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Presents information on a study of heteroepitaxial ternary cobalt(Co)...yttrium(Y)...silicon(Si)... silicide formed by Co implantation into YSi...Si. Use of metal silicides in microelectronics; Application of Rutherford backscattering; Use of x-ray diffraction to determine compounds present in the sample.

The low-frequency optical absorption properties of graphene nanoribbons in a composite magnetic field are investigated by using the gradient approximation. The spectral function exhibits symmetric delta-function like prominent peaks structure in a uniform magnetic field, and changes to asymmetric square-root divergent peaks structure when subjecting to a composite field. These asymmetric divergent peaks can be further classified into principal and secondary peaks. The spectral intensity and frequency of the absorption peaks depend sensitively on the strength and modulation period of the composite field. The transition channels of the absorption peaks are also analyzed. There exists an optical selection rule which is caused by the orthogonal properties of the sublattice wave functions. The evolution of the spectral frequency of the absorption peaks with the field strength is explored. [ABSTRACT FROM AUTHOR]

Abstract: The in-plane orientation of epitaxial ZnO thin film on Al2O3(0001) was determined by azimuthal scan of X-ray diffraction. Comprehensive structural characterizations, including the lattice strain in perpendicular direction, the defect density, were obtained from high resolution X-ray diffraction. It''s found that a 30° rotation in ZnO against Al2O3, resulting in ZnO〈11 2 0〉//Al2O3〈10 1 0〉, can efficiently reduce the strain and defects in ZnO layer. Consequently, the optical property is significantly improved. [Copyright &y& Elsevier]

Abstract: High-quality AlInGaN quaternary layers were grown on c-Al2O3 using a thick GaN template. A full width at half maximum of 0.075° from AlInGaN(0004) rocking curve and a minimum yield of 5.6% from Rutherford backscattering/channelling spectrometry (RBS) prove the AlInGaN layer of a comparable crystalline quality with GaN layers. The chemical compositions (both of Al and In contents) of AlInGaN layers are directly obtained from RBS and elastic recoil detection analysis. The lattice parameters both in perpendicular and parallel directions are deduced from X-ray diffraction. The AlInGaN layer is found to process a compressive strain in parallel direction and a tensile strain in perpendicular direction. [Copyright &y& Elsevier]

Abstract: We report on structural characterization of AlGaN/GaN superlattices grown on sapphire. The superlattice formation is evidenced by high-resolution x-ray diffraction and transmission electron microscopy. The high resolution x-ray diffraction spectra exhibit a pattern of satellite peaks. The in-plane lattice constants of the superlattices indicate the coherent growth of the AlGaN layer onto GaN. The average Al composition in the superlattices is determined to be 0.08 by Rutherford backscattering spectroscopy. The average parallel and perpendicular elastic strains for the SLs are determined to be and . [Copyright &y& Elsevier]

Abstract: Rutherford backscattering/channeling (RBS/C) and X-ray diffraction (XRD) are used to comprehensively characterize a heterostructure of AlInGaN/GaN/ Al2O3(0001). The AlInGaN quaternary layer was revealed to process a high crystalline quality with a minimum yield of 1.4% from RBS/C measurements. The channeling spectrum of exhibits higher dechanneling than that of at the interface of AlInGaN/GaN. XRD measurements prove a coherent growth of AlInGaN on the GaN template layer. Combining RBS/C and XRD measurements, we found that the interface of GaN/ Al2O3 is a nucleation layer, composed of a large amount of disorders and cubic GaN slabs, while the interface of AlInGaN/GaN is free of extra disordering (i.e. compare with the GaN layer). The conclusion is further evidenced by transmission electron microscopy (TEM). [Copyright &y& Elsevier]

Abstract: The strain state of 570nm AlxGa1-xN layers grown on 600nm GaN template by metal organic chemical vapor deposition was studied using Rutherford backscattering (RBS)/channeling and triple-axis X-ray diffraction measurements. The results showed that the degree of relaxation (R) of AlxGa1-xN layers increased almost linearly when and reached to 70% when . Above 0.42, the value of R varied slowly and AlxGa1-xN layers almost full relaxed when (AlN). In this work the underlying GaN layer was in compressive strain, which resulted in the reduction of lattice misfit between GaN and AlxGa1-xN, and a 570nm AlxGa1-xN layer with the composition of about 0.16 might be grown on GaN coherently from the extrapolation. The different shape of (0004) diffraction peak was discussed to be related to the relaxation. [Copyright &y& Elsevier]

