机载机电系统自动测试平台的设计与实现

以提高某型飞机机载机电系统UMS的外场故障定位和隔离能力为背景,实现资源整合,对UMS系统通用自动测试平台GPATE的硬件结构与软件技术进行了研究,介绍了GPATE平台的硬件结构的组成和软件架构的设计,在GPATE平台上采用标准化、模块化设计,实现了硬件的通用性和软件的可移植性。通过实验室静态仿真和外场动态验证表明,GPATE的设计合理、各项指标均能满足实现对UMS系统功能测试的要求,有效地提高了产品的故障检测率。     

MCM-41分子筛负载钼钴系催化剂的程序升温硫化研究

采用程序升温硫化（TPS）技术，研究了负载于MCM－41分子筛的钼钴系催化剂的性能，根据TPOS结果可知，（1）载体和MoO3相互作用的强度顺序如下：Al2O3＞Al2O3-MCM-41＞MCM－41＞TiO2－MCM－41，说明TiO2具有削弱MCM－41和MoO3作用的能力；而Al2O3则相反，它增加了MoO3和MCM－41的相互作用。（2）助剂CoO对负载于未经改性的MCM－41载体上的MoO3的硫化没有明显的促进作用，这和以Al2O3为载体的情况下不同，在Al2O3上，MoO3和CoO可能生成Co-Mo－O复合相，从而促进了MoO3的硫化。（3）助剂CoO对负载于经TiO2和Al2O3改性的MCM－41上的MoO3的硫化起了促进作用。     

Developing a mailed phantom to implement a local QA program in Egypt radiotherapy centers

In this work, a simple method that differs from the IAEA/WHO Thermoluminescent dosimeters (TLD) postal quality assurance (QA) program is developed. A small perspex; polymethyl methacrylate (PMMA), phantom measured 50?mm?×?50?mm?×?50?mm is constructed to be used for absorbed dose verification of high-energy photon beams in some major radiotherapy centers in Egypt. The phantom weighted only 140.7?g with two buildup covers weighted 14.8 and 43.19?g for the Cobalt-60 and the 6-MV X-ray beams, respectively. This phantom is aimed for use in the future’s external audit/QA services in Egypt for the first time. TLD-700 chips are used for testing and investigating a convenient and national dosimetry QA program. Although the used methodology is comparable to previously introduced but new system; it has smaller size, less weight, and different more available material. Comparison with the previous similar designs is introduced. Theoretical calculations were done by the commercial Eclipse treatment planning system, implementing the pencil beam convolution algorithm to verify the accuracy of the experimental calculation of the dose conversion factor of water to the perspex phantom. The new constructed small phantom and methodology was applied in 10 participating radiotherapy centers. The absorbed dose was verified under the reference conditions for both ⁶⁰Co and 6-MV high-energy photon beams. The checked beams were within the 5% limit except for four photon beams. There was an agreement of 0.2% between our experimental data and those previously published confirming the validity of the applied method in verifying radiotherapy absorbed dose.     

A numerical method for one‐dimensional nonlinear Sine‐Gordon equation using collocation and radial basis functions

In this article, we propose a numerical scheme to solve the one‐dimensional undamped Sine‐Gordon equation using collocation points and approximating the solution using Thin Plate Splines (TPS) radial basis function (RBF). The scheme works in a similar fashion as finite difference methods. The results of numerical experiments are presented and are compared with analytical solutions to confirm the good accuracy of the presented scheme.© 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008     

Numerical solution of the nonlinear Klein–Gordon equation using radial basis functions

The nonlinear Klein–Gordon equation is used to model many nonlinear phenomena. In this paper, we propose a numerical scheme to solve the one-dimensional nonlinear Klein–Gordon equation with quadratic and cubic nonlinearity. Our scheme uses the collocation points and approximates the solution using Thin Plate Splines (TPS) radial basis functions (RBF). The implementation of the method is simple as finite difference methods. The results of numerical experiments are presented, and are compared with analytical solutions to confirm the good accuracy of the presented scheme.     

