空气源高频圆管型DBD臭氧产生的实验研究

电源频率和放电管长度是介质阻挡放电(DBD)臭氧产生的两个重要影响因素,在前期的研究基础上,采用合适的放电管长度和电源频率进行实验研究。实验研究了干空气源放电管长度、放电电压和气体流量对臭氧产生的影响,并进行了系统优化。研究结果表明:放电管长度由500 mm变为200 mm,在几乎不降低臭氧浓度下放电平均功率约降低了60%;臭氧浓度随放电电压和气体流量的增大先增大后降低;当流量为200 L/h、放电电压为2 698 V时,臭氧浓度与臭氧产率同时达到相对较高值,此时,臭氧浓度为5.3 g/m3时,臭氧产率为43.62 g/kWh。     

Numerical investigation on the effect of gas parameters on ozone generation in pulsed dielectric barrier discharge

Pulsed dielectric barrier discharge is a promising technology for ozone generation and is drawing increasing interest. To overcome the drawback of experimental investigation, a kinetic model is applied to numerically investigate the effect of gas parameters including inlet gas temperature, gas pressure, and gas flow rate on ozone generation using pulsed dielectric barrier discharge. The results show that ozone concentration and ozone yield increase with decreasing inlet gas temperature, gas pressure, and gas flow rate. The highest ozone concentration and ozone yield in oxygen are about 1.8 and 2.5 times higher than those in air, respectively. A very interesting phenomenon is observed: the peak ozone yield occurs at a lower ozone concentration when the inlet gas temperature and gas pressure are higher because of the increasing average gas temperature in the discharge gap as well as the decreasing reduced electric field and electron density in the microdischarge channel. Furthermore, the sensitivity and rate of production analysis based on the specific input energy (SIE) for the four most important species O₃, O, O(1D), and O₂(b¹∑) are executed to quantitatively understand the effects of every reaction on them, and to determine the contribution of individual reactions to their net production or destruction rates. A reasonable increase in SIE is beneficial to ozone generation. However, excessively high SIE is not favorable for ozone production.     

磁力搅拌柠檬酸法鳙鱼鱼鳞脱钙的工艺探讨

以柠檬酸为脱钙剂,在磁力搅拌作用下进行鳙鱼鱼鳞的脱钙研究.先后采用单因素实验和正交试验法考察了固液比、柠檬酸质量分数、搅拌时间和搅拌速度等工艺参数对脱钙率的影响并进行了优化.结果表明：最佳工艺参数确定为固液比1∶20 g/mL、柠檬酸质量分数10％、搅拌时间60 min和搅拌速度900 r·min-1,在此条件下,脱钙率高达92.57％.正交试验的方差分析表明上述四因素对脱钙率的影响精度均为不显著,但通过极差分析和F1值比较均可发现四因素对脱钙率影响程度的相对大小为柠檬酸质量分数＞固液比＞搅拌时间＞搅拌速度.     

石墨烯量子点的抑菌特性

石墨烯量子点（GQDs）由于其独特的物理结构，使其在抗菌领域得到广泛的关注。以石墨粉为原料，采用震荡冲击法制备GQDs,探究在808 nm激光的照射下，GQDs对大肠杆菌的抑制效果。结果表明：1.0 mg·mL-1的GQDs在光照20 min的情况下，可将大肠杆菌完全杀灭，而将光照时间提高至25 min时，0.6 mg·mL-1的GQDs即可将大肠杆菌完全杀灭。若提高GQDs质量浓度或光照时间，GQDs可短时、高效地杀灭抑菌。GQDs在抑菌过程中，不仅能产生活性氧，其自身结构也能对大肠杆菌的细胞膜造成破坏，在抗菌方面具有广阔的发展前景。     

混合放电臭氧发生器中臭氧产生过程的传热数值模拟

为揭示混合放电臭氧高效发生的电能转换和传热机理,采用有限体积法数值求解质量、动量和能量守恒方程,实现对混合放电臭氧发生进行传热分析,并实验验证了该方法的可行性。研究结果表明:气体进入两放电间隙后温度逐渐升高,且两放电间隙温度相差较大,内放电空间平均温度比外放电空间平均温度平均高6.38 K;中心电极、内电介质、外介电质和外电极各部分内部径向温差较小;混合放电仅36.14%的电能转换为热能,其中气体从3根放电管中携带的热量分别为9.85%,7.39%和4.78%,气体经过3根放电管后最高温度仅为313.2 K。混合放电电能转化率高、气体温度相对较低,是一种非常有前途的臭氧发生形式。     

臭氧氧化结合化学吸收同时脱除烟气中多种污染物的经济性分析

臭氧氧化结合化学吸收已被证明能同时脱除烟气中多种污染物,臭氧产生能耗大抑制了该工艺的进一步推广应用。针对此问题,开发了两种低耗高效臭氧发生技术：高频高压臭氧发生技术和脉冲流光放电臭氧发生技术。再此基础上对臭氧氧化结合化学吸收同时脱除烟气中多种污染物进行经济性分析,在达到同等脱硫率和脱硝率,且脱汞率远大于电子束的同时,高...     

