低技术的

along with the development of digital technology,digital filters are widely used in many fields,this paper introduces how to design a iir digital notch filters in matlab environment.the design of digital notch filters can be achieved through three steps:firstly,the design of analog lowpass filter; secondly,it is analog lowpass to analog band stop filter conversion;at last,using the bilinear transformation make the analog notch filters change into digital notch filters.the paper also introduces how to design the transfer function of the digital notch filters using all the zeros and farthest points at the same time,it also introduces the program of the digital notch filters under butterworth analog lowpass prototype.

摘 要：随着数字技术的发展，数字滤波器在许多领域得到广泛的应用。研究一种在matlab语言环境下设计iir数字陷波滤波器的方法，在数字陷波滤波器设计过程中，先进行模拟低通滤波器的设计，然后进行模拟低通/模拟带阻滤波器转换，最后采用双线性变化法将模拟陷波滤波器转化成数字陷波滤波器。提出一种用所有零点和极点来表达数字陷波器传递函数的方法，同时给出以巴特沃斯模拟低通为原型设计数字陷波滤波器的程序。关键词：无限冲激响应；巴特沃斯滤波器；数字陷波滤波器；matlab；双线性变换

The key features of Bluetooth technology are robustness, low power, and low cost.

蓝牙技术的主要特点是稳健、低功耗、低成本。

Bluetooth is a low cost, low power, short distance wireless communication technology.

蓝牙是一种低成本低功耗的短距离无线通信技术。

In the first chapter, the class of modern frequency composing techniques and the recent development situations have been introduced. Then the advantages and disadvantages of the techniques have been described. At last, based on the techniques mentioned above, a scheme to realize the X-band low phase noise frequency source has been proposed.

在第一章引言部分，主要介绍了现代频率合成技术的分类及技术发展近况，并就每一种合成技术的优缺点做了简要的陈述，最后以上述不同合成技术的优缺点为基本指导思想，提出了一种实现X波段低相噪频率源的方案。

ABSTRACT Over the last few years much attention has been paid to the development of the technologies for Community Antenna Television networks. New technologies that can be used to support data communication service over CATV networks are developed. The new Hybrid Fiber Coaxial technology is spreading out rapidly in CATV networks. The usage of fiber provides large bandwidth and thus enables some new services to be delivered along with television broadcast. The CATV networks are expected to support diverse traffic with various service requirements.

随着新技术的不断发展，人们希望能够利用有线电视网络提供新的业务，HFC技术在有线电视网络中的广泛使用使得有线电视网络的带宽增加，也使得有线电视网络除电视广播外还能够提供其他的服务，这些服务的服务质量要求各不相同，如：数据服务要求低的丢失率，对延时的要求较低；而语音服务可容忍一定的丢失，但对延时、延时抖动有严格的要求，因此需要开发新的协议。

Information technology project is the "number one project", but China's real estate business in general there is no specific person in charge of information technology, and now many companies are only temporary in the office and other non-information technology sector following the appointment of a computer management staff to be responsible for such work, enterprise senior general on the importance of information technology are relatively low.

信息技术项目的"头号工程"，但中国的房地产企业一般没有具体负责人，信息技术，现在很多公司都只是暂时的在办公室和其他非信息技术部门在任命计算机管理人员来负责这项工作，企业高级关于信息技术的重要性相对较低。

Company and the Chinese Academy of Sciences Institute of Chemistry, Nanjing University of Technology Institute of Chemical Technology has a good technical cooperation, product quality can meet the needs of different customer requirements, in particular, high content, low-arsenic, low lead, low-iron phosphorus trichloride, oxychloride P-selling more than a dozen provinces and cities nationwide, autonomous regions and exported to Europe, Southeast Asia and Taiwan, production and sales and market share in the same industry in the country ranked the top three, Jianping people adhere to the "credibility first, customer first, service first" operating purposes, warmly welcome customers at home and abroad to discuss cooperation with our company.

公司与中科院化学研究所、南京工业大学化工学院有着良好的技术合作，产品质量能满足不同客户的要求，尤其高含量、低砷、低铅、低铁的三氯化磷、三氯氧磷畅销全国十几个省市、自治区及出口到欧洲、东南亚和台湾地区，产销量和市场占有率在全国同行业中居前三甲，建平人恪守"信誉第一、顾客至上、服务至上"的经营宗旨，热忱欢迎国内外客户与我公司洽谈合作。

Company and the Chinese Academy of Sciences Institute of Chemistry, Nanjing University of Technology Institute of Chemical Technology has a good technical cooperation, product quality can meet the needs of different customer requirements, in particular, high content, low-arsenic, low lead, low-iron phosphorus trichloride, oxychloride P-selling more than a dozen provinces and cities nationwide, autonomous regions and exported to Europe, Southeast Asia and Taiwan, production and sales and market share in the same industry in the country ranked the top three, Jianping people adhere to the "credibility first, customer first, service first" operating purposes, warmly welcome customers at home and abroad to discuss cooperation with our company.

公司与中科院化学研究所、南京工业大学化工学院有着良好的技术合作，产品质量能满足不同客户的要求，尤其高含量、低砷、低铅、低铁的三氯化磷、三氯氧磷畅销全国十几个省市、自治区及出口到欧洲、东南亚和台湾地区，产销量和市场占有率在全国同行业中居前三甲，建平人恪守&信誉第一、顾客至上、服务至上&的经营宗旨，热忱欢迎国内外客户与我公司洽谈合作。

Organic light-emitting diodes are interesting candidates for prospective electronic devices in the field of flat-panel display technology, because they have advantages such as self-luminescence, low operating voltage below DC 5.0 V, high luminance and efficiency, broad viewing angle, short response time, etc.

OLED器件（Organic Light-emitting Devices）以其质轻、体薄、高亮度、自发光、快速响应、高分辨率、视角大、低电压驱动、低功耗、高效率、长寿命等突出优点被认为是下一代显示技术的最佳候选。

This paper attempts to associate PFC technology with Quasi-Resonant DC/DC Converter and Synchronous Rectifier technology, to work out a novel switching power supply with higher efficiency and low contamination, which both achieved high power factor, improved effecting on electrical network and ensured high efficiency, furthermore, it is easy to be realized and controlled in circuit.

本文首先阐述了开关电源、功率因数校正技术和同步整流技术的发展及现状，对DC/DC变换的拓扑结构进行了选择，确定了带有隔离的准谐振(Quasi-Resonant)反激型电路，可以有效地降低损耗；接着本文对几种常见的PFC拓扑电路进行分析对比，从中选择了BOOST型电路，对工作在临界状况下的电路进行了分析，采用跟随输入电压的升压变换新技术，减小了电感体积，同时降低了开关管的电压应力，既简单又有效地实现了功率因数校正，并发现此技术值得推广；由于反激型变换器的效率一般都较低，所以本文在传统同步整流技术基础上对其加以改进，设计出一种新颖、高效的同步整流方案。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。