standard frequency system 中文意思是什麼
standard frequency system
解釋
標準頻率系統-
Standard test method for impedance and absorption of acoustical materials using a tube, two microphones, and a digital frequency analysis system
管子雙擴音器和數字頻率分析系統用傳聲材料的阻抗和吸收的試驗方法 -
Doppler very high frequency omni - directional range and distance measuring equipment ( dvordme ) system standard icao radio navigational aids used to provide bearing and distance information to aircraft and to define air traffic control routes for en - route, terminal and instrument approachdeparture procedures
這是國際民航組織指定的標準無線電導航設備，可向航機提供方向及距離的資料，並可以確定航路、終端區程序、儀表進場及離場程序等。 -
This paper conbined with the indoor test and the scene test road, through the synthetical analysis of the factors of influencing densification effect for the densification thickness of filling stone roadbed. the maximum grain size of fill material, densification machinery and densification frequency et al. advanced a control norm of the maximum grain size and piy of compression, established ration evaluating the control standard of densification quality of filling stone roadbed under overload. comparing with result of indoor test and the scene test road, studied on theory of densification in different kinds of stone material and perfected the control system of the densification of filling stone roadbed under overload
結合室內試驗和現場試驗路的實測數據，通過對填石路基的壓實厚度，填料最大粒徑，壓實機械及壓實遍數等影響壓實效果的因素的綜合分析，提出填石路基的最大粒徑和攤鋪厚度的控制指標，建立定量評定超重載交通下填石路基壓實質量的控制標準，並對照室內試驗和現場試驗結果，研究不同石料條件下的壓實理論，補充完善了填石路基壓實控制指標體系。 -
On the basis of this theory, the applications of the sdr structure of wideband and bandpass sampling in if ( intermediate frequency ) in flight test were offered : increase the sampling in if ( intermediate frequency ) in flight test were offered : increase the capacity of the transmitter and the terminal receiver channels without changing the apparatus of original system and on the conditions of obeying the standard remote sensing
首先對軟體無線電的組成結構和飛行測試中實際使用的通道進行了闡述，在此基礎上提出了基於寬帶中頻帶通采樣軟體無線電結構在飛行遙測測試中的應用，在不改變原系統設備的情況下，在遵守遙測標準的前提下，提出增加機載發射機和接收機通道容量的設計方案。 -
The frequency - stability of an al ] - solid - state nd : yvo4 laser is significantly improved by means of a specially designed f - p interferometer used for the frequency standard in the frequency - stabilizing system
利用f ? p （ fabry - perot ）腔作為頻率參考標準的激光穩頻系統，是長期以來使用的一種簡單而有效的裝置。 -
A method that combines category - based and keyword - based concepts for a better information retrieval system is introduced. to improve document clustering, a document similarity measure based on cosine vector and keywords frequency in documents is proposed, but also with an input ontology. the ontology is domain specific and includes a list of keywords organized by degree of importance to the categories of the ontology, and by means of semantic knowledge, the ontology can improve the effects of document similarity measure and feedback of information retrieval systems. two approaches to evaluating the performance of this similarity measure and the comparison with standard cosine vector similarity measure are also described
介紹了一種綜合各層級分類類目和對應關鍵詞來構造概念體系並用於改進信息檢索系統效果的方法.為了改進文本聚類的效果，提出了將領域知識本體和文本關鍵詞詞頻相結合的基於餘弦向量的文本相似性測度方法.該本體面向特定領域，將關鍵詞以不同權值對應于各分類類目，通過其語義知識來改進文本相似性測度以及信息檢索系統的效果.進一步給出了對基於本體的相似性測度方法進行效果評價的2種策略以及該方法與經典餘弦向量測度方法的比較結果 -
On base of studying domestic and foreign theories and methods for evaluations of st achievements, this thesis analyze 10 methods for evaluations of st achievements, such as application frequency statistics, delphi, literature research and application relevance analysis, etc. by studying and analyzing the work of technology planning bureau, transport ministry between 1991 and 2000, and the evaluation items for the achievement identification, acceptance and check - up which were taken by transportation technology department, the author come up with some methods, which are scientific, standard and quantified, for evaluating transportation st, that is, in accordance with the transportation st achievement management and achievement precise database within eighth five and ninth five, and with the statistic analysis such as research contents, professional classification, intensity input, achievement characteristics, field distribution, characteristics of department undertaken, st talents characteristics, award inf ormation, characteristics and regularity of transportation st achievements, problems that are still existed and countermeasure are forwarded ; according to the requirement of evaluations system of the transportation st achievement, the principle and methods for the system designation are given, and the constitution of the system are provided ; in order to improving the scientific organization and management of our national transportation st achievements, many subjects are under discussion, including institution for evaluation of st achievement, valuation organization, standard for evaluation technology, database for consulting transportation experts and how to simplify the procedure of transportation st achievement, etc.
