微接触印刷法制造聚合物多层次准三维立体微结构

直接用聚合物稀溶液作为“印墨”进行微接触印刷,制作了诸如聚苯乙烯和聚甲基丙烯酸甲酯等聚合物的微细结构,通过重复交叉盖印得到多层次准三维立体微结构,并用可聚合的双(甲苯磺酸)-2,4-己二炔-1,6-二醇脂的丙酮稀溶液作微接触印刷,观察了微条纹上的聚合.对聚合物溶液的微接触印刷的过程中溶剂挥发等因素的影响进行了观察分析,结果表明,溶剂挥发时间对微图形的准确复制是十分重要的,过长或过短的溶剂挥发时间都不利于得到清晰精确的微结构.     

2-(3’,4’-二羧基苯氧基)苯甲酸配体桥联的锌(Ⅱ)配合物的合成、结构及荧光性质

以2-(3’,4’-二羧基苯氧基)苯甲酸(H3DPBA)和1,3-二(4-吡啶基)-丙烷(bpp)为配体,与Zn(Ac)2通过水热反应,获得了一维链状配合物Zn(DPBA)(bpp)。该配合物的一个不对称单元包括一个Zn(Ⅱ)离子,一个DPBA配体和一个bpp配体。Zn(Ⅱ)离子与四个氧原子及一个氮原子配位,其配位数为5。固态配合物在375nm处出现强的发射峰,来自于配体的π~*—π跃迁。与配体的荧光发射光谱比较,配合物的荧光发射峰发生了蓝移,而且配合物的荧光发射强度有大幅度增强。讨论了配合物在常见溶剂中和金属阳离子中的荧光性质。实验结果表明不同有机小分子或不同金属阳离子对配合物的荧光强度有不同程度的影响,有机小分子硝基苯和Fe~(3+)使配合物荧光猝灭,该Zn(Ⅱ)-配合物可用于硝基苯的检测以及水和乙醇体系中Fe~(3+)的检测。     

采用可见/近红外光谱检测大麦叶片过氧化氢酶与过氧化物酶含量的研究

采用可见/近红外光谱对丙酯草醚胁迫下大麦叶片过氧化氢酶(catalase, CAT)与过氧化物酶(peroxidase, POD)含量预测进行研究。对500～900 nm光谱采用移动平均法(moving average, MA)11点平滑方法进行预处理。采用蒙特卡罗-偏最小二乘法(monte carlo-partial least squares, MCPLS)方法分别对于CAT与POD的含量预测剔除7个与8个异常样本。基于全部光谱建立了CAT与POD含量预测的PLS,最小二乘支持向量机(least-squares support vector machine, LS-SVM)与极限学习机(extreme learning machine, ELM)模型,ELM模型对CAT含量预测效果最好,建模集相关系数(correlation coefficient of calibration, R_c)为0.916,预测集相关系数R_p为0.786;PLS模型对POD含量预测效果最佳,R_c为0.984,R_p为0.876。采用连续投影算法(successive projections algorithm, SPA)算法分别为CAT与POD预测选择了8个与19个特征波长,基于特征波长建立的PLS,LS-SVM与ELM模型中,ELM模型对CAT与POD含量预测效果均最佳,CAT含量预测的相关系数为R_c=0.928,R_p=0.790;POD含量预测的相关系数R_c=0.965,R_p=0.941。基于全谱与基于特征波长的回归分析模型预测效果相当,且对POD含量的预测效果优于对CAT含量的预测效果,而这需要进一步研究以得到精度和稳定性更高的预测模型。研究结果表明,采用可见/近红外光谱结合化学计量学方法可以实现对除草剂胁迫下大麦叶片CAT与POD含量的预测。     

基于拓扑结构的碱金属化合物摩尔磁化率的支持向量回归研究

基于经典电动力学导出的表征简单离子磁化率的磁性点价g_i所构建的分子磁性连接性指数?^mF及45种碱金属化合物的摩尔磁化率χ_m的实测数据集,利用粒子群寻优的支持向量回归（SVR）方法,建立了基于⁰F和¹F的碱金属化合物χ_m的预测模型,并与基于多元线性回归（MLR）模型的计算结果进行了比较.结果显示,基于9次交叉验证的SVR模型预测的平均绝对误差、平均相对误差绝对值以及均方根误差均比MLR模型小,表明SVR模型的回归预测能力优于MLR.研究表明,磁性连接性指数^mF是一种合适的分子描述符,SVR是一种预测碱金属化合物χ_m的有效方法. 关键词： 碱金属化合物 摩尔磁化率 支持向量回归 预测     

