低温等离子体表面强化技术研究进展

简要介绍等离子体的相关概念和分类,根据等离子体电极结构、放电特性不同将等离子体分为热等离子体和温和等离子体,并对比两种等离子体表面强化技术的异同点.在此基础上,从当前研究进展和存在的关键科学技术问题两个角度,梳理热等离子体喷涂技术在制备热障涂层、耐磨涂层、梯度功能材料等领域的应用,对温和等离子体表面强化技术(等离子体物理气相沉积、等离子体化学气相沉积以及冷等离子体)在纳米纤维改性、高压绝缘、生物医学等领域的应用进展进行了综述.最后,从等离子体产生技术、表面强化技术应用以及微观-宏观过程控制三个角度分析了等离子体表面强化技术的未来发展方向,对等离子体表面强化技术的多学科发展融合和综合利用提供一定的参考.     

国内等离子体机种子处理技术

等离子体机种子处理技术,是用物理方法对种子进行处理的农业高新技术.1999年大连博事等离子体有限公司研发了等离子体种子处理机,2000年吉林省农科院开始在不同生态区域进行试验,并通过国家"863"项目组验收.此项技术为国内首创,获得国家发明专利.     

等离子体种子处理技术初探

介绍了等离子体种子处理技术的技术原理,通过对比试验,分析了等离子体种子处理技术的优势,得出此项技术是一项实用性强、科技含量高,具有显著经济效益和生态效益的新型物理技术.     

离子束金属材料表面改性技术

本文综述了国内外离子束金属材料表面改性技术的研究概况,叙述了离子镀、离子注入、离子束混合、离子束增强沉积和等离子体浸没离子注入等表面技术的特点和应用.     

利用Hβ谱线斯塔克增宽效应测量壁稳氩弧等离子体电子密度

一、前言等离子体电子密度测量是等离子体诊断的一项重要内容.电子密度是等离子体的重要参数之一,等离子体的许多性质都与它有关.在局部热力学平衡条件下,利用 Saha 方程可以从电子密度求得等离子体温度.在等离子体辐射中,谱线强度、谱线轮廓和连续光谱发射系数等的计算也常常用到电子密度.     

新型等离子体点火技术试验获成功

近日,新型等离子体点火器首次在中国航天科技集团公司六院11所某试验台点火成功,验证了等离子体点火技术在火箭发动机发生器上应用的可行性和重复使用的可靠性。新型等离子体点火器产生的等离子体流具有高温、高焓、化学活性强的优点,并具备多次启动的功能。新型等     

低温等离子体降低生物柴油发动机有害排放的研究

根据介质阻挡放电理论,设计出低温等离子体发生器.利用气相色谱/质谱联用仪对生物柴油样品进行了测定,确定了生物柴油的主要成分.通过台架试验研究了低温等离子体对生物柴油和0号柴油发动机有害排放的作用规律,运用扫描电镜和X射线能谱仪对柴油机排气中收集的颗粒物样品进行检测和分析.研究结果表明:低温等离子体技术可以有效降低柴油机颗粒物排放,NO<,x>排放总量变化较小;生物柴油属于富氧燃料,可使发动机燃烧室碳燃料充分燃烧,颗粒物样品中碳烟成分较少,颗粒粒径也较小.元素分析结果表明,低温等离子体技术受燃料中硫的影响较小,是一项有前途的柴油机排气后处理技术.     

等离子体种子处理对玉米生产影响试验

等离子体种子处理技术是通过模仿太空环境,对种子进行等离子体辐照和交变电磁作用,提高种子的活力.种植试验结果证明玉米平均增产18.37%,在中低产田上应用效果更加明显.     

等离子体改善飞机性能的应用

本文主要叙述了在航空领域中运用的等离子体,介绍了三种重要的机载等离子体发生器,讨论了等离子体在飞机减阻与隐身方面的应用,简要分析了将等离子体应用于改善飞机性能所急需解决的问题,说明等离子体技术在改善飞机性能应用上是可行的,应引起国内研究者的高度重视.     

