near by frequency 中文意思是什麼
near by frequency
解釋
鄰近頻率-
During the near three decades, high - frequency ground wave radar detecting for sea has been regarded for its high performance by many countries
近三十年來，高頻地波對海探測雷達因其本身所特有的優點而引起了許多國家的高度重視。 -
In the thesis, a signal processing scheme of polarization - insensitive fiber optic michelson interferometric magnetic sensor is described : making the interferometer work near the quadrature with closed loop controlling working point method, the fundamental frequency component of the magnetic field sensing signals can be detected to measure the input direct current ( dc ) magnetic field by phase sensitive demodulation
本文主要介紹了偏振無關光纖michelson干涉型微弱磁場傳感器信號處理的方案:通過閉環控制工作點演算法使干涉儀工作在正交工作點處，再利用相敏檢波演算法提取傳感器輸出信號的基頻分量，以測量直流磁場的大小。 -
Some people living near wind farms complain they are kept awake by a phenomenon known as aerodynamic modulation ( am ), low frequency noise made as the blades swoosh through the night air
有些住在風力發電廠附近的人抱怨，他們因為一種稱為空氣動力調變的現象，即輪葉的颼颼聲劃過夜空，產生低頻噪音，以致無法入眠。 -
This paper mainly discusses the vital part discrimination of the near - field target by using target acoustic imaging method, which uses dense narrow beams based on high frequency system
本論文主要研究了基於高頻體制下利用密集窄波束形成目標圖像，進行近場目標精確識別。 -
The conformal microstrip antenna with some unique character has been applied in many fields, especialy on speedy objects. in this paper, an efficient fdtd algorithm is introduced to analyse the microstrip antenna. firstly, the fdtd formula in descartes coordinate system and in cylindrical coordinate system are obtained from the time _ dependent maxwell equations using the yee algorithm in a calculating region where the dielectric parameters are independent of time and space. the choice of the space discretization units and the time discretization interval are discussed which are decided by the accuracy and stability respectively. the shape and setup of the excitation source are discussed too. the excitation source is chosen to be gaussian pulse in shape. secondly, the mur ' s first - order and second - order boundary condition are deduced in cylindrical coordinate system. the methods of transforming radiation fields from near zone to far zone in the frequency domain and in the time domain are presented when fdtd is applied to analyse the characteristics of far zone. finally, three kinds of microstrip antennas are analysed. they are a slot antenna that lies on a plane ground of a microstrip, a slot antenna that lies on a cylindrical ground of a microstrip and a microstrip line _ fed aperture coupled stacked rectangular patch antenna in cylindrical coordinate system
本文從麥克斯韋旋度方程出發，建立了笛卡兒坐標下無源空間中均勻無耗媒質的fdtd基本方程和圓柱坐標下無源空間中均勻無耗媒質的fdtd基本方程，詳細討論了fdtd法計算中時間步長和空間步長的選取原則以及激勵源的類型和設置；推導了mur一階和二階邊界條件在圓柱坐標下的差分格式；給出了在用fdtd法計算天線的遠場輻射特性時必需採用的頻域和時域近場遠場變換技術；最後用fdtd法計算了平面微帶縫隙天線、柱面共形微帶縫隙天線和柱面共形微帶層疊天線的輸入阻抗和遠區輻射場，並分析了天線的一些參數的變化對天線輸入阻抗的影響，得出了一些有用的結論。 -
On the other hand, inhibitory areas of ftc could be abolished partially or completely during bicuculline application. these results showed that gabaergic inhibitory afferent projections to recorded neurons were activated by random resonance caused by weak noise in cochlea, which provided inhibitory input for sharpening frequency tuning and made neuron more precisely analyze sound signal near its bf. therefore, this experiment presented a possible evidence of cellular level for interpreting why human and animal could extract or capture sound signal of specific frequency from the environment with competing noise
說明山弱噪聲引起的耳蝸隨機共振在_ _仁行傳入過程中可能激活了至所一記錄的jc神經元的gaba能抑制性神經迴路，這種gaba能抑制為銳化神經元頻率調諧提供了一種抑制性輸入，使ic神經元對靠近最佳頻率的頻率分析變得更為細致和精確，由於聲頻率是聲信號的重要參數和信息載體，頻率調諧的銳化意味著對聲頻率分析能力增強，從而為解釋人們為什麼能從充滿噪聲的環境中捕捉或提取與行為學相關的信號提供了一種細胞水平的實驗證據。 -
This structure possesses common spectra gaps with transverse - electric surface waves and transverse - magnetic surface waves, a multiple of in phase frequency regimes to characterize magnetic resonances are also within those spectra gaps, which were detected both by measuring return loss of an antenna near the surface and by fdtd simulations
實驗和數值模擬顯示這類表面的橫電模式極化和橫磁模式極化的表面波具有多帶隙的豐富能帶結構，同時它還有多個磁性諧振頻率，實驗和理論顯示這些磁性諧振所對應的多個同位相反射區落在兩個表面波帶隙中。 -
