查询词典 coefficient of absorption

The calculated nonlinear absorption coefficient of BaTiO〓 is in good agreement with the experiment.

计算得到的BaTiO〓的非线性吸收系数和实验值符合的很好。

A theoretical method to calculate the absorption coefficient of the multi-layer absorber is proposed in this dissertation.

本论文基于主动吸声降噪的特点，围绕其若干关键技术问题，在理论和计算等方面进行了研究与探讨。

The result are as follows: because of the inner structure of WPC which has a large surface density has no lacuna or seriate hole, the sound absorption coefficient of wood plastic composites in frequency spectrum range from 0Hz to 1600Hz is low, Leaving a cavity or air interlayer behind the WPC board makes an "air-spring quality system".

造成吸声系数较低的原因是木塑复合材料的面密度较大，内部结构中没有微小的间隙和连续的孔洞。

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。

There exists a maximum for the amplification of high-power Stokes beam which is restricted by the energy of pump beam, the absorption coefficient of medium and the length of medium cell, etc.

通过优化介质池长和介质吸收系数等参量可以提高斯托克斯光放大的最大值，并获得较高的能量提取效率。

The prototype system considers the geometry of the building, the position of the source and receiver, and the acoustic properties of the sound transmission (the sound absorption coefficient of the walls and the temperature of the environment). The system then builds the beam tree by beam tracing, and finds all possible paths of the transmission and reflection. All sound paths are then traced to compute the sound obtained by the receiver.

本系统利用建筑物的几何空间、音源与接收者的资讯，考虑建筑材料的吸音系数、环境的温度等声学相关属性，使用光束追踪法建立光束树，寻找各种可能的穿透与反射路径，建立声音的路径模型，并且计算声音的衰减，处理声音的音响输出，来模拟接收者所听到的声音与回响。

The main reasons and its correlated factors of the photoacoustic signal had been quantitatively analyzed based on signal absorption and photoacoustic rationale. It is found that the changed coupling coefficient of sound source and optical cavity modes which caused by the intensity of incident light absorbed by gas sample is the major reason, and a criterion was put forward for signal saturation depth estimating.

基于气体吸收和光声光谱原理定量分析了光声信号饱和的主要原因及影响因素，分析表明气体样本对入射光强吸收而导致的声源与本征共振模式的耦合系数改变是异常饱和的主要原因，并导出判定光声信号饱和深度的准则以用于判定高浓度气体饱和深度。

With the numerical method, the influences of the offset of stronger light, probe-field strength and branching ratio coefficient of spontaneous decay from excited level to lower levels to atomic absorption are discussed.

借助于数值计算，讨论了较强光失谐、探针光强、激发能级向低能级衰减的分配系数对原子吸收的影响。

Nozzle flow was assumed to be frozen, and convective and radiative heat transfer from gas to solid wall was considered. Discretization of the governing equations was performed with two order upstream scheme, and radiative heat transfer equation was solved with Discrete Ordinates method. Absorption coefficient of water vapor was calculated by Leckner formula.

计算中，假定塞式喷管中的流动为冻结流动，考虑燃气向壁面的对流换热和辐射换热；采用二阶迎风格式离散控制方程，及DO模型离散求解辐射换热方程，水蒸气的吸收系数根据Leckner公式计算。

A new three-detector litho logy density tool appears. It can correct the influence of thin beds and obtain photoelectric absorption coefficient of formations more exactly.

於是，出现了一种三探测器岩性密度测井仪器，这种仪器可以对薄层进行校正并能更准确地求取地层的光电吸收截面系数。

Objective To investigate the effects of interleukin-1 β converting enzyme gene on the biologic characteristics of ovarian cancer cells.

目的 探讨白细胞介素-1 β转换酶的表达，对卵巢癌细胞生物学特性的影响。

Campylobacter: This illness is the most commonly identified cause of diarrheal illness in the world.

弯曲：这种病是最常见的原因查明腹泻病，在世界上。