12－硅钨酸与γ－Al_2O_3载体表面的相互作用

研究了不同溶剂中ＳｉＷ１２在γ－Ａｌ２Ｏ３表面的吸附和溶脱规律，以ＩＲ，ＸＲＤ以及酸催化模型探针反应对吸附于γ－Ａｌ２Ｏ３表面的ＳｉＷ１２的存在形态和酸性进行了表征．尽管ＳｉＷ１２碱降解稳定性在常见杂多酸中最强，但由水溶液中吸附在γ－Ａｌ２Ｏ３表面的ＳｉＷ１２仍有一部分被该载体的碱性所降解．此外，在γ－Ａｌ２Ｏ３表面上ＳｉＷ１２质子的活动性大大减弱，其阴离子的热稳定性也明显降低．可以认为，ＳｉＷ１２的质子和Ｋｅｇｇｉｎ阴离子与γ－Ａｌ２Ｏ３表面均有直接相互作用．     

氧化还原功能纤维的研究──含醇胺基纤维的制备及其与Au~（3＋）的氧化还原吸附反应

用二乙醇胺、乙醇胺及三乙醇胺与反应性氯甲基化纤维进行胺化反应，得到的功能纤维Ⅰ、Ⅱ和Ⅲ的含氮量分别为２．２６、２．７１和１．８６ｍｍｏ１／ｇ．吸附实验结果表明，纤维Ⅰ、Ⅱ和Ⅲ对Ａｕ~（３＋）的最大吸附量分别为５５０、６２０、４０９ｍｇ／ｇ，且能将部分吸附态Ａｕ~（３＋）还原成单质金．通过元素分析、红外光谱、核磁共振谱以及光电子能谱证实纤维中与氮原子相邻的羟基碳原子先被氧化成了羰基而氮原子未被氧化．     

Imaging fibrinogen adsorbed on noble metal surfaces with scanning tunneling microscopy: correlation of images with electron spectroscopy for chemical analysis, secondary ion mass spectrometry, and radiolabeling studies

Fibrinogen adsorption on gold and platinum surfaces has been studied with electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectrometry (SIMS), ¹²⁵I labeling, and scanning tunneling microscopy (STM). Stable images of single molecules have been obtained, but are rare. ESCA, SIMS, and labeling studies confirm that absorbed fibrinogen is present on samples at monolayer and submonolayer coverages even when STM images show only a bare substrate. Imaging is more reproducible at high coverages at which single molecules cannot be resolved. Possible explanations for the failure of STM to observe adsorbed fibrinogen molecules are discussed.     

Two dimensional TLC determination of PAH in diluted automobile exhaust gases

A method is described for the determination of polycyclic aromatic hydrocarbons (PAH) in the diluted exhaust gas of diesel vehicles. Sampling is done by drawing off proportional streams from the dilution tunnel. The particulates deposited on filters are sublimed, and the sublimate is purified and prefractionated on silica gel. Further separation and quantitative determination of the PAH is performed by two dimensional TLC in conjunction with In situ fluorescence spectrometry. Results of theoretical considerations and experimental data on the distribution of the emitted PAH between particulate matter and the corresponding gas phase in diluted exhaust are presented. A modified Langmuir adsorption model is used to explain the effects of dilution ratio and sample temperature in the dilution tunnel. Comparison of the emission values for PAH obtained from diluted and undiluted exhaust shows good agreement. Furthermore, the PAH contents of the exhaust gas of several diesel-engined cars are also compared for various driving cycles.     

搅拌下吸附富集时不可逆过程峰电流方程式

线性变势吸附伏安法是一种简便的痕量分析方法。本文讨论了此方法中不可逆过程的峰电流方程式,并对其作了验证。仪器与试剂 83-2.5型多阶自动新极谱仪(各档灵敏度已校正),LZ_3-100型函数记录仪,Metrohm E410型悬汞电极,所用试剂同文献[1]。实验方法在含0.1mol/dm~3NH_3/NH_4Cl,1×10~(-4)mol/dm~3丁二肟,pH=9.2的Co(Ⅱ)溶液中用氮气除氧并搅拌。由于配合物的稳定常数很大(β=10~(17)),可以认为Co(Ⅱ)A_2的浓度等于Co(Ⅱ)的浓度。由于电势负于-1.20V时Co(Ⅱ)A_2在电极上不吸附,因此先将电极置于-1.5V,一当从悬汞电极中旋出新的汞滴,立即将电势恒定于-0.8V,富集一定时间,然后关闭搅拌器,30秒后,电势以100mV/s的速度向负方向扫描至-1.3V,同时     

The multi-species surface-micelle model for surfactant adsorption and the BET equations

Based on the multi-species surface micelle model, the adsorption isotherm equations are derived which are identical to the BET equations. Some of the surfactant adsorption phenomena are explained on this basis.     

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.     

Atomic Absorption Spectrophotometric Determination of Copper(II) after Adsorption of its Oxinate on Microcrystalline Naphthalene

A New Atomic Absorption Spectrophotometric Procedure Has Been Developed For The Microdetermination Of Copper(Ii) As Its Oxinate By Its Adsorption On Micro-Crystalline Naphthalene And Dissolution In 1 N Nitric Acid. Copper(Ii) Oxinate Is Quantitatively Adsorbed In The PH Range Of 3.2–10.1 And Trace Amounts Of Copper Can Be Determined. The Effect Of Variables Such As Reagent And Naphthalene, Shaking Time, Digestion Time, And Diverse Ions Are Studied. The Proposed Method Has Been Applied To The Determination Of Copper In Standard Reference Material (Zinc Alloy), And Metallic Zinc And Lead.