NSRRC Hosts the FEL Winter School

With continuous support from professors and scientists from the Stanford Linear Accelerator Center (SLAC), Indiana University, National Tsing Hua University, and National Chiao Tung University, the National Synchrotron Radiation Research Center (NSRRC) held the Free Electron Laser (FEL) Winter School on January 18–22, 2016, in Hsinchu, Taiwan for the fourth consecutive year. The five-day program was sponsored by the Physics Research Promotion Center (PRPC) under the Ministry of Science and Technology (MOST) and organized by the NSRRC. Thirty-four applicants were accepted, including 19 undergraduate students, 12 graduate students in master's programs, and three doctoral students.     

From NEXAFS spectroscopy to new flat panel displays: A story of basic science with technological impact

The Twentieth NSRRC Users' Meeting was held successfully at the National Synchrotron Radiation Research Center (NSRRC) in Taiwan from September 10th to 12th, 2014. The three-day meeting was the first such event to be held at the newly furnished Activity Center on the NSRRC campus, celebrating 20 years since the first NSRRC Users' Meeting and highlighting the prospective scientific frontiers marked by the newly established Taiwan Photon Source (TPS) storage ring.     

Twenty-First NSRRC Users' Meeting and Workshops

The Twenty-First NSRRC Users' Meeting was held at the Activity Center of the National Synchrotron Radiation Research Center (NSRRC) in Taiwan from September 9 to 10, 2015. At the same time, celebration of the first light of the Taiwan Photon Source (TPS), achieved at the end of 2014, highlighted the prospective scientific frontiers marked by the TPS storage ring. Jointly organized by the UEC Chair Ying-Hao Chu (National Chiao Tung Univ.) and Cheng-Maw Cheng (NSRRC), the meeting consisted of two plenary sessions and three featured workshops. Nearly 30 distinguished scholars, both domestic and international, were invited to present their research achievements. This highly anticipated event attracted an enthusiastic crowd of more than 370 synchrotron experts, users, and potential users.     

AOFSRR 2014 in Taiwan

The Asia-Oceania Forum for Synchrotron Radiation Research (AOFSRR) was formally established by Australia, China, Japan, South Korea, Singapore, Taiwan, and Thailand in 2006. Its objective is to strengthen the collaboration, as well as the inter-communication, among the synchrotron radiation facilities and to promote synchrotron radiation sciences and accelerator-based research in the Asia-Oceania region. Regular meetings have been organized to uphold its objective. The first scientific meeting of AOFSRR took place at KEK, Japan, in 2006. Member countries have been taking turns to organize meetings: Taiwan (NSRRC, 2007), Australia (Australian Synchrotron, 2008), China (SSRF, 2009), South Korea (POSTEC, 2010), Thailand (SLRI, 2012), and Japan (SPring-8, 2013). In 2014, the National Synchrotron Radiation Research Center (NSRRC) hosted the Eighth Asia-Oceania Forum for Synchrotron Radiation Research (AOFSRR 2014) from September 15th to 18th in Hsinchu, Taiwan. The NSRRC is located in the Hsinchu Science Park, within an hour's drive from Taipei, the largest city in Taiwan. Hsinchu is a city not only composed of historical landmarks but also the heartland of high-tech semiconductor industries in Taiwan.     

NSRRC Holds Dedication Ceremony for the Taiwan Photon Source's New Experimental Facility

More than 300 participants, including nearly 50 invited guests, attended the dedication ceremony for the Taiwan Photon Source's (TPS) new experimental facility at the National Synchrotron Radiation Research Center (NSRRC) on September 19, 2016. The special ceremony marked an important milestone that will dramatically change the course of Taiwan's scientific advancement in the coming years. Since the successful commissioning of the synchrotron accelerator TPS on New Year's Eve in 2015, the NSRRC has constructed an additional seven beamlines during Phase I of the TPS Experimental Facility Construction Project in order to channel an electron beam of 3 billion electron volts (GeV) away from the circular TPS storage ring into the experimental target samples. The ceremony, inaugurated by President Ing-Wen Tsai, officially announced the availability of these beamlines to scientific users worldwide.     

Taiwan Photon Source Delivers its Design Target with a Stored Current of 520 mA

After several months of upgrade work in the second phase of commissioning, the 3 GeV Taiwan Photon Source (TPS) of the National Synchrotron Radiation Research Center (NSRRC) successfully stored 520 mA of electron current, exceeding its design goal of 500 mA, in its storage ring on December 12, 2015. It is less than a year since the first light was achieved in the TPS store ring by using two room-temperature, five-cell PETRA radio frequency (RF) cavities.     

First Synchrotron Light of Taiwan Photon Source

On the last day of 2014, the newly completed second accelerator of the National Synchrotron Radiation Research Center (NSRRC), Taiwan Photon Source (TPS), delivered its first synchrotron light in the early afternoon. The electron beam energy of the TPS circulating in the storage ring has reached the design value of 3 GeV, and the stored beam current has achieved over 5 mA, marking a significant milestone for Taiwan's new synchrotron light source. After nearly five years of construction and development efforts in full scale, the successful commissioning of TPS will forever change the course of scientific research in Taiwan.     

