FRP透波窗性能设计研究

本研究针对FRP透波窗在使用频段范围实现透波率和结构性能的需求，通过材料选择、透波性能设计、仿真分析和结构设计，采用夹层结构形式，制造了FRP透波窗试验件，进行了结构试验和透波试验。试验结果表明，FRP透波窗的结构设计满足承载和密封性要求，同时在1.0GHz～3.0GHz频段范围内的透波率均大于80%,满足透波性要求。实现了对FRP透波窗的承载、密封和透波的设计要求，可以对内部设备的运行状态实现监测。     

树脂基透波复合材料研究进展

综述了树脂基透波复合材料的研究进展，在提出透波复合材料要求的基础上，对常用树脂基体和增强纤维的特点进行了介绍。分析了界面对透波复合材料性能的影响规律，提出了今后我国在树脂基透波复合材料方面的研究方向。     

透波复合材料的研究进展

介绍了我国通用透波复合材料、特种透波复合材料、隐身透波复合材料的性能水平,概括地总结了我国雷达罩用功能透波复合材料的研究进展,并对今后的发展方向进行了预测。     

复合材料透波罩头部电性能优化设计

透波罩是导弹等飞行器的重要组成部分,其电性能好坏直接影响导弹的制导精度和作用距离。本文针对球锥这一典型外形的透波罩,对球头区域进行仿真优化设计。建立球锥透波罩几何模型,确定关键尺寸参数,并根据复合材料的相关电性能参数和入射角分布情况,对透波罩进行初始半波壁壁厚设计;基于FEKO仿真平台,采用矩量法(MOM)结合多层快速多级子(MLFMM)算法对模型进行仿真计算,获得透波罩在俯仰向不同扫描角状态下的透波率随端头厚度的变化规律;基于电性能变化规律,对球锥透波罩头部进行优化设计。分析球头电性能的变化规律,为后续透波罩头部设计提出了优化方向,提供了技术支撑,对透波罩的设计具有一定的借鉴与指导意义。     

纤维增强树脂基复合材料透波板的研制和试验

本文介绍了一种新型的天线窗用纤维增强树脂基复合材料透波板的研制过程,并对研制的透波板在透波率、抗高低温能力、抗震动冲击能力和承载能力等几方面进行了试验验证。结果表明,新研制的透波板具有良好的透波性能和力学性能。     

树脂基电磁透波复合材料研究进展

介绍了电磁透波复合材料性能的具体要求；综述了国内外聚酰亚胺、聚四氟乙烯、氰酸酯和有机硅树脂等树脂基透波复合材料的特性和研究现状，并对其应用前景及关键技术进行了展望。     

高温透波陶瓷材料研究进展

透波陶瓷材料已成为高超声速飞行器天线罩、天线窗等部件的关键候选材料。因此,如何有效提升透波陶瓷材料的耐温、透波、承载等特性是发展高超声速飞行器的关键技术之一。本文针对高超声速飞行器对透波陶瓷材料的技术要求,阐述了透波陶瓷材料的发展历史,着重对现有透波陶瓷材料体系及其透波特性测试方法和原理的研究历史和现状进行了全面回顾,并提出今后的发展方向。本文旨在为未来新一代高超声速飞行器的设计提供参考。     

航天透波复合材料的研究进展

介绍了对舷天透波材料的具体要求，并详细探讨了航天透波复合材料纤维增强材料和树脂基体的研究进展，最后简单介绍了湿度、树脂含量、孔隙率、吸水性、后处理温度及时间、纤维的表面处理等因素对复合材料透波性能的影响。     

微波加热用透波材料的研究进展

微波加热技术因其绿色环保、体积加热、选择性加热等优势,已被广泛应用于化工强化、金属冶炼、陶瓷烧结、食品加工等众多领域,但微波在反应器内普遍存在透波效果差、微波利用率低等问题。随着微波加热技术的不断发展,微波加热设备中透波材料的选用越来越受到大家的关注。本文主要针对透波材料在微波加热领域中的应用现状进行综述,对透波材料的种类进行简要介绍,分别从微波加热用容器和保温材料两方面进行论述。详细介绍了氧化物、氮化物、硅酸盐、磷酸盐等高温透波材料及聚四氟乙烯、玻纤增强树脂基、环氧树脂等中、低温透波材料的研究进展,并具体论述了目前微波加热常用纤维棉、纤维毯和纤维板等各种陶瓷纤维制品的介电特性和透波性能,最后指出了目前微波加热用透波材料普遍存在的问题,并对透波材料的应用和发展作出了展望。     

二氧化硅体系透波材料的透波机理及研究现状

本文阐述了天线罩材料对二氧化硅体系透波材料的性能要求,分析了二氧化硅体系透波材料的透波机理,论述了二氧化硅体系透波材料的研究现状,并指出了其发展方向.     

