射频反应溅射CdIn2O4膜制备过程中氧浓度对光学性质的影响

采用射频反应溅射方法在Ａｒ＋Ｏ２气氛中制备了ＣｄＩｎ２Ｏ４薄膜，报道了在没氧浓度下该膜的透射率和随波长的变化关系。发现氧浓度越高，膜透射率赵低，而消光系数１、折射率相应地越大。对这些结果从ＣＩＯ膜的晶格常数、载流子浓度等角度进行了理论分析。     

Cdln2O4和Cd2SnO4薄膜X—光电子能谱研究

研究了在Ａｒ－Ｏ２混合气氛中从Ｃｄ－Ｉｎ和Ｃｄ－Ｓｎ合金靶射频反应溅射而的ＣｄＩｎ２Ｏ４和Ｃｄ２ＳｎＯ４膜的Ｘ－光电子能谱。实验结果表明了粉末Ｃｄ，Ｉｎ，Ｓｎ，ＳｎＯ２，Ｉｎ２Ｏ３和ＣｄＩｎ２Ｏ４，Ｃｄ２ＳｎＯ４膜的Ｃｄ，Ｉｎ，Ｓｎ３Ｄ３／２和３ｄ５／２ＸＰＳ峰值位置的形状的区别，并讨论了Ｏ１ｓ。ＸＰＳ峰随氧浓度的变化。当氧浓度增加时，Ｏ１ｓ分为两个峰。     

CdIn_2O_4和Cd_2SnO_4薄膜X－光电子能谱研究

研究了在Ａｒ＋Ｏ２混合气氛中从Ｃｄ－Ｉｎ和Ｏｄ－Ｓｎ合金靶射频反应溅射而成的ＣｄＩｎ２Ｏ４和Ｃｄ２ＳｎＯ４膜的Ｘ－光电子能谱。实验结果表明了粉末Ｃｄ、Ｉｎ、Ｓｎ、ＳｎＯ２、Ｉｎ２Ｏ３和ＣｄＩｎ２Ｏ４、Ｃｄ２ＳｎＯ４膜的Ｃｄ、Ｉｎ、Ｓｎ３ｄ３／２和３ｄ５／２ＸＰＳ峰值位置和形状的区别，并讨论了Ｏ１ｓＸＰＳ峰随氧浓度的变化。当氧浓度增加时，Ｏ１ｓ分为两个峰。     

EGR与富氧进气控制柴油机排放的机理探讨

通过试验研究，考察了废气再循环加富氧进气同时控制ＮＯＸ和碳烟排放的可行性。试验中通过逐步增加ＣＯ２及Ｏ２流量，查明了进气成份变化对ＮＯＸ，碳烟，ＣＯ，ＨＣ等有害排放物以及有效燃油消耗率ｂｃ，平均有效压力ｐｃ，滞燃期，绝热指数的影响，然后用ＫＩＶＡ程序对燃烧火焰温度和ＮＯ浓度进行了模拟计算。     

在SiO2和Si3N4膜上用RTCVD法沉积多晶硅薄膜的研究

报道了在ＳｉＯ２和Ｓｉ３Ｎ４膜上用ＲＴＣＶＤ法直接沉积多晶硅薄膜的实验结果,在这两种薄膜上制备出了具有柱状晶粒的多晶硅薄膜,发现两者在薄膜的结构和结晶取向上有很大不同,用ＲＴＣＶＤ法在ＳｉＯ２膜上沉积的多晶硅膜,晶粒较大,晶粒间的空隙也较大,晶粒的择优取向为（１１１）,在Ｓｉ３Ｎ４膜上沉积的多晶硅薄膜,晶粒尺寸较小,晶粒致密,晶粒间苯无空隙,晶粒的择优取向为（１００）。     

氧化钨薄膜电致变色状态下物相组份及表面形貌变化的研究

通过对直流磁控溅射方法得到ＷＯｘ膜层的电化学和光学性能测试，以及ＸＰＤ和ＳＴＭ的物相，形貌分析，发现该ＷＯｘ膜层具有良好的电致变色性能，原始沉积态ＷＯｘ膜层为非晶态，其着退色状态仍在非晶特性，而晶ＷＯｘ膜层在着色态和退色态之间发生物相组份的可逆变化，且表面形貌有很大差异。     

