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1.
Recrystallization and Phase Transformation in Reaction-Sintered Sic   总被引:1,自引:0,他引:1  
Reaction-sintered Sic specimens prepared at ∼1500°C and heat-treated at ∼1850°C in the presence of molten silicon were examined by transmission electron microscopy. The β-Sic grains in as-prepared specimens grew to a large size when heat-treated in the presence of molten Si; the number of growth twins in such °-Sic crystals was very small. The boundary areas of α- and β-Sic crystals were microsyntactic, consisting of thin strips of α- and β-Sic after heat-treating. These changes were due mostly to thin lamellar growth of α-Sic into β-Sic grains along the basal plane. There is also a high density of similar growth of transformation twins in β-Sic crystals. The results provide clear evidence of in situ solid-state transformations in sic.  相似文献   
2.
殷澍  王金淑  佐藤次雄 《功能材料》2004,35(Z1):2503-2506
介绍一种低温合成二氧化钛纳米粒子的新方法.将非晶型二氧化钛加入强酸性溶液中室温搅拌数小时后得到无色透明的溶液.继续在室温搅拌数48h后,可以得到高比表面的金红石相二氧化钛纳米粒子.改变处理过程温度及酸的种类,可以得到不同组成的纤维状二氧化钛纳米粒子.对盐酸体系进行详细讨论结果表明,在低于60℃时得到的是热力学稳定的金红石单一相,而在高于120℃时得到的是热力学亚稳态的锐钛矿单一相,高于170℃时得到的是锐钛矿及金红石的混合相,显示出与众不同的结晶行为.通过此低温法制备的金红石相二氧化钛在具有较小的吸收禁带的同时,还拥有100n2·g-1以上的比表面积.与锐钛矿相相比,显示了良好的可见光催化活性.  相似文献   
3.
The spin‐dependent scattering of conduction electron in metallic magnetic multilayers was investigated to reveal the optical properties which corresponded to the magnetization state. From the measurement of magnetorefractive effect in antiferro‐magnetically exchange coupled Co/Ru multilayers, it was found that (1) the transmittance varied around 1% at wavelength of 1550 nm during the parallel/antiparallel spin alignment changes, (2) as a result of number of repetition and Co thickness for the multilayers, transmittance difference between the parallel and antiparallel spin alignment states had trade‐off relationship with the magnitude of transmittance, and (3) asymmetric Co/Ru/Co stacking structure brought different interlayer exchange coupling fields in each layer, which resulted in magnetic field sensitive transmittance.  相似文献   
4.
One way of reducing the energy consumption of trains is to drive them in an energy‐efficient manner. There can be various driving patterns between two adjacent stops, or various speed profiles, because there is a gap called the running time supplement between the planned running time set in a timetable and the shortest possible running time of the train. Previous studies have proposed using up the supplement by changing the driving operation from powering to coasting at optimal points in terms of energy consumption. Others have shown that full use of regenerative braking helps save energy. In this study, we developed an energy‐efficient speed profile generator by combining these partial energy‐oriented driving approaches when the planned running time is given. We added this generator to existing shortest running time calculation software, so that it works for various vehicle and train route data. Numerical experiments showed that our profile provided superior performance compared to manually created ones for artificial and real data.  相似文献   
5.
We developed the 550‐kV disconnectors that strengthened earthquake proofing by the addition of the damper unit and weight reduction of conductive part based on the damage of the 550‐kV disconnectors by the Great East Japan earthquake (March 11, 2011) and inspected the earthquake proofing performance by shake table test. In shake table test, we performed the test by the artificial seismic wave that varied in phase characteristic in addition to the test by resonance method. And, in a high‐level earthquake area, we analyzed it about the influence that a phase characteristic of the artificial seismic wave gave to stress to occur in disconnectors. As a result, it is thought that the stress to occur in disconnectors is decided by a primary natural frequency basically because a bending strain to occur to the disconnectors in the time when the resonance frequency ingredient becomes the big acceleration response value grows big. But, on a particular phase condition, it was confirmed that the bending strain to occur in disconnectors might grow big conspicuously. As for this, the possibility is thought about by influence of higher natural frequency doing superposition.  相似文献   
6.
如何受益硅烷偶联剂的奇妙功效   总被引:1,自引:0,他引:1  
介绍了硅烷偶联剂的常规品种和新型产品:简述了硅烷偶联剂的作用机理和性能改进;总结了硅烷偶联剂的使用方法和注意要点:提出了只有正确使用才能奇效凸显,获益匪浅。  相似文献   
7.
制备了陈皮挥发油提取物并建立其气相色谱-质谱(GC-MS)指纹图谱,对不同批次的陈皮指纹图谱进行相似度评价;对其共有成分峰面积数据进行主成分分析(PCA)和层次聚类分析(HCA)。建立了具有16个共有峰的新会陈皮挥发油指纹图谱,通过化学计量学分析方法能将新会陈皮和其他陈皮样品准确区分开来;不同采摘期及贮存时间陈皮的成分呈现规律性特征。方法可用于不同产地、采摘期及贮存时间陈皮的鉴别,并为陈皮的质量控制提供依据。  相似文献   
8.
Changes in the phase composition and microstructure of yttria-partially-stabilized zirconia by low-temperature annealing were investigated at 100° to 500°C using bodies sintered from coprecipitated fine ZrO2-Y2O3 powders at varied temperatures. Tetragonal zirconia on the surfaces of bodies sintered at <1500°C transformed to the monoclinic phase at 100° to 400°C. Transformation behavior was strongly affected by grain size.  相似文献   
9.
10.
Dry electrodes of a smart shirt for measuring biological signals were prepared by the additive printing method using a stretchable conductive paste with Ag fillers loading. Interfacial impedance between the electrode and skin depended on the contact pressure of electrode and the moisture of stratum corneum. When moisture of stratum corneum was more than 30%, ECG could be measured using the stretchable electrodes printed on a compression shirt. However, noise signal in the ECG signal increased when the moisture of stratum corneum was less than 30%. To solve this problem, we propose to use additional electrodes made of an electrically conductive kneaded rubber.  相似文献   
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