[en] The influence of exit tip thickness of nozzle δ_e on the flow field and performance of a jet pump was studied numerically in this paper. It is found that δ_e has influence on the distribution of turbulence kinetic energy k. If δ_e is ignored, k takes the highest value but dissipates rapidly than that of nozzle with a certain tip thickness. δ_e also affect apparently the development of tip vortex, which will occur near the exit tip of nozzle. The bigger the δ_e is, the larger the vortex is. The tip vortex develops with the increase of flow rate ratio q. When q=1 and δ_e=0.6∼0.8mm, a small vortex will be found downstream the tip vortex. And a concomitant vortex happens down the tip vortex in the case of q=1 and δ_e=0.8mm. As q increases to 2, the downstream small vortex disappears and the concomitant vortex becomes bigger. It is also found that the tip vortex might interact with the possible backflow that formed in the throat tube and parts of suction chamber. The center of backflow was affect evidently by δ_e. With the increase of δ_e, the center of backflow under the same q will go downstream. When δ_e=0.4mm, the center of backflow goes farthest. Then, as the further increase of δ_e, the center of backflow will go back some distance. Although, δ_e has relatively great influence on the flow field within the jet pump, it exerts only a little impact on the performance of jet pump. When δ_e=0.2∼0.6mm, the jet pump possess better performance. In most case, it is reasonable to ignore the nozzle exit tip thickness in performance prediction for the purpose of simplicity

[en] Shenzhen city is a high soil radon background district in our country. To evaluate the region public radon radiation exposure levels to the human, RAD-7 was used to supervise indoor radon concentration levels at the selected 44 different public sites. The results of survey show that places the arithmetic mean is 26.7 ± 17.3 Bq/m³, and the geometric average is 22.3 ± 1.9 Bq/m³ for the indoor radon concentration in the district of Futian public; indoor radon concentrations are varied with different building materials, with the highest in high-rise building; compared to historical data, only high-rise building indoor radon concentration is on the rise. The survey data of public indoor radon concentration could have certain reference significance for the evaluation and protection in the city of Shenzhen. (authors)

[en] Objective: To study the MRI findings in a series of intracranial hemangiopericytomas, and to compare these findings with those of intracranial meningiomas. Methods: The MRI appearances and clinical features in 27 cases of intracranial hemangiopericytomas and 236 cases of intracranial meningiomas were retrospectively reviewed. All cases were proved by operation and pathology. The data were evaluated by using χ² test, rank sum test, and Logistic Regression. Results: Sex (χ² = 6.981) , shape of tumor (χ² = 39.949), signal voids of vessel in tumor (χ² = 12.366), necrosis or cystic degeneration in tumor (χ²=37.432), the type of dural attachment ( broad-based or narrow-based ) (χ²=16.956), T₁WI signal intensity (χ²=14.880), T₂WI signal intensity (χ²=37.068), enhanced degree of tumor (χ²=10.081), homogeneous degree of tumor after contrast enhancement (χ²=17.014 ), and duration time were significant different (P < 0.01) between hemangiopericytoma group and meningioma group. In addition, there was a significant difference (P < 0.05) between the two groups with 'dural tail' sign (χ²=5.655), duration time, and age of the first presentation (t =2.502). In Logistic regression analysis, shape of tumor showed significant difference (P < 0.01) between the two groups. T₂WI signal intensity and 'dural tail' sign also showed significant difference (P < 0.05) between the two groups in Logistic regression analysis. Conclusion: Our data indicated that presence of the multilobulated tumor, iso- and hyperintensity on T₂WI, and lack for 'dural tail' sign were the most important characteristics for differentiating intracranial hemangiopericytoma from meningioma. It is helpful to get a correct diagnosis with other MRI and clinical features

[en] Numerical simulation is employed for the HL-2A modification, which includes the optimum design of zero-field in the start-up phase, the limiter equilibrium configuration, the single/double null divertor equilibrium configuration, and the equilibrium configuration evolution from gas breakdown to current plateau. Results show that the new program can satisfy the design requirement. (authors)

[en] Fluorine-doped tin oxide films were deposited on Na-Ca-Si glass substrate at 650 °C by chemical vapor deposition, and then heat treatment was carried out at 200 °C, 400 °C and 600 °C for 4 min in a resistance furnace. The residual stress in SnO₂:F films was systematically measured using the sin²Ψ method based on X-ray diffraction. The incidence angle was adopted as Ψ = 0°, 15°, 20°, 25° and 30°. The results showed that the films were polycrystalline with tetragonal SnO₂ structure, together with a weak peak of SnO phase. All the films exhibited a preferred orientation with the (200) plane. The minimum value of residual stress (− 0.24 ± 0.01 GPa) was obtained when the films were heat-treated at 200 °C. - Highlights: ► SnO phase was present in polycrystalline F-doped SnO₂ film. ► All the films exhibit an (200) preferred orientation. ► The minimum residual stress was obtained when samples are heat-treated at 200 °C. ► Both intrinsic and thermal stress co-exist and affect the films' residual stress.