汽油载重车排放净化研究

采用试验方法，研究载重车汽油机在使用过程中，由于气缸磨损和水套冷却状况的变化造成尾气排放中的ＨＣ和ＣＯ排放量增加，采用引入旁通空气和控制各气缸混合气空燃比的措施后，致使运行的载重其汽油机的ＨＣ和ＣＯ排放得到很好的控制。     

柴油机燃用柴油—甲醇—水复合乳化燃料的研究

本观察了３２例非何杰金淋巴瘤（ＮＨＬ）患红细胞铜锌超氧化物歧化酶（ＲＢＣ·Ｃｕ·Ｚｎ·ＳＯＤ），血清脂质过氧化物（ＬＰＯ）和维生素Ｅ（ＶＥ）值的变化，结果表明ＮＨＬ患ＲＢＣ·Ｃｕ·Ｚｎ·ＳＯＤ活力和ＶＥ水平明显降低（Ｐ＜０．０５及Ｐ＜０．０１），ＬＰＯ值明显增高（Ｐ＜０．０１）。对其中１３例患进行动态观察，除合并白血病的２例治疗无效外，其余１１例治疗后均获缓解，其ＲＢＣ·Ｃｕ·Ｚｎ·ＳＯＤ     

石灰石脱硫对流化床中N2O排放的影响

在鼓泡流化床装置及固定床反应器上研究了床温、Ｃａ／Ｓ值对Ｎ２Ｏ、ＮＯｘ排放浓度的影响，ＳＯ２浓度与Ｎ２Ｏ、ＮＯｘ浓度之间的关系以及石灰石对Ｎ２Ｏ的催化分解作用，并对Ｎ２Ｏ及ＮＯｘ浓度变化机理进行了讨论。     

用光纤燃烧传感器测量汽油机的燃烧时间参数的研究

本文介绍了一个光纤燃烧传感器及ＯＭＡ４光多通道分析仪组成的测量系统，用以测量汽油机燃烧火焰光谱。光谱分析结果再次证实了燃烧火焰中ＣＨ（４３１．５ｎｍ），Ｃ２（５１６．５ｎｍ），Ｈ２Ｏ（５８９ｎｍ）等自由基的特征光谱同Ｃ粒子的热辐射连续光谱叠加在一起，构成了火焰光谱。根据光谱曲线中Ｈ２Ｏ光强峰值变化，可以确定汽油机燃烧过程中重要的时间参数：着火延迟期和燃烧持续期。由于汽油机燃烧循环变动大，与单色仪和ＢＯＸＣＡＲ积分平均器组成的测量系统相比，光纤燃烧传感器＋ＯＭＡ４用光多通道分析仪系统测量汽油机燃烧火焰光谱，测量精度高，工作效率高。     

Angle-dependent XPS analysis of silicon nitride film deposited on screen-printed crystalline silicon solar cell

In this work silicon nitride (Si₃N₄) film was deposited as an antireflection coating (ARC) on crystalline silicon solar cell (cell?A) using plasma-enhanced chemical vapor deposition (PECVD). Two solar cells XA and XB of approximately equal area were diced from cell#A and characterized by angle-dependent X-ray photoelectron spectroscopy (XPS). The XPS profiling shows the presence of silicon (Si), nitrogen (N), carbon (C) and oxygen (O) in the Si₃N₄ film. The presence of C and O indicates that organic substances, involved in processing steps were not released completely from the surface and may diffuse in Si₃N₄ ARC during deposition. The XPS spectra corresponding to Si2p, N1s, C1s and O1s were recorded at angles 0° (normal to the surface), 30° and 45°, as angle increases spectra becomes more surface sensitive. Peak positions in Si2p and N1s spectra explain the oxygen contamination in the Si₃N₄ film. The shift in the peak positions of C1s and O1s as angle increases from 0° to 45° explains the surface contamination of carbon and oxygen. The atomic composition of elements Si, N, C and O show more carbon, oxygen concentration and smaller N/Si ratio than stoichiometry, i.e. Si₃N₄ in cell XB. However, cell XA not only show better photovoltaic performance in terms of parameters open-circuit voltage (V_oc), short-circuit current density (J_sc), fill factor (FF) and efficiency (η) but also have more uniform texturization and regular pyramids on the surface as revealed by scanning electron microscopy (SEM). The presence of higher concentration of impurities (carbon and oxygen), non-uniformity in texturization and in the Si₃N₄ film as well could be responsible for less satisfactory photovoltaic performance of cell XB.     