本論文在對國內外科技成果評價理論、方法廣泛調查基礎上，研究分析了諸如應用頻次統計法、德爾菲（ delphi ）法、文獻調研法、應用相關分析法等10種科技成果評價的方法，通過對1991至2000年交通部科技計劃所實施情況，由交通科技主管部門組織進行了成果鑒定、驗收和評審等成果評價的項目的分析，提出了本人對交通行業對科技成果進行科學、規范和定量地評價的方法，即：在建立「八五」 、 「九五」交通科技成果管理及成果簡要數據庫的基礎上，通過對研究內容、專業分類、投入強度、成果屬性、地域分佈、承擔單位屬性、科研人員屬性和獲獎情況等諸多方面進行統計分析，研究了交通科技成果的特點和規律，提出了存在的問題和對策；從建立交通科技成果評價指標體系的要求上，具體提出了交通科技成果評價指標體系設計原則與方法探討了交通行業科技成果評價指標體系的構成及權重確立等問題；從加強我國交通行業科技成果評價的科學化組織與管理出發，探討了如何建立科技成果評價制度、評價機構、統一的評價技術標準和交通行業專家咨詢數據庫以及如何簡化交通科技成果評審形式等問題。 -
Secondly, this thesis introduces the motor test methods according to nation motor test standard and ministry motor test standard, introduces the algorithm of automated test process, and analyzes frequency motor automated test to a certain extent. at the same time, this thesis introduces the design of the system software, and the way of dealing with, saving, output the measured data. at last, this thesis gives the way of improving the system, and with the combining with the foreign test system, discusses the trend of motor automated test system
本文首先將此電機自動測試系統和其他系統的硬體結構作了比較，分析了其優缺點；其次結合國家和部門標準，介紹了電機試驗的方法，自動測試的試驗過程演算法，並對變頻電機的自動測試作了一定的分析；再次介紹了系統軟體的設計和編寫，測試數據的處理、保存和輸出；最後對系統的進一步完善作了介紹，並結合國外的系統，對電機自動測試系統的發展方向作出展望。 -
The system can generate sweep frequency signal with frequency range from 100khz to 150mhz and power range from - 40dbm to + 18dbm, and measure the gain and phase of the crystal. according to the gain and phase information and the iec - 444 standard, crystal parameters can be calculated, such as nominal frequency, series resistance, shunt capacitance, motion capacitance, motion inductance, q factor and so on
該系統能產生頻率范圍達100khz 150mhz ，功率范圍為? 40dbm + 18dbm的掃頻信號，並能對晶振的增益和相位差進行測量，其測量結果按照iec - 444晶振測量標準進行實時處理和計算，從而得到晶振的串聯諧振頻率、並聯諧振頻率、等效電阻、靜態電容、動態電容、動態電感和品質因數等主要電參數。 -
Accuracy of the measurement system is verified by standard signal sources. frequency tracking error does not reach 50hz. the measurement system has merits of visual display and high accuracy, which is an ideal measurement system for dual - path saw mass sensor
應用標準信號源驗證了測量系統的精確性，頻率跟蹤特性誤差在50hz以內。該測量系統顯示直觀，精度高，是雙聲路聲表面波質量傳感器理想的測量系統。 -
In order to build and modify the national capacitance standard in the extended frequency range and testing system, national institute of metrology p. r. china establishes the corresponding project, named “ capacitance metrology ”, to study the technology of capacitance metrology in the extended frequency range
為了建立和完善國家現代電學計量標準中擴展頻段電容標準和檢測體系，中國計量科學研究院立項進行「電容擴頻」技術的研究。本文是筆者在參加該科研項目的基礎上完成的。 -
In such way, the frequency, the virtual value, the harmonic and power factor are acquired. it can achieve the intelligent control by way of cooperating with master station automatic apparatus system through adopting rs - 485 communication standard
同時根據采樣值系統計算了頻率、有效值、諧波、功率因數等電量，並通過rs - 485通信口與二級子站微機相配合，達到智能控制的作用。 -
