Multivariate analysis of non-homogeneous peaks in liquid chromatography

Summary The effects of concentration, separation and spectral similarity as factors influencing the accuracy of iterative target testing factor analysis (ITT-FA) are investigated for three component systems by the application of analysis of variance (ANOVAR). ANOVAR is applied over a range of peak separations to map the changing effects of the three factors with increasing overlap. Two error responses were measured and analysed, (a) Relative cluster error (RCE) a measure of the error over all peaks in a cluster and (b) Relative peak error (RPE) the error of an individual peak. Multicomponent analysis (MCA) a method requiringa priori spectral information, is used as a referee method for ITT-FA.     

Monte Carlo simulation of spatial distribution of X rays in multifilm targets. III: optimum design as applied to W/Al‐film targets

The brightness of the X‐ray source in a W/Al‐film target used for X‐ray projection microscopy was studied by an approach using the Monte Carlo simulation. Since continuous X rays generated in a thin film have a specific angular distribution of emission, the brightness of the continuous X‐ray source cannot simply be estimated on the assumption that the angular distribution is homogeneous. The newly developed approach using the Monte Carlo simulation enables the evaluation of the effective source size, angular distribution, and brightness of a continuous X‐ray source with sufficient accuracy that it leads to the optimum design of a high‐brightness X‐ray source for uses such as X‐ray projection microscopy. The Monte Carlo calculations were performed for W(Δz)/Al (200 µm)‐film targets with different thicknesses of W film, Δz, under bombardment of 60 kV electrons. The results have suggested an optimum design consisting of a W (2 µm)/Al (200 µm)‐film target as most promising for providing an X‐ray source of higher brightness than the W (5 µm)/Al (200 µm)‐film target, which has already been in practice for X‐ray projection microscopy. Copyright © 2006 John Wiley & Sons, Ltd.     

神光-Ⅱ装置三倍频实验中靶场单元技术的改进

 主要介绍为了满足神光-Ⅱ高功率激光装置三倍频光（351nm，3ω）的物理实验要求，靶场三倍频模拟光源和瞄准监视系统两个主要单元技术的改进，即三倍频模拟光源由基频光（1 053nm，3ω）通过腔外的KTP+BBO晶体倍频获得，再经八路分光系统和主激光耦合；瞄准监视系统由透射式光学系统改进为反射式光学系统，避免原系统存在较大的色差，提高瞄准精度。     

面向无人机航拍图像的多尺度目标检测研究

针对无人机航拍图像背景复杂、小目标占比高且分布不均导致的现有算法精度不佳等问题,提出了一种面向无人机航拍图像的多尺度目标检测网络VTO-YOLOv8。首先,采用WIoU v3作为边界框回归损失函数,并使用明智的梯度分配策略,这一策略将使网络更加关注普通质量样本,从而提高其定位能力;其次,设计四层T-BiFPN结构,加强浅层特征和深层特征的融合;此外,设计C2f-DBB多分支模块,在不增加计算量的前提下,提升检测性能;同时,使用聚焦调制模块,加强不同尺度信息的交互。实验结果表明,网络在Visdrone2019数据集上相较基准模型在mAP50和mAP指标上分别提高了9.0%和5.9%,同时参数降低了22.6%,可更好地应用于无人机航拍目标检测中。     

融合GMS检测和置信度判别的TLD目标跟踪

针对目标在遮挡、尺度变化等复杂场景下易产生模型漂移问题,基于跟踪学习检测(TLD)框架提出一种结合基于网格的运动统计(GMS)检测和置信度判别的长时目标跟踪算法.首先在跟踪模块中采用快速判别尺度空间的相关滤波器(fDSST)作为跟踪器,利用位置滤波器和尺度滤波器对上一帧目标进行位置与尺度的判别,并依据TLD算法中跟踪模...     

Discovery of Quinacrine as a Potent Topo II and Hsp90 Dual-Target Inhibitor,Repurposing for Cancer Therapy

Topo II and Hsp90 are promising targets. In this study, we first verified the structural similarities between Topo IIα ATPase and Hsp90α N−ATPase. Subsequently, 720 compounds from the Food and Drug Administration (FDA) drug library and kinase library were screened using the malachite green phosphate combination with the Topo II-mediated DNA relaxation and MTT assays. Subsequently, the antimalarial drug quinacrine was found to be a potential dual−target inhibitor of Topo II and Hsp90. Mechanistic studies showed that quinacrine could specifically bind to the Topo IIα ATPase domain and inhibit the activity of Topo IIα ATPase without impacting DNA cleavage. Furthermore, our study revealed that quinacrine could bind Hsp90 N−ATPase and inhibit Hsp90 activity. Significantly, quinacrine has broad antiproliferation activity and remains sensitive to the multidrug−resistant cell line MCF−7/ADR and the atypical drug−resistant tumor cell line HL−60/MX2. Our study identified quinacrine as a potential dual−target inhibitor of Topo II and Hsp90, depending on the ATP−binding domain, positioning it as a hit compound for further structural modification.     

