开孔阳极铝电解槽熔体中气液两相流数值模拟

目前的电解铝生产工艺以氧化铝为原料，在直流电的作用下，熔融电解质中的氧化铝在高温环境下与碳阳极发生复杂的电化学反应，主要在阳极底掌析出二氧化碳L1J。二氧化碳气体从阳极底掌产生到逸出电解质表面的过程中，一方面会不断搅动电解质熔体，阳极气泡与电解质相互发生复杂的传热传质作用，有利于氧化铝颗粒在高温熔体中均匀快速地溶解和扩散运动；另一方面，

孔阳极大气压直流辉光放电研究

为得到一种简单可靠的大气压直流辉光放电方式,并提高直流辉光放电在织物表面处理领域的实用性,提出了一种孔阳极辅以轴向气流的直流大气压辉光放电装置。实验并记录和讨论了放电图像和放电电流波形,还根据约化伏安特性曲线确定了辉光转化的阈值电压。结果表明孔阳极与轴向气流配合可有效消除辉光放电的不稳定性,产生稳定的大气压直流辉光。另外,考察了放电发射光谱和电极轴线上的光强分布,并确认光强分布具有典型的辉光特征。

低银铅钙带孔阳极的工业应用

介绍低银铅钙带孔阳极在锌电积工厂中的应用情况, 并对该阳极的特点进行了总结。

纳米微孔铝阳极氧化膜的制备及性能

研究了作为功能膜使用的微孔铝阳极氧化膜的制备及性能。在 4%磷酸阳极氧化铝膜基础上 ,3 .5 %盐酸电解浸蚀得到支撑氧化铝的基体 ,2 %碱处理去除无孔阻挡层 ,3 5 0℃热处理脱水氧化膜 ,制备了具有纳米级孔径和较好机械强度的复合氧化铝分离膜。

Preparation and electrochemical lithium storage performance of porous silicon microsphere composite with metal modification and carbon coating

This work adopts a multi⁃step etching⁃heat treatment strategy to prepare porous silicon microsphere com⁃posite with Sb⁃Sn surface modification and carbon coating(pSi/Sb⁃Sn@C),using industrial grade SiAl alloy micro⁃spheres as a precursor.pSi/Sb⁃Sn@C had a 3D structure with bimetallic(Sb⁃Sn)modified porous silicon micro⁃spheres(pSi/Sb⁃Sn)as the core and carbon coating as the shell.Carbon shells can improve the electronic conductivi⁃ty and mechanical stability of porous silicon microspheres,which is beneficial for obtaining a stable solid electrolyte interface(SEI)film.The 3D porous core promotes the diffusion of lithium ions,increases the intercalation/delithia⁃tion active sites,and buffers the volume expansion during the intercalation process.The introduction of active met⁃als(Sb⁃Sn)can improve the conductivity of the composite and contribute to a certain amount of lithium storage ca⁃pacity.Due to its unique composition and microstructure,pSi/Sb⁃Sn@C showed a reversible capacity of 1247.4 mAh·g^(-1) after 300 charge/discharge cycles at a current density of 1.0 A·g^(-1),demonstrating excellent rate lithium storage performance and enhanced electrochemical cycling stability.

PMMA含量对水系流延IT-SOFC性能的影响

通过向阳极添加单一分散性的球形造孔剂PMMA改善阳极的微观结构,研究不同含量的PMMA对阳极的孔隙率、显微结构、电性能的影响。文中分别制备了造孔剂(PMMA)含量分别为6wt.%、8wt.%、10wt.%和12wt.%四种阳极材料的单电池,通过测试阳极还原前的开口气孔率分别为17vol.%,22.4vol.%,30.6vol.%和42.1vol.%;单电池的最大功率密度分别为0.66W/cm2、0.78W/cm2、1.15W/cm2和1.01W/cm2;极化电阻分别为1.12Ω.cm2、1.03Ω.cm2、0.88Ω.cm2和1.02Ω.cm2。实验结果表明:以单一分散性的球形PMMA为SOFC阳极材料的造孔剂,其最佳添加量为10wt.%,所制备的单电池可以获得最佳的电化学性能,即以3%H2O+H2为燃料气,750℃下,单电池的开路电压(OCV)为1.01V,最大功率密度为1.15W/cm2,极化电阻为0.88Ω.cm2。

