Comparison of hydrogen isotope retention and irradiation damage behaviors in tungsten and SS-316 with simultaneous C+–D2+ implantation

Behaviors of hydrogen isotope retention and damages in tungsten and SS-316 with simultaneous C⁺–D₂⁺ implantation were compared to those with only D₂⁺ implantation using X-ray photoelectron spectroscopy (XPS), Thermal desorption spectroscopy (TDS), glow discharge-optical emission spectroscopy (GD-OES) and Transmission electron microscopy (TEM).The total D retention for SS-316 with only D₂⁺ implantation was about 45% as large as that for tungsten. The D retention for simultaneous C⁺–D₂⁺ implanted tungsten and SS-316 clearly increased as a factor of 1.7, which is almost the same among these samples. The density of dislocation loops was enhanced by the simultaneous C⁺–D₂⁺ implantation, indicating the D trapping site would be produced by C⁺ implantation. As for the D desorption temperature, small shift toward lower temperature side was found for SS-316 compared to tungsten, indicating the D trapping energy by dislocation loops and grain boundary for SS-316 is lower than that for tungsten.     

Electronic structure of fullerene derivatives in organic photovoltaics

The electronic structures of the fullerene derivatives [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM), [6,6]-diphenyl C₆₂ bis (butyric acid methyl ester) (bisPCBM), C₇₀, [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₀BM), [6,6]-phenyl-C₆₁-butyric acid butyl ester (PCBB), [6,6]-phenyl-C₆₁-butyric acid octyl ester (PCBO), [6,6]-thienyl-C₆₁-butyric acid methyl ester (TCBM), and indene-C₆₀ bisadduct (ICBA), which are frequently used as n-type materials in organic photovoltaics, were studied by ultraviolet photoelectron spectroscopy and inverse photoemission spectroscopy. We also performed molecular orbital calculation based on density functional theory to understand the experimental results. The electronic structures near the energy gap of the compounds were found to be governed predominately by the fullerene backbone. The side chains also affected the electronic structures of the compounds. The ionization energy and electron affinity were strongly affected by the number of carbons and functional groups in the side chain.     

Innovationen durch PACVD Duplex Schichtsysteme im Leichtmetall‐Druckguss

Innovative PACVD Duplex Layer Systems applied for the Light Metal Die Casting Process Duplex‐PACVD hard coatings are well‐known for increasing the tool performance in terms of adhesion, wear, fatigue, and corrosion resistance of the steel. The developments made in synthesizing duplex nanostructure and nanocomposite, mono and gradient layers based on borides are described. The aim of the investigation is to optimize the surface capability by plasma process combinations: duplex process, gradient‐layer. Within this work different types of duplex hard coatings produced by PACVD were investigated in terms of their tribological behavior and were tested in aluminum and magnesium die casting applications. Practical tests have been carried out by automobile producers and part suppliers. All coatings tested on die casting tools showed a significant increase of lifetime and a reduced metal adhesion tendency. The economic efficiency of coated die casting tools could be proved.     

Bacillus thuringiensis and its pesticidal crystal proteins

During the past decade the pesticidal bacterium Bacillus thuringiensis has been the subject of intensive research. These efforts have yielded considerable data about the complex relationships between the structure, mechanism of action, and genetics of the organism's pesticidal crystal proteins, and a coherent picture of these relationships is beginning to emerge. Other studies have focused on the ecological role of the B. thuringiensis crystal proteins, their performance in agricultural and other natural settings, and the evolution of resistance mechanisms in target pests. Armed with this knowledge base and with the tools of modern biotechnology, researchers are now reporting promising results in engineering more-useful toxins and formulations, in creating transgenic plants that express pesticidal activity, and in constructing integrated management strategies to insure that these products are utilized with maximum efficiency and benefit.     

Mining of Moving Objects from Time-Series Images and its Application to Satellite Weather Imagery

The framework of mining of moving objects from image data sequence is presented. Scenes are first clustered and labeled by using two-stage SOM that is modified to recognize images including similar moving objects as the same cluster, and that well recognizes scenes including prominent objects. After extraction of images which include prominent objects based on clustering result, the position and the shape of objects are approximated by using mixture gaussian model via EM algorithm, providing the adequate or larger number of components. By adopting the average of the data points in the smaller blocks as the initial parameters, the solutions are stabilized and the identification of components among time-series images and the tracking of a specific object become easier.This framework is applied to a four-year (ranging from 1997 to 2000) dataset of cloud images taken by Japanese weather satellite GMS-5 to evaluate its performance. Modified SOM method well classifies scenes which include prominent moving object, and seasonal variation tendency is detected in the cluster ID sequence. The result of object detection via EM algorithm for summer-type images including clear cloud masses such as typhoons shows that this approach well approximate the adequate distribution of cloud masses in many cases. Objects in the very irregular shapes are also well represented as the mixtures of gaussians.The extracted object information, together with the scene clustering result, is expected to offer us a rich source for knowledge discovery of video datasets. This approach is one of the effective ways of mining video images whose characteristics are unknown in advance, and thus applicable to the various type of applications.     

