辣椒碱表面活性剂泡囊处方设计

目的 研究辣椒碱表面活性剂泡囊的处方设计.方法 采用注入法制备辣椒碱表面活性剂泡囊,以包封率为评价指标,评价不同组成材料制备的辣椒碱表面活性剂泡囊.结果 得到9种辣椒碱表面活性剂泡囊处方,其平均包封率均≥75%,粒径分布为5～30 μm,平均粒径均≤10 μm.结论 本文筛选得到9种包封率较高、粒径大小理想的辣椒碱表面活性剂泡囊处方,为进一步的研究奠定了基础.     

Study on the Design,Preparation, and Performance Evaluation of Heat-Resistant Interlayer-Polyimide-Resin-Based Neutron-Shielding Materials

Polymers have an excellent effect in terms of moderating fast neutrons with rich hydrogen and carbon, which plays an indispensable role in shielding devices. As the shielding of neutrons is typically accompanied by the generation of γ-rays, shielding materials are developed from monomers to multi-component composites, multi-layer structures, and even complex structures. In this paper, based on the typical multilayer structure, the integrated design of the shield component structure and the preparation and performance evaluation of the materials is carried out based on the design sample of the heat-resistant lightweight polymer-based interlayer. Through calculation, the component structure of the polymer-based materials and the three-layer thickness of the shield are obtained. The mass fraction of boron carbide accounts for 11% of the polymer-based material. Since the polymer-based material is the weak link of heat resistance of the multilayer shield, in terms of material selection and modification, the B₄C/TiO₂/polyimide molded plate was prepared by the hot-pressing method, and characterization analysis was conducted for its structure and properties. The results show that the ball milling method can mix the materials well and realize the uniform dispersion of B₄C and TiO₂ in the polyimide matrices. Boron carbide particles are evenly distributed in the material. Except for Ti, the other elemental content of the selected areas for mapping is in good agreement with the theoretical values of the elemental content of the system. The prepared B₄C/TiO₂/polyimide molded plate presents excellent thermal properties, and its glass transition temperature and initial thermal decomposition temperature are as high as 363.6 °C and 572.8 °C, respectively. In addition, the molded plate has good toughness performs well in compression resistance, shock resistance, and thermal aging resistance, which allows it to be used for a long time under 300 °C. Finally, the prepared materials are tested experimentally on an americium beryllium neutron source. The experimental results match the simulation results well.     

Optimization-Based Economical Flexural Design of Singly Reinforced Concrete Beams: A Parametric Study

In the past, many studies have been conducted on the optimization of reinforced concrete (RC) structures. These studies have demonstrated the effectiveness of different optimization techniques to obtain an economical design. However, the use of optimization techniques to an obtain economical design is not so practical due to the difficulty in applying most of the optimization techniques to achieve an optimal solution. The RC beam is one of the most common structural elements encountered by a practising design engineer. The current study is designed to highlight the potential of the Solver tool in MS Excel as an easy-to-use option for optimizing the design of simply supported RC beams. A user-friendly interface was developed in a spreadsheet in which beam design parameters from a typical design can be entered and an economical design can be obtained using the Evolutionary Algorithm available in the MS Excel Solver tool. To demonstrate the effectiveness of the developed optimization tool, three examples obtained from the literature have been optimized. The results showed that up to 24% economical solution can be obtained by keeping the same material strengths that were assumed in the original design. However, if material strength is also considered as a variable, up to 44% of the economical solution can be obtained. A parametric study was also conducted to investigate the effect of different design variables on the economical design of simply supported RC beams and to derive useful rules of thumb for their design and proportioning, with the objective of cost minimization. The results of the parametric study suggest that the grade of the reinforcing steel is one of the most influential factors that affect the cost of simply supported RC beams. Practicing engineers can use the trends derived from this research to further refine their optimal designs.     

维生素D3—β—环糊精包合物的制备及鉴定

探讨优化维生素Ｄ３－β－环糊精包合物的制备方法并鉴定其形成。方法：以维生素Ｄ３利用率和收率为综合指标研究了溶液法、胶体磨法、超声波法和研磨法等制备维生素Ｄ３－β－环糊精包合物的方法。结果：当β－环糊精和维生素Ｄ３以３：１摩尔量投料时维生素Ｄ３利用率和收率最高。     

基于WORD2003电子病历数据的追溯统计方法与程序设计

论述了基于WORD2003文件形式存储的电子病历数据追溯与统计的程序设计,通过对WORD2003文件的遍历和读取,实现数据元的匹配,并实现患者与科室文件名称、文件路径和数据元统计信息的对应,便于实现数据信息的追溯。此程序的设计实现,操作较灵活,可以针对WORD2003任意路径、多数据元同时统计,并按格式显示和输出,便于使用者对基于WORD形成的历史病历数据实现二次整理和分析。     

网络环境下教师指导性活动的设计

网络教学为学生的学习提供了丰富的资源，拓延了教学时空的维度，对现有的教学内容、教学手段和教学方法提出了挑战。本文探讨了在此环境下教师指导活动的内容，设计原则及其设计方法等问题。     

数字化口腔种植外科导板的精确度研究

目的 本研究通过分析种植体术前设计和术后的三维位置,来评估数字化口腔种植导板的精确度.方法 根据修复体的生物学功能和美学要求,使用3D种植软件对种植体位置进行设计.将设计的种植导板转化为手术用种植导板,指导47颗种植体植入合适位置.通过重叠术前和术后的CT扫描图像,分析植体肩部和根部的线性误差以及植体长轴的角度误差,比...     

Beyond information access: Support for complex cognitive activities in public health informatics tools

Public health professionals work with a variety of information sources to carry out their everyday activities. In recent years, interactive computational tools have become deeply embedded in such activities. Unlike the early days of computational tool use, the potential of tools nowadays is not limited to simply providing access to information; rather, they can act as powerful mediators of human-information discourse, enabling rich interaction with public health information. If public health informatics tools are designed and used properly, they can facilitate, enhance, and support the performance of complex cognitive activities that are essential to public health informatics, such as problem solving, forecasting, sense-making, and planning. However, the effective design and evaluation of public health informatics tools requires an understanding of the cognitive and perceptual issues pertaining to how humans work and think with information to perform such activities. This paper draws on research that has examined some of the relevant issues, including interaction design, complex cognition, and visual representations, to offer some human-centered design and evaluation considerations for public health informatics tools.     

On revenue maximization for selling multiple independently distributed items

Consider the revenue-maximizing problem in which a single seller wants to sell k different items to a single buyer, who has independently distributed values for the items with additive valuation. The case was completely resolved by Myerson’s classical work in 1981, whereas for larger k the problem has been the subject of much research efforts ever since. Recently, Hart and Nisan analyzed two simple mechanisms: selling the items separately, or selling them as a single bundle. They showed that selling separately guarantees at least a fraction of the optimal revenue; and for identically distributed items, bundling yields at least a fraction of the optimal revenue. In this paper, we prove that selling separately guarantees at least fraction of the optimal revenue, whereas for identically distributed items, bundling yields at least a constant fraction of the optimal revenue. These bounds are tight (up to a constant factor), settling the open questions raised by Hart and Nisan. The results are valid for arbitrary probability distributions without restrictions. Our results also have implications on other interesting issues, such as monotonicity and randomization of selling mechanisms.