查询词典 beam-focusing

The prestressed concrete simple beam compares reinforced concrete beam to compare, the merit includes: Uses the high marking concrete, section minification, the dead weight reduces, may increase the spanning ability; Uses the high strength steel bar, may save the steel products; But raises the sorghum body large scale the crack resistance, increases beam's durability, the concrete total cross-section bearing, has fully displayed the concrete resistant to compression performance superiority, also enhanced Liang's rigidity.

预应力混凝土简支梁较钢筋混凝土梁相比，优点有：采用高标号混凝土，截面尺寸减小，梁体自重减轻，可以增大跨越能力；采用高强度的钢筋，可节约钢材；可大幅度提高梁体的抗裂性，增加梁的耐久性，混凝土全截面受压，充分发挥了混凝土抗压性能的优势，也提高了梁的刚度。

Secondly, three kinds of mathematics model of optical vortex beams were introduced here. Then the propagation dynamics of optical vortex beams through the non-axis symmetry system is studied, this chapter includes the introduction of the symmetry vortex beam and the non- symmetry vortex beam, the deduction of the Collins diffract integral formula for the non-axis symmetry system, and the transformation of the vortex beam passing through the non-axis symmetry system has been described by using the numerical simulation. Then the general calculation for the orbit momentum of vortex beams, the matrix form for the orbit momentum of vortex beams, and the photon method to describe the orbit momentum of vortex beams are also introduced here. Finally, the interference about optical vortex beams was studied.

本文对涡旋光束进行了较为全面的介绍和研究，主要内容包括：（1）光学涡旋光束的基本理论，主要是介绍了单个光学涡旋光束在柱坐标中的一些表征，涡旋光束的奇异相位和光学涡旋的相位结构；（2）光学涡旋光束的三种数学模型；（3）光学涡旋光束在非轴对称光学系统中的传播动力学，其中介绍了对称涡旋光束与非对称涡旋光束，推导了非轴对称光学系统的 Collins 衍射积分公式，并利用计算机模拟图描述了对称涡旋光束经过非轴对称光学系统后涡旋形态的改变；（4）涡旋光束轨道角动量的一般计算，涡旋光束轨道角动量的矩阵形式，光子法描述涡旋的轨道角动量；（5）涡旋光束的干涉。

In this paper, draw the idea of beam unit, the bias along the vertical box is divided into a number of oblique beam. On the basis of analysis of the displacement, through positive and oblique coordinate transformation relations, and directly built on the oblique coordinate system to describe the methods of displacement unit space. With potential energy principle is derived in oblique beam element stiffness matrix and the establishment of the finite element formulation. The preparation process of the finite element analysis is used to verify the structure of bias.

本文吸取梁段单元的思想，将斜交箱梁沿纵向划分为若干斜梁段，在位移分析的基础上，通过正、斜交坐标转换关系，直接建立在斜交坐标系内描述单元空间位移的方法，用势能驻值原理推导斜梁单元刚度矩阵并建立其有限单元列式，利用编制的有限元程序进行斜交结构的分析。

In order to use electron beam in brazing of precise structures and thermo-sensitive materials,accommodating every kinds of curve brazing seams,a vacuum electron beam brazing temperature closed loop control system was developed using PID controller,electron beam scanning track editing and on-line adjusting technologies,real-time acquisition and handling of brazing temperature.

为了将电子束应用于精密构件及热敏感性材料钎焊，以适应复杂形状曲线钎焊缝的要求，采用电子束扫描轨迹编辑及在线调节、钎焊温度实时采集及PID控制器构建真空电子束钎焊温度闭环控制系统。

When the probe rotates a circle, the picture of the beam profile in two perpendicular directions is given, the position of the beam in the beam line and its intensity are also displayed.

本截面仪采用磁耦合静密封代替旋转密封，结构简单、使用方便。

The light source directs rays through a plane convex lens that focuses the light into a parallel beam. The light beam passes through the grid diaphragm, which splits it to produce a second beam of light 90° out of phase.

