最低可用頻率 的英文怎麼說
中文拼音 [zuìdīkěyòngbīnlǜ]
最低可用頻率
英文
lowest useful frequency-
The specific research methods are listed : 1. matched filter taking the max ouput snr as the best rule correlates nonstop divided signal and divided echo to detect low snr target signal. then all one dimension divided correlation outs and done fft in portrait to leach interferential signal such as static or low rate mussy meaves, many pathway echo and so on and to take target ' s time difference and doppler frequency that combine parameters that target ' s direction taken from antenna and so on to implement target ' s orientation and tracking
具體研究方法如下： 1 、採用以輸出信噪比最大為準則的最佳匹配濾波器來對分段的參考和目標信號作相關處理來檢測低信噪比目標信號，然後對一維分段相關輸出組作縱向傅立葉變換來濾除靜態或低速的雜波、多徑回波等干擾信號，並提取目標的時差和多普勒頻率，再結合由天線獲得的目標方向等參數，就可以實現目標的定位和跟蹤。Choose two nodes on the edge of the structural to compare the results calculating by the finite element program midas, then we can draw a conclusion that these kinds of space truss systems is sensitive to the libration of the dynamic wind loads. to consider this factor is very necessary in the process of design, we will use the pulsant augmentation coefficient to realize it
比較靜力風荷載和動力風荷載作用下的有限元軟體的計算結果，選取結構邊緣部分的兩個節點，對比它們在兩種方法計算下的最大位移的計算結果。經過比較可以看出重量輕、頻率低、阻尼小的柔性建築物對風荷載的橫向振動是很敏感的，在進行工程設計時應該考慮這種因素，並可採用乘以風振系數等相應方法來加以體現。The raw materials, the composition, the time of milling, the calcining temperature, the different additives, the sintering temperature and the sintering parameters were investigated. the result showed : it was advantaged to obtain high initial permeability mnzn ferrite with stable frequency characteristic using high - purity raw materials ; in order to obtain mnzn ferrite with high properties, we must control strictly the composition ; it could improve the properties of mnzn ferrite by optimizing calcining temperature. the lower calcining temperature made the permeability higher, and the higher calcining temperature could promote the frequency characteristic of permeability ; we chosen the right time of milling according to the requirement of power diameter ; in order to improve the properties of mnzn ferrite, it is necessary to add effective additives. in this dissertation, the influence of bi2o3 、 moo3 、 k2co3 、 co2o3 were investigated ; the sintering temperature, the time of heat - retaining and sintering parameters were the key factors of preparing high permeability mnzn ferrites
研究結果表明:採用高純度的fe2o3有利於獲得高起始磁導率且頻率特性優良的鐵氧體;為了制備所需性能的鐵氧體，需要嚴格控制配方中各種原材料的含量，優化配方;由於粉體活性受預燒條件的影響，所以對不同要求的鐵氧體選擇的預燒條件就不一樣，適當降低預燒溫度有利於獲得較高的起始磁導率，而為了獲得良好的頻率特性可以適當地提高預燒溫度;根據對粉體顆粒粒徑的不同需求，可以選擇不同的球磨時間;而有效的添加劑是改善材料性能的必要條件，本文在添加劑的研究中主要對bi2o3 、 moo3 、 k2co3 、 co2o3的影響分別作了詳細地討論;燒結溫度、保溫時間和燒結氣氛是高磁導率mnzn鐵氧體制備最關鍵的工藝，適宜的燒結工藝可以獲得理想微結構和組成，從而得到高性能的鐵氧體材料;而從材料的微結構上來看，要提高材料的截止頻率，就要適當地細化晶粒、增加晶粒內部的氣孔。