The National Synchrotron Radiation Research Center is a 1.5 GeV third-generation synchrotron at the Hsinchu Science Park in East District, Hsinchu City, Taiwan as the agency under the Ministry of Science and Technology of the Republic of China.There are twenty-six operational beamlines and four under construction; the NSRRC also operate two beamlines at SPring-8 in Japan. They cover a wide range of functionality, from IR microscopy to X-ray lithography. Wikipedia.
Bahou M.,National Chiao Tung University |
Wu Y.-J.,National Synchrotron Radiation Research Center |
Lee Y.-P.,National Chiao Tung University
Angewandte Chemie - International Edition | Year: 2014
Large protonated polycyclic aromatic hydrocarbons (H+PAHs) are possible carriers of unidentified infrared (UIR) emission bands from interstellar objects, but the characterization of infrared (IR) spectra of large H+PAHs in the laboratory is challenging. IR absorption spectra of protonated coronene (1-C24H13 +) and mono-hydrogenated coronene (1-C24H13 .), which were produced upon electron bombardment of parahydrogen containing a small proportion of coronene (C24H12) during matrix deposition, were recorded. The spectra are of a much higher resolution than those obtained by IR multiphoton dissociation by Dopfer and co-workers. The IR spectra of protonated pyrene and coronene collectively appear to have the required chromophores for features of the UIR bands, and the spectral shifts on an increase in the number of benzenoid rings point in the correct direction towards the positions of the UIR bands. Larger protonated peri-condensed PAHs might thus be key species among the carriers of UIR bands. Protonated pyrene and coronene collectively appear to have the required chromophores for the unidentified infrared (UIR) emission bands from interstellar objects, and the spectral shifts on an increase in the number of aromatic rings point in the correct direction towards the positions of the UIR bands. Larger protonated peri-condensed polycyclic aromatic hydrocarbons might thus be important species among the carriers of UIR bands. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Chen W.-T.,National Taiwan University |
Sheu H.-S.,National Synchrotron Radiation Research Center |
Liu R.-S.,National Taiwan University |
Attfield J.P.,University of Edinburgh
Journal of the American Chemical Society | Year: 2012
Red or yellow phosphors excited by a blue light-emitting diode are an efficient source of white light for everyday applications. Many solid oxides and nitrides, particularly silicon nitride-based materials such as M 2Si 5N 8 and MSi 2O 2N 2 (M = Ca, Sr, Ba), CaAlSiN 3, and SiAlON, are useful phosphor hosts with good thermal stabilities. Both oxide/nitride and various cation substitutions are commonly used to shift the emission spectrum and optimize luminescent properties, but the underlying mechanisms are not always clear. Here we show that size-mismatch between host and dopant cations tunes photoluminescence shifts systematically in M 1.95Eu 0.05Si 5-xAl xN 8-xO x lattices, leading to a red shift when the M = Ba and Sr host cations are larger than the Eu 2+ dopant, but a blue shift when the M = Ca host is smaller. Size-mismatch tuning of thermal quenching is also observed. A local anion clustering mechanism in which Eu 2+ gains excess nitride coordination in the M = Ba and Sr structures, but excess oxide in the Ca analogues, is proposed for these mismatch effects. This mechanism is predicted to be general to oxynitride materials and will be useful in tuning optical and other properties that are sensitive to local coordination environments. © 2012 American Chemical Society.
