Effective air handling and regeneration system is needed to wipe off harmful impurity inside enclosed space and to maintain required air purity and necessary gas element since the air inside the enclosed space can't exchange with the atmosphere.

On certain degree, it may be said that landscape poems were born out of poems of metaphysics, which gave the former the air of purity, and the thinking of Lao Tsu and Zhuang Tsu made people yearn towards the nature.

在一定程度上可以说玄言诗孕育了山水诗。玄学使山水具有清越之气，老庄思想使人们向往自然。

Application and management of air purity technique in operation room

空气洁净技术在手术室的应用及管理

A Comparative Study on Air Purifications by Effective Purity Ventilation and by Ultraviolet Irradiation

有效清洁自然通风与紫外线照射空气净化作用对比研究

A frequency Synthsizer wtih high spectrum purity, low noise level and fast hoppingcapability is necessary in frequency hopping communication system.

在跳频通信系统中需要频谱纯度高、噪声电平低和具有快速跳频能力为频率合成器。

Dielectric Resonator Voltage Controlled Oscillators ( DRVCOs) are widely applied in microwave oscillators because of their excellent phase performance, spectrum purity and stability.

介质谐振器压控振荡器（DRVCO）由于其优异的噪声性能、频谱纯度和稳定度广泛应用于微波振荡源中。

The source consists of a microwave phase-locked loop and a new type of automatic frequency control circuit. Chief factors to influence spectrum purity of microwave output signal and phase noise are analyzed.

该稳定本振源由一个微波锁相环路（PLL）和一种新型自动频率控制电路（AFC）组成，文中分析了影响微波输出信号频谱纯度和相位噪声的主要因素。

The Freguency Spectrum Purity Analysis for an Output Signal of a Digital Frequency Synthesizer

数字式频率合成器输出信号频谱纯度的分析

It leads to constant performance, higher spectrum purity and higher frequency stability.

实验结果表明，所研制的高精度频率信号源性能稳定、频谱纯度较高以及频率稳定度较高等优点。

The generation and real-time output of waveform data in segmentation make signals have better frequency resolution and spectrum purity than traditional frequency synthesizing.

同时采用分段产生波形数据实时输出信号的方式，使得频率分辨率和输出频谱纯度比之传统的数字频率合成更优越。

PLL has excellent character of narrowband slot, making locked frequence has the same frequence stability and spectrum purity, and has excellent performance spur reduction.

锁相环有良好窄带跟踪特性，使被锁定的频率具有与参考频率一致的频率稳定度和频谱纯度，对杂散的抑制性能良好。

The frequency synthesizer is the critical part of the transceiver, because it could meet the high requirement for the frequency stability, spectrum purity, frequency range and the number of output frequencies.

而频率合成器是射频收发机中的关键部分，它能满足对频率稳定度、频谱纯度、频率范围和输出频率个数等的较高要求。

To increase the DDS spectrum purity, the non-idea SCMP was optimized.

为进一步提高DDS的频谱纯度，可以对非理想SCMF误差进行优化。

The paper discusses on DDS spectrum purity improvement, and gives the circuit scheme.

对如何提高DDS输出频谱纯度进行了探讨，并给出电路解决方案。

Project of the fine spectrum purity signal source

一种高频谱纯度合成信号源实现方案

A frequency synthesizer with low phase noise, high spectrum purity and rapid frequency agility for a phased array radar is describe.

讨论了用于相控阵雷达的低相位噪声、高频谱纯度、快速频率捷变的频率综合器。

As the performance of electronic equipments is going up continuously, it comes up with higher requires at frequency, spectrum purity and tuning of microwave signal ( MS).

随着各种电子设备性能的不断提高，对微波信号源的工作频率、频谱纯度、可调谐性等性能提出了更高的要求。

IR Spectrum Determination of Purity of Industrial Benzohydroxamic Acid

红外光谱法测定苯甲羟肟酸的纯度

The phase noise is not only the main specification for the signal generators of the radar, communication and ECCM, but also the main basis to measure the spectrum purity of the frequency synthesizer.

相位噪声是雷达、通信、电子对抗等装备中发射源的主要技术指标，也是衡量频率合成器信号纯度的主要依据。

Radioactive purity of the solution is analysed by HPGe γ-spectrometer.

用HPGeγ谱仪分析测定了放射性纯度。

Value Stream Maps help us bring about organizational improvement, progress in our processes and methods, and most importantly, better software.

价值流图帮助我们给公司带来一些改进，过程及方法上进行升级，而更重要的是，生产质量更高的软件。