氧空位对多孔氧化锆光学性质的影响

以多孔氧化锆(ZrO2)材料的制备与光学性质为基础,讨论了氧空位对光学发光性能的影响及氧化锆发光性质的位形坐标图.以水热法制备的多孔ZrO2粉体具有由结晶不完整的ZrO2颗粒堆积而成的多孔结构,产物的比表面积达151.9m2·g-1.检测了样品的光吸收和光致发光(PL)性能,并用解卷积方法对样品的光致发光谱进行了分析,发现了不同于以前的结果.多孔ZrO2的主要光致发光峰位于蓝紫色光区,而经过H3PO4处理后的样品的发光峰红移至蓝绿色发光区,样品的多孔结构和磷的存在并不能使ZrO2中产生新的发光峰.分析结果显示氧空位在产物中形成一个新的能级,在发光性质中起着捕获电子形成色心而导致荧光发光的作用.     

Study by Rutherford Backscattering Spectroscopy of the Heterostructure of Lead Titanate Thin Films

A depth profile analysis of modified lead titanate thin films was performed by means of Rutherford Backscattering Spectroscopy (RBS). These films were deposited from sol-gel synthesized solutions onto platinized silicon substrates and crystallized by thermal treatments at temperatures of about 650°C. The chemistry of the solution and the thermal treatment for crystallization affect the heterostructure of the resulting films. Losses of lead and formation of substrate-film interfaces are produced during the crystallization of the films. These film characteristics determine their ferroelectric response.     

Microanalysis For Platinum and Magnesium in Body Fluids and Brain Tissue of Mice Treated with Cis-Platinum Using Graphite Filament Plasma Emission Spectroscopy

Abstract

A method has been developed for the microanalysis of platinum (0.1-500 mg/L) and magnesium (20-40 mg/L) in body fluids and brain tissue using a novel graphite filament plasma (GFP) emission source. Twenty five microliter samples of brain tissue homogenates and body fluids were analyzed without the usual preinstrumental digestion. Calibration standards were prepared in the same matrix as the samples because of the need for matrix matching. The body fluid samples were from mice which received therapeutic doses of the anticancer agent cis-diamminedichloro-platinum(II) (DDP). Platinum levels in urine were initially quite high (400-500 mg/L) due to the bolus method of administration, but lowered substantially within hours. Biphasic elimination of platinum from plasma was observed with half lives of 14 minutes and 32 hours. The equilibration of platinum between the plasma and the erthrocytes was between one and two hours. Hypermagnesia was observed in urine, plasma and whole blood during the twenty-two hour period following DDP injection. In brain tissue of mice given therapeutic doses of DDP singly or in combination with the polar solvent, maturational agent, N-methylformamide (NMF), the platinum levels were at or below the present detection limits of the instrument (0.1 mg/kg fresh tissue).     

Analysis of Borosilicate Catalysts by Inductively Coupled Plasma Atomic Emission Spectroscopy

Abstract

A method was developed for the analysis of borosilicate catalysts. Samples were prepared by fusion technique with potassium hydroxide and analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The method was applied to a borosilicate NIST SRM 93 which was analyzed for major and minor elements (aluminum, sodium, silicon and boron). Despite the presence of relatively high concentration of the potassium, no matrix interferences were observed. This method provides precision and accuracy better than ±4% and ±6%, respectively.     

Oxygen evolution: the mechanism of formation of porous anodic alumina

Abstract  Aluminium anodization behavior in ammonium sebacate solution (w = 4%) in ethylene glycol, and in several H₃PO₄-containing electrolytes, has been investigated. A new mechanism is proposed for the formation of porous anodic films. The model emphasizes the close relationship between pore generation and oxygen evolution. PO₄ ³⁻ ions incorporated in the anodic films behave as the primary source of avalanche electrons. It is the avalanche electronic current through the barrier film that causes oxygen evolution during anodization. When growth of anodic oxide and oxygen evolution occur simultaneously at the aluminium anode, cavities or pores are formed in the resulting films. Accordingly, the mechanisms of growth of barrier and porous films are not very different in nature. These findings are a decisive new step towards full understanding of the nature of anodic alumina films. Graphical abstract        

