[en] The paper describes the process and steps of hydraulic test for VVER-1000 nuclear power plant. Combined with design documents, standards and specifications and compared with first-stage project of Tianwan and typical plants in China, it puts forward the test acceptance criteria, test pressure, temperature requirements and control methods, and summarizes the preparation and precautions for the primary loop hydraulic test for Tianwan Unit 3, which leads a guiding role for the hydraulic test procedure and test execution, and offers reference for the follow-up hydraulic test and commissioning for plants of the same kind. (author)

[en] An attempt is made to investigate the ability of the revised K-FIX code to the solution to natural convection. The new experimental data of the benchmark problem of the IAEA coordinated research program (CRP-3) on heat transport and after heat removal for GCRs under accident conditions provided by JAERI are used to calculate nitrogen natural convection in the pressurized vessel and air natural convection in the reactor cavity by using this revised code. Based on analysis, a refined mesh is used to solve the differential equations so as to get more detailed and more accurate result. The obtained velocity profiles are consistent with the result of TRIO-EF code and the result of Bechtel laboratory. It can be drawn that the revised K-FIX code can be used to solve this kind of problems

[en] A Comment on the Letter by Natalia Berseneva, Arkady V. Krasheninnikov, and Risto M. Nieminen, Phys. Rev. Lett. 107, 035501 (2011). The authors of the Letter offer a Reply.

[en] In this study, We adopted the theory of the polymerism to synthesize the scintillator, and we composed the scintillating material (2, 5-diphenyloxazole (PPO) and 1, 4-bis-(2-(5-phenyloxazolyl))-benzene (POPOP)) to the plastic (PMMA) successfully by the polymerization. We found that the scintillating material (PPO and POPOP) spread well into the plastic and the scintillator could be well seasoned with many different environmental condition through the spectroanalysis and the mechanical testing. We also found that the scintillator was well responded to the γ-ray testing which we did. According to the increase of the content for the PPO, the radiant efficiency of the γ-ray testing was increase too. (authors)

[en] On the basis of density functional theory calculations, we have systematically investigated the electronic properties of armchair-edge graphene nanoribbons (GNRs) doped with boron (B) and nitrogen (N) atoms. B (N) atoms could effectively introduce holes (electrons) to GNRs and the system exhibits p- (n-) type semiconducting behavior after B (N) doping. According to the electronic structure calculations, Z-shape GNR-based field effect transistors (FETs) is constructed by selective doping with B or N atoms. Using first-principles quantum transport calculations, we demonstrate that the B-doped p-type GNR-FETs can exhibit high levels of performance, with high ON/OFF ratios and low subthreshold swing. Furthermore, the performance parameters of GNR-FETs could be controlled by the p-type semiconducting channel length.

[en] Objective: To investigate the bronchial artery imaging features of the patients with primary lung cancer by 64-slice CT angiography (CTA) and its clinical value. Methods: 37 cases of primary lung cancer by pathology underwent enhanced 64-slice CT scan. Three dimensional images of the bronchial arteries were processed at the workstation. Spatial anatomical characters of the bronchial arteries were observed using VR and MPR or MIP. Results: 40 bronchial arteries of 36 cases in all the 37 cases could be presented clearly. The detection rate was 97.3%. 3 bronchial arteries (7.5%) are from the aortic arch; 33 bronchial arteries (82.5%) are from the descending aorta; 4 bronchial arteries (10%) are from the intercostals artery. Of all, the caliber of the bronchial arteries and the total axial areas on the side of the lung cancer were significantly larger than those of the other side. Conclusion: 64-slice CT angiography (CTA) is a safe, non- invasive, simple, and effective method in showing the bronchial artery, which can reveal the origin, number, shape, pathway of the bronchial artery in the primary lung cancer. (authors)

[en] Objective: To evaluate the diagnostic value of CT in solid pseudo-papillary tumor of pancreas(SPTP). Methods: CT features of six patients with pathologically proved SPTP were retrospectively analyzed. Results: In all 6 cases, SPTP located in head of pancreas in 2 cases, tail in 4 cases. All tumors were solid-cystic. After contrast administration, there were enhancement in solid area while no enhancement in cystic area. The 'floating cloud' sign was characteristic. The tumor was mainly located in the pancreas with complete capsule; no common bile duct dilatation was accompanied. Conclusion: The CT characteristic findings might be of great value in differential diagnosis of SPTP. (authors)