View from HAXPES 2015

As the complexity of scientific research methods and applications deepens, collaboration among accelerator laboratories on hard X-ray technology is focused on the realization of broader scientific applications. The International Conference on Hard X-ray Photoelectron Spectroscopy (HAXPES) held its first gathering at ESRF in France in 2003. In 2015, the NSRRC hosted the Sixth HAXPES in Taiwan on March 30–April 3.     

HERCULES Launches its First Asia-Pacific School in Taiwan

HERCULES (Higher European Research Course for Users of Large Experimental System) School, co-organized by Université Joseph Fourier and Grenoble INP, has provided training for students, postdocs, and scientists from European and non-European universities and laboratories in the fields of synchrotron radiation and neutron science for condensed matter studies (biology, chemistry, physics, materials science, geosciences, industrial applications) since 1991. Throughout the years spent cultivating next-generation scientists, HERCULES School has been recognized as an internationally known training course. Given the success of the course in Europe, the Hercules Specialized Course (HSC) decided to cooperate with an overseas synchrotron radiation facility every five years to help nourish more young scientists outside Europe. The first overseas Hercules School, known as the Latin-American Edition of Hercules in Brazil, was co-organized by HSC and the Brazilian Synchrotron Light Laboratory in 2010. After this first successful overseas course in Latin America, Wen-Guey Wu, the past director of the Science and Technology Division of the National Science Council of Taiwan in France, recommended the National Synchrotron Radiation Research Center (NSRRC) in Taiwan to the founder and the previous chairman of HSC, Jean-René Regnard, for co-organizing the second overseas Hercules School. An Asia-Pacific Edition of HERCULES in Taiwan was then in place for 2015.     

Meeting Report: Australia's First Users Workshop

The Australian Synchrotron Research Program (ASRP) and the Australian Synchrotron (AS) held their first joint Users Workshop over three days in December 2005. The ASRP has been providing access for Australian users to the APS, NSRRC and the Photon Factory since 1996; the AS is under construction in Melbourne and at press time was scheduled to open in early 2007. The joint user workshop is one of an increasing number of collaborative projects between the two programs as they move forward towards an eventual combined Australian user program.     

Wolfgang Kiefer教授在第十九届全国光散射学术会议闭幕式上的致辞（英文）

正(2017年12月4日)Ladies and gentlemen,dear Professor Chen:Bringing this 19~(th) National Chinese Conference on Light Scattering to an end,it gives me great pleasure and honor to say a few words to you.     

Functions for patch test in finite element analysis of the Mindlin plate and the thin cylindrical shell

Current patch test for Mindlin plate element only satisfies the zero shear deformation condition. The patch test of non-zero constant shear for Mindlin plate problem cannot be performed. For shell element, the patch test does not even exist. Based on the theory of enhanced patch test proposed by Chen W J (2006), the authors proposed the enhanced patch test function for Mindlin plate and thin cylindrical shell elements. This enhanced patch test function can be used to assess the convergence of the Mindlin plate and cylindrical thin shell elements. Supported by the National Natural Science Foundation of China (Grant Nos. 50479058 and 10672032)     

Patch test function for axisymmetric element of conventional and couple stress theory

The enhanced patch test proposed by Chen W J (2006) can be used to assess the convergence of the problem with non-homogeneous differential equations. Based on this theory, we establish the patch test function for axisymmetric elements of conventional and couple stress theories, and reach an important conclusion that the patch test function for axisymmetric elements cannot contain non-zero constant shear. Supported by the National Natural Science Foundation of China (Grant No. 10672032)     

Design and construction of a compact end-station at NSRRC for circular-dichroism spectra in the vacuum-ultraviolet region

A synchrotron‐radiation‐based circular‐dichroism end‐station has been implemented at beamline BL04B at the National Synchrotron Radiation Research Center (NSRRC) in Taiwan for biological research. The design and performance of this compact end‐station for measuring circular‐dichroism spectra in the vacuum‐ultraviolet region are described. The linearly polarized light from the beamline is converted to modulated circularly polarized light with a LiF photoelastic modulator to provide a usable wavelength region of 130–330 nm. The light spot at the sample position is 5 mm × 5 mm at a slit width of 300 µm and provides a flux greater than 1 × 10¹¹ photons s^?1 (0.1% bandwidth)^?1. A vacuum‐compatible cell made of two CaF₂ windows has a variable path length from 1.3 µm to 1 mm and a temperature range of 253–363 K. Measured CD spectra of (1S)‐(+)‐10‐camphorsulfonic acid and proteins demonstrated the ability of this system to extend the wavelength down to 172 nm in aqueous solution and 153 nm in hexafluoro‐2‐propanol.     