光源将光线照射到平凸透镜上，透镜将光线聚焦成平行光束，光束穿过光栅膜片，光栅将光束分离出第二根90度异相光束。

Combining with the National Natural Science Foundation ofChina(No.50478032), following researches were done in this thesis: 1 The variation regularity of the ultimate anti-bending capacity of therectangular-sectioned beam with different corrosion has been obtained through thequalitative analysis of 48 beams (32 corroded beams and 12 comparing beams) withaccelerated corrosion; 2 The conclusion has been obtained that the strain of corroded steel bar andconcrete no longer fit in with the assumption of plane section through the analysis ofthe strain data, the strain relation of steel bar and concrete in the mid-span section ofvariously corroded beams at ultimate has been obtained. Through the building of newgeometric relation, the expression of the height of compressive area in the corrodedbeam with rectangular section has been deduced, and the formula with corrosion rateas the main variable for the anti-bending capacity of the corroded concrete beam hasbeen suggested and verified by experiment.; 3 The influence of steel bar corrosion and the concrete regression to the flexureductility coefficient of the corroded structure component has been analyzed. Based onthe relation of steel bar and concrete at yield and ultimate, the expression for theflexure at yield and ultimate of corroded reinforced concrete beam, and the model forthe calculation of the flexure ductility has been built.

本文结合国家自然科学基金项目(50478032)"既有钢筋混凝土桥梁时变可靠度研究"，主要进行了以下研究工作： 1通过对48根快速锈蚀钢筋混凝土矩形截面梁(32根锈蚀梁和12根对比试验梁)数据的定性分析，得到了不同锈蚀率下，锈蚀钢筋混凝土矩形截面梁极限抗弯承载力的变化规律； 2通过对应变数据的分析，论证了锈蚀构件钢筋和混凝土的应变不再符合平截面假定的结论，并通过回归分析得出了不同锈蚀率的螺纹钢筋梁和光圆钢筋梁在极限弯矩作用下，跨中截面处钢筋应变和钢筋处混凝土应变的关系，通过构造新的几何关系，得出了锈蚀钢筋混凝土矩形截面梁计算受压区高度的表达式，既而得出了以锈蚀率为主要变量的锈蚀钢筋混凝土矩形截面梁的正截面抗弯计算建议公式，并通过试验数据加以验证； 3分析了钢筋锈蚀和混凝土劣化对锈蚀构件曲率延性系数的影响，结合钢筋屈服和极限弯矩两种状态下钢筋和混凝土的应变关系，分别得到了锈蚀钢筋混凝土矩形截面梁屈服曲率和极限曲率的计算表达式；既而推导出曲率延性系数的计算模型。

In the experiments,beam bugs were used to detect the beam currents and the beam positions,and the Cerenkov radiation generated by the electron beams interacting with a quartz plate was used to get the information of the beams.

在实验中，电子束流强度和电子柬心运动用电阻环进行测试，而电子束和石英玻璃的相互作用产生的契仑科夫辐射用来给出电子束包络和发射度信息。

In order to study initial stress and ring force transfer between steel plates and concrete in the numerical analysis of RC beam strengthened by bonding steel plates,8 scale-down models of RC beam were manufactured,their loaded whole processes were analyzed by using surface-surface contact analysis method and "birth and death" element method,and a numerical analysis method of strengthening RC beam with initial stress was proposed.

0引言钢板加固钢筋混凝土结构已在国内外受到广泛应用和研究，并且已获得了大量的研究成果，但成果主要来源于室内模型试验。由于受到试验规模的制约，目前所取得的研究成果，特别是试验成果还带有较大的片面性，不能系统地反应其真实的自然规律[1-3]。

The method utilizes an optical device which consists of polarization control elements and polarization beam splitting pieces for realizing the multi-switching of polarization or non-polarization light; in a position sequence, one polarization beam splitting piece is arranged on a main optical path at the back surface of each polarization control element, thereby commonly constituting a 'single-pole double-throw' optical switch with a controller; the controller changes the polarization state of input light beams by driving the polarization control elements according to the control logic, and the input light beams are switched to any one path on an output channel through the polarization beam splitting pieces, thereby completing the designated optical information processing function.

利用偏振控制元件和偏振分束片两种光学元件组成的光学装置实现偏振或非偏振光的多路切换；在位置序列上，每个偏振控制元件后面主光路上放置一块偏振分束片，并和控制器共同构成一个'单刀双掷'光开关；控制器按照控制逻辑驱动偏振控制元件改变输入光束的偏振态，并通过偏振分束片将输入光束切换到输出通道上的任何一路，来完成指定的光信息处理功能。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。