Copper oxide thin films prepared by chemical vapor deposition from copper dipivaloylmethanate

Polycrystalline copper oxide thin films are prepared at a reaction temperature above 280°C by an atmospheric-pressure chemical vapor deposition method. The source materials were copper dipivaloylmethanate and oxygen. It has been shown from the experiment that two kinds of films, i.e., Cu₂O and CuO are grown by controlling oxygen partial pressure. A series of characterizations on the film quality by scanning electron microscope, X-ray photoelectron spectroscopy, X-ray diffraction and Fourier transform infrared spectrometer has been made, and the performance of solar thermal conversion are also identified on the produced films. Results show that the well-crystallized CuO film has lower infrared transmittances due to the scatterings of light through the optically anisotropic monoclinic structure.     

Poly-silicon films with low impurity concentration made by hot wire chemical vapour deposition

Analyses of various impurities (O, C, W, Fe, Ni and Cr) in the poly-Si material (both in layers as well as in cell configurations) made by HWCVD have been carried out to judge the quality of this material for application in devices. SIMS analysis showed that the oxygen concentration in the bulk of a poly-Si film made at a low hydrogen dilution (Poly2) is 3×10¹⁸ cm⁻³ and the oxygen content drops to this value within a depth of only 50 nm from the surface. On the other hand, a poly-Si film made at a high hydrogen dilution (Poly1) has a high and homogeneous oxygen content of more than 2×10²¹ cm⁻³. However, in a double-layer structure (Poly2 on top of Poly1), the oxygen content of the bottom layer (Poly1) is significantly smaller than the bare Poly1 film, though this oxygen concentration is still much higher than that in the top Poly2 layer. We attribute this behaviour to the structural difference between these two films (2000 cm⁻¹ Si–H IR vibration in low-dilution material and 2100 cm⁻¹ vibration in the high-dilution material). We propose that the oxygen penetration in Poly1 occurs by two processes: (1) oxygen incorporation during growth: (2) post-deposition oxygen intrusion. The first process occurs at a low deposition rate and is dependent on the type of growth process. The second process is due to the intrusion of water vapour into the film through the voids, which increases the conductivity of the film depending on the amount of intrusion. We have shown that our device quality compact poly-Si : H (Poly2) resists oxygen incorporation even when deposited in an oxygen-rich atmosphere.     

Three-dimensional numerical simulation of oxygen isotope transport in lanthanum strontium manganese - Yttria-stabilized zirconia cathode of solid oxide fuel cell

Distribution of oxygen isotope ¹⁸O concentration which was labeled in lanthanum strontium manganese (LSM) – yttria-stabilized zirconia (YSZ) cathode of a solid oxide fuel cell (SOFC) is predicted through numerical simulations using a three-dimensional microstructure which was reconstructed by a focused ion beam-scanning electron microscopy (FIB-SEM). The electrochemical reaction under the SOFC operation is first numerically simulated, then the unsteady ¹⁸O transport is simulated by coupling self-diffusion by concentration gradient, migration by the electrochemical potential field, and electrochemical reaction at the triple phase boundaries. Predicted results were compared with the measured ¹⁸O concentration by a secondary ion mass spectrometry taken at the intermediate plane of the reconstructed 3D microstructure, which showed qualitative consistency between them. Thus, from the direct correlation of the electrochemical reaction and ¹⁸O concentration in an actual electrode microstructure, influence of electrochemical reaction was discussed. The present approach provides useful information for the interpretation of the oxygen labeling experiment results, which can cultivate better understanding of the electrochemical reaction mechanism in the SOFC electrodes.     

Ethanol flame structure investigated by molecular beam mass spectrometry

The oxidation of ethanol was studied in low-pressure, premixed flat flames using molecular beam mass spectrometry (MBMS) in combination with electron impact ionization (EI) and resonance-enhanced multiphoton ionization (REMPI). Flame temperature profiles were measured by laser-induced fluorescence (LIF) of seeded NO. Two ethanol/oxygen/argon flames with stoichiometries of ?=1.00 and ?=2.57 were investigated at 50 mbar by EI-MBMS. Profiles of a variety of stable and radical species were measured as a function of height above the burner. The benzene profile in the fuel-rich ethanol flame was obtained by REMPI-MBMS. The same technique was used to determine the dependence of the benzene concentration on the ethanol/propene ratio in low-pressure flames with blended fuels (propene/ethanol/oxygen/argon). The C/O ratio of all blends was kept constant at C/O=0.773 or C/O=0.600. Ethanol addition ranged from 0 to 15% for flames with C/O=0.773, and from 0 to 100% for flames with C/O=0.600. In both data sets, a decrease of the benzene concentration with increasing ethanol percentage was observed. Qualitative information on some other aromatic species with higher mass was also obtained.     

