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141.
Imran M. Zainuddin Masatoshi Yasuda Takehiko Horio Shuji Matsusaka 《Particle & Particle Systems Characterization》2012,29(1):8-15
The flowability of powders with different mass median diameters ranging from micrometers to nanometers was measured using the vibration shear tube method. In the measurement system used in this study, the powder was discharged through a narrow gap between a vibrating tube edge and a flat bottom surface, where each particle could experience high shear forces to overcome the adhesion and friction forces. The vibration amplitude was increased during the measurement, and the mass of particles discharged was measured at constant time intervals. From the relationship between the mass flow rate and the vibration acceleration, static and dynamic properties of the powders were evaluated using the critical vibration acceleration, characteristic mass flow rate, and gradient of mass flow rate. The correlation between the static and dynamic properties was studied in detail. 相似文献
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143.
P. Morgan Pattison Rajat Sharma Aurelian David Ichitaro Waki Claude Weisbuch Shuji Nakamura 《physica status solidi (a)》2006,203(7):1783-1786
A gallium nitride based micro‐cavity light emitting diode emitting at a peak wavelength of 498 nm has been fabricated. The epitaxial structure was grown by metalorganic chemical vapor deposition, and the device was fabricated using a laser lift‐off process. Cavity thinning was carried out using reactive ion etching until a cavity length of roughly 830 nm (corresponding to a cavity order of ∼8 for λ = 498 nm in GaN) was achieved. Electroluminescence measurements of the micro‐cavity device show a narrowed spectral width compared to the un‐thinned device, and angularly resolved spectral measurements yielded a spectral shift, evincive of micro‐cavity effects. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
144.
Bilge Imer Matt Schmidt Ben Haskell Siddharth Rajan Barry Zhong Kwangchoong Kim Feng Wu Tom Mates Stacia Keller Umesh K. Mishra Shuji Nakamura James S. Speck Steven P. DenBaars 《physica status solidi (a)》2008,205(7):1705-1712
High quality nonpolar a ‐plane GaN templates were grown by utilizing sidewall lateral epitaxial overgrowth (SLEO) technique with threading dislocation density of ∼106–107 cm–2. 360 nm GaN/AlGaN multiple quantum well ultraviolet light emitting diodes were grown with metalorganic chemical vapor deposition. Reduced defect density SLEO a‐ plane, planar a ‐plane, and planar c ‐plane templates were co‐loaded for device growth and processed together in order to make relative device performance comparison. For SLEO a ‐plane LEDs E EL peak position was measured at 360 nm and it was independent of drive current. The linewidth of the emission was 7 nm. The series resistance of these diodes was as low as 16.5 Ω and the forward voltage was measured as 4.08 V at 20 mA. The external quantum efficiency of the high quality SLEO a ‐plane devices was ∼275× higher than planar a ‐plane devices. The highest output power was realized at 200 mA as 65 μW. The effect of contact geometry on electrical and optical characteristics of the devices was also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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147.
Shuji Watanabe 《Proceedings of the American Mathematical Society》1997,125(1):129-136
Spaces of Sobolev type are discussed, which are defined by the operator with singularity: , where and . This operator appears in a one-dimensional harmonic oscillator governed by Wigner's commutation relations. Smoothness of and continuity of () are studied where is in each space of Sobolev type, and results similar to Sobolev's lemma are obtained. The proofs are carried out based on a generalization of the Fourier transform. The results are applied to the Schrödinger equation.
148.
在阴离子交换树脂催化剂上合成二丙酮醇的动力学研究 总被引：1，自引：0，他引：1
动力学研究表明,在碱性树脂催化剂上丙酮缩合制二丙酮醇是一个1-1级可逆反应,本文对此多相催化的反应机理进行了探讨。 相似文献
149.
平面调制靶的表面起伏图形研制 总被引：5，自引：2，他引：3
表面起伏靶是惯性约束聚变（ＩＣＦ）分解实验中的重要实验用靶。本文报导了采用离子束刻蚀和激光干涉两种方法制备初始微扰振幅和波长分别在几微米和几十微米范围的正弦调制形状;摸索了相应的工艺条件和工艺过程;用台阶仪及光学显微轮廓仪测微加工后的形貌;探讨了调制波长的精确控制与干涉工艺之间的关系。 相似文献
150.
镍 钴 钯 铁2—（二苯基膦基）吡啶配合物的合成及其催化羰基化反应 总被引：1，自引：1，他引：0
众所周知,铑催化剂是醇类羰基化的有效催化剂,但是铑价格昂贵且对设备有腐蚀性,因此,寻找出对醇类羰基化催化活性好的非贵金属催化剂,对醇类羰化的工业化有十分重要的意义。 本文在温和条件下,合成了四种含有相同配体(Ph_2PPy)不同金属的有机配合物(金属基分别为Ni、Co、Pd、Fe),并探索了它们对乙醇羰基化反应的催化活性。 相似文献