Deposition of Diamond-Like Carbon on Inner Surface by Hollow Cathode Discharge

A cylindrical hollow cathode discharge （HCD） in CH4/Ar gas mixture at pressure of 20-30 Pa was used to deposit diamond-like carbon （DLC） films on the inner surface of a stainless steel tube. The characteristics of the HCD including the voltage-current curves, the plasma im- ages and the optical emission spectrum （OES） were measured in Ar and CHn/Ar mixtures. The properties of DLC films prepared under different conditions were analyzed by means of Raman spectroscopy and scanning electron microscopy （SEM）. The results show that the electron exci- tation temperature of HCD plasma is about 2400 K. DLC films can be deposited on the inner surface of tubes. The ratio of sp3/sp2 bonds decreases with the applied voltage and the deposition time. The optimizing CH4 content was found to be around CH4/Ar =1/5 for good quality of DLC films in the present system.

Degradation of Alizarin Red by Hybrid Gas-Liquid Dielectric Barrier Discharge

A system based on dielectric barrier discharge （DBD） with improved discharge sta- bility and homogeneity was used for the degradation of Alizarin Red （AR）. This special structure of the DBD system is characterized by the high voltage electrode, which is covered with a quartz tube and partially immersed in water, and by directly using the water as the ground electrode. A transition was realized from the filamentary mode for the conventional structure of the DBD to the semi-homogeneous mode for such a configuration of the plasma discharge. The spectra of plasma are dominated by N2 molecular lines in the ultraviolet-A radiation region. Plasma degra- dation of AR in this system exhibited pseudo-first-order reaction kinetics. The degradation rate of AR reached 95% or so after 14 min treatment under favorable conditions. Alkaline conditions are favorable for the degradation of AR. The increase of conductivity of the solution, input power and usage of oxygen bubbling could enhance AR degradation.

Pulsed Corona Discharges and Their Applications in Toxic VOCs Abatement

plasma processes are among the emerging technologies for volatile organic compounds (VOCs) sbatoment. Both thermal plasmas and non-equil[brimn plasmas (cold plasmas) are being developed for VOCs clesnup. Particularly, pulsed corona discharges offer several edvantages over conventional VOCs abatement tochniqvee, To optimize the existing technology and to developit further, there is need to understand the mechanlsms involved in plasma chemical reacticms, Furthermore, it is strongly desirable to be able to predict the behavior of new VOCs in non-equillbrlum plasma enviromuent from the data known for a few representative oompounds, Pulsed corona discharge technique is introduced here with dtafion of refevant literature, Fundamental principfes,useful for predicting the VOCs' decomposition behavior, have been worked out from the published literature. Latest developments in the area, targeted to minimize the enersy losses, improve the VOCs destruction efficiency and reduce the generation of unwanted organic and inorganic by-products, are presented.

Numerical Modelling and Simulation of Chemical Reactions in a Nano-Pulse Discharged Bubble for Water Treatment

A zero-dimensional model to simulate a nano-pulse-discharged bubble in water was developed. The model consists of gas and liquid phases corresponding to the inside and outside of the bubble, respectively. The diffusions of chemical species from the gas to the liquid phase through the bubble interface was also investigated. The initial gas is Ar, but includes a little H20 and 02 in the bubble. The time evolution of the OH concentration in the liquid phase was mainly investigated as an important species for water treatment. It was shown that OH was generated in the bubble and then diffused into the liquid. With the application of a continuous nano-pulse discharge, more OH radicals were generated as the frequency increased at a low voltage for a given power consumption.

流凌封河预报指标法及其在黄河内蒙古河段的应用

把流凌封河累积负气温作为黄河内蒙古河段封河预报关键指标,明确累积负气温与封河流量、降温强度、河槽形态等的关系,确定现有河槽形态以及海勃湾水库运用影响下不同流量和降温强度封河所需的累积负气温,并建立了流凌封河累积负气温预估公式。指标法可以在很大程度上提高黄河内蒙古河段封河预报的预见期与精度。

无线通信技术在二水厂沉淀池自动控制系统中的应用

本文主要阐述无线通信技术在净水厂排泥系统中的应用。在水厂生产过程中,应用无线AP技术,通过PLC自动控制,能够有效解决人工排泥效率差的问题。无线AP技术能够在雷雨、高温等恶劣的露天环境中为沉淀池自动控制系统提供稳定可靠的数据通信,保障水厂生产的正常连续运行。实际应用表明,该系统运行效果良好,既降低排泥用水消耗,减少人工工作量,又降低人身安全风险,为净水厂排泥系统提供了一种较好的选择方案。

