波长

The study indicates that the center wavelength of FBG's reflected spectrum on the two polarization directions shift, and the reflectivity decreased with the increase of the twist angle. The longer wavelength produces"red shift". The shorter wavelength produces"blue shift". And the wavelength shift is basically same.

研究表明，随着扭转角度的增加，两个偏振方向的光栅反射谱中心波长发生移动且反射率降低，长波长的产生"红移"，短波长的产生"蓝移"，移动的波长量基本相同。

And, to get correct wavelength data, Burleigh WA-4500 wavelength meter was used. With the efforts on hardware connection and software programming, the data was transported from WA-4500 to the main control computer through RS232 serial communication.

为了得到激光波长的准确数据，本文使用了Buileigh公司的WA-4500波长计，并利用RS232串口把其波长数据传输到主控计算机，完成了串口硬件连接和通信软件编制。

The first disadvantage of MMI device is wavelength sensitive, which leads to restricted applications. To reduce the wavelength insensitivity in optical network applications, the demand of light source with a specific wavelength is needed, especially for power splitters. For this reason, a wideband criterion for MMI splitter is proposed. The basic principle is based on reducing the interference length difference and making it shorter than the spot size for constructive mode interference. Simulation results show the spectra of proposed MMI splitter is wide enough (1.26-1.61um) to cover the fiber communication band and the size of the splitter is more compact than that of the conventional MMI or Y-branch splitter.

多模干涉元件的第一个缺点为波长敏感，此缺点会限制其在实际上的用途；因元件在网路上的应用时，通常都需要降低波长敏感性，以减低对光源波长准确性的要求；有鉴於此，本论文提出多模干涉分光器的宽频标准；基本原理是建立在缩短其多模干涉区的长度差，并使之小於建设性干涉的光点大小；透过模拟后发现，操作频宽可涵盖光纤通信全波段(1.26-1.61um)，且长度小於Y形分支结构的分光器。

Between 1/4 and 1/2-wavelength spacing the pattern narrows, but side lobes (interferencepatterns, caused by destructive interference) do not appear until the spacing is greater than 1/2 wavelength.

在1/4波长和1/2波长之间是不会出现旁瓣（副极大值，干涉波形，通常是由破坏性的干涉导致）的，这一现象会持续直到间距大於1/2波长。

METHODS:Using Dual-wavelength TLC-scanning,the sample was prepared through the column full of D101 macroporous resin with n-butanol extract from the aque ous solution of the granules which had been washed by ether,developer is chloroform-methanol-water(13∶10∶7)(stored at less than 10℃,the lower),detecter is 510nm,reference is 700nm.

双波长薄层扫描法，经乙醚洗涤、正丁醇提取和D101大孔吸附树脂柱层析法制备样品，以氯仿-甲醇-水(13∶7∶2)下层液为展开剂，检测波长为510nm，参比波长为700nm。

The definition of the definition of wavelength wavelength wavelength ----: along the direction of wave propagation in the wave graph position of relative equilibrium displacement of the adjacent same time the distance between two particles.

波长的定义波长的定义----波长：沿着波的传播方向，在波的图形中相对平衡位置的位移时刻相同的相邻的两个质点之间的距离。

When proceeding the research of drug identification by ultraviolet spectrophotometry, this paper adopts the approaches below: to identify Metronidazole Buccal Tablets and Potassium Sodium Dehydroandroan Drographolide Succinate by ulviolet maximum absorbent wavelength; to identify Metronidazole Disodium Phosphate for Injection by ulviolet maximum absorbent wavelength and minimum absorbent wavelength; to identify Ceftriaxone Sodium for Injection and Clarithromycin Tablets by retention time of high performance liquid chromatography- ultraviolet spectrophotometry.

通过测定紫外最大吸收波长λ_(max鉴别甲硝唑口颊片和炎琥宁、测定紫外最大吸收波长λ_(max和最小吸收波长λ_(min鉴别注射用甲硝唑磷酸二钠，结合高效液相色谱(high performance liquid chromatography-ultraviolet detector，HPLC-UV)中保留时间的测定鉴别注射用头孢曲松钠和克拉霉素片，本文建立了药物鉴别的紫外分光光度法。

The method of selecting good wavelength data for building analysis model is an effective improving analysis precision.To quicken convergence, the piecewise wavelength selection method based on particle swarm optimization algorithm is established.

探讨了光谱信号定量分析中的波长选择问题，提出了基于粒子群优化算法的分段波长选择方法，以解决定量分析中波长选择的主观随意性和已有方法算法复杂、收敛慢的缺点。

The vapour and plasma ignition times of the target are got based on the equation of heat conduction and cascade model. We suppose that the plasma is ignited when 210 generations of new electrons are born in vapour generation time. The influence of temperature on the thermodynamics and optics parameters of material also have been considered in the model. The resulting theory has good agreement with the experiment and overseas report. A blade method to measure the laser spot is given in this paper with validation and error analysis. The plasma threshold of metals in atmosphere and water ambients both are diagnosed with the light deflection and piezoelectric transducer. A Q-switched pulsed Nd:YAG laser operating at infrared (1064nm), visible(532nm) and ultraviolet (355nm) wavelengths has been used. Al、Fe、Cu are used as targets and get a similar results with both method. Theoretical and experimental analyses are applied on the influence of wavelength on the threshold have been done, both of which have shown that the plasma threshold of metals decrease as the laser wavelength increases; The plasma threshold of metals are higher in water than in air and the pressure of the shock wave in water is five times higher than in air.

从热传导方程和雪崩电离机制出发，假设当电子增值2~(10)倍时，考虑了温度对材料热力学和光学参数的影响时，得到了气化和等离子体点燃的时间，利用该模型进行计算得到的结果与国内外报道及自行通过实验测得的阈值基本一致；提出了利用刀刃法测量激光光斑面积的方法，并通过实验进行了验证和误差分析；利用光偏转装置和压电换能器分别对空气和水中金属等离子体点燃阈值进行了实验诊断，激光器均为调Q—YAG激光器(波长1064nm，532nm，355nm，脉宽10ns)，靶材分别为Al、Fe和Cu，两种测试方法得到的等离子体点燃阈值基本一致；本文从实验和理论计算两个方面讨论了波长对等离子体点燃阈值的影响，均得到了等离子体点燃阈值随着波长的增加而减小的结论；对空气中和水中不同环境下金属等离子体的点燃阈值进行了比较研究，得到了金属在水中的等离子体点燃阈值比空气中的大，且水中产生的冲击波的压强是空气中的5倍左右的结论。

Then find out that ethyl ether can absorb the UV-light, the wavelength of that is lower than 304 nm, and can produce strong fluorescence.

发现，乙醚能吸收波长小于304 nm的紫外光，产生强的荧光；乙醚的荧光峰是波长306 nm至345 nm范围的宽谱峰，峰值波长在317 nm左右。

Do not gum up the work by telling mother what we are going to do .

别告诉母亲我们要干的事，那会把事情搞糟的。

In recent years, application of the partial prestressed concrete beam s is developed.

近年来，随着部分预应力砼梁应用的推广，发现我国规范所采用的名义拉应力法的计算结果不稳定。