中药指纹图谱的融合技术

中药指纹图谱作为中药材真伪鉴别及质量控制的有效手段,具有整体、宏观和模糊分析等特点。高效液相色谱是指纹图谱研究的主流方法,在中药质量控制中具有重要地位。针对栀子药材而言,包括3类主要物质：环烯醚萜苷类、有机酸类和色素类。仅采用一个特征波长下的色谱指纹图谱无法对栀子药材进行整体表达和全面评价。为此,     

One-pot synthesis of N-methylimidazolium-based porous polymer monolith for capillary electrochromatography via free radical copolymerization and quaterisation

One-pot synthesis of porous polymer monolith decorated with N-methylimidazolium in a capillary was described. The polymer matrix was synthesized by in situ copolymerization and quaterization of 3-chloro-2-hydroxylpropyl methacrylate (CHPMA), ethylene dimethacrylate (EDMA), and N-methylimidazole (N-MIz). The influencing factors including amount of cross-linkers, composition of porogenic solvents, and polymerization temperature on the formation of the monolithic column were investigated. The monolithic column exhibited high column efficiency for thiourea, up to 135 000 plates per meter, and phenylmethanol, up to 102 000 plates per meter. Different types of compounds including alkylbenzenes, phenols, and inorganic anions were successfully baseline separated by capillary electrochromatography (CEC). The separation of theses analytes on the column indicated typical reversed-phase and anion-exchange chromatographic retention mechanism.     

HO3+ 杂Ge-In-Sb-S玻璃陶瓷光谱特性

采用熔融淬冷法和热处理工艺制备了系列掺Ho3+的透明G eS2-In2S3-Sb2S3硫系玻璃陶瓷.测试了Ho3掺杂的基质玻璃和玻璃陶瓷样品的密度、显微硬度、红外光谱以及在900 nm激光泵浦下的近红外及中红外荧光光谱.结果表明:热处理后样品析出的晶相为In2S3和Sb2S3颗粒的混合体,晶粒尺寸限制在～100 nm以...     

Surface modification of PDMS by surface-initiated atom transfer radical polymerization of water-soluble dendronized PEG methacrylate

The current paper reports the synthesis of a highly hydrophilic, antifouling dendronized poly(3,4,5-tris(2-(2-(2-hydroxylethoxy)ethoxy)ethoxy)benzyl methacrylate) (PolyPEG) brush using surface initiated atom transfer radical polymerization (SI-ATRP) on PDMS substrates. The PDMS substrates were first oxidized in H₂SO₄/H₂O₂ solution to transform the Si-CH₃ groups on their surfaces into Si-OH groups. Subsequently, a surface initiator for ATRP was immobilized onto the PDMS surface, and PolyPEG was finally grafted onto the PDMS surface via copper-mediated ATRP. Various characterization techniques, including contact angle measurements, attenuated total reflection infrared spectroscopy, and X-ray photoelectron spectroscopy, were used to ascertain the successful grafting of the PolyPEG brush onto the PDMS surface. Furthermore, the wettability and stability of the PDMS-PolyPEG surface were examined by contact angle measurements. Anti-adhesion properties were investigated via protein adsorption, as well as bacterial and cell adhesion studies. The results suggest that the PDMS-PolyPEG surface exhibited durable wettability and stability, as well as significantly anti-adhesion properties, compared with native PDMS surfaces. Additionally, our results present possible uses for the PDMS-PolyPEG surface as adhesion barriers and anti-fouling or functional surfaces in biomedical applications.     

微波辅助快速制备核-壳型尿苷印迹聚合物及其在线富集应用研究

采用微波辅助加热,以尿苷为模板分子,丙烯酰胺(AA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,快速制备尿苷印迹聚合物,聚合时间大大缩短,仅为传统加热的1/8.采用红外光谱和扫描电镜对印迹聚合物进行表征,结果表明二氧化硅表面成功包覆尿苷印迹壳层;该印迹聚合物颗粒分散均匀,印迹壳层厚度约为100 nm.将该印...     