基于人工智能优化的等离子体空气净化系统

致病微生物气溶胶(PMA)是典型的环境污染物,也是对人类健康的主要威胁之一。为了解决传统的高效颗粒空气过滤器(HEPA)系统只能过滤PMA的主要局限性,该研究开发了一种新的等离子体空气净化系统(PAPS),它可以同时过滤PMA并杀死内部的微生物。本系统采用大面积的针状电晕放电阵列覆盖气流通道,并设计了专有的模块化组件,使得PAPS组件易于清洁和重复使用,以实现长期、低成本的运行。此外,该研究集成了人工神经网络与遗传算法(ANN-GA)来优化PAPS的工作参数。通过在最佳工艺条件下对PMA进行有效捕捉和灭活,验证了ANN-GA模型的可靠性。本研究通过层流场、电场、等离子体场和带电粒子运动的多物理场耦合模拟,研究了PAPS系统的净化机制,并进一步验证了其关键工作参数。最终的实验证明,在最佳工作参数下,PAPS可以有效地拦截和灭活PMA中的所有细菌。

空气净化器净化过滤组件的可靠性技术研究

空气净化器作为常见的家用电器,可以有效消除室内细菌、甲醛和PM_(2.5)颗粒等物质,因而广受青睐。通过净化过滤组件打火放电导致空气净化器在线测试过程中出现噪声的案例,文章将通过试验研究火花放电的机理和板间距合理性、异物对空气净化器过滤组件的影响,并提出可靠的改善方案。

氮氧化物税率优化及其经济影响——基于大气自净能力视角

氮氧化物税率高低对相关产业的生产积极性和生态环境保护成果具有重要影响,大气具备的自我修复和净化能力可以减轻企业的减排压力和税负,为量化大气自净能力并构建一个相关动态税率优化的CGE模型,以模拟和优化不同大气自净能力情境下的氮氧化物税率设定。经研究表明,在充分利用大气自净能力的前提下,内蒙古地区的氮氧化物税率优化结果如下:2021年为8.36元/污染当量,2022-2025年为7.6912元/污染当量,2026-2030年为7.3836元/污染当量。此外,税率优化对出口产生较大影响,但同时能提升投资,对GDP的综合影响不大。因此,应适当提高内蒙古地区的氮氧化物税率,并构建动态的税率调节机制。

Stable-thickness study of masonry block on the inner slope of dikes

Dike failure caused by overtopping is likely to result in major casualties and property losses.Aiming at this fact,a series of physical model experiments were conducted on stable thickness of masonry block on the inner slope of the dike.According to the erosion of block embankment with different thicknesses,the relation between the stable thickness of masonry block pitching of the inner slope and the average overtopping discharge is discussed.New equations subject to irregular waves are presented for average overtopping discharge,based upon the analysis of mean overtopping discharge and comparison of present overtopping discharge formulas at domestic and abroad.Finally,a calculation equation of the stable thickness of the dry masonry block stone of inner slope subject to irregular waves is given.In conclusion,the formula matches well with the experiment result,which is capable of functioning as an important reference for structure designs of the dike in China.

Influences of the inner diameter of the solid shielding tube on the characteristics of the radio-frequency cold atmospheric plasma jet

Active control of the local environment of the cold atmospheric plasma(CAP) jet is of great importance in actual applications since the CAP operates in an open atmosphere with the inevitable entrainment of the surrounding cold air. In this paper, the solid shielding effects of the cylindrical quartz tubes with different inner diameters on the characteristics of the CAP jets driven by a radio-frequency(RF) power supply are studied experimentally. The experimental results show that the total length of the shielded plasma jet can be increased significantly by an appropriate combination of the quartz tube inner diameter and that of the plasma generator nozzle exit with other parameters being unchanged. This phenomenon may be qualitatively attributed to the loss of diffusion of the charged particles in the radial direction under different inner diameters of the quartz tubes. Compared with the plasma free jet, the plasma shielding jet is produced with optimized parameters including longer plasma jet length, higher concentrations of chemically reactive species, higher rotational, vibrational, and electron excitation temperatures when the inner diameters of the solid shielding tube and the generator nozzle exit are the same. A maximum plasma jet length of 52.0 cm is obtained in contrast to that of 5.0 cm of the plasma free jet in this study. The experimental results indicate that the solid shielding effect provides a new method for the active control of the local environment of the RF-CAP jet operating in an open atmosphere.

