HT-7超导托卡马克第一壁硼化膜扫描电镜(SEM)分析

ＨＴ－７超导托卡马克采用原位气相沉积法在其内真空室第一壁沉积一层含硼膜。在与第一壁同样径向位置处放了几个不锈钢和石墨样品，以取样第一壁上沉积的鲜膜和经过等离子体轰击的轰击膜，并对它们进行扫描电镜分析。扫描电镜图反映了硼化膜的形貌和等离子体对第一壁的多种作用，从而充分地证实了膜对第一壁的保护作用。

HL—1M装置硼化膜的研究

ＨＬ－１Ｍ装置采用Ｃ２Ｂ１０Ｈ１２蒸汽等离子体增强沉积技术对第一壁进行了原位硼化，在第一壁表面上形成一层半透明、非晶ａ－Ｂ／Ｃ：Ｈ膜。在单电极、１．２Ａ／７５０Ｖ放电参数下，平均沉积速率为１１０ｎｍ／ｈ，膜厚不均匀度为８４％，Ｂ／Ｃ＝０．６－２．０，Ｂ－Ｃ的结合能为９７－９９ｅＶ，与Ｂ／Ｃ值有关。膜层中有２０－３０％的硼是以Ｂ－Ｃ的形式存在，７０－８０％碳是以ａ－Ｃ：Ｈ形式存在。

Effects of boric acid on microstructure and corrosion resistance of boric/sulfuric acid anodic film on 7050 aluminum alloy

The microstructure and corrosion resistance of different boric/sulfuric acid anodic（BSAA） films on 7050 aluminum alloy were studied by atomic force microscopy（AFM）,electrochemical impedance spectroscopy（EIS） and scanning Kelvin probe（SKP）.The results show that boric acid does not change the structure of barrier layer of anodic film,but will significantly affect the structure of porous layer,consequently affect the corrosion resistance of anodic film.As the content of boric acid in electrolyte increases from 0 to 8 g/L,the resistance of porous layer（Rp） of BSAA film increases,the capacitance of porous layer（CPEp） decreases,the surface potential moves positively,the pore size lessens,and the corrosion resistance improves.However,the Rp,CPEp and surface potential will change towards opposite direction when the content of boric acid is over 8 g/L.

复合溶胶凝胶法制备TiB_2可湿性阴极涂层

针对铝工业阴极和阳极碳电极以及侧壁耐蚀导电二硼化钛陶瓷涂层技术,研究用非有机溶剂湿化学陶瓷清洁制造技术,替代沥青粘结工艺。通过氧化铝胶体中的纳米粒子,分散清洁二硼化钛,形成均匀陶瓷悬浮涂料,经刷涂或喷涂形成TiB2涂层。对二硼化钛与工业铝电解体系熔体、气相的化学侵蚀性进行了理论计算,分析了炭基TiB2涂层的耐蚀性、捕获钠的机理。用SEM分析了二硼化钛涂层断面,二硼化钛在氧化铝胶粒的分散下,迁移、渗入多孔的碳基底,在热处理条件下,与基底间形成很强的化学键合,可形成微米至数毫米厚、无龟裂的涂层。涂层的电性能检测结果表明,浆料中氧化铝胶体含量为 10%Wt时电阻率较低,电阻率随烧结温度升高而降低。

A Diamond Electrochemical Cleaning Technique for Organic Contaminants on Silicon Wafer Surfaces

Peroxodiphosphate anion （a powerful oxidant） can be formed in a special water-based cleaning agent through an electrochemical reaction on boron-doped diamond electrodes. This electrochemical reaction was applied during the oxidation,decomposition, and removal of organic contaminations on a silicon wafer surface, and it was used as the first step in the diamond electrochemical cleaning technique （DECT）. The cleaning effects of DECT were compared with the RCA cleaning technique, including the silicon surface chemical composition that was observed with X-ray photoelectron spectroscopy and the morphology observed with atomic force microscopy. The measurement results show that the silicon surface cleaned by DECT has slightly less organic residue and lower micro-roughness,so the new technique is more effective than the RCA cleaning technique.

