查询词典 laser beam printer

The mechanical property testing shows that the seamless PLLA tubes perform excellent radial strength,which indicates that the mechanical properties of biodegradable stents made of these tubes was supposed to be excellent.PLLA and its composites were first used in preparing seamless tubes as antecedency of laser-cut biodegradable coronary stents in china.Finite element analyses of the biodegradable coronary stent model indicate the explorative design basically meets the requirement of reasonable and applicable stents.There is not such kind of research yet in domestic.Optimum laser-cuttting parameters of CO2 laser was cauculated based on experiential formula,within it,biodegradable coronary stents,especially those with complex structure would be manufacutured from seamless tubes quickly by laser microprocessing with high consistency to the design model.The processing efficiency of the CO2 laser demonstrated in experiential formula by us will play an important guiding role in manufacturing biodegradable stents by laser-processing.Our stents that ascribed to laser-cutted,slotted tube stent are proved to be biodegradable, self-expandable and good biocompatible,basically reach the international level on the aspest of manufacturing procedures and design.

研究结果表明：壳聚糖改性材料综合性能优于纯PLLA，更适合于作为可降解冠脉支架的原材料；自主设计的探索性自膨胀管状闭环型可降解冠脉支架的性能符合冠脉设计要求，设计、验证生物可降解冠脉支架模型的研究在国内还未见报道；制备的改性PLLA无缝管的力学性能优越，可通过激光切割获得冠脉支架，这是国内首次采用聚乳酸材料来制备通过激光加工出可降解冠脉支架的无缝管；二氧化碳激光器加工精度能达到加工要求，加工出来的血管支架名义设计与实测值误差小，实现了冠脉支架、尤其是带有复杂外观设计冠脉支架的快速化、规范化加工，对二氧化碳激光器加工聚乳酸材料的效果研究在国内外属于首创，获得的经验公式对日后的深入研究有重要的指导意义；制备的支架为激光切割管状闭环型冠脉支架，支架外观设计、支架加工手段、支架的性能都基本接近国际水平，支架样品符合设计的理念，可以实现自膨胀功能。

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。

Diamagnetic loop is new beam diagnostic technology, it measures electromagnetic parameter-magetic moment that is brought while beam is transforming, by measuring magnetic moment we can calculate beam radius. Diamagnetic loop is non-intrusive diagnostic system, it can diagnose beam radius on line and it can diagnose beam emittance and obliquity cooperating with other technology such as three gradient method and beam bugs.

反磁回路法是国际上近年来发展起来的一种新的束流诊断技术，它是通过测量束流传输过程中产生的电磁场参数对束流的特性——束流半径进行诊断的，是一种非阻挡型的诊断系统，可以在线诊断束流情况，与其它方法相配合还可以得出束流剖面的其它参数，具有结构简单、抗电磁干扰能力强、安装使用方便可靠等特点。

For the structure stress condition, the dead load is born mainly by continuous rigid-frame, and the live load is born by both the arch rib and the main beam, the force separately bora by the arch rib and the main beam is influenced by the whole rigidity of beam and arch, and by areas of flexible hanger rod, the structure perforce is no longer same with the common beam and arch, and the inner force analysis progress is more complex to the common bridge system, especially, the multi-direction stress analysis to the combination area of pier、 arch and beam is very difficult, for such reasons, so it is very necessary and important to have stress performance analysis in the combination area of pier、 arch and beam.

从结构受力情况来看，梁体自重主要由连续刚构承受，活载由拱肋与主梁二者共同承受，各自承受力的大小受梁、拱相互整体刚度、柔性吊杆面积的大小影响，结构性能已不同于一般的拱与梁，结构内力分析的过程较一般桥梁体系较为复杂，特别是墩、拱、梁结合处的多向受力状况的分析难度更大，所以对该桥式结构，墩、拱、梁结合部的结构受力特性进行进一步地理论分析测验研究也就显得十分必要和迫切了。

The main way of the method of beam grid is to simulate the top structure with a equivalent beam grid, and concentrates the scattered bending rigid and tension rigid in slab or box beam into the close equivalent beam grid, and the longitudinal rigid of the real structure is concentrated in longitudinal beam rigid, and the lateral rigid is concentrated in lateral beam rigid.

梁格法的主要思路是将上部结构用一个等效梁格来模拟，将分散在板式或箱梁每一区段内的弯曲刚度和抗扭刚度集中于最邻近的等效梁格内，实际结构的纵向刚度集中于纵向梁格构件内，而横向刚度则集中于横向梁格构件内。

Those ions will perform stable oscillation nearby the beam orbit while their mass is larger than a critical mass. The accumulation of trapped ions nearby the beam orbit, interacting with beam, can cause the tune shift of beam, blowup of beam emittance, increase of local vacuum pressure, and can even lead to the occurrence of beam instability.

