散度系數 的英文怎麼說
中文拼音 [sǎndùxìshǔ]
散度系數
英文
divergence coefficient-
If the velocity of atoms is near to zero, the light for ces will tend to confine the atoms near to nodes and antinodes. the stability depends on the magnitude of the negative slope of the light force, the depth of the potential well and the momentum diffusion coefficient. it is important to select the parameters, e. g
如果通過激光冷卻能使原子速度降至很小甚至為零,光壓力的作用將使原子被較穩定地囚禁于激光駐波場的節點和反節點處,其穩定程度取決于該處光壓力曲線負斜率的大小、對應勢能的勢阱深度以及動量擴散系數的大小,因此,如何在實驗中合理選擇激光強度、失諧量等顯得尤為關鍵。The origins of dispersion error are analyzed ; effects of initial velocity dispersion, ballistic coefficient dispersion, drift coefficient dispersion, range wind & cross wind dispersion on the ballistic dispersion are discussed
分析了散布誤差的起源,討論了初速散布、射角散布、彈道系數散布、偏流散布、縱橫風散布對密集度的影響。Given the initial conditions including ( 1 ) number density distribution in space which has the similar form to the present day ones, ( 2 ) both the power law and gaussian mass functions for clusters, and ( 3 ) two different velocity distributions which one has a constant dispersion and the other is described by the eddington formula, the dynamical evolution of globular clusters in our milky way galaxy is investigated in detail by means of monte carlo simulations
本文採用與觀測結果具有相同形式的球狀星團空間密度分佈函數,在給定兩種球狀星團系統的初始質量譜(冪律的和對數高斯的)和兩種球狀星團系統的初始速度分佈函數(愛丁頓速度分佈函數和常數的速度彌散度)條件下,我們採用montecarlo的方法對球狀星團系統的動力學演化進行討論。Analyzing the physics structure of vorticity, divergence, vertical velocity, frontogenesis " function, apparent heat source and apparent moist sink etc. indicated the physics fields are favorable for the occurance of the heavy rain over changjiang - huaihe river basin where the physics values are well according to the heavy rainstorm positions ; the low level jet is closely subject to the moisture and the coupled system of the low and the upper level jetstreams induced the strongly " ascending motion ; the intensity of the frontogenesis varies with the development of the rainfall system and reacts the rainfall intensity
主要分析了這次過程中的多種物理量,包括渦度、散度、垂直速度、鋒生函數、視熱源、視水汽匯等,對這一暴雨過程有了比較系統的認識。結果表明:在江淮流域存在著有利於發生暴雨的物理量場配置,渦度、散度、垂直速度等物理量,與暴雨的落區都很吻合的;低空急流的產生不僅有利於水汽的輸送,而且高低空急流的耦合造成了有利於強上升運動的配置;鋒生強度隨著降水系統的發展變化,並影響降水強度。Firstly, the surface characteristic of polystyrene particle is changed from water detesting to water intimity by using special techniques and admixtures so mat the compound quality with inorganic materials is insured. secondly, the contradiction between the weight and strength is solved through optimizing the particle size and using composite fiber and the best heat conductivity is achieved under the condition that the necessary strength is met. in the research process, the author solved the problem of fiber dispersing in insulating materials so that the contraction of the material is controlled
課題研究中,首先採用特殊的改性工藝及外加劑實現對聚苯乙烯顆粒表面的成功改性,使其表面由憎水轉化為完全親水,確保與無機材料的復合質量;其次,通過採用優化骨料級配及使用復合纖維等措施解決了保溫材料的輕質與強度的矛盾,使保溫材料在滿足必要的強度的前提下,導熱系數降至最小;並且,課題研究中成功解決了纖維在保溫材料中均勻分散的問題,達到了抑制保溫材料收縮的目的;最後,通過採用復合外加劑、合適的膠凝材料及合理的配比等措施確保該保溫材料具有良好的和易性,滿足施工的要求。Through the analysis we found that the effect will become more obviously with the increase of thickness or width of superstratum and the decrease of the coefficient of foundation bed ; ( 3 ) anisotropy and nonlinear elastic f. e. m. model has been established and the effect of stress dispersion in compound two - layer foundation was analyzed on the base of the model. from the analysis we can conclude that the coefficient of subsidiary stress dispersion will amplify with the increase of thickness or width or stiffness of back - up coat ; ( 4 ) the formula which can be used in conventional calculation has been deduced for calculating the coefficient of subsidiary stress dispersion and it also has been affirmed to be reasonable through the checking calculation ; the whole theory of compound two - layer foundation has been brought forward in this paper and it ' ll enrich the theory of composite foundation
