[en] The goal of the Q-weak experiment is to make a measurement of the proton's weak charge Q_W^p = 1 - 4 sin²(θ_W) to an accuracy of ∼ 4%. This would represent a ∼ 0.3% determination of the weak mixing angle sin²(θ_W) at low energy. The measurement may be used for a precision test of the Standard Model (SM) prediction on the running of sin²(θ_W) with energy scale. The Q-weak experiment operates at Thomas Jefferson National Accelerator Facility (Jefferson Lab). The experiment determines Q_W^p by measuring the parity violating asymmetry in elastic electron-proton scattering at low momentum transfer Q² = 0.026 (GeV/c)² and forward angles (?8 degrees). The anticipated size of the asymmetry, based on the SM, is about 230 parts per billion (ppb). With the proposed accuracy, the experiment may probe new physics beyond Standard Model at the TeV scale. This thesis focuses on my contributions to the experiment, including track reconstruction for momentum transfer determination of the scattering process, and the focal plane scanner, a detector I designed and built to measure the flux profile of scattered electrons on the focal plane of the Q-weak spectrometer to assist in the extrapolation of low beam current tracking results to high beam current. Preliminary results from the commissioning and the first run period of the Q-weak experiment are reported and discussed.

[en] An active carbon absorber is mainly used for radioactive iodine absorption and gas purification in an nuclear power plant. According to technical requirement of the Type III absorber developed at Shanghai Nuclear Engineering Research and Design Institute, finite element analysis (FEA) was used for its mechanics analysis. Static analysis under dead weight, design pressure and operating pressure, modal analysis, and seismic analysis were performed. The structure integrity of Type III active carbon iodine absorber was satisfied under different service conditions. The structure weakness was clarified under static and seismic loads,and the structure design was improved based on the FEA results. (authors)

[en] In this paper, the unsteady 3-D turbulent flow fields in an end-suction centrifugal pump with a vaneless volute are studied numerically at three different rotation speeds. The unshrouded impeller of the pump, as a reduced diameter version of the original full-size impeller, has five backswept blades and five pump-out blades. The results show that the flow rate and pressure vary with the rotational speed according to the similarity law, and the normalized internal flow fields at all speeds are very similar. Due to the reduced impeller diameter, the pump efficiency is relatively low. Flows discharged from the front and back blade passages interfere with each other and swirling motion exists in the volute. The pressure fluctuations on the casing wall near the impeller outlet are extracted, and their spectra show that the component at the blade passing frequency was prominent. This study sheds some light on the characteristics of the internal unsteady flow of a centrifugal pump at different rotational speeds, and forms a basis for future study of flow induced pump vibration and noise.

[en] Objective: To construct a voxel mouse model combining with Monte Carlo method used for radiation dose calculation. Methods: A set of slice images obtained from a nude male mouse (28 g) was utilized, all slice images were registered, some organs or tissues were identified, segmented and filled with specific color, and finally the physical property was defined by MCNP application. Results A mouse model with a voxel size of 0.2 mm x 0.2 mm x 0.2 mm, consisting of 14 organs or tissues, was constructed, which could satisfy the requirement of precision for radiation dose distribution calculation and moderate computing time. Conclusion: The voxel mouse model can be used to calculate the quantity of ionization radiation dosimetry in related areas including radiological medicine, nuclear medicine and space radiation medicine. (authors)

[en] Objective: To evaluate the therapeutic effect and safety of neurolytic celiac plexus block (Ncb) using CT guidance through anterior abdominal approach. Methods: The clinical data of 24 patients who were given NCPB because of the suffering of upper abdominal and back pain caused by pancreatic carcinoma and other cancer in advanced stage were retrospectively analyzed. The therapeutic effect was evaluated with complete pain relief and partial pain relief. Results: The effective rate and complete pain relief rate in short period (< 2 weeks) were 91.7% and 45.8% respectively. The effective rate and complete pain relief rate in long period (> 3 months) were 71.4% and 14.3% respectively. No severe complications occurred. Conclusion: NCPB guided by CT through anterior abdominal approach is an effective, safe and simple method to control the upper abdominal and back pain caused by cancer