Improvement on “Quantum Key Agreement Protocol with Maximally Entangled States”

Recently, Hsueh and Chen [in Proceedings of the 14th Information Security Conference, National Taiwan University of Science and Technology, Taipei, pp. 236–242, 2004] proposed a quantum key agreement (QKA) protocol with maximally entangled states. Their protocol allows two users to negotiate a secret key in such a way that no one can predetermine the shared key alone. This study points out two security flaws in their protocol: (1) a legitimate but malicious user can fully control the shared key alone; (2) an eavesdropper can obtain the shared key without being detected. A possible solution is presented to avoid these attacks and also Tsai et al.’s CNOT attack [in Proceedings of the 20th Cryptology and Information Security Conference, National Chiao Tung University, Hsinchu, pp. 210–213, 2010] on Hsueh and Chen protocol to obtain the shared key without being detected.     

A dedicated small‐angle X‐ray scattering beamline with a superconducting wiggler source at the NSRRC

At the National Synchrotron Radiation Research Center (NSRRC), which operates a 1.5 GeV storage ring, a dedicated small‐angle X‐ray scattering (SAXS) beamline has been installed with an in‐achromat superconducting wiggler insertion device of peak magnetic field 3.1 T. The vertical beam divergence from the X‐ray source is reduced significantly by a collimating mirror. Subsequently the beam is selectively monochromated by a double Si(111) crystal monochromator with high energy resolution (ΔE/E? 2 × 10^?4) in the energy range 5–23 keV, or by a double Mo/B₄C multilayer monochromator for 10–30 times higher flux (～10¹¹ photons s^?1) in the 6–15 keV range. These two monochromators are incorporated into one rotating cradle for fast exchange. The monochromated beam is focused by a toroidal mirror with 1:1 focusing for a small beam divergence and a beam size of ～0.9 mm × 0.3 mm (horizontal × vertical) at the focus point located 26.5 m from the radiation source. A plane mirror installed after the toroidal mirror is selectively used to deflect the beam downwards for grazing‐incidence SAXS (GISAXS) from liquid surfaces. Two online beam‐position monitors separated by 8 m provide an efficient feedback control for an overall beam‐position stability in the 10 µm range. The beam features measured, including the flux density, energy resolution, size and divergence, are consistent with those calculated using the ray‐tracing program SHADOW. With the deflectable beam of relatively high energy resolution and high flux, the new beamline meets the requirements for a wide range of SAXS applications, including anomalous SAXS for multiphase nanoparticles (e.g. semiconductor core‐shell quantum dots) and GISAXS from liquid surfaces.     

Chaos synchronization between two different 4D hyperchaotic Chen systems

This paper presents chaos synchronization between two different four-dimensional (4D) hyperchaotic Chen systems by nonlinear feedback control laws. A modified 4D hyperchaotic Chen system is obtained by changing the nonlinear function of the 4D hyperchaotic Chen system, furthermore, an electronic circuit to realize two different 4D hyperchaotic Chen systems is designed. With nonlinear feedback control method, chaos synchronization between two different 4D hyperchaotic Chen systems is achieved. Based on the stability theory, the functions of the nonlinear feedback control for synchronization of two different 4D hyperchaotic Chen systems is derived, the range of feedback gains is determined. Numerical simulations are shown to verify the theoretical results.     

基于非线性控制的超混沌Chen系统混沌同步

研究了基于非线性控制的超混沌Chen系统的混沌同步问题.基于Lyapunov稳定性理论，设计了非线性控制器，改进了Jiang和Huang等设计的同步误差系统的Lyapunov函数形式，理论证明了超混沌Chen系统的自同步和超混沌Chen系统与超混沌R?ssler系统的异结构同步.数值模拟进一步验证了所提出方案的有效性. 关键词： 超混沌Chen系统 自同步 异结构同步 非线性控制器     

A new four-dimensional hyperchaotic Chen system and its generalized synchronization

Based on the Chen chaotic system, a new four-dimensional hyperchaotic Chen system is constructed, and the basic dynamic behaviours of the system were studied, and the generalized synchronization has been observed in the coupled four-dimensional hyperchaotic Chen system with unknown parameters. The Routh--Hurwitz theorem is used to derive the conditions of stability of this system. Furthermore based on Lyapunov stability theory, the control laws and adaptive laws of parameters are obtained to make generalized synchronization of the coupled new four-dimensional hyperchaotic Chen systems. Numerical simulation results are presented to illustrate the effectiveness of this method.     

Complete explicit classification of parallel Lorentz surfaces in arbitrary pseudo-Euclidean spaces

A Lorentz surface of an indefinite space form is called parallel if its second fundamental form is parallel. Such surfaces are locally invariant under the reflection with respect to the normal space at each point. Parallel surfaces are important in geometry as well as in physics since extrinsic invariants of such surfaces do not change from point to point. Recently, parallel spacelike surfaces in an arbitrary indefinite space form are classified in Chen (2010) [20]. Moreover, parallel Lorentz surfaces in 4D indefinite space forms are completely classified in a series of recent articles Chen (submitted for publication) [16], Chen (submitted for publication) [17], Chen (in press) [18], Chen (2010) [19], Chen and Van der Veken (2009) [15] (see also Graves (1979) [12], Graves (1979) [13] and Magid (1984) [14] for some partial results). In this paper, we achieve the complete classification of parallel Lorentz surfaces in a pseudo-Euclidean space with arbitrary codimension and arbitrary index.