星系演化 的英文怎麼說
中文拼音 [xīngxìyǎnhuà]
星系演化
英文
galaxy formation and evolution-
Far from an austere backwater, the intergalactic medium ( igm ) is turning out to be the central staging area for cosmic evolution
星系際介質( igm )完全不是死水一潭,它正躍居宇宙演化的中心舞臺。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。Our galaxy is a continuously evolving system.
我們的星系是一個不斷演化的星系。Abstract : based on the synthetical data from the remote images, geological section, geomorphologic landscape, ancient water system evolution and surface feature spectrum etc, the study indicates that there is an undersand lake in the northern peripberal belt of qarhan salt lakes of qaidam basin
文摘:根據地球衛星遙感影象、地物波譜測定以及地貌景觀、古水系演化和地面地質調查等資料的綜合研究表明,柴達木盆地察爾汗鹽湖礦區北部外圍地帶存在一種新的成因類型的鹽湖? ?沙下鹽湖。On the bases of the galaxy evolution theory, we use the therotical chemical evolution model of three zone ( such as halo, thick disk and thin isk ) and multi - phase ( diffuse gas, molecular clouds, stars of both low and high mass, the remnants ). by comparing with the observational constraints, such assurface densities, age - metallicity relation, g - dwarf metallicity distribution in the solar neighbourhood and the correlation between [ a / fe ] and [ fe / h ], supernovae rates, infall rates. the rationality of the model is verified. based on the theory model, we calculate the abundance of neutron capture element
本文正是在銀河系化學演化的基礎上,利用銀河系的三成分( threezone ) (即暈、厚盤和薄盤)多相( multi - phase ) (氣體,分子云,大、小質量恆星以及剩餘物質)的化學演化的理論模型,通過與觀測約束(質量面密度、場星的年齡-金屬豐度關系、太陽附近g矮星金屬含量分佈函數、三成份的特徵量、元素的星系化學演化、超新星的爆炸率、內落速率等)的比較,來檢驗模型的合理性。This thesis studies the tidal creek system on the prograding mud flat in jiangsu province based on 16 pieces of mss, tm and spot images from 1973 to 2001, and analyses the growth, genetic classification, evolution and affecting factors of tidal creeks
本文結合1973年至2001年共16張不同時相的衛星影像對江蘇淤長型淤泥質潮灘上的潮溝系統進行了研究,對潮溝的發育、形成、演化和影響因素進行了初步探討。In general, ba stars belong to binary system, and their heavy - element overabundances are due to the accreting material from the companions ( the former tp - agb stars and the present white dwarfs ). carrying out a series of monte - carlo simulations, the changes of orbital elements of binaries are recalculated for wind accretion scenario of the total angular momentum conservation
研究表明,鋇星應該屬于雙星系統,其重元素超豐來自雙星吸積,它的伴星已經經歷了s -過程核合成,而且由在以前發生的同其伴星(以前是agb星,現已演化為白矮星)的質量傳輸過程中,從伴星那裡獲得了富含重元素的物質,這樣造成了鋇星的重元素超豐。The asteroids are the most important small bodies in the solarsystem, and they mainly lies in the two locations - a main belt between the mars ' s orbit and the jupiter ' s and the near - earth space. the most feature of the orbits of near - earth asteroids ( neas ) is that the semi - major axes of the orbits are nearly equal to that of the earth or the perihelia distances are approximate to or even less than the mean distance between the sun and the earth, thus they could move into inside of the earth ' s orbit, so that they might close approach or even colliside with the earth ( or other planets, such as the venus, the mars, etc. ). the characteristic brings about some difficulties in the numerical research during their orbital evolution, which leads to the failure of the normalization technique in the general removal impact singularities of celestial mechanics methods and the symplectic algorithm which is successfully applied to the investigation in quality. by comparing the computation effects of several common numerical methods ( including symplectic algorithm ), and considering the nature of the movement of the small bodies, the corresponding treatments are provided here to improve the reliability of the computation
小行星是太陽系最重要的一類小天體,主要分佈在兩個區域;火星和木星軌道之間的一條主帶和近地空間.近地小行星軌道的最大特點是其軌道半長徑與地球軌道半長徑相近,或近日距離接近甚至小於日地平均距離,其運動可深入到地球軌道的內部,這將導致該類小行星與地球(還有金星、火星等)十分靠近甚至發生碰撞.這一特徵給其軌道演化數值研究帶來一些困難,包括天體力學方法中一般消除碰撞奇點的正規化處理以及對定性研究十分成功的辛演算法都將在不同程度上失效.通過對幾種常用數值方法(包括辛演算法)計算效果的比較,根據小天體運動自身的特性,給出了相應處理措施,從而可提高計算結果的可靠性During the early stages of planetary evolution they served to sweep the solar system.