这些被俘获的离子在束流轨道附近的积累并和束流的相互作用，会引起束流振荡频率的漂移和展宽、束流发射度的增加、局部真空度的恶化等各种负效应，有时甚至会导致束流不稳定的发生，从而影响储存环的正常工作，在这种情况下采用离子清洗方法将离子清洗掉对保证储存环的长期、稳定的运行是必要的。

Five novel torsion-mirror optical actuators including double-beam thickness differential structure with single torsional axis, double flexible folded-beam structure with single torsional axis, double-beam vertical torsion comb structure with single torsion axis, four-beam differential compound-micromirror structure with double torsional axis and the combined structure of the four basis forms above, are brought forward. All of these devices could be fabricated by the same silicon micromachining process we have developed. The deformation compensation design with local enhancement for the thin torsional beam which is the key structure of these devices is also put forward to improve the reliability. The three-dimension solid model and two-dimension reduced order model of the torsion-mirror optical actuator are established and then the numerical simulations for evaluating the device characteristics of the statics, dynamics, electrostatic field, mechanical and electrostatic coupling, fluid and solid coupling are carried out to optimize the structure design. Furthermore, three optical fibre clamping structures which could be integrated monolithicly are designed and analyzed to improve the optical coupling capability. 4. Three flexible process flows combined with bulk silicon micromachining and surface silicon micromachining are brought forward to fabricate these novel single-crystal silicon or polysilicon torsion-mirror optical actuators by using the same lithography masks for both SOI wafer and regular silicon wafer. A series of important process experiments are carried out to optimize the process parameters and the process flows. Some novel and typical process phenomena which occurred during the microfabrication are analyzed and then the corresponding solutions are put forward. 5. A MEMS dynamic testing system which exploit blur image synthetic technique, stroboscopic image matching technique, stroboscopic mirau microscopic interferometry technique and microscopic laser dopper vibrometer technique is set up to measure three-dimension and six-freedom micro motions of any MEMS devices with nanometer resolution.

在对硅微机械扭转镜光致动器的光机电特性系统地理论研究的基础上提出了硅微机械扭转镜光致动器的结构设计准则。3、提出了单轴双梁厚度差分结构、单轴双柔性折叠梁结构、单轴双梁垂直扭转梳齿结构、双轴四梁差动复合微镜结构以及以上四种基本结构组合后的衍生结构等五种工艺加工技术兼容的新型的硅微机械扭转镜光致动器，对器件关键结构薄厚度、高耐疲劳扭转梁进行了局部加强的变形补偿设计，建立了器件的三维实体模型以及两维降阶模型，对提出的新结构硅微机械扭转镜光致动器进行了系统的静力学、动力学、静电场、力电耦合和流体固体耦合的建模仿真与优化设计，同时设计并分析了三种可实现单芯片集成的弹性光纤定位夹紧结构。4、提出了组合体硅微加工技术与表面硅微加工技术、兼容同一套光刻版图、可分别基于SOI 晶片和普通Si 晶片、适应于制造提出的各种新结构单晶硅和多晶硅硅微机械扭转镜光致动器的三套柔性加工工艺流程，开展了一系列重要工艺步骤的单项工艺试验，对工艺流程与工艺参数进行了优化，针对加工过程中出现的具有普遍意义的典型工艺问题进行了讨论和分析，并提出了解决方法。5、创新性地将模糊图像合成技术、频闪图像匹配技术、频闪Mirau 显微干涉技术与显微激光多普勒测振技术有机结合，建立起了一套周期运动测量与瞬态运动测量相结合、单点运动测量与全视场运动测量相结合、满足不同MEMS 器件各种动态测试要求的集成的MEMS 三维六自由度微运动精密测量系统。

The measuring device is structured by including a He-Ne laser; a beam expander, a soft aperture slot and a off-axis parabolic mirror to be measured are arranged in turn along the direction of the emergent laser beam direction of the He-Ne laser; a standard cross hair and a micro objective are arranged in turn on the direction of the reflected beam of the off-axis parabolic mirror; the micro objective is arranged on the focus of the off-axis parabolic mirror; the focus is imaged on an area array CCD; the output end of the area array CCD is connected with a computer; the off-axis parabolic mirror is fixed on a five-dimensional electric adjusting frame.

一种离轴抛物面镜点聚焦能力测定装置和测定方法，测定装置的构成包括：一台He-Ne激光器，沿该He-Ne激光出射激光束方向依次设置扩束器、软边光阑和待测的离轴抛物面镜，在该离轴抛物面镜的反射光束方向依次设置标准叉丝和显微物镜，该显微物镜位于所述的离轴抛物面镜的焦点，所述的焦点成像于面阵CCD上，该面阵CCD的输出端接计算机，所述的离轴抛物面镜固定在一五维电动调整架上。

The invention also provides a method for producing the laser beam focusing integer type parabolic mirror formed in one piece using a rotary type high accuracy machine tool, with features of simple technique, increased capacity of reflector for proofing the high power laser beam and heat-sinking capability, and improved focusing quality of laser beam.

本发明还提供制造所述激光光束聚焦整型抛物面镜的方法，该方法利用回转型高精车机床一次成型加工，制造工艺简单，可提高反射镜耐高功率激光束的能力以及散热能力，改善激光束的聚焦质量。

Ponderomotive force of laser beam propagating in plasma could become stronger as the intension of laser beam strengthening , and in fluid mechanics ponderomotive force is related to implicate term, so implicate term could become stronger as laser beam's strengthening and couldn't be ignored.

当在等离子体中传播的激光脉冲达到一定强度时，有质动力会变得比较强。而在流体力学方程中有质动力一项与牵连项相关。因此当激光达到一定强度的时候，流体方程中的牵连项也会变得比较强，不可以被忽略。

We are forbidden from giving money to these shoeless, skinny children, as this will perpetuate begging.

向光着脚，骨瘦如柴的孩子施舍是不可以的，因为要招来无休无止的乞讨。

It would be hard not to fall victim to some sharpeyed policeman.

要想不被某个目光锐利的警察抓到，谈何容易。