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311.
设BδA,*是由Bochner-Riesz算子生成的极大多线性Bochner-Riesz算子,其中DγA∈Λ.β(|γ|=m).获得这个算子及其变形在中心Campanato空间的连续性. 相似文献
312.
Oxygen nonstoichiometry (δ) of “undoped” polycrystalline TiO2−δ has been measured as a function of oxygen partial pressure in the widest ever examined range of 10-18?PO2/atm?10-1 at elevated temperatures (1073?T/K?1473) by thermogravimetry and coulometric titrometry combined and compared with all the reported values. Isothermal variation of nonstoichiometry against PO2 is explained with a defect model involving quadruply ionized titanium interstitials, electrons, holes, and unidentified acceptors which may be background impurity acceptors or cation vacancies. The equilibrium constants for intrinsic electronic excitation reaction and redox reaction are determined from the nonstoichiometry measured and compared exhaustively with all the reported values. The relative partial molar enthalpy and entropy of oxygen are evaluated as functions of nonstoichiometry and the inner workings of their variations discussed. 相似文献
313.
利用溶胶-凝胶方法在800 ℃焙烧10 h后, 合成了固溶体Ce1-xNdxO2-δ (x=0.05~0.55), X射线衍射(XRD)测试表明固溶体已经形成立方萤石结构; 电子顺磁共振谱(EPR)研究表明在固溶体Ce1-xNdxO2-δ中随着掺杂量x的增大, Ce3+离子含量减少, 说明掺杂Nd3+离子可以抑制Ce4+的还原; 交流阻抗谱的测量表明固溶体Ce0.9Nd0.1O2-d 具有离子导电特性, 600和700 ℃时的电导率分别为4.25×10-3和1.12×10-2 S•cm-1, 活化能为0.68 eV. 相似文献
314.
The phases LaxSr2−xFeyRu1−yO4±δ (x=0.2-0.8; y=0.6-0.9) have been synthesized by solid-state techniques and yield tetragonal structures with I4/mmm symmetry. The oxygen stoichiometry and high-temperature structures have been examined using diffraction techniques and in situ Mössbauer spectroscopy at temperatures up to ∼600°C. Furthermore, new reduced phases that adopt structures with Immm symmetry have been discovered. Unusual coordination numbers have been determined for the most highly reduced samples with square planar coordination evident for the B site cations. The reduced orthorhombic Immm phases were found to readily reoxidize in air to the tetragonal I4/mmm structure at relatively low temperatures of only ∼500°C. 相似文献
315.
《电子科技学刊:英文版》2023,21(2):100203
The viability of the indium phosphide (InP) Gunn diode as a source for low-THz band applications is analyzed based on a notch-δ-doped structure using the Monte Carlo modeling. The presence of the δ-doped layer could enhance the current harmonic amplitude (A0) and the fundamental operating frequency (f0) of the InP Gunn diode beyond 300 GHz as compared with the conventional notch-doped structure for a 600-nm length device. With its superior electron transport properties, the notch-δ-doped InP Gunn diodes outperform the corresponding gallium arsenide (GaAs) diodes with up to 1.35 times higher in f0 and 2.4 times larger in A0 under DC biases. An optimized InP notch-δ-doped structure is estimated to be capable of generating 0.32-W radio-frequency (RF) power at 361 GHz. The Monte Carlo simulations predict a reduction of 44% in RF power, when the device temperature is increased from 300 K to 500 K; however, its operating frequency lies at 280 GHz which is within the low-THz band. This shows that the notch-δ-doped InP Gunn diode is a highly promising signal source for low-THz sensors, which are in a high demand in the autonomous vehicle industry. 相似文献
316.
利用数学模型δ(n,d,k),按照组合群验的理论和算法,根据选拔运动员的评价指标类和指标权重,给出了从大量选手中筛选优秀运动员的一种新方法. 相似文献
317.
李娟 《数学物理学报(A辑)》2007,27(3):515-523
该文证明了满足A -调和方程的微分形式的局部双权积分不等式. 作为局部结果的应用,还证明了满足A -调和方程的微分形式的整体双权积分不等式. 相似文献
318.
对c轴择优取向的熔融织构样品(Nd0.33Eu0.33Gd0.33) Ba2Cu3O7-δ(含Gd(211)相)的磁通跳跃现象进行 了系统研究.结果表明,在外加磁 场平行于样品c轴条件下,在2到3K的温度范围内明显观测到了部分磁通跳跃现象,而 在5K及以上温区并未出现.在磁场垂直于样品的c轴情况,在2K到Tc的整个温 区都没有观察到磁通跳跃现象.这种各向异性磁通跳跃现象可归因于各向异性钉扎力和几何 退磁因子的结果.随着温度的增加,磁通跳跃数目减少,且M(H)曲线的第三象限是磁通 跳跃的最不稳定过程.最后,研究了磁通跳跃对磁场扫描速率的依赖关系,并讨论了磁通蠕 动对磁通跳跃的影响.
关键词:
0.33Eu0.33Gd0.33)Ba2Cu3O7-δ超导体')" href="#">(Nd0.33Eu0.33Gd0.33)Ba2Cu3O7-δ超导体
OCMG方法
磁通跳跃 相似文献
319.
320.
This paper propose to analyse the effect of the shape factor that is used in plasma PIC δf codes to make interpolations between the grid and the particles positions. In δf codes, the total density fluctuates, even when it should be conserved. We show that, in some cases, the computed non-physical part of the particle kinetic energy fluctuations is dependent on those of the total density. We deduce a method that can reduce drastically the statistical fluctuations in the diagnostics of the kinetic energy. 相似文献