Biological,antibacterial activities and electrochemical behavior of borided commercially pure titanium in BSA-containing PBS

The effects of boride coating on the bioactivity, antibacterial activity, and electrochemical behavior of commercially pure titanium(CP-Ti) in phosphate buffer solution(PBS) with bovine serum albumin(BSA) were studied. The grazing incidence X-ray diffraction(GIXRD) pattern confirmed the formation of a Ti B/Ti B2 coating via boriding process. Scanning electron microscopy(SEM) observation indicated that the Ti B2 cross-linked particles covered the Ti B whiskers. Water contact angle measurements revealed that boriding led to the formation of a surface with intermediate water affinity. Potentiodynamic polarization(PDP) assays demonstrated that the Ti B/Ti B2 coating had acceptable passivation behavior in BSA-containing PBS. Electrochemical impedance spectroscopy(EIS) measurements revealed that the passivation behavior of the CP-Ti and the borided samples was improved by increasing exposure time. Based on the Mott-Schottky(M-S) tests, it was realized that the charge carriers of passive films of both samples decreased with increasing exposure time in BSA-containing PBS. The bioactivity test results in a simulated body fluid showed that the Ti B/Ti B2 coating switched the CP-Ti from bioinert to bioactive material. Finally, the antibacterial activity test of the Ti B/Ti B2 coating against Escherichia coli and Staphylococcus aureus indicated 99% antibacterial activity.

Theoretical Calculation on Optimum Si-doping Content in Boron Carbide Thin Film

The theoretical expression of the relationship between optimumdoping content and crystal structure is presented as well as thepreparation methods. By using this expression, the optimum dopingcontent of silicon-coped boron carbide thin film is calculated. Thequantitative calculation value is consistent with the experimentalresults. This theoretical expression is also appropriate to resolvethe optimum doping content for Other electric materials.

Electrochemical oxidation of reactive brilliant orange X-GN dye on boron-doped diamond anode

In this study,the electrochemical oxidation of reactive brilliant orange X-GN dye with a boron-doped diamond(BDD)anode was investigated.The BDD electrodes were deposited on the niobium(Nb)substrates by the hot filament chemical vapor deposition method.The effects of processing parameters,such as film thickness,current density,supporting electrolyte concentration,initial solution pH,solution temperature,and initial dye concentration,were evaluated following the variation in the degradation efficiency.The microstructure and the electrochemical property of BDD were characterized by scanning electron microscopy,Raman spectroscopy,and electrochemical workstation;and the degradation of X-GN was estimated using UV-Vis spectrophotometry.Further,the results indicated that the film thickness of BDD had a significant impact on the electrolysis of X-GN.After 3 h of treatment,100%color and 63.2%total organic carbon removal was achieved under optimized experimental conditions:current density of 100 mA/cm2,supporting electrolyte concentration of 0.05 mol/L,initial solution pH 3.08,and solution temperature of 60°C.

Effects of h-BN content on properties of Ni-Cr/h-BN composite

Ni-Cr/h-BN self-lubricating composities were prepared by powder metallurgy (P/M) method.The effects of hexagonal boron nitride (h-BN) content on the mechanical and tribological properties of the Ni-Cr/h-BN composites were investigated.The corresponding frictional models were established to analyze the formation of the lubricant h-BN films on the surfaces of the Ni-Cr/h-BN composites.The results show that,when the content of h-BN increases from 5% to 15% (mass fraction),the bending strength of the Ni-Cr/h-BN composite decreases from 96.670 MPa to 17.319 MPa,and the hardness (HB) decreases from 33 to 14.The friction coefficient of the Ni-Cr/h-BN composite decreases firstly from 0.385 to 0.216,and then increases to 0.284,while the wear rate decreases firstly from 4.14×10-9 kg/(N·m) to 1.35×10-9 kg/(N·m),then increases to 2.36×10-9 kg/(N·m).The best comprehensive mechanical and tribological properties can be obtained between 10% and 12% h-BN addition.

Electrochemical treatment of wastewater containing chlorophenols using boron-doped diamond film electrodes

The electrochemical treatment of wastewater containing chlorophenols （2-monochlorophenol, 4-monochlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol） was carried out experimentally with synthetic boron-d0ped diamond （BDD） thin film electrodes. Current vs time curves under different cell voltages were measured. Removal rate of COD, instant current efficiency （ICE） and energy consumption were investigated under different current densities. The influence of supporting media is reported, which plays an important role in determining the global oxidation rate. The oxidative chloride is stronger than peroxodisulphate. The electrochemical characteristics of boron-doped diamond electrodes were investigated in comparison with active coating Ti substrate anode （ACT）. The experimental results show that BDD is markedly superior to ACT due to its different absorption properties.

