共查询到20条相似文献,搜索用时 62 毫秒
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国家"十二五"工程将在哈尔滨工业大学建造一台空间辐射地面模拟装置(SESRI),该装置能够模拟空间辐照环境,对研究离子辐照材料、生命体等具有重要意义。SESRI主要由双ECR离子源,直线注入器,同步环和3个高能实验终端组成。周长为43.9 m的同步环作为装置的核心部分,能够向3个实验终端输送离子种类多、能量范围广的粒子束。为了保证环内有足够的粒子数,注入系统的设计至关重要,SESRI同步环采用多圈注入方案,并利用ACCSIM程序模拟粒子真实运动情况。结果表明,粒子的注入效率为85.5%,离子数增益可达17.1,可满足设计要求。Space Environment Simulation and Research Infrastructure (SESRI), which is one of the large-scale scientific projects proposed in National Twelfth Five-Year Plan of China, will be constructed in Harbin Institution of Technology. The SESRI project dedicated to space radiation consists of two ECR ion sources, a high intensity ion linac, a synchrotron and 3 research terminals. As the key part of the complex, a 43.9 m synchrotron can provide broadest energy range and variable ion beam for each terminal. To obtain required intensity in the synchrotron, the injection system is significant. A multi-turn injection scheme is adopted in the synchrotron and the injection process is simulated by ACCSIM with multi-particle tracking method. The results show that the injection efficiency and intensity gain factor can reach 85.5% and 17.1 respectively. The multi-turn injection system can meet the design requirement. 相似文献
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为满足ITER相关设计准则,采用有限元分析方法,以ITER装置单个端口气体注入管线为例,对注入管线开展线弹性应力分析并进行了设计优化。分析结果表明原管线柔性未得到有效限制,在较大形变处增设支撑是必要的。优化后的分析结果显示注入管线在限制柔性的同时管线中的应力值满足设计规范的评判标准,没有出现塑性塌陷、局部失效和棘轮效应,而且支撑等部件的支反力减小33%。验证了优化方案的可行性,最终管线结构的可靠性和安全性得到了明显的改进。 相似文献
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提出了一种基于方向性靶标和多约束优化的双目相机标定方法。新型方向性平面靶标能够判断靶标的旋转方向,并对每个标定角点进行编码,以保证双目相机在拍摄到局部靶标的情况下依然能够完成同名点匹配,进而完成双目相机标定。根据方向性靶标建立双目相机标定模型,引入用于描述平面靶标姿态的天顶角和方位角,通过天顶角和方位角筛选出在不同位置上的靶标姿态均具有明显差异的图像作为标定图像,这提高了双目标定结果的稳定性;结合靶标的三维几何信息,建立了多维度约束的双目参数优化模型,提高了双目标定结果的精度。实验结果表明,与传统的张氏标定方法相比,所提出的标定方法能够有效提高所获得的标定结果的稳定性和精度;通过对标准量块进行多次测量,进一步验证了所提方法的有效性。 相似文献
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Improved Computer Program for Magnetron Injection Gun Design 总被引:1,自引:0,他引:1
Yi Sheng Yeh Ming Hsiung Tsao Han Ying Chen Tsun-Hsu Chang 《International Journal of Infrared and Millimeter Waves》2000,21(9):1397-1415
Gyrotron has received extensive attention owing to its high-power capability, especially when the wavelength shrinks below the millimeter-wave range. The electron beam of a gyrotron is typically generated by a magnetron injection gun (MIG). For high cathode current density, the MIG may operate in a region that combines temperature limited and space-charge limited emissions. An improved computer program for electron gun design is appropriate for MIGs that operate between space-charge limited and temperature limited emission. Moreover, the initial input formation of the program resembles that of the EGUN code. Analysis of a Pierce electron gun and MIGs reveals that the stimulated beam current appears consistent with the measured results. However, EGUN simulation results in which the cathode emitters of MIGs are chosen for the temperature limited emission differ from those of our simulation results. This difference is most likely owing to that the initial emitting energy can not be completely described in the EGUN simulation. Finally, the improved computer program is used to design a MIG for a Ka-band, TE01 mode gyro-TWT. 相似文献
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Journal of Applied Spectroscopy - A simple, accurate, novel, safe, and precise method was developed for the estimation of erlotinib hydrochloride in tablet dosage form using a mixture of methanol... 相似文献
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Journal of Applied Spectroscopy - A reproducible, sensitive, and cost-effective spectrofluorimetric method has been developed for quantification of the drug ibrutinib in bulk and in its oral... 相似文献
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《Journal of voice》2019,33(6):948.e23-948.e29
PurposeThe Dysphonia Severity Index (DSI) is an objective multiparameter index of voice quality that measures and describes overall voice quality. Some studies have suggested that the reliability of devices for DSI measurement should be examined. We explored the feasibility of DSI measurements using the Dr. Speech (DRS) device, verified its effectiveness for clinical voice measurements and intradevice reliability, and examined the correlation between the DSI and self-evaluations of voice problems.MethodsSeventy adult participants (including individuals with voice problems and healthy adults) underwent objective and subjective voice assessments. These data were then used to establish a DSIDRS model and test the intradevice (DRS device and Praat software) reliability. The clinical validation of the DSIDRS was conducted by measuring the DSI of six other participants and comparing the observed and predicted perceived voice quality as expressed by the G score (of the GRBAS scale). Moreover, the relationship between the DSI measurements and participants’ self-evaluations of voice problems was investigated by analyzing the correlation between the DSI and the Voice Handicap Index (VHI).ResultsThe DSIDRS discriminated 80% of participants’ voice quality ratings. There were strong correlations between the DSI and variables measured by the DRS device and Praat software. Furthermore, there was no significant correlation between the DSIDRS and VHI.ConclusionThe DRS device can perform DSI measurements. Objective voice measurements and perceptual voice ratings reflected different aspects of vocal function and its effects. These factors should be considered in clinical practice settings. 相似文献