水中矿物元素的ICP-MS分析

用ICP－MS对地下水、地表水和饮用水中的矿物元素进行了分析测定，实验证明用ICP－MS可以同时测定地下水，地表水和饮用水中矿物元素；该法灵敏度、精密度和准确度都能满足有关标准的要求，具有多元素同时分析，样品前处理简单，干扰少，测定快速，省事省力等优点。     

Electron kinetics of collision dominated r.f. bulk plasma in CO: The role of second-kind collisions

Electron energy distribution functions (EEDF) and related properties in the bulk region of the rf CO plasma at the reduced rf field frequency /p₀=×10⁷ sec^–1 torr^–1 have been calculated by solving the time-dependent spatially homogeneous Boltzmann equation in the presence of second-kind collisions and have been interpreted on a microphysical basis. The results show that second-kind collisions (vibrational and electronic) strongly affect the temporal evolution of EEDF, of the mean energy, and of the mean collision frequencies for vibrational and electronic excitation processes, as well as for ionization. In particular, second-kind collisions in the CO rf bulk plasma strongly decrease the modulation of the mean ionization frequency during its periodical alteration in the rf field. Furthermore, the effect of second-kind collisions on an approximate determination of the time-averaged EEDF in the rf bulk plasma using the so-called effective-field appriximation has been estimated.     

一种新型毛细管电泳—电感耦合等离子体光谱法接口装置

毛细管电泳是一种高效、简便的分离方法，已被用于生物、环境及临床等试样的分离及分析[1]．检测技术在毛细管电泳中占有重要的地位，目前，在柱紫外可见及荧光检测是两种广为接受的检测方法，但其检测灵敏度仅为10－5～10－6mol／L[2]．电感耦合等离子体光谱（ICP－AES／MS）是一种灵敏的元素选择性的分析方法，已被广泛地用于各种试样中元素分析．近年来，该方法作为色谱及毛细管电泳的检测器，被用于元素的形态分析[3]．在毛细管电泳（CE）与ICP光谱连用技术中，挑战性的工作是设计一种能把CE与ICP相连的接口．目前已有几种接口…     

脉冲电晕环境中13X分子筛对NO分解作用的研究

在常温、常压下，利用脉冲电晕放电产生冷等离子体，使一氧化氮发生分解，直接生成氮气和氧气，用四极杆质谱仪在线测量反应过程中反应物和生成物的变化。在自行研制的实验台上，考察了13X分子筛在不同的脉冲电晕放电条件下，表现出来的不同特性及其对反应转化率的影响。在30 ℃～430 ℃、流量375 mL/min～1 333 mL/min，分析了该反应过程中13X分子筛对转化率的促进作用。在同一脉冲放电条件下，控制13X分子筛的温度为200 ℃，转化率从30 ℃时的1.2%上升到19.7%；转化率最高可以达到35.9%。并对反应过程中13X分子筛的吸附特性做了初步探讨。     

Surface modification of low density polyethylene (LDPE) film by low pressure O2 plasma treatment

In this work, low pressure glow discharge O₂ plasma has been used to increase wettability in a LDPE film in order to improve adhesion properties and make it useful for technical applications. Surface energy values have been estimated using contact angle measurements for different exposure times and different test liquids. In addition, plasma-treated samples have been subjected to an aging process to determine the durability of the plasma treatment. Characterization of the surface changes due to the plasma treatment has been carried out by means of Fourier transformed infrared spectroscopy (FTIR) to determine the presence of polar species such as carbonyl, carboxyl and hydroxyl groups. In addition to this, atomic force microscopy (AFM) analysis has been used to evaluate changes in surface morphology and roughness. Furthermore, and considering the semicrystalline nature of the LDPE film, a calorimetric study using differential scanning calorimetry (DSC) has been carried out to determine changes in crystallinity and degradation temperatures induced by the plasma treatment. The results show that low pressure O₂ plasma improves wettability in LDPE films and no significant changes can be observed at longer exposure times. Nevertheless, we can observe that short exposure times to low pressure O₂ plasma promote the formation of some polar species on the exposed surface and longer exposure times cause slight abrasion on LDPE films as observed by the little increase in surface roughness.     

Nitriding of titanium with plasma jet under reduced pressure

The nitriding of titanium with argon-nitrogen (3%) and argon-nitrogen (3%)-hydrogen (2%) plasma jets at pressures of 190 torr was studied. The reaction kinetics obeyed mainly a parabolic law. The parabolic kinetic constants were 10^–10–10^–8 g² cm^–4 s^–1, which were 2–3 orders of magnitude larger than those in R.F. discharges. From emission spectroscopy, nitrogen atoms in the excited states were observed. The nitrogen atoms can promote the nitriding reaction. The effect of the addition of hydrogen to nitrogen is also briefly discussed.     

