于振文 的英文怎麼說

Abstract : considering the second nearest - neighbor interaction and cubic, quartic anharmonic interactions simultaneously, we employ the multiple scales method combined with a quasidiscreteness approximation to calculate the lattice vibration. it is shown that the kind of nonlinear chain exhibits envelope soliton, envelope kink and envelope antikink soliton. these results can also be used to explain the experimental phenomena that the kink amplitude of the self - localized structure is determined only by the intrinsic properties of its lattices

文摘:同時考慮次近鄰諧振相互作用和三次方、四次方非諧相互作用，利用多重尺度結合準離散近似方法去計算晶格振動行為，發現一維非線性點陣中存在包絡孤子及正扭結型包絡孤子、反扭結型包絡孤子，解釋了自局域結構的幅度只取決于點陣中的固有參數的實驗現象

By the large quantity of indoor and field soil mechanics test, this paper investigated physics and mechanics property of xigeda stratum and xigeda compounding filling, profoundly and systematically studied on shearing strength, cbr ( including indoor cbr and field cbr ) and intensity feature of xigeda compounding filling. the new achievement and cognition as follows : ( 1 ) cbr value is decided by moisture content and mudstone content of xigeda compounding filling. the filling material can satisfy minimum intensity standard of express highway when mudstone content is less than some fixed value, ( 2 ) this paper established field cbr standard value which can synthetically evaluate the filling material nature and field compaction degree. ( 3 ) the optimal compacting mean of xigeda compounding filling is hard oscillation first and weak oscillation later, not traditional way which is weak oscillation first and hard oscillation later. ( 4 ) this paper put forward the conception of optimum moisture content in construction different from optimum moisture content of indoor impaction

本文以昔格達填料強度特徵為研究對象，通過大量的室內及現場試驗，從昔格達地層巖組的物理力學性質、昔格達填料的物理性質入手，對昔格達填料的抗剪強度、室內承載比及現場承載比特徵進行了較系統地研究，獲得了如下認識及進展：昔格達混合填料承載比值受填料含水量及其中泥巖含量的影響，當泥巖含量小於一定值時，昔格達混合填料具有較高的承載比值，能夠滿足高速公路對填料的最低強度要求；建立了綜合評判昔格達填料性能及現場壓實效果的現場承載比（ cbr ）標準；對于昔格達填料而言，最佳的碾壓方式為先強振后弱振而不是傳統的先弱振后強振；提出了與室內擊實最優含水量相區別的施工最佳含水量的概念。

Recent study of the kilohertz quasi - periodic oscillations ( qpos ) in low mass x - ray binaries ( lmxbs ) indicates that the radiation force, other than the magnetosphere and disk interaction and the general relativity ( gr ) effect setting the inner disk edge, serves as the disk truncation mechanism on shorter time scales. some results and discussions are presented in this paper

最近對低質量x射線雙星中的千赫茲準周期振動的研究表明，是輻射壓力，而不是盤和磁球的相互作用以及處于盤內邊界的廣義相對論效應在短時標的盤切斷機制上起作用.本文給出了一些研究結果及討論

In this thesis, mainly by fmr, combined with moke and magnetic measurement, systematical studies have been made on the magnetic properties, especially magnetic anisotropy in epitaxial single crystalline fe ultathin films on gaas and inas substrates in polycrystalline thin films and in polycrystalline nife and nifeco patterned films of micron and submicron rectangular elements arrays

本論文以鐵磁共振為主要研究手段，輔助以磁性和磁光測量，對外延于gaas及inas上的不同厚度的單晶fe超薄膜、不同厚度的nife多晶薄膜和電子束光刻的多晶nife和nifeco單層利三明治結構的微米及亞微米矩形單元陣列圖形薄膜的磁性，特別是磁各向異性進行了較為系統的研究。

Abstract : a conclusion has been proved indelail that only if the na tural frequency k of a symmetric structure is nota duplicate root, the vibra tion mode of the strusture must be symmetrical orantisymmetrical. this conclusio n is advantageous to simplify the structural dynamicanalysis and pratically usef ul