惰性气体对氧气介质阻挡放电臭氧生成的影响(英文)

This paper reports the results of an experimental study of the effect of inert gases He,Ar and Kr on ozone generation in a Dielectric Barrier Discharge(DBD) fed by pure oxygen.The chemical reaction mechanisms related to the process of ozone generation are discussed.The experimental results show that ozone concentration decrease with decreasing oxygen content in all He+O2,Ar+O 2 and Kr+O 2 mixtures mainly owing to the decrease of oxygen content.The conversion ratio of oxygen into ozone increases with increasing oxygen content in He+O2 mixtures,but the addition of Ar and Kr can improve the conversion ratio due to the increase of free electrons density and excited oxygen molecules required for ozone formation through ionization and Penning effect.The effect of Kr is more significant for the lower first ionization energy of metastable state compared with other gases.It is probable that the ozone concentration,and ozone production efficiency increase with Kr addition when the reduced electric field and mean electron energy are high enough.     

化学镀镍-磷-锌合金工艺条件的优化及其动力学研究

考察了化学镀Ni-P-Zn的镀液组成、温度以及pH对镀层沉积速率和耐蚀性能的影响,确定了适宜的参数为:硫酸镍0.103mol/L、次磷酸钠0.226mol/L、硫酸锌0.028mol/L和柠檬酸三钠0.29mol/L,温度90°C,pH=9.0。在此条件下,镀层沉积速率为11.5μm/(cm2·h),镀层中锌的质量分数为11.9%,钝化后镀层在5%(质量分数)NaCl溶液浸泡试验中的耐腐蚀时间达到1440h。建立了Ni-P-Zn沉积速率的动力学方程。经实验验证,该数学模型与实验结果吻合度较好,对Ni-P-Zn沉积过程的调节和产物的控制具有一定的指导意义。     

Electron Transport Coefficients and Effective Ionization Coefficients in SF6-O2 and SF6-Air Mixtures Using Boltzmann Analysis

The electron drift velocity, electron energy distribution function （EEDF）, densitynormalized effective ionization coefficient and density-normalized longitudinal diffusion velocity are calculated in SF6-O2 and SFs-Air mixtures. The experimental results from a pulsed Townsend discharge are plotted for comparison with the numerical results. The reduced field strength varies from 40 Td to 500 Td （1 Townsend=10-17 V.cm2） and the SF6 concentration ranges from 10% to 100%. A Boltzmann equation associated with the two-term spherical harmonic expansion approximation is utilized to gain the swarm parameters in steady-state Townsend. Results show that the accuracy of the Boltzlnann solution with a two-term expansion in calculating the electron drift velocity, electron energy distribution function, and density-normalized effective ionization coefficient is acceptable. The effective ionization coefficient presents a distinct relationship with the SF6 content in the mixtures. Moreover, the E/Ncr values in SF6-Air mixtures are higher than those in SF6-O2 mixtures and the calculated value E/Ncr in SF6-O2 and SF6-Air mixtures is lower than the measured value in SFB-N2. Parametric studies conducted on these parameters using the Boltzmann analysis offer substantial insight into the plasma physics, as well as a basis to explore the ozone generation process.     

SF6对介质阻挡放电臭氧生成的影响（英文）

The influence mechanism of a small amount of SF6 on ozone generation in oxygen or air discharge is investigated.Some results are obtained by probing into the number of the high-energy electrons,which have the sufficiency energy for generating ozone.Introducing a small amount of SF6 into oxygen sharply decreases the number of high-energy electrons,because the electron density decreases sharply while the mean electron energy remains constant due to higher breakdown voltage and lower discharge power,and some high-energy electrons are consumed by the excitation and attachment of SF6.In contrast,when a small amount of SF6 is added into dry air discharge,despite the consumption of the excitation and attachment of SF6,the number of high energy electrons increases sharply,which is attributed to the higher mean electron energy and electron density resulted from higher breakdown voltage and discharge power.When the volume fraction of SF6 increases from 0 to 2.22%,the ozone mass concentration and the ozone yield increase by 45.7% and 29.7%,respectively.Therefore,though the oxygen source should avoid the presence of SF6,adding a small amount of SF6 can improve the ozone mass concentration and the efficiency of ozone generation.