Due to the short distance among the planes which fly in a group, the conventional low resolution radar can not distinguish them in both distance and azimuth ? if we use the technology of isar to resolve the difference among doppler frequency of the targets and obtain a fine resolution cross - cross image, we may separate them, but a long time of coherent processing is needed <, for the formation targets, it can be approximately divided to rigid body and nonrigid body, so for the formation targets, that can be regarded as rigid which has a relative position and an identical movement, can be approximately considered as a large target, and be compensated by translational phase with the rule of minimum entropy, but for the most those cannot accord with the approximation of rigid, being the doppler - frequency of the aim is linear changed, by the relax method with short data, increases the resolving performance of multiple target to the aim in the frequency domain, since cross - range resolution is based on the accumulative time, so it is greatly improve the resolution to formation targets by the instant cross - range image which produced by radon - wigner transformation
低分辨isan成像及干涉技術應用研究一因此直接無法分辨編隊目標的架數，我們借鑒isar的技術，通過較長時間的相干積累，在多普勒頻域上對目標進行分辨。而對于編隊目標，可分為近似剛性的多目標和非剛性的多目標，所以對于可以近似為剛體的編隊目標相對位置固定，運動方式一致，可以近似看作一個大目標，採用最小墑準則對平動相位的進行補償，但是大多數並不滿足剛體近似的編隊目標，由於目標在相干積累時間的多普勒頻率近似呈線性變化，通過對較短數據利用relax的時頻分析方法，提高了頻率域上目標分辨的性能。由於橫向解析度取塊于橫向積累時間，所以利用radnwigner變換得到瞬時的一維橫向距離像大大提高了對編隊目標的分辨，對模擬和實測數據的大量分析結果表明此方法的有效性和可行。The essence of edid is to set up a normal behavior fuzzy sub collection a on the basis of watching the normal system transfer of the privilege process, and set up a fuzzy sub collection b with real time transfer array, then detect with the principle of minimum distance in fuzzy discern method the innovation point of this paper is : put forward the method of edid, can not only reduce efficiently false positive rate and false negative rate, also make real time intrusion detection to become possibility ; have independent and complete character database, according to the classification of monitoring program, design normal behavior and anomaly behavior etc., have raised the strongness of ids ; use tree type structure to preservation the character database, have saved greatly stock space ; in detection invade, carry out frequency prior principle, prior analysis and handling the behavior feature of high frequency in information table, have raised efficiency and the speed of detection, make real time intrusion detection to become possibility ; have at the same time realized anomaly intrusion detection and misuse intrusion detection, have remedied deficiency of unitary detection method
這種方法的實質是在監控特權進程的正常系統調用基礎上建立正常行為模糊子集a ，用檢測到的實時調用序列建立模糊子集b ，然後用模糊識別方法中的最小距離原則進行檢測。本文的創新點是：通過對特權進程的系統調用及參數序列的研究，提出了基於euclidean距離的入侵檢測方法edid ，不僅能有效降低漏報率和誤報率，而且使實時入侵檢測成為可能；設計有獨立而完整的特徵數據庫，根據被監控程序的類別，分別設計正常行為、異常行為等，提高了檢測系統的強健性和可伸縮性；特徵數據庫按樹型結構存儲，大大節省了存儲空間；在檢測入侵時，實行頻度優先原則，優先分析和處理信息表中的高頻度行為特徵，提高檢測的速度和效率，使實時入侵檢測成為可能；同時實現了異常入侵檢測和誤用入侵檢測，彌補了單一檢測方法的不足。The conclusions obtained as follows : firstly, the structure ' s free frequency is decreased by the reduction of the mechanical property of the material with the increasing temperature ; secondly the thermal stress produced by the temperature gradient may decrease or enlarge the structures natural frequency ; thirdly, the variety of natural frequency of the alloy structures effected by the heat effect apparently higher than that of the composite material structures