等离子体种子处理技术研究

冷等离子体种子处理技术是国际上近来发展的农业增产新技术。冷等离子种子处理技术的研究,关键在于冷等离子体处理设备的研制;运用等离子体辉光放电技术产生的电子、离子、激发态活性粒子和紫外光等对农作物种子内能的激活作用,使作物发芽率提高,抗旱、抗病、生长旺盛,从而达到提高产量和改善产品品质的目的。等离子体技术无变异、无污染、成本低,该技术和设备的推广应用将对农业装备现代化产生重大的影响。     

穿孔等离子弧焊接中等离子云电流的产生机制及简化模型

为完善等离子体控制技术,基于等离子体物理理论的知识,对穿孔等离子弧焊接时等离子云产生机理进行了研究,分析探针测量等离子云时产生电流的原因。当把探针放置在等离子云中,由于等离子体的特殊性,将在探针上产生了负电位,通过分析发现,这个负电位大小与检测处等离子体温度有关。从等离子体物理理论的角度出发,将等离子体导电过程简化等效为一个具有内阻的电源,建立了适应于穿孔等离子弧焊接中等离子云电特性的简化模型。该模型能够较好地解释等离子云电信号随着探针到工件中心距离的增加而单调减小的规律,同时给出了探针放置的最佳位置。     

Characteristic of a triple-cathode vacuum arc plasma source

In order to generate a better ion beam, a triple-cathode vacuum arc plasma source has been developed. Three plasma generators in the vacuum arc plasma source are equally located on a circle. Each generator initiated by means of a high-voltage breakdown between the cathode and the anode could be operated separately or simultaneously. The arc plasma expands from the cathode spot region in vacuum. In order to study the behaviors of expanding plasma plume generated in the vacuum arc plasma source, a Langmuir probe array is employed to measure the saturated ion current of the vacuum arc plasma source. The time-dependence profiles of the saturated current density of the triple vacuum arc plasma source operated separately and simultaneously are given. Furthermore, the plasma characteristic of this vacuum arc plasma source is also presented in the paper.     

Note: flowing ion population from a resonance cavity source

The experimental low energy plasma for hemispherical analyzers nominal testing thermal plasma facility of Dartmouth College uses a microwave plasma source which generates an ionosphere-like plasma through a two-step process. The plasma is initially generated inside a cylindrical, insulated, resonance cavity. This initial plasma must pass through a sheath in order to enter the main experimental region. This process imparts a significant flow velocity to the ions which has been neglected in previous analysis of this plasma source. We predict the flow energy of the ions to be between 12-15 eV depending on conservation laws and show agreement with experimental results.     

亚铁嗪法测定血浆铁假性升高的原因及解决办法

目的:探讨亚铁嗪法测定血浆铁假性升高的原因及解决办法。方法:用试管法实验观察反应体系的变化;用血清和血浆两种校准品分别校准生化分析仪,配对测定20例血清和血浆标本。结果:血浆中的纤维蛋白原在测定条件下变性使反应体系产生混浊,从而干扰测定,使结果假性升高,血浆标本结果(169.29±43.80 μ g/dL)与血清标本结果(98.34±47.93 μ g/dL)比较,差异有统计学意义(t=16.14,P<0.001)。血浆定标后测定血浆标本,结果(107.1±37.88 μ g/dL)与对应的血清铁(98.34±47.93 μ g/dL)比较,差异无统计学意义(t=1.994,P>0.05 )。结论:用血浆定标法测定血浆铁可基本消除纤维蛋白原的干扰。     

血浆润滑性能的试验研究

在人工器官的研制和使用过程中,血浆常被作为润滑剂,与人工合成的润滑剂相比,血浆具有一定的优越性。按照GB3142-82方法测试出了血浆的承载能力,采用Leica DMI5000M材料显微镜观察了磨痕的微观特征。研究表明,血浆的润滑性能良好,承载能力可达390N左右,此研究为人工器官的润滑设计提供了依据。分析了血浆润滑膜的组成,指出速度不变的情况下,压力的增大将导致血浆润滑膜的破裂,使钢球磨损加剧。     

