损耗

PIC results show that the occurrence of absolute instability is determined by the operating current.

通过PIC模拟，给出了采用无损耗波导结构，且工作电流为25A和10A条件下的放大器频谱图和功率图，结果表明绝对不稳定性的出现与否主要由工作电流是否超过起振的阈值电流决定，损耗波导是抑制绝对不稳定性的有效手段。

The numerical results show that lossy dielectric-load can heighten the start oscillation current of absolute instability, and increase depends on the magnetic field strength and the perpendicular-to-parallel velocity ratio of the electrons; The thickness of the lossy waveguide increases the start oscillation length of backward wave oscillation.

结果表明：损耗介质的加载，可以提高绝对不稳定性起振电流，提高的幅度依赖于工作磁场偏离饱和磁场的程度、电子束横纵速度比等；增加波导损耗介质加载的厚度，可以提高竞争模式的回旋返波起振长度。

Therefore, the interaction structures with distributed wall losses and attenuating severs were more stability for absolute instability and gyrotron backward oscillations.

藉由引用非线性程式进行磁旋行波放大器稳定分析，结果显示散布式损耗(distributed-losses)的设计对绝对不稳定有明显的抑制作用，而隔离管结构亦具有减短磁旋返波振荡作用长度的效用，因此我们采用兼具隔离管及散布式损耗结构的磁旋行波放大器，同时提升绝对不稳定和磁旋返波振荡的稳定性。

This paper, with the analysis of the propagation characteristics in a lossy cylindrical waveguide and using small-signal theoretical dispersion relation, presents study on the device stability with influence of the absolute instability and the backward wave oscillation in TE01-mode lossy dielectric-load gyrotron traveling wave amplifier.

摘要该文从分析损耗介质加载金属圆波导中电磁波传输特性出发，应用回旋行波管放大器小信号色散方程，研究损耗介质加载结构TE01模回旋行波管放大器绝对不稳定性振荡和回旋返波振荡对器件稳定性的影响。

Return loss is one of the important indices, which is used to evaluate the absorbing characteristic of the microwave anechoic chamber, so the test of it comes into one of the important aspects of examining the characteristic of th e microwave anechoic chamber.

微波暗室的回波损耗是衡量微波暗室吸收特性的一个重要指标，因此对微波暗室的回波损耗的检测是检验微波暗室性能优劣的一个重要方面。

Effects of angular frequency on storage modulus, loss modulus, loss factor and dynamic viscosity! were investigated.

用扩展流变仪测定了PET，PET-GF，PET-GF-EGMA熔体的储能模量、损耗模量、损耗因子和动态黏度等随角频率的变化规律。

In the paper, the principle and matrix description of the switch is expounded, and the aplanatism of signal lights is also testified, and the insert loss and polarization dependent loss is analysed.

本文将阐述光开关的原理与矩阵分析，论证这种自由空间光开关的等程性，讨论新型光开关结构与性能(插入损耗与偏振相关损耗)。

"The reason we're losing natural capital is because it's free," says Ed Barbier, noting that we often think of conservation in terms of its costs rather than its value, and regard manufactured goods in terms of value rather than their environmental costs.

Ed Barbier认为我们经常从自然的损耗而不是它的价值来考虑保护环境，而对于制成品，我们考虑的是它的价值而非它对大自然的损耗。

The result indicates that the poach dissipation of ceramics can be reduced when low impurity constant barium carbonate raw material with spheroidal particles is used;and the relationship of dielectric constant to temperature is more stabilized.

结果表明，杂质含量低、球形颗粒的碳酸钡原料能显著降低陶瓷的水煮损耗，但陶瓷水煮损耗异常和其致密性不存在对应关系。

Microscopic characteristics of cladded crystal fiber are analyzed by X-ray diffraction, Laue X-ray diffraction and scanning electron microscopy, it is found that magnesium-ion indiffusion does not affect the single crystal structure and the domain structure of the magnesium diffused crystal fiber. It is found for the first time that MgO-rich layer in the magnesium diffused LiNbO〓 surface layer exhibits the crystal structure of an unknown compound from the Li-Mg-Nb-O ternary system and MgNb〓O〓. It is proposed for the first time that this unknown compound and MgNb〓O〓 in MgO-rich layer are the real sources of magnesium-ion indiffusion LiNbO〓. Their appearance indicate that MgNb〓O〓 is in the surface layer of MgO-rich layer, the unknown compound is in the subsurface layer and beneath where the MgNb〓O〓 is located, and these compounds have obviously preferred orientation.

通过镁离子内扩散法，首次在国内实现了具有阶跃和抛物折射率分布的c轴LiNbO〓单晶光纤和a轴Nd：MgO：LiNbO〓单晶光纤的芯—包层波导结构，为我国在该项目的研究填补了空白；建立了晶纤损耗的测量系统，提出了利用单模石英光纤作为晶纤入射光耦合器的思想；通过对晶纤损耗的测量，得到了包层晶纤比未包层晶纤损耗降低约14倍的好结果，并实现了低次模传输：对经镁离子内扩散实现包层后的晶纤的微观特性，利用X射线衍射，劳厄照相和扫描电镜表征发现，晶纤并不因镁离子的内扩散而影响其单晶结构和镁的扩散层畴的变化。

Objective: To study the effect of polycythemia on blood oxygen saturation.

裴蕾目的：观察RBC剧增而引起的高粘血症对血氧饱和度的影响。

Based on SIMPLER algorithm in the curvilinear body-fitted coordinates, the calculations were performed for Pr=0.7, Re=10~1000 on non-orthogonal non-staggered grids which are generated by elliptic equation systems.

采用曲线坐标系下压力与速度耦合的SIMPLER算法，数值研究了周期性渐扩渐缩波纹通道内脉动流动与换热情况，流动Re数的范围为10~1000，Pr数为0.7。