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In this paper the noise sources of the WUTAISHAN-30 type tract or is analyzed,from which the maximum noise source-the exhaust noise-has been found out.on the basis of the necessary frequency characteristics of sound attenuation by absorption as a design datum for the exhaust muffler of internal combustino engine,The muffler with two-stage expansion chambers and boring plate configuration is designed.Calculating formula of trasmission loss for the multiple-stage expansion muffler is given,and the test result... In this paper the noise sources of the WUTAISHAN-30 type tract or is analyzed,from which the maximum noise source-the exhaust noise-has been found out.on the basis of the necessary frequency characteristics of sound attenuation by absorption as a design datum for the exhaust muffler of internal combustino engine,The muffler with two-stage expansion chambers and boring plate configuration is designed.Calculating formula of trasmission loss for the multiple-stage expansion muffler is given,and the test result indictes that the exhaust noise of the tractor can be effctively controlled by using this muffler. 本文分析了五台山-30拖拉机的噪声源,找出了最大的噪声源——排气噪声。以内燃机排气噪声必需的消声量频率特性作为设计消声器的依据,设计了二级扩张式和穿孔板组合消声器。文中给出了多级扩张式消声器消声量实用的传递损失计算公式。试验结果表明,采用这种消声器后,拖拉机的排气噪声得到了有效控制。 A taxonomic study on 5 species of red tide causative dinoflagellates was conducted. Samples collected from Dapeng Bay (Shenzhen, Guangdong, South China Sea)included 2 species of Prorocentrum: P. micans Ehrenberg, P. minimum (Pavillard)Schiller; 2 species of Alcxandrium: A. tamarense (Lebour) Balech, A. catenella(Whedon and Kofoid) Balech; and 1 species of Scrippsiella: S. trochoidea (Stein)Loeblicli III. The morphological differences (i. e. the cal plate configuration) between the two easily confused species:... A taxonomic study on 5 species of red tide causative dinoflagellates was conducted. Samples collected from Dapeng Bay (Shenzhen, Guangdong, South China Sea)included 2 species of Prorocentrum: P. micans Ehrenberg, P. minimum (Pavillard)Schiller; 2 species of Alcxandrium: A. tamarense (Lebour) Balech, A. catenella(Whedon and Kofoid) Balech; and 1 species of Scrippsiella: S. trochoidea (Stein)Loeblicli III. The morphological differences (i. e. the cal plate configuration) between the two easily confused species: A. tamarensc and A. catenella are discussed.The morphology of germinated resting cysts of Alexandrium and Scripptiella wasalso studied. 对采自深圳大鹏湾的5种赤潮甲藻进行了分类学研究。其中海洋原甲藻属Prorocentrum2种:P.micansEhrenberg,P.minimum(Pavillard)Schiller;亚历山大属Alexandrium2种:A.tamarense(Lebour)Balech,A.cutenella(Whedon&Kofoid)Balech;施克里普藻届Scrippsiella1种:S.trochoidea(Stein)LoeblichIII。 The atmospheric pressure glow discharge (APGD)is a new kind of plasma source that has been recently developed. It has wider industrial application prospects compared with low-pressure glow discharge. A stable, homogeneous glow discharge plasma device produced in our laboratory and controlled by dielectric barrier at 1atm is introduced in detail. It is capable of operating by using 10/20KHz-power supply, a parallel plate configuration with electrodes being covered by insulating surfaces, 2mm of gap distance... The atmospheric pressure glow discharge (APGD)is a new kind of plasma source that has been recently developed. It has wider industrial application prospects compared with low-pressure glow discharge. A stable, homogeneous glow discharge plasma device produced in our laboratory and controlled by dielectric barrier at 1atm is introduced in detail. It is capable of operating by using 10/20KHz-power supply, a parallel plate configuration with electrodes being covered by insulating surfaces, 2mm of gap distance and many kinds of working gases. The measurements of the discharge current pulse shapes and lissajous figure of voltage-electric charges provide sufficient evidence that this is really a uniform glow discharge at atmospheric pressure. 常压辉光放电 (APGD)是新近发展起来的一种等离子体源 ,与低气压辉光放电相比更具有工业应用前景 .本文详细介绍我们实验室在大气压条件下建立的均匀稳定、介质垒控制的辉光放电等离子体发生装置 .该放电发生器采用频率为 1 0 k Hz和 2 0 k Hz高压电源 ,平板电极结构 ,电极覆盖绝缘层 ,间隙2~ 3mm,可在多种气体环境下稳定运行 .放电电流波形和电压 -电荷李萨如图形的测量充分表明它确实是常压下的均匀辉光放电 .
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