热解吸-电喷雾离子源-三重四极杆质谱法快速筛查火锅底料和肉汤中非法添加罂粟壳

通过简单的金属探针直接接触火锅底料和肉汤表面采集待测物,经热解吸离子源进一步热解吸和电喷雾离子化,最终进入三重四极杆质谱检测器在多反应监测模式下进行定性分析,实现了火锅底料和肉汤中罂粟壳的现场实时快速检测。结果表明,设置热解吸温度为260℃,以0.1%甲酸水溶液（含10 mmol/L甲酸铵-乙腈（1:1,v/v）作为注射溶剂、注射泵流速为200 μL/h时,仪器响应值最优,灵敏度最高;5种生物碱中罂粟碱、那可丁、蒂巴因在火锅底料和肉汤中的检出限均为2 μg/kg,可待因、吗啡在火锅底料中的检出限为10 μg/kg,在肉汤中的检出限为5 μg/kg。该法与罂粟壳胶体金卡片快检试剂盒相比,灵敏度具有明显优势。应用该法对50批次市售火锅底料、肉汤等样品进行检测,发现1批次鸡汤含有那可丁、罂粟碱、蒂巴因和吗啡4种生物碱,与高效液相色谱-三重四极杆质谱法的检测结果一致。由此说明该方法具有无需样品制备和色谱分离的特点,是一种快速、绿色、环保的分析方法,能够满足对食品中罂粟壳的快速定性分析。     

利用自制装备测量液体表面张力系数

文章利用自制装备采用液膜气泡法在14℃条件下对肥皂液表面张力系数进行测量。利用实验室的装备采用拉脱法进行测量,证明自制装备可以较为准确的测出表面张力系数。     

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。     

Pressure-assisted thermal sterilization of soup

The overall efficiency of an existing scale-up pressure-assisted thermal sterilization (PATS) unit was investigated with regards to inactivation of Geobacillus stearothermophilus spores suspended in pumpkin soup. The PATS unit is a double pipe heat exchanger in which the soup is pumped into its inner high pressure tube and constrained by two high pressure valves, while steam is continuously passed through the annular region to heat the content. The technology is based on pressure generation by thermal expansion of the liquid in an enclosure. In this work, the addition of an air line to push the treated liquid food out of the existing PATS unit has improved the overall quality of the treated samples, as evidenced by achieving higher log reduction of the spores. Compared with thermal processing, the application of PATS shows the potential for lowering the thermal treatment temperature, offering improved food quality.     

微波消解-电感耦合等离子体质谱法测定养生保健汤料包中16种稀土元素

采用电感耦合等离子体质谱法测定养生保健汤料包中16种稀土元素。采用硝酸-过氧化氢混合液为消化剂对样品进行微波消解,利用电感耦合等离子体质谱法测定16种稀土元素。16种稀土元素的质量浓度在1.0~80μg·L-1范围内呈线性,检出限(3S/N)为0.1~1.7μg·kg-1。方法用于标准物质的分析,测定值与认定值相符。按方法分析样品做精密度试验,测定值的相对标准偏差(n=10)小于5%。方法用于测定12种养生保健汤料中稀土氧化物含量总和在0.127~0.984 mg·kg-1之间。     

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。     

Convectional and sedimentation dissipative patterns of Miso soup

Convectional and sedimentation dissipative patterns of Miso soup, one of the traditional Japanese soups, were observed in a Miso soup bowl, a green tea Ochawan (cup), a glass cup, a large glass bowl, and a large watch glass. When Miso soup was set in the substrates, the distorted Benard cells were soon observed after the initial irregular circulations, and the holes grew large at the cross points of the neighboring three Benard cells. The global integrated flow direction of convections at the liquid surface was from the center area toward the outside edge during the periods of formation of the distorted Benard cells. Meanwhile, the reversal of the global flow direction, from outward to inward, at the liquid surface took place. Furthermore, the inward flow at the surface, i.e., the outward flow at the bottom, was accompanied with the broad ring-like sedimentation patterns. The most plausible kinetic scheme of the change in the convectional patterns is proposed in this work.