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In this paper, the propagation and focus properties for several modes describing hollow beam are analyzed, and the focus properties for hollow gaussian mode are particularly discussed. Furthermore, a new mode, high-order Bessel-Gauss mode, is put forward to describe hollow beams. The results for high order Bessel-Gauss beams propagating through lens focusing system and free space are derived by terms of Collins integral formula.

本文分析了几种描述空心光束数学模型的传输特性和聚焦特性，着重讨论了描述非中空光束的数学模型的聚焦特性；同时提出了一种描述完全中空的空心光束的新模型――高阶贝赛耳高斯模型，并且运用Collins积分公式，分析了这种新模型的空心光束的传输特性和聚焦特性。

The method is both suitable to free vibration of nonhomogeneity beams with stepped variable cross section attached concentrative mass and forced vibration of stepped beams of nonhomogeneity with variable cross section under arbitrary loads.

这种方法也适用于非均质阶梯梁在任意谐载荷作用下的强迫振动问题以及均质阶梯梁的自由振动问题。与现有的方法相比，状态矢量法具有形式简单、适应性强等优点。

The results indicated that adoption of CFRP sheet could effectively improve not only the bearing capacity and stiffness but also the safety margin of RC beams. The bearing capacity of RC beams increased with the number of layers of CFRP sheets. The most economical and effective way was using single layer of CFRP sheet.

研究表明：外贴CFRP布加固不仅可有效地提高RC梁的承载能力和刚度，而且可以大幅度地提高其安全储备，加固梁的承载力随着粘贴的CFRP层数的增加而增长，但加固1层是最经济，效果最好的。

Based on prestressed steel beams, considering effect of the method of construction to slip and stress increment, accoding to conception that procedure of calculation reflects the procedure of construction and change of structural internal force, making good use of the method of section conversion and making iteration reflect the coupling of slip and stress increment, bringing forth a method of iteration and modified stiffness to calculate the deflection of prestressed composite steel-concrete beams in normal servicing prase.

以预应力钢梁为基础，充分考虑施工方法对结构滑移和应力增量的影响，依据设计计算中反映施工过程和结构受力变化过程，通过截面换算，以循环迭代法来考虑滑移和预应力钢束的耦合作用，提出了计算预应力钢—混凝土组合梁正常使用阶段挠度变形的迭代—修正刚度法。

On the basis of local loaded experiment of external prestressing on laminated beams of concrete and theoretical analysis,we put forward the calculated formula for deformation and maximum crack width,considering the force bearing property of two stages of the laminated elements of concrete and the recent research results for beams of partly prest...

在体外预应力混凝土叠合梁现场加载实验和理论分析基础上，结合无黏结预应力混凝土梁已有的研究成果，同时考虑混凝土叠合构件的二阶段受力特性，给出了体外预应力混凝土叠合梁变形及最大裂缝宽度计算方法。通过与现场实验结果对比，表明该公式计算精度较高，可用于指导同类工程的加固设计。

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。

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。

Focusing properties of elegant cosh square Gaussian and Sinh square Gaussian beams through a thin lens are studied in detail. And intensity distribution on the axis and focusing intensity distribution are analyzed. Also focal shift of Sinh square Gaussian beams are studied.

详细研究了复宗量双曲余弦平方-高斯光束和双曲正弦平方-高斯光束通过薄透镜时的聚焦特性，分析了光束的轴上光强分布和聚焦场的光强分布，讨论了双曲正弦平方-高斯光束的焦移。

Our main work is as follows: the stable laser mode theory in uniform plasmas is extended to non-uniform plasma cases; the discussion of the sufficient and necessary conditions for laser self-focusing in uniform plasmas is developed to non-uniform plasma cases; a quantitative approach to judge the impact of different plasma density distribution on laser self-focusing is proposed; the evolution properties of asymmetric laser filed in non-uniform and uniform plasmas are discussed and mechanisms that symmetric channel-like plasmas can confine the laser centroid around the plasma channel axes and symmetrize initially asymmetric laser beams are proposed; the formation of solitary standing wave in moderate plasma density is studied by PIC simulations and can be explained by stimulated Raman scattering of laser beams in plasmas.

主要工作为：把均匀等离子体中激光的稳定模理论推广到横向非均匀等离子体情形；把均匀等离子体中激光自聚焦的充分和必要条件的讨论推广到横向非均匀等离子体情形；给出横向密度分布不同的等离子体影响激光自聚焦的定量判据。讨论了初始不对称的激光场在横向非均匀及均匀等离子体中的演化特性，并提出了具有对称腔道结构的等离子体箍缩激光质心和对称化初始不对称激光场的物理机制。用粒子模拟讨论了激光场在等离子体中形成孤立驻波的过程，认为前向受激拉曼散射是发生此现象的可能机制。

The results show that, with the same steel consumption, the longitudinal and transverse girder deck scheme is a little better in stiffness, dynamic characteristics and stability than those of the other scheme's. For the dense transverse girder deck scheme, because of no longitudinal beams, the axial forces of the tie beam and the deck slab are higher than those of the other scheme's. The improving rate of the axial force for the deck slab is about 50%. The inside and outside bending moments of the cross beams reduce to below half of the other scheme's. The longitudinal stress of the deck slab is higher on the whole and the traverse stress is less than that of the other scheme's. The maximum traverse stress of the deck slab is below 40% of the other scheme's.

研究结果表明：在材料用量相同时，纵横梁方案桥梁刚度较密布横梁方案的桥梁刚度稍大，桥梁动力特性比后者的优，其稳定性也比后者的强；对于密布横梁方案，由于不设纵梁，系梁和混凝土板承受的纵向力都较纵横梁方案的大，混凝土板增幅达50%左右，横梁面内和面外弯矩则明显减小，都低于纵横梁方案的一半，混凝土板顺桥向应力整体比纵横梁方案的高，而横桥向应力则较低，最大值低于纵横梁方案的40%。

As of Tuesday, Google's results were still censored in China.

截至周二，谷歌的搜索结果仍受中国审查。

In order to make the positive action increase and negative one decrease, the sub-forces of the social factors must be adjusted to form a centripetal force.

在这一过程中，人的主体性发挥是社会有机体健康发展的灵魂。