頻率基準 的英文怎麼說
中文拼音 [bīnlǜjīzhǔn]
頻率基準
英文
frequency primary standard-
Based on the real situation of submarine and antisubmarine warfare ( asw ), according to the classical design theory of transducer or transducer array, a sonar will be researched and made, which has the feature of more wider bandwidth, more lower operating frequency, more lager radiation acoustic power, more farther operating distance, more higher researching efficiency and more higher directive accuracy
本文根據現代潛戰和反潛戰( asw )的實際情況,按照經典的換能器和基陣的設計理論,研製聲吶,旨在擴展其頻帶寬度、降低其工作頻率、增大其發射功率、擴大其作用距離以及提高其搜索效率和定向準確度。This is the basis for the well-known cesium clock, presently the standard of frequency and time.
這就是眾所周知的銫原子鐘的基礎,它是目前的頻率和時間基準。Fourthly, according with the analyzing of flow measurement, we research the main problems needed to be solve in the process of measurement, such as analysis and measurement of the internal resistance, selection of excitation frequency, stable signal datum mark and restraining common mode interference, restraining for serial mode interference and working frequency interference ; transporting and shielding the flow signal, constant current excitation and magnetic field equalizing, flow measuring
第四,根據對流量測量問題分析的,深入研究了設計過程中需要解決的主要問題。如內阻分析與測量;勵磁頻率的選擇;穩定信號基準點與抑制共模干擾;串模干擾與工頻干擾抑制;流量信號傳輸與屏蔽;恆流勵磁與磁場補償;流量測量點的選擇等。The assembly language program collects and processes the data real time. comparing kinds of method of filter and arithmetic of fft, the author select the fir filter to realize pretreatment of signal and radix - 2 fft to distill the characters of librations
通過對各種濾波方法和fft演算法進行比較,本套數據檢測和校準處理系統採用fir濾波對採集到的信號進行預處理,利用基2fft演算法來提取信號的頻率特徵。A new method for measuring the vibration of shadow mask without touch by detecting the light density with reflection type optical fiber sensor is presented. the measurement system based on the new method is designed to make the vibration measurement easier working, faster calculating, and get more precise results. it is an important measurement and analysis tool to improve the performance of shadow mask and display quality of cpt
本文提出了基於單光纖光強度反射法的非接觸式微振動測量系統的原理,並設計製造了該測試系統,探索出了簡單方便可靠的測量方法,能夠準確客觀地反映蔭罩振動的各項參數(各振動模的振動頻率、振幅、衰減時間) ,實現了測試裝置的簡便化和測試過程的自動化,為cpt張緊式蔭罩系統的性能改進與顯示質量的提高提供了有效的測試分析手段。Abstract : this paper first presents the general design framework of maintenance deployment system in wartime, and then studies the main design criteria : the whole responsiveness, component responsiveness and steadystate efficiency. based on the above, some basic deplyment forms are analyzed and the general design procedure is presented at last
文摘:給出了設計戰時維修資源設置系統一般框架,提出了設計準則:整體反應性、單元反應性和穩態頻率;並運用以上準則對我軍現實活動中採用的幾種基本部署系統形式進行了分析;最後給出了戰時維修資源部署系統設計的一般程序。This paper researches and analyses the developments of web technology and magnetostrictive transducers from world wide region. the paper also analyes the characteristics curve of magnetostrictive transducers based on its equivalent circuit and researches the method how to make sure its syntony frequency and its electric simulation network parameters. at the same time, by using jsp technology, a magnetostrictive transducer electric simulation application is designed based on b / s three - tier system structure. the experiment data is fitted by curve fitting module. the equivalent input impedance of it with stimulate loop is separated based on the results of curve fitting and the syntony frequency and electric simulation network parameters of magnetostrictive transducers is determined by the input impedance. the method presented in this paper can determine the syntony frequency and electric simulation network parameters of magnetostrictive transducers with a better accuracy than the testing method of syntony & anti - synton y. further more, jsp, the advanced technology at current, has been used to realize a magnetostrictive transducer web electric simulation system. the system has good human computer interface and the function of resource sharing and information publishing. the research of this paper and its achievements have some practical merits in the researchful and applied fields of magnetostrictive transducer
