还原熔融法同时测定铜铬合金中的氧氮含量

样品经过表面预处理，选择合适的样品质量及仪器测试条件，应用TC-30还原熔融法同时测定铜铬合金中的氧氮。氧氮的回收率为97．2％～101．1%，相对标准偏差小于3．5%。     

同时测定铀铌合金中微量氧和氮

探讨了测定铀铌合金中的微量氧和氮的影响因素,建立了氧氮同时测定的新方法,测定铀铌合金中氧范围为50－1000ug.g^-1,氮范围为10－500ug.g^-1。     

超细氮碳化物中吸附氧和化合氧的测定

用跟踪式程序升温、红外检测和微机解卷技术，测定氮碳化物超细粉的吸附氧和化合氧，探讨了超细Ｓｉ３Ｎ４，ＡＩＮ，ＴｉＣＮ和ＳｉＣ中不同状态氧量与其制备方法，颗粒度及放置时间的关系。     

用化学除氧技术以1,2—二溴乙烷作重原子微扰剂—β—环糊精诱导室…

本文首次将亚硫酸钠化学除氧技术应用于β－环糊精诱导室温磷光（β－ＣＤ－ＲＴＰ）法中，除氧简便快速（１￣１．５ｍｉｎ），测定了痕量二氢苊、Ｗｕ、菲、７，８－苯并喹啉。１，２－二溴乙烷作重原子微扰剂，其用量减少到每１０ｍＬ中５μＬ，体系基本澄清，ｐＨ≈６．８，分析特性优于通氮除氧技术所得结果。     

基于氦离子化气相色谱法测定微量氧、氮的影响因素

探讨氦离子化气相色谱法测定样品中微量氧、氮含量的影响因素。采用控制变量法,对色谱柱温度、进样流量、进样管道环境及极化电压等因素对微量氧、氮测定结果的影响进行讨论和分析。结果表明,当色谱柱温度为25~45℃时,色谱柱对氧、氮吸附量最小;当进样流量不小于70 mL/min时,微量氧、氮测定结果受外界干扰最小;当极化电压为80~160 V时,氧、氮具有最佳的响应值;初次测定样品中微量氧、氮含量时,需使进样管道表面吸附的氧、氮处于饱和状态,以便获得理想的测定结果。讨论的结果可为氦离子化气相色谱法测定相关样品中微量氧、氮含量时提供技术参考。     

高温钛合金粉中氧氮的同时测定

氧氮的存在对合金材料性能影响很大 ,控制合金中氧氮杂质的含量十分重要。金属中的氧、氮主要以化合态或固溶态存在[1 ] 。而粉状的金属合金具有较大表面积 ,易对氧、氮产生特性吸附并引起氧化 ,因而其氧氮的赋存状态比较复杂。要完全、同时从金属合金粉中抽取出氧氮很困难 ,必须满足一系列热力学和动力学条件[2 ] 。本文采用镍囊包样和助熔 ,脉冲惰气熔融法同时测定高温钛合金粉样中的氧氮含量 ,9次平行测定氧的相对标准偏差为 1 6% ,氮的相对标准偏差为 2 .8%。1　实验部分1 .1　试剂及仪器镍囊 :将镍箔用乙醚清洗净后烘干 ,做成一边开口…     

用气相色谱仪测定变压器油中气体

本文采用多柱自动切换气相色谱仪和真空全脱气装置对变压器和互感器用油中的气体进行了系统的分析，除可测定油中的氢、甲烷、乙炔、乙烯、乙烷、二氧化碳和一氧化碳等气体外，还可根据不同需要测定氮、氧以及Ｃ３和Ｃ４烃的含量。本方法已用于诊断变压器和互感器内部变化及故障。     

脉冲加热-红外吸收/热导法同时测定碳化硅粉末和纤维中氧和氮

采用脉冲加热-红外吸收、热导法,通过选择合适的助熔剂、确定分析功率和称样量,建立了同时测定碳化硅粉末和碳化硅纤维中的氧和氮含量的方法。经优化后,称取碳化硅粉末20～100 mg,碳化硅纤维7～10 mg,将粉末或纤维放入0.5 g镍囊中,加1 g镍篮后,在分析功率5.5 k W下进行测定。采用碳化硅和氮化硅标准物质测得氧和氮的校准曲线;碳化硅粉末中氧和氮检出限0.0135%和0.0018%,回收率95.8%和95.6%,相对标准偏差(RSD)均小于2%;碳化硅纤维中氧和氮检出限0.0386%和0.0051%,回收率104.2%和99.7%,RSD均小于5%。本方法同时适用于碳化硅纤维和粉末中氧和氮含量的检测。     