文摘:給出了有關對稱結構體系的動力特性的一個結論：對稱的結構振動體系，對應于任一非重根的自振頻率，其主振型必定是對稱的或反對稱的.並給出了詳細的證明.應用這個結論，有利於對稱結構動力分析的簡化，具有實用價值

In the dissertation, the effects of the air slide - film damping on the capacitive accelerometers having different slot structures which are completely or partly etched, and fabricated by the anodic bonding between silicon and glass and bulk silicon micromachining process are researched by changing the distance between the moving structure and substrate, the thickness of the structure, the width of the completely etched slot structure, the depth of the partly etched slot structure according to the two well known air slide - film damping models

對于橫向運動的體微機械器件，其周圍空氣表現為滑膜阻尼。本文基於滑膜阻尼的兩個模型，通過改變振子與襯底的間距、振子的厚度、刻透的柵槽的寬度、沒有刻透的柵槽的深度等參數，研究了這些參數對硅?玻璃鍵合工藝製作的體硅微機械電容式傳感器阻尼特性的影響。

Study on the characteristic of piezoceramic actuator is an important step in the studying of undamaged - inspection process based on piezoceramic actuator technology. this thesis firstly dwells on the sample model of piezoceramic actuator under the restriction of concrete. through theory and experimentation analysis, we arrives at a conclusion that the vibration behavior of piezoceramic actuator belongs to that of the thin plate

本文著重研究了在混凝土約束條件下壓電陶瓷片的樣本模型，在此基礎上通過理論探討和實驗現象分析，認為埋置於混凝土中的壓電陶瓷片是符合彈性力學中克希霍夫有關薄板理論的假設，是屬于薄板振動問題，並確定了其邊界約束條件。

Firstly. operation principle of induction heating is introduced and the actuality of the power supply for induction heating is summarized. then, the scheme of structure of the power supply is established : uncontrolled rectifier and buck chopper constitute dc circuit. in this part, operation principle of a kind of soft switching buck chopper is presented mainly and the conclusion that the power semiconductor devices operate in soft switching is also illustrated by analysing the operation principle of all stages ; series resonant inverter is selected as inverter circuit via comparing the advantage and shortcoming of parallel resonant and series resonant. moreover. the work principle of series resonant inverter is analysed and the calculating method of the best dead time is put forward as well

文中首先介紹了感應加熱電源的工作原理並綜述了國內外的研究現狀。接下來分析並制定了電源主電路的構成方案：在對比幾種功率調節方式的基礎上選擇了不控整流加斬波調壓作為直流部分。在這部分里，重點研究了一種軟開關buck變換器，通過分析各階段的工作原理說明了開關器件如何工作在軟開關狀態；對于逆變器部分，在比較了串、並聯逆變器優缺點的基礎上選擇了串聯諧振逆變器，並詳細分析了串聯逆變器的工作原理，提出了最佳死區的計算方法。

As to the current problems existing in the identification for these flutter derivatives, the dissertation tries to trace the development in the identification for the past unsteady aerodynamic forces of long - span bridges. it also investigates the method for flutter and buffeting analysis and the flutter derivatives. based on the present methods used in obtaining the unsteady aerodynamic forces and flutter derivatives, and co - funded by a natural scientific fund from the nation and a key project fund from the railway ministry, the current research has attempted to develop a device which can be employed in the wind tunnel to test flutter derivative through a forced vibration method

鑒于目前橋梁斷面顫振導數識別的水平和存在的問題，本文通過對大跨度橋梁非定常氣動力、顫振分析方法及顫振導數識別方法的回顧和評述，基於現有的非定常氣動力和顫振導數的測試方法，在國家自然科學基金與鐵道部重點學科基金的聯合資助下，研究開發了一套在風洞中採用強迫振動法測試顫振導數的裝置。

Abstract : we have studied the spontaneous emission from a three - level atom with an external - driving field in a photonic crystal. as a result of quantum interference and photon localization, the population in the two upper levels displays quasi - oscillatory oroscillatory behavior. this depends on the initial atomic state and the relative positions of the two upper levels from the forbidden gap. the intensity and the phase of the external field can affect spontaneous emission from the atom. the properties are different from a three - level atom either in vacuum or in aphotonic crystal without an external driving field

