In situ FTIR diagnostics of the radio-frequency plasma decomposition of N2O

The decomposition of N₂O in a 13.56-MHz parallel-plate system was studied usingin situ Fourier transform infrared (FTIR) spectroscopy. Areas of two infrared absorption bands of N₂O recorded at 8 cm^–1 resolution were used to estimate relative gas-phase dissociation as a function of rf power and flow rate at 500 mT. Flow rate was found to strongly affect band areas over the range of powers investigated (10–90 W). The effect of rf power on band areas diminished above 40 W, probably due to poor plasma confinement. Distortion of the band shapes by the plasma permitted rotational temperatures to be estimated. Rotational temperature increased essentially linearly with power at constant flow rate, reaching 450 K at 80 W, but was independent of flow rate at constant power. Rotational temperatures were also found to depend on the temperature of the electrodes, which were heated by plasma exposure. No infrared-active product species were observed even under batch conditions where all N₂O was irreversibly dissociated. This lack of detectable products and a 50% pressure rise observed in a batch study suggest that N₂ and O₂ are the primary stable discharge products.     

Modification of polysulfone membranes 4. Ammonia plasma treatment

The effect of NH₃ and NH₃/Ar plasma on ultrafiltration polysulfone membranes have been studied. Results of contact angle, FTIR-ATR and X-ray photoelectron spectroscopy experiments clearly showed that both plasmas introduced hydrophilic, nitrogen- and oxygen-containing moieties on the polymer surface and that NH₃/Ar plasma was more efficient. That plasma was also more aggressive--signs of strong etching could be seen on the SEM pictures. Redeposition of etched material seemed to take place inside the pores. On the contrary, ammonia plasma was soft and caused cleaning the surface and pores enlargement. Performance of ammonia plasma modified membranes was greatly improved and independent on solution pH. The last observation proved amphoteric character of the surface. NH₃/Ar plasma treatment gave membranes of acidic surface and filtration indices not so good as for ammonia plasma.     

Quantitative Comparison Between Vacuum-Ultraviolet Irradiation and Remote Hydrogen Plasma Treatment of Hydrocarbon Polymers

The photon flux of vacuum ultraviolet (VUV) and ultraviolet (UV) radiation of a hydrogen plasma with and without a MgF₂window was recorded by fluorescence measurements of sodium salicylate layers. After the compensation of the MgF₂absorption by increasing the input power into the plasma source, a comparison between afterglow hydrogen plasma and VUV treatments was made. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) were treated either with VUV radiation or with remote hydrogen plasma and mass loss and CH absorption loss were measured by a quartz crystal microbalance and by infrared reflection absorption spectroscopy, respectively. In the case of PE the effects of both treatments were found to be very similar white for PP slight differences were observed. For the actual set of experimental conditions, the radiation component is largely responsible for the efficiency of the plasma treatment. VUV and remote hydrogen plasma treatments of PS showed only a negligible loss of mass and CH absorption.     

高效液相色谱-电感耦合等离子体发射光谱联用的瞬时信号采集和处理软件及实际应用

本文对高效液相色谱-电感耦合等离子体原子发射光谱联用技术进行了研究.对所用ICAP-9000型等离子体原子发射光谱仪的控制采样程序进行了部分修改,采集的数据通过异步串行通讯方式由AppleⅡ微机传送至IBM PC286机进行处理。发展的瞬时信号采集程序能满足HPLC的检测要求,并将这一联用技术成功的用于砷的形态分析.     

Laser-Induced Fluorescence (LIF) Probe for <Emphasis Type="Italic">In-situ</Emphasis> Nitric Oxide Concentration Measurement in a Non-thermal Pulsed Corona Discharge Plasma Reactor

Laser-induced fluorescence (LIF) is an effective in-situ probe for NO concentrations below 300 ppm in a non-thermal plasma reactor. A new method has been developed to measure in-situ NO concentration in the reactor discharge region using a long-time—on the order of seconds—averaged fluorescence detection. This method, for quantifying NO concentration in a nonthermal plasma reactor, is simpler than a short-time—on the order of nanoseconds—fluorescence detection. For accurate measurement based on the new method, the LIF intensity must be close to the corona-induced fluorescence (CIF) intensity; the CIF intensity serves as a guide in selecting the LIF intensity. We find that a kinetic model proposed earlier works for two-tube reactors and represents the NO concentration in the middle of the reactor, which verifies the assumption of gas plug flow.     

