譜密度級 的英文怎麼說
中文拼音 [pǔmìdùjí]
譜密度級
英文
spectrum density level-
After processing, the sensitometrically exposed step wedge is read on a densitometer and the data is plotted.
加工完畢后，即用密度計對試驗膠上復制的階梯級譜的密度進行測定，然後用測得的數據作圖。Abstract : the effect of correction of self - consistent potential on electronic structure in simple cubic nanocrystal particles is calculated by means of the green ' s function method in the tight - binding approximation, taking only the nearest neighbor matrix elements into account. the numerical results show that the electronic energy spectrum is shifted, the chemical potential is not equal to the atomic energy level, the electronic density at each lattice point is changed, and the variation of electronic density at surface lattice point is the largest
文摘:在緊束縛近似下，只計及最近鄰的矩陣元，採用格林函數計算了自洽勢修正對簡立方納米晶體顆粒的電子結構的影響，發現電子能譜發生了移動，化學勢不等於格點原子能級，各格點的電子密度也發生了變化，其中以表面格點的電子密度變化最大。The entropy or number of states of system or subsystem are closely related to interaction of particles and energy level distribution, therefore, to study the temperature dependence of the specific heat may supply some important and useful microscopic information which may play an important role in understanding electronic structure, density of state, phonon spectrum etc. the specific heat measurements at low temperatures also play important roles in the finding of the third law of thermodynamics, the quantum theory of solid and bcs theory for superconducting etc. moreover, specific heat measurements help us to understand the different kinds of phase transitions ( such as : structural phase transition, magnetic phase transition, superconducting phase transition etc. ) and the scaling behavior near the critical point
系統、子系統的熵或微觀狀態數與微觀粒子間的相互作用及能級分佈密切相關，因此研究比熱與溫度的依賴關系能夠提供被測量系統許多極其有用的微觀信息，對理解固體的電子結構、電子態密度、聲子譜等起著十分重要的作用。低溫比熱的測量和研究對熱力學第三定律、固體量子理論和超導bcs等理論的建立起到了積極的推動作用。比熱研究還有助於認識各類相變如結構相變，磁性相變，超導相變等及臨界點附近的標度規律。When the energy distribution of secondary neutron are represented by evaporation spectrum ( lf = 9 ), care must be taken in describing the nuclear temperature near the threshold
通過分析發現，評價次級中子能譜數據所採用的蒸發譜模型大都忽略了能級密度參數與激發能之間的關聯。Expanding the system ' s hamiltonian to a real symmetric matrix in an appropriate orthogonal basis vector and then diagonalizing it, we get the energy spectrum of the system and calculate the energy level spacing distribution function and the spectral rigidity. then we study the statistical character of the energy spectrum under the changing of magnetic field intension and find that the system ' s motion transfers from regular to chaos gradually
將系統的哈密頓量在一個適當的正交基矢下展開並對角化，得到系統的能譜，分別計算系統能譜的能級間距分佈函數和譜剛度，研究了該系統量子能譜的統計特徵隨磁感應強度大小的改變而表現出的系統運動由規則到混沌的漸進變化。An investigation of the rijndael algorithm which is the advanced encryption standard of usa is taken in this thesis. we have focused on developing the cryptographic properties of the rijndael sbox from the viewpoint of boolean function, walsh spectrum and algebraic structures, on the attacks against the reduced variants of rijndael, and on the optimized implementations of rijndael. the key contributions follow below
本文對美國高級加密標準rijndael演算法進行了比較深入的研究，內容包括：從布爾函數、 walsh譜和代數結構的角度對其s盒密碼性質進行的研究，簡化演算法的攻擊方法以及演算法的優化實現問題，主要成果有： 1 、提出求解布爾函數表達式的兩種新方法，具有簡潔、易於編程實現、準確而快速的特點，應用於des演算法獲得與公開文獻相符的結果，應用於rijndael演算法首次求出其s盒布爾函數表達式。None but is the test spectrum abundant and controllable, it is possible to simulate the stresses environment needed for exposing weakness of the product. based on summarizing the present status of the vibration test and vibration environment simulation technology in the world, the topic of simulation of super - gaussian random vibration environment with controllable frequency spectrum and its applications in reliability enhancement testing is put forward. the main content and conclusions of the dissertation are as following : 1
本文在綜述國內外振動試驗技術和振動環境模擬技術的基礎上，引出「頻譜可控的超高斯隨機振動環境模擬技術及其在可靠性強化試驗中的應用」這一主題，並緊緊圍繞該主題開展了如下研究工作: 1 .全面分析了振動激勵的功率譜密度量級、幅值分佈、帶寬以及試件結構的固有頻率、阻尼比等因素對疲勞損傷累積的強化效應，提出振動強化試驗激勵信號應具備的重要特性:頻譜可控和超高斯，確立了本文的研究主題和方向。A sorting method of the helicopter noise sources is given. the temporal waveform and spectrum of the noise signature is analyzed. at last, the sound pressure spectrum density level is estimated with the experimental data taken from a specific navy helicopter
扼要闡述了直升機噪聲的產生和分類，考察了直升機信號的波形和頻譜特徵，並對特定的直升機噪聲的聲壓譜密度級進行了計算。The principles of sigma - delta modulator have been discussed firstly and the influences of structure and parameters on resolution have been analyzed. then on the base of theories, the simulink toolbox of matlab has been used to make behavior simulation and fft analyse of two main structures : 2 - 1 - 1 and 2 - 2. the related parameters of modulator such as : psd, sndr and enob have been gotten by simulink toolbox on the conditions of different oversampling rates. from the analyses above, topology of modulator has been chosen
調制器的原理進行了介紹，分析了各種結構及參數對調制器精度的影響;其次，在理論指導的基礎上，利用matlab的simulink工具包對調制器兩種主要級聯結構: 2 - 1 - 1和2 - 2結構進行了行為級模擬和fft分析，得出了在不同過采樣率條件下，兩種結構調制器的功率譜密度、信噪失真比以及有效位數，通過比較確定了調制器的拓撲結構。Moreover, close - form expressions for the power spectral density and acpr of cdma signal passed through a nonlinear power amplifier are derived using the power series and statistical model of cdma signal. the comparison computer between algorithm simulation and practical data or experimental data derived using ads proves the validity
同時基於cdma信號的時域數學模型和功率放大器的冪級數模型，具體推導出cdma信號的功率譜密度和acpr的數學表達式，並將其演算法模擬結果與實測結果以及ads實驗模擬結果相比較，驗證其正確性。分享友人