文摘:討論了在雙光子驅動場作用下，三能級原子在光子晶體中的自發發射問題.由於量子干涉和光的局域化作用，兩個上能級中的占據數將具有周期振蕩或準周期振蕩的性質，這不僅依賴于兩個上能級與禁帶的相對位置，同時也依賴于原子的初始狀態，而且還與驅動場的強度、驅動場的入射位相有關.這些性質既與真空中帶有驅動場的原子的自發發射性質不同，也有別于無驅動場作用下光子晶體中三能級原子的自發發射性質

According to the guidline, two nd : yag lasers have been designed and set up, one is end - pumped by lower output power ld using a selfoc micro lens, and the other is end - pumped by high output power ld using a pair of lenses are designed, and the characteristics such as output power and power stabilization of both solid - state lasers are investigated. thirdly, when an empty liquid crystal cell is inserted in the cavity of the nd : yag laser pumped by high power ld, the laser can operates in single axial mode. finally, according to the relationship between the laser output power and the longnitudinal a ld - end - pumped nd : yag laser sensor for displacement measurement has been investigated theoretically and demonstrated experimently, the results indicate that when the mean radius of pumping inside the laser cavity is far less than that of the oscilating laser mode, the exponential of the output power is a gauss function of the longitudinal positon of focused spot of ld pumping beam, both the measurement range and the sensitivity are dependent on the incident pumping power, as the incident pumping power is increased, the measurement range is enlarged and the sensitivity is improve d

本文首先介紹了ld泵浦nd ： yag激光器的發展狀況、主要特性及其應用，從四能級速率方程出發，推導了ld泵浦nd ： yag激光器的閾值、輸出功率和斜效率的表達式，並簡述了激光器的工作原理、結構型式和倍頻方法；其次，以空間相關的速率方程為基礎，提出了ld端面泵浦nd ： yag激光器的設計方法，給出了一定泵浦耦合方式下，振蕩光模尺寸、最佳輸出耦合率、泵浦光模尺寸、泵浦光焦斑位置等參數的選取依據，以此為依據，設計了自聚焦透鏡耦合小功率ld泵浦nd ： yag激光器和透鏡組耦合高功率ld泵浦nd ： yag激光器，對激光器的輸出功率和功率穩定性等特性進行了實驗研究；再次，在帶尾纖輸出的高功率ld泵浦nd ： yag激光腔內插入一隻空液晶盒，觀察到了激光器以單縱模運轉；最後，根據泵浦光焦斑端面位置對激光輸出功率的影響規律，提出了ld端面泵浦nd ： yag激光位移傳感新方法，並進行了理論和實驗研究，研究結果表明：當激光晶體內泵浦光平均光斑半徑遠小於振西安理工大學碩士學位論文蕩光束腰半徑時，激光輸出功率的自然指數與泵浦光焦斑的縱向位置成高斯變化規律，測量范圍和靈敏度依賴于泵浦功率，隨著泵浦功率的增加，測量范圍擴大，靈敏度提高，當端面泵浦功率為7 . 24w （最大輸出功率為1 . 926w ）時，激光位移傳感器的測量范圍和靈敏度分別是13 . 045mm和0 . 148mw / pm 。

Based on the advanced embedded computer and network technology along with the embedded operational system such as windowsce, the instruments can gather many functions such as transmitting and measurement, compensatory computation, signal analysis and processing into one instrument. in this paper a portable instrument for vibration measurement with embedded computer system was discussed. based on windowsce real - time operation system the software of this instrument was designed and developed with evc computer language

本文基於目前流行的便攜式儀器的核心技術? ? windowsce ，設計開發了應用於現場設備振動測量分析的的便攜式測振儀表，針對現場特點和實際要求，對于測振儀的硬體系統進行了規劃設計，並重點對于儀器軟體進行開發，在windowsce平臺下，利用evc語言開發研製了儀器的應用軟體，實現了包括信號採集、分析、顯示、數據存儲和通信功能的軟體系統；並對該軟體進行了計算機模擬調試。

