新氢压缩机填料密封故障分析及改进

介绍新氢压缩机填料密封的结构与原理。针对该型压缩机密封填料使用寿命短、密封效果不佳的状况,分析填料密封失效的主要原因,得出影响压缩机填料密封寿命的主要因素,在不改变填料盒结构的前提下,从密封组件的结构设计和材料选用等几个方面对密封填料提出具体的改进措施。     

基于参数估计的光纤水听器解调系统研究

研究并实现了可工程应用的光纤水听器解调系统,采用相除查找表的PGC解调方案和逐步参数估计的参数提取方法.从理论上详细阐述了参数提取方法原理,并从实验上分析了该方法的稳定性和有效性.实验测试表明1倍频/2倍频相位延迟的提取精度优于5％.光强、伴生调幅和角度修正因子的估算精度分别达到0.5％,2.5％和5％,能够满足实际工程应用要求.所研制的光纤水听器解调系统解调结果谐波分量较少,失真小.相比于标准压电水昕器系统,具有很好的线性度.解调系统噪声本底达到- 90 dB/Hz@ 100 Hz和- 95 dB/Hz@1 kHz.10 h连续测试,SINAD方差小于1 dB,THD方差约为2 dB,表明系统具有较好的稳定性.上述技术指标,达到了目前工程应用要求.     

污染地块土壤气中挥发性卤代烃的检测技术

本文建立了一种新型的土壤地块调查采样方法：受污染地块土壤气中挥发性卤代烃的采样方法,用气相色谱法进行分析。同时论述了土壤气采样技术的注意事项。结果表明5种卤代烃的检出限在0.09～0.40μg/L范围内,回收率在91%～103%之间,相对标准偏差在3.0%～6.3%之间。土壤气采样技术对于调查大范围挥发性有机物污染具有简单易行、高效的特点;并且土壤气所代表的污染区域比土壤要广     

低碳中铬钢渗碳层的耐磨粒磨损性能研究

对低碳中铬钢（1Cr6Si2Mo）固体法稀土渗碳层的组织和耐磨性能与渗碳20钢及淬火Cr12Mo1V钢进行了对比试验研究。1C6Si2Mo钢的渗碳层内含有大量粒度为2．5－3．0μm、弥散分布的铬碳化物,其尺寸比Cr12Mo1V钢中的共晶碳化物小。渗碳淬火后的1Cr6Si2Mo钢试样耐磨粒磨损性能大大优于渗碳淬火后的20钢,但不及真空热处理的Cr12Mo1V。     

INVESTIGATION ON THE VALENCE STATE OF Ce ATOM IN BULK AND NANOCRYSTAL CeO2 BY X-RAY ABSORPTION AND PHOTOEMISSION

1. IntroductionRare earth oxides are potentially useful Inaterials for various optical and electronicapplications such as optical waveguides, optical filters, and capacitors. Nanocrystallinerare earth oxides, RE.Oy, where RE=Ce, Pr, Tb etc. x=1 or 2 and y=2 or 3, are playingan increasingly important role in solid state physics, chemistry, materials science, and evenbiologylll. The ability to synthesis nanocrystals of high quality and to understand themicrostructure properties in the nanocr…     

Vortex mechanism in hydrocyclones

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｓａｗｉｄｅｌｙｕｓｅｄｓｅｐａｒａｔｉｏｎｄｅｖｉｃｅ ,ｈｙｄｒｏｃｙｃｌｏｎｅｉｓｓｉｍｐｌｅｉｎｓｔｒｕｃｔｕｒｅ ,ｂｕｔｒａｔｈｅｒｃｏｍｐｌｅｘｉｎｆｌｏｗｐａｔ ｔｅｒｎ .Ｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｔａｎｇｅｎｔｉａｌｖｅｌｏｃｉｔｙｉｓｃｏｍ ｐｒｉｓｅｄｂｙ ｑｕａｓｉ ｆｒｅｅｖｏｒｔｅｘａｎｄｆｏｒｃｅｄｖｏｒｔｅｘ ,ｔｈｅｃｏｍｐｏｕｎｄｏｆｔａｎｇｅｎｔｉａｌａｎｄａｘｉａｌｆｌｏｗｒｅｓｕｌｔｓｉｎｉｎｎｅｒｖｏｒｔｅｘａｎｄｏｕｔｖｏｒ…     

Radial nanofretting behaviors of ultrathin carbon nitride film on silicon substrate

With a nanoindenter, the radial nanofretting behaviors of amorphous ultrathin carbon nitride (a-CN_x) film on the silicon substrate were investigated by a spherical diamond indenter. The experimental results indicate that the radial nanofretting damage on a-CN_x film usually successively experiences the buckling, cracking and detachment of film. These damages can be easily detected by the variation in the apparent contact stiffness. Generally, the initial increase in the contact stiffness indicates the buckling of film; the following sharp decrease in the contact stiffness reveals the initiation and propagation of circular cracks in film; the final stable contact stiffness implies the detachment of film.     

A repetitive S-band long-pulse relativistic backward-wave oscillator

This paper presents both numerical and experimental studies of a repetitive S-band long-pulse relativistic backward-wave oscillator. The dispersion relation curve of the main slow-wave structure is given by the numerical calculation. Experimental results show that a 1 GW microwaves with pulse duration of about 100 ns (full width of half magnitude) under 10 Hz repetitive operation mode are obtained. The microwave frequency is 3.6 GHz with the dominant mode of TM(01), and power conversion efficiency is about 20%. The single pulse energy is about 100 J. The experimental results are in good agreement with the simulation ones. By analyzing the experimental phenomenon, we obtain the conclusion that the explosive emission on the surface of the electrodynamics structure in intense radio frequency field mainly leads to the earlier unexpected termination of microwave output.     

Design of shared instruments to utilize simulated gravities generated by a large-gradient, high-field superconducting magnet

A high-field superconducting magnet can provide both high-magnetic fields and large-field gradients, which can be used as a special environment for research or practical applications in materials processing, life science studies, physical and chemical reactions, etc. To make full use of a superconducting magnet, shared instruments (the operating platform, sample holders, temperature controller, and observation system) must be prepared as prerequisites. This paper introduces the design of a set of sample holders and a temperature controller in detail with an emphasis on validating the performance of the force and temperature sensors in the high-magnetic field.     

钼炉耙臂装卸夹具的建模与应力分析

在SolidWorks软件平台上建立钼炉耙臂装卸夹具的三维模型,对夹具结构进行设计分析,检验其合理性。同时对所建零件模型进行虚拟装配,然后对装配模型进行三维动态检查。Solid-Works软件的使用提高了夹具的设计效率,也提高了其设计质量。