三峡三期RCC围堰拆除爆破倾倒效果DDA模拟

三峡工程三期RCC围堰采用“以预置集中药室倾倒爆破为主、两端钻孔炸碎爆破为辅”的拆除爆破方案,其中预置集中药室的围堰爆破尤其令人关注.在围堰拆除爆破实施前,应用DDA程序对预置药室按设计顺序依次起爆后,形成围堰倾倒缺口以及围堰倾倒全过程进行了模拟.通过爆破实测振动监测资料分析,围堰倾倒的实际触地时间与模拟触地时间基本一致;通过爆破后水下地形测量,围堰倾倒的缺口形状、倾倒后的形态与模拟计算的结果也基本一致.证明运用DDA程序对三峡三期RCC围堰倾倒爆破效果的爆前预测是成功的,该方法对类似工程的爆破设计、施工和安全防护等具有积极的指导意义.     

Discrete-dipole approximation with surface interaction: Computational toolbox for MATLAB

We describe a MATLAB toolbox that utilizes the discrete-dipole approximation (DDA) method for modelling light interaction with arbitrarily-shape scatterers in free space as well with planar surface interaction (DDA-SI). The range of applicable models range from optical micromanipulation, plamonics, nano-antennae, near-field coupling and general light interaction with scatterers ranging from a few nanometers to several microns in size.     

Tuning the optical properties of Fe-Au core-shell nanoparticles with spherical and spheroidal nanostructures

Present research interest is to highlight on the manufacturing of core-shell nanoparticles because of core activity with unique properties and surface modification by a shell in the diverse fields (e.g. optoelectronic, catalysis and magneto-optics). In addition, the combined optical properties of magnetic-plasmonic core-shell NPs make them ideal candidates for many applications in biomedical fields. The influence of Fe-core and Au-shell for the formation of the core-shell viz. spherical and spheroidal nanostructures is studied using the discrete dipole approximation method. DDA is an approximation method and its accuracy is compared to Mie theory results for spherical core-shell NPs as Mie theory gives the exact solution to spherical targeted NPs. DDA calculations are further extended to spheroidal core-shell nanostructures. It is observed that the localized surface plasmon resonance (LSPR) peak position in considered core-shell nanostructures is enhanced by changing the cores and shell thickness in the core-shell spherical nanostructures and aspect ratio as well as shell thickness in spheroidal core-shell nanostructures. The absorption spectra are found between 363–788 nm wavelength ranges and can be tuned into UV-visible-near-infrared region of the electromagnetic (EM) spectrum in accordance with desired applications. It has been found that the Fe@hollow@Au and prolate core-shell nanostructures show enhancement to LSPR peaks, bandwidth and their corresponding intensities in comparison to other considered spherical and spheroidal core-shell nanostructures. Tunability in core size, shell thickness, aspect ratio, and configuration will open new potential uses of suitable magnetic-plasmonic core-shell nanostructures in cancer therapy, tissue engineering, drug delivery, and many more of biomedical fields.     

Comparison between the lab observations and DDA computations on the backscattering features of sphere-cone-oblate ice particles

Twenty sphere-cone-oblate ice particles are simulated for their backscattering observations in a microwave lab and calculations are done with the DDA method. The lab experiment and the DDA theory are briefly presented in this paper. The theoretical results are compared with the lab observations. It is shown that the theoretical results are consistent with the experimental data in general and that the backscattering ability of sphere-cone-oblate ice particles increases as the particle size parameter increases, and fluctuates in the so-called resonance region. The backscattering cross sections of sphere-cone-oblate ice particles depend not only on their sizes equivolume spherical radii R_e but also on their shapes. There is a statistically linear relationship between differential reflectivity Z_DR and the shape factor, 2a/h, which is the ratio of the horizontal scale to the vertical scale of a particle.     

Data processing pipelines for comprehensive profiling of proteomics samples by label-free LC-MS for biomarker discovery

Label-free quantitative LC-MS profiling of complex body fluids has become an important analytical tool for biomarker and biological knowledge discovery in the past decade. Accurate processing, statistical analysis and validation of acquired data diversified by the different types of mass spectrometers, mass spectrometer parameter settings and applied sample preparation steps are essential to answer complex life science research questions and understand the molecular mechanism of disease onset and developments. This review provides insight into the main modules of label-free data processing pipelines with statistical analysis and validation and discusses recent developments. Special emphasis is devoted to quality control methods, performance assessment of complete workflows and algorithms of individual modules. Finally, the review discusses the current state and trends in high throughput data processing and analysis solutions for users with little bioinformatics knowledge.     

分形凝聚粒子的光散射特性研究

粒子的形状和凝聚对光散射特性有着很大的影响.基于分形生长的受限扩散(DLA)模型,模拟了凝聚粒子的三维空间分形结构,并采用回转半径法计算了凝聚粒子的分形维数.利用离散偶极子近似(DDA)方法研究了纳米石墨凝聚粒子的光散射特性,对于原始粒子数不同的凝聚粒子及分形结构不同的凝聚粒子,数值计算了散射强度和偏振度随散射角的分布...     

半导体粒子CdS的光学性质研究

采用DDA(discrete dipole approximation)方法对用于光催化制氢的半导体粒子的光学性质进行了研究,讨论了形状、尺寸等因素对放置在水中的CdS吸收效率的影响,选取的粒子形状有球形,圆柱形,正四面体,正三棱柱,长方体,正六角棱柱,发现粒子形状对局部表面等离子体共振峰的数目和共振波长有重要影响,而...