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81.
A study of the pyrolysis of an aqueous solution of manganese nitrate in the presence of silver compounds has been carried out. Thermal analysis showed that the MnO2 formation temperature and the transformation temperature from MnO2 to Mn2O3 shifted towards a lower temperature in the presence of silver acetate. A large particle-size and high crystallinity MnO2 was formed; this may be a useful method of making an excellent tantalum capacitor with high capacitance.  相似文献   
82.
用光致荧光谱、傅里叶变换红外光谱(FTIR)和扫描电子显微镜(SEM)对用阳极氧化法制成的多孔硅层在1%NH3/H2O2溶液中的腐蚀现象进行了研究。红外分析表明,Si-O键和H-O键的强度随NH3/H2O2溶液的腐蚀时间的增加而增加,Si-H键强主匠随腐蚀时间增加而减少。光致荧光谱的峰值在腐蚀开始时先下降后上升,半高宽变窄,谱峰的以边明显蓝移。分析研究表明,1%NH3/H2O2溶液对多孔硅层有腐蚀  相似文献   
83.
We investigated the effect of Fe contamination on the electronic properties of dislocation clusters in relation to oxygen precipitation in multicrystalline silicon (mc-Si). Photoluminescence (PL) spectroscopy and mapping were performed at room and liquid-He temperatures on mc-Si wafers before and after Fe contamination. PL spectra consisted of the band-edge emission, the 0.78-eV emission associated with oxygen precipitates, and the dislocation-related D-lines. The Fe contamination increased the electrically active dislocation clusters. Part of these clusters acted as preferential oxygen precipitation sites, and their electronic properties were not further influenced by the Fe contamination.  相似文献   
84.
Using our designed robot, previous work has confirmed that bimanual training induced greater oxygenated-hemoglobin concentration than unilateral-limb training. However, the inter-hemispheric asymmetry of oxygenated-hemoglobin concentration was not compared between the bimanual and unilateral-limb patterns. To confirm the merits of our designed robot based on cerebral hemoglobin activation, 18 healthy subjects performed bimanual and unilateral-limb tasks in active-resisted mode and active-assisted mode for the right and left control sides (determines from that which limb provides a larger force). Analyses of variance were performed to compare the laterality index (LI) of two hemispheres between the two control sides, and to compare oxygenated-hemoglobin concentration between the different training patterns. The difference of LI between the two control sides was distinct in unilateral-limb patterns (p?=?0.029) but not obvious in bimanual patterns. As for the oxygenated-hemoglobin, active-resisted tasks induced a higher concentration than active-assisted tasks in the left control side (p?=?0.048). Results demonstrated that the proposed bimanual training induced the functional integrity of two hemispheres, and the robot is favorable for improving bimanual movement-coordination function. Additionally, active-resisted tasks had a higher difficulty level than active-assisted task. Therefore, the robot has a potential for delivering strength enhancement training in bimanual patterns.  相似文献   
85.
86.
The specific interactions between several low‐molecular‐weight diamino compounds and poly(ε‐caprolactone) (PCL) have been investigated by FT‐IR. It was found that PCL and 3,3′‐diaminodiphenylmethane (3,3′‐DADPM) interact through strong intermolecular hydrogen bonds in the blend. Thermal and mechanical properties of PCL/3,3′‐DADPM blends were investigated by DSC and tensile measurements, respectively. The glass transition temperature of the blend increases while both the melting point and the elongation‐at‐break of the blend decrease with the increase of 3,3′‐DADPM content. Besides 3,3′‐DADPM, several other low‐molecular‐weight compounds containing two amino groups, such as o‐phenylenediamine or 1,6‐diaminohexane, were also added into PCL and the corresponding blend systems were investigated by FT‐IR and DSC. The effect of the chemical structure of the additives on the properties of PCL is discussed. © 2001 Society of Chemical Industry  相似文献   
87.
To obtain dense, fine-grained ceramics, fine particles and advanced powder processing, such as colloidal processing, are needed. Al2O3 and ZrO2 particles are dispersed in colloidal suspensions by electrosteric repulsion because of polyelectrolyte absorbed on their surfaces. However, additional redispersion treatment such as ultrasonication is required to obtain dispersed suspensions because fine particles tend to agglomerate. The results demonstrate that ultrasonication is effective in improving particle dispersion in suspensions and producing a homogeneous fine microstructure of sintered materials. Superplastic tensile ductility is improved by ultrasonication in preparing suspensions because of the dense and homogeneous fine microstructure.  相似文献   
88.
The preparation of oriented AlN bulk ceramics with and without additives was achieved by slip casting in a high magnetic field. The a and b axes of the AlN were aligned parallel to the direction of the magnetic field. The degree of crystallographic orientation was controlled by the viscosity of the slurry and the grain growth during sintering attributed to the sintering additives. The mechanical properties of the textured AlN depended on the direction of the crystallographic orientation.  相似文献   
89.
An experiment was carried out to examine heat and mass transfer between constant-temperature water and dry air through a porous plate having extremely small pores. The effects of the thermal conductivity in the porous plate on moisture transport were investigated. The controlling factor for moisture transport was found to be the thermal resistance inside the porous plate having a low-thermal-conductivity and the heat transfer at the surface of the porous plate having a high-thermal-conductivity.  相似文献   
90.
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