Treatment of simulated wastewater containing Reactive Red 195 by zero-valent iron/activated carbon combined with microwave discharge electrodeless lamp/sodium hypochlorite

A comparative study of treatment of simulated wastewater containing Reactive Red 195 using zero-valent iron/activated carbon （ZVI/AC）, microwave discharge electrodeless lamp/sodium hypochlorite （MDEL/NaCIO） and the combination of ZVI/AC- MDEL/NaCIO was conducted. The preliminary results showed the two steps method of ZVI/AC-MDEL/NaCIO had much higher degradation efficiency than both single steps. The final color removal percentage was nearly up to 100% and the chemical oxygen demand reduction percentage was up to approximately 82%. The effects of operational parameters, including initial pH value of simulated wastewater, ZVI/AC ratio and particle size of ZVI were also investigated. In addition, from the discussion of synergistic effect between ZVI/AC and MEDL/NaCIO, we found that in the ZVI/AC-MEDL/NaCIO process, ZVI/AC could break the azo bond firstly and then MEDLfNaCIO degraded the aromatic amine products effectively. Reversing the order would reduce the degradation efficiency.

Photolysis of H_2S with interior microwave discharge electrodeless lamps

The luminescent properties of microwave discharge electrodeless mercury lamp（MDEL-Hg） which was ignited within the resonant cavity and photolysis of hydrogen sulfide with low concentration were studied in this paper.Experiment results indicated that the Interior MDEL-Hg could be made the best of energy utihzation and the efficiency of photolysis of H2S was very significant under the experimental conditions with the initial H2S concentration of 7.9 mg m^-1.With residence time of 1.5 s,the removal efficiency of hydrogen sulfide was 91%,the absolute removal amount（ARA） was 3.24μg s^-1 and the energy consumption was 58.23 mg（kWh）^-1.

The near-infrared spectra and distribution of excited states of electrodeless discharge rubidium vapour lamps

The population ratio between the excited states of rubidium in the electrodeless discharge rubidium vapour lamp is calculated according to the near-infrared spectra in the region of 780-1550 nm. By using a 1529 nm laser, we measure the density of natural rubidium atoms at the 5P3/2 level. The populations of different excited states are then clarified.

Influence of the Gas Mixture Ratio on the Correlations Between the Excimer XeCl Emission and the Sealed Gas Temperature in Dielectric Barrier Discharge Lamps

For dielectric barrier discharge lamps filled with various gas mixture ratios, the correlations between the excimer XeCl* emission and the sealed gas temperature have been founded, and a qualitative explication is presented. For gas mixture with chlorine larger than 3%, the emission intensity increases with the sealed gas temperature, while with chlorine about 2%, the emission intensity decreases with the increase in the gas temperature, and could be improved by cooling water. However, if chlorine is less than 1.5%, the discharge appears to be a mixture mode with filaments distributed in a diffused glow-like discharge, and the UV emission is independent on the gas temperature.

Novel Automotive High Intensity Discharge(HID) Lamps with Electronic Ballasts

A new scheme of automotive high intensity discharge(HID) lamps with electronic ballasts is proposed. The design of the proposed ballast and some experimental results are presented. The proposed scheme is consisted of the high frequency DC-DC converter and the low frequency DC-AC inverter. This system separates the input voltage of the ignitor from DC link voltage using auxiliary winding, then it could use the lower voltage rating power devices for HID lamp ballast system and reduce the size of HID lamp ballast. The proposed ballast controller using micro-controller unit(MCU) controls the frequency to operate the DC-DC converter in critical conduction mode, which reduces the noise of the circuit and improves the efficiency by 2%~4%.

Population Distribution of Excited States in Cs Electrodeless Discharge Lamp

We measure the intensity of fluorescence spectral lines of Cs atoms in an electrodeless discharge lamp from visible light to the near-infrared region of 400-100Ohm. To build an excited state Faraday anomalous dispersion optical filter, the population ratios between the excited states are calculated by rate equations and the spontaneous transition probabilities. The electrodeless discharge lamp with populations in the excited states can be used to realize the frequency stabilization reference for lasers at multiwavelength and the excited state Faraday anomalous dispersion optical filter for submarine communication applications in blue-green wavelengths to simplify the system.

