腔形成

The research which is the important part of the tunable erbium-doped fiber laser is composed of two main parts: 1. the gain part of the tunable erbium-doped fiber laser, which in fact is an erbium-doped fiber amplifier, its output characteristics are discussed both in theory and experiment, and the differences are also discussed between theory and experiment; 2. the saturated absorber part of the tunable erbium-doped fiber laser, also the part to narrow the line width of the fiber laser. The line-width narrowing mechanism in fiber laser induced by unpumped Er-doped fiber is presented from the aspect of coupling wave equation, and the main factor is considered as the standing wave induced by interference. The line-width is narrower when the standing wave is stronger, and the narrowing effect disappears with the disappearance of the standing wave. In the experiment, when adding a Faraday mirror in the laser cavity to remove the standing wave , the narrowing effect disappears. So the theory is proved by the result of the experiment.

本课题的研究内容是集成光学声光可调谐掺铒光纤激光器的重要组成部分，主要分两部分：1、声光可调谐掺铒光纤激光器中增益部分的研究，相当于对掺铒光纤放大器的研究，理论上对掺铒光纤放大器的输出特性进行分析，实验上实现了掺铒光纤放大器系统，并将实验数据与理论计算数据进行对比，分析了误差产生原因；2、声光可调谐掺铒光纤激光器中饱和吸收体部分的研究，即压窄光纤激光器输出线宽的研究，从耦合波方程出发，理论上解释了未泵浦掺铒光纤压窄光纤激光器线宽的原理，分析了影响该作用的主要因素是未泵浦掺铒光纤中相对传输的光干涉形成的驻波：驻波越强，压窄效果越好，相反当没有驻波时，没有压窄效果，在实验上通过在激光器腔内加入法拉第旋转镜使驻波消失，同时压窄效果消失，从而验证了理论分析的正确性。

To meet the needs, a novel low-noise fiber laser with compound cavity structure is designed. The stable single-mode operation is realized by using a transient self-written fiber grating, produced by the effect of saturable absorption within a section of unpumped erbium-doped fiber, as narrow band filter for mode selecting and linewidth squeezing. Through optical path modification, the spectral signal-to-noise ratio is better than 62 dB.

激光器采用复合腔结构，以掺铒光纤作为工作物质，通过在未被抽运的掺铒光纤中形成的瞬态自写入光纤光栅的窄带滤波特性进行选模和压窄线宽，产生稳定的单频激光输出；经过光路改进，激光输出光谱信噪比优于62 dB；利用光电负反馈电路，弛豫振荡峰下降了约25 dB，低频段强度噪声也大为改善，有效地抑制了光源的强度噪声。

To realize single longitudinal-mode of the fiber laser, a ring configuration is devised. The single longitudinal-mode operation is realized by using a fiber Bragg grating as wavelength-selective element and a unpumped 2m-loog erbium-doped fiber which can produce stading-wave saturation effects in the cavity, Its tunable wavelength range is 42 nm, the output power is more than 3.5 dBm and the stability is less than ±0.005 dB.

为了实现光纤激光的单纵模，提出了一种环形腔结构，采用可调谐光纤Bragg光栅作为波长选择器件，与2m未抽运掺Er光纤产生驻波饱和效应，在1.55m波长处形成42nm激光输出，输出功率大于3.5dBm，功率稳定性优于士0.005dB。

The cells were then maintained in culture flasks and further identified by immunofluorescence,immunocytochemistry,and vasculogenesis experiment.

结果兔外周血单个核细胞体外培养可成功获得内皮祖细胞，稳定表达内皮祖细胞相关抗原，并能在matrigel凝胶上形成稳定的血管腔样结构。

Here, we show that DEG5 and DEG8 form a hexamer in the thylakoid lumen and that recombinant DEG8 is proteolytically active toward both a model substrate and photodamaged D1 protein of photosystem II , producing 16-kD N-terminal and 18-kD C-terminal fragments.

我们研究发现在类囊体膜腔侧的DEG5和DEG8形成6聚体，重组的DEG8对于模式底物和光破坏了的光系统Ⅱ中的D1蛋白质都有蛋白酶解活性，可以将D1蛋白质剪切成N-末端16kD和C-末端18kD的片段。

Maintaining a glow discharge in said selected process chamber that partially ionizes said film forming material to form a film comprising silicon and hydrogen on said removed substrate.

在所述所选的工艺腔内保持辉光放电，以部分电离所述薄膜成形材料，在所述被取出的基片上形成含硅与氢的薄膜。

Maintaining a glow discharge in said selected process chamber that partially ionizes said film forming material to form a film comprising silicon and hydrogen on said first substrate; and

在所述所选的工艺腔内保持辉光放电，以部分电离所述薄膜成形材料，在所述被基片上形成含硅与氢的薄膜；并且

Discussion: About the knot formation, most authors believe that the more the catheter is advanced into the epidural space, the greater is the theoretical potential of "kinking and knotting" of the catheter.

讨论：关於打结的形成，大部份的作者都相信，如果导管进入硬膜外腔越多，理论上它产生纠结的可能性越高。

The residual lumen of the pouch is reduced to a narrow Rathke cleft, which generally regresses.

残留的腔隙形成一个狭窄的Rathke裂缝，通常会退变消失。

If one stamps on the congealed lava nearby, one will hear hollow thumps coming up from underground, as there is a huge cavity underneath caused by the crusting of the surface of the lava flow while it was still moving in molten form underneath.

在石龙脊上跺脚，能听到&空空&的声音，下面是一个巨大的熔洞。灼热的岩浆奔流时，外面的首先冷却结壳，而里面仍在流溢，这样就形成了巨大的空腔。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。