頻率機敏 的英文怎麼說
中文拼音 [bīnlǜjīmǐn]
頻率機敏
英文
frequency agility-
Intermodulation suppression for fh ( frequency hopping ) receiver is designed by selecting the intermediate frequencies and changing group of filters, local oscillation ( lo ) frequency, bandwidth of lo frequency under the condition that receiver configuration, sensitivity, dynamic range, instantaneous bandwidth and precision of frequency measurement are fixed
摘要針對跳頻接收機的體制和靈敏度、動態范圍、瞬時工作帶寬、測頻精度等設計參數，通過改變預選器組成、本振頻率和本振帶寬，分析接收通道的中頻選取原則，以實現跳頻接收機的互調抑制設計。This design keep the twice frequency transform and the superheterodyne structure in analog receiver, and use programmable direct digital synthesizer ( dos ) in rf section. use this method, we can not only inherit the advantage of high sensitivity and high selection in traditional design, but also improve the automation of the equipment
該方案保留了原模擬接收機二次變頻的超外差結構，在射頻前端利用了可編程的數字頻率合成器（ dds ） ，這樣既繼承了原接收機的高靈敏度，高選擇性的優點，又提高了它的接收機自動化特性。The results showed that the intensity of uterine contraction was reinforced by mifepristone and misoprostol used in combination ; and the random uterine contraction was effectively inhibited and the effective uterine contraction was strengthened by acupuncture
為探討針刺、藥物抗早孕的作用機制，我們採用早孕大鼠模型，建立間接反映子宮內壓的記錄方法，安放電極記錄子宮收縮頻率、強度作為判斷宮縮變化的指標，科學、簡便、靈敏、客觀地記錄宮內壓變化及子宮收縮情況。This article according to the acquirement of the system parameters such as : temperature sensitivity 、 angle resolution 、 image forming time etc to design the type and diameter of the antenna ; the receiver type, integral time, rf gain, lpf gain ; the mode of calibration ; the sample frequency and program of the daq ; the scanning time, scan type, etc
本文根據系統溫度靈敏度、角解析度、成像時間等參數要求，對系統天線類型、直徑，接收機類型、積分時間、射頻增益、視頻放大器增益，定標方式，數據採集卡的采樣頻率、編程及驅動裝置的掃描速度、掃描類型等進行了詳細的分析設計。By choosing flood control system of downstream basin of the yellow river as the background, six relatively independent subsystem is established, which includes basic information management, real - time flood forecast, multi - reservoir flood control scheduling, consultation and analysis, scheduling scheme management, frequency analysis, and assist with friendly man - machine conversation to constitutes the yellow river downstream flood control scheduling decision support system, which can satisfy the practicability requirements of decision - making
論文以黃河下游防洪系統為背景，建立包括基本信息管理、短期洪水預報、水庫（群）防洪調度、會商與靈敏度分析、方案管理、水雨情頻率分析等6個相對獨立的子系統，並輔以友好的人機交互界面集成為黃河下游防洪調度決策支持系統，滿足了群決策會商的實用性要求。The flat yarn making machine is adopted micro - processor control, frequency conversion governor and setting and displaying technical data may be fully digitized on the basis of absorbing international advanced techniques. the main parts use quality products. the line enlarges l d ratio and adopts new type of separating screw and widens mixing smelt zone on the extruder screw pot which is specially processed using quality steel, fine plasticized effect, low energy consumption in relation to output
本平膜拉絲機組是我廠在廣泛吸收國外先進拉絲機組技術基礎上，採用微機控制變頻調速及可控硅直流調速等先進技術研製而成的，主要電氣元器件採用國外優質產品，整機結構設計先進控制靈敏運行平穩操作方便安全可靠生產效率高能量消耗低。The receiver works on active mode and passive mode in different time. in active mode, the receiver is narrow - band and high sensitive, and if phase - lock technology is used to stabilize receiving frequency. and in passive mode, the receiver is an all - power millimeter wave radiometer with periodic calibration to improve measure precision
