查询词典 pumps

About 20 percent of the oil wells use rodless botttom hole pumps to exploit.

大概有20%的油井使用无杆泵采油技术。

It is widely used in steel metallurgy industry,such as bushes for foller grooves of successive casting machines,cement grouting pumps and scrow conveyers of machine.

铜具有自润滑性能，可用于长期运作而无法停机检修的部位。

Sealless pumps were used for many application including handling abrasive, corrosive and foul liquids

无密封的磁力泵可以应用在研磨剂的，腐蚀的和污秽的液体

MPT Series magnetically driven, sealless regenerative turbine vane pumps are designed specifically for small flows at high heads.

MPT系列，磁力驱动的回热式透平泵，专门用于小流量，高压头应用领域。

Magnetic coupling is a new kind of coupling,which connects motor and machine by permanent magnetic force.They work in the sealless magnetic drive pumps,which transporting volatile,flammable,explosive and toxic solutions with no leakage.

它无须直接的机械联接，而是利用稀土永磁体之间的相互作用，利用磁场可穿透一定的空间距离和物质材料的特性，进行机械能量的传送。

More, this study was useful for the inner flow field and force analysis of other slantwise pumps.

该项研究对其它斜式泵的内部流态及受力分析也是一个很好的借鉴。

More, this study wasuseful for the inner flow field and force analysis of other slantwise pumps.

该项研究对其它斜式泵的内部流态及受力分析也是一个很好的借鉴。

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 simultaneously pumps up asset prices and obscures their speculative nature, with euphoria usurping the place of analysis.

这在推高资产价格的同时还模糊了它们的投机本质，狂热篡夺了冷静分析的位置。

The just working frequency was obtained by calculation. By transient dynamics analysis applying piezoelectric coupling theory, the transient dynamics properties have been discussed. The analysis result provided a design reference on this kind of valveless piezoelectric pumps that use Cymbal actuators.

通过模态分析得到了Cymbal振子的前5阶固有频率和振型，选出其中最符合工作要求的频率和振型；通过瞬态分析，结合压电耦合分析，得到了振子在方波电压作用下的瞬态动力学特性。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。