查询词典 coefficient of diffusion

Ice/ridge geometric parameters is established, and from computational analysis it is found that the unmonotonous variations of drag coefficient with ice concentration that frequently observed in sea ice field investigation mostly result from the influence of form drag from ice edge.

通过将原型条件下的冰-水总拖曳力考虑成表面摩拖曳力、冰侧形拖曳力和冰脊形拖曳力三部分，建立了冰-水总拖曳系数同海冰和冰脊几何形态参数之间的定量关系，并由计算分析发现现场观测到的拖曳系数随密集度的非单调变化就是冰侧形拖曳力分量作用的重要体现。

Compared of the efficiency of treating heavy metals in FGD wastewater with NaOH, Ca_2 and Mg_2. It indicated that NaOH was much efficient for precipitated waste water; Ca_2 was much efficient for unprecipitated waste water, the removal efficiency reached 98.4%. With the increasing of the main ion of Ca~2+, Cl~- in FGD wastewater, the efficiency decreased. It decreased 60% for the removing of Mn and 10% for Zn, Cd and Ni. The rectification coefficient token the Ksp of practical wastewater because it quite different with theoretic Ksp at different pH; the theoretic and practice addition were proportioned and it commonly reached 1:300.The precipitation efficiency of Na2S at different pH and the effect of Ca2+ was determined.

比较了NaOH、Ca_2和Mg_2处理脱硫废水时重金属的去除效果，分析了Ca~(2+)、SO_4~(2-)和Cl~-等主要离子的影响，结果表明：NaOH和Ca_2能有效处理脱硫废水中的重金属；对澄清废水而言，NaOH效果较好，对于未澄清废水而言，Ca_2效果更好，但去除废水中重金属的效率都能达到98.4%；随着Ca~(2+)、Cl~-等主要离子浓度的增大，中和作用去除重金属的效率降低，Mn最大降低60%，Zn，Cd，Ni降低10%左右；实际重金属浓度和用理论Ksp计算所得值差别很大，通过校正系数能有效计算实际重金属浓度；实现相同pH时氢氧化物的理论和实际投加量成一定比例，最大可达1：500。

However, a kind of saturable absorption effect has been introduced in unpumped EDFA based on the absorption of the Erbium system which means a lower absorption coefficient in higher intensity.

但是未泵浦的EDFA由于铒离子系统的吸收作用存在一种饱和吸收现象，这种饱和吸收作用使得未泵浦的EDFA在一个高光强下有很低的吸收系数。

With the support of a major research grant of Zhejiang Province (No. 001101027) and the Plan of Promoting Education of Excellence of Zhejiang University in the 21st Century, this dissertation is devoted to address the above problems and fabricate an L-band EDFA with low cost, high performance and technological innovation.First the mechanism of an erbium doped fiber amplifier is introduced. Various theoretical models based on classical rate propagation equations are summarized and compared for their applications. We use a modified numerical model based on the Giles model, which agrees with the experimental results well. This serves as the theoretical base for the whole thesis and will be used to optimize the characteristics of EDFAs. A novel method based on a map of noise figure and gain is proposed to analyze efficiently the dependence of the noise figure and gain for EDFAs on the EDF length and the pump power. The characteristics of various EDFAs are studied and compared.Secondly, some important parameters are introduced to describe the characteristics of EDFAs. The methods and the experimental setups for measuring the gain and noise figure of an EDFA are emphasized. We introduce how to measure the characteristics of each component of an EDFA, especially the gain and absorption coefficient of an erbium doped fiber.Thirdly, four types of simple and novel L-band EDFA structures with low noise, high gain and low gain ripple are proposed to satisfy the requirement of a DWDM system. They can be classified into two categories. In the first category, a single ASE pumping is served asa secondary pump. This category includes the following three types. Type: a new construction using a fiber Bragg grating in an unpumped EDF section at the input side. Type: a new structure of L-Band EDFA with two-stage pumps, which utilizes the forward ASE as a second pump.

