頻率倍增 的英文怎麼說
中文拼音 [bīnlǜbèizēng]
頻率倍增
英文
frequency multiplication-
The methods of direct measurement with low precision such as frequency and time interval methods and the methods of indirect measurement with high precision such as beat frequency method, dual mixer time difference method and frequency difference multiplying method are supported on the platform. the fundamentals of each method are studied. the quantization error is analysed and the illustration is given for each method
該平臺支持直接頻率和時差法兩種較低精度的測量方法以及雙混頻時差法、差拍頻率法和頻差倍增法高精度的簡接測量方法,本文研究了各種測量方法的原理,對各種測量方法的量化誤差作了分析,並給出具體的實例。Ceviar living cells, which undergo devision 200 times faster than normal cells, contain a great variety of activated factors that stimulate fission of both organism and cells, and regeneration of cells, improving micro circulation and supply of nutrients, reducing melanin, and thus growing vitality and skin springiness, resulting from less wrinkles and shrinking pores
魚子活細胞有旺盛的生命力,它的細胞分裂頻率比成熟細胞強200倍,內含多種活性因子,可啟動人體組織細胞的分裂和活化,刺激老化細胞更新再生,改善微循環,淡化黑色素,其高分子蛋白質有效的補充人體細胞和皮膚細胞的養份,增強機體活力和皮膚的彈性,修護鞏固基底層細胞組織達到去除皺紋、收緊毛孔、提升皮膚的顯著美容效果。To enhance the system reliability, the sample frequency of the digital correlator is four times as much as that of the pn code
為了增加系統工作的可靠性,本系統採用4倍于偽碼速率的采樣頻率。Firstly, we analyze the character of nd : yag, bbo and lbo, for nd : yag crystal and select the nd : yag as the gain medium and lbo as doubling - frequency crystal. ln the theory, analyzing the parameter of the gain medium length, the ratio of the pump - and laser - beam waists. based on the above analysis, we design the resonance cavity
首先,我們對增益介質的性質和非線性晶體bbo和lbo的一些性質進行了比較,選取nd : yag作為增益介質, lbo作為倍頻晶體。理論上分析了激光器設計中的一些參數值,如增益介質長度、模式交疊率、最佳倍頻條件,並根據理論分析結果設計了諧振腔。According to the guidline, two nd : yag lasers have been designed and set up, one is end - pumped by lower output power ld using a selfoc micro lens, and the other is end - pumped by high output power ld using a pair of lenses are designed, and the characteristics such as output power and power stabilization of both solid - state lasers are investigated. thirdly, when an empty liquid crystal cell is inserted in the cavity of the nd : yag laser pumped by high power ld, the laser can operates in single axial mode. finally, according to the relationship between the laser output power and the longnitudinal a ld - end - pumped nd : yag laser sensor for displacement measurement has been investigated theoretically and demonstrated experimently, the results indicate that when the mean radius of pumping inside the laser cavity is far less than that of the oscilating laser mode, the exponential of the output power is a gauss function of the longitudinal positon of focused spot of ld pumping beam, both the measurement range and the sensitivity are dependent on the incident pumping power, as the incident pumping power is increased, the measurement range is enlarged and the sensitivity is improve d
本文首先介紹了ld泵浦nd : yag激光器的發展狀況、主要特性及其應用,從四能級速率方程出發,推導了ld泵浦nd : yag激光器的閾值、輸出功率和斜效率的表達式,並簡述了激光器的工作原理、結構型式和倍頻方法;其次,以空間相關的速率方程為基礎,提出了ld端面泵浦nd : yag激光器的設計方法,給出了一定泵浦耦合方式下,振蕩光模尺寸、最佳輸出耦合率、泵浦光模尺寸、泵浦光焦斑位置等參數的選取依據,以此為依據,設計了自聚焦透鏡耦合小功率ld泵浦nd : yag激光器和透鏡組耦合高功率ld泵浦nd : yag激光器,對激光器的輸出功率和功率穩定性等特性進行了實驗研究;再次,在帶尾纖輸出的高功率ld泵浦nd : yag激光腔內插入一隻空液晶盒,觀察到了激光器以單縱模運轉;最後,根據泵浦光焦斑端面位置對激光輸出功率的影響規律,提出了ld端面泵浦nd : yag激光位移傳感新方法,並進行了理論和實驗研究,研究結果表明:當激光晶體內泵浦光平均光斑半徑遠小於振西安理工大學碩士學位論文蕩光束腰半徑時,激光輸出功率的自然指數與泵浦光焦斑的縱向位置成高斯變化規律,測量范圍和靈敏度依賴于泵浦功率,隨著泵浦功率的增加,測量范圍擴大,靈敏度提高,當端面泵浦功率為7 . 24w (最大輸出功率為1 . 926w )時,激光位移傳感器的測量范圍和靈敏度分別是13 . 045mm和0 . 148mw / pm 。One forward optical receiver module takes one slot, after power double - amplification inside, send out 1 way rf signal 104dbuv and 1 way level checking signal, or two - distribution output
一個正向光接收器模塊佔一個槽位,內置功率倍增放大,輸出1路射頻信號104dbuv和1路電平檢測口,或二分配輸出Multiband transmission permits a reduction in error probability in exchange for at least a twofold increase in bandwidth and carrier power