化学除氧技术在环糊精诱导室温磷光法中的应用：（Ⅱ）2—溴乙醇作？…

以２－溴乙醇作重原子微扰剂，用亚硫酸钠化学除氧技术，建立了β－环糊精诱导室温磷光法（β－ＣＤ－ＲＴＰ）测定痕量二氢苊，芴，菲，７，８－苯并喹啉的方法。该法除氧简便快速，体系澄清。     

化学除氧技术在环糊精诱导室温磷光法中的应用(Ⅱ)2-溴乙醇作重原子微扰剂β-环糊精诱导室温磷光法测定四种痕量多环芳烃

以．２－溴乙醇作重原子微扰剂，用亚硫酸钠化学除氧技术，建立了β－环糊精诱导室温磷光法（β－ＣＤ－ＲＴＰ）测定痕量二氢苊、芴、菲、７，８－苯并喹啉的方法．该法除氧简便快速，体系澄清     

Optimizing Strength and Ductility of Titanium Alloys by Oxygen: Review and Prospect

The traditional strengthening elements of titanium alloys include Al, Mo, V, etc., however, the high cost and toxicity of these elements put a limit on their further applications for biomaterials. Ubiquitous light elements such as oxygen are hopeful replacement due to high biocompatibility. It is recognized that the oxygen enhances the strength but pays the price of brittleness, thus the amount of oxygen is constrained. However, recent study results indicated that excess oxygen can keep high ductility together with high strength of titanium. This paper reviews the influence and the mechanism of oxygen on the strength and ductility of titanium alloys, and provides a new perspective for the strengthening method of titanium alloys.     

Thermodynamics of oxygen solutions in titanium-containing Fe–Co melts

Performed for the first time, the thermodynamic analysis of oxygen solutions in titanium-containing Fe–Co melts showed that the deoxidizing power of titanium with increasing cobalt content of the melt first decreases, reaches a minimum at a cobalt content of 20%, and then increases. The titanium contents [%Ti]* at equilibrium points between the oxide phases TiO₂, Ti₃O₅, and Ti₂O₃ were determined. The curves of the oxygen solubility in titanium-containing iron–cobalt melts pass through a minimum, which shifts toward lower titanium contents with increasing cobalt content of the melt. Further alloying with titanium leads to an increase in the oxygen concentration of the melt so that the higher cobalt content of the melt, the steeper the increase in the oxygen content after the minimum as titanium is added to the melt.     

Effect of exposure to light on the chemical properties of the surface of titania particles obtained by dispersing a rutile crystal in air

It has been found that during exposure to UV light, which is absorbed by titanium dioxide obtained by dispersing a rutile crystal in air, water effectively interacts with the lattice oxygen of the metal oxide with the subsequent release of oxygen into the gas phase in the dark and with the reduction of titanium dioxide.     

DBD Plasma Treatment of Titanium in O2, N2 and Air

Dielectric Barrier Discharge plasma treatment of a titanium metal foil in oxygen, nitrogen and air under atmospheric conditions is investigated employing X-Ray Photoelectron Spectroscopy (XPS). We investigated three different reference samples and compare the results with a large number of studies on the XPS analysis of titanium compounds containing oxygen and nitrogen. The plasma treatment in all three different process gases leads to the formation of titanium dioxide films, while rather small nitrogen fractions are found after nitrogen and air plasma treatments. This finding is explained basing on plasma chemistry insight from the literature.     

Hybride process,microfiltration-electroperoxidation,for water treatment

Cross-flow microfiltration through a 0.8 μm inorganic tubular membrane was enhanced by coupling with a two electrode electrolysis cell producing hydrogen peroxide at high rate, without adding any chemical, by use of carbon felt cathode and dimensional stabilised anode (titanium coated with RuO₂). Anodic oxygen and transfer from atmosphere supplied the required oxygen. The current should be maintained under a maximum value to avoid peroxide reduction. This electrochemical process, called electroperoxidation, upgraded the water quality by removing contaminants that limit mass transport through the membrane, i.e. turbidity, dissolved organic carbon (DOC) and microorganisms. Transient filtration was adjusted to an internal clogging model whose coefficient decreased at the same rate as DOC. The microfiltration steady state flux was multiplied by a factor proportional to the peroxide concentration introduced in the filtration loop. The induced resistance decreased simultaneously with chemical oxygen demand and 254 nm absorbance. Steady state fluxes 2.5 times higher than without treatment were experimentally obtained.     