最後，採用ansys程序分析了合金材料、復合材料的板、彈體結構的熱振動特性。在不同的熱載條件下，取得以下結論：升溫導致的材料機械性能下降都會降低結構固有頻率，而溫度梯度產生的熱應力可能降低也可能提高結構的固有頻率；金屬材料結構的固有頻率受溫度的影響要比復合材料結構的固有頻率受溫度的影響要明顯。When the frequency approaches zero, the factor approaches zero correspondingly ; 2 ) the amplitude of interaction factors changes with the incident angle of rayleigh waves and reaches maximum when is zero. moreover, with the increase of, the wave period shortens apparently ; ( 3 ) the amplitude of interaction factors decreases as the pile spacing increases and approaches to zero when the pile spacing is 15 ; 4 ) the amplitudes of interaction factors increase clearly with the increasing stiffness ratio of pile to soil ; 5 ) the lat eral seismic response of fixed - head pile groups is much smaller than that of free - head pile groups. moreover, the pile - group effects induced by rayleigh waves can be neglected ; 6 ) the lateral seismic response of piles at different location differs from each other
得到了以下結論： 1 ）樁的相互作用因子隨頻率呈周期性變化，在振動頻率比較低的情況下，樁的橫向相互作用因子也較低，當頻率趨近於零時，相互作用因子也趨近於零； 2 ）樁的相互作用因子的幅值隨瑞利波入射角度的變化而變化，在= 0情況下幅值最大，且隨入射角度的增加，波動的周期明顯縮短； 3 ）樁的相互作用因子的幅值隨著樁與樁間距的增加而減小，至s d = 15時，樁的相互作用因子基本趨近於0 ； 4 ）在頻率比較低時，相互作用因子幅值隨樁土相對剛度比的增加而顯著增加； 5 ）樁頂固接可以有效地降低群樁的橫向地震響應幅值，由瑞利波產生的群樁效應可以忽略不計； 6 ）群樁中不同樁位的樁的橫向地震響應是不同的，每根樁所在的樁位對其橫向地震響應有很大的影響；刀樁數的增加並不能減小樁的橫向動力響應。22 paired inferior collicular neurons were obtained in the experiment. the neurons were recorded in the depth of 198 - 1254 u m ( 544. 59 ? 72. 37 n m, m + sd ), and their bfs were 11. 25 - 59. 29 khz ( 26. 77 + 9. 95 khz, m ? d ) : the minimum thresholds ( mts ) werelo - 66 db spl ( 38. 14 ? 14. 39 khz, m + sd ) ; the latencies were 4. 0 - 16. 0 ms ( 8. 19 + 3. 14 ms, m + sd ) ; the best intervals between paired sound pulses were 0. 01 - 28. 71 ms ( 3. 93 + 2. 52 ms, m ? d ) 0 the results showed : l ) there were interactions between the neurons in the iso - frequency lamina and hetero - frequency lamina which included mutual inhibition ( 18 / 22, 81. 8 % ) and mutual facilitation ( 4 / 22, 18. 2 % ), and the mutual inhibition in iso - frequency lamina was stronger than that in hetero - frequency lamina ; 2 ) the mutual inhibition decreased with sound level increasing ( p < 0. 001, anova ) ; 3 ) the analysis of the inhibition of discharge rate at lodb above mt showed that the inhibition increased when the paired neurons " bfs difference decreased ( r = - 0. 545, p = 0. 0006 ) ; 4 ) the mutual inhibition of paired neurons can sharpen the frequency tuning and the effect increased when the frequency was away from the bf ; 5 ) the changes in q10, q30 decreased with bfs difference of the paired neurons increasing ; 6 ) the mutual facilitation between paired neurons not only increased discharge rate, but also widened the frequency tuning, i. e., increased response frequency
結果表明： 1 ）同頻層神經元之間或者非同頻層之間神經元之間存在相互作用，這種作用既有相互抑制（ 18對，佔81 . 8 ） ，也有相互易化（ 4對，佔18 . 2 ） ，且同頻層神經元之間的相互抑制作用較非同頻層神經元之間的相互抑制作用要強； 2 ）神經元對低刺激強度反應時，所受到的相互抑制作用較強，隨著聲刺激強度加大，抑制作用逐步降低（ p 0 . 001 ， anova ） ； 3 ）對閾上10db放電率抑制百分比進行的分析顯示，配對神經元之間的最佳頻率差越小，相互抑制作用越強（ r = - 0 . 545 ， p = 0 . 0006 ） ； 4 ）配對神經元之間通過相互抑制作用可表kx碩士學位論文waiaster 』 sthesis現出調諧銳化作用，該作用的效率與頻率有關， bf處的銳化作用較低，偏離bf時其銳化作用逐步加強； 5 ）頻率銳化作用的效率與bf差有關，隨著配對神經元之間的bf差擴亢q10 ， q30值的變化逐漸減小，其變化百分比與配對神經元之間的頻率差存在明顯相關； 6 ）配對神經元之間的相互易化作用不僅表現在放電率增加上，也表現在頻率調諧曲線的擴寬，即頻率響應范圍擴大。