天然气输差问题的分析与研究

输差是控制输气成本的一个最关键的指标,如何降低输差是管输企业面临的难题。针对输气系统的输差问题,从误差理论出发,以输气干线系统为研究对象,分析了产生输差问题的原因,对标准孔板引起的测量误差、输气干线测量误差和测量误差造成的输差进行了计算,给出了单点输差和综合输差的计算方法,并提出了降低输差的措施和方法。     

Measurement of Lateral Transmission of Force in the Extensor Digitorum Longus Muscle of Young and Old Mice

The main function of skeletal muscles is to generate force. The force developed by myofiber contraction is transmitted to the tendon. There are two pathways of force transmission from myofibers to tendons: longitudinal transmission that depends on tension elicited via the myotendinous junction and lateral transmission that depends on shear elicited via the interface between the myofiber surface and surrounding connective tissue. Experiments using animal muscle and mathematical models indicated that lateral transmission is the dominant pathway in muscle force transmission. Studies using rat muscle showed that the efficiency of lateral force transmission declines with age. Here, the lateral transmission of force was measured using the extensor digitorum longus muscle from young and old mice. Dependence on longitudinal transmission increased in the old muscle, and there was a trend for lower efficiency of lateral force transmission in the old muscle compared to the young muscle. There was a noticeable increase in the connective tissue volume in the old muscle; however, there was no significant change in the expression of dystrophin, a critical molecule for the link between the myofiber cytoskeleton and extracellular matrix. This study demonstrates the measurement of lateral force transmission in mouse muscles and that alteration in force transmission property may underlie age-related muscle weakness.     

提高天然气管道输送效率方法的探讨

从天然气长输管道系统组成、特点入手,分析了影响天然气管道输送效率的因素,提出了提高天然气管道输送效率的措施。     

A Closed-form Solution for the Torque Transmission Capability of the Adhesively Bonded Tubular Double Lap Joint

The adhesively bonded tubular double lap joint has better torque transmission capability and reliability in bonding than the single lap joint.

In this paper, an analytic solution for the torque transmission capability and stress distribution of the adhesively bonded tubular double lap joint was derived assuming linear properties of the adhesive.

From the analytic solution, it was found that the torque transmission capability of the double lap joint was more than 40% larger than that of the single lap joint.     

工程陶瓷材料的声透射特性研究

针对工程陶瓷材料对声波的传播过程中声透射系数问题,从波动方程入手,利用传递矩阵法及声波气-固边界条件建立了声波在工程陶瓷材料的声透射系数特性数学模型,研究了垂直入射条件下不同频率声波在工程陶瓷材料中的声透射系数规律.仿真结果表明,当工程陶瓷材料的厚度为半波长整数倍时,此时声透射系数最大;当声波的频厚积是陶瓷厚度与其声速乘积一半的整数倍时,此时声透射系数最大.为工程陶瓷材料的隔声性能分析及声学检测提供了一定的理论基础.     

推进剂火焰烟尘对CARS测温精确度的影响

采用透过率(激光透过率、可见光透过率)表征推进剂火焰烟尘的量,以理论计算温度作为CARS(Coherent Anti-Stokes Raman Spectrometry)测温的相对标准温度,并将测得的CARS温度与热电偶温度进行了对比。通过研究CARS温度和理论计算温度的差值与透过率的相关性得到烟尘对CARS测温的影响规律：CARS测温的偏差随着推进剂火焰中烟尘量的增加而增大;推进剂火焰烟尘对CARS测温精度的影响规律基本呈线性关系。     

Development of a Fatigue Failure Model for the Adhesively Bonded Tubular Single Lap Joint under Dynamic Torsional Loading

The adhesively bonded tubular single lap joint shows nonlinear torque transmission capability and deformation characteristics under static torsional loading because of nonlinear properties of the adhesive. However, the dynamic or fatigue torque transmission capability can be calculated with linear, analysis because the stress-strain relation under torsional fatigue loading is linear, due to the small dynamic transmission capability compared with the static torque transmission capability.

In this paper, a failure model for the adhesively bonded tubular single lap joint under torsional fatigue loading was developed with respect to the adhesive thickness, which is the critical factor for the static torque transmission capability. Also, a design method for the adhesively bonded tubular single lap joint under torsional fatigue loading was proposed.     

织物防紫外线性能与测试方法的研究

使用辐射强度计和紫外分光光度计分别测定了各种织物的紫外线透过率,发现两种测试方法具有很好的相关性。织物的覆盖系数对紫外线透过率影响特别显著,并呈负相关关系;而容重对织物抗紫外线性能影响不大。合理选用功能性抗紫外线纤维可以更好地获得抗紫外线性能。     

Development of a Fatigue Failure Model for the Adhesively Bonded Tubular Single Lap Joint under Dynamic Torsional Loading

The adhesively bonded tubular single lap joint shows nonlinear torque transmission capability and deformation characteristics under static torsional loading because of nonlinear properties of the adhesive. However, the dynamic or fatigue torque transmission capability can be calculated with linear, analysis because the stress-strain relation under torsional fatigue loading is linear, due to the small dynamic transmission capability compared with the static torque transmission capability.

In this paper, a failure model for the adhesively bonded tubular single lap joint under torsional fatigue loading was developed with respect to the adhesive thickness, which is the critical factor for the static torque transmission capability. Also, a design method for the adhesively bonded tubular single lap joint under torsional fatigue loading was proposed.     

Measuring the extent of exfoliation in polymer/clay nanocomposites using real-time process monitoring methods

Dielectric and optical transmission measurements obtained during processing of polymer/clay composites yielded quantitative information about the extent of clay exfoliation in the polymer matrix. Measurements were made using an instrumented slit die that was situated at the exit of a twin screw extruder. Nylon 6, 11 and 12 resins were compounded with several organo modified montmorillonite clays. Dielectric and optical data were correlated with off-line transmission electron microscopy. Dielectric observations revealed a large Maxwell-Wagner (MW) relaxation whose characteristic frequency reflects an RC time constant associated with the conduction of ions and the polarization of the resin/clay interface. Optical transmission measurements showed that transmission increased with increasing extent of exfoliation because light scattering due to aggregate clay particles is reduced as the particles exfoliate nanosize silicate flakes. Extent of exfoliation models, based on MW relaxation time and its relationship to interfacial polarization, and based on optical transmission measurements, are developed.