Since the cause of caustics phenomena is that the tangent plane of lagrange submanifold in caustic fields is perpendicular to the original physical space, we solve the high frequency asymptotic problem in a new mixed space by changing the projecting direction, then we get the high frequency asymptotic solutions of wave equations efficiently near and on the caustics
由於出現焦散現象的原因在於lagrange子流形在該處的切平面與物理空間垂直，通過轉換適當的投影方向，然後將這個投影方向上得到的高頻近似解再變換回到原來的物理空間中，得到了在焦散附近適用的高頻近似解。 -
The key points of this paper can be concluding as follows : 1. the regulations of vibration attenuation of a subway are concluded by analyzing the situ data. in the zone near rail, the high - frequency vibration is stronger than other weight, and in the zone far away from railway, the results is opposite
主要研究內容和結果如下: 1 .對某地鐵線路環境振動實測數據進行了分析，得到了振動波在土中的傳播規律:地鐵運營誘發振動傳播過程中，近軌區域以高頻振動為主，遠軌區域以低頻振動為主。 -
By the usage discovers the existing synchronous controller while near to resonance area and the low frequency areas of vibrate the pedestals, drive the signal and the feedback signalses all very small, control result is not very ideal
經過使用發現現有同步控制器在接近振動臺的共振區和低頻區時，驅動信號和反饋信號都很小，對幅值和相位的控制效果不能滿足要求。 -
Based on fourth - order cumulant, a computationally efficient method for joint estimating both directions of arrival and ranges of near field sources with known carrier frequency is firstly presented. the proposed algorithm need not any spectral peak searching and the 2 - d parameters are automatically paired. lt is suitable for arbitrary additive gaussian noise environment. in the following section, a 3 - d esprit method for jointly estimating of frequencies, doa ' s and ranges of multiple near - field sources with unknown carrier frequencies is proposed. the parameters estimation are given by the eigenvalues of different matrices. furthermore, its performances are confirmed by several computer simulations
利用四階累積量，第五章首先給出了一種載頻已知的情況下基於近場源的距離和波達方向聯合估計演算法，通過構造的陣列輸出信號四階累量矩陣使空間信號到達方向和距離估計無需譜峰搜索，且參數自動配對，適合於任意高斯噪聲環境。進一步在第三節提出了一種載頻未知的情況下的多個近場窄帶信號源doa 、距離和頻率聯合估計的3 - desprit演算法。 -
Any mechanical system can vibrate under certain conditions. if the frequency of exciting force caused by external drive or self - unbalance is near the nature frequency of the system, a phenomenon named resonance vibration will occur
任何機械繫統都會發生振動，當外界激勵或自身不平衡引起的激振力的頻率與系統的固有頻率接近時，就會發生共振。 -
The main numerical method of this code is coming from scheme ( jameson, schimit and turkel ) : using cell - centered finite volume method as spatial discretization tools, and a system of ordinary differential equations for time variable is obtained, which is solved by utilizing five - step runge - kutta scheme as time marching method, introducing artificial dissipation to damp high frequency oscillations near the shock and stagnation point
本論文採用歐拉方程作為控制方程，利用中心有限體積法進行空間離散，得到對時間變量的常微分方程組，採用龍格庫塔多步法進行時間積分，加入人工粘性以消除激波和駐點附近的壓力振蕩等方法來對naca0012翼型的實際流動進行并行數值模擬。 -
If the field frequency is low, the acoustic solution of rotating sources in near field can be expressed by the far field acoustic solution plus some near field modifications
摘要旋轉運動源近場聲學頻域解可以表示為在遠場解基礎上疊加近場修正項。 -
The problem of signal processing for direct - sequence code - division - multiple - access ( ds - cdma ) signal over multipath frequency - selective mobile channels is considered. a new blind receiver is proposed. without the knowledge of the multiple - access interference users spreading code and the channel characteristics, the receiver achieves blind detection with prior knowledge of only the desired users spreading code and approximate timing. by using reduced rank adaptive decorrelating filter and adaptive multipath combiner which is based on decision - directed algorithm, the receiver gets the ability to combat both fading and the near - far effect at low cost. simulation results demonstrate that the proposed receiver offers high performance
本文研究多徑頻率選擇性衰落通道下直接序列擴頻碼分多址（ ds - cdma ）信號的處理問題，提出了一種新型的盲接收機.該接收機不需預知多址干擾用戶的擴頻碼，不需預知通道參數，只需已知期望用戶的擴頻碼和粗略的定時，就可以完成用戶的盲檢測.同時，該接收機通過降維自適應去相關濾波和基於判決指導的自適應多徑合併，來獲得低成本和良好的抗衰落、抗遠近效應性能.模擬結果驗證了本文提出的接收機的優良性能
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