頻段開關 的英文怎麼說
中文拼音 [bīnduànkāiguān]
頻段開關
英文
band sw-
After analyzing the switching characteristic of mosfet, the object function of optimizing curve of the output capacitance coss is confirmed according to the switching loss caused by output capacitance coss, then the optimized curve of the output capacitance coss is ascertained by applying zoutendijk to seek the optimized value with constraint ; the simulation of switching circuitry and dc - dc circuitry is tested at different frequency in pspice, then the least square method is adopted to fit simulation curves to calculate corresponding energy data
在電子線路模擬軟體pspice中進行了mosfet開關電路以及典型dc dc轉換線路模擬測試，針對不同頻段的測試結果，採用最小二乘擬合法對模擬曲線進行擬合，計算出相應的能量數據，最後綜合模擬結果確定出減小器件開關損耗，提高dc0c轉換線路效率的器件輸出電容cob優化曲線。The purpose of this web site is to share my experiences with workers in any country on water logging in agricultural lands, irrigation induced soil salinity, subsurface drainage for agriculture ( horizontal and vertical ), reuse of groundwater, ground - water hydraulics, ( geo ) hydrology, rainfall and surface runoff relations, reclamation and improvement of water logged saline, salty, sodic alkaline, and acid sulphate soils, plant growth, crop production and responses as well as statistical analysis consisting of segmented linear regression and cumulative frequency distributions
描述:探討農業耕地的水澇問題；灌溉導致的土壤鹽堿化；地表灌溉；地下水的再利用；地下水水力學；雨水與水流失的關系；淺地表排水；土壤開墾及水澇，酸性，堿性土壤的改良；片段線形回歸和累積頻數分佈的統計分析等。With the mathematic model of tracking beam current by velocity, real - time tracking can be obtained ; with current simulation controlling transducer and subsection linearity, precision of velocity ( error in ? 1 % ) is triumphantly can be controlled ; with inspection of the pulse numbers of switches, the position of all vehicles are checked to eliminate the error of calculating distance between all ones
通過建立速度跟蹤束流的數學模型，較好地解決了速度跟蹤束流的實時性問題;通過採取用電流模擬量控制變頻器和分段線性處理的辦法，成功地解決了速度精度問題（誤差在士1 %內） ;通過檢測接近開關觸發的脈沖數，適時校核所有小車位置，消除各車之間距離計算誤差，從而很好地解決了距離累計計算誤差。Considering the system ' s wide speed range and ipm ' s switching frequency ' s top limit, the variable flux linkage locus structure control has been executed in the full speed adjusting range
考慮到系統調速范圍寬和逆變器開關頻率的限制，在全頻域採用分段變磁鏈軌跡結構的控制方法。In chapter 3, we studied the effect of gaussian transverse profile for the driving and laser fields on lasing without population inversion ( lwi ) in a closed v - type system and an open v - type system. moreover, we discussed also the effect of the unsaturated gain coefficient, the cavity - damping rate, the ratio of the atomic injection rates and atomic exit rate on the corresponding systems. in chapter 4, we mainly discussed the effect of doppler broadening on the gain, dispersion and the frequency up - conversion of the open v - type lwi system and compared the differences and the same between the open system and the corresponding closed system
發現： （ 1 ）在考慮doppler展寬的情況下，通過選取合適的實驗室條件（比如合適的原子環境溫度等）可得到合適doppler展寬值，從而使系統獲得最佳增益； （ 2 ）要想實現系統的頻率上轉換，同時又要獲得足夠強的無反轉激光增益，則系統頻率轉換比不能選取的太大； （ 3 ）對于開放系統，比較小的粒子注入速率比與退出速率對產生無反轉激光是有利碩士學位論文摘要的： （ 4 ）由於dopp1oy展寬的存在，當探測場與驅動場的傳播方向相反時，增益在探測場失諧的某一段區域產生振蕩，且振蕩的振幅、頻率失諧范圍的大小與dopper展寬的取值有關。Engineering drawing has always been labeled as a practical subject. a combination of geometrical, building. mechanical and electrical drawing, it relates between theory and the picture of reality. engineering drawing will provide an accurate and complete ptcture for every object tn terms of shapes and sizes. usually, it is taught using the face - to - face teaching mode even in an odl environment. due to its nature, some students may find difficulty in imagining and interpreting the drawings. however, the availability of sophisticated technology provides the opportunity for the learning of engineering drawing to be enhanced via online. a web - based system for teaching and learning engineering drawing was developed based on a constructivism model. the web - based system is tailored for several topics of engineering drawing such as orthographic projection, sectional view, isometric and oblique drawing at the secondary level. the learning strategy consists of multiple phases beginning with introduction, concept learning, engineering drawing method, application and exercises. during introduction, students will be exposed to an overview of the topic followed by learning of specific concepts. the system provides a learning environment that allows engineering students to view objects from different angles, such as third angle projection and first angle projection as well as views of plans, side and front elevations. after learning about the concepts, students wilt be guided through the various steps in drawing methods for each topic via animations and simulations. learners are able to view any section repeatedly. examples of real application of engineering drawings were also given using graphic, animations and video. to evaluate students understanding, exercises were given at the end of each session
