[en] A prospective study was performed in 114 patients with suspected acute myocardial infarction using planar ¹¹¹In-antimyosin imaging. A ratio of maximum myocardial uptake counts (H) (9x9 pixels) over adjacent lung background (L), i.e. H/L ratio, was obtained from 24 and 48 h images. This value was compared with peak creatine kinase (CK) enzyme and left ventricular ejection fraction (LVEF). There was good correlation between the H/L ratio and CK (r=0.76, P<0.0001) and moderate correlation with ejection fraction (r=-0.44, P<0.0001). This simple quantitative method may be useful for detection of acute myocardial infarction and for quantification of the extent of necrosis. (author)

[en] Amorphous silicon nitride (a-SiN_x) films were prepared by low pressure chemical vapor deposition from SiHCl₃(Trichlorosilane, TCS)-NH₃-N₂ system to obtain stoichiometric film with low hydrogen content. The growth kinetics was investigated as a function of total pressure, NH₃/TCS flow ratio and deposition temperature. The film compositions and topography were characterized by X-ray photoelectron spectroscopy, Auger depth profile, Fourier transform infrared spectroscopy, elastic recoil detection and atomic force microscopy, respectively. The growth rate of the films follows an Arrhenius behavior with apparent activation energy of 171 kJ mol^-1 between 730 and 830 deg. C. At lower NH₃/TCS flow rate ratios, silicon-rich a-SiN_x films were obtained while all deposits were stoichiometric with a N/Si atomic ratio of approximately 1.30-1.33 as the ratios is higher. The hydrogen content of the prepared a-SiN_x films is 1.2 at.% that is approximately 15 times lower than those of traditional PECVD films and approximately three times lower than those of previous LPCVD films using silane or dichlorosilane and ammonia. The surface topography of the prepared film is smooth and uniform with a root mean square roughness value of 0.47 nm

[en] A previous study shows that the two-row fuel assembly has much more favorable neutron-physical and thermal-hydraulic behaviour than the conventional one-row fuel assemblies. Based on the new developed two-row fuel assembly, an SCWR core is proposed and analyzed. The core contains 249 fissile fuel assemblies in the inner zone and 52 reflector assemblies in the peripheral area. The inner zone has fissile assemblies of different enrichments, to flatten the radial power profile. The total core thermal power is 3500 MW, and the average linear power density is 19 kW/m. The performance of the proposed core is investigated with 3-D coupled neutron-physical and thermal-hydraulic core calculations. During the coupling procedure, the thermal-hydraulic behaviour is analyzed using a sub-channel analysis code and the neutron-physical performance is computed with a 3-D diffusion code. This paper presents the main results achieved so far related to the distribution of some neutronic and thermal-hydraulic parameters. It shows that with adjustment of coolant and moderator mass flow in different assemblies, both optimized neutron-physical and thermal-hydraulic behaviour of the SCWR core is achieved. A sensitivity study of some important parameters (e.g. heat transfer correlation) is carried out. (authors)

[en] An efficient catalytic system consisting of H₂O, Polyaluminium chloride (PAC) and Tetrabutylammonium bromide (TBAB) was applied to the cycloaddition of carbon dioxide (CO₂) to epoxides under mild conditions. Their catalytic cycloaddition activities were found to be well correlated with H₂O and polyaluminium chloride, which had a synergetic effect with the halide anion of TBAB. The presence of H₂O and PAC could remarkably improve the yield of propylene carbonate (PC) by which the reaction yield is about 4-5 times higher than TBAB. alone.The catalytic system also exhibited excellent cycloaddition activities for various epoxide substrates. (paper)

[en] The SCWR core concept SCWR-Mis proposed based on a mixed spectrum and consists of a thermal zone and a fast zone. This core design combines the merits of both thermal and fast SCWR cores, and minimizes their shortcomings. In the thermal zone co-current flow mode is applied with an exit temperature slightly over the pseudo-critical point. The downward flow in the thermal fuel assembly will provide an effective cooling of the fuel rods. In the forthcoming fast zone, a sufficiently large negative coolant void reactivity coefficient and high conversion ratio can be achieved by the axial multi-layer arrangement of fuel rods. Due to the high coolant inlet temperature over the pseudo-critical point, the heat transfer deterioration phenomenon will be eliminated in this fast spectrum zone. And the low water density in the fast zone enables a hard neutron spectrum, also with a wide lattice structure, which minimizes the effect of non-uniformity of the circumferential heat transfer and reduces the cladding peak temperature.The performance of the proposed core, including the neutron-physical and thermal-hydraulic behavior in sub-channel scale, is investigated with coupled neutron-physical/thermal-hydraulic simulation tools, which at the same time enables multi-scale analysis. During the coupling procedure, the thermal-hydraulic behavior is analyzed using a multi-channel code and the neutron-physical performance is computed with a 3-D diffusion code. Based on the core results, the pin-power reconstruction is carried out for each fuel assembly to predict the local pin-power distribution. Moreover, the sub-channel calculation is performed to obtain the thermal hydraulic parameters in each sub-channels and fuel rods. Based on the coupled analysis, measures to improve the performance of the SCWR-M core design are proposed and evaluated in this paper.The results achieved in this paper have shown that the mixed spectrum SCWR core concept (SCWR-M) is feasible and promising. One reference SCWR-M design is proposed for future analysis. (authors)