[en] High-activity, visible-light-driven photocatalysts were prepared by forming N-doped TiO₂ on multi-walled carbon nanotubes (MWCNTs). The use of MWCNTs as the support in a N-doped TiO₂ system favored electron trapping, because the recombination process could be retarded, thus promoting photocatalytic activity. The prepared photocatalysts were systematically characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunaure-Emmett-Teller (BET) spectroscopy, and UV-Vis diffuse reflectance spectroscopy (UV-Vis/DRS). The results indicated that the N-doped TiO₂ coated on MWCNTs improved the surface area and slightly modified the optical properties of the composite. The activities of the photocatalysts were probed by photodegradation of methanol in the presence of visible light irradiation. The experimental results revealed that the strong interphase linkage between the MWCNTs and the N-doped TiO₂ played a significant role in improving photocatalytic activity. However, the mechanical process for MWCNT-TiO_2-xN_x mixtures showed lower activity than just pure N-doped TiO₂. In this study, N-doped TiO₂ precursors coated with pretreated MWCNTs during a sol-gel process could effectively form a MWCNT-TiO_2-xN_x composite. The composite showed excellent activity and effectively enhanced the efficiency of N-doped TiO₂ under the visible light region.

[en] Objective: To explore a CT-guided technology of placing a needle percutaneously under zygomatic arch into the foramen rotundum, and to provide a new path to make radiofrequency thermocoagulation of super-choice trigeminal neuralgia branch II. Methods: With an adult skull specimen, the best angle was chosen from zygomatic arch into foramen rotundum for placement of a 22 gauge needle. And the skull specimen was scanned by CT to establish a standard image of foramen rotundum. The foramen rotundum of trigeminal neuralgia branch II was scanned according to the standard image, and a needle was placed from zygomatic arch into foramen rotundum guided by CT in 21 patients. Radiofrequency thermocoagulation was made in trigeminal nerve branch II through foramen rotundum. Hypoesthesia range and curative effect were observed. And satisfactory curative effect was achieved by the complete obliteration of pain after radiofrequency thermocoagulation. Results: With the needle and adult skull specimen, the standard image of foramen rotundum could be established. And it could be used as a guide for percutaneous under-zygomatic arch approach into foramen rotundum. By this approach, Radiofrequency thermocoagulation was performed successfully in 21 patients with trigeminal neuralgia branch II. Follow-up period ranged from 1 week to 12 months (7.0 ± 2.4) months, there was satisfactory curative effect and no recurrence of pain. Conclusion: Percutaneous radiofrequency thermocoagulation from zygomatic arch into foramen rotundum offers a new approach to treat trigeminal neuralgia branch II under CT guidanc. (authors)

[en] Objective: To determine the characteristic features of solitary necrotic nodule (SNN) of the liver on precontrast and dynamic contrast enhanced magnetic resonance (MR) imaging. Methods: We retrospectively reviewed 15 patients with histopathologically proved SNN. All of the images were evaluated for lesion features including the number, shape, size, location, border, signal intensity and pattern of enhancement. Results: Sixteen lesions were found in 15 patients. Nonenhanced T₁- and T₂ weighted images depicted 15 lesions in 14 patients and 14 lesions in 13 patients respectively. Maximum diameter of 14 lesions was less than 3 cm. On unenhanced T₁-weighted images, 5 lesions were hypointense, 9 lesions were slightly hypointense, and 1 was isointense with hypointense capsule and central punctate hypointense foci. Among 14 lesions demonstrated on T₂-weighted images, 5 were hyperintense, 4 were slightly hyperintense, 3 were slightly hypointense, and 2 were hypointense. Punctate or linear high signal intensities were found in 2 lesions. All lesions were not enhanced after contrast injection. On portal venous and delayed phase, all lesions appeared significantly hypointense with well-defined border. The shape was irregular in 12 lesions and was round or oval in 4 lesions. No enhancement was found in the lesion except thin delayed enhancement in capsules of 3 lesions after contrast agent administration. Conclusion: Characteristic MRI features of SNN are helpful for distinguishing SNN from other hepatic lesions. (authors)