多頻帶寬傳輸能降低誤差概率,但其代價是速度及載波功率至少增加一倍The influence of various waterpower and configuration parameters on heat transfer is analysed and the rules of convective heat transfer coefficient and the ratio of heat transfer enhancement with mass flux are obtained. at the same time, we gain important results as below : as for resonance chamber with certain configuration, self - oscillation can be generated under suitable configuration and waterpower parameters. for the same configuration resonance chamber, the intensity of the self - oscillation is changed by the waterpower parameters
當流量及壓差降低至一定程度時,共振腔還可能削弱換熱;加熱功率的提高會增加流體(水)的溫度,流體的粘度會隨著降低,這會減少對流體脈動的阻礙,使脈動衰減得更慢,而脈動幅度的增加會增強換熱,故加熱功率對有脈動的對流換熱是有影響的;自振腔產生的流體脈動頻率是自振腔固有頻率或其整數倍,流體脈動頻率過高或過低都不利於對流換熱,存在一有利於強化換熱的頻率范圍。Spatial frequency multiplexing
空間頻率倍增As dab system serves an area by using one single frequency network, more radio services are available alongside with data and pictures transmissions. this significantly expands the number of channels and allows for a more efficient use of the available spectrum as well as more interactions with audience
由於數碼聲音廣播支援單頻網路的運作,即全港均用單一頻率發射及接收,可以大幅節省頻譜,從而提供更多電臺服務,以及傳輸數據和影像等由於更有效運用廣播頻譜,電臺頻道數目將可倍增,而服務也可多元化。As dab system serves an area by using one single frequency network ( sfn ), more radio services are available alongside with data and pictures transmissions. this significantly expands the number of channels and allows for a more efficient use of the available spectrum as well as more interactions with audience
由於數碼聲音廣播支援單頻網路的運作,即全港均用單一頻率發射及接收,可以大幅節省頻譜,從而提供更多電臺服務,以及傳輸數據和影像等;由於更有效運用廣播頻譜,電臺頻道數目將可倍增,而服務也可多元化。Because of the affection of noise and signal fading, in order to high data rate access and high quality, wireless communication need new technology to improve the link reliability and enhance the spectrum efficiency. mimo ( multiple input and multiple output ) can enhance the spectrum efficiency and increase channel capacity greatly, and reduce the multipath affection without spectrum band and power increasing. the 3th generation mobile communication wcdma is coming, with the purpose of putting mimo, stbc ( space time block coding ), space diversity into practice of wcdma systems, in order to lay the foundation of 3g toward 4g, this dissertation has done some research under this background
在發射機和接收機使用多個天線進行數據傳輸的多輸入多輸出( mimo )技術,可以在不增加帶寬和天線發送功率的條件下,成倍的提高頻譜利用率,提高系統的通道容量,還可以抗多徑干擾。第三代移動通信wcdma即將到來,為了將多天線技術( mimo ) ,空間分集技術,空時編碼技術用到wcdma系統中去,為第三代移動通信向第四代移動通信系統平穩過渡奠定一定的基礎,需要做一些理論上的研究。Fortunately, a novel creative technology, namely multiple - input multiple - output ( mimo ), has provided an innovative solution to this problem. mimo technology utilizes multiple antennas at both transmit and receive ends of the radio link to multiply the capacity and reliability by fully exploiting the space resource within the same frequency band at no additional power expenditure
可幸的是,多入多出( mimo )無線通信技術為解決該問題提供了全新的途徑,它在無線鏈路收發兩端均採用多天線,充分開發空間資源,在無需增加頻譜資源和發射功率的情況下,成倍地提升了通信系統的容量與可靠性。On the rotor blade pressure surface, the dominant frequencies of unsteady surface pressure are the up - stream blade wake passing frequency and its harmonics, and the amplitudes of pressure fluctuations decrease from leading edge to trailing edge
轉子葉片吸力面非定常壓力受葉片附面層和上游葉片尾跡共同影響,其主導頻率為上游葉片尾跡頻率及其倍頻,但是在吸力面前部氣流加速區壓力波動幅度沿流向增大,而在吸力面後部氣流減速區壓力波動幅度沿流向減小。The vibration resistant performances of the parts that made o f pc are five times higher than that of casting iron, but weight is o ne third of it at the same volume. the thickness of the sfpc parts can be increased if the weight is equal. this would make natural fr equency and the amplitude of vibration reduced and improve the dy namic characteristics of a machine tool
用此種材料製造的部件,從減振性能來看,超過鑄鐵的5倍,相同體積下重量只有鑄鐵的1 3 ,在不增加其重量的情況下,壁厚可增大,使固有頻率提高,共振振幅減小,靜動剛度提高,改善了機床的動態性能。分享友人