基于Matlab GUI的微观化学反应过程可视化设计

基于准经典轨线方法和Matlab的GUI技术,我们开发设计了将a+bc三原子基元化学反应的碰撞过程可视化的动力学模拟程序,详细介绍了准经典轨线方法的基本原理、碰撞过程动力学信息的抽取和图形用户界面制作过程,并以典型反应F+HCl→Cl+HF为例展示了程序运行的结果。该程序可以将原子-双原子分子碰撞过程及碰撞的结果直观生动地通过动画的形式展现出来。学生也可以通过图形用户界面进行人机交互,从多个角度实时观察参与碰撞的原子、分子状态随时间的演化过程及结果。这有助于学生理解基元化学反应复杂的反应机理,加深对微观化学反应过程的感性认识。     

大豆水分含量的高光谱无损检测及可视化研究

采用近红外高光谱成像技术对大豆水分含量进行快速无损检测,实现大豆水分含量可视化。采集了96个不同品种大豆样本在900～2 500 nm的高光谱图像,采用直接干燥法测量每个大豆样品的水分含量。利用系统自带的HSI Analyzer软件提取图像感兴趣区域（ROI）的平均光谱信息,代表样品的光谱信息。利用SPXY算法划分样品校正集和预测集,并保留938～2 215 nm波段范围内的光谱数据。采用移动平滑（moving average）、S-G平滑、基线校正（baseline）、归一化（normalize）、标准正态变量变换（standard normal variate,SNV）、多元散射校正（multiple scattering correction,MSC）、去趋势（detrending）共7种光谱预处理方法,发现Normalize方法处理后的PLSR模型效果较好。为了去除光谱冗余信息,简化预测模型,采用连续投影算法（SPA）、竞争性自适应加权算法（CARS）、无信息消除变量法（UVE）提取特征波长,其中SPA,CARS和UVE三种算法优选出14,16和29个波长,分别占总波长的6.5%,7.4%和13.4%。分别对938～2 215 nm波段光谱和特征波长建立预测模型,并将效果较优的模型与Normalize方法结合。建立的14种预测模型效果相比较,发现SPA算法筛选的特征波长建模预测效果较好,并优选出Normalize-SPA-PCR模型,模型的R２_C和Ｒ２_P值较高,分别为0.974 6和0.977 8,RMSEP和RMSECV值较低,分别为0.238和0.313,模型的稳定性和预测性较好,可以对大豆水分含量进行准确预测。将Normalize-SPA-PCR模型作为大豆水分含量可视化预测模型,计算高光谱图像每个像素点的水分含量,得到灰度图像,对灰度图像进行伪彩色变换,得到大豆水分含量可视化彩色图像。对预测集的24个大豆品种进行可视化处理,发现不同水分含量大豆的可视化图像颜色不同,水分含量变化对应的颜色变化较为明显。结果表明,高光谱成像技术结合化学计量学可以准确快速无损预测大豆水分含量,实现大豆水分含量可视化,为大豆收获、贮藏加工过程中水分含量检测提供了技术支持。     

Efficient Global Optimization of Expensive Black-Box Functions

In many engineering optimization problems, the number of function evaluations is severely limited by time or cost. These problems pose a special challenge to the field of global optimization, since existing methods often require more function evaluations than can be comfortably afforded. One way to address this challenge is to fit response surfaces to data collected by evaluating the objective and constraint functions at a few points. These surfaces can then be used for visualization, tradeoff analysis, and optimization. In this paper, we introduce the reader to a response surface methodology that is especially good at modeling the nonlinear, multimodal functions that often occur in engineering. We then show how these approximating functions can be used to construct an efficient global optimization algorithm with a credible stopping rule. The key to using response surfaces for global optimization lies in balancing the need to exploit the approximating surface (by sampling where it is minimized) with the need to improve the approximation (by sampling where prediction error may be high). Striking this balance requires solving certain auxiliary problems which have previously been considered intractable, but we show how these computational obstacles can be overcome.     

New tools and resources in metabolomics: 2016–2017

Rapid advances in mass spectrometry (MS) and nuclear magnetic resonance (NMR)‐based platforms for metabolomics have led to an upsurge of data every single year. Newer high‐throughput platforms, hyphenated technologies, miniaturization, and tool kits in data acquisition efforts in metabolomics have led to additional challenges in metabolomics data pre‐processing, analysis, interpretation, and integration. Thanks to the informatics, statistics, and computational community, new resources continue to develop for metabolomics researchers. The purpose of this review is to provide a summary of the metabolomics tools, software, and databases that were developed or improved during 2016–2017, thus, enabling readers, developers, and researchers access to a succinct but thorough list of resources for further improvisation, implementation, and application in due course of time.     

形象化教学方法在药学专业化学类课程中的应用

In view of the complex knowledge points and some abstract theories of pharmaceutical chemistry courses, the application of visualized teaching methods to present important knowledge points in a vivid way can enhance the teaching effect and stimulate students' interest in learning. Based on the authors' teaching and research work, this article summarizes the application of figurative teaching methods such as metaphor and analogy in inorganic chemistry and medicinal chemistry courses.     

3-T MR-guided brachytherapy for gynecologic malignancies

Gynecologic malignancies are a leading cause of death in women worldwide. Standard treatment for many primary and recurrent gynecologic cancer cases includes external-beam radiation followed by brachytherapy. Magnetic resonance (MR) imaging is beneficial in diagnostic evaluation, in mapping the tumor location to tailor radiation dose and in monitoring the tumor response to treatment. Initial studies of MR guidance in gynecologic brachytherapy demonstrate the ability to optimize tumor coverage and reduce radiation dose to normal tissues, resulting in improved outcomes for patients.     

竖直环形通道内液氮自然循环沸腾可视化实验研究

采用基于高速摄像手段的可视化方法研究了竖直环形通道内的液氮自然循环沸腾过程,建立了汽泡脱离直径及汽泡脱离频率的实验关联式,以新建方程结合双流体模型进行了数值计算。与实验数据的对比表明,建立的实验关联式对于液氮自然循环沸腾过程中的汽泡脱离直径及汽泡脱离频率具有很好的预测精度。     

量子点比率荧光探针研究进展

量子点(QDs)是一种纳米发光粒子,具有优异的发光性能,在太阳能利用、荧光检测等方面具有广阔的应用前景。QDs与另一荧光团复合可构建比率荧光探针,实现可视化检测目标物并且提高了检测灵敏度。本文主要对QDs比率荧光探针的种类、构建方法和应用领域的研究进展进行综述,并对其中的不足进行分析,以期为研发具有优异性能的比率荧光探针提供借鉴。     

Visualization of scavenging flow in the design of small two-stroke engines

An experimental test rig is presented, which enables visual examination of the internal flow of piston ported two-stroke cylinders. Similarity laws are applied to design the layout of the set-up. The reasons to use a liquid to represent the scavenging fluid are explained. Experiments are carried out which visualize the scavenging flow inside the cylinder. Colours play an important role in the visualization of flows. Careful selection of the dyes and the particular arrangement of different colours produce features of the three-dimensional and unsteady flow under investigation. The potential for future investigations to become an integrated part of the design process of small two-stroke engines is demonstrated.     

Transversal vibrations of the axially moving sandwich belts

Inspired by literature on free transversal vibrations of one axially moving belt, we derive and solve analytically coupled partial differential equations of the transversal vibrations of an axially moving sandwich double-belt system. A numerical experiment and visualization are carried out.