本论文本着科技创新、服务于生产实践的精神，以设计价格低廉，性能优越、结构合理简单的L-band EDFA为目标，依托浙江省科技厅重大科学基金资助项目(001101027)和浙江大学振兴教育计划资助的全光网络的搭建—《光通信技术》课程实验建设项目，展开了如下工作：首先，介绍了掺铒光纤放大器的工作原理，归纳总结了基于速率方程基础的EDFA的各种理论模型，分析比较了各个模型的特点和适用场合，最终选择完善的Giles理论模型作为本论文分析设计EDFA的理论基础；针对实际实验条件提出了修正的EDFA模型的数值计算方法；创新地提出了增益—噪声系数全局分析法，直观有效地分析了EDFA的增益和噪声系数与掺铒光纤长度和泵浦功率的依赖关系，并对各种EDFA的性能作了全面的比较；第二，介绍了掺铒光纤放大器特性参数的定义与测量方法，重点介绍了噪声系数和增益系数的测量方法及实验装置；介绍了组成掺铒光纤放大器各组件的特性测量方法，重点介绍了测量掺铒光纤参数的方法和实验装置；第三，针对WDM系统对L-band EDFA谱平坦、低噪声、高增益的要求，我们创新地提出了四种不同的L-band EDFA结构，按设计思路可以分为两大类：一类是基于单抽运二级泵浦法，这一类包括在未泵浦掺铒光纤的输入端插入一根布拉格光纤光栅的两段L-band的EDFA的新结构；基于前向ASE光作为二级泵浦源推动下一级EDF工作的泵浦分配、两段级联L-band的EDFA的新结构；基于单根光纤光栅、泵浦分配、两段级联的EDFA；另一类则是基于同时应用前后向C-band ASE作二级泵浦源的双抽运法，如基于前后向ASE光作为二级泵浦源的三段级联L-band的EDFA的新结构。

3In the normal space tensile,after controling the influence of density, the variation ofmicrofibril angle had a decisive effect on L MOE and longitudinal tensile strength of D333A wood microtome section; the Correlation coefficient between microfibril angle and L MOE became significant at 0.05 level for D1123A wood microtome section; the Correlation coefficients were all unsignificant between microfibril angle and L MOE and between microfibril angle and longitu- dinal tensile strength to D1223A wood microtome section.

正常间距拉伸中，控制密度的影响后，微纤丝角的变化对D333A组微切片纵向MOE和抗拉强度的变化起着决定性作用；对D1123A组微切片纵向MOE的相关系数达到0.05水平上显著；对D1223A组微切片纵向MOE和抗拉强度都成负相关关系，但都达不到显著水平。

Grain yield per hectare is the most important factor in the method of the gray system analysis. There was significant correlation between effective irrigated area, the amount of fertilizer applied, mechanical power and the grain yield. The area of grain and the population of agriculture are factors that affect grain production. The correlation coefficient of natural resources and grain production changes unstably.

单产与粮食产量始终保持很高的关联度；有效灌溉面积、实际机耕面积、化肥施用量、农村用电量和农机总动力等农业投入对粮食产量提高影响重大；耕地面积和劳动力对粮食产量具有一定的制约；自然条件与粮食产量的关联度剧烈变动。

The study compares the Seebeck coefficient in the amino-substituted and unsubstituted butanethiol junction and observes interesting thermoelectric properties in the amino-substituted junction.

在利用butanethiol为实验对象下，我们发现有用氨基取代的butanethiol和没有取代的butanethiol，它们的Seebeck 系数会呈现非常大的不同。

For the same Reynolds number the average heat transfer coefficient of the twisted duct is almost the same as that of the untwisted one.

在相同Re下平均换热系数几乎与不扭转通道相同。

Through the test of 8 RC shear wall specimens and the computer analysis of the strains of steel bars with keyways in the spccimens, the authors have studied the remains of tensile stress of concrete between cracks after cracking and put forward a formula to calculate coefficient ψ, the ununiform distribution factor of steel strain.

本文通过8片剪力墙板的试验，用计算机对各级荷载下钢筋连续应变值的分析，找出了钢筋混凝土剪力墙板开裂后裂缝间混凝土受拉性能的变化规律。给出了钢筋应变不均匀系数ψ的计算公式。

An analysis is also made of the moving regular of particles, the leakage passage formation feature, and the particles displacement field and so on. The internal stability of soils is studied from the perspective of gradation. Results show that the stability of soils relates closely to the shape of gradation curves and coefficient of ununiformity.

研究得到管涌发展过程中颗粒的移动规律，渗漏通道的形成特点，流速、颗粒位移场等随水力梯度的变化特点，并从级配角度分析土样的稳定性，得到土体的稳定性与级配曲线形状及不均匀系数等因素有关的结论。

Salt is good, but if the salt becomes flat and tasteless, with what do you season it?

14：33 盐本是好的，盐若失了味，可用什么叫它再咸呢？

He reiterated that the PLA is an army of the people under the leadership of the Communist Party of China.

他重申，人民解放军是在中国共产党领导下的人民军队。