Sustainability assessments of bio-based polymers

Bio-based polymers have become feasible alternatives to traditional petroleum-based plastics. However, the factors that influence the sustainability of bio-based polymers are often unclear. This paper reviews published life cycle assessments (LCAs) and commonly used LCA databases that quantify the environmental sustainability of bio-based polymers and summarizes the range of findings reported within the literature. LCA is discussed as a means for quantifying environmental impacts for a product from its cradle, or raw materials extraction, to the grave, or end of life. The results of LCAs from existing databases as well as peer-reviewed literature allow for the comparison of environmental impacts. This review compares standard database results for three bio-based polymers, polylactic acid (PLA), polyhydroxyalkanoate (PHA), and thermoplastic starch (TPS) with five common petroleum derived polymers. The literature showed that biopolymers, coming out of a relatively new industry, exhibit similar impacts compared to petroleum-based plastics. The studies reviewed herein focused mainly on global warming potential (GWP) and fossil resource depletion while largely ignoring other environmental impacts, some of which result in environmental tradeoffs. The studies reviewed also varied greatly in the scope of their assessment. Studies that included the end of life (EOL) reported much higher GWP results than those that limited the scope to resin or granule production. Including EOL in the LCA provides more comprehensive results for biopolymers, but simultaneously introduces greater amounts of uncertainty and variability. Little life-cycle data is available on the impacts of different manners of disposal, thus it will be critical for future sustainability assessments of biopolymers to include accurate end of life impacts.     

高精度舰艇航向姿态信息标校方法和测量模型研究

提出了一种基于全站仪(TPS)的高精度航向与姿态信息的标校方法和测量模型。通过对模型误差传递的理论分析,证明该模型的精度足以满足对INS等高精度导航设备动态标校的要求。试验结果验证了这一结论。     

Studying the potential of point detectors in time-resolved dose verification of dynamic radiotherapy

Modern megavoltage x-ray radiotherapy with high spatial and temporal dose gradients puts high demands on the entire delivery system, including not just the linear accelerator and the multi-leaf collimator, but also algorithms used for optimization and dose calculations, and detectors used for quality assurance and dose verification. In this context, traceable in-phantom dosimetry using a well-characterized point detector is often an important supplement to 2D-based quality assurance methods based on radiochromic film or detector arrays. In this study, an in-house developed dosimetry system based on fiber-coupled plastic scintillator detectors was evaluated and compared with a Farmer-type ionization chamber and a small-volume ionization chamber. An important feature of scintillator detectors is that the sensitive volume of the detector can easily be scaled, and five scintillator detectors of different scintillator length were thus employed to quantify volume averaging effects by direct measurement. The dosimetric evaluation comprised several complex-shape static fields as well as simplified dynamic deliveries using RapidArc, a volumetric-modulated arc therapy modality often used at the participating clinic. The static field experiments showed that the smallest scintillator detectors were in the best agreement with dose calculations, while needing the smallest volume averaging corrections. Concerning total dose measured during RapidArc, all detectors agreed with dose calculations within 1.1 ± 0.7% when positioned in regions of high homogenous dose. Larger differences were observed for high dose gradient and organ at risk locations, were differences between measured and calculated dose were as large as 8.0 ± 5.5%. The smallest differences were generally seen for the small-volume ionization chamber and the smallest scintillators. The time-resolved RapidArc dose profiles revealed volume-dependent discrepancies between scintillator and ionization chamber response, which confirmed that correction factors for ionization chambers in high temporal and spatial dose gradients are dominated by the volume averaging effect. The unique scaling of the scintillator volumes indicated how such time-dependent volume averaging corrections could be quantified. The time-resolved measurements further supported the claim that small-volume water equivalent detectors are most likely to accurately detect changes in dose delivery, although exact positioning of detectors remains critical.     

光纤接口模块自动测试系统的研究与应用

雷达系统内部含有多种带有光纤接口的数字电路模块,对于这类电路板的测试问题,文中提出了一种构建自动测试系统的通用方法。基于CPCI总线的多功能光纤测试模块作为该测试系统的核心测试部件,对外提供10个可收发的光纤接口,光纤接口数据传输速率可在一定范围内设定,以匹配被测模块的光口速率要求,协议数据包可按用户自定义方式发送和录取,解决了被测模块的多光口测试,光口数据传输速率不统一,数据包格式各不相同的等问题。整个测试过程可由软件控制自动完成。该测试系统能够实现对标准总线和非标准总线的光纤接口雷达数字模块的自动测试,经过实际测试验证表明,该系统运行稳定可靠,提高了武器装备的综合保障能力。     

热塑性淀粉的制备、性质及应用研究进展

淀粉由于可降解、来源广泛、价格低廉、可再生而被认为是最具发展前景的生物降解材料之一,因此,热塑性淀粉材料的研究与开发备受关注。本文综述了近年来热塑性淀粉材料的研究进展情况,内容主要涉及了热塑性淀粉的制备、性质和应用。