基于平均电流控制的恒功率控制电路设计

为解决HID灯的老化及灯的伏安特性变化引起的功率漂移问题,基于Buck降压变换器的平均电流控制模式,设计并制作了一款具有恒功率控制能力的数字控制电子镇流器驱动电路,包含两个控制环路:内电流环路用于维持稳定驱动,外功率环路用于维持灯在其使用期间的功率恒定,并根据Buck降压变换器DCM模式下的小信号模型,以PI算法作为数字补偿器,完成补偿环路设计,保证电路输出稳定性。为抑制声共振,该电路结构采用三级式结构的电子镇流器,以低频方波驱动。设计和测试结果表明,该电子镇流器驱动电路可实现450 W的恒功率控制,误差值小于3%。该电子镇流器驱动电路结构简单,可靠性高,可适用于450 W HID灯驱动。

吊舱式一体化灯抽运固体激光器高效脉冲电源的设计

为了实现机载脉冲激光介质高效抽运电源的小型轻量化,采用一体化结构设计方法,设计了一套为吊舱式灯抽运固体激光器脉冲氙灯提供抽运能量的高效脉冲电源系统。对氙灯放电特性及器件参数进行了理论分析和实验验证,获得了氙灯放电主回路关键器件参数,试制了原理样机并进行了联调实验。结果表明,电源系统总质量约为48 kg,电容充电时间为3.76 s,氙灯放电峰值电流为3.6 kA,电流脉宽为1.06 ms;实际测试数据与理论数据基本一致,脉冲电源系统放电回路参数设计合理。该关键技术具有可行性,采用一体化结构设计方法后,脉冲电源系统体积重量能满足特殊设备的使用需求。

Low pressure mercury–argon electrodeless fluorescent lamp simulation using the finite volume method

A finite volume model of a low pressure Ar-Hg electrodeless lamp with external coils is established. The physical configuration is similar to the OSRAM/ENDURA 70 W lamp. A Maxwellian energy distribution is assumed. Two dimensional behaviors of the most important plasma parameters such as the electron density, the electron temperature and the most important mercury states are discussed. Results are in good agreement with former studies and the general understanding in this area. Also, the influence of the argon pressure is studied. Based on the simulation, the population of the main resonance state, Hg （63p1） depends on the argon pressure and the optimized value is about 300 mTorr.

Comparison Between X-rays Absorption and Emission Spectroscopy Measurements on a Ceramic Envelop Lamp

Burners of metal halide lamps used for illumination are generally made of polycrystalline alumina ceramic （PCA） which is translucent to visible light. We show that the difficulty of selecting a line of sight through the lamp prevents the use of optical emission diagnostic. X-rays photons are mainly absorbed and not scattered by PCA. Absorption by mercury atoms contributing to the discharge allowed us to determine the density of mercury in the lamp. By comparing diagnostic methods, we put in evidence the difficulty of taking into account the scattering of light mathematically.

Glass Melting Phenomena of a Fluorescent Lamp and a Protection Method by a Metal Ring

The formation mechanism of the discharge spot at a bottom of a lead wire in a fluorescent lamp at end-of-life is investigated. When the lamp at end-of life is ignited by applying high voltage, glow-like discharge is formed on the surface of the lead wire. A few seconds later, a bright spot is formed at the bottom 0fthe lead-wire. Then the stem glass on which the lead-wires are mounted begins to melt. High electric field is formed between the surface of the lead-wire and the stem glass surrounding the lead wire. Then discharge spot will be formed at the contact portion of the lead wire to the stem glass by this high electric field. To prevent discharge spot formation at the bottom of the lead wire, the metal ring is set to encircle the lead wire and is connected to the lead wire potential through a resistor. By this configuration, discharge spot formation is effectively suppressed. The mechanism for preventing hot discharge spot formation by the metal ring is discussed.

一种适用于介质阻挡放电型准分子灯的双极性脉冲式供电电源

如何为介质阻挡放电(DBD)负载构建结构简单的高性能供电电源一直是DBD应用领域面临的难题。通过利用DBD负载呈容性这一特性,结合DBD负载对激励波形特殊需求的基础上,本文提出了一种适用于DBD负载的双极性脉冲式供电电源。该供电电源仅由一个直流电源、两个功率开关器件、两个二极管和一个升压变压器构成。为了在DBD负载上生成同时具有高上升率、下降率和间歇时间的高频高压双极性脉冲激励,本文设计了该供电电源的工作时序,并进行理论分析和以准分子灯为负载的实验装置来验证供电电源的可行性。实验结果表明,本文构造的供电电源不仅能在准分子灯上生成期望的脉冲激励,而且实现了所有功率开关器件工作在软开关状态。此外,本文构造的供电电源除了具有元器件少的优点,而且能实现准分子灯放电光强线性调节和充分发挥准分子灯性能的特征。

