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大肠杆菌FC40系统静止期突变中的F因子转移 被引量:1
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作者 张汉波 沙涛 +4 位作者 程立忠 丁骅孙 施雯 于春蓓 张会荣 《遗传》 CAS CSCD 北大核心 2003年第4期428-432,共5页
本研究采用大肠杆菌GM133 rif^r细胞和营养收集细胞HB214 sir^r进行适应性突变实验。在混合30min和2d后添加链霉素杀死GM133基因型细胞,继续培养5d后,在选择平板上出现了一定数量的lac^+str^r基因型回复突变菌落。根据这些突变菌落的数... 本研究采用大肠杆菌GM133 rif^r细胞和营养收集细胞HB214 sir^r进行适应性突变实验。在混合30min和2d后添加链霉素杀死GM133基因型细胞,继续培养5d后,在选择平板上出现了一定数量的lac^+str^r基因型回复突变菌落。根据这些突变菌落的数量,估计在lac^+突变产生之前,GM133和HB214细胞之间的接合频率分别为0.07%和7.47%。在培养了7d的选择平板上添加含链霉素的M9选择培养基,2d后也观察到大量发生lac^+突变但没有形成肉眼可见菌落的营养收集细胞。此外,在lac^+突变发生后,也有F因子从GM133细胞转移进入HB214细胞。这些事实表明,在FC40系统的适应性突变实验中发生了真正的F因子转移。 展开更多
关键词 大肠杆菌fc40系统 适应性突变 F因子转移 静止期
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CMOS direct conversion X-ray detector coupled with fluorinated liquid 被引量:1
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作者 Shi-Hua Liu Chao-Song Gao +5 位作者 Xin Zhang Xiang-Ming Sun Meng Wu Zhi-Hui Han Tong Wan Yong-Shuai Ge 《Nuclear Science and Techniques》 2025年第1期59-68,共10页
X-ray detectors show potential applications in medical imaging,materials science,and nuclear energy.To achieve high detection efficiency and spatial resolution,many conventional semiconductor materials,such as amorpho... X-ray detectors show potential applications in medical imaging,materials science,and nuclear energy.To achieve high detection efficiency and spatial resolution,many conventional semiconductor materials,such as amorphous selenium,cadmium telluride zinc,and perovskites,have been utilized in direct conversion X-ray detectors.However,these semiconductor materials are susceptible to temperature-induced performance degradation,crystallization,delamination,uneven lattice growth,radiation damage,and high dark current.This study explores a new approach by coupling an FC40 electronic fluorinated liquid with a specialized high-resolution and high-readout-speed complementary metal-oxide-semiconductor(CMOS)pixel array,specifically the Topmetal II−chip,to fabricate a direct conversion X-ray detector.The fluorinated liquid FC40(molecular formula:C_(21)F_(48)N_(2))is an electronic medium that is minimally affected by temperature and displays no issues with uniform conductivity.It exhibits a low dark current and minimal radiation damage and enables customizable thickness in X-ray absorption.This addresses the limitations inherent in conventional semiconductor-based detectors.In this study,simple X-ray detector imaging tests were conducted,demonstrating the excellent coupling capability between FC40 electronic fluorinated liquid and CMOS chips by the X-ray detector.A spatial resolution of 4.0 lp/mm was measured using a striped line par card,and a relatively clear image of a cockroach was displayed in the digital radiography imaging results.Preliminary test results indicated the feasibility of fabricating an X-ray detector by combining FC40 electronic fluorinated liquid and CMOS chips.Owing to the absence of issues related to chip-material coupling,a high spatial resolution could be achieved by reducing the chip pixel size.This method presents a new avenue for studies on novel liquid-based direct conversion X-ray detectors. 展开更多
关键词 fc40 electronic fluorinated liquid CMOS pixel chip X-ray detector Spatial resolution
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利用并行口监测系统状态
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作者 徐晓东 刘江虹 《内蒙古大学学报(自然科学版)》 CAS CSCD 北大核心 2003年第4期450-453,共4页
介绍了并行口SPP模式的特点和显示模块FC40X2EA的主要功能,提供一种利用计算机并行口的SPP模式与显示模块FC40X2EA连接,用软件代替硬件来完成对系统状态进行监测的方法;给出控制显示模块FC40X2EA的过程和两个实用子程序.
关键词 并行口 SPP模式 fc40X2EA显示模块 子程序
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