To meet this challenge, a research project was supported by ministry of communication and bv shanghai zhenhua port machinery co. ltd. focusing on analysis of tdtcd ( traditional design theories of crane drums ) the paper has studied the impacts of features under the binding force of wire ropes, the end - plate and rope slot. this study is based not only on the thin shell theory and viscoelastic mechanics to calculate the strength and stability of drum, but also on an experiment with technology in " state of act "

本文結合交通部重點科技項目「港口起重機鋼絲繩傳動件高性能技術研究」和上海振華港機股份有限公司委託項目「起重機焊接捲筒極限壁厚研究」 ，針對起重機捲筒傳統設計方法偏於保守的情況，以薄殼理論和近代力學為基礎，以現代試驗技術為研究手段，對鋼絲繩緊箍力作用下的外載特性、端板、繩槽等因素對捲筒強度和穩定性的影響進行了系統的理論研究，在深入開展捲筒強度、穩定性和實驗模態分析等試驗的基礎上，提出了有別于傳統方法的捲筒強度、穩定性計算方法。

After a series of reactions, an ester which is a derivative of ferrocene is obtained, then using the ester react with 1, 8 - naphthalenediamme, o - m -, p - phenyleiiediamine, ethylenediamine and 4. 4 ' - - biphenyldiamine respectively, polymer ( i ) ( ii ) ( iii ) ( iv ) ( v ) and polymer ( vi ) are obtained at the final part, we have discussed in brief the general properties of polymer ( i ) - { vi ) and analyzed systematically hnmr ir spectrum tg - dt diagram and molecular weight distribution of these polymers

簡要討論了聚合物（ i ）一（ vi ）的一般性質，對聚合物的核磁共振譜、紅外光譜、 t （卜刃t圖以及分子量分佈進行了系統研究。本文對聚合物（ i ） 、 （ 111 ）和（硯）的核磁共振譜和紅外光譜進行了分析，研究結果表明:聚合物中的援基上的氧原子能與芳胺上的氫原子形成分子內氫鍵，使聚合物的分子內出現了一個平面六元環結構，並山于分子內氫鍵的存在

The characteristics of precipitation anomalies in summer, previous and simultaneous ssta and preceding winter accumulated snow depth anomalies corresponding to positive and negative phases of 10 - yr mode and 25 - 30 - yr mode are discussed respectively. no matter for 10 - yr mode or for 25 - 30 - yr mode, reverse characteristics corresponding to positive phases and negative phases appear in the above fields. it proves that the decadal variation of sah have a good relation to the decadal variation of other key element of climate system and we can regard sah as a strong signal of the anomalies in the climate system

（ 4 ）夏季南亞高壓東西振蕩具有明顯的年代際變化特徵，本文分別討論了對應於10年周期態的正位相年和負位相年及25 - 30年周期態的正位相年和負位相年時夏季我國降水距平、前期及同期海溫距平及前冬青藏高原積雪距平的分佈特徵，發現無論是10年周期態還是25 - 30年周期態，對于夏季南亞高壓東西振蕩的正位相年和負位相年以上各要素場呈現為很好的反位相特徵，說明夏季南亞高壓的年代際變化與氣候系統中其他要素的年代際變化具有很好的關聯性，可將南亞高壓看作氣候系統中大氣子系統異常的強信號，通過分析南亞高壓的年代際異常可以更直接地研究和預測區域氣候異常。

The ultra - thin er layers with the thicanesses in the range of 0. 5 ~ 3 monolayer ( ml ) are formed by electron beam evaporation on si ( 00l ) substrate at room temperature in an ultra - high vacuum system. after annealing at lower temperatures, ordered simcfores form on the surface. the trallsition of the surface reconsmiction pattem from ( 2 x l ) to ( 4 x 2 ) with the increase of er coverage up to l ml is observed by the reflective high energy electron diffraction ( rheed ) and low energy electron diffraction ( leed )

