constant adj. 1.恒定不變的,固定的,穩(wěn)定的,恒久的;繼續(xù)不斷的。 2.不屈不撓的,堅韌的。 3.忠實的,有節(jié)操的。 be constant in love 忠貞不渝的愛情。 two days of constant rain 兩天接連下雨。 constant to one's duty 忠于職守。 constant wind 恒風(fēng)。 n. 【數(shù)、物】常數(shù),恒量;恒定(值);(常)系數(shù),率;【語法】(轉(zhuǎn)換語法用語)定項。 the circular constant圓周率。 adv. -ly
structure n. 1.構(gòu)造,結(jié)構(gòu);組織;石理,石紋。 2.建造物。 3.【化學(xué)】化學(xué)結(jié)構(gòu)。 4.【心理學(xué)】(直接經(jīng)驗中顯現(xiàn)的)結(jié)構(gòu)性,整體性;整體結(jié)構(gòu)。 military structures 工事。 adj. -d ,-less adj.
Phenomenal analysis of fine structure constant 發(fā)生改變的唯象分析
These energy levels are determined by how tightly the atomic nucleus holds the electrons , which depends on the strength of the electromagnetic force between them ? and therefore on the fine - structure constant 能階是由原子核拉住電子的松緊程度所決定,而這又取決于能階之間的電磁力強(qiáng)度,因此便和精細(xì)結(jié)構(gòu)常數(shù)關(guān)系密切。
These findings complement recent contentious observations that the fine - structure constant , which describes the overall strength of the electromagnetic force , has increased slightly 這項發(fā)現(xiàn)為近來一項引人爭議的觀察做了補(bǔ)充:用來描述電磁力總體強(qiáng)度的精細(xì)結(jié)構(gòu)常數(shù),已經(jīng)些微增加了。詳情請見4月21日的《物理評論通訊》 。
The fine - structure constant is an important zero dimension constant in the atomic physics . this article introduces the origin of fine - structure constant , and discusses its physical significance , and theoretical calculation 摘要本文介紹原子物理學(xué)中重要的無量綱常數(shù)之一的精細(xì)結(jié)構(gòu)常數(shù)的由來,討論它的物理意義和理論計算。
And we also make the simulation of space - to - ground optical propagation by using the software of matlab , including scintillation , turbulent structure constant of atmosphere and spot of horizontal optical propagation 并用matlab語言實現(xiàn)了對空-地激光傳輸?shù)墓夤β书W爍、大氣結(jié)構(gòu)常數(shù)以及湍流大氣中的水平激光傳輸遠(yuǎn)場光斑的計算機(jī)模擬仿真。
An atmosphere structure constant cn2 model , which varies with height , is presented based on itu - r amplitude scintillation model , existing itu - r optical cn2 model and meteorologic measurement relative humidity and temperature profile data , at 10 ~ 30ghz . the log - amplitude scintillation deviation calculated in terms of the cn2 model based on humidity and temperature vertical profile compare with values predicted by means of itu - r and ortgies model . it is emerged that the calculation results based on the cn2 model agree almost with prediction results by itu - r and ortgies model at 10 ~ 30ghz and there is an advantage that relative humidity and temperature varied with height has be considered in the cn2 model 根據(jù)光波段的itu - rc _ n ~ 2模型, itu - r幅度閃爍標(biāo)準(zhǔn)偏差模型,和溫度和相對濕度隨高度變化的氣象數(shù)據(jù),在10 30ghz ,分析得到了大氣結(jié)構(gòu)常數(shù)c _ n ~ 2隨高度變化的模型;并根據(jù)溫度和濕度垂直分布數(shù)據(jù)計算了對數(shù)幅度閃爍_ x ,還與itu - r和ortgies模型的預(yù)測結(jié)果進(jìn)行了比較,結(jié)果表明,在10 30ghz ,用該c _ n ~ 2模型計算的結(jié)果和用itu - r及ortgies模型預(yù)測的值符合較好,且在用c _ n ~ 2模型計算時考慮了溫度和相對濕度隨高度變化關(guān)系。
Under our task experimental condition , we calculated the sensitivity of our planning to develop dial system with direct detection , besides , we studied the relationship between the sensitivity of measurement and atmospheric refractive - index structure constant and applied matlab program simulated the system parameters such as beam diameter , laser divergence angle , detection distance and gained relevant relationship curves 在課題實驗條件下,模擬計算了直接檢測dial系統(tǒng)的測量靈敏度。在考慮大氣折射率結(jié)構(gòu)常數(shù)對系統(tǒng)測量靈敏度影響的基礎(chǔ)上,并對各種系統(tǒng)參數(shù)如光束半徑、束散角和探測距離對測量靈敏度的影響運(yùn)用matlab程序做了仿真計算,為合理選擇系統(tǒng)設(shè)計參數(shù)提供了依據(jù)。
Since the effects of turbulent atmosphere is prominent , this thesis concentrates on the effects of the turbulent atmosphere on the laser beam propagation in the atmosphere . the atmosphere refractive index model , especially refractive index fluctuation , power spectrum , phase spatial structure constant are introduced in the following and the specific structure function is achieved 根據(jù)大氣折射率模型,以及折射率起伏功率譜密度和相位空間結(jié)構(gòu)常數(shù),得到具體的結(jié)構(gòu)函數(shù);通過長程情況下的馬爾科夫近似,得到了互相關(guān)函數(shù),對數(shù)振幅和相位協(xié)方差函數(shù)。
We have the following results through simulation and experiments : i ) turbulent structure constant of atmosphere decreases with altitude ; ii ) turbulence induced power scintillation decreases with the optical wavelength ; iii ) scintillation of space - to - ground optical propagation is smaller than that of horizontal optical propagation ; iv ) power scintillation of space - to - ground optical propagation increases with wavelength ; results above are accord with existent theory . what ' s more , the last result discovers a new rule 通過對數(shù)學(xué)模型和仿真結(jié)果的分析,得到以下結(jié)論: a )大氣湍流結(jié)構(gòu)常數(shù)隨海拔高度的增加而迅速減??; b )由湍流引起的光功率閃爍與波長呈反比; c )空-地激光通信的光功率閃爍小于地面水平傳輸?shù)拈W爍; d )空-地激光通信的光功率閃爍與波長呈正比;上述結(jié)果與理論保持一致。
According to the theory of optical wave propagation in the slant path and the itu - r turbulence structure constant model , which is altitude dependent and proposed in 2001 , the modified rytov method is extended to be applied to study on the problems , which waves propagate in the slant path . the scintillation index as a function of the rytov variance is obtained from weak to strong fluctuation regions with plane wave and sphere wave incidence , respectively 根據(jù)斜程傳輸理論和2001年提出的itu - r湍流大氣結(jié)構(gòu)常數(shù)模型,將修正pytov方法推廣應(yīng)用于斜程傳輸問題研究,得到了平面波和球面波斜程傳輸時的閃爍指數(shù),分析了湍流內(nèi)尺度、近地面風(fēng)速等參量對閃爍指數(shù)的影響。