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Two externally biased electrodes were inserted into the plasma on the KT-5C tokamak to test the effects on modifying the radial electric field Er, other than single biasing. Using various combinations of biasing voltage,the influences of double biasing are compared with the single biasing. It turns out that the effect of dual-biasing is also effective as a single one, but the outer electrode seems to be shielded by the inner one and show less influence. The results clearly show that the radial electric field Er changed by external biasing is intrinsically an effect localized at the edge of the plasma, which is caused by the electrode induced radial current; and dualelectrode biasing using the method similar to the single biasing seems not to be able to increase more distinctly the peaking effect on Er than the single biasing. 相似文献
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在HL-2A装置上完成了一套32通道束发射诊断系统(BES),可对径向r=12~44cm, 极向-7.5~+7.5cm二维空间范围内的长波长()电子密度扰动信息进行测量,其时间分辨率达到0.5ms,空间分辨率1~2cm。系统由内置于真空室的非对称镜头组、传输光纤、高性能探测器模块以及辅助的冷却和真空设备构成。系统的噪声在低频时(f<100kHz)主要由散粒噪声贡献,在较高频率时由散粒噪声和e噪声共同决定。在典型的HL-2A装置放电模式中,对于200kHz以下的扰动,该系统的信噪比(SNR)均大于3。 相似文献
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In tokamak plasma fueling, supersonic molecule beam injection(SMBI) with a higher fueling efficiency and a deeper penetration depth than the traditional gas puffing method has been developed and widely applied to many tokamak devices.It is crucial to study the transport dynamics of SMBI to improve its fueling efficiency, especially in the high confinement regime. A new one-dimensional(1D) code of TPSMBI has also been developed recently based on a six-field SMBI model in cylindrical coordinate. It couples plasma density and heat radial transport equations together with neutral density transport equations for both molecules and atoms and momentum radial transport equations for molecules. The dominant particle collisional interactions between plasmas and neutrals, such as molecule dissociation, atom ionization and charge-exchange effects, are included in the model. The code is verified to be correct with analytical solutions and also benchmarked well with the trans-neut module of BOUT++ code. Time-dependent radial transport dynamics and mean profile evolution are studied during SMBI with the TPSMBI code in both slab and cylindrical coordinates. Along the SMBI path, plasma density increases due to particle fuelling, while plasma temperature decreases due to heat cooling. Being different from slab coordinate, the curvature effect leads to larger front densities of molecule and atom during SMBI in cylindrical coordinate simulation. 相似文献
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We study the molecular penetration depth variation with the SMBI fluxes.The molecular transport process and the penetration depth during SMBI with various injection velocities and densities are simulated and compared.It is found that the penetration depth of molecules strongly depends on the radial convective transport of SMBI and it increases with the increase of the injection velocity.The penetration depth does not vary much once the SMBI injection density is larger than a critical value due to the dramatic increase of the dissociation rate on the fueling path.An effective way to improve the SMBI penetration depth has been predicted,which is SMBI with a large radial injection velocity and a lower molecule injection density than the critical density. 相似文献
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仅在一阶矩有限的条件下获得了非负NOD随机变量序列正则和的逆矩的渐近逼近,特别得到了部分和的逆矩的渐近逼近.本文的结论推广了已有的结果. 相似文献
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乙烯装置裂解炉管焦炭燃烧特性的研究 总被引:4,自引:1,他引:3
齐鲁石化公司乙烯厂是我国最先引进计算机控制下蒸汽 空气在线烧焦技术的乙烯厂 ,在线烧焦使其过程自动化程度大大提高 ,裂解炉没有升降温过程 ,延长了裂解炉管的使用年限[1~ 5] 。但裂解气盘管管径较小 ,易于堵塞 ,烧焦时间稍短 ,管壁上的焦炭就燃烧不完全 ,目前在线烧焦时间还需 70h~ 80h。为了进一步缩短烧焦时间 ,节约能源 ,提高炉子运行周期 ,必须对乙烯装置裂解炉管焦炭的微观结构及燃烧过程进行深入研究 ,以提出进一步加快烧焦速度的办法 ,满足工业生产的需要。本研究采用国内某乙烯厂裂解炉管焦炭为实验原料 ,研究了焦炭的微观… 相似文献
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光动力治疗(PDT)已成为治疗癌症的重要方法之一。传统光敏剂由于存在选择性差、易光漂白等问题,极大地限制了其在临床上的应用。而具有聚集诱导发光特性的荧光分子(AIEgens),在光照条件下能产生活性氧,并能够将肿瘤细胞杀死,具有治疗癌症的功效。此外,AIEgens还具有易制备、荧光特性优异、生物相容性好以及被动靶向效应(EPR效应)等优点,已被广泛应用于光动力治疗领域,并取得了巨大的发展,具有潜在的医学应用价值。该文主要概括并讨论了近5年来AIEgens在光动力治疗中的研究进展,并进行了展望。 相似文献
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