数值技术

For the parison forming , the explanation had been given about method and theory basis of numerical simulation adopted by researchers at civil and abroad, and the method of neural net was review empnatically.

介绍了模拟技术在吹塑型坯成型中的研究和发展状况，针对型坯成型过程，对国内外学者进行数值分析的方法和理论依据进行了论述，着重论述了神经网络方法。

As one kind of means for quantitive forecast and analysis, the numerical simulation technique can provide necessary theory basis and guidance scheme for the implement of this technology.

作为一种定量预测、分析手段，定向羽状水平井开采的数值模拟可为该技术提供必要的理论依据和指导方案。

The longitudinal vortex generator is a new technique of enhanced heat transfer,this paper presents the effects of the longitudinal vortex in horizontal rectangled duct on the heat transfer coefficient and pressure drop.

纵向涡是一种新型的传热强化技术，其传热性能好，安装方便，使用可靠。以数值计算方法分析了在常壁温条件下纵向涡对换热器的传热性能以及流动阻力的影响。

Fortunately, the modern geodetic measurements such as the Global Positioning System technique can overcome the shortage of the geological and seismographic methods in the time dimension; and yet, the coverage of the geodetic survey stations is not sufficient. As a result, it is necessary to employ numerical simulation to investigate the continuous deformation of the crust.

而以全球定位系统等技术为主的大地测量方法弥补了地质和地震学方法在时间维上的不足，但大地测量方法存在测点覆盖不足及测点地理分布不均匀的缺点，因此，要得到连续的地壳形变场有必要借助数值模拟方法。

In addition, the anomaly law of the advanced detection of water-bearing structures with other shape is studied; and concept of equivalent sphere is raised. A fast inversion method is designed on the base of the analytical formula of the spheriform structures detection in the whole space.

最后，利用物理模型试验验证了有限元数值正演方法和阻尼最小二乘反演技术的可行性和有效性，为实际工程中含水构造的直流电法超前预报奠定了基础。

Objective To investigate the feasibility of using CT image-based computational fluid dynamics to simulate numerically the local hemodynamics in anatomically realistic human stenosed carotid bifurcations.

目的探索以CT图像为基础构建动脉血流动力学模型的技术方法，对颈动脉狭窄局部进行计算血流动力学（computationalfluid dynamics，CFD）数值模拟。

Variabilis natural type; applied the theory of numerical taxology and cluster analysis method, classified the Q. variabilis of Qinba and Huanglong mountain; ascertained the standard and method of Q. variabilis plus trees selection about 30 ages in Shaanxi province different areas and selected 49 plus trees that were suitable to different areas; used isoenzyme analysis ,through the detection enzyme system of POD,GDH,EST and ADH ect, researched the genetic variation level of Q. variabilis natural populations and heredity construction of different Q. variabilis natural type .The result showed:(1) Q.

本文通过对栓皮栎地理分布的研究，确定了研究栓皮栎天然类型的地理区域；应用数值分类学原理，采用聚类分析方法，对秦巴山区和黄龙山区的栓皮栎天然类型进行划分；确定了陕西省不同地区30年左右栓皮栎优树选择的标准和方法，并选出了适宜不同地区生长的优树49株；采用同工酶技术，通过对POD、GDH、EST、ADH等4个酶系统的检测，研究栓皮栎天然群体遗传变异水平和不同栓皮栎天然类型的遗传结构。

The definition and evaluations and characteristics of equivalent loads of unbonded prestressed tendons are discussed by using the free-body method.

应用脱离体的方法对无粘结预应力筋的等效荷载的定义、荷载数值的确定、等效荷载的特性进行了讨论，并据此分析了预应力技术在工程应用中涉及的若干概念问题

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。

This paper deals with a lump-sum flow analysis of a spiral case, stay ring and vaneless annular walls for a small Francis tu...

本文对常用的小型混流式水轮机涡壳、座环和无导叶环壁面内流动状况用最新的 CFD技术进行了整体数值解析。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。