电弧

By using a self-made CCD Optical Transient Image System , the vacuum arc images of long gap (40 mm) at various moments are taken photos, and the regular pattern of the vacuum arc mode transition is studied.

应用设计制作的真空电弧图像瞬态摄像系统，对长间隙下（开距40mm不同时刻的真空电弧图像进行了拍摄，获得了真空电弧形态演变过程。

A comparative study of porosity, oxide contents, bond strength and wear resistance of 3Cr13 stainless steel coatings deposited by high velocity and regular arc spray processes was carried out. An orthogonal and rotational regression experimental method and an ordinary single-factor experimental method were adopted to evaluate the coating hardness with respect to the effect of processing parameters. The quantitative formula of processing parameters with coating hardness was obtained by means of microcomputer.

摘 要：对比研究了3Cr13不锈钢高速电弧喷涂涂层和普通电弧喷涂涂层的孔隙率、氧化物含量、涂层结合强度和滑动磨损性能，并采用多因素正交旋转回归设计和单因素对比试验的方法研究了高速电弧喷涂工艺参数对3Cr13不锈钢涂层显微硬度的影响，用微机回归得到了喷涂工艺参数与涂层硬度之间的定量关系式。

A comparative study of porosity, oxide coontents, bond strength and wear resistance of 3Cr13 stainless steel coatings deposited by high velocity and regular arc spray processes was carried out. An orthogonal and rotational regression experimental method and an ordinary single-factor experimental method were adopted to evaluate the coating hardness with respect to the effect of processing parameters. The quantitative formula of processing patameters with coating hardness was obtained by means of microcomputer.The results show that, compared with the regular arc spray process, a dense?

对比研究了3Cr13不锈钢高速电弧喷涂涂层和普通电弧喷涂涂层的孔隙率、氧化物含量、涂层结合强度和滑动磨损性能，并采用多因素正交旋转回归设计和单因素对比试验的方法研究了高速电弧喷涂工艺参数对3Cr13不锈钢涂层显微硬度的影响，用微机回归得到了喷涂工艺参数与涂层硬度之间的定量关系式。

Coating with lower porosity, higher bond strength and hhigher oxide?contents were produced by a newly developed high velocity arc wire spray process.The bond strength in higher than 40MPa, which is increased by 52 percent than that of regular arc sprayed coatings.

结果表明，和普通电弧喷涂涂层相比，高速电弧喷涂涂层组织致密、孔隙率低、涂层氧化物含量增多，涂层-基体界面结合强度大于40MPa，比普通电弧喷涂提高了52％。

The device comprises an arc discharge vacuum chamber; wherein, the arc discharge vacuum chamber is connected with a vacuum pump and is internally provided with a graphite cathode and a graphite anode which are connected with a DC supply. The device is characterized in that the graphite cathode and the graphite anode are respectively provided with an upper spherical crown shape graphite plate and a lower spherical crown shape graphite plate which are matched with each other and formed a spherical crown shape capacitor.

它包括电弧放电真空室，电弧放电真空室与真空泵相连接，电弧放电真空室内设有石墨阴极和石墨阳极，石墨阴极和石墨阳极与直流电源相连接，其特征在于在石墨阴极和石墨阳极上分别设相配合的上球冠形石墨板和下球冠形石墨板，上球冠形石墨板和下球冠形石墨板形成球冠型电容器。

This is because that the addition of arc voltage means the decreasement, so the enlargement of are swing makes the incensement of weld width.

这是因为电弧电压增加意味着电弧的长度增加，因此电弧摆动范围扩大而导致焊缝宽度增加。

In order to make clear the phenomenon of current zero in the arc-quenching chamber of deion plates, the process of dielectric recovery and reignition of short arc between iron plates is investigated, and then the dielectric recovery strengths of various chambers are measured and compared. The different characteristics near current zero in the deion plate chambers are also analyzed based on experiments in the paper.

为弄清栅片灭弧室内电弧电流的过零过程，专门研究了不同条件下栅片间低压短弧的介质强度恢复过程和电弧重燃过程，然后测量了多纵缝和栅片灭弧室的介质恢复强度，对比了它们的熄弧性能，在试验的基础上，分析了栅片灭弧室中电弧电流的过零特征。

At last, arc reignition characteristic is defined for multiple-narrow slot chamber, and the mechanism of arc reignition process is analyzed. A mathematical model which forecasts the arc reignition process is improved for the first time by combining the striking theory of cathode layer with"black box"model for forecasting arc thermal reignition.

最后，通过试验确定了多纵缝陶土灭弧室中电弧重燃特性，对其机理进行了研究，并首次将阴极层击穿理论和预测电弧热重燃的黑盒模型相结合，建立了模拟陶土灭弧室中弧隙由电击穿到热重燃过程的电弧数学模型。

On the base of practical transformer substation main connection, electric components and system circuit model are first formed in the paper; analyze vacuum arc characteristic and medium resume are analyzed, then, according to vacuum chamber physical process of switching AC arc, resume process are divided into three stages: sheath development, neutral particles diffusion and static characteristic, with that, calculating model of medium resume strength is erected and applied in the computing of vacuum circuit breaker interrupting transform overvoltage; In the paper, Saber software is used to simulate a whole switching process; As follows, overvoltage characteristic of vacuum circuit breaker switching no load and load transformers, kinds of influence factors are analyzed in detail; At last, vacuum circuit breaker switching capacitance group overvoltage formative causes and electrode refining for lessening reignition are discuss.

本文针对中低压变电站的实际主接线建立各电气元件及系统的电路模型；在真空电弧的特点及间隙的介质恢复特性上，依据真空断路器灭弧室分断电弧的物理过程，将真空电弧熄灭后的恢复过程分为鞘层发展、中性粒子扩散和静态特性三个阶段，建立了相应的介质恢复强度的计算模型，应用到切除变压器操作过电压的计算中；采用Saber仿真软件模拟计算真空断路器切除变压器操作过电压；并分别对真空断路器切除空载及负载变压器操作过电压的特点与影响操作过电压的各种因素做了详细的分析；最后简要分析了真空断路器开断电容器组过电压的形成原因及为减少重燃的电极老炼措施。

On the base of practical transformer substation main connection,electriccomponents and system circuit model are first formed in the paper;analyze vacuum arccharacteristic and medium resume are analyzed,then,according to vacuum chamberphysical process of switching AC arc,resume process are divided into three stages:sheathdevelopment,neutral particles diffusion and static characteristic,with that,calculatingmodel of medium resume strength is erected and applied in the computing of vacuumcircuit breaker interrupting transform overvoltage;In the paper,Saber software is used tosimulate a whole switching process;As follows,overvoltage characteristic of vacuumcircuit breaker switching no load and load transformers,kinds of influence factors areanalyzed in detail;At last,vacuum circuit breaker switching capacitance groupovervoltage formative causes and electrode refining for lessening reignition are discuss.

本文针对中低压变电站的实际主接线建立各电气元件及系统的电路模型；在真空电弧的特点及间隙的介质恢复特性上，依据真空断路器灭弧室分断电弧的物理过程，将真空电弧熄灭后的恢复过程分为鞘层发展、中性粒子扩散和静态特性三个阶段，建立了相应的介质恢复强度的计算模型，应用到切除变压器作过电压的计算中；采用Saber仿真软件模拟计算真空断路器切除变压器作过电压；并分别对真空断路器切除空载及负载变压器作过电压的特点与影响作过电压的各种因素做了详细的分析；最后简要分析了真空断路器开断电容器组过电压的形成原因及为减少重燃的电极老炼措施。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。