反相离子对高效液相色谱法测定母粉及母液中的杀鼠新

用反相离子对高效液相色谱法测定了杀鼠新母粉及母液中有效成份含量。采用Partisil-10ODS色谱柱，以甲醇：离子对溶液＝80：20（体积比）为流动相，离子对溶液为0.005mol/L四丁基铵磷酸盐（pH为7.5)的缓冲溶液，测定波长285nm。方法在0.025-0.15g/L范围内有很好的线性关系。杀鼠新母粉和母液的相对标准偏差分别为1.24%、0.77%(n=7)，回收率分别为：母粉,97.7%-99.8%；母液，98.5%-100.4%。     

Simultaneous multichannel mass-specific detection for high-performance liquid chromatography using an array detector sector-field mass spectrometer

The use of a separation step, such as liquid chromatography, prior to inductively coupled plasma mass spectrometry (ICP–MS) has become a common tool for highly selective and sensitive analyses. This type of coupling has several benefits including the ability to perform speciation analysis or to remove isobaric interferences. Several limitations of conventional instruments result from the necessity to scan or pulse the mass spectrometer to obtain a complete mass spectrum. When the instrument is operated in such a non-continuous manner, duty cycle is reduced, resulting in poorer absolute limits of detection. Additionally, with scanning instruments, spectral skew can be introduced into the measurement, limiting quantitation accuracy. To address these shortcomings, a high-performance liquid chromatograph has been coupled to an ICP–MS capable of continuous sample introduction and simultaneous multimass detection. These features have been realized with a novel detector array, the focal plane camera. Instrument performance has been tested for both speciation analysis and for the elimination of isobaric interferences. Absolute limits of detection in the sub picogram to tens of picograms regime are obtainable, while the added mass dimension introduced by simultaneous detection dramatically increases chromatographic peak capacity.     

锂辉石—石灰石烧结中煤粉代替重油作燃料的研究和实践

目前世界锂工业原料以锂辉石为主。我国锂辉石储量居世界首位，主要分布于新疆、四川、湖南等地，其中又以四川的储量占全国第一。锂的主要基础化合物ＬｉＯＨＨ２Ｏ系用锂辉石－石灰石烧结法而得，烧结燃料是影响ＬｉＯＨＨ２Ｏ产品价格的重要因素之一。过去国内外均采用...     

Fundamental aspect and behavior of saturated fluorocarbons in glow discharge in absence of potential source of hydrogen

The glow discharge of a series of saturated fluorocarbons, C_nF_2n+2 (n = 1, 2, 4, 6, and 8), was studied with glass substrates which do not contain any hydrogen. It was found that the deposition rate was a function of the F/C ratio of the starting fluorocarbons. That is, fluorocarbons with higher F/C ratio, such as CF₄ and C₂F₆, hardly polymerized, while fluorocarbons with lower F/C ratio, such as C₈F₁₈, polymerized as well as C₂F₄. After plasma exposure, the surface of glass substrate was characterized by measurements of water contact angle, water droplet rolling-off angle, and ESCA. Although all saturated fluorocarbon plasmas could alter the surface more hydrophobic than before, the deposited materials from fluorocarbons with higher F/C were not stable. Also, in plasmas with high F/C fluorocarbons, i.e., CF₄ and C₂F₆, sputtering of the electrode material was observed. © 1992 John Wiley & Sons, Inc.     

电感耦合等离子发射光谱法测定渣油中铁、镍、钙、镁、钠、钒金属元素

用电感耦合等离子发射光谱法（ICP-AES）测定渣油中金属元素铁、镍、钙、镁、钠、钒，考察了不同的酸浓度对分析结果的影响和共存元素间的相互干扰，进行了加标回收率和精密度试验。