[en] Extensive Raman investigations were conducted on a wide range of diamond films whose structures were dilineated by optical and confocal microscopy. The Raman Spectra from one extreme of this range indicates a very intense 1331 cm^-1 line diagnostic of bulk crystalline diamond. Microscopy of the corresponding film shows the presence of many large true diamond crystallite. The 1331 cm^-1 Raman line at the other extreme of the range, however, is virtually absent. It is replaced, at this extreme, by a very broad Raman contour whose maxima occur near 1355 cm^-1 and 1575 cm^-1. Optical microscopy now reveals a complete lack of diamond crystallites. The ratio of the integrated Raman intensity of the 1331 cm^-1 diamond line to the integral of the entire broad contour extending from ∼1200 cm^-1 to 1800 cm^-1, with maxima near 1355 cm^-1 and 1575 cm^-1, was determined. This ratio rises with increasing diamond crystallite size, and it decreases as true diamond crystallites are replaced by diamond-like, but amorphous, hard carbon, which produces the broad Raman contour. The measured intensity ratio was analyzed in terms of a differential equation related to phonon coupling. The increase of the intensity ratio of the 1331 cm^-1 diagnostic diamond peak is due to phono-phonon coupling between the diamond crystallites, as the concentration of the amorphous diamond-like carbon decreases. Confocal microscopy indicates many amorphous-like regions interspersed between diamond crystallites which account for the intensity loss, and agree with the Raman intensity measurements. These Raman measurements crystallinity versus amorphous hard-carbon character of thin diamond film

[en] A total of 168 patients with spinal tumors were evaluated with MRI. The study shows that MRI is a sensitive method for demonstration of spinal tumors. MRI also provides a possibility to separate different histological types of tumors based on their morphology and signal characteristics. Intramedullary tumors (25 cases): Ependymomas (6 cases) and astrocytomas (7 cases) were most common. Ependymomas have a more irregular signal pattern than astrocytomas. Astrocytomas are more common in the upper spine and are more often completely cystic. Contrast enhancement is important for separation of cyst, edema and solid tumor. Intradural extramedullary tumors (31 cases): Neuromas (14 cases) and meningeomas (11 cases) were most common. Neuromas always had markedly increased signal intensity on T2-weighted images. Meningeomas were only hyperintense occasionally. Neuromas were more inhomogeneous than meningeomas on T1-weighted images. Contrast enhancement is valuable for delineation of small tumors. Extradural tumors (91 cases): 76 patients had metastases, 7 primary spinal tumors and 8 multiple myelomas. T1-weighted images are almost always superior to other sequences because tumor invasion in the fatty bone marrow is seen as a low signal area in contrast to the high signal from the fat. Spinal lymphomas (14 cases): May be divided into vertebral, paraspinal and epidural tumors. Most cases have all locations. Spinal neurofibromatosis (7 cases): Most patients had multiple, often bilateral neurofibromas. One patient had a meningeomas on one spinal dysplasia with meningoceles. MRI is superior to other modalities for evaluation of the full extent of the disease. The coronal view is often valuable because of the arrangement of the tumors. In addition to providing diagnosis, MRI is of great value in treatment follow-up

[en] Ab initio band structure calculations have been performed for the spin-orbit interaction effects at the top of the valence bands for GaAs and InSb. Relativistic, norm-conserving pseudopotentials are used with no correction made for the gaps from the local density approximation. The spin-orbit splitting at Γ and linear terms in the /rvec char/k dependence of the splitting are found to be in excellent agreement with existing experiments and previous theoretical results. The effective mass and the cubic splitting terms are also examined. 6 refs., 1 fig., 2 tabs

[en] The electronic energy band structures of the La-doped superconductors TlBa_1.2La_0.8CuO_5+δ were calculated. The effect of the oxygen content on their electronic structures was studied. The results show that compared with those for TlBa₂CuO₅, the La doping at the Ba site results in the moderate change in the band structures and the decrease in the densities of states, but the increase in the oxygen content caused by the La doping results in the great change in the band structures and the densities of states near the Fermi surface. The low oxygen content causes the degree of complexity of the band structures and the densities of states near the Fermi level E_f to increase and the high oxygen content causes them to decrease. The oxygen content plays a dominant role in TlBa_1.2La_0.8CuO_5+δ. In addition, the Cu-O planes are most sensitive to the increase in the oxygen content. 14 refs., 6 figs., 2 tabs