[en] Several properties of Al-doped Zn_0.95Co_0.05O thin films prepared by radio frequency (RF) magnetron co-sputtering have been systematically investigated. The experimental results indicate that Co²⁺ steadily substitutes for tetrahedrally coordinated Zn²⁺ in the ZnO wurtzite lattice without any segregated secondary phase formation, and that a trace amount of additional Al doping has a profound influence on the enhancement of electrical and magnetic properties of Co:ZnO films. All the films show room-temperature ferromagnetism, and a giant magnetic moment of 3.36 μ_B/Co is obtained in the Zn_0.948Co_0.05Al_0.002O thin film. The ferromagnetic ordering is seen to be correlated with the structural defects. Moreover, a phenomenon of band gap broadening and absorption edge blueshift can be achieved by additional Al doping into the Co:ZnO films

[en] To evaluate the clinical efficacy of ⁹⁹Tc^m-MIBI myocardial tomography for detecting coronary artery disease (CAD), 115 consecutive patients who underwent both ⁹⁹Tc^m-MIBI single photon emission computed tomography (SPECT) and coronary arteriography were studied. Thirty-three patients without and 82 with significant coronary artery disease were documented by coronary arteriography. The overall sensitivity and specificity of ⁹⁹Tc^m-MIBI SPECT for detecting coronary artery disease were 96 and 87.9%, respectively. The sensitivity for identifying patients with CAD without myocardial infarction was 88%. The sensitivity of ⁹⁹Tc^m-MIBI SPECT for detecting individual coronary artery lesions was 86% for left anterior descending artery (LAD), 69% for left circumflex artery (Lcx) and 86% for right coronary artery (RCA), lesions respectively. In conclusion, ⁹⁹Tc^m-MIBI SPECT provides a reliable method for detecting CAD. (Author)

[en] The annealing effects on the microstructure and magnetic properties of Zn_0.92Co_0.08O films annealed at different temperatures (200, 400 and 600 deg. C) in air and vacuum have been systematically investigated. The as-grown and annealed films are all highly textured with (002) orientation and all show room temperature ferromagnetism. The as-grown film is in a state of compressive stress and the film becomes almost stress-free after an annealing treatment at 400 deg. C in vacuum, while the film annealed at 600 deg. C goes into a state of tension. The magnetic moment increases after annealing in vacuum and decreases after annealing in air at the same temperature, compared with that of as-grown film. Moreover, the magnetic moment increases with the annealing temperature up to 400 deg. C and then shows a rapid decline at an annealing temperature of 600 deg. C in vacuum. The experimental results indicate that the enhancement of ferromagnetism is strongly correlated with the increase in oxygen vacancies and that the existence of interstitial Zn atoms plays an important role in mediating the ferromagnetism in Co-doped ZnO films

[en] γ-AlON:Er³⁺ phosphors with different Er³⁺ concentration for upconversion luminescence were prepared by a combination of carbothermal reduction and nitridation and solid-state synthesis methods. The effect of Er³⁺ content on emission spectra was investigated. Under the excitation of 980 nm diode laser, green emission centered at 548 nm and red emission centered at 666 nm were observed, which are ascribed to the transition of ⁴S_3/2/²H_11/2→⁴I_15/2 and ⁴F_9/2→⁴I_15/2 of Er³⁺ ions, respectively. The pump power dependence indicates a two-photon process involved in the upconversion luminescence. The ratio of red emission relative to green emission was enhanced with the increase in Er³⁺ concentration. The possible mechanisms were discussed.

[en] In the simulation of trans-critical transients of Supercritical water cooled reactor (SCWR), calculation will terminate because of the sudden change in void fraction across the critical point. To solve this problem, a pseudo two-phase method is proposed with a virtual region of latent heat at pseudo-critical temperatures. A smooth variation of void fraction can be realized by using liquid-field conservation equations at temperatures lower than the pseudo-critical temperature, and vapor-field conservation equations at temperatures higher than the pseudo-critical temperature. Using this method, the system code ATHLET is modified to ATHLET-SC mod 2 on the basic of the previous modified version ATHLET-SC by Shanghai Jiao Tong University. The results of tests are verified that the calculation error with the pseudo two-phase method for supercritical fluid is acceptable, when the virtual region of latent heat is kept small. Moreover, the ATHLET-SC mod 2 code is used to simulate the pressurization and depressurization process of a single flow channel with the pressure transition as well as blowdown process. The results indicate a good applicability of the modified code. (author)