工程制圖一直被認為是一門實踐性學科，其整合了幾何學、建築、力學、電子制圖等，從而將理論與現實圖像聯系起來，工程制圖能為每個不同形狀、尺寸的物體提供精確的、完整的圖像.通常，即使在開放與遠程教育環境中，工程制圖的教學也是通過面對面的教學模式來進行的.由於其特殊性，一些學習者可能難以想象並解釋這些圖像.然而，尖端的技術使得可以通過在線的方式加強工程制圖的學習.研究者基於建構主義模式開發了一個面向工程制圖教學和學習的網路系統.該系統適用於幾種工程制圖，例如展開圖、刻面圖、等角圖和斜角圖.學習過程包括導論、概念學習、工程制圖方法，以及應用與練習等階段.在導論階段，系統為學習者提供了專題簡介，然後是概念學習階段.系統所提供的學習環境允許工程專業的學生從三維透視、一維透視、平面圖、側立面、正立面等不同角度來觀察物體.經過概念學習階段后，系統將引導學生通過動畫和模擬學習每個專題中制圖方法的不同步驟，學習者也能重復觀察任何剖面.另外，還通過圖像、動畫和視頻等方式展示真實的工程制圖應用案例.最後，為了評價學生的理解能力，在每部分內容後面都附有相關的練習The design of excitation power source based on principle of three phase step motor and pulse width modulation ( pwm ) technology, intelligent power model ( ipm ) is used for inverter switches, the output ac pulse used as excitation signals. the speed of rotation and magnetic intensity can be changed by regulate the exciting converted frequency and magnitude of exciting current. constant current is achieved by closed loop feed back
勵磁電源結合步進電機原理與脈寬調制技術，選用智能功率模塊ipm作為逆變開關器件，輸出交流脈沖勵磁信號，以調節勵磁轉換頻率和勵磁電流大小為手段，實現對磁場旋轉頻率和磁場強度大小的有效調節，並通過閉環反饋實現閉環恆流控制。Diode switches or voltage controlled varactors implement dual - band resonators such that they can offer low impedance at the second harmonic of each frequency band, while, in some cases, presenting high impedance at the fundamental frequency as an rf choke circuit
利用二極體開關或電壓控制變容器實施雙頻共振器以提供在雙頻操作中每一個頻段之二階諧波的低阻抗，同時在一些實施例里也提供主頻段的高阻抗、兼具有射頻阻塞電路作用。Their input and output lines should be decoupled at all frequencies, they should be shielded to prevent external electric and magnetic fields from causing interference, and they should be sited as far as possible from sensitive circuits so that residual electric and magnetic fields are prevented by distance from doing serious damage
開關電源的輸入輸出線必須進行全頻段去耦處理；要藉助屏蔽手段抑制電、磁干擾；開關電源要盡可能遠離小信號電路，確保其電磁場對模擬電路影響最低。Secondly, basing on the theory of on - off gain of small signal, the raman gain coefficient for frequency shift between 0. 5 and 20 thz of standard sigle mode optical fiber is measured by pump - probe method through a super luminescent diode ( sld ) as a broadband small signal probe source. thirdly, numerical simulation analysis of gain characteristic of raman fiber amplifier for c band wdm signal light is made according to the raman gain coefficient of the fiber measured before through target and four rank runge - kutta method. at the invariability of wavelength and maximum power of each of two pumps, schematic of powers of two pumps for best flatness on c band wdm optical gain was found out, at the same time, the factors of resulting in gain saturation is analyzed, too
本文首先應用經典的電磁理論對拉曼光纖放大器的工作機制進行了分析，然後，根據小信號理論推導出的開關增益求出了光纖拉曼增益系數的表達式，採用泵浦-探測波的方法，利用超輻射激光二極體（ superluminescentdiode簡稱sld ）作為探測光源，測量了所用標準單模光纖頻移為0 . 5 - 20thz的拉曼增益系數，之後根據所測得的光纖的拉曼增益系數譜對應用該類光纖構成的放大c波段wdm光信號的拉曼光纖放大器的增益特性採用打靶法和四階龍格- - -庫塔進行了數值計算，在給定了兩個泵浦光源的波長和最大功率后，找出了反向泵浦情況下使c波段wdm光源增益最平坦的兩個泵浦的各自最佳功率，同時也分析了導致信號光飽和的原因。This paper introduces the realization scheme and key technology of 2 ~ 12ghz ultra - wideband microwave frequency synthesizer. it adopts dds + pll frequency synthesizer scheme to realize low end frequency 2 ~ 4ghz output, then through segment amplifying multiplying chain realize from 2 ~ 4ghz expand to 2 ~ 12ghz, and the output frequency is selected by microwave switch
採用dds + pll的混合頻率合成方案實現低端頻率2 ~ 4ghz的輸出，再通過分段放大倍頻鏈路實現從2 ~ 4ghz到2 ~ 12ghz的擴頻，並由微波開關控制選頻輸出。Plenty of measures can tell you something about the user ' s state of mind : keystrokes, how many windows are open and their content, whether the user is scrolling, the time of day, the contents of a desktop calendar ? even background noises from a microphone and visual information from a camera
許多測量特徵都可以告訴你有關用戶精神狀態的訊息：鍵盤敲擊，打開的窗口和其中的內容，用戶是否蜷著身子，一天當中的時段，桌面日歷中的內容- - - - - -甚至是話筒中傳來的背景噪音，和攝像頭里的視頻信息。The content of this dissertation include : orthogonal transformation of digital signal ; mathematic model of modulation signals and software - defined radio receiver ; nine feature parameters of the modulation algorithm and threshold of feature parameter ; development procedure of modulation recognition by ccs and the modulation digital signals produced through matlab ; discussion on sampling speed and instantaneous frequency and analysis of experiment " s result
本文給出了在ccs集成開發環境下調制識別演算法模擬實現的程序設計和利用matlab模擬產生調制信號的方法；分析了調制識別演算法的模擬實驗結果；對采樣速率的選取、非弱信號段判決、瞬時頻率的計算以及演算法數據關聯性的簡化等方面進行了研究。分享友人