气田采出水处理技术研究进展

概述了气田采出水的来源及特点,总结了国内外气田采出水处理现状以及最新发展动态,阐述了回注地层、净化外排和资源化利用等典型处理方法和技术路线,分析了气田采出水膜法脱盐工艺和生物处理技术的最新进展。结合针对普光气田采出水开发的深度处理资源化利用成套技术及应用效果,指出气田采出水处理应以资源化利用为未来研究方向。

工作气压对管内壁沉积Si/O-DLC薄膜结构与性能的影响

目的探讨工作气压对管内等离子体放电光学现象以及Si/O-DLC(Si and O Incorporated DLC,Si/O-DLC)薄膜结构与性能的影响,为获得管内高质量、均匀的Si/O-DLC薄膜制备工艺技术提供指导。方法利用空心阴极等离子体增强化学气相沉积(Hollow Cathode Plasma Enhanced Chemical Vapor Deposition,HC-PECVD)技术,通过改变工作气压在管内沉积Si/O-DLC薄膜。利用高速摄像机记录并对比不同工作气压下管内等离子体放电光学现象。通过SPM、XPS和Raman光谱仪表征不同工作气压下薄膜的三维立体表面形貌和微观结构,并利用SEM、纳米压痕仪以及划痕测试系统,对比研究管内Si/O-DLC薄膜的硬度、弹性模量、膜基结合力以及沿管轴向的薄膜厚度分布。结果随着工作气压的上升,管径向中心处亮斑面积和光强先增大增强后趋于缩小暗淡。在不同工作气压下,均能够在管内获得表面光滑的Si/O-DLC薄膜,粗糙度为3~10 nm。随着工作气压的上升,管内Si/O-DLC薄膜的平均厚度从1.42μm增大到2.06μm,且沿管轴向的薄膜厚度分布均匀度从24%显著提高到65%;不同工作气压下管内Si/O-DLC薄膜沿管轴向平均硬度呈先增大后减小的趋势,总体平均硬度可达(14±1)GPa。管内Si/O-DLC薄膜在工作气压上升到25 mTorr时获得较高的平均膜基结合力。结论改变工作气压能够显著影响管内壁Si/O-DLC薄膜的结构与性能,当工作气压为25 m Torr时,在管内获得均匀性最优、结合力较高的Si/O-DLC薄膜。

Velocity and pressure distributions in discharge tunnel of rotary-obstruction composite inner energy dissipation

On the basis of model test and theoretical analysis of velocity and pressure distributions,an hypothesis is presented that the distribution of tangential velocity in radial direction seems to be a combinational distribution of a quasi-free vortex and a quasi-forced vortex for the discharge tunnel of rotary-obstruction composite inner energy dissipation.The variations of corresponding parameters about the hypothesis are obtained under test conditions in this paper.The formula of pressure distribution in radial direction is deduced theoretically,and the theoretical values of pressure distribution computed by the formula are well consistent with the measured ones,showing that the formula is correct and can be applied to the computation and analysis of pressure distribution of this discharge tunnel.

黄河龙羊峡和刘家峡水库凌汛关键期优化调度研究

2000年以来黄河上游来水形势、宁蒙河段河道状况和凌情发生了较大变化,而凌汛期正值青海省用电高峰,水力发电所需水量大,迫切需要开展凌汛期龙羊峡、刘家峡水库优化调度研究。通过分析凌汛期水库调度、气温变化和河道条件等对黄河凌情的影响,研究确定黄河宁蒙河段适宜封河流量、开河关键期压减水库下泄流量的时机和力度,提出了龙羊峡、刘家峡水库封开河关键期优化调度建议,并在此基础上编制多种情景(上游来水、气温类型和河道条件组合)下,龙羊峡、刘家峡水库优化调度预案。2019—2020年度、2022—2023年度在汛期来水分别偏多、偏少情况下水库优化调度实践表明,凌汛期优化调度方案可以在保证黄河宁蒙河段防凌安全的前提下,明显提高黄河上游梯级水库群发电效益。