多孔氮化钛载体上铂催化剂的原子层沉积制备及其催化氧气还原性能

为有效解决铂(Pt)催化剂用于氧气还原反应(ORR)面临的催化活性及稳定性问题,本文首先合成了具有良好导电性、电化学稳定以及耐腐蚀等优点的一维多孔氮化钛(Ti N)纳米管载体材料,然后使用原子层沉积技术(ALD)在Ti N载体上沉积制备了Pt催化剂(ALD-Pt/Ti N),所得的Pt纳米颗粒尺寸均匀、高度分散且与Ti N载体之间存在着较强的相互作用。催化氧气还原活性和稳定性测试表明,所得的ALD-Pt/Ti N对ORR具有较高的催化活性,同时兼具良好的稳定性和耐久性。相比商用Pt/C,ALD-Pt/Ti N的起始电位和稳态极限电流密度与其相近,半波电位则高出了20 m V,表现出优异的电催化性能。其优良的电催化性能主要归因于ALD沉积Pt纳米颗粒的高分散性,一维多孔结构Ti N载体的高比表面积、良好导电性和抗腐蚀性能以及ALD-Pt与Ti N载体间较强的相互作用等综合影响。本工作为设计新型高催化活性、高稳定性的Pt基催化剂提供了有益借鉴。     

等离子体发射光谱法测定大白鼠脑组织中的铝

铝元素在脑中累积会损伤脑功能[1-2],据不少文献报道,阿尔茨海默氏病(A lzheimer′s d isease,简称AD)即人们统称的老年性痴呆病患者脑中的铝含量显著高于正常人[3-4]。铝在脑中含量很低,目前测定低含量铝使用较多的方法是石墨炉原子吸收法,由于铝在高温时容易与石墨管发生反应     

Plasma-catalytic Selective Reduction of NO with C2H4 in the Presence of Excess Oxygen

This paper reports observations of significant synergistic effects between dielectric barrier discharge (DBD) plasmas and Cu-ZSM-5 catalysts for C2H4 selective reduction of NOx at 250℃ in the presence of excess oxygen by using a one-stage plasma-over-catalyst (POC) reactor. With the reactant gas mixture of 530 ppm NO, 650ppm C2H4, 5.8% 02 in N2and GHSV = 12000h^-1, the pure catalytic, pure plasma-induced (discharges over fused silica pellets) and plasma-catalytic (in the POC reactor) NOx conversion are 39%, 1.5% and 79%, respectively. The in-situ optical emission spectra of the reactive systems imply some short-lived active species formed from plasma-induced and plasma-catalytic processes may be responsible to the observed synergistic effects in this one-stage POC system.     

纤维钛酸铅/纳米钛酸铅晶体复合陶瓷材料性能研究

钛酸铅（PbTiO3）在常温下属于典型的钙钛矿结构,其居里温度高达490℃,介电常数小,压电性能高,压电各向异性大,是一种优良的高温高频的压电材料,但因其轴向比c/a=1.063和矫顽场大,难于极化,在冷却过程四方至立方的相变中易出现微细裂纹,有时甚至破碎,所以制备纯相致密的PbTiO3陶瓷存在烧结上的困难,且因陶瓷本身固有的脆性,使其优良的电性能很难得到充分的开发和利用。PbTiO3的应用通常是通过掺杂改性而获得的。而掺杂改性会对其电性能产生不良的影响。如能寻找一种有效的方法,即改善其烧结特性,又不影响其电性能,而且能制得致密的PbTiO3陶瓷,则对PbTiO3的研究与应用具有重要的意义。     

低温等离子体对聚合物多孔膜的亲水化改性

综述了低温等离子体在聚合物多孔膜表面亲水化改性领域的研究与应用进展。在简要介绍等离子体技术的原理、方法的基础上,讨论了Ar、He、O2、N2、CO2、H2O、NH2和SO2等非反应性和反应性气体的等离子体表面处理,烷基醇、烷基胺、烯丙基醇和烯丙基胺等饱和及不饱和单体的等离子体沉积聚合,以及烯类单体的等离子体引发的接枝聚合等等离子体方法,对膜表面和膜孔壁的化学组成和形态结构、膜亲水性的获得及其时效性、膜水通量和蛋白质抗污染性等方面的影响。     