[en] Nano-scale γ-AgI with grain sizes of 7-9 nm was synthesized by quenching molten AgI in liquid nitrogen (LN). The temperature dependence of ionic conductivity of nano-scale γ-AgI was studied by complex impedance measurement. Linear fit for the log σT vs. 1/T curve revealed that the curve was composed of three segments with different slopes, with two kinks at about 147 deg. C and 223 deg. C. The activation energies for the three segments were calculated to be 0.40, 1.61, and 0.12 eV, respectively. The curve reveals a continuous transition between 147 deg. C and 223 deg. C instead of a break at 147 deg. C that occurring in normal AgI, indicating a change from first-order phase transition to a second-order one after AgI was quenched in LN. The room temperature (RT) conductivity of nano-AgI is about two orders of magnitude larger than that of normal AgI. We suggest that the ionic conduction of nano-AgI within temperature ranges of RT to 147 deg. C, 147-223 deg. C, and above 223 deg. C are controlled by grain boundaries and dislocations induced by quenching, formation and diffusion of Frenkel defects inside the grains, and transport of quasi-liquid silver ion, respectively. The second-order phase transition is attributed to lattice deformation and formation of Frenkel defects

[en] Breaking waves and Langmuir circulation are dominant turbulent processes in a wind-driven upper ocean. Surface waves and, in particular, breaking waves can disintegrate an oil film, generating oil droplets or blobs of water-in-oil emulsions when the oil is weathered. Langmuir circulation, with its convergent and divergent flows at the ocean surface, can organize the floating particles into nearly parallel bands aligned in the wind direction. However, the rapid temporal evolution of the circulation makes it an effective mechanism for dispersing particles. In this paper, we estimate horizontal diffusivities of floating particles by examining Lagrangian particle statistics inferred from sonar images of the ocean surface. The diffusivities are in the range of O(10^-3)-O(1) m² s^-1 and depend on the crosswind and downwind velocities in Langmuir circulation. The particle dispersion on the ocean surface is not isotropic. The diffusivity in the crosswind direction is generally larger than that in the downwind direction. (Author)

[en] MoS₂ particles of uniform size (ca. 70 nm) consisting of random and loosely stacked layers have been synthesized from hydrazine solution with (NH₄)₂Mo₃S₁₃ as the precursor at 180 deg. C for 16 h under hydrothermal conditions. The particles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HREM). The influences of reaction conditions are discussed while a mechanism is proposed to explain the formation of this peculiar morphology

[en] Highlights: • Adsorption enthalpy and entropy of oxygen on Zn-term ZnO(0001) were measured by photoreflectance. • These parameters are large in magnitude and vary nonmonotonically with coverage. • Many kinds of sites, chemical species and reconstructions contribute to this behavior. • Entropic and enthalpic contributions to the free energy are comparable near room temperature. - Abstract: The equilibrium behavior of oxygen adsorbed on metal oxide surfaces such as ZnO(0001) often affects their behavior in applications such as gas sensing. The present work attempts to bridge this distinct gap to applications from an alternate perspective by employing the optical technique of photoreflectance (PR) to measure the enthalpy ΔH_a_d_s and entropy ΔS_a_d_s of oxygen adsorption as a function of coverage on Zn-terminated ZnO(0001). The large and strongly coverage-dependent parameters, stemming from a multiplicity of sites, chemical species and reconstructions, lead to a nonmonotonic coverage variation in both ΔH_a_d_s and ΔS_a_d_s. The entropic contribution to the free energy is comparable to the enthalpic contribution even near room temperature, so that temperature effects on oxygen adsorption may be uncommonly large.

[en] The JA-3003 model is a key equipment used for monitoring whole body surface αβγ contamination at nuclear power plant control area.The article introduced its software design. The design is completed using object oriented program language Delphi 5.0

[en] Objective: To study the interrelation between the degree of infection and changes in cellular factors in pediatrics mycoplasma pneumonia patients. Methods: 91 cases of pediatric mycoplasma pneumonia were divided into a serious group and a lighter group according to the serum IgM levels. The fast serum levels of tumor necrosis factor-a (TNF-α) and interleukin-6 (IL-6) were determined with ratio-immunoassay (RIA) in those patients as well as 35 controls. Results: The levels of serum TNF-α and IL-6 in both groups of patients were significantly higher than those in the controls (P < 0.01). The levels in the serious group were also significantly higher than those in the lighter group (P < 0.05). The data in patient groups were analysed with linear correlation. The correlative coefficient of TNF-α was r = 0.49 and that of IL-6 was r = 0.95, Suggesting positive correlation with the seriousness of infection. Conclusion: The cellular factors TNF-α and IL-6 might participate in the whole process of mycoplasma infection and their serum levels were positively correlated with the seriousness of the disease