压制压力对放电灯用阴极钨骨架孔隙结构和性能的影响

孔隙结构均匀的钨骨架是制备高性能电子阴极及放电灯的关键材料。本文系统研究了压制压力对钨骨架孔隙结构、力学性能及放电灯性能的影响。结果表明,随压制压力增大,钨骨架的孔隙率和平均孔径减小,显微硬度及抗压强度提高,孔隙分布均匀性指数先增大后减小。压制压力为500 MPa时,钨骨架的孔隙结构和力学性能最佳,孔隙率为26.29%,平均孔径为1.24μm,孔隙分布均匀性指数为4.17,显微硬度为1506 MPa,抗压强度为810 MPa。该钨骨架作为阴极基体制备的氙气灯在连续闪烁50万次的情况下没有出现漏闪,阴极发射性能稳定,且未达到寿命极限,与现有阴极相比寿命显著提升。

The roles of active species in photo-decomposition of organic compounds by microwave powered electrodeless discharge lamps

Knowledge of the effective radiation spectrum irradiating substrates from microwave powered electrodeless discharge lamps（MEDLs）, and the active species that directly oxidize substrates in the photolytic process, is fragmentary and unclear. In this work, we conducted a comparative study using MEDLs made with quartz envelopes（MEDL-quartz） and with borosilicate Pyrex envelopes（MEDL-Pyrex） targeting the degradation of Rhodamine B（Rh B）via radical-extinguishing tests. We found that UVC/UVB radiation is essential to generate·OH and H2O2 in the MEDL-quartz system. The degradation of Rh B mostly originates from·OH species, which account for a contribution of 53.8%, while the remaining contribution is attributed to oxidation by H2O2 and direct photolysis. This degradation is influenced by several parameters. Acidic and neutral p Hs, but not extreme alkaline p H, benefit the degradation. To ensure a high intensity of UVC/UVB, the optimum ratio of the MEDL volume to the aqueous solution volume（VL/VS） is 0.4. Concentrations of 0.15-0.20 mmol/L of Rh B are suitable to obtain an effective quantum absorbance in the MEDL-quartz system,showing a high decomposition rate of 5.6 × 10^-3（mmol/L）min-1. Moreover, two other substrates, Reactive Brilliant Red X-3B and Safranine T, were tested and found to be efficiently degraded in the MEDL-quartz system.

Distribution of populations in excited states of electrodeless discharge lamp of Rb atoms

The intensity of fluorescence spectral lines of Rb atoms in the region of 350-1110nm is measured in eletrodeless discharge lamp. The population ratio between the excited states is calculated according to the spontaneous transition probabilities with rate equations. At the same time, the population density of energy level is also obtained. The results provide the potential applications of electrodeless discharge lamp in atomic filter and optical frequency reference at higher excited states without a pumping laser.

Atomic population distribution of excited states in He electrodeless discharge lamp

Population ratios between excited states are measured to build the excited state Faraday anomalous dispersion optical filter(ESFADOF). We calculate these values between the excited states according to the spontaneous transition probabilities using rate equations and the measured intensities of fluorescence spectral lines of He atoms in an electrodeless discharge lamp in the visible spectral region from 350 to 730 nm. The electrodeless discharge lamp with populations in excited states can be used to realize the frequency stabilization reference of the laser frequency standard. This lamp can also build ESFADOFs for submarine communication application in the blue-green wavelength to simplify the system without the use of a pump laser.

Intelligent Controller of Digital High Intensity Discharge Lamp

High intensity discharge (HID) lamps include these types of electrical lamps: mercury vapor, metal halide (also hydraulic quantity indicator),

Intelligent Controller of Digital High Intensity Discharge Lamp

High-intensity discharge (HID) lamps include these types of electrical lamps: mercury vapor, metal halide (also HQI), high-pressure sodium, low-pressure sodium and less commonly, xenon short-arc lamps. The light-producing element of these lamp types is a well-stabilized arc discharge contained within a refractory envelope (arc tube) with wall loading in excess of 3 W/cm (19.4 W/in.). Compared to fluorescent and incandescent lamps, HID lamps produce a much larger quantity of light in a relatively small package. With tests made by the National Quality Supervision

微波辅助光催化降解4-氯酚的研究

采用了一种新的水处理技术微波辅助光催化(MW/UV/P25)降解4-氯酚(4CP)模拟废水。初始质量浓度为30mg/L的4CP在微波光催化下发生了降解,反应120min,4CP的降解率达到82.85%,Cl-质量浓度增加值为7.95mg/L。4CP的降解率与溶液的pH、通气条件、紫外灯光照度等因素有关,外加H2O2氧化剂能够加速4CP的降解。微波辅助光催化降解4CP服从一级反应动力学方程。