[en] The mobile large container inspection system (MLCIS) is a more flexible X-ray radiographic system than conventional fixed systems. Ideally, the X-ray detectors should be arranged along an arc with the source at the center. However, detectors of the MLCIS are arranged in an L-shaped frame and result in a factual image which is distorted compared with the ideal image. We propose a geometrical rectification algorithm to convert the factual image to the ideal image. We choose the dimension ratios of identical objects shown on the factual and processed images with our algorithm as a measure, and the results is desirable

[en] Negative thermal expansion material of ZrW₂O₈ has been successfully synthesized by rapid solidification with a CO₂ laser. The materials solidified in densely packed blocks with both smooth surface and dark green color. Raman spectroscopic and XRD analysis reveal that the samples solidified in an orthorhombic structure. It is analyzed that the compressive stress can be effectively reduced by lowering the laser scan speed. ZrW₂O₈ samples with cubic structure were produced when the laser scan speed was less than 2mm/s. The samples cooled by water are mainly dominated by α phase which demonstrates that a phase transition from γ to α has occurred after annealing. (paper)

[en] We have developed an irradiation technique that allows us to tune the magnetic properties of thin films without affecting their roughness. We discuss the mechanisms involved and the applications. He⁺ ion irradiation of Co/Pt multilayers lowers their magnetic anisotropy in a controlled way, reducing the coercive force and then leading to in-plane magnetization. By X-ray reflectometry, we study how irradiation-induced structural modifications correlate with magnetic properties. We also report the L1₀ chemical ordering of FePt by irradiation at 280 deg. C, and the consequent increase of magnetic anisotropy. Planar magnetic patterning at the sub 50 nm scale can be achieved when the irradiation is performed through a mask. New magnetic behaviors result from the fabrication process. They appear to arise from collateral damage. We model these effects in the case of SiO₂ and W masks. The planarity of irradiation-induced patterning and its ability to independently control nanostructure size and coercivity make it very appealing for magnetic recording on nanostructured media. Finally, possible applications to the granular media used in current hard disk drive storage technology are discussed

[en] NSRRC has been operating a 1.5 GeV synchrotron light source, the Taiwan Light Source (TLS), for over 15 years and has established a large user community. For the future development of synchrotron radiation research in Taiwan, a feasibility study report to construct a 3.0 GeV low-emittance storage ring, the Taiwan Photon Source (TPS), was issued in July 2005. The government approval of the TPS project was obtained in December 2007 and the machine will be built at current site of NSRRC. The project has progressed steadily since and reached several major milestones now: the architect firm has finished the site plan and civil design, the accelerator design has been fixed, and purchase of long-lead items begins its course. The TPS storage ring has a circumference of 518.4 meters with a concentric booster of 496.8 meters. The storage ring adopted a 24-cell double-bend structure with a 1.6 nm-rad natural emittance. There are six 12-m and eighteen 7-m ID straights. For user research, five new beamlines have been selected for the Phase I operations: the micro protein crystallography, the materials sub-micron diffraction, the inelastic soft x-ray scattering, the coherent x-ray scattering, and the nano probe beamlines. The civil construction is getting ready to start. The commissioning of the TPS storage ring is targeted for 2013.

[en] Fe-6.5wt%Si high silicon steel has superior magnetic properties. However, such high Si content results in room-temperature embrittlement and poor workability due to the formation of ordered intermetallic phases. Zone Melting Liquid Metal Cooling directional solidification technique was employed to produce the Fe-6.5wt%Si alloy with columnar-grained structures. The cooling rate of directional solidification plays a critical role in maintaining the grain growth, and the rate around 3 K/s is an optimum condition to form columnar-grained structure and to improve its ductility.

[en] Efficient three-step sequential three-photon near-infrared (NIR) quantum cutting in Tm³⁺-doped transparent oxyfluoride glass ceramics has been demonstrated, where an absorbed blue photon could be cut into three NIR photons at 1190, 1460, and 1800 nm with quantum yield greater than unity. On the basis of static and dynamic photoemission, monitored excitation, and time-resolved fluorescence spectra, we investigate in detail the underlying optoelectronic mechanism. Further development of an efficient triply-cutting material might open up a path towards ultra-efficient photonic devices, which enables more photons emitted than absorbed in the excitation process.

[en] Managing heat transport at nanoscale is an important and challenging task for nanodevice applications and nanostructure engineering. Herein, through in-situ engineering nanowire (NW)-electrode contacts with electron beam induced carbon deposition in a transmission electron microscope, Joule heat dissipation along individual suspended Indium Arsenide NWs is well managed to obtain pre-designed temperature profiles along NWs. The temperature profiles are experimentally determined by the breakdown site of NWs under Joule heating and breakdown temperature measurement. A model with NW-electrode contacts being well considered is proposed to describe heat transport along a NW. By fitting temperature profiles with the model, thermal conductance at NW-electrode contacts is obtained. It is found that, the temperature profile along a specific NW is mainly governed by the relative thermal conductance at the two NW-electrode contacts, which is engineered in experiments

[en] The JLab 12 GeV upgrade with a proposed solenoid detector and the CLAS12 detector can provide the granularity and three-dimensional kinematic coverage in longitudinal and transverse momentum, 0.1 (le) x (le) 0.5, 0.3 (le) z (le) 0.7 with P_T (le) 1.5 GeV to precisely measure the leading twist chiral-odd and T-odd quark distribution and fragmentation functions in SIDIS. The large x experimental reach of these detectors with a 12 GeV CEBAF at JLab makes it ideal to obtain precise data on the valence-dominated transversity distribution function and to access the tensor charge

[en] Plasma generated vacuum ultraviolet (VUV) in diffusion plasma excited by a microwave surface wave has been studied by using dielectric-based VUV sensors. Evolution of plasma VUV in the diffusion plasma as a function of the distance from the power coupling surface is investigated. Experimental results have indicated that the energy and spatial distributions of plasma VUV are mainly controlled by the energy distribution functions of the plasma electrons, i.e., electron energy distribution functions (EEDFs). The study implies that by designing EEDF of plasma, one could be able to tailor plasma VUV in different applications such as in dielectric etching or photo resist smoothing

[en] Mechanical properties of individual InAs nanowires (NWs) synthesized by metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) methods are studied by in-situ tensile tests in a scanning electron microscope and their fracture strength and Young's modulus are obtained. The two types of NWs both exhibit brittle fracture with a maximum elastic strain up to ∼10%. Their fracture strength distributes in a similar range of ∼2–5 GPa with a general trend of increasing with NW volume decrease, which is well described by Weibull statistic with a smaller Weibull modulus and a higher characteristic strength for MOCVD NWs. Young's modulus is determined to be 16–78 GPa with an average value of 45 GPa and no dependence on NW diameter for MOCVD NWs and 34–79 GPa with an average value of 58 GPa for MBE NWs