The Compact Pulsed Hadron Source （CPHS） project is a university-based proton accelerator platform （13 MeV,16 kW,50 mA peak current,0.5 ms pulse width at 50 Hz） for multi-disciplinary neutron and proton application...The Compact Pulsed Hadron Source （CPHS） project is a university-based proton accelerator platform （13 MeV,16 kW,50 mA peak current,0.5 ms pulse width at 50 Hz） for multi-disciplinary neutron and proton applications.The CPHS linac consists of a 3 MeV radio-frequency quadrupole （RFQ） linac and a 13 MeV drift tube linac （DTL）.Both the RFQ and DTL share a 325 MHz,2.1 MW klystron source.A single iris-type radio-frequency （RF） coupler is used to feed 537 kW of RF power to the RFQ cavity.Three-dimensional electromagnetic models of the ridge-loaded tapered waveguide （RLWG） and the coupler-cavity system are presented,and the design process and results of the RLWG and iris plate are described in detail.展开更多
AIM: To evaluate the characters, risks and benefits of laparoscopic cholecystectomy (LC) in cirrhotic portal hypertension (CPH) patients.METHODS: Altogether 80 patients with symptomatic gallbladder disease and CPH, in...AIM: To evaluate the characters, risks and benefits of laparoscopic cholecystectomy (LC) in cirrhotic portal hypertension (CPH) patients.METHODS: Altogether 80 patients with symptomatic gallbladder disease and CPH, including 41 Child class A,32 Child class B and 7 Child class C, were randomly divided into open cholecystectomy (OC) group (38 patients) and LC group (42 patients). The cohorts were well-matched for number, age, sex, Child classification and types of disease.Data of the two groups were collected and analyzed.RESULTS: In LC group, LC was successfully performed in 36 cases, and 2 patients were converted to OC for difficulty in managing bleeding under laparoscope and dense adhesion of Calot's triangle. The rate of conversion was 5.3%. The surgical duration was 62.6±15.2 min. The operative blood loss was 75.5±15.5 mL. The time to resume diet was 18.3±6.5 h. Seven postoperative complications occurred in five patients (13.2%). All patients were dismissed after an average of 4.6±2.4 d. In OC group, the operation time was 60.5±17.5 min. The operative blood loss was 112.5±23.5 mL. The time to resume diet was 44.2±10.5 h.Fifteen postoperative complications occurred in 12patients (30.0%). All patients were dismissed after an average of 7.5±3.5 d. There was no significant difference in operation time between OC and LC group. But LC offered several advantages over OC, including fewer blood loss and lower postoperative complication rate, shorter time to resume diet and shorter length of hospitalization in patients with CPH.CONCLUSION: Though LC for patients with CPH is difficult, it is feasible, relatively safe, and superior to OC.It is important to know the technical characters of the operation, and pay more attention to the meticulous perioperative managements.展开更多
The essay makes comprehensive literature review and analysis on various scientific experiments and research about the role of age in second language learning. Moreover, the introduction and analysis of"Critical P...The essay makes comprehensive literature review and analysis on various scientific experiments and research about the role of age in second language learning. Moreover, the introduction and analysis of"Critical Period Hypothesis"and its relevant research in second language acquisition has been presented in order to put forward some scientific implications for second lan guage learning and instruciton in the context of China.展开更多
文摘The Compact Pulsed Hadron Source （CPHS） project is a university-based proton accelerator platform （13 MeV,16 kW,50 mA peak current,0.5 ms pulse width at 50 Hz） for multi-disciplinary neutron and proton applications.The CPHS linac consists of a 3 MeV radio-frequency quadrupole （RFQ） linac and a 13 MeV drift tube linac （DTL）.Both the RFQ and DTL share a 325 MHz,2.1 MW klystron source.A single iris-type radio-frequency （RF） coupler is used to feed 537 kW of RF power to the RFQ cavity.Three-dimensional electromagnetic models of the ridge-loaded tapered waveguide （RLWG） and the coupler-cavity system are presented,and the design process and results of the RLWG and iris plate are described in detail.
文摘AIM: To evaluate the characters, risks and benefits of laparoscopic cholecystectomy (LC) in cirrhotic portal hypertension (CPH) patients.METHODS: Altogether 80 patients with symptomatic gallbladder disease and CPH, including 41 Child class A,32 Child class B and 7 Child class C, were randomly divided into open cholecystectomy (OC) group (38 patients) and LC group (42 patients). The cohorts were well-matched for number, age, sex, Child classification and types of disease.Data of the two groups were collected and analyzed.RESULTS: In LC group, LC was successfully performed in 36 cases, and 2 patients were converted to OC for difficulty in managing bleeding under laparoscope and dense adhesion of Calot's triangle. The rate of conversion was 5.3%. The surgical duration was 62.6±15.2 min. The operative blood loss was 75.5±15.5 mL. The time to resume diet was 18.3±6.5 h. Seven postoperative complications occurred in five patients (13.2%). All patients were dismissed after an average of 4.6±2.4 d. In OC group, the operation time was 60.5±17.5 min. The operative blood loss was 112.5±23.5 mL. The time to resume diet was 44.2±10.5 h.Fifteen postoperative complications occurred in 12patients (30.0%). All patients were dismissed after an average of 7.5±3.5 d. There was no significant difference in operation time between OC and LC group. But LC offered several advantages over OC, including fewer blood loss and lower postoperative complication rate, shorter time to resume diet and shorter length of hospitalization in patients with CPH.CONCLUSION: Though LC for patients with CPH is difficult, it is feasible, relatively safe, and superior to OC.It is important to know the technical characters of the operation, and pay more attention to the meticulous perioperative managements.
文摘The essay makes comprehensive literature review and analysis on various scientific experiments and research about the role of age in second language learning. Moreover, the introduction and analysis of"Critical Period Hypothesis"and its relevant research in second language acquisition has been presented in order to put forward some scientific implications for second lan guage learning and instruciton in the context of China.