Development of a three-dimensional magnetohydrodynamics code for electromagnetic pumps

Annular linear induction pumps (ALIPs) are one of the electromagnetic (EM) pumps, which drive liquid metal using EM force, for fast reactors and have been developed in many countries. An ALIP mainly consists of multiple coils, iron cores and an annular flow channel. We have calculated the developed pressure of ALIPs using a two-dimensional magnetohydrodynamics (MHD) code. There are some reports in which pressure drop and fluctuation were observed in EM pump operations near the top of the pressure and flow rate relation (P–Q) curve. For fear of this phenomenon, the EM pump design is sometimes too conservative. To simulate the pressure drop and fluctuation occurrence conditions, we have developed a new three-dimensional (3D) MHD code. Clarification of this condition and its phenomena in the sodium flow will enable design of a new structure or determination of operation conditions that preclude this pressure drop and fluctuation and, thereby, achieve high efficiency. In this paper, the model of our new 3D MHD code, the accuracy of the code, simulation results focusing on pressure drop and fluctuation by radial and circumferential vortices are reported.     

The Roles of the Ge‐Te Core Network and the Sb‐Te Pseudo Network During Rapid Nucleation‐Dominated Crystallization of Amorphous Ge2Sb2Te5

Ge₂Sb₂Te₅ (GST) has demonstrated its outstanding importance among rapid phase‐change (PC) materials, being applied for optical and electrical data storage for over three decades. The mechanism of nanosecond phase change in GST, which is vital for its application, has long been disputed: various, quite diverse scenarios have been proposed on the basis of various experimental and theoretical approaches. Nevertheless, one central question still remains unanswered: why is amorphous GST stable at room temperature for long time while it can rapidly transform to the crystalline phase at high temperature? Here it is revealed for the first time, by modelling the amorphous structure based on synchrotron radiation anomalous X‐ray scattering data, that germanium and tellurium atoms form a “core” Ge‐Te network with ring formation. It is also suggested that the Ge‐Te network can stabilize the amorphous phase at room temperature and can persist in the crystalline phase. On the other hand, antimony does not contribute to ring formation but constitutes a “pseudo” network with tellurium, in which the characteristic Sb–Te distance is somewhat longer than the covalent Sb–Te bond distance. This suggests that the Sb‐Te pseudo network may act as a precursor to forming critical nuclei during the crystallization process. The findings conclude that the Ge‐Te core network is responsible for the outstanding stability and rapid phase change of the amorphous phase while the Sb‐Te pseudo network is responsible for triggering critical nucleation.     

线损电价测算中线损率计算方法的探讨

阐述了统计线损率与电压累计线损率的概念及两者的差别,运用典型的电网图举例说明了各电压等级统计线损率和电压累计线损率的计算方法,介绍了通过各电压等级统计线损率及一些辅助参数计算电压累计线损率的方法,解决了线损电价测算中电压累计线损率的计算问题,并针对各电压等级不同的情况提出了修正建议;最后通过计算实例验证了这种方法的实用性.     

Surface crystallization and second-order optical non-linearity in Gd2O3–Bi2O3–B2O3 glasses

Some ternary Gd₂O₃–Bi₂O₃–B₂O₃ glasses are prepared, and crystallization behavior and second harmonic intensity are examined to develop new non-linear optical crystallized glasses. The glasses with Gd₂O₃ contents of 8–14 mol% have large densities of over 6 g/cm³ and large refractive indices of ～ 1.9. Transparent surface crystallized glasses consisting of two kinds of crystalline phases with different morphologies, i.e. plate shape and needle shape crystals, are fabricated by heat-treatment at temperatures between glass transition and crystallization temperatures. From second harmonic generation microscope observations, micro-Raman scattering spectra and XRD analyses, plate shape crystals are determined to be non-linear optical Gd_xBi_1KxBO₃ and needle shape crystals are Bi₃B₅O₁₂ having no second-order optical non-linearity. Since crystallized glasses consisting of Gd_xBi_1KxBO₃ crystals exhibit relatively strong SHGs, they have a high potential for application to light control devices.     

Electronic structure and surface morphology of [6,6]-phenyl-C71-butyric acid methyl ester films

We investigate the electronic structure of [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₀BM) films by ultraviolet photoelectron and inverse photoemission spectroscopy. We discuss the electronic structure of PC₇₀BM in comparison with C₇₀ and [6,6]-phenyl-C₆₁-butyric acid methyl ester (PC₆₀BM). The molecular orbitals around the energy gap of PC₇₀BM are broadly distributed due to the low symmetry of the molecular structure. Consequently, the energy gap of PC₇₀BM is smaller than that of C₇₀ and PC₆₀BM. The film deposition method affects the polarization energy between the PC₇₀BM molecules, and thus affects the electronic structure of the films.