浅谈抗干扰技术在生产中的应用

通过分析工业生产中干扰的原因，找出了几种可行的解决办法，使测控系统工作可靠、安全，保证产品质量。     

A Sensitive Electrochemical Impedance Spectroscopy Method for Detection of Polyimide Degradation by Microorganisms

An electrochemical impedance spectroscopy (EIS) technique was evaluated for monitoring microbial degradation of electronic packaging polyimides. The microbial inoculum was a mixed culture of fungi isolated previously from deteriorated polyimides. The active fungal consortium comprised Aspergillus versicolor, Cladosporium cladosporioides, and a Chaetomium species. After inoculation, fungal growth on the polyimides resulted in distinctive EIS spectra indicative of polymer insulation failure, which directly related to polymer integrity. Degradation appeared to occur in a number of steps and two distinctive stages in the decline of film resistance were observed in the inoculated EIS cells within the 2 and 10 weeks after inoculation. The early stage of resistance decrease may be related to the ingress of water molecules and ionic species into the polymeric materials, whereas the second stage probably resulted from partial degradation of the polymers by fungal growth on the polymer film. The relationship between changes of impedance spectra and microbial degradation of the polymer was further supported by scanning electron microscopy (SEM) observations of fungi growing on the surface of the inoculated polyimides. Our data indicate that the EIS can be used in detection of early degradation of resistant polymers and polyimides that are susceptible to biodeterioration.     

绝缘结构综合应力加速寿命试验方法研究

针对绝缘结构在实际使用过程中受到综合应力因素的影响的特点,提出了一种基于综合应力的绝缘结构可靠性评估方法,可以有效地指导绝缘结构加速寿命试验的设计和实施。首先通过对绝缘结构进行失效机理及应力分析,确定影响绝缘结构寿命的主要应力,选取适当的综合应力加速模型。其次,确定各加速应力水平,进行综合应力加速寿命试验方案的设计。最后,基于失效数据对绝缘结构进行可靠性评估。     

船舶海水管路直流杂散电流仿真研究

目的 针对某型船海水管路杂散电流腐蚀穿孔问题,研究海水管路直流杂散电流密度与直流电气设备机壳绝缘电阻关系,评估海水管路直流杂散电流腐蚀风险,提出直流电气设备机壳绝缘电阻要求,为船舶海水管路杂散电流控制提供技术支撑.方法 根据欧姆定律和腐蚀电化学原理,建立船体与海水管路直流杂散电流腐蚀仿真方法,模拟海水管路直管、弯管以及某船海水管路系统结构,以B10铜镍合金极化曲线为边界条件,开展管壁直流杂散电流密度仿真研究,并根据法拉第定律计算直流杂散电流腐蚀速率.结果 直流电气设备接地产生的直流杂散电流大部分流入船体,仅有少部分流入海水管路,正常情况下,机壳绝缘电阻大于1 M?,直流电气设备接地不会导致海水管路发生杂散电流腐蚀.结论 为避免直流电气设备接地造成海水管路杂散电流腐蚀,DC380 V和DC220 V电气设备机壳绝缘电阻应分别不小于211?和123?.     

慢摇吧低音炮传递结构噪声控制研究

对于慢摇吧低音炮传递的结构噪声,采用新型隔声材料静馨隔声毡,结合岩棉等传统吸声材料,可克服传统吸隔声材料的低频吸隔声效果差和"吻合效应"等弱点,从而有效控制音炮传递的结构噪声。     

热防护系统热真空模拟试验技术

介绍了一种能模拟可重复使用运载器热防护系统内、外表面气动热和压力环境的热真空模拟试验装置,该装置不仅能模拟TPS外表面所受气动热和气动压力条件,还能模拟TPS内表面的真空压力环境。其外部环境压力4．0×10^2-2.0×10^5Pa,内部环境压力4．0～1．013×10^5Pa,热面温度可高达1100℃。利用该装置可以对热防护系统的传热性能进行稳态和瞬态测试。简要介绍了该装置的构成及功能,以及用其进行材料和结构的传热性能测试的试验方法。该装置的研制将为我国高超音速飞行器热防护系统的验证提供必要的技术手段。     

Emissions corridors for reducing the risk of a collapse of the Atlantic thermohaline circulation

In this paper, we present the integrated assessment model dimrise (dynamic integrated model of regular climate change impacts and singular events). This model is designed to investigate the stability of the Atlantic thermohaline circulation (THC) and to derive related climate policy recommendations. It is written in GAMS and comprises a dynamic model of the THC coupled to a climate model and a global economy model for assessing the monetary cost of climate protection. The THC model is a dynamic four-box interhemispheric extension of the classic Stommel model calibrated against results obtained using the CLIMBER-2 climate model. The reduced-form climate model used to drive the THC model is the ICLIPS multi-gas climate model, which is a computationally efficient, globally aggregated model able to mimic the response of more sophisticated carbon cycle and atmosphere-ocean general circulation models. The THC and climate modules are coupled to a globally aggregated Ramsey-type optimal growth model of the world economy derived from the Nordhaus DICE model. Together, these components create a novel dynamic fully coupled computationally efficient integrated assessment model. Illustrative applications demonstrate that dimrise is able to derive (constrained) economically optimal emissions paths that comply with prescribed bounds on admissible THC weakening imposed in order to avoid an irrevocable breakdown. In addition, emissions corridors are presented which contain all possible emissions paths that do not endanger the stability of the THC and that simultaneously obey restrictions on welfare loss arising from mitigation efforts. The presented results show that, under worst-case conditions, the stability of the THC may be threatened within two decades if global emissions would not deviate from the business-as-usual trajectory.

离心风机辐射噪声的降噪量预测

本文运用LMS Testlab软件对某风机现场工作时的噪声进行了测试分析,得出风机工作时的噪声频谱特征;运用LMS TestLab Sound Diagnosis模块的声诊断技术对采集到的风机实时信号进行了降噪量预测,为后期的噪声治理提供依据。避免了噪声治理的盲目性,更经济合理。     

吸声无防布的发展趋势与市场分析

吸声无纺布是一种轻型吸声材料,广泛应用于各种噪声控制和室内声学装修场合。本文综述了吸声无纺布的发展概况与趋势,并对其市场、应用前景进行了详细的分析。     

高速铁路声屏障对居民环境影响的试验研究

以三种结构的高速铁路声屏障为研究对象,测量了高速列车通过有声、无声屏障两种状态下8个测点的声压值,并计算各测点等效连续A计权声压和声屏障的隔声量,结合GB3096-2008中规定的环境噪声限值进行声屏障结构对高速铁路周边居民的声环境影响评价。试验分析结果表明:声屏障不同程度改善了居民的声环境;由于试验所用的三种结构的声屏障隔声量离一般设计要求(20~25dB(A))相差太远,使得高速铁路周边环境噪声高于国家标准规定限值;声屏障结构改进应着力提高中低频噪声的隔声量。