在行星演化的早期,他們用來清掃太陽系。Topics include : planets, planet formation ; stars, the sun, " normal " stars, star formation ; stellar evolution, supernovae, compact objects ( white dwarfs, neutron stars, and black holes ), plusars, binary x - ray sources ; star clusters, globular and open clusters ; interstellar medium, gas, dust, magnetic fields, cosmic rays ; distance ladder ; galaxies, normal and active galaxies, jets ; gravitational lensing ; large scaling structure ; newtonian cosmology, dynamical expansion and thermal history of the universe ; cosmic microwave background radiation ; big - bang nucleosynthesis
課程的主題包含了:行星、行星形成;恆星、太陽、正常的恆星、恆星形成;恆星演化、超新星、緻密天體(白矮星、中子星及黑洞) 、波霎、雙x -射線源;星團、球狀及疏散星團;星際介質、氣體、塵埃、磁場、宇宙射線;距離階梯;星系、正常及活躍星系、噴流;重力透鏡;大尺度結構;牛頓宇宙學、宇宙的動力膨脹及溫度發展歷史;宇宙背景微波輻射;大霹靂核合成。Another advantage, contrast to using convolutional codes or turbo codes, is its low complexity while maintain high ber performance because the check equations are used to terminate the both iterations. we develop the theoretical error free feedback bound for bpcm - id and predict the threshold for decder convergence using the extrinsic information ransfer chart ( exit )
利用非正則ldpc具有不同度的信息節點概率密度演化的差異,對高階星座中具有較高級別的子通道提供額外的保護,可使迭代反饋判決時,星座子集擁有最大的無錯反饋歐氏距離調和均值,從而改善系統的迭代收斂特性。The aim of the galaxy chemical evolution research is to reproduce the element abundance patter of stars and gas in the galaxy
銀河系化學演化研究的任務,從根本來說,是重現銀河系中恆星與氣體的元素豐度分布圖象。We calculate a model with angular momentum loss caused by gravitational radiation, and find that the binary undergo cyclic evolution as well. however, the period of the cycle becomes shorter, and the ratio of the time spent in the semi - detached phase to the time spent in the contact phase in a cycle becomes smaller
我們計算了由引力波輻射引起雙星系統的角動量損失的演化模型,發現雙星系統還是經歷循環演化,不過循環的周期變短,且雙星系統的每一個循環處在半接狀態的時間與處在相接狀態的時間之比變小。The evolution time in our calculation is chosen to be 12 gyr, which is the mean value of globular cluster ages in the galaxy
恆星蒸發對小質量球狀星團的演化起著主導作用,大質量恆星的演化、銀河系核球和盤的沖擊加熱以及動力學磨擦則主要影響大質量球狀星團的演化。Among the evolution is the chemical evolution of the galaxy showing its exceeding importance. the recognize to the galaxy chemical evolution build up the basement of understanding the whole galaxy evolution. and it can restrict and constrain the evolution and ncleosyhthesis of the stellar
其中銀河系的化學演化在其中更是具有極其重要的地位,對銀河系化學演化的認識是理解整個銀河系演化的基礎,並對恆星演化與核合成理論提供約束。They are the stellar evaporation in the tidal field, the stellar evolution during the early evolutionary stage, the tidal shocks due to clusters passing through the bulge and disk, and the dynamical friction
本文考慮的動力學過程有四種,即:恆星蒸發、早期大質量恆星的演化、銀河系核球和盤的沖擊加熱以及動力學磨擦。This image combines data from four different observatories : the chandra x - ray observatory ( purple ) ; the galaxy evolution explorer satellite ( ultraviolet / blue ) ; the hubble space telescope ( visible / green ) ; the spitzer space telescope ( infrared / red )
這張照片是使用4架軌道天文臺的數據合成的:錢德拉x射線天文臺(紫) 、星系演化探測器(紫外波段,藍色) 、哈勃太空望遠鏡(可見光波段,綠色)以及斯必澤太空望遠鏡(紅外波段,紅色) 。Our model introduces the general equations of chemical evolution used in galaxies to studies of gcs. in this model the important gas outflow caused by the supernova explosion and other processes during the formation of globular clusters is included. based on such a self - enrichment model, monte carlo method is used to simulate the formation and chemical evolution of globular cluster systems, from which a new explanation of the bimodal metallicity distribution can be given
本文把星系演化中通用的化學演化方程引入到球狀星團這一系統中來,特別考慮到球狀星團中恆星形成過程中超新星爆發等因素引發的氣體外流,把這一重要的物理過程包含到化學演化方程中,並用蒙特卡羅方法來模擬球狀星團系統的自增豐演化。They are important objects in studying stellar evolutions
這些天體都和恆星的演化有密切的關系。The dissertatation consists of two sections. the first one mainly intrduce the chemical evolution model and observational constrain, and the second mainly intrduce the ncleosyhthesis of r - process and the chemical evolution of ba peak elements the formation and evolution of the galaxy has long been a basic and important branch and one of the most active frontiers in the fields of astrophysics
本文分二部分,第一部分重點介紹星系的化學演化模型和觀測約束,第二部分重點介紹r - process核合成和ba峰元素r - process的星系化學演化。分享友人