Fabrication and photodegradation properties of TiO_2 nanotubes on porous Ti by anodization

Both Ti foil and porous Ti were anodized in 0.5%HF and in ethylene glycol electrolyte containing 0.5%NH4F(mass fraction) separately. The results show that TiO2 nanotubes can be formed on Ti foil by both processes, whereas TiO2 nanotubes can be formed on porous Ti only in the second process. The overhigh current density led to the failure of the formation nanotubes on porous Ti in 0.5%HF electrolyte. TiO2 nanotubes were characterized by SEM and XRD. TiO2 nanotubes on porous Ti were thinner than those on Ti foil. Anatase was formed when TiO2 nanotubes were annealed at 400 °C and fully turned into rutile at 700 °C. To obtain good photodegradation, the optimal heat treatment temperature of TiO2 nanotubes was 450 °C. The porosity of the substrates influenced photodegradation properties. TiO2 nanotubes on porous Ti with 60% porosity had the best photodegradation.

BLUE－VIOLET LIGHT EMISSION FROM POROUS SILICON

Porous silicon samples are made on Si wafers with different resistivities under different anod ic-react ion conditions. Visible photoluminescent spectra of porous silicon (PS) at room temperature are measured using a fluorescent spectrograph where blue-violet light is observed. The decision of the resistivity of Si substrates is provided.

解决枪管亚口补镀铬的方法

提出了一种枪管亚口镀件不用内孔阳极，借助阴极边缘效应，在外阳极的作用下进行补镀铬的方法，解决了传统工艺无法补镀的问题。介绍了枪管亚口在补镀操作中应注意的问题及镀层测试结果，并对补镀铬所产生的某些问题进行了探讨。实践表明：采用本法将提高枪管镀铬成品率约5％-10％。

Design and construction of a film of mesoporous single-crystal rutile TiO_2 rod arrays for photoelectrochemical water oxidation

A film of mesoporous single-crystal rutile TiO2 rod arrays supported on a transparent conductive glass substrate was synthesized with the assistance of a template layer of closely packed silica nanospheres. This film was used as a photoanode and showed significant improvement for photoelectrochemical water oxidation compared with a reference film of nonporous single-crystal rutile TiO2rod arrays.

银电解优化工艺生产实践

主要介绍了通过对工艺和设备的改进来提高银的直收率和减少电解液中的中间占用,并综合介绍在生产实践过程中的应用。

脉冲金属离子等离子体推进器的等离子体生成和传播特性

综述了不同阳极结构脉冲金属离子等离子体推进器的放电特性、等离子体生成及传播特性。首先,讨论了一种带有绝缘套筒的裸阳极推进器结构。对比分析了无、有绝缘套筒的裸阳极推进器的等离子体生成及传播特性的区别。结果表明,绝缘套筒阻碍了阴极近旁带电粒子的径向运动,提高了沿绝缘套筒轴向喷射出去的等离子体的喷射性能。此外,发现采用裸阳极推进器结构放电过程中会有大量带电粒子进入阳极。其次,讨论了一种绝缘阳极推进器结构。结果表明,采用绝缘阳极结构进一步提高了沿绝缘套筒轴向喷射出去的等离子体密度。但是,与裸阳极推进器结构相比,等离子体的生成量减少。再次,讨论了一种微孔绝缘阳极推进器结构。结果表明,与裸阳极推进器结构相比,采用微孔绝缘阳极推进器结构生成的等离子体的密度峰值和传播速度峰值分别提高了12.6倍、3.9倍。最后,分别讨论了一种螺旋阳极推进器结构和一种多阳极推进器结构。结果表明,这两种推进器结构分别利用放电过程中形成的自磁场及电场有效提高了等离子体羽流的定向喷射性能。本研究可以为金属等离子体喷射性能的提高以及脉冲金属离子等离子体推进器的设计提供支持。

Fabrication and anodic polarization behavior of lead-based porous anodes in zinc electrowinning

A new type of lead-based porous anode in zinc electrowinning was prepared by negative pressure infiltration. The anodic polarization potential and corrosion rate were studied and compared with those of traditional fiat anodes （Pb-0.8%Ag） used in industry. The anode corrosion rate was determined by anode actual current density and microstructure. The results show that the anodic oxygen evolution potential decreases first and then increases with the decrease of pore diameter. The anodic potential decreases to the lowest value of 1.729 V at the pore diameter of 1.25-1.60 mm. The porous anode can decrease its actual current density and thus decrease the anodic corrosion rate. When the pore diameter is 1.60-2.00 mm, the anodic relative corrosion rate reaches the lowest value of 52.1%.

