lower beam 中文意思是什麼

Its principle is : a laminated structure ( beam or plate ) with delamination consists of undelaminated region and delaminted region which can be divided to upper and lower parts. when a low - amplitude and high - frequency excitation has the frequency close to some part ' s natural frequency, this part will resonate and certain amount of mechanical energy will convert to heat so that the delaminated region ' s temperature exceeds greatly that of the undelaminated region. therefore the delamination can be located by means of infrared thermograph

其原理是具有脫層的層合材料構件（梁或板）包含脫層區域及未脫層區域，脫層區域分為上下兩部分，若對層合材料構件施加小振幅、高頻率的振動激勵，當激勵頻率恰好接近其中一部分的固有頻率時，該部分就會產生共振響應，部分機械能將轉化為熱能，使脫層區域的溫度遠高於未脫層區域，藉助紅外熱像儀即可顯示出脫層的位置。

Elastic theory and plastic theory are adopted in the analysis of the two section composite beam. elastic theory suggests, on the condition of the same steel beam section size, the composite beam for the floorslab is suited lower flanges convertion section stiffness cuts down by 75. 1 %, elastic limit bending resistant capability cuts down by 47. 9 %, than the composite beam for the floorslab is suited on the top flange. it s conversion section stiffness is lifted 8. 0 %, elastic limit bending resistant capability is lifted 0. 20 %, than the steel beam

彈性理論分析的結果表明，在鋼梁截面大小相同的條件下，樓板位於鋼梁下翼緣的組合梁和樓板位於鋼樑上翼緣的組合梁相比，其換算截面剛度降低75 . 1 ，梁的彈性極限抗彎承載力降低47 . 9 ，樓板位於鋼梁下翼緣的組合梁和純鋼梁相比，其換算截面剛度提高8 . 0 ，梁的彈性極限抗彎承載力提高0 . 2 。

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 。

Especially in high power laser applications, absorption can cause thermal distortion to optical components, then change the transmission characteristics of the incident beam, and also lower the laser induced damage thresholds ( lidt )

尤其在高功率激光作用下，吸收損耗不僅會引起光學薄膜元件的熱畸變，影響激光傳輸特性，還會降低薄膜的損傷閾值。

The conclusion of reappearing analysis is that crane bridge be used as usual because main weld maximum stress of upper cover plate of main beam lower than yield limit though it higher than permissible stress. inner stress of secondary beam was over ultimate strength, and deforming is ultra big. so it was unfit for produce and secondary beam must be changed

再現分析得出的主要結論為：橋架的主樑上蓋板主焊縫的最大應力超過了許用應力，但小於屈服極限，可以繼續投入使用；副梁內部的應力遠遠超過了強度極限，變形特別嚴重，不能滿足生產要求，因此更換新的副梁；端梁內部的應力超過了屈服極限，小於強度極限，在應力較大的位置焊接補強板；投入使用后，要對整個橋架進行定期檢查。

Plastic theory suggests, the composite beam for the floorslab is suited lower flange, it s plastic limit moment cuts down by 52. 4 % than the composite beam for the floorslab is suited on the top flange. it s plastic limit moment lifts 8. 8 % than the steel beam, which is on the same condition

塑性理論分析的結果表明，樓板位於鋼梁下翼緣形式的組合梁和樓板位於鋼樑上翼緣形式的組合梁截面相比較，其塑性極限彎矩降低52 . 4 ，和同等條件下純鋼梁截面相比較，樓板位於鋼梁下翼緣的組合梁塑性極限彎矩提高8 . 8 。

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

Mainly its disadvantage is that the back - scattering beam is very weak, that the signal - to - noise ratio is lower

但該技術存在一些不足之處，主要是背散射信號微弱，檢測困難。

The fluctuation of ion beam has been controlled within 20 %, significantly lower than that of 50 - 80 % for external - magnetic field mid of annular configuration and ion diode without magnetic field by using polymer anodes

離子束密度的波動不超過20 ，顯著低於同類陽極的無磁絕緣和環型結構外磁絕緣離子二極體的50 - 80 。

The approach of the anchoring length of the beam ' s lower longithdinal reinforaing steel bars in the reinforced concrete frame nodes undler earthqnake loads

在地震作用下鋼筋砼框架節點梁下縱筋錨固長度探討

The damage and the decrement of light transmittance of ion exchange strengthened cover glass arc much lower than that of as - received one after ion beam bombardment, which demonstrates that ion exchanged solar cell cover glass has better resistance to ion beam bombardment

結果表明，經離子交換增強后的蓋片玻璃，彎曲強度最大可以提高約4倍；且在受到離子束轟擊時的損傷以及透光率下降的程度都小於原片玻璃，說明化學鋼化玻璃具有較好的耐離子束轟擊的能力。