黄河内蒙古段造床流量变化及其影响因素

造床流量是反映河床冲淤的表征指标,也是河道整治的主要参数。基于1960—2019年实测数据,运用改进马卡维耶夫法、平滩水位法、地貌功法,计算并分析了石嘴山、巴彦高勒、三湖河口、头道拐水文站造床流量。结果表明:时间上,1960—1989年、2010—2019年造床流量为2100~3540 m^(3)/s,中水河槽冲刷,1990—2009年造床流量为740~1300 m^(3)/s,河槽淤积萎缩严重;空间上,造床流量呈现上站大于下站的特点;造床流量受来水量影响较大,在汛期水量低于105亿m 3的情况下,可以通过刘家峡、龙羊峡、海勃湾水库三库联调适当增大汛期来水量,强化黄河内蒙古段造床作用。研究结果显示改进马卡维耶夫法物理意义明确,计算结果相对合理,可为冲积性河流造床流量确定及黄河内蒙古段河道治理提供参考。

Effect of tube-electrode inner diameter on electrochemical discharge machining of nickel-based superalloy

Nickel-based superalloys are widely employed in modern aircraft engines because of their excellent material characteristics, particularly in the fabrication of film cooling holes. However, the high machining requirement of a large number of film cooling holes can be extremely challenging. The hybrid machining technique of tube electrode high-speed electrochemical discharge drilling (TEHECDD) has been considered as a promising method for the production of film cooling holes. Compared with any single machining process, this hybrid technique requires the removal of more complex machining by-products, including debris produced in the electrical discharge machining process and hydroxide and bubbles generated in the electrochemical machining process. These by-products significantly affect the machining efficiency and surface quality of the machined products. In this study, tube electrodes in different inner diameters are designed and fabricated, and the effects of inner diameter on the machining efficiency and surface quality of TEHECDD are investigated. The results show that larger inner diameters could effectively improve the flushing condition and facilitate the removal of machining by-products. Therefore, higher material removal efficiency, surface quality, and electrode wear rate could be achieved by increasing the inner diameter of the tube electrode. (C) 2015 The Authors. Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.

黄河宁蒙河段2011-2020年凌情演变规律分析

凌汛是黄河冬春季最突出、最主要的汛情,其中宁蒙河段是黄河防凌的重点河段。2011-2020年黄河宁蒙河段凌情出现了一系列新规律、新特点,主要呈现流凌封河日期推迟、开河日期提前、封冻历时和封河长度缩短、最大冰厚变薄、槽蓄水增量减小、开河历时变长、开河凌峰及最大10 d水量减小等特征。从热力因素、水流动力因素、河道边界条件和水库调度影响等方面分析2011-2020年凌情演变的主要驱动因素,结果表明:气温整体偏高且上下游温差增大是宁蒙河段流凌封河日期推迟、开河日期提前、封冻历时和封河长度缩短、最大冰厚变薄的主要原因;凌汛期来水偏多,月际分配发生明显变化,在一定程度上造成了流凌封河日期推迟、开河历时变长、开河凌峰及最大10 d水量减小;河道条件明显改善,有利于冰下过流能力的恢复,造成槽蓄水增量近年来呈减小趋势;海勃湾水库的投入运用在一定程度上改变了坝址以下河段的冰凌演变规律,同时科学合理的水库调度也为平稳封开河创造了有利条件。

天然气净化厂高盐环胺废液处理工艺研究

天然气净化厂尾气氧化吸收工艺中会产生大量高盐环胺废液,主要为胺液净化装置中树脂再生产生的废液,主要为有机胺及硫酸盐,可生化性差。以氧化吸收工艺产生的高盐环胺废液为处理对象开展了全流程工艺的研究,形成了“预处理→反渗透脱盐→电渗析膜浓缩分离→组合氧化降解→蒸发结晶”的尾气废液组合处理工艺。废液经尾气废液组合处理工艺处理后,再通过生化处理,最终产水化学需氧量降至81.5 mg/L,氨氮浓度小于1 mg/L,Na_(2)SO_(4)浓度降至0.23 g/L,实现达标排放。研究结果可为后期工程化设计提供技术指导。

降低VVER型核电机组蒸汽发生器排污水净化系统再生废水量的研究

VVER型核电机组的蒸汽发生器排污水净化系统树脂床再生后,需要进行阳离子交换树脂冲洗及阴阳离子交换树脂联合冲洗。冲洗过程中所使用的除盐水pH值接近于阳离子交换树脂冲洗终点要求,且阴阳离子交换树脂联合冲洗时,阴离子交换树脂再生液NaOH冲洗困难,导致树脂床再生过程废水量较大、树脂床恢复备用时间较长。为此论证了降低阳离子交换树脂冲洗终点的pH值及树脂床联合冲洗排至凝结水的可行性,以此降低VVER型核电机组蒸汽发生器排污水净化系统再生废水量。