Thanks to the support of the national natural science foundation of china under grand no. 50277036 for " the pulse electromagnetic fields and system - level em radiation of electric vehicles ", this thesis concentrated on the design of the variable voltage and variable frequency ( vvvf ) system and the development of a genetic algorithm for vector optimal design problems. the work includes mainly four parts : a brief introduction of the frequency - converter, the emc design of the vvvf system and the national standard of the electromagnetic interference of the vvvf system, the study of global search optimization algorithms, and an improved genetic algorithm called emigration genetic algorithm for multi - objective optimal problems
在國家自然科學基金資助項目《電動汽車脈沖電磁場與系統級輻射的研究》的工作基礎上，本文對電動車電磁輻射關鍵部分? ?變頻調速系統的電磁兼容性設計以及在電磁兼容性設計中涉及到的電磁系統的多目標優化方法進行了系統的分析和研究，其核心內容包括：變頻器工作原理；變頻調速系統電磁兼容性設計及變頻調速系統電磁兼容標準；隨機類全局優化演算法研究；提出了一種改進的遺傳演算法命名為遷徙遺傳演算法。 -
Though the flood control engineering system improved the flood control standard and reduce the frequency of flood inundation and enlarger the protected area, but at the same time, the risk of dike broken and dam failed were added. moreover, people found that human living environment become worsen increasingly and the river ecosystem was destroyed
然而，在與洪水斗爭的過程中，人們發現雖然通過大規模的水利工程建設，提高了江河的防洪標準，減少了洪水泛濫的幾率，擴大了防洪保護的范圍，但同時也增加堤防、大壩潰決等的風險，而且人類發現生存環境日益惡化，河流生態系統被破壞等諸多問題。 -
Software radio system is applicable to multiple frequency bands and it can change working mode flexibly. the system can interwork and is compatible with various equipment of different system and standard
軟體無線電系統適用於多個頻段，可靈活地改變工作模式，能與不同體制和標準的各種設備互通和兼容。 -
Electric performance index of the system is given. the ac standard equipment should be 3 - phase output standard resource by which the ac voltage, ac current, power factor, 3 - phase - 3 - line effective power, 3 - phase - 4 - line effective power, reactive power and single phase watt meter, working frequency and phase meter can be examined. the system makes full use of the main computer which has multi function in the examination
給出了電氣性能指標，交流標準裝置應為三相輸出標準源、使其可校驗交流電壓、交流電流、功率因數、三相三線有功功率、三相四線有功功率、無功及單相電能表，同時可校驗工頻頻率表及相位表，在校驗檢測中充分發揮主機多能的作用。 -
In this dissertation, the present research status of standard vibration metrology technique at home and abroad is introduced, and the significance of developing ultra - low - frequency standard vibration metrology is discussed as well. systematic research has been done in developing ultra - low - frequency standard vibrator. several key technical problems are solved in order to develop the calibration system of this kind of vibrator
本文在分析了國內外標準振動計量技術的研究現狀以及超低頻標準振動計量的重要性的基礎上，以研製超低頻標準振動臺校準系統為目的，對建立超低頻標準振動臺校準系統的若干關鍵技術及其實現方法進行了研究。 -
Firstly, the properties of vibration transducers and their calibration methods are given, and the significance of establishing ultra - low - frequency standard vibration calibration system is pointed out. secondly, the present research status on standard vibration metrology at home and abroad is surveyed. thirdly, some problems in the ultra - low - frequency standard vibration metrology and the future direction are pointed out
首先介紹了振動傳感器的特點及其校準方法，指出建立超低頻標準振動計量的重要性；然後回顧了國內外標準振動計量的研究現狀；接著分析了超低頻標準振動計量存在的問題並指出了研究方向；最後介紹本論文的研究內容。
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