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采用磁控溅射技术在具有织构结构的气体扩散层(GDL)表面制备了可应用于氢氧质子交换膜燃料电池的超低Pt载量阴极催化层, 并通过SEM、 轮廓仪和XRD等测试方法表征了GDL及其载Pt后的形貌和物相, 利用XPS分析溅射Pt的化学价态, 使用电池测试台表征其电池性能. 测试结果表明, 磁控溅射法在GDL表面沉积的Pt催化层载量可控且分布均匀; 与商业GDL对比, Pt在织构GDL表面具有更大的可附着面积. 电池性能测试结果显示, 当Pt载量为0.04 mg/cm2时, 以织构GDL作基材的样品质量比功率高达26.25 kW/g Pt, 远大于商业GDL作基材时的17.76 kW/g Pt, 也大于同等Pt载量下商业Pt/C催化剂的24.00 kW/g Pt. 相似文献
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《理化检验(化学分册)》2017,(4)
提出了高效液相色谱-电雾式检测器法(HPLC-CAD)测定卡格列净中葡萄糖酸-δ-内酯(GDL)的含量。优化的色谱条件如下:Thermo Hypersil Gold Aq色谱柱(250 mm×4.6 mm,5μm),流动相为乙腈(9+1)混合溶液,流量0.5mL·min~(-1),柱温30℃,进样量10μL;电雾式检测器(CAD)的雾化温度为50℃,载气压力427.5kPa。在上述的色谱条件下,GDL的线性范围为1.05~22.5mg·L~(-1),GDL的检出限(3S/N)为0.32ng。在3个浓度水平上进行加标回收试验,测得回收率在96.2%~103%之间。供试品加标溶液和对照品溶液在室温条件下放置12h内稳定,测定值的相对标准偏差(n=7)分别为1.8%,1.3%。 相似文献
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单缝石英管原子捕集原子吸收光谱法测定了水中碲 总被引:6,自引:4,他引:2
研究了单缝石英管贫焰捕集-脉冲富焰释放原子捕集原子吸收光谱法测定碲的条件和线性范围;用X射线衍射分析得碲以Te4O11形式捕集,探讨了捕集、释放机理。测定质量浓度为20μg/L的碲(Ⅵ)时,捕集1min后测得特征质量浓度为1.76×10^-3mg/L,比常规FAAS法提高113倍,相对标准偏差为2.6%,已用于饮用水样中痕量碲的测定。 相似文献
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电热进样微波等离子体原子吸收光谱法的性能研究 总被引:2,自引:0,他引:2
本文将L形放电-吸收管与电热进样微波诱导等离子体原子吸收光谱法相结合,考察了各种实验参数对分析性能的影响.给出了利用该方法测定一系列元素的特征浓度,讨论了共存元素等因素对检测结果的影响.将本法用于实际样品分析,结果较好. 相似文献
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为了探讨原子吸收光谱法和原子发射光谱法测定工业废水中的总铬分析方法的异同,分别采用两种方法对工业废水中的总铬进行了对比分析,对样品前处理方法,方法的标准曲线、检出限、准确度、精密度、干扰及消除等进行了比较,并对两种方法的测定结果进行t检验。结果表明,两种方法具有良好的一致性。相对来说,原子发射光谱法各方面指标要优于原子吸收光谱法。 相似文献
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Romanzin C Boyé-Péronne S Gauyacq D Bénilan Y Gazeau MC Douin S 《The Journal of chemical physics》2006,125(11):114312
The A-X bands of the CH radical, produced in a 248 nm two-photon photolysis or in a supersonic jet discharge of CHBr(3), have been observed via cavity ring-down absorption spectroscopy. Bromoform is a well-known photolytic source of CH radicals, though no quantitative measurement of the CH production efficiency has yet been reported. The aim of the present work is to quantify the CH production from both photolysis and discharge of CHBr(3). In the case of photolysis, the range of pressure and laser fluences was carefully chosen to avoid postphotolysis reactions with the highly reactive CH radical. The CH production efficiency at 248 nm has been measured to be Phi=N(CH)N(CHBr(3))=(5.0+/-2.5)10(-4) for a photolysis laser fluence of 44 mJ cm(-2) per pulse corresponding to a two-photon process only. In addition, the internal energy distribution of CH(X (2)Pi) has been obtained, and thermalized population distributions have been simulated, leading to an average vibrational temperature T(vib)=1800+/-50 K and a rotational temperature T(rot)=300+/-20 K. An alternative technique for producing the CH radical has been tested using discharge-induced dissociation of CHBr(3) in a supersonic expansion. The CH product was analyzed using the same cavity ring-down spectroscopy setup. The production of CH by discharge appears to be as efficient as the photolysis technique and leads to rotationally relaxed radicals. 相似文献
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《Spectrochimica Acta Part B: Atomic Spectroscopy》2002,57(11):1727-1737
The creation and stabilization processes of an argon surface-wave-sustained discharge at atmospheric pressure have been studied by means of a power interruption technique. The analysis of the temporal behavior of the radial electric field intensity outside the plasma has permitted us to study the advance of the ionization front along the plasma column. However, the temporal evolution of the intensity of some atomic emission lines has also been analyzed during the creation process of the discharge. Some relevant results of this study are presented and discussed in terms of the ionization front and the stabilization of the electric field as well as the temporal evolution of excited level populations of the species. 相似文献
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The absolute values of the rate constants for heterogeneous recombination of chlorine atoms on the surface of aluminum and copper in the positive column of a glow discharge in Cl2 have been determined using the pulse relaxation technique. 相似文献
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Claudia González de Vega Cesar Álvarez Llamas Nerea Bordel Rosario Pereiro Alfredo Sanz-Medel 《Analytica chimica acta》2015