Spin-peierls transition in dimerized stacks of anion-radical salt (N-Me-2,5-di-Me-Pz)(TCNQ)2, (Pz is pyrazine)

An anion-radical salt (ARS) (N-Me-2,5-di-Me-Pz)(TCNQ)₂, where Pz is pyrazine, was synthesized and its crystal structure was resolved. X-ray diffraction experiments on single crystals were performed. Heat capacity was measured in the temperature range from 2 to 300 K. Magnetisation and magnetic susceptibility were measured in the temperature range from 2 to 300 K and the low-temperature part was measured in magnetic fields from 5 mT to 5 T. The experimental results were explained in terms of dimerized Heisenberg spin chain model. Numerical calculations were performed and compared with experimental data.     

ICP-AES测定钾石盐中的硫酸根离子

在选定的最佳条件下,样品直接溶解后采用ICP-AES测定钾石盐中硫酸根离子的含量,其最终检测结果与化学法测定结果一致。该方法简便、快速、线性范围宽、测量稳定。回收率为89.0%—102.0%。     

基于等概率符号分析方法计算互信息确定延迟时间

用互信息函数确定混沌时间序列相空间重构最佳延迟时间.针对常规符号分析方法计算互信息准确度不高的缺陷,提出等概率符号分析方法计算互信息,即对时间序列按值域大小重排列,再对重排后的序列进行等概率分割,分割的组数由分组经验公式确定,然后取每组的边界值组成符号分析方法的临界点集合进行计算.通过对Lorenz方程和强迫Brusselator振子进行仿真实验,得到的最佳延时与Fraser等概率分格子法得到的结果一致,而算法上更容易实现,证明方法有效.     

矿山多源遥感图像像点位移测试系统设计

针对矿山地形的起伏变化影响对其进行分析研究的准确性,提出矿上多源遥感图像像点位移测试系统的设计方法。结合GPS定位原理,选取遥感图像上某一时刻点作为测试点,对拍摄得到的矿山图像和电子测试系统各触点之间的距离进行计算,进而得到测试点具体坐标位置,将其与测试点真实现场坐标相对比,实现矿山多源遥感图像像点位移的测试。通过实验证明,所设计的测试系统可以高精度实现对遥感图像像点位移的测试,有效减小了矿山地形变化带来的遥感图像研究误差。     

In situ identification of organic components of ink used in books from the 1900s by atmospheric pressure matrix assisted laser desorption ionization mass spectrometry

Transport of N, O, and Ti during dc magnetron sputtering deposition of nanoscopic TiN/Ti and TiN structures on plasma nitrided M2 tool steel, as well as transport of metallic species composing the plasma nitrided steel substrates were investigated. N and O depth distributions were determined with subnanometric resolution using narrow resonant nuclear reaction profiling, whereas Ti was profiled, also with subnanometric depth resolution, by medium energy ion scattering. The surface elementary compositions of the TiN/Ti/nitrided steel and TiN/nitrided steel structures were determined by low energy ion scattering. The chemical compounds formed during deposition were accessed by X-ray photoelectron spectroscopy, indicating the presence of TiN, TiO₂, Ti oxynitrides, as well as other metallic nitrides and oxynitrides, but no metallic Ti was observed. Owing to the observed intensive atom mobility, the compositions of the deposited films on plasma nitrided steel structures varied continuously on a nanoscopic scale, from the core of the steel substrate to the bulk of the stoichiometric TiN films. The Ti interlayer assists interdiffusion of all species, in contrast to the TiN film layer, which is known to be a diffusion barrier. The improved adhesion of TiN hard coatings to plasma nitrided steel under working conditions is discussed in terms of the gradual compositional change around the interfaces and the atomic mobility during their formation.