Mass overload in preparative liquid chromatography: Choice of column dimensions and optimum working conditions

Summary This paper deals with a theoretical study which makes it possible to calculate column dimensions (length and inner diameter) and to select working conditions (particle diameter of the column packing, elution flow rate, run number) with regard to purity, recovery ratio and amount of pure substance that is to be isolated. These determinations take into account the pressure limitation and pumping capacity of the available chromatograph.     

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.     

Optimization-Based Available-To-Promise with Multi-Stage Resource Availability

Increasingly, customer service, rapid response to customer requirements, and flexibility to handle uncertainties in both demand and supply are becoming strategic differentiators in the marketplace. Organizations that want to achieve these benchmarks require sophisticated approaches to conduct order promising and fulfillment, especially in today’s high-mix low-volume production environment. Motivated by these challenges, the Available-to-Promise (ATP) function has migrated from a set of availability records in a Master Production Schedule (MPS) toward an advanced real-time decision support system to enhance decision responsiveness and quality in Assembly To Order (ATO) or Configuration To Order (CTO) environments. Advanced ATP models and systems must directly link customer orders with various forms of available resources, including both material and production capacity. In this paper, we describe a set of enhancements carried out to adapt previously published mixed-integer-programming (MIP) models to the specific requirements posed by an electronic product supply chain within Toshiba Corporation. This model can provide individual order delivery quantities and due dates, together with production schedules, for a batch of customer orders that arrive within a predefined batching interval. The model considers multi-resource availability including manufacturing orders, production capability and production capacity. In addition, the model also takes into account a variety of realistic order promising issues such as order splitting, model decomposition and resource expediting and de-expediting. We conclude this paper with comparison of our model execution results vs. actual historical performance of systems currently in place.     

硫掺杂碳纳米球的制备、表征及其储氢性能——化学材料相关专业综合设计性实验教学的探索与实践

综合设计性实验是培养大学生综合素质和创新能力最重要的途径之一。根据化学与材料相关专业的特点,开设"硫掺杂碳纳米球的制备、表征及其储氢性能"综合设计性实验项目,通过文献调研、原理阐述、方案制定、材料制备、结构表征、性能测试、数据处理与分析等实验环节,使学生充分掌握与化学和材料相关的多门课程内涉及的纳米材料制备、结构表征、性能分析等关键知识点,培养学生的综合能力和创新能力。实践表明,通过综合设计性实验的实践,学生的实践能力、创新能力、基本科学素养和综合素质得到明显提高。     

中学体育教师的教学能力结构及其模糊综合评价

本文根据信息论、系统论的观点,运用教育学、心理学和管理学的知识,采用调查法,专家法等方法对体育教师的教学能力结构进行了研究,确定了由四个部分二十二个指标 构成的体育教师教学能力结构。在此基础上,采用“改进的对偶比较法”确定各个指 标的权重,再运用模糊教学方法建立了中学体育教师教学能力的二级模糊综合评价模型.并 用该模型对43 名实习生进行实际考察,还将该模型编制成 B ISI C 程序     

REMOVAL OF MERCURY FROM WATER USING POLYPYRROLE AND ITS COMPOSITES

One of the suitable methods for removing heavy metals from water is by using surface adsorption process. In this paper, the preparation of polypyrrole and its composites as adsorbents are discussed and the capability of separating mercury from water is investigated. The results indicated that the polypyrrole and its composites are able to remove mercury from aqueous media. Furthermore the adsorption percentage is related to the surface morphology, type of additives and its concentration.     

卟啉钴分子筛的制备,表征和催化性能的研究

用液－固相分步合成法将新型四卤四甲基卟啉诱捕在经Ｃｏ＾２＋交换的ＮａＸ分子筛超笼内，利用索式提取器洗净分子筛外表面吸附的卟啉后，采用ＵＶ－Ｖｉｓ、ＩＲ、ＳＥＭ、ＤＴＡ、Ｘ射线衍射分析、吸附等手段对诱捕在超笼内的卟啉予以表征。进一步对比研究了卟啉、分子筛和诱捕卟啉分子筛的催化性能。结果表明，卟啉与分子筛结合后，催化活性大大提高。     

以“理-工-医”交叉融合实现源头创新——生物医学工程交叉学科研究生培养实践探索

针对科学技术和国家社会发展对生物医学创新型人才的需求，依托于学校的重大项目培育和新兴交叉学科研究课题，建立了生物医学工程与化学、物理、材料、电子和医学等"理-工-医"多学科交叉科研平台。基于"以人为本""全面发展"等现代教育理念和"以学生发展为中心"的高等教育思想，通过组建跨学科的研究生导师团，多导师联合指导，夯实学生多学科基础知识，加强学生对知识的理解和使用，拓宽研究生知识广度，着力培养研究生源头创新能力，打造研究生解决多学科交叉重要问题的能力。实践表明，多学科交叉科研平台在激发研究生源头创新思维、拓展专业知识、培养工程实践能力等方面起到重要的作用。对继续完善多学科交叉的研究生培养体系建设给出了建议。     

Tutorial on estimating the limit of detection using LC-MS analysis,part I: Theoretical review

A large body of literature exists on the limit of detection (LOD), but there is still a lot of confusion about this important validation parameter. This confusion mainly stems from its statistically complex background. The goal of this two-part tutorial is to discuss and clarify the topic of LOD for practitioners. The two main conclusions of this tutorial are: (1) the choice of how to estimate LOD should be based on the purpose of the analytical method that is being validated (e.g. considerable effort should not be made to estimate LOD for a method that is not used for detecting traces in the vicinity of LOD), and (2) LOD estimates are strongly dependent on different assumptions and the approach used, and therefore caution must be exercised when using the estimate or when comparing different estimates.     

Robust design space development for HPLC analysis of five chemical components in Panax notoginseng saponins

The present work describes the systematic development of a robust, precise, and rapid reversed-phase liquid chromatography method for the simultaneous analysis of five chemical components in Panax notoginseng saponins (PNS) using quality by design (QbD). The method was developed in two main phases: screening and optimization. During the screening phase, the most suitable stationary phase, column temperature, and flow rate were identified, while the secondary influential parameters, such as the gradient slope, the initial concentration of acetonitrile, and the initial isocratic hold of the gradient elution system were fine-tuned in the later optimization phase. In this phase, a 17-run experiment was used to examine multifactorial effects of these parameters on the critical resolution, analysis time, and peak symmetry. The Monte Carlo simulation method was successfully used to build the chromatographic design space and the process capability index C_p was introduced to evaluate the robustness of the design space. At last, the verification experiment was performed within the working design space by the accuracy profile methodology and model was found to be accurate. A robust combination of separation conditions predicted in the design space was obtained with the gradient slope of 1.6% · min^?1, the initial concentration of acetonitrile of 20%, and the initial isocratic hold of 20 min, and the total analysis time was no more than 40 min. The results demonstrated that rapid separation of five components of PNS herbal extract could be achieved on the chromatographic column packed with narrow size particles at backpressures available in ordinary high performance liquid chromatography (HPLC) instruments.