alternative material to some currently used catalyst. A possible
application of nanocarbon as heterogeneous catalysts is attractive
since no precious or transition metals are used and open new
possibility for a sustainable catalysis. We have explored CNTs for the
dehydrogenation of ethylbenzene and alkane activation (C1-C5), and
studied the mechanism by both in-situ experiments and DFT calculations
identifying quinone-like carbonyl groups as the active sites. Recently
the study of nanocarbon as catalysts has been extended to the
hydrochalogenation, hydrogenation, epoxidation and oxygen insertion
reactions. Nanocarbons are all active in these reactions. However, the
active sites are different for different reactions. Surface
modification with heteroatoms such N, B, P can change significantly the
conversion/selectivity. The state-of-the-art of nanocarbon catalysis
will be presented with an outlook for practical application.
Brief Bio
Dr. Dangsheng
Su obtained his Bachelor degree in 1983 from Jilin University, Master
degree in 1986 from Jilin University, and Doctorate degree in applied
physics in 1991 at Vienna University of Technology, Austria. He has
worked as a postdoc and research associate at Fritz-Harbor Institute of
the Max Planck Society (Germany), Hahn-Meitner-Institute GmbH
(Germany), Vienna University of Technology (Austria) and Humboldt
University (Germany) from 1991 to 1999. From July, 1999, Dr. Su worked
as the director of electronic microscopy lab and leader of the
department of inorganic chemistry at Fritz-Harbor Institute of the Max
Planck Society (Germany), and then, he was selected as “overseas high
level talents” (thousands plans) in 2008 and moved to Shenyang National
Laboratory for Materials Science (China). He was also appointed as
visiting Professor at University of Messina (Italia), University of
Milano (Italia), University JAGIELLOŃSKI (Poland) and South China
University of Technology (China) etc. In 2016, he joined Dalian
Institute of Chemical Physics at Chinese Academy of Sciences as a
leader of Energy Research Resources Division.
Dr. Su has been in charge of IDECAT, CANAPE, EnerChem and
several other important research projects during his career in Germany,
and his research interests cover physics, chemistry, material,
catalysis and environment etc. He has 2 international patents and
published over 300 articles in the field of nano-carbon materials
synthesis, their structural analysis and catalytic activity etc. in
world-renowned scientific journals, such as Science, Angew. Chem. etc.
Dr. Su has also served as a guest editor for Micron, Catal. Today, and
ChemSusChem, and has already organized and edited several special
issues on electron microscopy, carbon catalysis and energy chemistry
etc.
January
03,2016
Chung-Yuan Mou,
NTU-Chemistry
Host:
Yuan-Huei
Chang
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
Nano-Confined Water
Abstract
Water under nano-confinement is different from normal water. It is
relevant to life and geoscience because much of the hydration
phenomenon in nature occurs in narrowly confined water. Studying
confined water will help one to understand the physicochemical effect
of water and its interaction with solutes in crowded environment.
Mesoporous silica materials with uniform pore size will be the
confining media in our study. By using neutron and X-ray scattering
techniques, we studied the density and diffusion of water under
nanoconfinement.
By confining solutes, solubility of a hydrophobic molecule such as Xe
in water under nanoconfinement will impact several related problems,
(a) solubility of methane in water within nanopores of rock under
fracking condition, (b) understanding how hydrophobic effect would be
changed in confined water, (c) how protein hydration would change under
confinement.
We studied hydration behavior of Xe in water confined in mesoporous
silica using Xe-NMR chemical shifts. Temperature change of the signal
allows us to determine the enthalpy of hydration. It was found that in
pore confined water, the hydration of Xe is more energetically
favorable than in bulk water. The increased solubility of Xe in
nanopore is in the same trend with computer simulation results of
confined methane.
Next, we employed mesoporous silica of matching pore sizes to confine
lysozyme in order to mimic enzyme in a crowded environment. The
stability and activity of
lysozyme immobilized in mesoporous silica nanoparticle (MSN) of various
pore sizes were studied and correlated to spectroscopic data of the
immobilized enzyme. It was found that the activity of the lysozyme
immobilized in the 5.6 nm mesopores of MSNs was higher than those of
native enzymes. The enhanced activity was attributed to subtle change
in hydration of lysozyme due to increased stability of hydrophobic
solvation.
Brief Bio
男；民39年3月15日；台灣省基隆市
現職：國立臺灣大學化學系教授(民67-)。
學歷：國立臺灣大學化學系學士(民55-59)、美國華盛頓大學化學博士(民60-64)。
經歷：美國奧勒崗大學博士後研究(民64-66)、美國普渡大學博士後研究(民66-67)、臺灣大學化學系副教授(民67-71)、臺灣大學化學系教授
(民71-)、比利時布魯塞爾自由大學訪問學者(民72-73)
、台灣教育改革審議委員會委員(民82-84)、臺灣大學化學系主任(民93-96)、遠哲科學教育基金會董事(民87-100)、天下文化出版顧問(民
80-)
、國科會化學審議會學門召集人(民88-90)、奈米科技國家型計畫顧問(民91-96)、國家科學委員會副主任委員(民101-103)、國立台灣大學
講座教授(民103-)、中央研究院院士(民105)、亞洲太平洋催化聯盟主席(民105)。