[en] Error field caused by non-coaxiality among poloidal and toroidal field coils on HL-2M tokamak is calculated with SURFMN and SURFMN_TFCOIL code. According to the coil installation error chosen by international tokamak and the installation experience of HL-2A tokamak, the maximum shift distance of poloidal-and toroidal-field coils on HL-2M tokamak is chosen 3-8 mm, and the maximum tilt angle of that is 0.05-0.1 degree. The probability density and accumulative probability of error field are calculated with the maximum shift distance 3 mm, 5 mm and 8 mm respectively, and the maximum tilt angle 0.05, 0.075 and 0.1 degree respectively. The results show that: (1) the probability density distribution become flat and the range of error field B_3-mode /B_T is enlarged significantly with the increase of maximum shift distance of field coils;(2) the shift of poloidal-and toroidal-field coils influences error field more heavily than tilt does; (3) when the shift of poloidal-and toroidal-field coils reaches 5 mm,especially 8 mm, the error field is more possibly reach 2 x 10^-4. (authors)

[en] Gout is an inflammatory reaction as a result of monosodium urate crystal deposition in joints, periarticular soft tissue, cartilage, and kidney. Although diagnosing gout generally is straight forward when presenting typical clinical symptoms, serum urate level and common imaging modalities, atypical disease may still be a challenge. Dual-energy computed tomography (CT) can be used to differentiate urate crystals from calcium by using specific attenuation characteristics. Dualenergy CT can be used for volumetric quantification through an automated volume assessment software. Given the utility of dual-energy CT in challenging cases and its ability of providing an objective outcomes measure in patients with tophaceous gout, dual-energy CT promises to be a unique and clinically relevant modality in the diagnosis and management of tophaceous gout. (authors)

[en] The equilibrium fitting code (EFIT) is used to design the basic configurations which include the limiter, double null divertor and single null divertor configurations. These configurations with high elongation and large triangularity, meet the main configuration parameters given by the physical target of HL-2M tokamak: the major radius is 1.78 m and the minor radius up to 0.65 m. In consideration of the influence of CS coil current on configurations and the limits of PF coils current, several discharges waveforms of three basic configurations was designed with the plasma current equal to 1.2 MA which is the normal current for the HL-2M discharge schemes. The other discharges waveforms with the plasma current equal to 3 MA are designed also. In addition, the volt-seconds consumption is analyzed by tokamak simulation code (TSC) for the HL-2M discharge evolution process with the plasma current equal to 1.2 MA. (authors)

[en] OILs are measurable radiation parameters which are related to the generic intervention level of the specific action for public protection. OILs can be used to provide recommendations on emergency protective actions through comparison with environmental monitoring data. After Fukushima nuclear accident, emergency preparedness and response of nuclear power plants in China focuses on the issues of multi-unit accident. Based on the methods of calculation and revision of OILs suggested by IAEA, methods of calculation OILs for multi-unit accident were established, and the corresponding decision support system was also designed and implemented. The system provided a complete process for use of OILs including the function of data management, data query, calculation, revision and decision on protective actions, which can be used for both single-reactor and multi-reactor accident. The system has been applied in Qinshan, Ningde, Sanmen, Taishan and Yangjiang NPPs in China. (authors)

[en] In order to elucidate the mechanism of action of lithium on the thyroid gland, we studied the effect of lithium on the ¹²⁵I up-take in thyroid cells in vitro. After culturing FRTL-5 cells 7 days in a medium lacking TSH, the cells were incubated with various concentrations of lithium (0.5∼10 mmol/L) and TSH (50, 100 mU/L) for 24 h. Iodide uptake was initiated by adding 500 μl buffered HBSS containing 0.1 μCi carrier-free Na ¹²⁵I and 10 nmol/L NaI. After incubation, the cells were dissolved and their radioactivities counted. The ¹²⁵I uptake in FRTL-5 cells rose to peak level in 30 minutes. Prolonging the incubation period did not change the iodide uptake. During the peak phase sodium perchloride suppressed the ¹²⁵I uptake more than 90%. The iodide uptake induced by TSH was inhibited at 1 mmol/L lithium (P<0.05). More than 50% inhibition was observed at 2∼10 mmol/L lithium. There was no effect of lithium on the iodide uptake in the basal condition of FRTL-5 cells (lacking TSH). Lithium inhibits iodide uptake in thyroid cells in the presence of TSH