晶體中的能帶 的英文怎麼說
中文拼音 [jīngtǐzhōngdenéngdài]
晶體中的能帶
英文
energy bands of crystal-
Due to the hardware characteristic ' s limitation, such as the poor speed of a / d, d / a conversion and dsp process, the most part of sr system adopt middle course. that is to say, by using the special digital converter or running relevant arithmetic, it converts the radio signal to intermediate frequency signal and completes the base - band signal process that is n ' t the veriest sr and is named " software defined radio ( sdr ) "
由於受到硬體性能如a d 、 d a及dsp晶元處理速度的限制,目前的軟體無線電系統多採用折中的實現方案,增加專用的數字變頻器或者運行數字變頻演算法,將射頻信號變頻到中頻,然後再進行基帶信號處理,這樣的軟體無線電系統又被稱之為「軟體定義無線電」 ,它並不是真正意義上的軟體無線電。In this paper, researches based on one - - dimen - sional photonic cystal and its app1ications are developed. in theory, the finite - - difference time - - domain ( fdtd ) method is re - searched
在理論工作中,研究了時域有限差分法理論,利用時域有限差分法建立了研究一維光子晶體能帶結構的模型。A patch antenna with etched holes on the ground plane is also studied. the performance of the antenna at the resonant frequency is analyzed by using the fdtd method together with the pml boundary treatment. the results show that the surface waves are suppressed greatly, the bandwidth is improved and a 1 odb reduction on the sidelobe level is achieved at the 110 and 260 directions in the e plane
全面地研究了地面腐蝕周期圓孔結構的電磁晶體貼片天線在基波頻率處的性能,用fdtd方法並結合pml邊界處理技術對該天線所取得的研究結果顯示,本文設計的地面腐蝕型電磁晶體結構抑制了貼片天線中的表面波,增加了天線的帶寬,並有效地削弱了旁瓣,使天線的e面方向圖上110和260方向的兩個旁瓣被削弱了10db 。Abstract : we have studied the spontaneous emission from a three - level atom with an external - driving field in a photonic crystal. as a result of quantum interference and photon localization, the population in the two upper levels displays quasi - oscillatory oroscillatory behavior. this depends on the initial atomic state and the relative positions of the two upper levels from the forbidden gap. the intensity and the phase of the external field can affect spontaneous emission from the atom. the properties are different from a three - level atom either in vacuum or in aphotonic crystal without an external driving field
文摘:討論了在雙光子驅動場作用下,三能級原子在光子晶體中的自發發射問題.由於量子干涉和光的局域化作用,兩個上能級中的占據數將具有周期振蕩或準周期振蕩的性質,這不僅依賴于兩個上能級與禁帶的相對位置,同時也依賴于原子的初始狀態,而且還與驅動場的強度、驅動場的入射位相有關.這些性質既與真空中帶有驅動場的原子的自發發射性質不同,也有別于無驅動場作用下光子晶體中三能級原子的自發發射性質Such control can be realized in case where a atom interact with photonic band gap matericals when the atom is placed in photonic crystals whose density of modes is dramatically different from that of free space vacuum. it was known that control could be achieved by varying the frequency ( which leads to the changes of the relative position of the upper levels from the forbidden gap ) or by varying the photonic density of modes ( dos ) or by varying the intial atomic state
由於光子晶體具有不同於真空中的光子態密度,原子和光子帶隙材料便發生相互作用,這樣便可以控制原子的自發輻射。改變原子上能級與光子禁帶邊緣的相對位置、材料中的光子態密度或原子初態都可以控制原子的自發輻射。A patch antenna with air holes in the substrate has been designed. the finite - difference time - domain ( fdtd ) method together with the perfectly matched layer ( pml ) boundary treatment has been used to study the performance of the antenna. it is shown that the surface waves are significiently suppressed, the frequency bandwidth is improved, the sidelobe levels are reduced and consequently the gain in the forward direction is improved by 14 db ( about 4 db higher than the value reported previously )
