聚变等离子体中高能量粒子驱动的鱼骨模不稳定性研究

在考虑高能量粒子密度的空间分布及箍缩角分布的条件下,建立了研究鱼骨模的色散关系,并作了数值研究。结果表明：当高能量粒子的密度高于某个阈值时,鱼骨模会在高能量粒子密度梯度最大处被激发,其频率与高能量粒子的环向进动频率一致。在高β_h 区间,高能量勉强通行粒子将驱动鱼骨模进入第二稳定区。高能量捕获粒子能激发非共振鱼骨模,与勉强通行粒子激发的鱼骨模类似,在高β_h 区存在第二稳定区。     

Sustained high βN plasmas on EAST tokamak

Sustained high normalized beta (${\beta }_N～1.9$) plasmas with an ITER-like tungsten divertor have been achieved on EAST tokamak recently. The high power NBI heating system of 4.8 MW and the 4.6 GHz lower hybrid wave of 1 MW were developed and applied to produce edge and internal transport barriers in high ${\beta }_N$ discharges. The central flat q profile with $q(\rho )～1$ at $\rho <0.3$ region and edge safety factor $q_{95}=4.7$ is identified by the multi-channel far-infrared laser polarimeter and the EFIT code. The fraction of non-inductive current is about 40%. The relation between fishbone activity and ITB formation is observed and discussed.     

低杂波电流驱动中的雪崩逃逸增强及鱼骨不稳定性

等离子体中存在的一定数量的高能逃逸电子（E≥1MeV)通过大角度库仑散射从等离子体中碰撞出二次电子，二次电子被低杂波有效地加速成为逃逸电子，这些逃逸电子又被正反馈回等离子体，形成雪崩现象。在此过程中，一部分获得较大横向动量的二次电子或由低杂波驱动的高能电子可能被香蕉轨道捕获，这些被捕获在磁岛中的电子与某种模式的磁场扰动共振时，就出现鱼骨不稳定现象。     

A risk-based statistical investigation of the quantification of polymorphic purity of a pharmaceutical candidate by solid-state F NMR

The DMAIC (Define, Measure, Analyse, Improve and Control) framework and associated statistical tools have been applied to both identify and reduce variability observed in a quantitative ¹⁹F solid-state NMR (SSNMR) analytical method. The method had been developed to quantify levels of an additional polymorph (Form 3) in batches of an active pharmaceutical ingredient (API), where Form 1 is the predominant polymorph. In order to validate analyses of the polymorphic form, a single batch of API was used as a standard each time the method was used. The level of Form 3 in this standard was observed to gradually increase over time, the effect not being immediately apparent due to method variability. In order to determine the cause of this unexpected increase and to reduce method variability, a risk-based statistical investigation was performed to identify potential factors which could be responsible for these effects. Factors identified by the risk assessment were investigated using a series of designed experiments to gain a greater understanding of the method. The increase of the level of Form 3 in the standard was primarily found to correlate with the number of repeat analyses, an effect not previously reported in SSNMR literature. Differences in data processing (phasing and linewidth) were found to be responsible for the variability in the method. After implementing corrective actions the variability was reduced such that the level of Form 3 was within an acceptable range of ±1% w w⁻¹ in fresh samples of API.     

HL-2A 装置中高能量捕获电子鱼骨模不稳定性研究

结合HL-2A 装置的参数,在电子回旋共振加热(ECRH)离(在)轴加热的情况下,研究高能量捕获电子驱动的鱼骨模不稳定性。数值结果表明,高能量电子极向比压β_h 大于某一个比压阈值β_h,crit 时,鱼骨模会被高能量电子激发,其频率随高能量电子极向比压的增大而缓慢增加且与高能量电子的环向进动频率一致;比压阈值β_h,crit 随着高能量电子密度剖面峰化程度的增加而减小,但当密度剖面增大到一定值时比压阈值β_h,crit 趋近于一个常数。此外,还分析了箍缩角和扰动能对鱼骨模实频和增长率的影响。发现在箍缩角α₀ =1附近增长率有一极小值,表明高能量勉强通行电子对鱼骨模具有稳定作用;而扰动能 δWˆ_c增大时,鱼骨模表现出实频变大而增长率变小的特征,这表明了本底等离子体对鱼骨模有一定的稳定效果。     

环位形下鱼骨模驱动快离子输运的数值模拟研究

考虑包含动理学效应的鱼骨模结构,使用导心轨道程序 ORBIT,在磁面坐标下研究了不同的扰动模 幅度、频率对快离子再分布的影响,并分析了粒子与扰动发生共振的条件。模拟得出,鱼骨模扰动会使快离子在 实空间、相空间中发生再分布,芯部( ψ_p/ψ _w≤0.2 ,ψ_p 为极向磁通,ψ_w 为最后一个闭合磁面的磁通)快离子密 度下降约 20%,中间磁面位置上( ψ_p/ψ _w≥0.2,ψ_p/ψ _w≤ 0.6)的快离子密度增加约 7%;通过扫描频率发现,相空间中快 离子的再分布对模式频率敏感,并分析了快离子与鱼骨模扰动共振的条件。     

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结合HL-2A 装置的参数,在电子回旋共振加热(ECRH)离(在)轴加热的情况下,研究高能量捕获电子驱动的鱼骨模不稳定性。数值结果表明,高能量电子极向比压βh 大于某一个比压阈值βh,crit 时,鱼骨模会被高能量电子激发,其频率随高能量电子极向比压的增大而缓慢增加且与高能量电子的环向进动频率一致;比压阈值βh,crit 随着高能量电子密度剖面峰化程度的增加而减小,但当密度剖面增大到一定值时比压阈值βh,crit 趋近于一个常数。此外,还分析了箍缩角和扰动能对鱼骨模实频和增长率的影响。发现在箍缩角α0 =1附近增长率有一极小值,表明高能量勉强通行电子对鱼骨模具有稳定作用;而扰动能 δWˆc增大时,鱼骨模表现出实频变大而增长率变小的特征,这表明了本底等离子体对鱼骨模有一定的稳定效果。     

Flavor mechanism of micro-nanoparticles and correlation analysis between flavor substances in thermoultrasonic treated fishbone soup

To study the physicochemical properties of micro-nanoparticles (MNPs) in thermoultrasonic treated fishbone soup, it was subjected to ultra-filtration with a 100 kDa ultrafiltration membrane to obtain large MNPs (LMNPs) and small MNPs (SMNPs). LMNPs and SMNPs were treated with force-breakers, and the interactions of the MNPs with five characteristic volatile compounds were investigated. LMNPs covered most proteins (222.66 mg/mL) and fatty acids (363.76 mg/g), while SMNPs was mostly soluble small molecules with taste substances like total free amino acids (85.26 mg/g), organic acids (2.55 mg/mL), and 5′-nucleotides (169.17 mg/100 mL). The stability of LMNPs is significantly higher than raw bone soup, and SMNPs can exist stably in the solution. Correlation analysis between flavor substance content and flavor suggested that the overall flavor profile of halibut bone soup was closely related to the content changes of 72 significant influence variables. The binding of LMNPs to characteristic flavor compounds was largely affected by hydrophobic interactions, hydrogen bonds, and ionic effects. While the binding of SMNPs to characteristic flavor compounds was largely determined by hydrophobic interaction and hydrogen bonding. This study explores the characteristics of MNPs and provides the possibility to clarify the interaction mechanism between MNPs and flavor.