有规律地

In the process of building and using the mass concrete structures, because of the effect of out-side condition and themselves, some faults will form in the structure, these faults will effect the bearing capability and endurance Using nondestructive testing method to test the concrete"s quality and diagnose its healthy, which has the significant sense in assessing the safety stability and research of the administering diseasesThis dissertation mostly researched the testing methods in the mass concrete structure, discussed the principles, methods, features, sphere of application of the ultrasonic testing in the mass concrete structure with faults, used dynamic FEM to simulate the testing process, discussed when the concrete structure with cracks is under the effect of the pulse, how the elastic waves propagate and what are their changing feature, Researched the principles of the first-arriving waves" phase when the cracks" depths are not same, obtained the relation between the inversion point and the cracks" depth, which has the direction sense in the application of projects,The second part of this dissertation is CT , which used the ultrasonic wave running through the tested-substance to get arriving-time of the ultrasonic wave, then inverse the image This dissertation drawed one CT program which can well present the different little cells ultrasonic wave velocity profiles of the substance, thereby to diagnose the quality of the part of the tested-substance, CT has the better using foreground..

在混凝土结构的施工及使用过程中，由于受其自身及外界各种因素的影响，常常会产生一些缺陷，对结构物的承载能力和耐久性造成严重影响，采用无损检测技术进行质量检测和健康诊断，这对混凝土结构开展安全、稳定性评估以及病害隐患治理研究具有重要意义。本论文主要针对大体积混凝土结构缺陷的检测方法展开研究工作，重点讨论了超声波法检测混凝土结构裂缝的基本原理和方法及其特点、适用范围，运用动力有限元数值模拟其检测过程，探讨了有裂缝缺陷的混凝土结构在脉冲荷载作用下弹性波的传播及其变化特征，研究了不同裂缝深度下首波相位变化规律，得出了反转临界点与裂缝深度之间的关系，这对实际工程应用具有指导意义。声波CT是一种新的无损检测技术，它是利用声波穿透被检测体获取声波接收时间，来进行计算机反演成像的技术。本文利用直射线法编制了层析成像程序，能较好地呈现被检测物体各微小单元的声波速度分布图像，从而对检测体的质量状况作出诊断评估，具有较好的应用发展前景。

Moreover, the electromagnetic flux density and meniscus height increase in the form of chequerboard with increasing of slit number. The numerical results can exactly illuminate some experimental phenomena, and enrich the theoretical foundation of soft-contact continuous casting technology. In practice, a softcontact mold with slit number of 16 or 24 is recommended, the suggested frequency is around 20kHz, and the slit width is about 1mm.

结果表明：钢液对结晶器内的电磁场分布有很大影响；发现了磁感应强度和弯月面高度随电源频率增加而增大的频率范围、磁感应强度和弯月面高度随切缝数目增加呈&锯齿状&增大的规律；研究结果合理地解释了一些实验现象，完善了软接触结晶器电磁连铸技术的理论基础；建议在实际应用中采用分瓣数为16或24分瓣数的结晶器，电源频率应控制在20kHz左右，切缝宽度应控制在1mm左右。

Mary , a well-known Sunday painter's girl Friday , went to the art exhibition in her Sunday best yesterday and made a hit with all the gentlemen there who seemed to have Sunday-go-to-meeting manners .

在英语中，有动词和小品词（ up， down， in， out， on， off， over， away ）构成的动词短语很多，有时很难猜出它们的意义，笔者收集了常见的动词短语，通过分析小品词的意义，对这一类的短语进行分类，找出它们的规律，以便更好地掌握它们，注意有些短语意义很接近，这要结合例句和上下文掌握它们的用法。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。