[en] Objective: To discuss the clinical efficiency of transcatheter arterial chemoperfusion or chemoembolization (TACP/TACE) for treatment of liver metastasis from malignant insulinoma. Methods: 9 cases of liver metastasis from malignant insulinoma were performed with TACP protocol of 5-fluorouracil, epirubicin, mitomycin C and interleukin-2, including 2 patients also received TACE with total 2-8 courses of treatment. Results: All patients finished the interventional therapy uneventfully with no serious complication. After treatment, clinical symptoms disappeared or improved significantly, with obvious response in 2 cases and partial response in 7 cases. Efficacy in imaging revealed obvious response in 1 case, partial response in 7 and no response in 1 case. Conclusion: TACP/TACE for treatment of liver metastasis from malignant insulinoma is safe and effective. (authors)

[en] Head and neck osteosarcoma is a rare tumor. Its clinical features and recurrence pattern are different from those of osteosarcoma in other parts. Osteosarcoma of the head and neck occurs late with a high local recurrence rate and a low distant metastasis rate. Local recurrence is the main cause of death. Surgery is the main treatment. Postoperative radiotherapy is recommended for patients with positive surgical margin, proximal incisional margin and uncertain surgical margin. The role of chemotherapy remains controversial. Effective molecular targeted therapeutics need to be further explored for recurrent, metastatic and unresectable osteosarcoma, . (authors)

[en] Radionuclide analysis of 48 groups of aerosol samples collected in four cities of Hubei Province from December 2017 to November 2018 was carried out by wide energy low background HPGe BE6530, the correlation between the analysis results and the concentration of PM_2.5 or PM₁₀ or SO₂ or NO₂ was studied by SPSS. The monitoring results showed that the annual average values of ⁷Be, ²¹⁰Pb and ⁴⁰K were 4.793 mBq/m³, 1.481 mBq/m³, 56.2 mBq/m³, and 87.5% of ²³²Th activity concentration were lower than the detection limit, with a maximum value of 21.1 mBq/m³; 16.7% of ²²⁶Ra activity concentration were lower than the detection limit, with a maximum value of 19.8 mBq/m³; ²³⁸U activity concentrations were all lower than the detection limit. It was found that ²¹⁰Pb activity was significantly correlated with PM_2.5 and NO₂. (authors)

[en] Objective: To evaluate the clinical value of percutaneous cholecystostomy by using CT guidance for the treatment of acute cholecystitis in elderly, critically ill patients and to discuss relevant complications. Methods: Sixteen elderly, critically ill patients who suffered from acute cholecystitis with high surgical risk, underwent percutaneous cholecystostomy by using CT guidance. The bile was drained with the 7-8.5 F pigtail catheter. The change of clinical symptoms, signs, and WBC counting was observed. Results: All procedures were successfully performed. There was resolution of clinical symptoms and signs within 12-48 hours in 15 of 16 patients. In 5 acalculous patients, the catheter was removed with no sequelae of cholecystitis in 21-28 days. 10 calculous patients received cholecystectomy in 30-60 days. No severe complications occured. Conclusions: Percutaneous cholecystostomy by using CT guidance is an easy, safe, and effective cholecystostomy method. The percutaneous cholecystostomy by using CT guidance plays an important role in the treatment of elderly, critically ill patients with acute cholecystitis

[en] Objective: To evaluate the safety and efficacy of selective segmental sclerotherapy (SSS) of the liver by transportal absolute ethanol injection with an animal experimental study, and to discuss several technical points involved in this method. Methods: Thirty dogs received SSS of the liver by transportal absolute ethanol injection with the injection dose of 0.2-1.0 ml/kg, repeated examinations of blood ethanol level, WBC, and liver functions were done, and CT and pathological examinations of the liver were performed. Results: All dogs treated with SSS survived during the study. The maximum elevation of blood ethanol values occurred in group F. Its average value was (1.603 ± 0.083) mg/ml, which was much lower than that of death level. Transient elevations of blood WBC and ALT were seen. The average values of WBC and ALT were (46.36 ± 7.28) x 10⁹ and (827.36 ± 147.25) U/L, respectively. CT and pathological examinations proved that the dogs given SSS by transportal absolute ethanol injection with the injection dose of 0.3-1.0 ml/kg had a complete wedge-shaped necrosis in the liver. Conclusion: Selective segmental sclerotherapy of the liver by transportal ethanol injection was quite safe and effective if the proper dose of ethanol was injected. SSS may be useful in the treatment of HCC