Plasma polymerization of fluoromethanes

Methane and fluoromethanes (CH_nF_4−n, 1 ≤ n ≤ 3) were subjected to an rf glow discharge plasma. All the fluoromethanes (including methane) polymerized in the plasma and formed thin films. The deposition rate of the fluoromethanes depended on their monomer structure: CH₂F₂, of which the F/H ratio is unity, showed the greatest deposition rate. The elimination of H and F atoms as H—F was found to be a key factor for the polymerization of fluoromethanes. The chemical composition of the polymerized film, measured with X-ray photoelectron spectroscopy and glow discharge emission spectroscopy, was also found to be strongly dependent on monomer structure. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2043–2050, 1998     

Investigation of the Crystallisation Behaviour of Lead Titanate (PT), Lead Zirconate (PZ) and Lead Zirconate Titanate (PZT) by EXAFS-Spectroscopy and X-Ray Diffraction

Two solid solutions of lead zirconium titanates PbZr _x Ti_{1 – x} O₃ (x = 0.1 and 0.35) as well as the reference compounds lead titanate and lead zirconate were prepared from zirconium and titanium n-propoxide, dissolved in 2-methoxyethanol, by sol-gel process. The amorphous products after pyrolysis of the dried gels and the crystalline phases were studied by EXAFS spectroscopy to monitor the structural changes from the amorphous oxide mixture to the crystalline ceramics after calcination. Additionally, the crystalline phases were identified by X-ray diffraction (XRD).It follows from the analysis of the EXAFS data that the local order of the amorphous phases seems to be completely different from that of the crystalline phase. There is no indication of a preformation of the local order of the perovskite structure. The analysis of our EXAFS spectra can be interpreted very consistently with the assumption that in the amorphous samples a segregation exists on molecular level and the low crystallisation temperatures are a consequence of very short diffusion paths.     

丙烯腈中铁铜等15种杂质元素的电感耦合等离子体发射光谱法测定

采用电感耦合等离子体发射光谱法同时测定了丙烯腈中的Al、B、Ca、Cd、Cr、Cu、Fe、K、Li、Mg、Mn、Na、Ti、Sr、Zn15种杂质元素；比较了HNO3和HN03-HClO4 2种消解样品的方法；结果表明，后者能使样品消解彻底，无丙烯腈残留；考察了酸度和丙烯腈残留量对测定结果的影响；酸度对测定结果无影响，丙烯腈残留对元素分析结果(除№外)有较强的抑制作用，对K测定结果影响复杂；元素的检出限为0．001～0．2mg／L，标准加入回收率为92％～112％；方法安全、简便、快速、准确。     

A Study on the Determination of Copper by Microwave Induced Plasma Atomic Emission Spectrometry (MIP-AES)

The determination of copper by MIP-AES was investigated in detail. Aqueous samples were introduced from an ultrasonic nebulizer and the solvent was removed by a desolvation device before introduction of the aerosol into the MIP. The desolvation system consisted of a condenser associated with a concentrated H2SO4 absorption cell. Various experimental conditions and interferences from easily ionised elements (EIEs) were also studied and some practical samples were analyzed.     

火焰原子吸收与火焰原子发射光谱法测定正常人尿中铝的比较

采用N2O-C2H2火焰原子吸收与火焰原子发射光谱法同时测定了正常人尿中铝。研究了40种干扰离子和24种有机物在N2O-C2H2火焰中对铝吸收和发射信号的影响。试验表明，40种干扰离子和24种有机物对给吸收和发射信号的正负影响基本上是一致的．但程度有所不同。原子吸收和发射光谱法对应的检出限分别为0．26mg·L-1和0．08mg·L-1，7次测定的RSD分别为1．9％和1．7％，加入1.0mg·L-1铝的回收率分别为92.4％～105．1％和96．1％～106．3％。     