低温等离子体处理柴油机有害排放的比较研究

分析了低温等离子体转化柴油机排气中有害成分的反应机理,设计了三种不同结构类型的低温等离子体反应器,并进行了基于发动机台架的实验研究。研究结果表明,低温等离子体对柴油机排气中的颗粒物及NO有较好的转化作用,采用全流式低温等离子反应器,延长排气在反应器中的滞留时间,有利于提高能量利用率及排气中颗粒物、NO的分解转化率。     

等离子体原子发射光谱检测器在气相色谱中的应用进展

综述了气相色谱-原子发射光谱检测器(GC-AED)的常用几种等离子体形式及在石油化工、化学战剂，高聚物，农残、环境等领域中的应用进展，并对GC—AED的发展及应用提出了看法。     

等离子喷涂在先进材料研究与开发中的应用(二)──等离子制粉、植入与辅助沉积薄膜

等离子喷涂由于具有高洁净气氛、高热焓、高反应速度、高冷却速度、原位快速团结成形及中间环节少等特点，在先进材料研究与开发及现代成形制造技术中的应用越来越多。该文综述了等离子喷涂技术在等离子喷涂涂层、等离子近净成形、等离子合成高附加值材料、等离子制备超细微粉、等离子植入和等离子辅助沉积薄膜等方面特别是在等离子喷涂FGMs和等离子辅助沉积金刚石薄膜中的应用。     

Development of a Concept of Reflectometric Diagnostics for the ITER Tokamak for Plasma Probing from the High-Magnetic-Field Side

The capabilities of the reflectometric diagnostics in the ITER facility during plasma probing from the high-magnetic-field side are investigated. This technique allows measurements of the density profile and the plasma turbulence-rotation velocity at the lower extraordinary wave from a plasma with a critical density to the center of the plasma column. The system also allows one to probe the plasma column at the ordinary wave. It is proposed to use a combined mirror–horn antenna system. Under conditions where there is limited space for placing horns, this results in a significant (up to 20 dB) increase in the signal, compared to the system of two horns considered earlier. The results of calculations on optimizing the elements of the waveguide transmission line using a two-dimensional full-wave code are presented. The possibility of employing the Doppler effect to study plasma rotation by using antennas for controlling the shape of the plasma column while performing reflectometry at the lower extraordinary wave is considered. This effect is estimated theoretically in the actual ITER plasma configuration.     

Plasma cell adaptation to enhance particle acceleration

A plasma study is performed in order to construct a cell for plasma acceleration purpose. As well, a multicell design is introduced for the injection of beam driver application. The suggested idea is experimentally demonstrated for two plasma cell configuration. The preformed plasma is obtained by a symmetrically driven capacitive audio frequency discharge. It is featured by its moderate pressure of 0.1-0.2 Torr, low consumption power of 130 W maximum, low discharge voltage and frequency up to 950 V and 20 kHz, respectively, and high plasma density from 10(11) to 10(15) cm(-3). The electron temperature obtained by Langmuir double probe varies from 1 up to 16 eV. It is observed that the increases of the discharge voltage and frequency enlarge the plasma parameters to their maximum values. The plasma cell filled with different gases demonstrates that the Ar and He gases manifest the highest ionization efficiency exceeding 100% at 950 V and 20 kHz. The formed plasma is cold; its density is uniform and stable along the positive column for long competitive lifetime. Showing that it follows the conditions to enhance particle acceleration and in conjunction with its periphery devices form a plasma cell that could be extended to serve this purpose. Demonstrating that an injected electron beam into the extended preformed plasma could follow, to long distance, a continuous trajectory of uniform density. Such plasma generated by H(2) or Ar gases is suggested to be used, respectively, for low-density or higher density beam driver.