In this paper, an approach to determine the average In composition in InGaN/GaN multiple quantum wells (MQWs) was suggested. The period thickness and the average lattice constants (〈aepi〉 and 〈cepi〉) of MQWs were calculated from high-resolution X-ray diffraction (HRXRD). Then by applying the Vegard''s law, the average In composition 〈x〉 was simultaneously determined by considering the relationship between the lattice constants under strain. At the same time, by using the period thickness, the average In composition was obtained from the simulation of the Rutherford backscattering spectroscopy (RBS). The results obtained from the two techniques are agreeable. So the approach of combining both HRXRD and RBS can tell reliable chemical composition in InGaN/GaN MQWs. [Copyright &y& Elsevier]

The objective of this study was to examine the effects of follicular cells on the in vitro development of porcine preantral follicles. In Experiment 1, one preantral follicle alone (Trt 1) was cocultured with a follicle of the same size with oocytes (Trt 2) or without oocytes (Trt 3). Preantral follicles cultured alone in vitro for 12 days had greater follicle diameters (1017±96 μm versus 706±69 or 793±72 μm, P<0.05), growth rates (201±0.3 versus 103±0.2 or 128±0.2, P<0.05) and oocyte survival rates (73% versus 48, or 25%, P<0.05) than other groups. The inhibitory effects of follicle cells on the growth of preantral follicles and oocyte survival rates were not enhanced by the addition of oocytectomized preantral follicles (Experiment 2). Follicles were cocultured with different sources of follicular cells in other experiments. Coculture with cumulus cells enhanced oocyte survival compared to the control (without coculture) and mural follicular cell groups (Experiment 3). The growth and survival rates of oocytes collected from the group of follicles cocultured with cumulus cells from large antral follicles (>3 mm) were greater (P<0.05) than those from small antral follicles (<3 mm), or than the control group (without cumulus cells, experiment 4). No significant differences in the follicular diameters (674±30 μm versus 638±33 and 655±28 μm) and growth rate (105% versus 94 and 105%) were observed among the preantral follicles of the different treatments (P>0.05). Taken together, coculture with the cells from large antral follicles (>3 mm) exerted a significant positive effect on oocyte survival. The growth and oocyte survival of preantral follicle cocultured with the same size of follicles (with or without oocyte) were inhibited. Growth and survival rates of preantral follicles and oocytes are improved by coculturing them with the cumulus cells derived from larger antral follicles. [Copyright &y& Elsevier]

Discusses efforts to grow an indium gallium nitride (InGaN) layer by metalorganic chemical vapor deposition on sapphire (0001) substrate using a thick GaN intermediate layer. In composition determined by Rutherford backscattering; Perpendicular and parallel elastic strain of the layer; Interatomic spacing between GaN and InN; Symmetric x-ray diffraction measurements.

Examines the formation of GdSi[sub 1.7] layer by channeled ion-beam synthesis. Properties of the formed GdSi[sub 1.7]; Selection of the implanted atoms by the magnetic field of isotope separator; Transformation of the hexagonal GdSi[sub 1.7] phase into the orthorhombic GdSi[sub 2] phase.

Examines the significance of channeled implantation in the synthesis of erbium silicide layers. Range of temperatures and energy used in the deposition; Formation of good crystalline quality of the continuous epitaxial erbium silicide layer; Energy level of ion beam synthesis.

Examines the synthesis of well-separated buried and surface silicide layers using single ion implantation. Ni distribution in silicide; Use of Auger electron spectroscopy and transmission electron microscopy; Dependence of backscattering spectra on implantation sequence.