Discrimination of Ganoderma lucidum according to geographical origin with near infrared diffuse reflectance spectroscopy and pattern recognition techniques

A rapid and nondestructive near infrared (NIR) method combined with chemometrics was used to discriminate Ganoderma lucidum according to cultivation area. Raw, first, and second derivative NIR spectra were compared to develop a robust classification rule. The chemical properties of G. lucidum samples were also investigated to find out the difference between samples from six varied origins. It could be found that the amount of polysaccharides and triterpenoid saponins in G. lucidum samples was considerably different based on cultivation area. These differences make NIR spectroscopic method viable. Principal component analysis (PCA), discriminant partial least-squares (DPLS) and discriminant analysis (DA) were applied to classify the geographical origins of those samples. The results showed that excellent classification could be obtained after optimizing spectral pre-treatment. For the discriminating of samples from three different provinces, DPLS provided 100% correct classifications. Moreover, for samples from six different locations, the correct classifications of the calibration as well as the validation data set were 96.6% using the DA method after the SNV first derivative spectral pre-treatment. Overall, NIR diffuse reflectance spectroscopy using pattern recognition was shown to have significant potential as a rapid and accurate method for the identification of herbal medicines.     

Dynamics of two elliptical particles sedimentation in a vertical channel: chaotic state

The LB-DF/FD method derived from the Lattice Boltzmann Method and direct forcing/fictitious domain method is used to numerically investigate the dynamics and interaction of two elliptical particles settling in an infinitely long channel. One particle (EP0) is initially kept horizontal (major axis perpendicular to sedimentation) for all simulations while the other's (EP1) orientation is varied. It is found that if EP1strays away from horizontality, the particles undergo transitions from a steady state to reach a chaotic state. Furthermore, there are two distinct chaotic states for the particle motion when EP1 orientation is varied, in which a turning point is observed to distinguish the two states.     

一类非线性矩阵方程对称解的双迭代算法

利用逆矩阵的Neumann级数形式,将在Schur插值问题中遇到的含未知矩阵二次项之逆的非线性矩阵方程转化为高次多项式矩阵方程,然后采用牛顿算法求高次多项式矩阵方程的对称解,并采用修正共轭梯度法求由牛顿算法每一步迭代计算导出的线性矩阵方程的对称解或者对称最小二乘解,建立求非线性矩阵方程的对称解的双迭代算法.双迭代算法仅要求非线性矩阵方程有对称解,不要求它的对称解唯一,也不对它的系数矩阵做附加限定.数值算例表明,双迭代算法是有效的.     

粗糙表面涂覆目标的太赫兹波散射特性研究

对具有涂覆层目标的太赫兹波段粗糙表面的散射特性进行了研究. 考虑到表面粗糙度的影响, 可先对反射系数进行修正, 再利用反射系数对等效电磁流进行修正, 得到粗糙涂覆表面的等效电磁流, 然后在物理光学方程的基础上得到粗糙表面涂覆目标的雷达散射截面; 最后进行图形电磁学可视化计算, 并采用Visual C++对模型进行OpenGL显示, 提取像素面元的有效信息对所得理论进行了仿真分析, 研究了不同入射角度、不同频率、不同介质、不同粗糙度和不同涂层厚度下的太赫兹波电磁散射特性, 得到了一些有参考价值的结论.     

热损伤奥克托金(HMX) 缺陷的X射线小角散射研究

奥克托金(HMX) 在温度作用下, 会发生热膨胀、 相转变、 热分解等物理、 化学变化, 导致在材料内部产生大量缺陷, 进而会对其宏观性能造成明显影响. 为了深入了解热损伤HMX内部的缺陷演化, 本文采用X射线小角散射和原子力显微技术研究了热损伤HMX的内部缺陷. 结果发现HMX在180 °C相变过程中散射曲线有明显的变化, 颗粒内部生成了大量10nm左右的孔洞, 随着加载时间延长, 其尺寸增大到25nm, 数量明显降低. 当HMX在190 °C、 200 °C保温5h时, 由于HMX热分解内部有新缺陷生成, 小角散射发现其尺寸约为5至8nm, 随着加载温度升高, 其数量增加.