Surface Functionalization of Microporous Polypropylene Membrane with Polyols for Removal of Boron Acid from Aqueous Solution

Affinity membranes are fabricated for boric acid removal by the surface functionalization of microporous polypropylene membrane(MPPM)with lactose-based polyols.The affinity is based on specific complexation between boric acid and saccharide polyols.A photoinduced grafting-chemical reaction sequence was used to prepare these affinity membranes.Poly(2-aminoethyl methacrylate hydrochloride)[poly(AEMA)]was grafted on the surfaces of MPPM by UV-induced graft polymerization.Grafting in the membrane pores was visualized by dying the cross-section of poly(AEMA)-grafted MPPM with fluorescein disodium and imaging with confocal laser scanning microscopy.It is concluded that lactose ligands can be covalently immobilized on the external surface and in the pores by the subsequent coupling of poly(AEMA)with lactobionic acid(LA).Physical and chemical properties of the affinity membranes were characterized by field emission scanning electron microscopy and Fourier Transform Infrared/Attenuated Total Refraction spectroscopy(FT-IR/ATR).3-Aminophenyl boric acid(3-APBA)was removed from aqueous solution by a single piece of lactose-functionalized MPPM in a dynamic filtration system.The results show that the 3-APBA removal reaches an optimal efficiency(39.5%)under the alkaline condition(pH9.1),which can be improved by increasing the immobilization density of LA.Regeneration of these affinity membranes can be easily realized through acid-base washing because the complexation of boric acid and saccharide polyol is reversible.

失效物理

HT-7超导托卡马克采用原位气相沉积法在其内真空室第一壁沉积一层含硼膜。在与第一壁同样径向位置处放了几个不锈钢和石墨样品,以取样第一壁上沉积的鲜膜和经过等离子体轰击的轰击膜,并对它们进行扫描电镜分析。扫描电镜图反映了硼化膜的形貌和等离子体对第一壁的多种作用,从而充分地证实了膜对第一壁的保护作用。

Fabrication of large area hexagonal boron nitride thin films for bendable capacitors

Highly reliable and bendable dielectrics are desired in flexible or bendable electronic devices for future applications. Hexagonal boron nitride （h-BN） can be used as bendable dielectric due to its wide band gap. Here, we fabricate high quality h-BN films with controllable thickness by a low pressure chemical vapor deposition method. We demonstrate a parallel-plate capacitor using h-BN film as the dielectric. The h-BN capacitors are reliable with a high breakdown field strength of -9.0 MV/cm. Tunneling current across the h-BN film is inversely exponential to the thickness of dielectric, which makes the capacitance drop significantly. The h-BN capacitor shows a best specific capacitance of 6.8 F/cm^2, which is one order of magnitude higher than the calculated value.

Growth and low-energy electron microscopy characteri- zation of monolayer hexagonal boron nitride on epitaxial cobalt

Low-energy electron microscopy （LEEM） has been used to study the structure, initial growth orientation, growth progression, and the number of layers of atomically thin hexagonal boron nitride （h-BN） films. The h-BN films are grown on heteroepitaxial Co using chemical vapor deposition （CVD） at low pressure. Our findings from LEEM studies include the growth of monolayer film having two, oppositely oriented, triangular BN domains commensurate with the Co lattice. The growth of h-BN appears to be self-limiting at a monolayer, with thicker domains only appearing in patches, presumably initiated between domain boundaries. Reflectivity measurements of the thicker h-BN films show oscillations resulting from the resonant electron transmission through quantized electronic states of the h-BN films, with the number of minima scaling up with the number of h-BN layers. First principles density functional theory （DFT） calculations show that the positions of oscillations are related to the electronic band structure of h-BN.

Research on the piezoelectric response of cubic and he- xagonal boron nitride films

Boron nitride （BN） films for high-frequency surface acoustic wave （SAW） devices are deposited on Ti/AI/Si（111） wafers by radio frequency （RF） magnetron sputtering. The structure of BN films is investigated by Fourier transform infrared （FrlR） spectroscopy and X-ray diffraction （XRD） spectra, and the surface morphology and piezoelectric properties of BN films are characterized by atomic force microscopy （AFM）. The results show that when the flow ratio of nitrogen and argon is 2：18, the cubic BN （c-BN） film is deposited with high purity and c-axis orientation, and when the flow ratio of nitrogen and argon is 4：20, the hexagonal BN （h-BN） film is deposited with high c-axis orientation. Both particles are uniform and compact, and the roughnesses are 1.5 nm and 2.29 nm, respectively. The h-BN films have better piezoelectric response and distribu- tion than the c-BN films.