設計了一種基底鉆周期圓孔結構的電磁(光子)晶體貼片天線,用fdtd方法並結合pml吸收邊界條件對該天線進行了研究,結果表明本文所設計的基底鉆孔型電磁晶體貼片天線取得了多方面的性能改善,與普通天線相比,基底中的表面波受到很大抑制,天線的帶寬增加,遠場方向圖上天線的旁瓣和背瓣被明顯削弱,向前輻射的增益由原來的12db增加到26db ,增加了14db ,比文獻上報道的gonzalo等人的研究結果提高了4db 。Bringing into play the communication market resources in hangzhou bay, the park devotes itself to the formation of a “ mobile valley ”, which means a unique zhejiang - flavored economic pattern : forming a complete telecommunication industry chain from software and operation development of key parts, such as ic chip, rf modules, base band, display, high capacity battery, to related components like cell phone housing, keypad, antenna, vibration motor, mould, pcb ( circuit board ), photoelectricity device, electronic device, connectors and system and software development, and operation service development
園區依託杭州灣通信市場資源,致力打造「移動谷」 ,創造中國浙江經濟特有的專業版塊模式:從集成電路晶元、 rf組件、基帶、顯示器、高能電池等核心器件到接手機外殼和按鍵、天線、振動馬達、模具、 pcb (電路板) 、光電器件、電子器件、連接件等相關組件及系統和軟體開發、運營服務開發,形成完整的通信產業鏈。The band was previously associated with f - type color centers and v - type color centers, as analyzed in x - ray irradiated ysz sample. however, the absorption band observed in our experiments has a shift towards the longer wavelength ( red shift ) as comparing with that in the x - ray or neutron irradiated ysz spectra. this shift may mainly due to large local distortions near the f - type centers and the v - type centers and the presence of multiple color centers
本文通過光吸收、光熒光、 tem 、 xps測試及trim96計算分別研究了不同注量xe ~ +注入ysz前後光學性能和缺陷形態變化,以及ni ~ +注入對不同摻雜單晶al _ 2o _ 3結構和光學性能的影響,得到以下結果: ( 1 ) ysz注量達到10 ~ ( 16 ) cm ~ ( - 2 )時,開始出現由f型和v型色心重疊而產生的吸收帶,與x射線、中子輻照相比,重離子輻照產生了更為復雜的缺陷復合體而導致吸收峰紅移。On - line monitoring of hvcb is the precondition of predicting maintenance, is the key element of reliable run, and is the important supplement to the traditional off - line preventive maintenance in fact, the faults are made by hvcb, no matter in number or in times, is over 60 % of total faults so it has determinative importance for improving the reliability of power supply and this can greatly decrease the capital waste used by - dating overhaul in this paper, the inspecting way of hvcb mechanism characteristic is discussed the concept of sub - circuit protector is presented, the scheme that we offered has been combined with sub - circuit integrality monitoring theory, to ensure that it has the two functions as a whole according the shut - off times at rated short circuit given by hvcb manufacturer, the electricity longevity loss can be calculated in each operation, and the remained longevity can be forecast too an indirect way for calculating main touch ' s temperature by using breaker shell temperature, air circumference temperature and breaker ' s heat resistance is improved in this paper, and main touch resistance can be calculated if providing the load current msp430, a new single chip microcomputer made by ti company, is engaged to develop the hardware system of the on - line monitoring device, and special problem brought by the lower supply voltage range of this chip is considered fully
高壓斷路器所造成的事故無論是在次數,還是在事故所造成的停電時間上都占據總量60以上。因此,及時了解斷路器的工作狀態對提高供電可靠性有決定性意義;並可以大大減少盲目定期檢修帶來的資金浪費。本文論述了斷路器機械特性參數監測方法;提出了二次迴路保護器的概念,並將跳、合閘線圈完整性監視和二次迴路保護結合起來,給出具有完整性監視功能的二次迴路保護器實現方案;根據斷路器生產廠家提供的斷路器額定短路電流分斷次數,計算每次分閘對應的觸頭電壽命損耗,預測觸頭電壽命;提出根據斷路器殼體溫度和斷路器周圍空氣溫度結合斷路器熱阻來計算斷路器主觸頭穩態溫升的方法,並根據此時的負荷電流間接計算主觸頭迴路的電阻;在硬體電路設計上,採用美國ti公司最新推出的一種功能強大的單片機msp430 ,並充分考慮該晶元的適用電壓范圍給設計帶來的特殊問題;在通信模塊的設計中,解決了不同工作電壓晶元之間的介面問題,並給出了直接聯接的接線方案。The fabrication of the nano - structures and the study of nanoelectronic devices ( single electron transistor - set, single electron memory, etc. ) are one of the most important projects of the nanoelectronics and nanotechnology, of a study field with most vitality, progressive future, and it may bring magnitude effect to new technology revolution and industry in future