After studying the computation of the adaptive beam - forming algorithms, a modified method with lower computational complexity is put forward. the research tool of the software matlab is used to validate the feasibility of the above related algorithms

本文主要的研究手段為採用科學和工程計算語言matlab進行模擬實驗，模擬各類智能天線方法的可行性，得出研究的結論。

Relativistic back wave oscillator ( rbwo ) with a coaxial structure has a big power capacity of system. with large radius electron beam to decrease the space charge effects without usage of high current, hence the rbwo can work well at a lower axial guide magnetic field

同軸返波管具有很大的功率容量，可以採用大半徑電子注，在工作電流不變的情況下空間電荷效應大幅度降低，因而可工作在低磁場狀態。

Firstly the method of rayleigh - ritz and galerkin were adopted to analyze the beams under loading combined antisymmetric end moments with transverse uniformly distributed load theoretically, and the results were compared with that offered by kirby, p. a and nethercot, d. a, it showed that result was approximate and even lower and so to some extent the approach used in the paper is practice. secondly several principal factors that affect the beam stability were analyzed respectively, especially the shortening effect was mentioned scarely in some literature so far. at last, the author adopted the matlab to program the finite element software to analyze numerically, the results derived from it were agreed well with it

本文分別採用了rayleigh - ritz法和galerkin法從理論上分析了反對稱端彎矩及橫向均布載共同作用下樑的等效彎矩系數，並與kirby ， p . a和nethercot ， d . a分析結果進行對比，結果表明本文採用的方法得出的等效彎矩系數與其得出結果比較，在均布荷載與端彎矩比例相差不大時基本接近或偏小，說明此方法是可行的，而當均布荷載與端彎矩比例較大時，應根據均布荷載作用進行彎矩等效方法來計算。

And we simulate the thing by different spatial frequency hartmann - shack wavefront sensor which is used in detecting the far field of laser beam, and we get the result that if magnitude of wave aberration is lower the dynamic range of sub - aperture of wavefront sensor, the more the spatial frequency of hartmann - shack wavefront sensor is, the more the accuracy of hartmann - shack wavefront sensor in detecting high frequency aberration is

並且波前像差在hartmann - shack波前傳感器子孔徑動態范圍之內，空間解析度高的hartmann - shack波前傳感器對高階像差波前探測時，其光束質量診斷精度高於空間解析度低的hartmann - shack波前傳感器的光束質量診斷精度。

Due to applying double beams, the velocity spread is lower because of smaller influence of space charge compared with single beam mig. in the interaction region this beam is easy to start oscillation and reject mode competition effectively

與單注磁控注入槍相比，雙注槍可以提供速度零散小、高束流的電子注，在互作用區更容易起振，且能更好的抑制模式競爭。

The experimental results show that the n contents in the multilayers are higher at the lower incidence ion energy and current. the n contents increase with the increasing of the substrate temperature. the n contents in the films also arose by using the assisted ion beam

實驗結果表明：入射離子能量較低、束流較低時，制得薄膜的n含量較高；升高溫度能增加薄膜中的n含量；輔助離子束的使用同樣增加了薄膜中的n含量；獲得的cn _ x tin _ y薄膜的最高含n量為49 . 52at 。

The natural frequencies of the intelligent beam with the rotary inertia and shear deformation of the beam are lower than that without those

考慮梁的轉動慣量和剪切變形時，智能階梯梁的頻率比沒有考慮時的要低。

At present, crack phenomenon always appears in long span prestressed concrete continuous beam bridges used, the reason of which is that the structure prestressed loss is estimated lower

目前，在部分已建成運營的大跨度預應力混凝土連續梁橋的不同部位出現了不同程度的開裂現象，多數是由於施工時對結構預應力損失估計不足所造成的。

The design realm in the province of jilin, use more software is the bridge doctor system, bridge master, system of asbest, procedure of qjx and province highway of jilins survey to design the hospital to by oneself develop of the t beam plank beam painting procedure, the cover beam calculation painting procedure, a pillar calculation procedure, the upper part procedure compute a procedure mostly, even some procedures can paint, but the province painting of basic and dissatisfied foot jilin of born diagram paper style, the diagram paper the modification quantity compare greatly, the procedure that the lower part procedure adopts to by oneself

在吉林省內設計領域，使用較多的軟體是橋梁博士系統、橋梁大師、 asbest系統、 qjx程序及吉林省公路勘測設計院自行研發的t梁板梁繪圖程序，蓋梁計算繪圖程序，樁柱計算程序，上部程序多是計算型程序，即使有些程序能夠繪圖，但生成圖紙基本不滿足吉林省繪圖風格，圖紙修改量較大，下部程序多採用自行編制的程序，但大多數程序是dos系統的程序，使用不方便，同時與現行規范多有不符。