Adsorption of H2S or SO2 on an activated carbon cloth modified by ammonia treatment

The aim of this research is to investigate how ammonia treatment of the surface can influence the activity of a viscose-based activated carbon cloth (ACC) for the oxidative retention of H₂S and SO₂ in humid air at 25 °C. Surface basic nitrogen groups were introduced either by treatment with ammonia/air at 300 °C or with ammonia/steam at 800 °C. The pore structure of the samples so prepared was examined by adsorption measurements. Changes in the surface chemistry were assessed by X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and temperature programmed desorption (TPD). The change of ACC activity could not be merely attributed to surface nitrogen groups but to other changes in the support. Ammonia/steam treatment improved ACC performance the most, not only by introducing nitrogen surface groups, but also by extending the microporosity and by modifying the distribution of surface oxygen groups. Successive adsorption-regeneration cycles showed important differences between oxidative retention of H₂S and SO₂ and the subsequent catalyst/support regeneration process.     

Surface electronic states in metal-porous silicon-silicon structures

The character of electronic states in porous silicon (PS)-Si, Pd-PS interfaces, and/or PS bulk at the formation of the metal-PS-silicon heterostructure was studied. The energy parameters were estimated using the deep-level transient spectroscopy and capacitance-voltage characteristics at the accounting of the voltage drop distribution along the structure. The analytical expression for voltage drop distribution along dielectric layer, porous layer and space charge region in silicon was obtained by solving the equation for continuity of the electrostatic induction vector. The electronic states studied were shown to manifest the quasi-continuous sub-band in the energy gap if the porous layer was 30-nm thick. Their density increased, as the energy position was being transformed to a deeper energy level of E_v+0.81 eV at the PS layer growing to 90 nm wide.     

Linked influence of pH and cations on fatty-acid monolayer integrity related to high-quality Langmuir-Blodgett films

This study shows the connection between the morphological structure of transferred films and the chemical composition of the monolayer before transfer. The stability of a behenic acid monolayer depends on the linked influence of the type of cation and of the pH value in the aqueous subphase. The stability of the monolayer is assessed by the expansion of the solid-packed state and by the relaxation time. Its integrity is characterized by the number of crystal defects which appear in transferred Langmuir-Blodgett (LB) films as seen through Nomarski microscope observations. Both stability and integrity are greatly improved when Cd²⁺ or Mn²⁺are added to the subphase at pH 5.75 and 6 respectively. In these conditions, the transfer is very efficient and the LB films thus obtained are of very high quality. The pH values of the subphase at which the molecules of behenic acid are transformed into bivalent salts differ significantly according to the nature of the cation involved. Comparing infrared spectra of the LB films, it appeared that the relative amount of acid/salt found in the monolayer was practically the same with a subphase containing either Cd²⁺ at pH 5.75 or Mn²⁺ at pH 6. This suggests that the ratio of acidic and salt forms would be a key parameter for obtaining high-quality LB films.     

传统机械加工表面形貌评定的缺陷及发展方向

本文通过对传统机械加工表面形貌评定体系的分析，指出其不能完整地、从本质上反映表面的特征。并提出轮廓长度率、表面真面积率、表面分形维数D、比例系数K四个评定参数，通过分析可以看出这组参数比传统方法所具有的优越性和代替传统方法的可能性。     

Kevlar－49芳纶纤维表面接枝改性

采用空气等离子体处理Ｋｅｖｌａｒ－４９并在活化处理后的纤维表面接枝聚丙烯酸（ＰＡＡ）、聚丙烯酸乙酯（ＰＥＡ）及丙烯酸和丙烯酸乙酯的共聚物（ＰＡＡ／ＥＡ）。单丝拔出实验研究表明，空气等离子体改性的Ｋｅｖｌａｒ－４９／环氧树脂体系的界面结合强度和界面破坏能均有明显提高，其中接枝了Ｐ（ＡＡ／ＥＡ）的Ｋｅｖｌａｒ－４９／环氧树脂体系的界面破坏能（５５Ｊ／ｍ２）比未改性体系的界面破坏能（２７．８Ｊ／ｍ２）提高了一倍。     

国际微电子专用关键设备的现状和发展趋势（考察报告）

讲述了参观Ｓｅｍｉｃｏｎ／ｗｅｓｔ９４′展览会及考察美国和西德的５个公司、１所大学所了解到的投影光刻技术、电子束曝光技术、透镜面形测试技术的发展。     

Surface Chemistry and Catalysis of Rare Earth Oxides I．A Study of the Reactivity of Surface Hydroxyls on CeO_2 and Pr_6O_（11） by FT－IR Spectroscopy

ＳｕｒｆａｃｅＣｈｅｍｉｓｔｒｙａｎｄＣａｔａｌｙｓｉｓｏｆＲａｒｅＥａｒｔｈＯｘｉｄｅｓＩ．Ａ　ＳｔｕｄｙｏｆｔｈｅＲｅａｃｔｉｖｉｔｙｏｆＳｕｒｆａｃｅＨｙｄｒｏｘｙｌｓｏｎＣｅＯ_２ａｎｄＰｒ_６Ｏ_（１１）ｂｙＦＴ－ＩＲＳｐｅｃｔｒｏｓｃｏｐｙ...     

A dynamic integration algorithm to model surfaces from multiple range views

This paper presents a dynamic integration algorithm to triangulate a surface from multiple range views. This integration technique is based on the reparameterization of the canonic subsets of the Venn diagram of the set of range views. We compute a model based onN views from a model based onN–1 views by processing only the surface segments visible in theN ^th view. An experimental result shows that the proposed integration algorithm can process complex multipart objects containing holes.     

Application of Rachinger''s method to separate overlapped doublets in the X-ray photoelectron spectrum

Rachinger's method of separating ₁ and ₂ doublets in X-ray emission spectra is applied for the first time to separate the superimposed doublets due to spin-orbit coupling. This method has been applied to separate closely lying doublets such as (Ag 4p_3/2and Ag 4p_1/2, (Ni 3p_3/2and Ni 3p_1/2) and (Cu 3p_3/2and Cu 3p_1/2). The intensities ratios of the separated peaks are measured and compared with the ratios obtained from a first-order calculation. An excellent agreement between the measured and calculated ratios are obtained. Residual background intensities compared with the estimated values are found to agree within certain uncertainties.     

SURFACE TENSION AND BUOYANCY DRIVEN INSTABILITIES IN A LAYER OF LIQUID TIN HEATED FROM BELOW

The linear theory of Pearson (1958) and Nield (1964) is modified here to study liquid tin and include the finite thermal resistances of the bounding layers of boron nitride, copper and air (∼10^-2 torr) in the experiments of Ginde et al. (1989). The magnitude of the ΔT_c across the layer of liquid tin required for the onset of convection depends on the ratios of the thermal conductivities and thicknesses of the supporting layers of boron nitride and copper to those of the tin.

According to our theory surface tension contributes more than buoyancy to the instability observed experimentally. The critical ΔT_c observed required for the onset of convection in the layer of tin, is up to 25% lower than that predicted, which shows the layer is less stable than the theory indicates. Thus the surface of the tin was uncontaminated, or a significantly larger observed critical ΔT_c would be expected.

The boundary condition on the thermal fluctuations at the base of the supporting layer of copper does not appear to be important in these experiments. However, the thermal resistance of the boron nitride would have to be assumed to be unrealistically large to obtain agreement within experimental error with the theory.