To investigate the feasibility in predicting the pathological complete pathological response (pCR) of esophageal tumors after neoadjuvant concurrent chemoradiotherapy (CCRT) using pretreatment 18-fluorodeoxyglucose positron emission tomography (FDG PET) images. This study retrospectively included 60 esophageal tumors of 59 patients from November 2012 to August 2021. All patients received neoadjuvant CCRT followed by radical surgery. The FDG PET examination before CCRT was used for evaluation. First, the maximum standardized uptake value (SUVmax) within a tumor was identified and then utilized to form a metabolic tumor volume (MTV) by grouping a set of voxels connecting to the SUVmax and with SUV not less than SUVmax * 0.5. Next, the texture indices were further calculated to describe the heterogeneity of the FDG uptakes discretized as gray level (GL) within MTV. Finally, receiver operating characteristic (ROC) curves analysis assessed the predictive performance of each index. In the analysis, pCR was defined as a positive event. Fifty-seven out of 59 patients were men (57/59, 96.6%). The number of tumors located at the upper, middle, and lower third of the esophagus were 9, 12, and 39, respectively. Ninety-five percent of the tumors were squamous cell carcinomas (57/60, 95%). Seventeen tumors of 17 patients were proved as pCR (17/60, 28.3%). The Chi-square test demonstrated that the associations between treatment response (pCR and non-pCR) and tumor location, clinical T, and N stage were insignificant (p=.16,.193, and.254). The SUVmax demonstrated a significant ability in identifying pCR tumors (AUC=.694, p=.013), whereas MTV was nonsignificant. The tumors with high metabolic uptake corresponded to a high probability of pCR. The texture indices, including GL nonuniformity normalized, low GL zone emphasis, and small area low GL emphasis of zones, GL nonuniformity normalized, long run low GL emphasis, low GL run emphasis, and short run low GL emphasis of runs, and low GL emphasis and small dependence low GL emphasis of GL dependencies, exhibited a significant ability to differentiate pCR from non-pCR tumors (AUC=.331,.289,.298,.339,.311,.311,.316,.312, and.302). These texture indices reflected that a low evaluation corresponded to a high likelihood of pCR. The tumors with a low or low uptake associated with small areas demonstrated a high probability of non-pCR. This study revealed that pCR for esophageal cancer tumors could be predicted using metabolic and texture indices. Future studies are warranted for clinical application. [ABSTRACT FROM AUTHOR]

By injecting cryogenic deuterium pellets into H-mode plasmas with edge localized modes (ELMs) from the low-field side (LFS) on EAST tokamak, the impact of these pellets on the edge plasma can be investigated. In some cases of pellet injection (PI), the intermediate phase (I-phase), i.e, the dithering-like cycles, have been observed. Experiments show that during one dithering-like cycle, three phases can be distinguished, which are closely related to the variations in the pedestal density profiles and density gradient after PI. Phase 1 is characterized by rapid particle loss and a density pedestal crash, phase 2 has a relatively low density gradient and enhanced edge density fluctuation and phase 3 corresponds to the relatively fast recovery of the density pedestal and reduced edge density fluctuation. Through an experimental analysis, it is shown that the plasma will enter the I-phase when the edge line-averaged density increases beyond a certain threshold value after PI. H-I-H transitions are more likely to be observed when the edge line-averaged density is greater than the core line-averaged density. [ABSTRACT FROM AUTHOR]

Examines the implantation temperature dependent distribution of nickel silicide layers formed by ion implantation in silicon. Formation of precipitates; Evolution of an epitaxial silicide surface layer.

The density pedestal structures in a series of type-I ELMy H-mode discharges (0.6 MA/2.5 T) with upper single null (USN) divertor configuration have been studied in EAST. To obtain the pedestal width, density profiles are fitted via the modified hyperbolic tangent (mtanh) function and the two-line method. The pedestal widths from these two methods have a similar tendency. Significant impacts of pedestal poloidal beta and pedestal collisionality on the density pedestal width have been observed for the first time in EAST. The non-linear regressions suggest the density width scaling in type-I ELMy EAST plasma are w ne ∝ c (ν ped ⁎) 0.27 − 0.33 ⋅ (β p , ped ) 0.5 − 0.58. The density fluctuations in the bottom of the pedestal from the fluctuation reflectometry imply an enhanced density fluctuation (P fluc) and an obvious spectral broadening in the high collisionality regime of ν ped ⁎ ≥ 3. The experimental results suggest that the pedestal turbulence would play an important role in the evolution of the pedestal structure. [ABSTRACT FROM AUTHOR]