本文是關于硅（ 001 ）襯底與電子束淀積的鉺、鉿原子反應形成的超薄膜的界面與表面性質的研究，以及在該襯底上出現的共振光電子發射現象，包括了以下四個方面的工作： 1鉺導致的硅（ 001 ）襯底上的（ 4 2 ）再構研究利用反射高能電子衍射和低能電子衍射，在室溫淀積了0

In this paper, a new control strategy based on the adaptive deadbeat voltage space vector is presented. this control scheme has a lower sample frequency and a smaller difference between switch frequency and sample frequency. it has many advantages, such as producing zero vectors organically, tracing exactly, non - shaking, etc. and its dynamic response is better

對于電能質量調節器來講， pwm跟隨指令參考信號的控制性能在很大程度上影響著裝置的補償效果，本文選擇無差拍電壓空間矢量控制為系統控制策略，這種控制方法具有采樣頻率低，開關頻率與采樣頻率的差距小，能有機地產主零矢量、跟蹤精確以及無抖振等優點，動態響應快。

Conditions of normal mode realization are deduced and optimized model with the multivariate mode indicator function as the target function is built. through solving the maximal eigenvalue problem, the original shaker force vector of appropriation is reached. then the realization approach of the optimal shaker force vector based on single shape principle is proposed and at the same time the automatization of normal mode appropriation is realized

對于模態物理分離技術的多點正弦激振純模態試驗技術，尋求其最佳激振力矢量是最為關鍵的環節，本文先推導出純模態實現的條件，建立以多變量模態指示函數為目標函數的優化模型，通過求解最大特徵值問題，得出適調純模態的初始激振力矢量，再提出以單純形原理為基礎的最佳激振力矢量的實現方法，同時也實現了純模態適調過程的自動化。

The conventional variable structure control technique for uncertain system requires that the uncertainty bound is known as a premise to assure robustness. the requirement creates an over - conservative controller and enlarges chattering. the proposed controller regards the influence of unknown disturbances and parameter uncertainties as an equivalent disturbance and generates an on - line estimation used in smc to cancel the slowly varying uncertainties by the mechanism of time delay. the reaching law approach is used to get the conditions and band of quasi - sliding mode. the new methodology offers a robust feedback control with much lower gains and reduces chattering without a prior knowledge of the uncertainty bounds or matched conditions

常規變結構控制用於不確定系統，須利用不確定性界確保系統的魯棒性，控制器過于保守且抖振變大.本文把未知干擾和參數不確定性的影響等效為名義系統的外界干擾，利用時延技術對干擾進行在線估計，並將估計值引入到變結構控制中，從而抵消掉系統中的慢變不確定性，利用離散趨近律法，推出了準滑動模態的存在條件及其帶寬.該方法克服了以往控制方法中須已知不確定性界的限制，且不必滿足匹配條件，用較低的控制增益保證了系統的魯棒性，降低了準滑動模態帶即削弱了抖振

Abstract : the conventional variable structure control technique for uncertain system requires that the uncertainty bound is known as a premise to assure robustness. the requirement creates an over - conservative controller and enlarges chattering. the proposed controller regards the influence of unknown disturbances and parameter uncertainties as an equivalent disturbance and generates an on - line estimation used in smc to cancel the slowly varying uncertainties by the mechanism of time delay. the reaching law approach is used to get the conditions and band of quasi - sliding mode. the new methodology offers a robust feedback control with much lower gains and reduces chattering without a prior knowledge of the uncertainty bounds or matched conditions

文摘:常規變結構控制用於不確定系統，須利用不確定性界確保系統的魯棒性，控制器過于保守且抖振變大.本文把未知干擾和參數不確定性的影響等效為名義系統的外界干擾，利用時延技術對干擾進行在線估計，並將估計值引入到變結構控制中，從而抵消掉系統中的慢變不確定性，利用離散趨近律法，推出了準滑動模態的存在條件及其帶寬.該方法克服了以往控制方法中須已知不確定性界的限制，且不必滿足匹配條件，用較低的控制增益保證了系統的魯棒性，降低了準滑動模態帶即削弱了抖振