The analytical capabilities of a glow discharge (GD) as a secondary source for excitation/ionization of the material provided by laser ablation (LA) have been compared to conventional laser induced breakdown spectroscopy (LIBS). In LA–GD both sources can be independently adjusted to optimize the sampling process and then its subsequent excitation. This could involve a number of analytical performance advantages, such as reduced matrix dependence, greater precision and sensitivity than those encountered in LIBS. For such purpose, an ablation chamber design including two electrodes to generate the GD discharge has been built and assayed. A comparison between LIBS and LA–GD–OES has been carried out, both, under reduced argon and helium atmospheres. Different sets of samples (conducting reference materials, glass and fluorine pellets) have been used to evaluate the novel coupled technique. The LA–GD coupled system has shown to provide lower detection limits. In addition, best linear correlations between intensities and concentrations and lower matrix effects have also been found using the coupled system. Moreover, special advantages of the LA–GD–OES have also been demonstrated for the analysis of fluorine. 相似文献
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《Sensors and Actuators》1988,13(1):11-27
Transport phenomena in an amorphous silicon film deposited by a glow discharge technique have been reviewed, and many interesting applications of this material in sensors are considered. A large Seebeck effect is observed in the highly-conductive amorphous silicon film and a thermopile power sensor has been developed using this film. The large elastoresistance effect observed in the film has been investigated for possible use in strain sensors, touch sensors and real-time correlators. The light-related phenomena and their sensor applications have also been briefly reviewed. 相似文献
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The effects of BaSO4 and a lignosulphonate on the normal discharge and charge processes of a porous lead electrode have been examined by the potential-step technique. Here, BaSO4 is shown to exert a major electrochemical effect on the discharge reaction while the lignosulphate is found to increase the available active surface area of the electrode. 相似文献
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Intracavity laser absorption spectroscopy ("ICLAS") has been demonstrated as a feasible detection method for trace species in a discharge flow tube. This implementation has been used to measure the rate of the reaction between atomic hydrogen and NO to form HNO in helium carrier gas. A reaction rate constant of (4.3 +/- 0.4) x 10(-32) cm(6) molecule(-2) s(-1) at 295 K was measured for the reaction H + NO + M --> HNO + M (M = He). The pressure and concentration range enabled by ICLAS detection has allowed us to limit reactive pathways that would inhibit the formation of HNO. The sensitivity of ICLAS, coupled with the versatility of the discharge flow technique, suggests that intracavity absorption spectroscopy will be a useful technique for kinetics measurements on free radicals and other reactive species. 相似文献
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V. E. Malanichev M. V. Malashin S. I. Moshkunov V. Yu. Khomich 《High Energy Chemistry》2016,50(4):304-307
A dielectric barrier discharge plasma reactor has been designed and constructed. The space discharge regime has been implemented. The reactor operating conditions for the desired reaction have been calculated using the dissociation of water molecules as a model reaction. The operating conditions have been selected for the dissociation of water vapor via excitation of vibrational levels of the molecule by a single electron impact. 相似文献
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Detection of trace radioisotopes in soil,sediment and vegetation by glow discharge mass spectrometry
Betti M Giannarelli S Hiernaut T Rasmussen G Koch L 《Analytical and bioanalytical chemistry》1996,355(5-6):642-646
The possibility for the determination of some radioisotopes of cesium, strontium, plutonium, uranium and thorium by glow discharge mass spectrometry (GDMS) in soils, sediments and vegetations is investigated. The preparation of samples is described as a combination of the use of a conductive host matrix and a secondary cathode in order to decrease the dilution effect of the blending material for the trace level determination and to gain a stable discharge. Effects of interferences arising from the nature of the conductive host matrix and of the secondary cathode on the sensitivity of the method are discussed. The determination of (137)Cs and (90)Sr has been attempted and the results obtained were in agreement with those from other analytical techniques. Accuracy, internal and external precisions have been also evaluated. GDMS is shown to be a helpful technique for the determination of radioisotopes in environmental samples. Radioisotopes can be determined according to the matrix of the sample (e.g. grass), also in presence of isobaric interferences. However, limitations still exist on the application of GDMS. 相似文献