納米結構的制備和納米電子器件(單電子晶體管、單電子存儲器等單電子器件)的研究是納米電子技術中最重要的研究內容之一,是最具有生命力、最具有發展前途,對未來新技術革命和產業可能帶來革命性作用的研究領域之一。Topics covered include : crystal lattices, electronic energy band structures, phonon dispersion relatons, effective mass theorem, semiclassical equations of motion, and impurity states in semiconductors, band structure and transport properties of selected semiconductors, and connection of quantum theory of solids with quasifermi levels and boltzmann transport used in device modeling
被覆蓋的論題包括:晶格、電子能帶結構、聲子色散關系、有效質量理論、半經典運動方程和半導體中的非純態、選擇性半導體的帶結構和輸運性質固體量子理論與準費米能級以及用於器件建模的玻爾茲曼輸運理論之間的聯系。Nanoscale semiconductor metal selenides and tellurides have attracted substantial research interests during the past years. it has been demonstrated that the optical, electrical and magnetic properties of them could be tailored in a controllable way by altering their structure, morphology, dimension, or composition
如何在合成過程中實現對它們的晶體結構、維度、形貌、表面結構和能帶結構的調控,將為實現材料性能的人工剪裁,深入系統研究材料結構與性能的關系具有重要的意義。When the channel changes rapidly, this proposed dynamic algorithm is efficient. other than above, this paper also studies the character of ofdm under multipath fading and gives the baseband computer simulation by systemview. at last, it performs ofdm dsp hardware plug - in simulation
利用systemview軟體進行模擬多徑通道下ofdm系統性能模擬,並探討了模擬過程中的一些問題,最後搭建了ofdm基帶模擬系統,並利用tms320c54dsp晶元,進行了ofdm硬體嵌入式模擬。In experiments, the energy band structures of l - - d pc and 1 - - d pc sl are researched. we get the relation between the band gap width and the num - ber of the iayers, dielectric indices contrast, midgap wave - - length
在實驗工作中,研究了一維光子晶體的能帶結構,得到了帶隙寬度隨介質層數、介質折射率、中心波長變化的關系曲線。There is also energy band structure for photons in photonic crystal, which is similar as that for electrons in natural crystal ( electronic crysta1 ). localized state will ap - pear if there is an impurity or defect
光子晶體中的光子與一般晶體(電子晶體)中的電子相似,都有能帶結構,都會因為有雜質和缺陷態的存在而存在局域態。In 1987, a remarkable step was made by yablonovitch, who pointed out the possibility of the realization of photonic bandgaps, localized defect modes, and their applications to various optoelectronic devices, and by john who dicussed the strong localization of electromagnetic waves in disordered photonic crystals and also predicted many interesting quantum optical phenomena that can be realized in photonic crystals such as the bound state of photons and non - exponential decay of spontaneous emission
1987年yablonovitch和john開創性地提出光子晶體這一新概念, yablonovitch指出了有可能實現光子頻率帶隙和局域缺陷模以及許多光電技術方面的應用, john則討論了在無序光子晶體中電磁波的強烈局域現象,並預言在光子晶體中存在許多有趣的量子光學現象,諸如光子局域態、自發輻射的非指數衰減。In addition, the control of spontaneous emission of a three - level atom embedded in photonic crystals was investigated in this paper, because the model of two - level atom is siple. as it shows, the properties of spontaneous emission depend not only on the relative position of the resonant frequency from the edge of the photonic band gap and the photonic mode density but also on the intial atomic state
二能級畢竟是最簡單的模型,故在最後,還對光子晶體中三能級原子的自發輻射特性進行了研究。結果表明,其自發輻射除了依賴于原子上能級與光子頻率帶隙邊緣的相對位置或光子態密度外,還依賴于原子的初始狀態。The development of microelectronics ? first the transistor and then the aggregation of transistors into microprocessors, memory chips and controllers ? has brought forth a cornucopia of machines that manipulate information by streaming electrons through silicon
微電子學的進展已經帶來豐碩的成果,讓機器能夠藉由流過矽片的電子來處理資訊;在這進展的過程中,先是出現電晶體,然後把許多電晶體聚集起來,製作出微處理器、記憶體晶片以及控制器等。分享友人