基于梯度相关性的红外微弱目标检测

提出了一种新的基于空域梯度相关性的图像杂波自适应预测算法.该算法能显著改善微小目标的邻域信杂比(SCNR).试验证明,本算法相对于已有的多种算法,有着更好的性能.对微弱目标SCNR的增益相对于传统算法提高3 dB以上.本文还引入了一种基于统计分析的微小目标检测算法.该算法考虑了微小目标在图像集成时的重叠特性,能在不增加系统运算负荷的情况下,获得更高的检测概率,相对于不考虑重叠特性的算法,在虚警概率小于10-4时,假设重叠系数为3,SCNR为4 dB,系统检测概率从小于20%,大幅提高到80%.理论分析及仿真表明,本文提出的检测系统存微小目标枪测中,具有很高的实用性.系统在原始信号的邻域信杂比(SCNR)小于0 dB的情况下,能有效检测出目标,在采用10帧集成检测,目标像素重叠参数为5的情况下,虚警概率小于10-7,系统检测概率大于80%,虚警概率小于10-4,系统检测概率大于95%. 标在图像集成时的重叠特性,能在不增加系统运算负荷的情况下,获得更高的检测概率,相对于不考虑重叠特性的算法,在虚警概率小于10-4时,假设重叠系数为3,SCNR为4 dB,系统检测概率从小于20%,大幅提高到80%.理论分析及仿真 明,本文提出的检测系统存微小目标枪测中,具有很高的实用性.系统在原始信号的邻域信杂比(SCNR)小于0 dB的情况卜,能有效检测出目标,在采用10帧集成检测,目标像素重叠参数为5的情况下,虚警概率小于10-7,系统检测概率大于80%,虚警概率小于10-4,系统检测概率大于95%. 标在图像集成时的重叠特性,能在不增加系统运算负荷的情况下,获得更高的检测概率,相对于不考虑重叠特性的算法,     

微球动态涂敷状态实时监测光学系统的设计

 介绍了一种可用于实时监测直径0.2～1.0 mm激光核聚变靶球涂敷状态的光学系统的设计,系统采用环形LED照明系统以适合特殊的照明要求,用Petzval型物镜使500 mm处的微球清晰成像于CCD像面上,CCD输出的图像电信号经图像采集卡转换成数字信号,最后该数字信号由计算机进行处理,实现了系统对靶球膜层涂敷作业的自动监控,大大提高了涂敷效率。所设计的系统轴上点最大弥散斑直径为12.6 mm,轴外最大弥散斑直径为15.8 mm,整个视场的像质比较均匀,分辨率较高,对于波长522 nm的光线,场曲和畸变分别小于15 mm和0.012%,像质优良。     

CO2,O2,CF4液体微滴喷射靶激光等离子体光源光谱

基于软X射线辐射计量和极紫外投影光刻(EUVL)应用,研制了一台使用纳秒激光器的液体微滴喷射靶激光等离子体(LPP)极紫外光源。该光源由一个可连续控温的不锈钢电磁喷气阀门、YAG激光器和能同步控制喷气阀门和激光器的脉冲发生器组成。使用液氮作致冷剂,控温范围77～473 K。对于足够高的背景气压和低的阀门温度,当气体经过阀门脉冲式地喷入真空靶室内时,气体经过气-液相变碎裂成大量的液体微滴形成液体微滴喷射靶。首先,依据非相对论量子力学理论,使用原子光谱分析常用的Cowan程序,计算了O2,CO2和CF4等几种液体在1011～1012W.cm-2激光功率密度下可能相应产生的O4 ,O5 ,O6 ,O7 ,F5 ,F6 和F7 离子的电偶极辐射跃迁波长和跃迁概率。其次,在激光焦点功率密度为8×1011W.cm-2时,测量了CO2,O2,CF4液体微滴喷射靶在6～20 nm波段的光谱。理论计算结果与实验结果相比较,得出了所测量谱线的电偶极辐射跃迁波长和跃迁概率以及跃迁能级所应归属的组态和光谱项。     

日盲型紫外探测系统中目标定位的研究

为了研究日盲型紫外探测中的目标定位,设计了1套紫外探测实验系统。提出了1种基于目标图像的定位算法,通过确定目标在像平面上的位置,计算目标方位角。对系统及算法进行了理论分析和实验验证。以氘灯为目标的紫外光源,探测系统在30m处取得了0.5°的方位角测量精度。结果表明,该定位算法是可行的。这一结果对进一步开展远距离实验、完善系统是有帮助的。