用java編程語言編寫的曲線擬合模塊,對輸入的實驗數據進行了最小二乘法的曲線擬合;根據曲線擬合結果可從帶激勵線圈的磁致伸縮換能器的輸入阻抗中分離出磁致伸縮換能器鐵芯在無激勵電流時由機械振動形成的等效輸入阻抗,並由此輸入阻抗確定磁致伸縮換能器的諧振頻率及電氣模擬網路參數。本課題提出的方法與傳統的諧振?反諧振法相比,能更準確地確定磁致伸縮換能器的諧振頻率及其電氣網路參數。同時,採用當前比較先進的web技術,實現了基於jsp的磁致伸縮換能器web電氣模擬系統,該系統具有良好的人機界面和資源共享、信息發布功能。From the result we get the following conclusion : for narrow - band signal, the effect of the method based on fft is best. for wide - band signal, when snr is up to certain degree ( higher than - 7db or so ), the curves of square error of modified methods are more obvious and closer to crb. for an echo composed of more than one frequency or direction, space - frequency distribution could show more direct information of frequency and direction, which is more advantaged to make precise judge and estimation for doa of echo
從估計結果發現,對于窄帶回波信號,基於fft的方法估計性能大大優于其他方法;對于寬帶回波信號,在信噪比達到一定程度(高於約- 7db )時,補償后的幾種估計法的性能改善均比較明顯,誤差曲線越來越接近crb曲線;對于回波中存在多頻率多方位的情況,空間?頻率分布圖能提供較為直觀的頻率及方位信息,因此應用空間?頻率估計法來進行方位估計,更有利於進一步對回波的具體方位進行準確判斷和估計。In the end, the main content of this dissertation is addressed. in chapter 2, based on the analysis of present vibrator ' s principle and structure, two kinds of transfer functions and frequency response curves of the vibrator, driven by voltage feedback power amplifier and current feedback amplifier, are given separately. and turnover frequencies between different frequency rangs are also given
第二章分析了標準振動臺的工作原理和結構,在此基礎上,建立了標準振動臺的機械和電氣方程,給出了恆壓源和恆流源功放激勵下的振動臺傳遞函數及幅頻、相頻特性曲線,列出了不同頻段間的轉折頻率。The 33250a tcxo timebase gives you frequency accuracy of 1 ppm for your most demanding applications
33250a tcxo時基可達到1ppm頻率準確度,從而適應有最嚴格要求的應用The basic calibration of a rf signal generator normally includes tests on output level accuracy, level flatness, and frequency accuracy
射頻信號發生器的基本校正工作一般包括測試輸出電平準確度、電平不平坦度及頻率準確度。A new harmonic analysis method for electric power systems based on triangle basis functions neural network was presented, the convergence theorem of the algorithm was proposed, and a window function and interpolation algorithm were employed to correct the frequency of fundamental waves
摘要提出了一種新的基於三角基函數神經網路的電力系統諧波測量方法,給出了該神經網路演算法的收斂定理,並採用加窗插值演算法修正基波頻率的準確度。The analysis results show that : the frequency characteristic curve assumes the downtrend, so the electrical energy measurement of the induction meter will produce biggish error when the content of the harmonic is big, no matter taking the whole energy as measurement standard or basic wave energy
研究分析結果表明:感應式電能表的誤差頻率特性曲線呈迅速下降趨勢,因此在電能計量中,不管是以全能量為計量標準還是以基波能量為計量標準,當諧波含量較大時對感應式電能表的電能計量將會產生較大的影響。The concept of " timing " in the article is not the clock in our ordinary living, but syntheses which is made up of some frequency source in the signal generator ( such as cs atom frequency standard, rb clock & high accuracy quartz crystal oscillator ) which produces the primary frequency, the matching input interface and the matching output interface and controlling circuit etc. for example, bits is a kind of timing equipment, which is used to control the timing of some functions
本文論及的「時鐘」概念不是指日常生活中使用的鐘表,而是由產生基準頻率的信號發生器(如銫原子頻率標準、銣鐘及高精度石英晶體振蕩器等)中的某種頻率源以及相配套的輸入、輸出介面和控制電路等組成的一整套具有特定同步定時功能的綜合體。如bits就是一種時鐘設備,它提供用在通信系統中控制某些功能的定時的時間基準設備,時鐘提供的信號稱為基準信號、定時信號或同步信號。Time and frequency standards
時間和頻率基準External frequency reference option 001
外部頻率基準選件001Internal frequency reference
內部頻率基準Design amp; amp; preliminary results of nim cesium fountain primary frequency standard
銫原子噴泉頻率基準的設計與初步結果The 33220a external frequency reference lets you synchronize to an external 10 mhz clock, to another 33220a, or to an agilent 33250a. phase adjustments can be made from the front panel or via a computer
33220a外部頻率基準使您能同步于外部10mhz時鐘另一臺33220a ,或agilent33250a .相位調整可從前面板或通過This paper has presented the situation of intake silencer research and application and expounded the intake noise engendering cause and the basic theory on controlling the intake noise. then a research established in the accurate determination of resonance frequencies of different kind of helmholtz resonators is done. according to different assumptions, four kind of mathematical models are established, and the relations between them are discussed
本文介紹了進氣消聲器研究與應用的現狀與發展,闡述了進氣噪聲產生機理及控制的基本理論,研究了helmholtz共振型進氣消聲器的原理,立足於helmholtz共振型進氣消聲器的共振頻率的準確確定,建立了兩類四種共振腔模型,並討論了它們之間的相互推演關系。分享友人