Many planets ( for example, ganymede, mercury, the earth, jupiter and saturn ) and stars ( for example, the sun ) possess intrinsic magnetic fields. the explanation for their existence and variation remains a great challenge to planetary scientists and astrophysicists. this article attempts to review some recent developments and difficulties in the study of magnetohydrodynamics for the electrically conducting fluid interiors of planets and stars. it is the fluid motions, usually driven by thermal convection, that generate and sustain magnetic fields through magnetohydrodynamic processes in planets and stars. in planets, the magnetohydrodynamic processes are strongly affected by the combined and inseparable effects of rotation, magnetic fields and spherical geometry. the key dynamics involves the interaction between the coriolis and lorentz forces. in the sun, it is the solar tachocline, a thin shear flow layer located at the base of the convection envelope, that plays an essential role in the solar magnetohydrodynamic processes which produce the 11 - year sunspot cycle. some results of a new nonlinear three - dimensional solar dynamo model are also presented
許多行星(如木衛三,水星,地球,木星和土星)和恆星(如太陽)具有內部磁場.對這些磁場的存在和變化的解釋對行星
科學家和天體物理學家是一個巨大的挑戰.本文試圖總結行星和恆星的導電流體內部磁流體力學研究的新近發展和困難.一般由
熱對流驅動的流動通過磁流體力學過程產生並維持在行星和恆星中的磁場.在行星中磁流體力學過程強烈地受到轉動,磁場和球幾何位型的綜合影響.其動力學的關鍵方面涉及
科里奧
利力和洛倫茲力間的相互作用.在太陽中其流線,即處于對流層的薄的剪切流層在太陽的磁流體力學過程中扮演了一個基本的角色,並由之產生了11年的太陽黑子周期.本文也給出了一個新的非線性三維太陽發電機模型
He was a cold flame of a man, small as koho, and as dried up, with a mahogany complexion and small expression less blue eyes that were more like gimlet-points.
他是冷若冰霜的人,象
科霍一樣矮小干癟,皮膚呈赤褐色,一對毫無
熱情的藍色小眼睛酷似兩只銳
利的錐尖。
Scientists have come up with a mouthwatering invention which could change the lives of chocoholics in the summer - a type of chocolate that does not melt in the heat
編輯整理奈及
利亞
科學家最近發明了一種耐
熱巧克力。這種巧克力在炎
熱的夏天裡不易變軟或融化,好吃者可以隨身攜帶隨時享用。
Cactaceae ( cacti ) a large family of succulent xerophytic dicotyledonous plants, found mainly in warm dry parts of the americas ; some species, notably the prickly pears ( opuntia ), have been introduced to the mediterranean and australia
仙人掌
科:一類肉質的旱生雙子葉植物,主要分佈於美洲的炎
熱乾燥的區域,仙人掌果(仙人掌屬)被引入地中海以及澳大
利亞。
University ranking and science research evaluation has been a hot problem from 1980 ' s, and it ' s also quite a controversial domain in scientometrics and bibliometrics
大學排名和
科學定量研究是目前學術界內外都關注的
熱點和敏感問題,而文獻計量指標的合理
利用是這個問題的焦點之一。
The swertia belongs in gentianaceae. lt has about 154 species in the world, 79 species in china, about 35 species to be used for medicine, 20 species of medicinal plants can be found in sichuan and hubei provinces., which are used for medicine in dried herbs. their main functions are to clear heat, detoxify toxin, clear liver, eliminate dampness and normalize the gallbladder, for the treatment of jaundice, blood urination, hot and painful strangury etc. in the traditional medicine of india and japan, it is used as drugs bitter in taste to strengthen the stomach. the modern pharmacological studies show they have many biological activities. some drugs have been registered in the drug standards of the nation and the local government. the medicinal resources produced in sichuan and hubei provinces are abundant, which account for over half of the whole country. therefore, it is necessary to investigate the botanic origin and research the macroscopic, microscopic and chemical characteristics of them. its objective is to establish and improve the quality evaluation system in order to guide the exploitation and utilization for swertia medicinal plants
獐牙菜屬( swertia )是龍膽
科中的一個大屬,全世界約有154種,中國分佈的有79種,有藥用記載的約35種,其中川鄂產藥用種類約20種,均以全草入藥,常具有清
