常压N2+H2O气液DBD等离子体处理PP无纺布的超亲水性研究北大核心CSCD

采用接触式气液介质阻挡放电装置,采用常压N2和N2+去离子水(H2O)两种介质阻挡放电等离子体对PP无纺布的表面进行改性研究,实验结果表明PP无纺布经N2+H2O等离子体处理60 s后表面出现了超亲水,其表面水接触角降为0°。但是经N2等离子体处理60 s,表面接触角由未处理时的115.8°降低至62°,并未出现超亲水。通过扫描电镜、X射线光电子能谱的对比分析发现,PP经N2+H2O等离子体处理60 s后,表面出现粘连、刻蚀,表面C1s的含量由原来的96.7%下降到31.8%,同时表面O1s和N1s的含量分别增加到38.4%和29.8%,比PP经N2等离子体处理60 s后C1s多降低20.8%,而O1s和N1s的含量分别多增加了12.7%和8.1%,并且PP表面分子出现明显的交联;而FTIR-ATR的结果进一步表明,PP经N2+H2O等离子体处理60 s后表面接入更多的-OH,从而导致表面超亲水。     

Spectroscopic study of bipolar nanosecond pulse gas-liquid discharge in atmospheric argon

Atmospheric gas-liquid discharge with argon as a working gas is presented by employed nanosecond pulse power. The discharge is presented in a glow-like mode. The discharge powers are determined to be less than 1 W, and remains almost constant when the discharge duration time increases. Bountiful active species are determined by capturing optical emission spectra,and their main generation processes are also discussed. The plasma gas temperature is calculated as 350 K by comparing the experimental spectra and the simulated ones of N_2(C~3Ⅱ_g→B~3Ⅱ_g, Δv =-2). The time resolved vibrational and rotational temperature is researched to present the stability of discharge when pulse voltage and discharge duration vary.The electron density is determined to be 10~(16) cm~(-3) according to the Stark broadening effect of the H_α line.     

国外润滑油倾点稳定性的研究

本文介绍了国外润滑油倾点稳定性的研究结果,指出加有降凝剂的润滑油的倾点稳定性和基础油的粘度、精制深度、精制方法有关,并和润滑油—蜡—降凝剂平衡体系中蜡的性质和数量有关。     

Generation of atmospheric pressure air diffuse discharge plasma in oxygen enriched working gas with floating electrode

In this work, a floating electrode is employed to generate a stable large-area diffuse discharge plasma under an open oxygen-rich environment. The discharge image and the optical emission spectra of the N₂(C-B),N₂⁺(B-X), N²(B-A), and O(3p–3s, 777 nm) are measured to analyze the morphological and optical characteristics of the discharge. The effects of applied voltage, gas flow rate, and electrode gap on the reactive species, vibrational temperature and...     

Comparative research of plasma-assisted milling and traditional milling in synthesizing AlN

In this paper, traditional milling and discharge plasma-assisted milling are employed to synthesize aluminum nitride (AlN) powder at nanometer scale by milling the mixture of aluminum and lithium hydroxide monohydrate. AlN powders can be generated in traditional milling and plasma-assisted milling in an hour milling time. Differential thermal analysis curves show that the reaction temperature of the powders treated by plasma-assisted milling is lower than that of traditional milling. These results indicate that plasma-assisted milling has higher efficiency in the synthesis of AlN, getting smaller crystallite size and activating powder. Moreover, an optical emission spectrum is employed to demonstrate the active species in plasma. The different formation process of AlN in the two-milling process, and the promotion effects of plasma in the milling process are discussed.     

充水系统在除鳞中的应用

在钢铁热连轧生产线精轧高压水除鳞系统中,除鳞水由高压离心式除鳞泵加压后,高压水通过喷射阀及除鳞充水系统后进入除鳞集管进行除鳞作业;不除鳞时,喷射阀关闭,高压水通过除鳞充水系统后由除鳞集管的喷嘴排出。整个高压水除鳞系统由充水系统代替最小流量系统对泵的保护,保证在不除鳞时,除鳞泵有流量输出,能有效防止除鳞泵发热、汽蚀及机械故障。     

高压离心泵在除鳞系统的调速控制分析

热轧板带生产线的除鳞系统采用变频器调速的运行方式来降低能耗。结合实际生产情况,提出根据轧线上钢坯位置信号,对除鳞泵采用恒速与调速的搭配运行方式,此运行方式与蓄能器压力、液位调速模式相结合,能降低蓄能器的压降,保证轧线除鳞所需要的压力,同时可防止系统事故的出现,增加系统的稳定性,也能更好实现能源的有效利用,达到节能减排的作用,还能延长除鳞泵的使用寿命。     

Volume added surface barrier discharge plasma excited by bipolar nanosecond pulse power in atmospheric air: optical emission spectra influenced by gap distance

In this paper, volume barrier discharge with different gap distances is added on the discharge border of high-voltage electrode of annular surface barrier discharge for generating volume added surface barrier discharge (V-SBD) excited by bipolar nanosecond high-voltage pulse power in atmospheric air. The excited V-SBDs consist of surface barrier discharge (d=0 mm) and volume added surface barrier discharges (d=2 mm and 3 mm). The optical emission spectra are recorded for calculating emission intensities of N₂ (C ³Ⅱ_u →B³Π_g ) and N₂⁺ (B ²Σ_u⁺ → X ²Σ_g⁺ ), and simulating rotational and vibrational temperatures. The influences of gap distance of V-SBD on emission intensity and plasma temperature are also investigated and analyzed. The results show that d=0 mm structure can excite the largest emission intensity of N ₂ (C ³ Π_u →B ³Π_g ), while the existence of volume barrier discharge can delay the occurrence of the peak value of the emission intensity ratio of N₂⁺ (B ²Σ_u⁺ → X ²Σ_g⁺ )/N ₂(C³Π_u →B³Π_g ) during the rising period of the applied voltage pulse and weaken it during the end period. The increasing factor of emission intensity is effected by the pulse repetition rate. The d=3 mm structure has the highest threshold voltage while it can maintain more emission intensity of N₂(C³ Π _u →B ³Π_g ) than that of d=2 mm structure. The structure of d=2 mm can maintain more increasing factor than that of the d=3 mm structure with varying pulse repetition rate. Besides, the rotational temperatures of three V-SBD structures are slightly affected when the gap distance and pulse repetition rate vary. The vibrational temperatures have decaying tendencies of all three structures with the increasing pulse repetition rate.     

润滑油基础油对降凝效果的影响

一、引言添加剂工作者向重视降凝剂的生产工艺的改进与完善。就我们所知,石油七厂、北京石油科学研究院等,从50年代起至今曾作了许多研究工作。实践逐渐使我们深入思索一个问题:降凝剂的使用效果好与差并不完全取决于剂本身。曾经听到     

高压水除鳞系统管路预充水方式的选择

热轧生产线配套的高压水除鳞系统设备在除鳞作业间歇时对除鳞阀后管路进行预充水,能有效防止管路失水变成空管而集气,消除除鳞作业时引起管路冲击、振动,防止管路设备的损坏,其预填充水方式有低压充水和高压充水两种。非节能型除鳞泵和蓄能器混合供水的除鳞系统,以及除鳞泵直接供水的除鳞系统宜选择高压充水方式,系统增加的能量很少,安全可靠;节能型除鳞泵和蓄能器混合供水的除鳞系统宜选择低压充水方式,系统能耗低,但系统安全性相对较差。