Comparison of the TSI Model 3306 Impactor Inlet with the Andersen Cascade Impactor: solution metered dose inhalers

The product performance of a series of solution Metered Dose Inhalers (MDIs) were evaluated using the TSI Model 3306 Impactor Inlet and the Andersen Cascade Impactor (ACI). The goal of the study was to test whether the fine particle and coarse particle depositions obtained using the Model 3306 were comparable to those results obtained by ACI testing. The analysis using the Model 3306 was performed as supplied by the manufacturer as well as with 20 cm and 40 cm vertical extensions that were inserted between the Model 3306 and the USP Inlet. Nine different solution formulations were evaluated. The drug concentrations ranged from 0.08 to 0.8% w/w and the ethanol cosolvent concentration varied between 5 and 20% w/w. In general, it was found that good correlations between the two instruments were obtained. However, for formulations containing 10-20% w/w ethanol it is shown that an extension fitted to the Model 3306 yielded an improved correlation to those obtained from the ACI.     

基于OpenGL的小卫星在轨运行仿真系统研究

传统的航天工业仿真技术主要用于分析计算航天器的飞行轨道与姿态运动,这种仿真方式通常不支持三维可视化仿真功能;文章结合卫星轨道、姿态动力学和计算机图形学,设计基于三维实时动态显示技术的小卫星在轨运行仿真系统,对卫星轨道、姿态进行可视化仿真,实时动画演示星内敏感器的工作状态,提供图形曲线和文本形式的分析数据,并能与卫星地面站进行数据通讯,实现小卫星的在轨监测功能;仿真结果表明,仿真系统能正确实时接收地面站的数据,支持二维、三维动画输出,可以成功完成小卫星系统的仿真与监测功能.     

MDI与TDI聚氨酯固化剂用于双组分溶剂型聚氨酯涂料的变色对比

以不同2,4'体含量MDI合成的聚氨酯固化剂与TDI合成的聚氨酯固化剂进行变色情况对比,结果表明,50%2,4'体含量MDI合成的固化剂与TDI-80合成的固化剂变色相当,采用自制的80%2,4'体含量MDI合成的聚氨酯固化剂变色程度比TDI-80合成的聚氨酯固化剂好,并对变色原因进行了理论分析和探讨。     

影响MDI型聚氨酯预聚体合成和性质的因素

介绍了二苯基甲烷二异氰酸酯(MDI)型聚氨酯预聚体的特点,探讨了影响MDI型聚氨酯预聚体的合成、贮存稳定性、黄变的因素。     

实验室帐务管理系统的设计与应用

介绍了LAMS（实验室帐务管理系统）的设计与应用，对系统开发中的几个问题进行了探讨，并附以必要的程序代码。     

MDI地震属性技术在东濮凹陷HZJ地区储层预测中的应用

简要介绍了MDI地震属性技术在进行储层预测时的研究思路，对HZJ地区井信息和三个砂层组地震属性信息进行了提取和优选．进行了砂岩厚度和含油气性的预测，同时对预测的不确定性和风险进行了分析。     

IPTV服务质量关键技术研究

IPTV服务质量直接影响用户的体验,是IPTV得以运营的关键技术之一。目前国内外致力于提高服务质量的技术研究,尚未形成标准。本文结合QoS和QoE分析IPTV服务质量的关键技术,从区分服务模型、MDI和基于IPv6的频道切换技术的角度提出改进IPTV服务质量的方案。     

Supporting multi-user real-time VBR video service using dynamic bandwidth management based on prediction

Real-time variable bit rate (VBR) video is expected to take a significant portion of multimedia applications. However, plentiful challenges to VBR video service provision have been raised for its characteristic of high traffic abruptness. To support multi-user real-time VBR video transmission with high bandwidth utilization and satisfied quality of service (QoS), this article proposes a practical dynamic bandwidth management scheme. This scheme forecasts future media rate of VBR video by employing time-domain adaptive linear predictor and using media delivery index (MDI) as both QoS measurement and complementary management reference. In addition, to support multi-user application, an adjustment priorities classified strategy is also put forward. Finally, a test-bed based on this management scheme is established. The experimental results demonstrate that the scheme proposed in this article is efficient with bandwidth utilization increased by 20%-60% compared to a fixed service rate and QoS guaranteed.     

IPTV频道切换技术研究

本文在分析IPTV直播业务体系的基础上,深入研究频道切换的原理和流程,从频道切换时间、QDI的影响和用户行为模式等方面分析IPTV频道切换性能的关键制约因素,提出提高频道切换性能的建议。     

MDC分解法制备MDI的研究进展

综述了MDC（二苯基甲烷二氨基甲酸甲酯）分解法制备MDI（二苯基甲烷二异氰酸酯）的机理、分类、反应条件及国内外有关研究进展;以烷类或酯类作溶剂,锌或锌的氧化物作催化剂的工艺会逐渐成熟;开发性能优良、价格便宜、工业应用前景良好的催化剂体系,实现装置的连续化生产和采用恰当的反应工艺以利于实际工业生产是未来的研究方向。