Long-pulse high β N operation scenario with internal transport barrier (ITB) and central flat q profile has been achieved on EAST. Analysis shows that higher heating power is needed to obtain ITBs in higher density discharges. Analysis of EAST high β N experiments shows that fishbone activities are accompanied with formation ITB and high performance. Experimental and simulation analysis demonstrates that the increasing E x B shear flow by the neutral beam injection (NBI) is important for the formation of ion temperature ITB (Ti-ITB). And, Ti-ITB disappears with the reduction of plasma rotation. While ITBs in channels of electron density (n e) and temperature (Te) are not achieved until fishbone activities are observed, which means that E x B shear flow mainly affects the formation of Ti-ITB in EAST high β N experiments. Experimental analysis shows that the fishbone is accompanied by the increasing E x B shear flow, leading to the formation of Ti-ITBs. A possible explanation for the formation of ITBs in all channels is that fishbone activities in high β N discharges with central flat q-profiles (closed to unity) induce the feedback process of the formation of ITBs, and leading to the increase of E x B shear flow as well as the formation and sustainment of ITBs. • Formation and sustainment of ITBs in high β N discharges with different electron density on EAST tokamak are discussed. • Relationship between fishbone activities and formation of ITBs are demonstrated. • Experimental and simulation analysis are carried out to study the effect of E x B shear flow on the formation of Ti-ITBs. • Role of fishbone activities on the formation of ITBs are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Rutherford backscattering and channeling is combined with X-ray diffraction to study the depth dependence of crystalline quality in InN layers grown by metalorganic chemical vapor deposition on sapphire substrate. The poorest crystalline quality in InN layer is produced at the intermediate region over 100 nm away from the InN/sapphire interface. With increasing layer thickness the crystalline quality improves to a certain degree dependent on the growth temperature. The InN sample grown at 450 °C is found to be more homogeneous than the sample grown at 550 °C. The difference in the defect profile is explained by the temperature-dependent growth modes. The inhomogeneity of structural quality and related properties such as carrier concentration and strain field is possibly the reason to observe a high energy wing in PL spectrum of the InN sample grown at 550 °C. [Copyright &y& Elsevier]

Abstract: Four etching solutions used on support materials and two coating methods of TiO2 were conducted to investigate the effects of catalytical preparing methods on the photocatalysis of 2,2′,3,4,4′,5′-hexachlorobiphenyl (PCB congener 138). The results of XRD analyses confirmed that various etching solutions used on support substrates did not influence the characteristics of titanium(IV) oxide. The XRD patterns of crystallization for the catalysts before and after purification remained unchanged. Hydrofluoric acid used as an etching solution for the support substrates provided the best adhesion stability for the catalysts that demonstrated the highest photocatalytic efficiency for congener 138. Xenon and ultraviolet lamps were used to compare the irradiation effect on photocatalysis. The shortest half-lives of congener 138 were 7.4 and 12.2h using xenon and UV reactors, respectively. Lower chlorinated biphenyls (lower congener numbers) were identified through the continuous dechlorination of congener 138. PCB congeners 99, 87, 66, 49, 28, 17, 9, and 7 were detected as a result of dechlorination from higher chlorinated congeners to lower chlorinated congeners along with the extension of exposure times. The concentrations of chloride ion were increased with increasing exposure time through dechlorination, while the concentrations of organic chlorine of congener 138 were decreased. Meta-dechlorination was the most commonly found mechanism for the photocatalysis of PCB 138. The activation energy of the photocatalysis of congener 138 was 70.8kJmol−1. [Copyright &y& Elsevier]

The reflectometry diagnostics on experimental advanced superconducting tokamak (EAST) are composed of Q-band (32–56 GHz), V-band (48–76 GHz) and W-band (72–110 GHz) microwave reflectometers with X-mode polarization. The three reflectometers with separate frequency bands were launched independently in previous experiments and now are combined together by applying advanced microwave technology. A quasi-optical (QO) combiner/de-combiner by using frequency selective surfaces (FSSs) has been built to combine the three bands so that these waves (32–110 GHz) can be transmitted to the antenna by using one single oversized waveguide. Two double-ridged horns are used for launcher and receiver. The received waves are decoupled by using a QO de-combiner, the same with the combiner. The designed parameters and laboratory test results of the upgraded system have been presented. The density pedestal evolution during the edge localized modes (ELMs) in EAST plasma have been presented as an example for the application of the updated reflectometers. [ABSTRACT FROM AUTHOR]

We report a direct observation of quantum dots formed spontaneously in a thick InGaN epilayer by high resolution transmission electron microscopy. Investigation of a (280 nm thick) In[sub 0.22]Ga[sub 0.78]N single layer, emitting in the blue/green spectral region, reveals quantum dots with estimated sizes in the range of 1.5-3 nm. Such sizes are in very good agreement with calculations based on the luminescence spectra of this specimen. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]