Tribological properties of nano-porous anodic aluminum oxide template

A highly ordered porous alumina template with pores of 45 nm in diameter was synthesized by a two-step electrochemical anodizing process. The influence of pore-enlargement treatment on the porous structure and tribological properties of the film was investigated, and ultrasonic impregnation technology was applied on it to form self-lubricating surface. The structure of the self-lubricating film and its tribological properties were investigated in detail. It can be concluded that the optimum time of pore-enlargement treatment is 20 min. The diameter of the pores and the surface porosity of the film are about 70 nm and 30%, respectively, while the film maintains the property of its high hardness. Under the same friction condition, the frictional coefficient of the self-lubricating film is 0. 18, much lower than that of the anodic aluminum oxide template, which is 0.52. In comparison with the lubricating surface of non-porous dense anodic aluminum oxide template, the lubricating surface fabricated by the ultrasonic impregnation method on the porous anodic aluminum oxide template keeps longer period with low friction coefficient. SEM examination shows that some C60 particles have been embedded in ultrasonic impregnation technology. the nanoholes of the anodic aluminum oxide template by the

One-step fabrication of TiO2/graphene hybrid mesoporous film with enhanced photocatalytic activity and photovoltaic performance

We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene hybrid(VTH)features unique structures with an ultra-large specific surface area of^260 m^2 g^-1 and low aggregation,giving rise to enhanced light harvesting and increased charge generation and separation efficiency.It was observed that a mesoporous film with uniform pore distribution is simultaneously obtained during the VTH growth process.When a 5.0 wt%RGO VTH film was used as the active layer in photocatalysis,the highest photocatalytic activity for degradation of methyl orange was achieved.For another,when a 0.75 wt%RGO VTH film was used as the photoanode in a dye-sensitized solar cell,the power conversion efficiency reached 7.58%,which represents an increase of 73.1%compared to a solar cell using an a photoanode of pure TiO2 synthesized by a traditional solvothermal method.It is expected that this facile method for the synthesis of TiO2/graphene hybrid mesoporous films will be useful in practical applications for preparing other metal oxide/graphene hybrids with ultra-high photocatalytic activity and photovoltaic performance.

EXPERIMENT AND RESEARCH ON DEVELOPMENT AND CHARACTERIZATIONS OF ANODIC ALUMINA MEMBR-ANE FOR USE IN HEMODIALYSIS

Objective The correlation between various formative conditions and the pore characterizationsof the anodic alumina membrane is investigated to seek the optimal conditions for the formation of anodic aluminamembrane. Methods High purity aluminum foils are used as the starting materials. The anodization is conduc-ted in three types of electrolytes, 3% sulfuric acid, 5% sulfuric acid and 2. 7% oxalic acid, respectively, with dif-ferent voltages at for 48h. The characterizations of the pore size, the effective porosity and the pore porosity areobserved and determined by scanning electron microscopy. The hydraulic conductances of the membranes are meas-ured to confirm that the pores are open and evaluate the permselectivity of the membranes. Results The experi-mental result shows that the ordered pore arrays are obtained for oxidation under our experimental conditions. Withthe increasing of the voltage, the pore size and pore porosity increased significantly (P <0.05) , while the effectiveporosity decreased significantly (P <0.05) with the same electrolyte. The pore size formed in 3% sulfuric acid or5% sulfuric acid is much smaller than in 2. 7% oxalic acid as an electrolyte. The hydraulic conductance of anodicalumina membrane that formed under our experimental condition is higher than those of the membranes are availablecurrently used in clinical. Conclusion The results suggest that the optimal conditions for the formation of anodicalumina membrane that used in hemodialysis are in 3% or 5% sulfuric acid with 12. 5V to 17. 5V at for 48h.

