查询词典 Fermi

Crystal Structure; Reciprocal Lattice; Crystal Binding; Phonon; Free Elecron Fermi Gas; Energy Bands; Semiconductor Crystals; Superconductivity; Dielectrics and Ferroelectrics; Diamagnetism and Paramagnetism; Ferromagnetism and Antifierromagnetism; Magnetic Resonance.

晶体结构、反商晶格、晶体链结、声子、自由电子费密气、能带、半导体晶体、超导体、介电材料与铁电材料、抗磁与顺磁、铁磁与反铁磁、磁与共振。

Especially, we obtain simplified expressions of the energy dispersion relations and wave functions near the Fermi level of metallic nanotubes.

尤其是，在金属管费米面附近，得到了简化的能量色散关系及波函数表达式。

Compared with the density of states of the alloying system, the increase of the structural stability of Mg-Al alloy with Sb or Bi additions attributes to an increase in the bonding electron numbers at lower energy level below Fermi level, which mainly originates from the contribution of the valence electron numbers of Mg, Mg, Al, Bi and Sb orbits.

电子态密度的分析结果进一步表明，Mg-Al系合金中相结构稳定性提高的主要原因在于：Sb、Bi合金化后，体系费米能级以下低能级区成键电子数的增多，其来源主要是Mg、Mg、Al、Bi和Sb的价电子。

The results show that there are some function relationships between the dielectric constant of solvent and the intensity ratio of Fermi resonance.And the empirical formula was obtained by curve fitting.

研究发现溶剂的介电常数与费米共振的强度比之间存在一定的函数关系，通过曲线拟合得到费米共振的强度比与溶剂介电常数之间关系的经验公式。

The influences of the shock thickness and Alfven waves on the particle acceleration by diffusive shock waves are numerically studied through solving one-dimensional diffusive equation including the second-order Fermi effect. It is shown that the spectral index of the energetic particles strongly depends on the shock thickness. For example, the spectral index increases from 2.1 to 3.7 in the low energy range of 3-10 MeV and from 2.5 to 5.0 in the high energy range of 20-60 MeV as the thickness increases. The spectral index decreases from 4.3 to 3.1 as the particle injection energy increases. The spectral index decreases from 4.0 to 1.8 at the quasi-steady stage with the enhancement of the compression ratio from 2 to 4. The results indicate that under the influence of Alfven waves, the energetic particle spectrum at lower energy becomes flat and the spectral index decreases from 2.5 to 0.6 in the low energy range of 3-10 MeV and from 11.6 to 5.0 in the high energy range of 20-60 MeV. At the same time, the rollover energy reaches 19.6 MeV. The spectral index decreases from 5.8 to 2.9 as the energy density of Alfven waves increase. All these results are basically consistent with the theoretical models, as well as the observations of typical energetic particle events.

通过数值求解包含二阶费米加速的一维扩散方程，探讨在准平行激波条件下激波厚度和级联阿尔芬波对粒子加速的影响，研究粒子分布函数的演化与激波厚度和阿尔芬波强度的内禀关系，计算结果表明：(1)考虑激波厚度时，谱指数明显依赖于激波厚度，随着厚度从0.32增大到2.56，低能端(3-10MeV)谱指数逐渐从2.1增加到3.7，高能端(20-60MeV)谱指数从2.4增大到5.0，能谱逐渐变软；当初始注入粒子动量增大1.3倍，质子能谱指数从4.3减小到3.1，且与零厚度激波加速的谱指数差值缩小；厚度不变时，随着压缩比从2增加到4，准稳态分布时低能端(3-10MeV)粒子能谱指数逐渐从4.0减小到1.8谱变硬；(2)在级联阿尔芬波的影响下，随着时间的增大，粒子在低能处(3-10MeV)的谱指数从2.5减小到0.6高能端(20-60MeV)谱指数从11.6减小到5.0，能谱变硬，拐点能量值从7.5MeV增大到为19.6MeV；随着波的能量密度增大，谱指数从5.8减小到2.9，这表明阿尔芬波强度越大，加速效率越高，通过与激波厚度解析结果和高能粒子事件的观测能谱比较发现两者是一致的，说明数值模拟结果是可靠的。

Some important parameters are estimated according to experimental results,such as Fermi energy E-F and energy band width.

估算了一些重要的参数，如带米能EF、能带宽度等。

The main work can be summed up as follows: Firstly, we studied the thermal-field properties of VCSELs, and analyzed the influences of current spreading, material parameters and operating conditions on the temperature distributions. Secondly, we began with the electrode voltage and calculated the equipotential s distributions, compared the distributions of voltages and current densities in different depths of VCSELs, and then studied the influences of the oxide-confining region with different position or thickness, and the different sizes of the gain-guided aperture and emitting window on the distributions of the injected current density, carrier concentration and temperature in the active region. Thirdly, we realized the coupling of electricity, optical and thermal-fields, worked out the threshold voltage, calculated the distributions of the injected current density, carrier concentration and temperature under different offset voltages, and analyzed the impacts of temperature profile and carrier density on the refractive index, Fermi levels and optical-field. Finally, we gave the equipotential line distributions with considering N-DBR and double oxidized-confining regions, and analyzed theinfluences of N-DBR and double oxide-confining regions on the distributions of the current density, carrier concentration, temperature and optical-field.

具体工作可以概括如下：首先，研究了VCSEL的热场特性，分析了电流扩展，材料参数和工作条件对于温度分布的影响；其次，从电极电压入手，计算出激光器中的等势线分布，并对不同深度处的电压和电流分布进行比较，研究了高阻区的不同位置和不同厚度、限制层和出射窗口半径的大小对电流密度、载流子浓度和温度分布的影响；再次，实现了电、光、热耦合，求出了阈值电压，计算了不同偏置电压下的电流密度分布、载流子浓度分布和热场分布，分析了温度和载流子浓度变化对折射率、费米能级和光场的影响；最后，给出了考虑N-DBR和双氧化限制层时激光器中的等势线分布，分析了N-DBR和双氧化限制层对VCSEL电流密度、载流子浓度、温度和光场分布的影响。

Since Fermi's death in 1954, no physicist has been at once a master experimentalist and a leading theoretician.

自1954年费米去世后，还没有哪一位物理学家同时是一名精通的实验主义者和一名最主要的理论家。

Based on the free electronic band model, we study the relationship between average bond energy E m and Fermi level E F in face centered cubic crystal, body centered cubic crystal and hexagonal closed packed structure crystal.

根据半导体自由电子能带模型，文中在面心立方晶体、体心立方晶体和 6角密堆积晶体中研究自由电子能带的平均键能 Em 和费米能级 EF 的关系，并得出自由电子能带的平均键能 Em 相当于费米能级 EF 的研究结果。

This is the prospect of the universe; this is the explanation to Fermi Paradox.

这就是宇宙文明的图景，这就是对费米悖论的解释。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。