An automated food protein isolation approach on preparative scale by two‐dimensional liquid chromatography with active modulation interface

In this work, an automated 2D‐LC approach for protein isolation from egg samples on preparative scale is proposed. The method is based on the use of a C18 guard column installed in a switching valve to focus the proteins coming from the first dimension column, before their elution in the second column. For the first dimension separation, a size‐exclusion column, packed with 3 μm ultrapure silica particles was used. An RP column based on core‐shell technology was used for the second dimension separation. A standard mixture of BSA, β‐lactoglobulin, and glucose oxidase, chosen as a protein model system, was used to optimize the chromatographic separation conditions. The fully automated workflow allowed to isolate, in a single‐chromatographic analysis, a protein amount of 50 μg for each peak fraction, with a total time of 15 min for the first separation and additional 30 min of the second separation for each trapped protein. The final aim was the development of proper analytical tools for protein isolation from foodstuffs to be used for the molecular identification by MS, as well as for biotherapeutic uses, allergy testing, and large‐scale investigations in biological systems.     

Physics of particulate flows: From sand avalanche to active suspensions in plants

Flows of granular media in air or in a liquid have been a research field for physicists for several decades. Sometimes solid, sometimes liquid, these particulate materials exhibit peculiar behaviors, which have motivated many studies at the frontiers between nonlinear physics, soft matter physics and fluid mechanics. This paper presents a summary of the recent advances in the field, with a focus on the development of continuous approaches, which make it possible to treat granular media as a complex fluid and to develop a granular hydrodynamics. We also discuss how the better understanding of granular flows we have today may help to address more complex materials, such as colloidal suspensions or some biological systems.     

Likert-scale questionnaires as an educational tool in teaching discrete mathematics

In this paper, we report on the results of an experiment in teaching discrete mathematics to students majoring in business informatics. We supplemented our problem-based approach to teaching the course with a set of Likert-scale surveys or questionnaires that helped improve the students’ performance. On the one hand, these surveys gave us feedback and, on the other, encouraged the students to reflect on the subject-matter. The experiment was quite successful, as the grades obtained by the students on the exam were significantly higher than usual. Here, we describe the structure of the surveys and the method of evaluation of the experimental results.     

大型随动圆顶自抗扰控制方法研究

针对大型随动圆顶具有大转动惯量,且存在非线性摩擦的特点,根据自抗扰控制原理,设计圆顶随动系统控制器,提高系统的动态性能。介绍了圆顶随动系统的构成及简化模型;以及基于自抗扰控制器的圆顶随动系统设计方案,并给出了控制器参数整定方法。最后,进行了Simulink仿真和实验验证。实验结果表明,相对于传统的PID控制器,自抗扰控制器既可以保证系统在无超调的情况下快速响应,又能够抑制摩擦和死区等非线性因素对系统跟踪性能的影响,可以有效提高圆顶随动系统的动态性能。     

Windows 2003活动目录实现校园网信息化管理

随着基于Windows Server2003目录服务应用日益流行,各类组织可以开始使用Active Directory管理各种复杂的企业网络环境．该文进一步探讨TNgd该技术对校园网内部联网的资源进行统一、安全、灵活的设计、控制和管理实现,     

打印技术制备表面增强拉曼散射活性基底的研究进展

表面增强拉曼散射(SERS)是一种先进的表面分析技术,可以极大提高吸附在金属表面或附近分子的拉曼散射信号。SERS技术由于其快速准确、灵敏度高、选择性好、样品制备要求低等特点,成为当前的研究热点,在化学、食品、生物、医疗等领域展现出重要的应用前景。而利用SERS技术作为一种常规分析和诊断工具面临的一个主要挑战是如何制备均匀、可重复、稳定的活性基底。打印技术操作简单、效率高、成本低,有助于设计等离激元纳米结构。通过优化“热点”增强电磁场,获得重复性好、稳定性高、增强能力强的SERS活性基底。近年来,印刷技术逐渐被应用于SERS基底的制备。主要综述了制备SERS基底的几种常用印刷技术,包括喷墨印刷、凹版印刷、丝网印刷等。分析了衬底表面润湿性、干燥温度、油墨粘度、表面张力、溶剂等因素对SERS性能的影响。总结了印刷技术制备SERS基底的研究进展,并对其潜在应用和未来发展作了展望。     

活泼氢的核磁共振氢谱

核磁共振氢谱是有机化合物结构表征中最常使用的波谱方法之一,提供了有机化合物质子的化学位移、积分面积和耦合裂分等信息。常见的活泼氢是与氧、氮和硫共价相连的氢原子,存在着快速交换机制,与碳上的氢有显著的差异。在不同条件下活泼氢化学位移不固定、峰形多变并且耦合裂分情况复杂。本文探讨了如何通过核磁共振氢谱解析活泼氢,培养学生对谱图进行观察、分析以及结构推导的能力。     

Integrated design of piezoelectric damping system for flexible structure

This paper aims at developing an integrated design method of the active/passive hybrid type of piezoelectric damping system for reducing the dynamic response of the flexible structures due to external dynamic loads. The design method is based on the numerical optimization technique whose objective function is a control effort of the active damping. A vibration suppression performance, which is evaluated by the maximum value of the gain of the frequency response function of the structure, is constrained. In order to demonstrate the structural damping capability of the hybrid type of piezoelectric damping system designed by proposed method, numerical simulation and laboratory experiment will be done using a three-story flexible structure model equipped with 12 surface bonded PZT tiles pairs. Both numerical and experimental results indicate that the optimally designed hybrid piezoelectric damping system can be successfully achieving excellent performance as compared to a conventional purely active piezoelectric damping system.     

Optical display of true 3D objects in depth-priority integral imaging using an active sensor

In this paper, we propose a system combining the pickup process using an active sensor and the display process using depth-priority integral imaging (DPII) system to display true three-dimensional (3D) objects within large depth through real and virtual image fields. The active sensor provides depth map and color images of 3D objects. Using captured depth map and original color images, elemental images are computationally synthesized and displayed optically in DPII system. Proposed system provides scaling of 3D scenes for true 3D object. To show the usefulness of proposed system, we carry out the experiment for true 3D objects of three character patterns and present the experimental results.     

浅析网络计算模式的演变与发展

本文在介绍网络计算模式概念的基础上，回顾了网络计算模式的演变历程，并分析了网络计算模式的发展动向。