News Article | September 8, 2016
When you squeeze something, you usually expect it to shrink, particularly when the pressure exerted acts uniformly from all sides. However, there are materials which, when subjected to hydrostatic pressure, elongate slightly in one or two directions. During the search for optimal compounds for hydrogen storage, researchers made an accidental, albeit very interesting, discovery: Under increasing pressure, one of the tested materials elongated significantly. "Usually, the increase in dimensions observed in materials with negative compressibility subjected to high hydrostatic pressure is small. We are talking here about values of the order of a single percentage point or even less. We have found a material of very high negative compressibility, of up to 10% in one direction. Interestingly, the elongation occurred abruptly at a pressure of approx. 30 thousand atmospheres," says Dr. Taras Palasyuk (IPC PAS). Dr. Palasyuk is conducting research on materials subjected to hydrostatic pressures of one to several million atmospheres (the prefix hydro- means that the pressure acts on the material from all sides). Such high pressures are produced in the laboratory using diamond anvils, between which a micrometre-sized sample is placed. The sample is in a seal ensuring that the exerted pressure acts on the test material uniformly from all directions. To lead to an increase in pressure, the anvils are compressed by means of a screw. A ruby crystal placed next to the sample acts as a pressure gauge. It changes its mode of fluorescence depending on the pressure exerted upon it. The volume of the material samples exposed to increasing pressure decreases, which is usually associated with a reduction of all spatial dimensions. However, there are also atypical crystalline materials whose volume decreases during compression (because thermodynamics dictates that it must) while at the same time, the crystal elongates in one or two directions. The mechanism responsible for this elongation has always been of a geometric nature: Under pressure, individual elements of the crystal structure simply moved relative to each other to varying degrees in different directions. "In our laboratory, using laser light, we analyzed how the manners of vibration of molecules in the crystal changed with increasing pressure, and on this basis, we drew conclusions about the structure of the material. We quickly discovered that in the crystal we were examining, which was sodium amidoborane, the elongation could not be explained by changes in geometry alone," says Ph.D. student Ewelina Magos-Palasyuk, the lead author of the publication in the journal Scientific Reports. Sodium amidoborane is a relatively readily available compound with the chemical formula Na(NH BH ) forming transparent crystals with an orthorhombic structure. The results of research on crystals of this compound obtained at the IPC PAS using Raman spectroscopy were confronted with theoretical model predictions. It turned out that the negative compressibility of sodium amidoborane crystals has to be a consequence of the elongation of the chemical bonds between nitrogen, hydrogen, boron and nitrogen, caused by the abrupt formation of new hydrogen bonds between adjacent molecules in the crystal. "Sodium amidoborane is thus the first material known to us where the negative compressibility is primarily of a chemical nature," says Dr. Taras Palasyuk, stressing that in contrast to other materials in which the symmetry of the crystal structure changes under high pressure, there are no drastic changes in sodium amidoborane. He adds: "Our preliminary results, obtained by X-ray diffraction at the National Synchrotron Radiation Research Center in Taiwan, also confirm that the material retains its original symmetry. It is precisely because it does not have to rebuild that the increase in the linear dimensions occurs here in such an abrupt manner." The discovery of a previously unknown mechanism responsible for negative compressibility opens up interesting avenues in the search for new materials with similarly exotic physical properties. The significant, abrupt and reversible increase in length of the sodium amidoborane crystals at a clearly defined value of pressure makes the material an interesting candidate for such applications as components of pressure detectors of a threshold pressure of around 30 thousand atmospheres (in industry, pressures as high as 300 thousand atmospheres are used). Another potential application of sodium amidoborane could be active bulletproof vests, which would behave like airbags in a car under the influence of the sharp increase in pressure caused by the projectile strike. Explore further: Superman can start worrying—we've almost got the formula for kryptonite More information: Ewelina Magos-Palasyuk et al, Chemically driven negative linear compressibility in sodium amidoborane, Na(NH BH ), Scientific Reports (2016). DOI: 10.1038/srep28745
Lee S.-H.,National Synchrotron Radiation Research Center
Physical Chemistry Chemical Physics | Year: 2010
We investigated the photodissociation dynamics of tetrahydrofuran (c-C 4H8O) at 193.3 nm in a molecular-beam apparatus using photofragment-translational spectroscopy and direct vacuum-ultraviolet (VUV) photoionization. Five dissociation channels leading to products with m/z ratios appropriate for CH2CH2CH2 + H2CO, CH2CHCH2 + CH2OH, H + CH2CH 2 + CH2CHO, CH2CH2 + CH3 + HCO and CH2CH2 + CH2CO + H2 were identified; their branching ratios were determined to be 0.40, 0.25, 0.04 0.29 and 0.02, respectively. Secondary dissociations from nascent products CH 2CH2CH2CHO to CH2CH2 + CH2CHO and from CH2CH2O to CH3 + HCO and likely to CH2CO + H2 were observed. We measured distributions of product kinetic energy, average kinetic-energy release, and fractions in translation for each dissociation channel. The formation of CH 2CHCH2 + CH2OH indicates that hydrogen migration occurs before complete fragmentation. All photofragments have nearly isotropic angular distributions, with β values less than 0.05. The photodissociation of tetrahydrofuran into five channels is proposed to proceed mainly on the ground state potential-energy surface following ring opening and efficient internal conversions. © the Owner Societies.