Antibacterial Surface Treatment of Aluminum Materials

Aluminum specimens were anodized in a sulfuric acid bath, thensilver was electrodeposited in pores of the anodized aluminum byusing alternating current. The anodized aluminum with depositedsilver was tested for its antibacterial performance. The results showthat the antibacterial rates of the specimens are above 95/100against the growth of E. coli, P. Aeruginasa, S. faecalis and S.aureus. The morphology of the silver in pores of anodized aluminum ischaracterized by transmission electron microscopy, and themicrographs indicate that silver is assembled in the form ofnanowires with a diameter of 10 nm or 25 nm. The nanowires have astructure of parallel bright stripes alternating with parallel darkstripes.

In-situ synthesized mesoporous TiO_2-B/anatase microparticles:Improved anodes for lithium ion batteries

Mesoporous TiO_2-B/anatase microparticles have been in-situ synthesized from K_2Ti_2O_5 without template.The TiO_2-B phase around the particle surface accelerates the diffusion of charges through the interface,while the anatase phase in the core maintains the capacity stability.The heterojunction interface between the main polymorph of anatase and the trace of TiO_2-B exhibits promising lithium ion battery performance.This trace of 5%(by mass) TiO_2-B determined by Raman spectra brings the first discharge capacity of this material to 247 mA · h ·g^(-1),giving 20%improvement compared to the anatase counterpart Stability testing at 1 C reveals that the capacity maintains at 171 mA·h·^(-1),which is better than 162 mA·h·g^(-1) for single phase anatase or 159 mA·h·g^(-1) for TiO_2-B.The mesoporous TiO_2-B/anatase rnicroparticles also show superior rate performance with 100 mA·h·g^(-1) at 40 C,increased by nearly 25%as compared to pure anatase.This opens a possibility of a general design route,which can be applied to other metal oxide electrode materials for rechargeable batteries and supercapacitors.

Porous CuO nanowires as the anode of rechargeable Na-ion batteries

We report the preparation of porous CuO nanowires that are composed of nanoparticles （-50 nm） via a simple decomposition of a Cu（OH）2 precursor and their application as the anode materials of rechargeable Na-ion batteries. The as-prepared porous CuO nanowires exhibit a Brunauer-Emmett-Teller （BET） surface area of 13.05 m^2.g^-1, which is six times larger than that of bulk CuO （2.16 m^2.g^-1）. The anode of porous CuO nanowires showed discharge capacities of 640 mA.h.g^-1 in the first cycle and 303 mA.h.g^-1 after 50 cycles at 50 mA.g^-1 The high capacity is attributed to porous nanostructure which facilitates fast Na-intercalation kinetics. The mechanism of electrochemical Na-storage based on conversion reactions has been studied through cyclic voltammetry, X-ray diffraction （XRD）, Raman spectroscopy, and high resolution transmission electron microscopy （HRTEM）. It is demonstrated that in the discharge process, Na＋ions first insert into CuO to form a CuⅡ1-x CuⅠ x O1-x/2solid and a Na2O matrix then CuⅡ1-xCu Ⅰ xO1-x/2 reacts with Na＋ to produce Cu2O, and finally Cu2O decompose into Cu nanoparticles enclosed in a Na2O matrix. During the charge process, Cu nanopartides are first oxidized to generate Cu2O and then converted back to CuO. This result contributes to the design and mechanistic analysis of high-performance anodes for rechargeable Na-ion batteries.

A kind of double-sided porous anodic alumina membrane fabricated with the three-step anodic oxidation method

The porous anodic alumina membranes （PAAMs） have been successfully used as templates for the fabrication of functional nano-materials due to their outstanding regularity and physicochemical properties. In this paper, a transparent double-sided anodic alumina membrane with ultra-thin aluminum substrate was fabricated with the three-step anodic oxidation method in the oxalic acid electrolyte. The characters such as the top-surface morphology, membrane thickness, and depth of nanopores of this three-layer （A1203-A1-A1203） sandwiched nano-structure were controllable through regulating the main anodic oxidation conditions, e.g., anodic oxidation time of various steps, coating remove process. The experiments data revealed that the aluminum substrate is exponential declined with the oxidation time when it was approximately reduced by a few micrometers. This new double-sided anodic alumina membrane can be used as the high-quality functional field emission materials and templates.