前后的

After comparing the image effect of homomorphic filtering, the effect of median filtering with different templates and the effect of binarizing with improved OTSU, the experiment results show that V groove laser image in underwater welding is preprocessed very well through such serial processing steps as homomorphic filter strenghening, median filtering, binarizing with improved OTSU, and thinning.

通过比较同态滤波前后效果、比较不同模板下的中值滤波效果、以及Otsu法改进前后的效果，实验表明，对水下焊接V型焊接坡口激光图片依次进行同态滤波增强、中值滤波、改进Otsu二值化和腐蚀细化一系列图像处理，取得了效果较理想的预处理结果。

The Modern scholors generally regard Dayus watercontrol project as a legend instead of historic factBy the data of uranology,the author firstly demonstrates that there were quite a lot of natural disasters about 4000 years ago caused by the nine planets in the solar system moved into one line,and among these disasters ,floodwater was the most serious oneSecondly,with the new discoveries of the geographic and archaeological works...

现代学者多将大禹治水视为中国历史上的神话传说。本文先引天文资料证明距今4000年前后确因九星地心会聚引发了各种自然灾害。在这些灾变中，尤以洪水为大。再引地理、考古资料证明此次洪水在黄河下游地区实为距今4000年前后的黄河南北改道，而改道又加剧了洪水泛滥。然后勾稽历史文献，从典籍中寻求黄河改道的线索。

Objective To study the changes in soft tissue of facial profile after orthodontic treatment with four premolars extracted in bimaxillary protrusion in adolescents.

目的 研究青少年双颌突患者拔牙矫治前后侧面部软组织的改变方法对34例青少年双颌前突患者拔牙矫治前后的18项侧面部软组织指标进行对比，通过配对t 检验来分析治疗后侧面部软组织的改变。

Patellofemoral alignment were evaluated through MRI in 12 of them. We followed up 34 Cases (37 knees) and compared patellofemoal score with prcoperation, so that we could evaluate the effects of bipolar radiofrequency in the treatment of patellofemoral malalignment.

其12例12膝手术前后进行了MRI检查，对髌股关节对合的变化进行比较分析。34例37膝手术后获得了随访，采用Kujila髌股关节评分法比较了他们在手术前后的髌股关节得分情况。

The orientation degree of nanocrystals in PC polymer was estimated by measuring the transparency spectra of unpoled and poled composite thin films.

测量了极化前后的复合薄膜的投射率并且由此算出了极化前后的光学带隙。

Methods The decalcified enamel was treated with the three agents respectively. After treatment, the microhardness of enamel surface of all samples was detected.

应用显微硬度仪检测处理前后的釉质表面硬度值，通过对比前后硬度差异反映脱矿釉质的再矿化的情况。

Secondly, with well logging of injection profile with five parameters, layering water absorptions in formations were measured. The state of water absorption, the results of water flooding, and the leakage in air casing and bypass channel were also analysed.

其次，利用注入剖面五参数测井技术，对调剖前后进行分别测试，确定了地层中各砂组、各小层的分层吸水量，分析了调剖前后的吸水状况、注水收效状况以及管外漏失和窜槽。

Based on the analyses of the flow and sediment characteristics and evolution trend of the river bed of the Fuling reach in the Yangtze River before and after the impoundment of the Three Gorges Reservoir, the water level, velocity variation and influenced range in the Fuling reach before and fifty years after the operation of the Three Gorges Reservoir with the construction of the Fuling dock and four discharge combinations are calculated by using a two-dimensional flow mathematic model.

摘要在分析长江涪陵段的水沙特性和三峡水库蓄水前后该河段河床演变趋势的基础上，运用二维水流数学模型，分析了4种流量组合情况下在三峡水库运用前和运用50年，涪陵港区码头修建前后的水位、流速变化及其影响范围。

In order to analyze the change of amphibious vehicle resistance before and after the wheels were retracted, because the configuration complexity of bodywork,and turbulent was severity about it,so the theoretical solution was very difficult,therefore the resistance of bodyworks in water was simulated and analyzed by Fluent before and after the wheels were retracted.

为了分析车轮收起前后两栖车水中阻力的变化，考虑到两栖车车体结构复杂，车体周围湍流严重，难于用理论求解，因此，利用计算流体力学软件Fluent，对车轮收起前后的阻力进行仿真分析。

The contrastive experimental of spiral atomizer which equiped injection type ejector, and the high speed photographic apparatus shot atomization effect picture of these two kinds of different structure atomizer were studied.

对螺旋雾化器加装引射式喷射器前后的雾化效果进行了对比实验研究，并利用高速摄影仪拍得了加装前后雾化效果的照片。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。