铝栅自对准工艺

铝栅自对准电路具有集成度高和性能价格比高等优点。本文从离子注入与合金(退火)两方面着手,研究铝栅自对准工艺。成功地研制出可与国外样品互换的铝栅自对准电路。     

热水解离子色谱法测定岩石样品中的氯和硫

研究开发了一种热水解离子色谱法测定岩石样品中的氯和硫的方法技术。所研究开发的方法具有灵敏、高效、无干扰和准确的特点。实验研究和选择了热水解离子色谱测定的最佳工作条件。用测定的方法对6个国家一级岩石地球化学标准物质GSR1－6进行了分析测定，并在研究我国东部上地壳区域元素丰度实践中测定了2000件岩石样品。测定结果表明，测定值与标准物质的标准值一致。该方法的检出限分别国；氯31×10^-6。方法的精密度（RSD，％）对氯含量水平为40×10^-6，硫酸根含量水平180×10^-6时分别为6.1%和3.0%。     

Electrically driven capillary size exclusion chromatography

Summary Electrically driven size exclusion chromatography (ED-SEC) of polystyrenes in packed capillaries using dimethylformamide as solvent is demonstrated. The efficiency and retention behaviour of polystyrenes under pressure and electro drive were investigated. Under pressure drive the plate height (H) increases steadily with increasing linear velocity (u) whereas under electro drive the H-u curves largely coincide and are very flat. At higher velocities the plate heights are about 50% smaller with electro drive than with pressure drive. Calculations show that with increasing ionic strength, the flow through the particles may increase causing a clear diminishing of the elution window.     

Corrosion effects of nuclear tracks in polymers

Usually ion tracks are studies ex-situ, i.e. after removal of the ion-irradiated sample from the evacuated irradiation vessel. The exposure to ambient air leads to degradation effects which are frequently neglected and consequently have been studied rarely. They have never been explained consistently. In this work we compile and discuss them in the frame of today's general understanding of ion tracks in polymers. It appears that some pristine polymers such as polyethylene are covered by a surface layer which is badly permeable for gaseous contaminants. Ion irradiation leads to destruction of this protective layer so that oxygen and moisture from the ambient air can easily penetrate through the ion tracks, and eventually even into the surrounding pristine material. Moisture absorption along the tracks gives rise to some faint conductivity. Oxygen uptake adds new trapping centers to the existing ones along the tracks, so that on one hand an increased dopant uptake capability is recorded, and on the other hand oxygen-sensitive mobile dopants are immobilized along the ion tracks. Photooxidation processes contribute to the fading of the optical blackening of irradiated polymers.     

Correlation between structural and optical properties of ion beam synthesized β-FeSi2 precipitates in Si

The structural and optical properties of β-FeSi₂ precipitates produced by ion beam synthesis have been investigated by transmission electron microscopy, photoluminescence (PL) analysis and near infrared transmission measurements. The PL spectrum of β-FeSi₂ precipitates in a dislocation free sample has been observed to consist of a sharp line at 1.54 μm and a weak peak at 1.46 μm. Optical transmission measurements showed a direct band gap about 0.8 eV smaller than in continuous β-FeSi₂ film. Calculation of the electronic bands of β-FeSi₂ for different values of the lattice parameters indicates that this reduction can be ascribed to band distortion provided by the lattice strain.     

High-performance liquid chromatographic determination of meropenem in rat plasma using column-switching

Summary The purpose of this study was to develop a columnswitching HPLC method for the determination of meropenem in plasma. This method showed excellent precision and accuracy with good sensitivity and speed. The total analysis time per sample was less than 20 min and the mean coefficients of variation for intra- and inter-assay were less than 4.0%. The method has been successfully applied to plasma samples from rats receiving an intraperitoneal injection of meropenem.     

Reversed-phase HPLC separation of the enantiomers of denopamine after derivatization with GITC chiral reagent

Summary A reversed-phase high-performance liquid chromatographic (HPLC) method was developed to determine the optical purity of denopamine, which is a new cardiotonic agent having an asymmetric carbon in a molecule. The enantiomers were converted to diastereomeric thiourea derivatives using 2,3,4,6-Tetra-O-acetyl--D-glucopyranosyl isothiocyanate (GITC) reagent. Separation of the enantiomers of denopamine as diastereomers was successfully achieved by reversed-phase HPLC within 10 min using an ODS column and UV detection. Derivatization of denopamine proceeded rapidly under the alkaline conditions and the ambient temperature. This method was applied to the determination of the optical purity of denopamine drug substances and those in tablets. The favorable UV absorption of the derivatives enabled the optical antipode to be determined down to the 0.2% level.     

n沟增强型InP MISFET研究

在掺Fe的<100>晶向半绝缘 InP上,用 TEOS为源的 PECVD SiO_2作为栅氧化层,以Si~+注入 S.I.InP形成源、漏区,研制成基于 InP/SiO_2界面的n沟增强型 InP MISFET.其饱和区跨导 g_m为6.4mS/mm,沟道有效电子迁移率 μ_(eff)为1400cm~2/V·S,并对 InP MISFET特性及漏电流慢漂移行为作了讨论与分析.