Binding energy of 2p3/2 electrons of titanium in titanium oxide layers synthesized by molecular lamination method

A variation has been found in the binding energy of the 2p_3/2 electrons of titanium in titanium oxide layers obtained by the molecular lamination method. With increasing number of synthesized monolayers, as a result of the decrease in the relative quantity of oxygen atoms in the film and the relative content of hydroxyl groups in this quantity of oxygen atoms, the effective charge on the titanium atom is lowered in comparison with a monolayer film, as manifested in a decrease of the binding energy of the titanium 2p_3/2 electrons, down to the value characteristic for titanium in bulk titanium oxide.Lensovet Leningrad Technological Institute, Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 6, pp. 722–726. November–December, 1991. Original article submitted January 22, 1990.     

Analyse du titane et de ses alliages par spectrométrie d'émission dans l'ultraviolet-vide

The large ultraviolet spectrograph for analysis in vacuum (VUV spectrograph) developed by ONERA and described in a previous article, has been used for multielements quantitative analysis: in pure titanium, concentrations of oxygen, nitrogen, hydrogen and carbon have been determined as well as silicon and iron impurities; in titanium-based alloys, addition metals at high concentration, Al, V, Mo, Zr, Si, have also been determined simultaneously with the gaseous elements and impurities. The analytical lines located between 200 and 2600 Å and corresponding to highly ionized atoms (II to VI) have been selected. The stability of the equipment has been tested and the repeatability of results has been investigated. This new analytical technique allows the study of various surface phenomena such as the variations in oxygen, nitrogen and carbon concentrations with a resolution in depth of a few microns. The method allows it to envisage the quantitative analysis of surface phenomena on metal films with a thickness below one micron.     

Influence of Synthesis Conditions on the Electrokinetic Characteristics of Titanium–Oxygen Nanostructures

Influence of synthesis conditions of titanium–oxygen nanostructures on their electrochemical behavior is studied. The nanostructures were prepared by molecular layer-by-layer deposition from the gaseous phase onto the substrates (silicon oxides titanium oxide, and silicon covered with oxide film). It is found that the deposition of a titanium–oxygen nanolayer onto the titanium oxide does not change the position of isoelectric point and the value of electrokinetic potential. Deposition of the titanium–oxygen nanostructure on the initial, as well as on the thermally and chemically modified silicon and silicon oxide substrates at various temperatures yields samples whose isoelectric points lie between the values for the substrate and deposited titanium oxide.     

Anodic stripping voltammetric determination of titanium(IV) using a carbon paste electrode modified with cetyltrimethylammonium bromide

A method is described for the voltammetric determination of titanium(IV) using a carbon paste electrode modified in situ with cetyltrimethylammonium bromide. The cationic micellar surfactant adsorbs onto the electrode particularly at negative potentials, simultaneously preconcentrating titanium(IV) as the oxalate complex with reduction to titanium(III). Anodic stripping voltammetry exploiting reoxidation can be used for the determination of trace levels of titanium(IV). Linearity between current and concentration exists between 5 and 160 mug l(-1) Ti(IV) (preconcentration time 2 min). The limit of detection (calculated as 3sigma) is 0.1 mug l(-1), with a preconcentration time of 10 min.     

A hybrid density functional study on the electron and hole trap states in anatase titanium dioxide

We present a theoretical study on electron and hole trap states in the bulk and (001) surface of anatase titanium dioxide using screened hybrid density functional calculations. In both the bulk and surface, calculations suggest that the neutral and ionized oxygen vacancies are possible electron traps. The doubly ionized oxygen vacancy is the most stable in the bulk, and is a candidate for a shallow donor in colorless anatase crystals. The hole trap states are localized at oxygen anions in both the bulk and surface. The self-trapped electron centered at a titanium cation cannot be produced in the bulk, but can be formed at the surface. The electron trap level at the surface oxygen vacancy is consistent with observations by photoelectron spectroscopy. The optical absorptions and luminescence in UV-irradiated anatase nanoparticles are found to come from the surface self-trapped hole and the surface oxygen vacancy.