[en] We study the possibility of the scalar charmonium and glueball mixing in e⁺e^- annihilation at √s=10.6 GeV. The effects can be used to explain the unexpected large cross section (12±4 fb) and the anomalous angular distribution (α=-1.1^+0.8_-0.6) of the exclusive e⁺e^-→J/ψχ_c0 process observed by Belle experiments at KEKB. We calculate the helicity amplitudes for the process e⁺e^-→J/ψH(0⁺⁺) in NRQCD, where H(0⁺⁺) is the mixed state. We present a detailed analysis on the total cross section and various angular asymmetries which could be useful to reveal the existence of the scalar glueball state

[en] We investigate the feasibility of probing anomalous top-quark couplings of Wtb, Ztt-bar, and γtt-bar in terms of an effective Lagrangian with dimension-six operators at future e⁺e^- linear colliders with a c. m. energy √s ∼ 500 - 800 GeV. We first examine the constraints on these anomalous couplings from the Z → bb-bar data at LEP I and from unitarity considerations. We then consider in detail the effects of anomalous couplings on tt-bar spin correlations in the top-pair production and decay with three spin bases: the helicity, beamline and off-diagonal bases. Our results show that the polarized beams are more suitable for exploring the effects of different new operators. For polarized beams, the helicity basis yields the best sensitivity. (author)

[en] We investigate the feasibility of probing anomalous top-quark couplings of Wtb, Ztt-bar, and γtt-bar in terms of an effective Lagrangian with dimension-six operators at future e⁺e^- linear colliders with a c.m. energy √(s)∼500-800 GeV. We first examine the constraints on these anomalous couplings from the Z→bb-bar data at CERN LEP I and from unitarity considerations. We then consider in detail the effects of anomalous couplings on tt(bar sign) spin correlations in the top-pair production and decay with three spin bases: the helicity, beamline, and off-diagonal bases. Our results show that the polarized beams are more suitable for exploring the effects of different new operators. For polarized beams, the helicity basis yields the best sensitivity

[en] Metal-oxide-semiconductor capacitors that incorporate ZrO₂ gate dielectrics were fabricated by radio frequency magnetron sputtering. In this work, the essential structures and electrical properties of ZrO₂ thin films were investigated. C-V, energy dispersive x-ray spectrometry, and transmission electron microscopy analyses reveal that an interfacial layer was formed, subsequently reducing the k value of the annealed ZrO₂ thin films. Additionally, the mechanisms of conduction of the Al/ZrO₂/p-Si metal/zirconium oxide/semiconductor structure were studied with reference to plots of standard Schottky emission, modified Schottky emission, and Poole-Frenkel emission. According to those results, the dominant mechanisms at high temperatures (>425 K) are Poole-Frenkel emission and Schottky emission in low electric fields (<0.6 MV/cm) and high electric fields (>1 MV/cm), respectively. Experimental results indicate that the Al/ZrO₂ barrier height is 0.92 eV and the extracted trap level is about 1.1 eV from the conduction band of ZrO₂. The modified Schottky emission can be applied in an electric field to ensure that the electronic mean free path of the insulator is less than its thickness. According to the modified Schottky emission model, the extracted electronic mobility of ZrO₂ thin films is around 13 cm²/V s at 475 K. The mean free path of transported electrons in ZrO₂ thin films is between 16.2 and 17.4 nm at high temperatures (425-∼475 K)

[en] Advanced hepatocelluar carcinoma (HCC) with invasion of venous systems usually indicates not only a poor prognosis but also a contraindication for transcatheter arterial chemoembolization (TACE). This study evaluated the feasibility of TACE for advanced HCC with inferior vena cava (IVC) and right atrium (RA) tumors and, also, to search for the ideal embolization particle size. Twenty-six patients who had HCC invasion into the IVC included five patients with coexistent RA tumors that were treated with TACE. The chemoembolization method was cisplatin, doxorubicin, and mitomycin C mixed with Lipiodol and Ivalon. The selection of Ivalon particles was divided into two groups based on their size: (A) >180 μm, N = 9; and (B) 47-180 μm, N = 17. The overall response rate was 53.8% (14/26). Based on the response to TACE, the median survival period of the entire group was 4.2 months (range, 1.5 to 76.7 months). The median survival period of the 14 responders was 13.5 months (1.5-76.7 months), and that of the 12 nonresponders, 3.3 months (2.1 to 24.3 months) (p < 0.002). Comparing the two Ivalon particle sizes, the response rate was 12.5% (1/9 patients) for group A and 76.5% for group B (13/17 patients) (p < 0.02). No serious complication was observed post-chemoembolization. In conclusion, TACE is a safe and effective treatment for advanced HCC with IVC and RA tumors, and small Ivalon particles (47-180 μm) are superior to large ones (>180 μm).

[en] We have successfully synthesized flower-like gold nanomaterials and Fe₃O₄/Au composite nanomaterials through the use of wet chemical methods in aqueous solution. In the presence of 0.5 mM citrate, 0.313 mM poly(ethylene glycol), and 109.72 mM sodium acetate (NaOAc), we prepared Au nanoflowers (NFs) having diameters ranging from 300 to 400 nm in aqueous solution after the reduction of Au ions at room temperature for 10 min. In the presence of spherical Fe₃O₄ nanomaterials, we applied a similar synthetic method to prepare Fe₃O₄/Au composite nanomaterials, including nanowires (NWs) that have a length of 1.58 μm and a width of 28.3 nm. We conducted energy-dispersive x-ray analysis, scanning electron microscopy, transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, and x-ray powder diffraction measurements to characterize the as-prepared flower-like Au nanomaterials and Fe₃O₄/Au composite nanomaterials. From time-evolution TEM measurements, we suggested that Au atoms that were bound to the Fe₃O₄ nanomaterials grew to form Fe₃O₄/Au composite nanomaterials. The as-prepared Au NFs absorbed light strongly in the visible-near-infrared (Vis-NIR) region (500-1200 nm). The Fe₃O₄/Au composite nanomaterials had electronic conductivities greater than 100 nA at an applied voltage of 20 mV, which induced a temperature increase of 20.5 ± 0.5 deg. C under an alternating magnetic field (62 μT)

[en] Inclusive J/ψ production in e⁺e^- annihilation is studied in the framework of NRQCD. We first review the leading-order calculations of the cross sections for e⁺e^-→J/ψcc-bar and e⁺e^-→J/ψgg and find that their ratio is about 1:1.5 at √(s)≅10 GeV. This result is in conflict with the current measurements by the Belle Collaboration, which finds that the process e⁺e^-→J/ψcc-bar accounts for about 2/3 of all the prompt J/ψ's. We find that the discrepancy problems in the total rate as well as in the J/ψ momentum distributions can be resolved by postulating a large renormalization K factor (K≅4) for the J/ψcc-bar cross section and by taking into account collinear suppression in the end-point energy region of J/ψgg production. Detailed studies of the model predictions in terms of the density matrix are performed and various momentum and angular distributions are presented as functions of the K factors. These distributions can be used to determine the normalizations of each subprocess provided that the production and decay angular distributions do not alter much by higher-order corrections

[en] We consider a general effective Lagrangian for couplings of a Higgs boson to the top quark to dimension-six operators including CP violation effects. Constraints on some of them are derived from the Z→bb(bar sign) data. We study the process e⁺e^-→tt(bar sign)H to probe the nonstandard couplings. We find that at a linear collider with a c.m. energy √(s)∼0.5-1.5 TeV and a high luminosity of 10-1000 fb^-1, these non-standard couplings may be sensitively probed. (c) 1999 The American Physical Society