針對以上問題本文做了以下一些工作並得到若干結論: ( 1 )提出了「復合雙層地基」的概念,並通過工程實例證明此概念的提出有其合理性和必要性; ( 2 )用彈性地基梁理論證實了復合雙層地基確有應力擴散效應,且擴散效應隨上覆硬層厚度、剛度的增加而增大,隨下臥層基床系數的增大而減小; ( 3 )建立了非線彈性、各向異性有限元模型,並以此為基礎分析了復合雙層地基的應力擴散效應,得到附加應力系數隨加固層厚度、寬度、剛度的增加而增大的結論; ( 4 )推導了可用於常規計算的復合雙層地基應力擴散系數公式,並代入工程實例進行了驗證。1. 5 m in diameter ) were dispersed in n46 engine oil with different concentrations using ultrasonic respectively in order to study their tribological properties. the tribological experiments were carried out by mq - 800 four - ball tribometer and mm - 200 ring - on - block tribometer, in which extreme pressure properties, wear scan diameter, friction coefficient and wear volume loss were measured. the results showed that oil containing mos2 nanoparticles had a better wear resistance, friction - reducing and extreme pressure than the oil containing common mos2
將上述制備得到的納米二硫化鉬顆粒和普通二硫化鉬粉末( 1 . 5 m )以不同濃度分散在n46機械油中,在mq - 800四球摩擦磨損試驗機上考察它們的最大無卡咬負荷( p _ b值) 、耐磨性能和摩擦系數;並在mm - 200摩擦磨損試驗機上,通過環?塊摩擦副,比較和分析了它們的摩擦學特性。In this paper, high - order accurate weighted essentially non - oscillatory ( weno ) schemes are investigated and their applications in hyperbolic conservation laws are discussed. based on this, a new weno difference scheme which based on dispersion - relation - preserving relation is developed, and representative test cases with this scheme for computational aeroacoustics ( caa ) problems has been implemented and compared in order to test capability of wave capturing ; in addition, weno schemes generally do not converge at high order in the presence of contact discontinuity of euler equations, so a conservative front tracking technique coupling weno schemes and level set method to simulate the translating density profile is presented here, and numerical simulation with this technique for representative test case has been implemented and results show the desired accuracy
本文研究了高階精度加權基本無振蕩( weno )格式及其在雙曲守恆律方程中的應用,在此基礎上作了兩個方面的工作:一是針對高頻聲波問題構造出一種基於保色散關系( drp )的weno有限差分格式,並對計算氣動聲學( caa )問題的代表性算例進行了大量數值實驗,比較了該格式捕捉波數的能力;另外,針對高階weno格式在處理euler方程的接觸間斷時精度有所降低的問題,研究了利用界面追蹤技術levelset方法和高階激波捕捉weno格式相結合的一種守恆追蹤方法,並且給出有代表性的密度滑移面問題的算例,得到一致高階精度的數值模擬結果。The third model was designed to investigate atom diffusion at contacting point. fe was sintered at 500, 550 > 600, 650 > 700 under bpec and radiation heating. the test results of image processing indicated that the average pore size took on wavelike with temperature under bpec heating
脈沖大電流加熱條件下,其它條件相同時,分別在800 、 900的溫度武漢理土大學碩士學位論文下擴散連接cu絲和ni絲,結果表明接觸線處cu和ni的擴散系數隨溫度的升高而增大。Validation of the presented approach is verified through numerical simulations of radar measurements over the bare soil surfaces
本研究以裸露土之土壤?度及其雷達散射系數的數值模擬來驗證此一方法之有效性。For parameter a, there is a close relationship exist between a ( 9, sr ) in two different radar incident angle that can be expressed as : with considering the effects of soil texture, we get the final expression of the inversion model : where mv ( t1 ), mv ( t2 ) is volumetric soil moisture content in two different temp, c, d is soil type related parameters, and v ( t1 ), s ( t2 ) is coresponding bare soil radar backscattering coefficients. inversion results show that for the c band hh polarized radarsat scansar data with a range of incidence angle from 20 to 40, the soil moisture change value can be derived with an acceptable accuracy using the above model. the temporal and spatial soil moisture change patterns are associated with rainfall and vegetation cover, as well as the soil hydraulic characteristics
利用最新發展的電磁波散射模型研究了不同植被覆蓋地表雷達波對地表土壤水分的敏感性,建立了半經驗植被雷達後向散射模型; 2 ) .研究發現在農作物等矮小植被覆蓋地表,植被層直接後向散射與植被類型相關,且在植被生長期,雷達後向散射系數對植被含水量的敏感性要高於對植被高度變化的敏感性; 3 ) .解決了單參數雷達地表土壤水分反演問題中,雷達入射角和地表粗糙度的影響這一難點問題; 4 ) .利用土壤介電模型校正了不同土壤類型對反演地表土壤體積含水量的影響; 5 ) .在以上成果基礎上,建立了完整的單參數雷達地表土壤水分變化探測反演演算法,經地表驗證,模型反演地表土壤水分變化值的精度為rmse = 0Sellmeier coefficients for the refractive indices of calcite at crystal different temperatures