此接收機採用分時工作體制，在主動工作方式時為窄帶的高靈敏度毫米波接收機，接收機中採用中頻鎖相技術，簡化了毫米波鎖相帶來的困難；在被動工作方式時為全功率型的毫米波輻射計，這種輻射計在每次測量后都採用兩個標準源對輻射計定標，實現周期定標，消除因系統增益波動和有效本機噪聲波動帶來的測量誤差，提高測量測量精度。In large rotating machinery using filmatic bearing ( turbogenerator, air compressor, etc. ) there is a potential trouble from impefect installation or running conditions, a metals " contact between rotors and shells. the trouble is usully called rubbing. the advantage of ae technologe in the rubbing diagnosis and early detection is showed. instead of classical ae characteristic parameters ( counts, amplitude, energy, duration and the other ones ) a new feature extraction by frequency analysis of ae envelop signals is discussed. both research of ae process and field experements indicate that periodic components in the envelop spectrum related to rotational speed increase evidently at the beginning of rubbing production, hence are highly sensitive to the rubbing fault diagnosis. according to the new design an acoustic emission equipment for the rubbing diagnosis named buaa ae testing system is developed and described
汽輪發電機、空氣壓縮機等採用油膜支撐的大型轉動機械，由於安裝或運行中的原因，在轉子旋轉過程中，可能和器壁發生輕微的摩擦和碰擊，簡稱碰摩.聲發射技術在碰摩發生特別是故障早期診斷上有優越性.本系統的特點是沒有沿用傳統的計數、幅度、能量和持續時間等聲發射特性參數，而是在聲發射包絡信號的頻率分析中進行特徵提取.聲發射發生的過程分析和現場試驗都表明這種方法對碰摩檢測很敏感，在碰摩發生的起始階段，包絡譜中與轉速同步的周期性分量顯著增加.根據這種新的設計思想自行研製了buaa碰摩聲發射檢測儀並對此作了介紹In addition, a sophisticated mechanism derived from dwt coding is introduced to take into account several hvs phenomena such as gray - level sensitivity, noise sensibility around edges and isofrequency and nonisofrequency masking
另外，引入了一個由dwt編碼而來的復雜的機理來考慮幾個hvs現象如灰度級敏感度、邊緣噪音敏感度和頻率掩蔽。That extremely promotes the development of the receiver. also the requirement of receiver becomes more rigorous. as the name implies, receiver need to improve the linearity, to reduce the distortions rate and bit error rate, and to expend the dynamic range, of course should ensure the signal detect capability precondition
這些要求同樣也促進了中頻接收機的不斷進步，要求其在保證信號檢測能力（即極高的靈敏度）的前提下:盡可能的提高接收機的線性度，使信號失真最小、誤碼率最低;盡可能的展寬接收機的動態范圍，使接收機的適應度更大、抗干擾能力更強。Experiments on board shows that strain method to measure the shaft power has many advances, e. g., high sensitivity, wide measuring span, rapidly frequency - response, light hysteresis, small size and weight - light of the equipment, remote - controllable
應變電測技術在艦船軸系軸功率測試中得到廣泛的應用，是由於該系統具有靈敏度高，測量范圍廣；頻率響應快，機械滯后小；體積小、重量輕；可實現遙控等諸多優點。In this paper they study a position - detecting system based on microprocessor and psd ( position sensitive detector ). the method is as follows : when the ac - signal from psd which is illuminated by modulated light source passes through an active band - pass analog filter, it filters the ac signal which represents the object light source. then the dc - converter circuit transforms it into dc - signal which is used to calculate the position
這一系統採用的方法是通過對位置敏感探測器psd受到調制目標光源照射后輸出的模擬交流信號進行有源帶通濾波，提取出代表目標光源的調制頻率成份，再將該信號轉變為用來參與位置解算的直流信號，然後選用單片機組成硬體電路，對直流信號進行採集處理並與計算機建立通信，把數據送入計算機進行位置解算，分析判別目標光源和psd器件的相對位置。Firstly, in wireless environment, receiver has no know the time delay between transmitter and itself. in ofdm system, ofdm data is transmitted as one symbol, so in order for correct demodulation, the correct start of symbol should be got from ofdm system to reduce the effect of isi. secondly, the high frequency utilization in ofdm is based on the orthogonal properties of sub carriers. if frequency offset is generated, the orthogonal properties among sub carriers will lost, that will cause inter carrier interference ( ici ) and high ber of system
Ofdm技術也存在著一些缺陷，首先，在無線環境中傳輸的ofdm信號對定時要求高，為了減少碼間串擾（ isi ）影響，必須從接收信號中提取出正確的符號起始位;其次， ofdm系統對頻率偏移敏感， ofdm技術的高頻譜利用率和傳輸可靠性均以子載波的正交性為基礎，如果接收機和發射機之間發生頻率偏移，子載波之間就會失去正交性，導致嚴重的子載波間干擾（ ici ） ，降低系統性能。分享友人