The results show that wavelength locates in gain zone of semiconductor optical amplifier, and have higher peak power and proper time delay between the two pulses for the second order super gauss control pulse in semiconductor optical amplifier. a high quality amplified signal pulse can be achieved. the chirp can be reduced notability by using cascading soa in cross gain modulation based on soa, and the distance and the peak power of conversion optical pulse can be increased notability, and we can let down the demand for wavelength based on xgm in soa and enhance the flexibility of wavelength conversion
我們應用二階超高斯光脈沖與高斯信號脈沖同時注入soa和應用soa與非線性光學環鏡（ nolm ）相結合的方案來對信號脈沖進行壓縮整形，模擬顯示，在調節系統合適參數的情況下，波長位於soa增益區的二階超高斯控制光脈沖在具有較高的峰值功率和適當時延下輸入soa時，最後可以得到放大的高質量超簡訊號光脈沖；在基於soa的交叉增益調制（ xgm ）全光波長轉換中，採用級聯的soa能有效地使反轉光脈沖的頻率啁啾得到有效降低，波長向下轉換的距離和反轉光的峰值能量都得到明顯提高，降低了利用交叉增益調制（ xgm ）波長轉換中對波長精度的要求，從而提高了波長轉換的靈和性。It adapts to the cdma system and achieves multi - rate speech coding and decoding. source and mode control are combines in smv for rate selection, so it improves the flexibility of cdma system, it will allow cdma subscribers to enjoy superior quality while allowing service providers to increase capacity as needed. smv is regarded as a breakthrough technology that provides significant capacity and quality gains on cdma systems, so the researching of smv is of great practical value
可選模式聲碼器（ smv ? selectablemodevocoder ）是3gpp2最新的用於寬帶擴頻cdma通信系統的變速率語音編碼標準，它實現了語音的多種低速編碼和解碼，在速率選擇上將源控和模式控制相結合，提高了cdma系統的靈活性，可以在保證高質量語音的同時盡可能增加系統的容量，被認為是變速率語音編碼在cdma系統中應用的「突破性」技術，代表了當前語音編碼發展的方向和潮流，因此smv的研究具有很大的價值。Multi - uesr detection ( mud ) refers to signal detection in multiple access communications. this detection has many good properties, such as decreasing multiple access interference, canceling out or moderating near - far resistance, able to decrease the requirement for output control, compensating the effects due to inoptimal orthogonality, improving system performance and increasing system capacity. mud is one of the methods that can overcome the mai in cdma with most potential and complete and becomes one of the critical techniques in the third generation mobile communication
多用戶檢測是指多址通信中的信號檢測，具有抑止多址干擾;消除或減輕遠近效應;可適當降低對功率控制的要求;彌補擴頻碼互相關性不理想造成的影響;改善系統性能，提高系統容量等眾多優點，是克服cdma多址干擾最有潛力、最徹底的一種方法，並已成為第三代移動通信標準中倡導的關鍵技術之一。The error of distortion which harmonic distortion meter detects can be least controlled 1. the lowest frequency which harmonic distortion meter can detect is 0. 0001hz. but, generally, this kind of meter is so costly and difficult to operate that the major portion of the distortion meters applies the method of suppressed fundamental harmonic
採用諧波分析法的失真度儀測得的失真度的最小誤差可控制在千分之一以下，頻率最低可達到萬分之一赫茲，但普遍存在儀器價格較貴，操作繁瑣的缺點，現在用的失真度測試儀大多是用基波抑製法。Lowest usable frequency
最低可用頻率Owing to the use of ac square wave with little amplitude value, the effect of polarization is depressed. the frequency can be adjusted continuously, so. the effect of the double electricity capacitance is depressed too. and the measurement is not affected by the amplitude values of the ac square waves using rule of three in computation, so the precision is promoted
由於使用交流方波，且幅值很小，將極化效應影響降至最低。又由於頻率連續可調，雙電層電容的容抗可降至最小。在求解過程中，測出交流方波幅值和直流量進行比例運算，消除了交流方波幅值對測量的影響，進一步提高了測量精度。分享友人