HIRFL-CSR实验环高频同轴谐振腔设计原理

介绍了同步加速器高频铁氧体加载腔体的设计原理和设计计算过程。详细说明了腔体加载铁氧体材料的作用和意义,并对传统的传输线理论计算结果、CST(Computer Simulation Technol-ogy)软件模拟计算结果和实际腔体测量结果进行了比较

大功率高精度脉冲电源

本实用新型公开一种大功率高精度脉冲电源，是将主电路的结构和ＩＧＢＴ线性控制方式结合起，将大电流耐高压的开关功率器件应用在线性工作区。这种结构可以实现大电流高电压的脉冲工作模式，可以实现高速大中流脉冲输出，可以实现脉冲输出波形的调整。本实用新型有良好的线性跟踪特性，也可用于高精度宽范围电流输出。其具有控制简单，不容易振荡、电磁兼容性好、电源动态响应速度快，工作可靠性高等优点

Design of RF generator at cooling storage experimental ring

对兰州重离子加速器冷却储存环实验环(CSRe)的高频系统功率源的设计作了详细的工程计算,工作频率范围为0.5～2.0MHz,工作于基波及二次谐波模式,发射机不仅能工作于点频连续波模式,而且还可以工作在扫频调制模式,输出最大功率达到70kW。满足最高加速或减速电压10kV的设计要求,能够用于捕获放射性次级束并将束流的能量从400MeV/u减速到30MeV/u。<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">RF system of HIRFL-CSRe(cooling storage experimental ring) was designed by ourselves and manufactured domestically, which operates in the frequency range of 0. 5~2. 0 MHz at first and second harmonic modes. Based on detailed engineering calculation, the design of RF generator was completed. It will work not only in CW mode but also in the mode of ramping pulse modulation, and the maximum power is up to 70 kW. It satisfies the requirement of 10 kV maximum deceleration voltage to capture the irradiative beam and decelerate the beam from 400 MeV/u to 30 MeV/u.</span

Association between Serological Status and Fluctuation Modes of EBNA1/IgA and Risk of Nasopharyngeal Cancer

分析EB病毒核抗原1-IgA抗体(EBNA1-IgA)的不同状态及变化趋势,并探讨人群的鼻咽癌发病风险。检测中山市小榄镇2009~2010年入组; 的16 695位30~59岁参加鼻咽癌筛查人群血清,按首次筛查和随访中EBNA1/; IgA抗体状态将筛查人群进行分组,对照组为未参加筛查的两个镇区同年龄组人群,利用中山市肿瘤登记系统、死因登记系统随访至2014年12月31日,分; 析各组人群的鼻咽癌发病风险。与对照组相比,基线抗体阴性人群的发病风险比为0.46(95%CI; 0.25~0.86),基线抗体阳性人群的发病风险比为31.1(95%CI; 21.0~46.1);复查人群中上升组、持续阳性组的发病风险比分别为82.4(95%CI 36.1~188.2),26.4(95%CI; 12.3~52.5),而下降组和波动组中未见病例。EBNA1/IgA基线阳性人群在5年中有很高的发病风险,复查人群中上升组和持续阳性组也有很高的; 发病风险,下降组和波动组发病风险较低。We wished to analyze the risk of nasopharyngeal cancer(NPC)in a; population with different status and fluctuation modes of Epstein-Barr; nuclear antigen 1(EBNA1)/immunoglobulin A(IgA)antibody. Serology; detection was conducted in 16,695 participants screened for NPC(30~59; years)enrolled from 2009 to 2010 in Xiaolan Town,Zhonghan; City,China.Participants were divided into groups according to EBNA1/IgA; antibody status at baseline and follow-up.Subjects who did not undergo; screening in two neighboring towns of Xiaolan were designated the; control group.All study participants were followed up to 31December 2014; with linkage to a cancer registry.A population registry in Zhongshan; City was used to analyze NPC risk in different groups.Compared with the; control group,the relative risk(RR)of NPC in participants who were; sero-negative and sero-positive at baseline was 0.46(95%CI 0.25~0.86)and; 31.1(21.0~46.1),respectively.The RR of NPC in participants of the; ascending group and persist-positive group who underwent retesting was; 82.4(95% CI 36.1~188.2)and 26.4(12.3~52.5),respectively. No NPC cases; were observed in the descending group or fluctuating group.Individuals; in the ascending group,persist-positive group and those who were; EBNA1/IgA antibody-positive at baseline had a higher risk of NPC.A lower; risk of NPC in the descending group and fluctuating group was observed; compared with that in the control group.国家科技支撑计划; 中央补助地方卫生专项农村癌症早诊早治项

实用化商品玉米籽粒的近红外光谱品种判别方法研究

近年来利用近红外光谱进行农作物品种判别成为农产品检测的一个新兴方向. 该文提出一种基于近红外光谱的新的实用化商品玉米品种判别系统,此系统既能对系统学习过的品种做出准确判别也能对未学习过的品种做出准确拒识. 首先采用一阶导数法对原始光谱进行预处理,光谱数据经主成分分析后,根据仿生模式识别理论建立判别模型. 在建立模型时文章使用了基于二维单形的Ψ-3神经元作为覆盖单元,并提出了包含指数的概念以辅助判定样品的唯一归属. 测试结果表明,该系统对参与建模的品种有较强的判别能力,即使建模品种达到34个时系统平均正确判别率仍达到91.8%. 同时对于未参与建模的品种也有较强的拒识能力,平均正确拒识率达到95%以