Evidence of different oxygen states during thermal coloration of tungsten oxide

In this study, we report on the thermal reduction of tungsten oxide studied with in situ photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). XPS measurements of the O1s core level of the annealed oxide film in vacuum show the appearance of a second state displaced in 1.1 eV towards higher binding energy. We propose that the shifted component is due to the difference in the charge state of oxygen anions and results from oxygen that is not bonded to metal. Simultaneous increase of the O¹⁶ ion yield measured with ToF-SIMS suggests that this higher binding energy component is related to atomic oxygen that is released from the oxide but remains in film.     

稀释气体组分和浓度对柴油喷雾燃烧特征影响

通过一台高温、高压可视化定容燃烧弹,采用高速摄像技术研究了不同稀释气体(Ar、N2和CO2)在10%~40%的氧体积分数范围内对柴油喷雾着火和火焰发展过程的影响;采用羟基自发光成像和双色法研究了低氧体积分数下稀释气体组分(Ar和N2)对火焰发展特征和碳烟分布的影响.结果表明:随氧体积分数增加,柴油机喷雾火焰自发光亮度增强,火焰宽度减小,碳烟初始形成位置向喷雾上游迁移.氧体积分数为30%、稀释气体为CO2时,火焰头部出现剧烈波动.在低氧体积分数下,稀释气体为N2时的火焰自发光亮度远弱于稀释气体为Ar的情况,在气体成分为10%O2+90%N2的情况下,在燃烧初期会观察到微弱的蓝色化学发光.使用Ar替代N2作为稀释气体后火焰浮起长度显著缩短,火焰温度上升,火焰中游内部的碳烟浓区分布更广.相比于N2,极端低氧体积分数下使用Ar作为稀释气体能够有效提升柴油喷雾火焰的着火稳定性.     

Oxygen reduction on platinum electrode coated with Nafion

The kinetics of the reduction of oxygen on platinum covered by a Nafion^® film in sulfuric acid (0.5 M) has been studied in order to determine to what extent the solid polymer electrolyte modifies this reaction. As electrode we used a rotating electrode which is particularly well adapted to the measurement of the permeability D_fC_f (product of the diffusion coefficient and of the oxygen concentration in the film) of oxygen in the Nafion^® film. This product is of the order of 6×10⁻¹² M cm⁻¹ s⁻¹ whatever the state of division of the platinum, and is of the same order of magnitude as the permeability D_sC_s of oxygen in the adjacent sulfuric acid solution. It is shown, moreover, that the oxygen concentration in the film is very high, about five times that in the solution.     

Identification of active sites in CO2 activation on MgO supported Ni cluster

In this work, initial activation mechanism of CO₂ over MgO supported Ni catalysts has been systematically studied through the periodic DFT calculations. In addition, the role of metal cluster, interface and support for CO₂ activation is investigated and the active site is identified. CO₂ is most favored to be activated on the interface instead of neither Ni cluster nor MgO support. The effective energy for this process is around 0.67 eV, and the dissociation of CO₂ (0.62 eV) is the rate-determining step, since it requires much higher energy than that of the CO₂ adsorption process (0.05 eV). Thus, the interface between metal cluster and support plays a key role for C=O bond activation. Moreover, CO1 is preferred to be adsorbed on the Ni cluster, while the O1 is likely to bind on Mg atom of support. To illustrate the adsorption behavior of CO₂ at different sites, the Mulliken atomic charge and electron density difference have been calculated. It was found that the total amount of electron gain for CO₂ binding at different sites follows the order of Interface (−0.03 e) < MgO support (−0.05 e) < Ni cluster (−0.07 e), and effective energy barrier rises linearly with the increase of electron gain of CO₂ binding at different sites. In addition, electron gain of oxygen atom O1 and oxygen atom O2 of CO₂ is the same for Ni cluster and MgO support, however, the electron gain of O1 and O2 is different for Interface. The difference of electron gain for two oxygen atoms shows the electron unbalance of CO₂ molecule, which is in favor of C=O activation. This study could shed some light on understanding the active sites of CO₂ thermal-catalytic activation over MgO supported Ni catalysts, and is helpful to elucidate the reaction on an atomic level.