快点火锥壳靶内爆自发光图像数据处理

为研究快点火预压缩过程中导引锥对压缩靶丸芯部辐射对称性的影响,在神光Ⅲ原型上开展了快点火预压缩的自发光测量实验。采集了相同长度黑腔中不同类型靶丸的内爆自发光图像和不同长度黑腔中同类靶丸的内爆自发光图像,利用最小二乘椭圆拟合方法对芯部的自发光半峰值强度等高线进行椭圆拟合,通过椭圆特征来分析靶丸在最强发光时刻的压缩对称性。分析结果表明：导引锥的存在会使发光区域沿着赤道方向拉长,降低了压缩对称性;有锥靶丸在1600 m黑腔内的形变小于在1500 m和1700 m黑腔内的形变,压缩对称性可以通过调整黑腔长度来控制。     

概率神经网络在高功率微波探测数据处理中的应用

为了更好地处理高功率微波探测过程中产生的样本数据,在深入分析高功率微波特性参数的基础上,建立一个高功率微波器件特征参数库,并结合概率神经网络系统建立了一个高功率微波探测预测模型。通过部分学习样本和非学习样本进行预测,预测结果证明该模型能够基本再现原始数据,同时,对非样本数据有着较好的预测能力。这一数据处理方法在处理复杂样本、模式分类和判别过程中具有较高的实用性和实时性,能够在高功率微波探测数据的数据分类、结果预测等方面得到较好的应用。     

CAEP XFEL波荡器束线初步物理设计

中国工程物理研究院计划开展XFEL光源的研制,主要通过电子束在波荡器中的辐射特性产生硬X射线。根据理论分析和数值模拟,在电子束最高能量可达12 GeV的实际条件下,初步设计了一条间隙可调的真空外波荡器束线,波荡器分为25段,每段长3.86 m,间隙7~10 mm,周期长度25.4 mm,磁场0.636~1.03 T,束线总长120 m左右,辐射光子能量为3~25 keV。     

离焦激光直写的线宽稳定方法

为了提高激光直写加工衍射光学元件时的线条质量,提出一种离焦激光直写的线宽稳定方法.该方法通过同时调节激光功率和离焦量,使光刻胶的曝光阈值处于线宽对曝光量的变化率较小位置,从而可以弱化线宽对实际曝光量或光刻胶阈值等变化的敏感度,提高利用离焦方法进行衍射光学元件制作时的线宽稳定性.推导了稳定线宽后的光功率控制模型和线宽模型,模型中的变量仅为离焦量,降低了光功率控制的复杂性.利用632.8 nm的He-Ne激光和NA-0.1的物镜在CCD上对采用该方法后的离焦线宽模型进行验证,实验结果与理论模型吻合较好.该方法对于线宽稳定度较高的衍射光学元件制作具有重要价值.     

IVDAS: an interactive visual design and analysis system for image data symmetry detection of CNN models

Journal of Visualization - Convolutional neural networks (CNNs) have achieved breakthrough performance in image recognition and classification. However, it is still a challenge for CNNs to classify...     

Recent advances in electrochemical sensors for antibiotics and their applications

The abuse of antibiotics will cause an increase of drug-resistant strains and environmental pollution,which in turn will affect human health.Therefore,it is important to develop effective detection techniques to determine the level of antibiotics contamination in various fields.Compared with traditional detection methods,electrochemical sensors have received extensive attention due to their advantages such as high sensitivity,low detection limit,and good selectivity.In this mini review,we summarized the latest developments and new trends in electrochemical sensors for antibiotics.Here,modification methods and materials of electrode are discussed.We also pay more attention to the practical applications of antibiotics electrochemical sensors in different fields.In addition,the existing problems and the future challenges ahead have been proposed.We hope that this review can provide new ideas for the development of electrochemical sensors for antibiotics in the future.     

Morphology controllable conjugated network polymers based on AIE-active building block for TNP detection

Luminescent conjugated network polymer is one of the most promising chemo-sensors owing to their good chemical/optical stability and multiple functionalization.Herein,three conjugated network polymers were prepared by using aggregation-induced emission active 1,1,2,2-tetrakis(4-formyl-(1,1'-biphenyl))-ethane(TFBE) unit as monomer and hydrazine as linker.Through regulating the synthetical condition,the polyme ric network can form either unifo rm two-dimensional azine-linked nanosheets(ANS),conjugated microporous polymers(A-CMP) or covalent organic frameworks(A-COF).All of these polymers exhibited good stability and high fluorescence quantum efficiency with the quantum yield of6.31% for A-NS,5.26% for A-CMP,and 5.80% for A-COF,as well as fast and selective fluorescence quenching response to 2,4,6-trinitrophenol(TNP).And the best TNP sensing performance with the Stern-Volmer constants(K_(sv)) values up to 8 × 10~5 L/mol and a detection limit of 0.09 μmol/L was obtained for A-NS.The study explores various strategies to construct conjugated polymers with different nanoarchitectures based on the same building block for sensitive detection of explosives.     

柔红霉素与DNA作用的序列特异性研究

采用紫外-可见光谱法和紫外-可见光谱电化学法研究了柔红霉素(DNR)与不同寡聚核苷酸之间的相互作用.结果表明,DNR优先作用于寡聚核苷酸的CpG位点,然后是ApG和ApC.因为DNR可与鸟嘌呤之间形成3个氢键.与双链寡聚核苷酸作用时,DNR最先插入的位点是(CpG)₂碱基对之间,其次是(TpG)(CpA)和(GpC)(ApC)碱基对之间.当DNR与存在未配对G碱基的DNA链作用时,因游离的DNR量增加使其电化学活性增加,导致DNA构象和构型的变化,使DNA生理功能受到损伤,DNA碱基增色效应显著上升.此法可用于G碱基未配对DNA链的检测.     

链酚胺型配体锌(Ⅱ)配合物模拟碳酸酐酶研究

合成了酚胺型链状配体,N,N'-二(2-羟基苄基)丙二胺(H~2L)及其Zn(Ⅱ)配合物(ZnL),通过元素分析、IR和^1HNRM等手段进行了表征。采用pH电位滴定法,在25℃±0.1℃,I=0.1mol·dm^-^3(KNO~3)条件下,测定了配体的质子化常数以及配体与金属离子Zn(Ⅱ)配位反应平衡常数。讨论了配体与金属离子Zn(Ⅱ)的配位情况,得到了配位酚羟基的解离常数。运用分光光度法,在25℃±0.1℃,I=0.1mol·dm^-^3(KNO~3)条件下,在pH=5.5～9.0(50mmol·dm^-^3缓冲溶液)范围内,研究了配合物作为碳酸酐酶模拟物催化对-硝基苯酚乙酸酯(NA)水解动力学,得到了NA酯水解的配合物催化速率常数k~N~P。实验结果表明,ZnHL^+的配位酚羟基的解离常数pK~a为6.83;催化速率常数k~N~P与pH之间不存在Sigmoidal型曲线关系,而是在pH值中性附近有最大值,ZnHL^+对NA酯水解有很好的催化效果,并且采取双重催化机理,是碳酸酐酶很好的模拟物。     

Synthesis of Some Novel 3,6‐Bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole Derivatives

The cyclization of 1‐amino‐2‐mercapto‐5‐[1‐(4‐ethoxyphenyl)‐5‐methyl‐1,2,3‐triazol‐4‐yl]‐1,3,4‐triazole which was synthesized from p‐ethoxyaniline with various triazole acid in absolute phosphorus oxychloride yields 3,6‐bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole derivatives 9a?j , and their structures are established by MS, IR, CHN and ¹H NMR spectral data.