冰洲石晶體色散方程解析研究及折射率溫度系數表達式This technique is mainly involved two steps : 1 ) vegetation effects correction : we used ndvi ( normalized difference vegetation index ) derived from tm and avhrr measurements for spatial and temporal variations of vegetation covers at different scales
但由於電磁波與地表相互作用的復雜性,雷達後向散射系數除受地表介電常數(土壤水分)影響外,還受到地表粗糙度、土壤類型、植被覆蓋以及雷達入射角、頻率、極化等多種因素的影響。2 ) radar incidence angle and surface roughness correction : to make radar incidence correction and eliminate the surface roughness effects, a wide range of surface parameters ( soil moisture, surface rms height, correlation length, incidence angle ) was input to the ibm model to simulate the effect of surface roughness and radar incidence angle on the sensitivity of soil moisture to the radar backscattering coefficient. a simple model was established to simulate the effects of incidence angle and surface roughness. 3 ) establishment of soil moisture change inversion model : according to a modified ibm model simulation results, the bare surface backscattering coefficients can be expressed as a funtion of the dielectric component for a given surface roughness when the surface slope greater than 2. 0, which is valid for most nature surface : in above equation, r0 is the surface reflectivity at normal incidence
本研究中,首先利用基於微波輻射傳輸方程的微波植被模型和積分方程( iem )模型模擬了各種地表土壤水分含量情況下,植被覆蓋、地表粗糙度(包括地表均方根高度和相關長度) 、雷達入射角對c波段(頻率4 . 7ghz )水平極化( hh )雷達後向散射系數的影響,在此基礎上,建立模型消除了植被覆蓋、地表粗糙度、及雷達入射角對雷達後向散射的影響,利用多時相50m解析度radarsatscansar雷達後向散射系數圖像反演得到了地表土壤水分變化模式信息。Some basic concepts, failure criterion, formula and determination of analytical parameters such as spring modulus, coefficient of damping and time step of the extended model are presented
文中詳細介紹了離散單元法的基本原理、破壞準則、基本方程以及彈簧剛度系數、阻尼系數、時間步等計算參數的確定方法。This paper proposed a multizone and multidimensional radiation heat transfer model of g4135 diesel engine, including a combustion chamber space zone - model, a radiate temperature model, a radiate emission coefficient and an absorption coefficient model
摘要對g4135直噴式柴油機建立了一個輻射多區多維模型,包括缸內工質的幾何空間模型、輻射溫度模型、輻射發射系數、吸收系數以及燃料油滴的散射系數模型。In this study, we demonstrate a technique using the multi - temporal c band hh polarized radarsat scansar data to estimate the relative soil moisture change. the experiment data from sgp97 covered a whole range of vegetation growing season and different type agriculture fields
研究證明,星載合成孔徑雷達( sar )得到的地表後向散射系數與地表介電常數有直接相關關系,從而能夠在水文模型要求的精度范圍內有效提取地表土壤水分信息。The new concepts, such as the active supporting coefficient, the coefficient of strength utilization, the coefficient of pretensioned bolt length, the effective compressive zone, the coefficient of pretensioned stress diffusion, the framework and mesh structure of the effective compressive zone, and the critical supporting stiffness were put forward
提出錨桿主動支護系數、強度利用系數、預應力長度系數、有效壓應力區、預應力擴散系數、有效壓應力區骨架網狀結構及臨界支護剛度等概念。The relationship of the moisture content and radar scattering coefficient is built into the measurement equation, while the dry - up ( or wet - down ) of soil moisture in multi - temporal states was modeled into the process equation
土壤濕度與雷達散射系數間的對映關系是以量測方程序來表示,而土壤濕度在時序上漸干或漸濕的狀態變化則以處理方程序來表示。The multi - magnet suspension system of maglev is a multi - input and multi - output correlation control system in essential. but generally, the structure of modern maglev vehicle is modularized, and the spring stiffness of the second suspension is small, such structure can resolve mechanistic coupling of vehicle. so the methods of separate control are used very common in maglev suspension control systems
磁浮列車的多磁鐵懸浮系統實質上是一個多輸入、多輸出的相關控制系統,但是現在的磁浮列車車輛一般採用模塊化結構,而且二次懸掛彈簧的剛度系數較小,可以實現機械解耦,所以在控制系統中,往往採用分散控制的方法。分享友人