National Synchrotron Radiation Research Center | Date: 2013-11-18
An apparatus for generating a pulsed magnetic field includes an insulating body, an electrical conductor positioned on the insulating body, and a ferromagnetic body having a hollow portion, wherein the insulating body and the electrical conductor are positioned in the hollow portion. In some embodiments of the present disclosure, the electrical conductor has at least one gap separating the electrical conductor into at least two parts, thereby allowing a current to flow through the at least two parts in parallel to generate a magnetic field in the insulating body.
National Synchrotron Radiation Research Center | Date: 2015-03-25
An X-ray mask structure (10) includes a unibody support substrate (11) having at least one thinned portion (21) surrounded by a wall portion (25), a top layer (15B) disposed on the at least one thinned portion of the support substrate, and a plurality of X-ray absorber patterns (35) disposed on the top layer over the at least one thinned portion. The top layer and the at least one thinned portion form a laminated membrane, wherein the at least one thinned portion and the wall portion provide mechanical support for the top layer, and the laminated membrane provides mechanical support for the plurality of X-ray absorber patterns.
National Synchrotron Radiation Research Center | Date: 2013-11-15
An X-ray mask structure includes a unibody support substrate having at least one thinned portion surrounded by a wall portion, a top layer disposed on the at least one thinned portion of the support substrate, and a plurality of X-ray absorber patterns disposed on the top layer over the at least one thinned portion. The top layer and the at least one thinned portion form a laminated membrane, wherein the at least one thinned portion and the wall portion provide mechanical support for the top layer, and the laminated membrane provides mechanical support for the plurality of X-ray absorber patterns.
National Synchrotron Radiation Research Center | Date: 2011-03-17
The present invention discloses a package structure of an inkjet-printhead chip. The structure includes: a nozzle structure of a print element including an ink chamber layer, a nozzle base layer on the ink chamber layer, and a nozzle layer on the nozzle base layer, wherein a plurality of nozzle through holes are set in the nozzle layer and pass through an ink chamber of the ink chamber layer; a flexible substrate set on the nozzle layer, wherein there is at least an opening set in the flexible substrate to expose those nozzle through holes; and a chip set under the ink chamber layer. Besides, the present package method is to utilize the micro-manufacturing process to form the nozzle structure of a print element and the tape automatic bonding process to bond the flexible substrate on the nozzle layer and the chip under the ink chamber layer.
National Synchrotron Radiation Research Center | Date: 2014-04-29
A relief valve assembly includes a relief valve, a hollow shell disposed on the relief valve so as to form a relieving chamber, and a cap mounted to the hollow shell and closing off a distal end of the relief valve to an external environment. The hollow shell has a distal aperture and a proximal aperture, and the distal end of the relief valve is inserted into the hollow shell through the proximal aperture and protrudes through the distal aperture. The relief valve includes a relief port forming a fluid flow path between a valve chamber of the relief valve and the relieving chamber, and the hollow shell extends past the relief port along a longitudinal axis of the relief valve. The relief valve includes a slide member configured to move in response to an over-pressure condition, and a fluid vents from the valve chamber to the relieving chamber through the relief port.
National Synchrotron Radiation Research Center | Date: 2015-04-10
An electrochemical capacitor includes a positive electrode, a negative electrode disposed proximally to the positive electrode, and a non-aqueous electrolyte, wherein the positive electrode and the negative electrode are immersed in the non-aqueous electrolyte, and a case is presented in the energy storage system to accommodate the non-aqueous electrolyte, the positive electrode, and the negative electrode. The positive electrode has a porous matrix having a plurality of micrometer sized pores and nanostructured metal oxides, wherein the porous matrix is a 3-dimensional (3D) mesoporous metal or a 3D open-structured carbonaceous material, and the nanostructured metal oxides are coated inside the plurality of pores of the porous matrix. The non-aqueous electrolyte includes organic compounds having at least one acylamino group and lithium salts characterized as LiX, wherein Li is lithium and X comprises SCN^(); the organic compounds are cyclic compounds; and the cyclic compounds comprise 2-oxazolidinone, ethyleneurea, or the combination thereof.