ICP-AES法测定高温合金中5种非金属元素

本文研究了快速测定高温合金中5种非金属元素(As、B、P、Se、Si)的分析方法,以满足高温合金行业对非金属元素检测的需求。利用王水和高氯酸对高温合金进行酸溶解,并系统研究了基体元素和共存元素对分析元素谱线的光谱干扰情况,同时进行了分析谱线的选择。5种非金属元素的检出限在5.5 ～ 11.9 ug/ml,5次数据的相对标准偏差(RSD,n=5)为0.9 % ～ 7 %,各元素的回收率在96 % ～ 102 %之间,该方法适用于高温合金中非金属元素的测定。     

电感耦合等离子体原子发射光谱(ICP-AES)法测定高温合金中5种非金属元素

研究了快速测定高温合金中5种非金属元素(As,B,P,Se,Si)的分析方法,以满足高温合金行业对非金属元素检测的需求。利用王水、氢氟酸和酒石酸对高温合金进行酸溶解,系统研究了基体元素和共存元素对分析元素谱线的光谱干扰情况,同时进行了分析谱线的选择。5种非金属元素的检出限在5.0~12.0μg/mL,5次数据的相对标准偏差(RSD,n=5)为1.1%~4.0%,各元素的加标回收率在96%~102%,方法适用于高温合金中非金属元素的测定。     

Improving the Catalytic Efficiency of NiFe-LDH/ATO by Air Plasma Treatment for Oxygen Evolution Reaction

Developing efficient catalysts toward the oxygen evolution reaction(OER)is important for water splitting and rechargeable metal-air batteries.Although NiFe oxides are considered as potentially applicable catalysts in the alkaline media,there are still a limited numbers of researches working on membrane electrode assembly(MEA)fed with pure water due to their poor electrical conductivity.In this work,antimony doped tin oxide(ATO)has been employed as conductive supports where NiFe layered double hydroxide uniformly dispersed[named NiFe-LDH(layered double hydroxide)/ATO].The catalysts have been synthesized by a one-step co-precipitation method,and then NiFe-LDH/ATO-air plasma was obtained through mild air plasma treatment.According to XPS analysis,binding energies of Ni2p and Fe2p were shifted negatively.Moreover,a new signal of low oxygen coordination appeared on O1s spectrum after air plasma treatment.These XPS results indicated that oxygen vacancies(Ov)were generated after air plasma treatment.Electrochemical measurement indicated that the vacancy-rich NiFe-LDH/ATO-air plasma exhibited better performance than NiFe-LDH/ATO not only in 1 mol/L KOH solutions but also in an alkaline polymer electrolyte water electrolyzer(APEWE)fed with deionized water.This work provides a feasible way to design practical catalysts used in electrochemical energy conversion systems by choosing corrosion resistance supports and defect engineering.     

电感耦合等离子体原子发射光谱(ICP-AES)法测定再生锌原料中铜、铅、铁、铟、镉、砷、钙、铝

采用硝酸、盐酸、氢氟酸(氟化氢铵)、高氯酸分解样品,电感耦合等离子体原子发射光谱法测定了再生锌原料中铜、铅、铁、铟、镉、砷、钙、铝的量。其测定范围:ω(Cu):0.01%～0.60%;ω(Pb):0.10%～5.00%;ω(Fe):0.10%～5.00%;ω(In):0.0100%～0.200%;ω(Cd):0.010%～3.00%;ω(As):0.10%～2.00%;ω(Ca):0.10%～10.00%;ω(Al):0.10%～4.00%。各元素的加标回收率为93%～113%。方法准确、快速、可靠,适用于再生锌原料中铜、铅、铁、铟、镉、砷、钙、铝量的同时测定。     

Influence of Gadolinium on Carbon Arc Plasma and Formation of Fullerenes and Nanotubes

Gadolinium-doped (0.8 at.%) graphite anodes were dc arced to produce different nanocarbons. Emission spectroscopy was performed to determine the temperature and column density distributions of C₂ (a³_u=0) in the arc plasma under 13.3 and 60 kPa pressures in helium atmosphere. The solid products were analyzed by UV-VIS, TOF MS, HR SEM, and TEM techniques. The influence of metal catalyst on the formation of C₆₀, and endohedral fullerenes, and carbon nanotubes is discussed.