超高效液相色谱-三重四极杆质谱法测定血浆和尿液中马桑亭和马桑宁

建立了超高效液相色谱-三重四极杆质谱联用技术测定血浆和尿液中马桑中毒标志物马桑亭和马桑宁的方法。血浆和尿液样品经固相支持液液萃取法提取净化后，溶于15%（v/v）甲醇水溶液中，以Cortecs C₁₈色谱柱（100 mm×2.1 mm，1.6 μm）作为分析柱进行分离，电喷雾负离子多反应监测（MRM）模式下检测，以氟苯尼考作为内标物，基质工作曲线内标法定量。血浆和尿液中马桑亭和马桑宁的平均加标回收率为86.2%~110%，相对标准偏差为5.1%~14.6%（n=6），血浆中马桑亭和马桑宁的检出限（S/N=3）分别为0.01 μg/L和0.1 μg/L，尿液中马桑亭和马桑宁的检出限分别为0.03 μg/L和0.3 μg/L。本法简单、灵敏、准确，可用于血浆和尿液中马桑亭和马桑宁的中毒检测。     

Reduction of Chemical Reactions in Nitrogen and Nitrogen–Hydrogen Plasma Jets Flowing into Atmospheric Air

The large number of possible chemical reactions represents a severe burdenfor modeling of even relatively simple plasma systems. Reduced sets ofchemical reactions have been obtained for numerical simulations of nitrogenand nitrogen-hydrogen plasma jets flowing into an atmospheric airenvironment. The important or active reactions are determined based on asimplified reduction method. A reaction is considered active if it leadsto higher sensitivities than a specified cutoff sensitivity of 1%. Theactive reactions exert a significant influence on main plasma parameters,such as velocity, temperature, and species concentrations. The sensitivityanalysis for the specified systems shows that two NO reactions, known asZel'dovich reactions (N₂+ONO+N andNO+OO₂+N),⁽¹⁾ are both active in a nitrogenplasma jet. On the other hand, the latter is not active and may be omittedin a nitrogen–hydrogen plasma jet. A nitrogen–hydrogen plasmajet requires contribution of two active charge exchange reactions:N₂+N⁺N⁺ ₂+N andN+H+N+ +H, while only the former is needed in a nitrogen plasmajet. The dissociation reactions are all active in both plasma jets, exceptthe dissociation of OH.     

Manipulating the surface properties of polyacrylamide with nitrogen plasma

Polyacrylamide (PAL) was physically adsorbed onto a hydroxylated silicon surface to form a uniform PAL film and the up-top PAL thin film was treated by nitrogen (N₂) plasma for surface modification. The atomic composition of the modified surface of the PAL film adsorbed on silicon substrate was analyzed with Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The surface energy of PAL film was calculated from the data of contact angle of three-probe liquid. The FTIR results show an increase of peak intensity at 1214 cm⁻¹ (NH₂ stretch vibration) after the nitrogen plasma treatment, which confirms that the nitrogen was grafted to the PAL surface in the process of N₂-plasma treatment. The XPS results show that the ratio of relative intensity of N1s to O1s increases with increasing the plasma treatment time, which further affirms the formation of the amine groups on the PAL surface after the nitrogen plasma treatment. The surface tension increases with increasing the plasma grafting time. However, the surface energy decreases rapidly at the early stage when stored in air and approaches to an equilibrium value. It suggests that some physically-adsorbed ions and alkyl radicals on PAL surface can rapidly lose their activities. The increase of the surface tension of the plasma treated PLA films is due to the amine groups covalently grafted to PAL surface.     

The Mutual Conversion of CO2 and CO in Dielectric Barrier Discharge (DBD)

Non-equilibrium plasma, which was engendered by dielectric barrier discharge (DBD) was used to analyze the mutual conversion between CO₂ and CO. The results showed that the conversion ratio of CO increased monotonously with the increasing voltage. But CO₂ was not so. Its conversion ratio reached maximum when the voltage was 3600 V in Ar system. It also showed that the existence of water molecules was more advanageous for the conversion of CO to CO₂ in Air system than in oxygen system, and the conversion ratio could reach 75.8% when the relative humidity was 100%. We also discussed the energy yield and energy efficiency, and the result was that high voltage and high concentration of reactant was disadvantageous for energy utilization.