熱解毒,清肝除濕
利膽之功效,主要用於黃疸尿赤、
熱淋澀痛等癥;在印度和日本傳統醫學作為苦味健胃藥使用。現代藥理學研究表明具有多種藥理作用。有的品種在國家和地方藥物標準中已有收載。
Socialist party of croatia ( spc ) : zagreb ; pres. - zeljko mazar
克羅埃西亞社會黨:薩格勒布;主席
熱利科?馬扎爾。
The second chapter studies the economy of ship ' s power plants, based on the aspects of lowering fuel cost, waste heat recovery, the match of ship, machinery and propeller, increasing propulsion efficiency, increasing the economy of ship ' s power plants, etc. the third chapter discusses in detail the control measures of voyage change cost, analysizes systematically the voyage change cost based on the way of fuel cost, harbor cost, voyage venture cost. the fourth chapter studies the structures and control measures of seafarers cost, maintenance cost, spare parts and stores cost, lubricating oil cost, etc. which are relatively easy to be controlled ; based on the state maintenance decision - making, a mathematical model is put forward, the validity and its solve process are discussed. the control measures of spare parts, fuel cost and lubricating oil cost should be based on scientific budget, through the control means of application, reception, usage, store check, try to acquire the inosculation of theory
第一章主要討論營運船舶運輸成本,對船舶運輸成本的概念、結構、性質與分攤、成本細分進行了分析,從宏觀上闡明了船舶運輸成本的生存環境和生長趨勢;第二章研究了船舶動力裝置的經濟性,在營運船舶降低油耗、廢
熱利用、船機槳匹配、提高推進效率、提高船舶動力裝置經濟性的有效途徑等方面進行了闡述和論證;第三章詳細論述並論證了航次變動成本的控制措施,全面系統地分析和總結了航次變動成本,通過對燃油成本、港口使費、航次風險成本的分析與控制,提出了航次風險成本的概念並論述了若干航次風險成本的控制措施;第四章對船舶營運成本中的船員費用控制、維修保養及其費用控制、船舶備件物料管理及其費用控制等幾個主要可控性較高的成本進行了細致的分析並分別討論了相互的控制措施,提出了基於狀態維修決策的馬爾可夫數學模型並論證了模型的正確性及具體解算步驟,對于備件、燃潤物料的控制堅持以
科學的預算為前提,以申領、接收、使用、盤存為控制環節,切實做到理論與實踐的密切結合;第五章,結合營運成本的預核算的案例,對船舶營運成本的預算及核算進行了有益的探討,旨在揭示成本發生的動因,並給出了成本預算、核算的編制方法。
Chemical history education is been in chemical teaching, promote student using chemical histoiy to utilize dialectics materialism viewpoint and historical materialism viewpoint, knowledge and analysis chemical knowledge, form and develop to train innovation ability and the scientific quality of student, raise the learning interest of student, train student to love science, love motherland, repay motherland, strengthen the noble moral of legal consciousness is the education of basic goal
化學史教育就是在化學教學中,
利用化學史來促進學生運用辯證唯物主義觀點和歷史唯物主義觀點,認識和分析化學知識的形成和發展,以培養學生的
科學素質和創新能力,提高學生的學習興趣,培養學生
熱愛
科學、
熱愛祖國、報效祖國、增強法律意識的高尚情操等為根本目標的教育。
With major doubts over ledley king and rooney, plus fears regarding michael owen and ashley cole, at least terry should be available to figure in the warm - up games after the scan showed there was no deep bruising on the bone
現在最不確定的是萊德
利?金和魯尼的傷情,而且人們也擔心邁克爾?歐文和阿什
利?
科爾的身體狀況,但至少特里的傷情是樂觀的,檢查表明他的骨頭沒有受到傷害,他能夠參加世界盃前的
熱身賽。
Ashley cole will be making his first appearance at white hart lane since his move from spurs ' hated rivals arsenal on transfer deadline day
在夏季轉會期結束的當天從
熱刺的死敵阿森納轉會到切爾西的左後衛阿什
利.
科爾將代表藍軍首次在白鹿巷球場(
熱刺主場)進行比賽。
It ' s all part of falling passionately in love - - and scientists now tell us the feeling won ' t last more than a year
但義大
利科學家現在要告訴你,這種美妙的感覺不會超過1年,也就是說你的
熱戀最多只能持續1年的時間。
It ' s all part of falling passionately in love - and scientists now tell us the feeling wo n ' t last more than a year
但義大
利科學家現在要告訴你,這種美妙的感覺不會超過1年,也就是說你的
熱戀最多只能持續1年的時間。
Since energy crisis occurred in 1970 ' s, latent heat thermal energy storage ( lhtes ) has gained more attention than before due to its being the key element to accomplish energy recovery and utilization of solar energy, industrial waste heat and off peak electricity. compared with developed countries, in this area, china still has a long way to go
自上個世紀70年代能源危機以來,相變貯能的理論與應用研究在世界發達國家迅速崛起並得到不斷發展,其研究和應用涉及材料科學、太陽能、工程熱物理、空調和採暖及工業廢熱利用等領域。